1
introducing
Plastics are all around us today and help to make our personal lives cleaner,
easier, safer, more convenient and more enjoyable.
The use of plastics is increasing all the
time as they replace materials such as
metal, wood, paper, ceramics and glass
in a wide variety of uses. There are
also new roles which only plastics
can fulfil.
The motor car is a good example of
a product in which plastics are now
extensively used. Over the last 20 years,
the use of plastics in cars has increased
by 114 per cent and it is estimated that
without plastics today’s cars would be
at least 200kg heavier. Weight savings
achieved through the use of plastics
have enabled parts, such as the chassis
and drive shaft, to be made lighter. It is
estimated that over the average lifespan of a car of 150 000km, this
lightweighting has contributed to a
reduction in fuel consumption of
around 750 litres. In turn, this reduces
oil consumption by approximately
12 million tonnes and CO2 by
ACTIVITY 1
1 Think of at least three objects which, a few
years ago, would have been made
of other materials and which are
now commonly made of plastics.
2 For each object you listed, see if there are
any obvious advantages of the plastic over the
other material. Give reasons why you believe
plastics are now used.
30 million tonnes per annum in
Western Europe.
But what are plastics? Why are
they so useful and so widespread?
Why do they behave as they do?
What is their chemical structure?
Many materials we use every day
are made of polymers. These are large,
long molecules constructed of smaller,
shorter molecules called monomers.
This diagram shows the structure of a
monomer and a polymer
ACTIVITY 2
1 This picture shows a typical
modern car. Which parts are made
of plastics materials? What
advantages do you think plastics
have over metal? Think of
safety
economy
style
colour
cost
Polymers can be natural or synthetic.
Natural polymers are common in
animals and plants. Much living tissue
is based on polymers - for example,
proteins in animals and carbohydrates
in plants. A lot of our food is based
on polymers - for example, fibre, grain
and meat. Plants and animals also
produce non-living materials based on
polymers. These are usually produced
2 It is estimated that a 1000kg
car, containing 100kg of plastics,
would use 4% less fuel than a car
made of more traditional
materials. If a car uses 2000 litres
of fuel each year, costing 70p per
litre, how much money is
saved through the use
of plastics?
monomer
polymer
ACTIVITY 3
1 Look at these pictures of
objects made from synthetic
polymers. Try to decide
whether the polymer is a solid
plastic material or a fibre.
Whether a plastic is a solid material or
whether it is a thread-like fibre depends
only on how it has been produced. From
now on, the word plastics will be used to
describe all such materials.
as fibres and then have to be
processed to produce materials such
as threads and fabrics.
Synthetic polymers are made
mainly from petroleum. This is
processed in an oil refinery to
produce basic chemicals known as
monomers. The monomers are then
turned into polymers. Some polymers
are turned into a solid plastics
material, and others into textile
fibres. Some can be turned into
either, depending on how they are
processed.
of plastics
The history
As we enter the 21st century it is
clear that plastics are now an integral
part of our lives. From the packaged
products we purchase, the transport
we use and the buildings we live and
work in, to the sports equipment we
use and the advanced medical
technology employed to keep us fit
and healthy, plastics have become
indispensable.
Plastics products were first made
in 1862 from plant materials.
Cellulose fibres in the form of cotton
wool were treated with nitric acid to
form cellulose nitrate (‘Celluloid’),
which was used to make objects such
as ornaments, knife handles, boxes,
cuffs, collars and film for movies.
In 1909 a new source of raw
materials was found - coal tar. This
provided the ‘Bakelite’ plastics, used
for electrical insulation and the cases
for cameras, early radios and even
jewellery.
In the early years of this century,
chemists began to understand the
reactions which they were observing,
thus accelerating the search for new
types of material. In the 1930s the
manufacture of plastics from chemicals
produced from petroleum began, and
polystyrene, acrylic polymers, and
polyvinyl chloride were produced,
although their use grew only slowly.
Nylon was discovered in 1928, and
entered production in the late 1930s. It
was produced as long filaments which
could be spun and woven or knitted.
The production and manufacture of
other plastics materials - low density
polyethylene, polyurethane, polyvinyl
chloride (PVC), PTFE, polyesters,
silicones, epoxy resins - grew during the
1940s. Polycarbonates were added in
the 1950s. High density polyethelene
(HDPE) and polypropylene were added
in the 1960s.
The1970s saw the arrival of the
‘third generation’, high-tech,
performance plastics which built on
previous developments. These included
new polyamides and polyacetals.
Innovation continued throughout the
80s and 90s, with new polymers being
created to meet specific design
challenges. For instance, recent
advances in catalyst technologies have
allowed even better control of a
polymer’s molecular structure and
provide improved physical properties.
For example, a new generation of
metallocene catalysts allow much
stronger polyethylene films to be made
which are tougher and more
transparent while using even less raw
materials.
Today, more than 700 types of
plastic are produced which fall into
18 main polymer families. Readily
available, versatile and economic to
manufacture, plastics are used to
produce both hi-tech and everyday
objects. A regular consumer survey
shows that the most positive attitudes
towards plastics are in connection with
innovative, hi-tech applications.
ACTIVITY 4
80
1 Describe the shape of this graph.
2 Why do you think the graph changes shape so
much during the 1950’s?
70
60
3 What happened in the early 1970’s to make
the graph change direction so sharply?
50
4 Extend the graph to the year 2010. What does
this suggest the level of production will be?
40
The growth in the production of
plastics across the world (tonnes m)
30
20
10
1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
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2
the raw
The raw material for plastics is crude oil, a complex mixture of thousands of
compounds. To become useful, it must be processed. Around 4% of the
world’s production is turned into plastics.
These fractions are still complex
mixtures of compounds and no
chemical changes have yet taken
place. They need to be chemically
altered to make them into more
useful products with different melting
and boiling points and different
chemical properties. There are two
types of process:
Other petrochemicals 4%
Heating,
electrical &
energy
42%
Transport
45%
Because the compounds in crude oil
have different masses, and therefore
boil at different temperatures, it is
possible to separate them by a process
known as fractional distillation.
Plastics 4%
All other 5%
The mixture is separated into
fractions, not into individual
compounds. Fractions contain a
mixture of compounds whose boiling
temperatures are similar.
The diagram on page 2 shows the
fractional distillation process. It is
mainly the naphtha and gas oil
fractions which are used for further
processing to make products such
as plastics.
Cracking
Cracking breaks large molecules into
smaller ones which are more useful –
and therefore of greater value. For
example, very high boiling point
fractions are cracked to produce
ACTIVITY 1
Most compounds in crude oil are hydrocarbon molecules –
they contain carbon and hydrogen atoms only. These
diagrams show a few of the compounds which are found in
crude oil. Diagram (a) shows ethylene.
A range of
molecules showing
different ways in
which chemical
bonds are formed
between atoms.
b
a
c
1 Draw the formula of each of these compounds in the
following form
CH2=CH2 This is the structural formula of ethylene
2 And then write the formula in this form
d
C2H4 This is the molecular formula of ethylene
e
The mass of a molecule depends on the number of carbon
and hydrogen atoms in it. A carbon atom has a mass of
12 units; a hydrogen atom has a mass of 1 unit. In the
example shown below, the mass of an ethane molecule,
C2H6, is [2x12] + [6x1] = 30 units
3 Work out the mass of the molecules shown here (a-g).
4 If the boiling point of the compound increases as its
mass rises, arrange the compounds in order of increasing
boiling point.
g
f
represents a carbon atom
represents a hydrogen atom
represents a chemical bond
This diagram shows the fractional distillation process. It is
mainly the naphtha and gas oil fractions which are used
for further processing to make chemicals such as plastics.
refinery gases
fractionising
column
40°C
gasoline
110°C
heater
naphtha
180°C
kerosine
crude
oil
260°C
gas oil
340°C
long residue
gasoline and gas oil fractions. Today,
most cracking uses catalysts, but some
heat treatment still occurs.
Reforming
Reforming changes the internal
structure of molecules to produce
different compounds with a greater
usefulness – and therefore higher
value. By altering conditions – such as
temperature, pressure and the catalyst
– the cracking and reforming
techniques can now be controlled to
produce exactly the blend of
compounds which will be most useful
at a particular time.
Naphtha is cracked by mixing it
with steam and heating it to 800°C.
It is cooled rapidly to 400°C, causing
chemical changes. The mixture of C6
to C10 compounds is converted to a
small number of C2, C3 and C4
compounds which contain carboncarbon double bonds, C=C.
The simple compounds are often
known as ‘basic chemicals’ – many of
these are shown on this card in
Activity 1.
All the basic chemicals are small
molecules containing between two and
seven carbon atoms. It is these
molecules which are the ‘monomers’
from which the ‘polymers’ are then
made.
The small monomer molecules are
reacted together to form a polymer
rather like paper clips to form a chain.
In order to make the monomers react
and join up together, small amounts
of special catalysts are added to the
polymerisation reactor.
Polymer manufacturing has
become increasingly sophisticated in
recent years, as researchers have
developed new compounds to meet
the needs of specific design
challenges. For example a new family
of catalysts known as metallocenes
give greater control over how
monomers join up in a more ordely
fashion. This can make the resulting
plastic much stronger and transparent.
ACTIVITY 2
1 One of the simplest synthetic polymers is polyethylene.
This is made from ethylene.
The structure of
ethylene is:
H
H
C
H
Part of the structure
of polyethylene is:
C
H
H
H
H
H
H
H
C
C
C
C
C
C
C
H
H
H
H
H
H
H
H
List the structural differences between
the two molecules.
2 The monomers react by the end of one
molecule bonding to the end of another. In this
way chains are formed. This is rather like
paper clips being linked together. Draw your
own picture of how this chain formation
takes place.
Polymer chains have very different properties to monomers
Monomers
Polymers
reactive compounds
unreactive compounds
small number of carbon atoms in a
molecule
very large number of carbon atoms
in a chain
usually a gas or a liquid
always a solid
relatively cheap compounds to
produce
nearly always more valuable to sell
of little use as they are
very useful once they have been
processed
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3
polymers
and
Eight of the most important polymers are produced from only three basic
chemicals which come from naphtha.
Ethylene C2H4
to form high density polyethylene (HDPE), low density polyethylene (LDPE) or linear low density
" polymerisation
polyethylene (LLDPE)
polymerisation to form polyvinyl chloride (PVC)
" reaction with chlorine to form chloroethene
polymerisation to form polystyrene (PS)
" reaction with benzene to form styrene
further reaction and polymerisation to form polyethylene
" reaction with oxygen to form ethene oxide
terephthalate (PET)
Propylene C3H6
" polymerisation to form polypropylene (PP)
further reaction and polymerisation to form
" reaction with oxygen to form propylene oxide
polyurethanes (PU)
" Ethylene and propylene can be polymerized together to make a rubber which can also help make polypropene even tougher
Butadiene C4H6
" polymerisation to form polybutadiene which is a synthetic rubber
ACTIVITY 1
6834
5782
PP
HDPE
965
630
PET
PS
2194
2146
1779
PVC
604
433
LLDPE
1749
4195
3861
3718
1692
1429
899
LDPE
1281
3107
4982
4432
5370
5401
5251
4829
4920
2 Summarise in one sentence
how sales of plastics generally
have changed over the period.
3 Suggest reasons for the
changes you have reported.
4727
4698
1 Describe how sales have
changed for each of the plastics.
’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98
4544
The table to the right shows the
total sales of the major plastics by
Western European manufacturers
from 1992 to 1998 (figures show
thousands of tonnes sold).
Although there are many different examples of plastics, they fall into two distinct categories:
Those which soften on heating and then harden
again on cooling
Those which never soften once they have
been moulded
These are called thermoplastic polymers because they
keep their plastic properties
These are called thermosetting polymers because once
set into a shape, that shape cannot be altered
These polymer molecules consist of long chains which
have only weak bonds between the chains
These polymer molecules consist of long chains which
have many strong chemical bonds between the chains
The bonds between the chains are so weak that they can
be broken when the plastic is heated
The bonds between the chains are so strong that they
cannot be broken when the plastic is heated
The chains can then move around to form a different
shape
This means that the thermosetting material always
keeps its shape
The weak bonds reform when it is cooled and the
thermoplastic material keeps its new shape
The bonding process. When thermoplastic polymers are heated they become flexible. There are no cross-links and the
molecules can slide over each other. Thermosetting polymers do not soften when heated because molecules are crosslinked together and remain rigid
It is clear from this that the chemical
bonding in a polymer and the shape of
the polymer will affect its properties.
Most plastics made from the
basic chemicals that come
from naphtha are thermoplastic
ACTIVITY 2
1 Imagine that you are a small part of a thermoplastic polymer. You are part
of a lump of plastic material which is waiting to be processed into a cup.
➔ You have strong chemical bonds along the polymer chain to parts of the
molecule next to you; you also have some weak bonds across to parts of the
polymer which are positioned near to you. The weak bonds keep the plastic
material solid and rigid.
➔ As part of the manufacturing process, the plastic material is warmed to
make it soft and pliable; then squeezed in a press into a new shape; then
allowed to cool and solidify into the new shape.
➔ Describe what happens to your part of the polymer as this processing
takes place.
➔ Use words, a diagram, or a cartoon to do this.
Examples are polyethylene
(HDPE, LDPE and LLDPE),
polypropylene (PP), polystyrene (PS),
polyethylene terephthalate (PET), and
polyvinyl chloride (PVC)
Common examples of
thermosetting plastics are
polymers based on formaldehyde
(Bakelite was the earliest example)
Examples are
melamine/formaldehyde
(MF), urea/formaldehyde (UF),
phenol/formaldehyde (PF) and
polyurethane (PU)
Epoxy glues are also
thermosetting plastics
There are two ways of producing polymer chains:
n
Condensatio
reactions
Addition rea
ctions
The polymer is made from one
monomer e.g. A-A produces
A
A
A
A
A
A
The polymer is made from two
monomers e.g. A-A and B-B produce
A
A
A
In addition reaction, chains are
formed from one small molecule. The
monomer always contains a carboncarbon double bond.
Most thermoplastic plastics
C
C
made from naphtha are
addition polymers. e.g. polyethylene,
polypropylene, polystyrene.
B
B
A
A
B
B
A
Some thermoplastic polymers are
condensation polymers. Examples are
Nylon and polyethylene terephthalate
(PET).
Nylon belongs to a class of polymers
called polyamides. Nylons are produced
by condensation polymerisation. Two
monomers which can produce Nylon are:
In condensation reactions, chains are
formed from two small molecules.
During the reaction a small molecule
such as water is formed and removed
(condensed out). All thermosetting
polymers are condensation polymers,
for example, formaldehyde-based
plastics and epoxides.
H
H
H
H
H
H
H
H
N
C
C
C
C
C
C
N
H
H
H
H
H
H
H
H
H
H
H
H
C
C
C
C
C
O
H
H
H
H
O
C
O
O
H
H
ACTIVITY 3
1 Write down the molecular formula of each of the
compounds shown above, in this form:
CxHyNz
and CxHyOz
The first step in the polymerisation is the two monomers
reacting together to form a dimer. In this reaction a
molecule of water H2O is produced from the H of one of the
NH2 groups and the OH of one of the COOH groups.
2 Draw a diagram of this dimer.
3 Write down the formula
of each of these compounds
in this form:
CxHyOzNw
This table shows the main plastics and gives examples of some of their uses.
Plastic
Uses
High density polyethylene HDPE Dustbins
Bottles
Pipes
Low density polyethylene LDPE
Bags and sacks
Bin liners
Squeezable detergent bottles
Polypropylene PP
Margarine tubs and
food wrappings
Garden furniture,
crates, suitcases
Telephones
Car bumpers
Polystyrene PS
Food containers
Computers
Video and audio cassettes
Polyvinyl Chloride PVC
Blood bags
Credit cards
Window frames and pipes
Oven-proof trays
Anorak and duvet filling
Sports shoe soles
Roller skate wheels
Polyethylene Terephthalate PET Fizzy drinks bottles
Polyurethane
Upholstery
Acrylics (e.g. Perspex)
Sink and bathtubs & tap tops Protective glasses
Car light covers
Polycarbonates
CDs
Firemen’s helmets
Car headlights
ACTIVITY 4
1 Find out more about the uses of plastics. Suggest two properties which PET has which the other plastics do not have.
2 What special properties do you think that polypropene has, if it is used as a wrapping for food such as biscuits and crisps?
3 Look at the uses of the two forms of polyethylene. From your knowledge of the different things which the two plastics are
made into, list the main differences in their properties.
4 Think about these objects which are all made from polyethylene:
➔ toys ➔ pipes ➔ film ➔ wrapcoatings for cardboard containers ➔ petrol tanks in cars ➔ electrical cable ➔ coatings
Which is likely to be made from the high density form, and which from the low density form? Why?
5 Consider PVC window frames. Suggest reasons why PVC compares favourably with other materials used for window frames.
Try and find out why PVC is used rather than other traditional materials.
6 Design an investigation to test the effectiveness of the plastic used to wrap biscuits. Begin with a clear statement of what
you wish to test. Now design a simple method of investigation.
The family of materials which form
plastics has a wide variety of different
properties. Some resist high pressure
and extremes of temperature, some
resist air and moisture. There are
different forms of the same basic
plastics type which can be stiff or
flexible and so suitable for particular
applications.
Plastics’ properties can also be
tailored by the use of additives (see
card 4).
Polymers are converted into
plastics products in
seven main ways.
These are listed
here. A brief
description of the
different methods
is given and a list
of typical products.
1
Injection moulding
The plastic is first heated, then
the soft polymer is
forced under
pressure into a
cool, closed mould
(containers, lids,
footwear, crates,
gear wheels).
5
Blow film extrusion
Soft polymer is forced into a
tube-shape. This is blown up
with air and either heat sealed or
slit (bags, film).
2
Compression moulding
The polymer is placed in a mould and
pressure applied to make the plastic
take up the shape of the mould
(electrical plugs and sockets).
3
Blow moulding
The warm, soft polymer is blown
into the shape of a mould by
compressed air or steam (bottles,
containers).
4
Rotational moulding
Plastics powder or paste is heated
inside a closed mould which is
rotated until the walls of
the mould are covered
with an even layer
of polymer (large,
hollow items such
as litter bins, fuel
tanks, drums).
6
Extrusion and
extrusion coating
The materials are heated, compressed,
and extruded through a die of the
desired shape. Materials can also be
coated with soft polymer
and then passed
between rollers to
give an even coating
(coatings on food
and drink containers).
7
Calendering
Heated polymer is fed between
two rollers which squeezes it
into a thin sheet (flooring,
tiles, panelling, sheeting).
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4
the
properties
of
Today, plastics provide an environmentally sound and cost-effective
solution for many design challenges.
Industries, especially the hi-tech ones
such as aerospace, medicine,
computing and communications, rely
on new plastics materials for progress
in engineering and design. Plastics are
often superior to any other materials
in these fields. Many new
developments would not in fact be
possible without them.
Think about the clothes we wear, the
houses we live in and how we travel.
What about the toys we play with,
the televisions we watch, the
computers we use and CDs we listen
to? Whether we’re shopping in a
supermarket, having major surgery or
merely brushing our teeth, plastics are
an integral part of everything we do.
Why are plastics so widely used in all
our lives? It is because they are:
➔ safe and hygienic
➔ tough and durable
➔ lightweight, cost-effective and
convenient
Safe and hygienic
ACTIVITY 1
1 Plastics do not usually conduct electricity. Think of as many different
ways in which this property is used in the home or at work.
2 A lot of the plastics used to package foods are transparent. How might
this increase food safety?
3 Plastics are widely used in hospitals. Look at this picture. What are the
particular advantages of using plastics in this way? Think of the advantages
that cheapness of production brings.
4 Plastics are likely to be safer than glass because they do not break, and
safer than steel because they do not rust and are less likely to have jagged
edges. Can you think of objects made from plastics which might pose a
hazard to people or animals if not disposed of sensibly?
5 Some plastics can withstand very high temperatures, why might this be
➔ good insulators
useful?
➔ flexible and adaptable
6 Some plastics are waterproof and resistant to attack by chemicals.
➔ capable of re-use
➔ supportive of innovation
Think of ways in which these properties are useful to us.
Tough and durable
ACTIVITY 2
1 Around 30-50% of food
produced in developing countries
is wasted before it reaches the
consumer, whereas in western
Europe this figure is only 2-3%.
Modern plastics packaging plays a
part in this. What other factors
might be responsible for this wide
difference?
2 Look around at home in the
kitchen or bathroom – or in a
supermarket. Find as many
different ways as you can in which
plastics add to the safe use of
other things.
3 By weight, plastics account for
about 50% of the packaging of
food sold in supermarkets, yet
only 17% of packaging waste by
weight is plastics. Look at these
pictures and think of the food you
buy yourselves. Make a list of
different types of packaging for
food. Think in particular of
examples of how shape is used as a
means of protection.
4 Expanded polystyrene is an
alternative to corrugated
cardboard as a protective
packaging material. Design an
investigation to compare the
effectiveness of the protection
offered by the two materials
against penetration by a sharp
object such as a screwdriver. You
will need to think of the quantity
of each material used to provide a
fair comparison. Discuss your
ideas before you begin the
investigation.
5 Bubble-wrap is widely used to
protect delicate objects such as
crockery. Just how effective is it?
How much protection can it give
to an egg? Design an investigation
which compares the amount of
protection given to the shell of a
hard-boiled egg as the amount of
bubble-wrap used changes. Begin
by thinking of ways in which you
can carry out the investigation.
,
c
Lightweight cost-effective and onvenient
ACTIVITY 3
1 Suggest why using bottles
made from plastics on jet aircraft
can save up to £6000 per year on
the cost of running an aircraft.
2 What else might you need to
know about the plastic bottles
before you could say whether the
real saving was £6000? Explain
how it might be more or less
than this figure.
3 When faced with a choice of
using plastic or paper bags which
do you choose? Why? What does
it depend on? Make a list of the
advantages of both paper and
plastic bags for holding fruit and
vegetables.
4 Compare the masses of
plastic and paper bags which are
used to carry fruit and
vegetables. First of all decide
how you will ensure that your
test is a fair one.
5 Looking at your results,
discuss what the impact would
be on the mass of packaging used
if we had to use paper bags all
the time.
6 Compare a soft drink carried
in a plastic, glass, metal, and
card container. Measure the
masses of the total package and
the masses of the liquids they
contain. Make a chart showing
the percentage of the total mass
which is taken up by the
packaging material.
7 Compare a one-litre drink
packed in glass and one packed
in plastics. Make a list of the
differences in the use of energy
as it moves:
➔ from the factory to
warehouse to storage in the
shop
➔ from storage in the shop to
the shelves
➔ from shelves to checkout to
home and storage
8 Now do the same but compare
metal and card drinks packaging
with plastics. Are these likely to
be similar to glass or plastics?
Why?
9 Compare the four materials
again. Think of other advantages
and disadvantages of each one.
10 Now summarise the
advantages and disadvantages of
using plastics as containers.
Think of energy savings, the
amount of raw materials needed,
other environmental issues such
as pollution and waste, and the
impact on our lives.
Good
insulators
ACTIVITY 4
1 Plastics are widely used in cups,
mugs and beakers, at home and in
vending machines. You know that
various plastics materials conduct
heat to different extents. Design an
investigation to see how the
material used affects the rate at
which heat is lost from a cup containing hot water. Try to use expanded
polystyrene, a thin-walled plastic cup and a paper cup. You will need the
cups, a thermometer and a clock or watch that records seconds. Discuss
ways in which you will make this a fair comparison.
2 Plastics are normally poor conductors of electricity. Look around your
home and make a list of ways in which plastics are used in objects with
an electrical power supply. Looking back in time, would some of these
objects previously have been made of other materials? See if you can
identify the material which plastics have replaced.
Flexible and
adaptable
➔ UV absorbers protecting against
decomposition by ultra-violet
light.
The properties of everyday plastics
are different from those of the basic
polymers. A wide range of additives
is used to give plastics the required
properties. They are ‘designer’
materials – we are able to create
exactly what we want from the raw
materials.
➔ Flame retardants reducing the
flammability.
The additives used include:
➔ Blowing agents which break
down at high temperatures
(above 200°C) to release gases
such as nitrogen or carbon
dioxide. When this happens inside
a plastic in a mould, a foam is
produced.
➔ Pigments incorporated into
plastics to add colour.
➔ Impact modifiers to ensure that
plastics don’t crack or break when
they are knocked or bumped.
➔ Anti-static agents to reduce the
amount of dust and dirt which
adheres to the plastic due to
static electricity.
➔ Mineral fillers increasing rigidity
and improving the properties of
electrical insulation. Inert
materials such as talc, chalk and
clay are used.
➔ Anti-oxidants used widely
prolonging plastics’ life by
preventing reaction with
oxygen and breakdown of the
polymer chain.
Capable of
re-use
Today, everyone is more aware of the
need to act more responsibly to protect
our world for the future – a drive
towards sustainable development. This
means acting in a way which does not
limit the range of economic, social and
environmental options available to
future generations.
Ensuring we use our valuable
resources wisely is an important
consideration for all of us. Re-use is
one way of achieving this. But first we
have to make sure we use as little
natural resources in production and
use as possible.
Plastics make the most of valuable
resources by using the minimum
amount of raw materials and energy
during manufacture and processing.
Plastics only consume a small
fraction - 4 per cent - of the world’s
oil. Today, plastics are lighter, yet
stronger and more adaptable than ever
before, thanks to continuing
technological innovation. This means
that product for product,
proportionally less of the world’s oil
and energy resources are being used
with lower overall impact on the
environment.
The versatility of plastics. The
plastic wrapping is used to store and
safeguard this frozen meal. The plastic
wrapping is removed and the meal can
be quickly reheated in a microwave
oven using the plastic container and
can then be eaten on the plastic plate.
ACTIVITY 5
1 Look at what happens to
plastics which come into the
home. How many are used
again – and what for?
How many are disposed of –
and how? Which are re-used
and which are thrown away?
Why is this?
Innovation
supporters
Throughout their history, plastics have
enabled designers to innovate, to
improve existing products and to
create new ones that improve our
quality of life and minimise
environmental impact.
In every aspect of our lives we
have benefited from these
innovations. For example, the
enhanced performance of the sports
equipment made with plastics has
allowed athletes to set themselves
ever more challenging records to
break. In medicine, plastics not only
provide an alternative to traditional
materials for garments and products
improving hygiene and safety, but
they have enabled ground breaking
developments in micro-surgery.
Plastics packaging has
significantly improved the
convenience of buying food for one
person with microwavable packaging
for ready meals. And the shelf life of
packaged fresh food has been
lengthened with oxygen-scavenging
films. Refill pouches for detergents
have significantly reduced the
packaging to product ratio found on
supermarket shelves.
They’ve contributed to increased
comfort, safety and energy efficiency
of many forms of transport, from cars
and bikes to planes and trains.
Providing a lightweight alternative to
conventional materials, they conserve
natural resources in manufacture,
contribute to reduced fuel
consumption and ultimately limit
environmental impact. Plastics have
also played a crucial role in
the development of electric
car technology and
innovations such as
airbags in cars and the
aerodynamic nosecone
of high-speed trains
like the Eurostar.
Communications
has been completely transformed by
plastics. With mobile phones, palmtop computers, the internet and
digital technology, we can access
information more easily and contact
people while on the move. Internet
usage is forecast to continue growing
at more than 300 per cent a year.
Although polymer optical fibres have
been available for 30 years, their
usage has increased exponentially in
line with the demand for costeffective global communications.
If anything, the pace of
innovation is increasing. Designers in
every industry are experimenting
with plastics’ capabilities. Where the
polymer doesn’t yet exist to meet the
designer’s needs, researchers are
developing new types of plastics.
Plastics batteries, light-emitting
polymers and roll-up computer
screens may sound like fantasy, but
they could be in the shops in the
near future.
http://www.apme.org
5
protecting our world for future
Everyone is increasingly aware that we need to act more
responsibly to protect our world for future generations.
Many industries and governments
explain their commitment as “acting
in a way which does not limit the
range of environmental, social and
economic choices available to our
grandchildren”. This mission is known
as ‘sustainable development’.
Everyone has a key role to play.
Plastics and the plastics industry play
their part in contributing to
sustainable development in the
following ways:
➔ Environmental protection:
constantly seeking ways to help
save resources such as oil, other
fossil fuels, water and even food.
The industry aims to do more
with less.
➔ Economic development: the plastics
industry adds value to society
through the employment and the
wealth it creates – over one million
workers in Europe.
➔ Social progress: plastics play a
crucial role in innovative
technologies and products that
provide higher standards of living,
healthcare and education for an
ever-growing world population.
This card explores how plastics can
contribute to environmental
protection to help us all achieve the
ambition of a more sustainable
lifestyle. You may want to look at
cards 4, 6 and 7 to help with some of
the activities.
Doing more
with less
The environmental group Greenpeace
often asks the question “why are we
using these materials in the first place
ACTIVITY 1
1 Describe three examples of efforts people are making now to live
more sustainable lives than, say, in the 60s and 70s, e.g. using less
energy than before, or using resources more efficiently. What benefits do
these efforts bring?
and are they necessary?” This is a
good starting point.
All products are made from raw
materials. Most plastics are produced
from crude oil, which is a limited and
valuable resource. However, very little
of total oil production is used for this
purpose – only 4 per cent for all
plastics products. Although the
production and use of plastics have
grown steadily, the amount of oil used
has grown less quickly. This is because
continuing innovation means plastics
are lighter, yet stronger and more
adaptable.
Assessing environmental
impact
Everything we use, whether made of
wood, glass, plastics, paper or metal,
has an impact on the environment.
This includes finding raw materials,
making and using products and
disposing of them at end-of-life.
All other 5%
Plastics 4%
Transport
45%
Other petrochemicals 4%
This opens up a huge range of uses
for plastics yet at the same time
means that, product for product,
proportionally less of the world’s oil
and energy resources are being used,
with lower overall impact on the
environment.
Heating,
electrical &
energy
42%
inputs
raw materials
acquisition
outputs
energy
manufacturing,
processing and
formulation
water
effluents
distribution and
transportation
airborne
emissions
packaging options and is lighter to
transport meaning less fuel is
consumed and fewer emissions
produced. However, at end-of-life,
plastics film is often contaminated
and difficult to separate from the
household waste making it difficult
to recycle mechanically. Using life
cycle analysis it is possible to
determine the overall environmental
impact of a product, from production
to disposal.
Savings throughout the
life cycle
use/re-use/
maintenance
solid wastes
recycling
products
waste management
power
and heat
raw
materials
Environmental impacts include
contribution to global warming,
depletion of finite natural resources
and waste. Without taking all of these
factors into account, through proper
studies, it is impossible to make sound
environmental decisions. Such studies
involve looking at each part of the ‘life
cycle’ of a product, as shown above.
While the European waste
management industry is working hard
to meet the challenges of the
recovery targets set by the EU (see
card 6), it is important to keep in
mind the ultimate goal – the efficient
use of resources to meet the needs of
future generations. In some instances,
new plastics products and
technologies, that reduce the amount
of raw materials used and the impact
during use, may make it more
difficult, and therefore less
economically or environmentally
beneficial, to collect and sort the
plastics at end-of-life.
For example, lightweight film uses
less raw materials than traditional
Reducing the amount of raw
material used in the first place
New polymers and new technologies
have greatly reduced the amount of
raw materials needed to pack a
product. For example, by printing
information directly onto the plastics
wrapper of its bread, one supermarket
has reduced the need for extra labels
and packaging materials by 23 per
cent per package.
Using less fuel, creating fewer
emissions during use
Reducing the amount of material used
in a product has a direct impact on
the weight of loads. For example,
reducing the amount of packaging for
ACTIVITY 2
1 Think of a plastics item you might find in your home or classroom. Using
the flow diagram as a frame, consider the environmental impact of this item
throughout its life cycle.
Use these ideas to draw your own flow diagram. Begin by making a rough
sketch and then compare notes with others in your group. Then see if there
are any points you want to add to your sketch before making your final
diagram. You might find it helpful to add artwork of some kind.
Make sure it is clearly labelled with the following key words:
➔ raw materials
➔ energy
➔ manufacture
➔ product distribution
➔ consumer use
➔ re-use
➔ disposal
➔ combustion with energy recovery
➔ recycling
➔ chemical treatment
➔ landfill
➔ they need less raw materials and
ACTIVITY 3
use less energy to manufacture.
➔ Their low mass means less energy
is needed to pull them, there is less
wear on the machinery, the wheels
and the rails and the plastics
material will not rust.
1 Find an example of an
object that can be made from
less raw material today than
in the past. Does the object
function better, worse or the
same?
Do you think there are
energy savings from using
less raw materials to make
it? What are they?
a product – whether large or small –
means you transport more product
and less package each time you fill a
truck or load a train. This reduces
emissions, fuel usage and costs.
Granular detergents are now being
sold in plastics pouches which use 90
per cent less packaging than
equivalent containers.
Improvements in design and
technology used in cars have
dramatically reduced fuel
consumption. Between 1974 and
1988, fuel consumption dropped by
an average of 14 per cent for 18 car
models in Europe. Plastics contributed
to at least half the saving through
lighter weight and improved
aerodynamics because of their
mouldability.
Minimising impact and maximising
recovery at end of life
Often we look at waste when we
think about saving resources. But an
important question should be asked
before we think about waste and
whether it should be recycled or
thrown away. Can we prevent it from
becoming waste in the first place?
Either by reducing the amount of
material used to make it or extending
its life by re-using the product.
For example, a large chain of
supermarkets encouraged customers
to bring the company’s plastics bags
back to their stores and use them
again. The incentive was a small
refund for every bag reused. As a result, they
reduced their use of
new bags by 60
million in one year
and saved 1000
tonnes of plastics.
Looking further into the future, it
is predicted that ultra light-weight
vehicles will be made from plastics,
including parts of the engine,
transmission and axles. This could
mean a 500kg car with greatly
increased fuel efficiency that weighs
less than its passengers and luggage
while retaining its safety features.
Sustainable development
1 Look at the different
means of transport which
students in your class use
to travel to school. List
some parts of those vehicles
which are made of plastics,
e.g. car seat, bicycle
mudguard. For each one,
what alternative material
could be used, e.g. leather,
metal. Can you describe any
advantages or disadvantages
of using plastics in terms of
function, environmental
impact or cost?
and how we can make
a contribution in our
day-to-day lives
Making transport work harder
Different modes of transport have
different environmental
consequences. For instance, if
everyone travelled to school by bus,
rather than in individual cars, there
would be less fuel used and fewer
emissions. This may not always be a
practical solution but we should all be
encouraging such systems.
Plastics have made a great
contribution to energy efficiency in
transport because they are light and
reduce the weight of vehicles. This
can be achieved by a simple design
solution i.e. choosing plastics instead
of a heavier material, and by
technological advances.
For example plastics have made
possible the largest one-piece
component in the world – a railway
carriage. This is manufactured in
Switzerland and has four major
benefits:
➔ the carriages are quicker to make;
➔ they are 25 per cent lighter than
traditional carriages;
ACTIVITY 4
Creating sustainable buildings
There are many examples of building
materials and fittings where plastics
materials are replacing traditional
ones because of their benefits of
strength, durability, lightness,
insulation, low cost, low
environmental impact, non-corrosion
and aesthetic appeal. These include
window frames, pipes and insulation.
Plastics contribute to sustainable
buildings in a number of ways:
➔ Energy efficiency: is a key concern
in modern buildings, and plastics
can provide huge benefits. In
northern European countries,
almost one quarter of total energy
consumption is used for domestic
heating. Plastics’ insulating
properties means that this can and
is being reduced considerably.
Research shows that 50kg of
plastics foam used to insulate a
house saves 3,700 litres of heating
fuel over 25 years – equivalent to
150 litres a year. It is estimated
that since the energy crisis of the
1970s, the use of such foam in
construction has saved the
equivalent of more than five billion
gallons of oil.
ACTIVITY 5
1 What do you think is meant by an ‘intelligent polymer’? Describe an
imaginary intelligent polymer and what uses it would have.
What functional and
environmental benefit might
there be to ‘system-built
housing’ compared with
conventional building methods?
Think of the features of a
housing construction site, e.g.
bricks, wooden beams, window
frames, glass.
➔ Emergency housing: today, more
people live in cities than the total
number of humans alive 100 years
ago. At the same time, with the
world’s population growing faster
than at any time in history, the
provision of shelter is becoming
even more critical. Advances in
plastics engineering and design are
allowing the development of lowcost ‘system-built housing’ that can
be constructed simply and quickly
in any climate and can even meet
the demands of earthquake zones.
➔ Space exploration is providing the
inspiration for some of these
developments. For example, one of
the concepts considered for living
quarters on the International Space
Station is a lightweight, inflatable
habitation module. Based on the
design of a space suit, the module is
a multi-layer, puncture-resistant
construction to house four to six
astronauts.
➔ Environmental impact: in southern
Europe, more and more homes are
being fitted with solar heating
systems which turn the sun’s
energy into heat. Plastics are a
vital component of the solar heating
equipment.
As well as helping to warm
buildings, plastics can also help
keep them cool. Two ‘intelligent’
polymers are now being developed
to provide shade and prevent
overheating in buildings. The
materials are transparent at room
temperature but become milky
when exposed to bright sunlight.
They reflect the light and prevent
the building overheating. They will
provide alternatives to blinds and
the need for air conditioning.
http://www.apme.org
6
dealing with
Despite reduction and re-use, there will always be waste to deal with,
whatever materials we use.
As the demand for plastics grows, the
challenge is to find ways to ensure
maximum recovery to avoid the loss
of a valuable resource at the end of a
plastics product’s or package’s useful
life. The best way to do this is to use
all the available recovery techniques
to optimise the balance between
environmental gain and cost. There
are three main options to manage
plastics waste:
Recycling
The process of mechanical recycling is
encouraged where it makes
environmental and economic sense.
For example, this is often the case
when large amounts of the same type
of plastics waste can be easily collected,
such as distribution and agricultural
films, car battery cases, soft drinks
bottles and other containers.
The five stages in the recycling of
plastics are:
1 disposal by the user
2 collection by a local authority or
company
3 sorting into single types of
plastics
4 cleaning to remove labels, dirt
and content residues
5 re-processing into granules or
flakes which can then be formed
into new products
Throughout the European Union,
material recycling targets have been
set for some sectors and opportunities
to increase plastics recycling are being
explored. For packaging, for example,
research forecasts that there is the
potential to increase the amount of
mechanically recycled packaging
plastics to a European average of 15
per cent in 2006, compared to 11 per
cent in 1995. There are also
opportunities for increases in areas
such as agriculture, automotive and
product distribution. However, there
are barriers where the waste is hard to
collect or where different components
in integrated, complex products, must
be separated (for example computers
and electronic equipment).
Different thermoplastics do not
mix well when heated together and
the strength of the recyclate is
reduced. While mixed plastics can be
recycled into products such as fence
posts it is much better to recycle the
same type of plastics together.
High calorific
alternative fuel
When separated from
other waste, the high
energy content of
plastics make them an
excellent substitute for
fossil fuels in energyintensive processes, for
example in cement
production.
Municiple
Solid Waste
(MSW)
Mechanical
recycling
Material reprocessing
of waste plastics by
physical means into
plastics products.
Energy
recovery
Plastics are made from oil –
this gives them a calorific
value equal to or greater
than coal. This energy
value can be recovered
via combustion.
Material
recycling
Recovery
Options
Reprocessing in a production
process of waste plastics for
the original purpose or for
other purposes excluding
direct energy recovery.
The incineration of
plastics waste along
with other materials in
MSW can safely and
cleanly generate heat
and/or power.
Landfill – A disposal route for residues not recoverable
Feedstock
recycling
Material reprocessing of
waste plastics by
chemical means into
basic chemicals,
monomers for plastics
or hydrocarbon
feedstock.
ACTIVITY 1
It is important to try to separate different plastics early in the recycling process.
1 Why is waste separated into different plastics always likely to be more
valuable and more useful than waste which remains mixed?
2 Why are dark plastics separated from clear plastics - even though they are
made from the same material?
3 Have a look at home at the plastics packaging materials in the kitchen or
bathroom. Look for the code number stamped on the bottom or inside of a
container. Make a table showing which plastics are used for which purposes.
4 Make a careful note of where two different plastics are used in the same
electrostatic separation. This
can be used with plastics that
take different electrical charges – for
example, PET and PVC
selective dissolution. Organic
solvents are used to dissolve
one or more polymer types that can
then be filtered, isolated and
re-solidified
ACTIVITY 2
item e.g. for a lid and a container. Why are different types selected?
The common plastics have been given
a code number which you will find on
much of today’s packaging. This
coding system can now be used to
help identify plastics when separated
by hand. In several European
countries, including Germany and
France, a labelling system called the
‘green dot’ is used to indicate that
money has been paid to national
recycling systems.
To further help in recycling endof-life products, manufacturers are
being encouraged to take recycling
into account at the design stage. This
could, for instance, involve making a
label more easily removeable from a
package by using water-soluble glue.
Recycled plastics are often used in
completely different applications. For
example, fizzy drinks bottles are mainly
recycled into fibres.
Apart from hand-sorting, three
other methods for separation are used:
analysis of the elements in
the plastic. PVC is easy to
spot because of the chlorine atom in
the molecule. Automatic systems exist,
for example to identify and sort
different types of plastics bottles
separation by density. The
plastics are cut into
flakes and mixed with a liquid so
that some float and some sink,
or can be spun in centrifuges
1 The density of
polypropene is 0.91 g/cm3.
The density of polystyrene is
1.05 g/cm3. What density
would a liquid need to be to
make sure that the
polypropene floated and the
polystyrene sank?
2 PET has a density of
1.35 g/cm3. What density
would a liquid need to be if it
was to separate PET from
polystyrene?
3 Ease of separation of
plastics materials is now
being taken into account at
the design stage. What
recommendations about
design rules would you make?
Think about densities, colour,
inks and labels.
4 Recycling makes a lot of
sense, but only if demand for
recycled materials matches
the supply. If demand is much
less than the supply, what
will happen to…
➔ the price paid for the
recycled material
PET (polyethylene
terephthalate)
HDPE (high density
polyethylene)
➔ the amount of recycled
material in storage
➔ the costs of the process
➔ the profitability of the
process?
LDPE (low density
polyethylene)
V (vinyl)*
PP (polypropylene)
*PVC
PS (polystyrene)
Other (including
multi-layer)
5 If there is a large
difference between supply
and demand, the amount of
waste being collected will
have to be reduced. What
effect might this have on
public opinion and on the
wisdom of recycling?
cycling
Feedstock re
ACTIVITY 3
The potential of new recycling
technologies such as feedstock
recycling is being investigated by the
plastics industry.
Feedstock recycling, which is
mainly used for mixed plastics waste
is currently only practised in Germany
but possible investment in other
countries is being considered. There is
still much to be learnt about the
potential for these technologies if
they are to offer the opportunity to
increase recycling in the future.
1 Summarize these processes in a flow diagram. Make sure that you
distinguish between the different stages, and between the usefulness of the
four end-products.
2 What other factors do we need to take into account before we can know
whether processes such as these are actually of benefit? Think of the costs
involved.
Energy from
waste
Re-use and recycling are not the only
waste management options. Plastics
waste has a high calorific value,
equivalent to coal or oil, which can be
safely and cleanly released through
combustion to generate heat and/or
power.
There are three main types of
plants to recover energy from plastics
waste: combustion with household
waste in a municipal incinerator or the
combustion of plastics as a fuel, usually
in combination with traditional fossil
fuels in a manufacturing process or a
power generation plant. Pre-sorted
mixed plastics packaging waste for
example, has been used effectively as a
substitute for coal in energy-intensive
processes such as cement manufacture.
In mixed waste incineration, the 8%
plastics content produces 30% of the
heat energy released.
One concern often associated
with combustion is the level of dioxin
emissions. A very small number of
these are toxic although their degree
Collection and sorting
Treatment of the plastics waste
e.g. grinding
Feedstock recycling into basic raw
materials
Closed-loop recycling back to the
original plastics or as feedstock for
new petrochemical products
There are four main methods of
feedstock recycling:
Pyrolysis
Plastics waste is heated in a
vacuum producing a mixture of
gaseous and liquid hydrocarbons
not unlike petroleum.
Hydrogenation
Plastics waste is heated with
hydrogen. This ‘cracks’ the
polymers into a liquid hydrocarbon.
Gasification
Plastics waste is heated in air
producing a mixture of carbon
monoxide and hydrogen gases.
This is used to produce new raw
materials such as methanol.
Chemolysis
Certain plastics can be chemically
treated and turned back into the
raw materials for making the same
plastics.
kcal
15000
12500
This diagram shows the heat energy
content of 1kg of lignite, diesel oil and
plastics.
10000
7500
5000
of toxicity varies greatly.
Dioxins are formed where carbon,
oxygen, hydrogen, chlorine and heat
are present and they are an unwanted
by-product in a variety of combustion
and manufacturing processes. They
can also occur in nature in forest
fires, volcanoes and compost heaps.
Dioxin emissions from waste
combustion have been closely
monitored and much research
undertaken to reduce such emissions
to meet the most stringent safety
requirements. Well operated
incinerators in fact destroy dioxins.
European legislation means that by
2005 all municipal and clinical waste
combustion will contribute just 11g
per year (or 0.3%) to overall dioxin
emissions.
Already across Europe over
2.6 million tonnes of plastics waste is
burnt each year replacing fossil fuels
to produce useful heat and/or power.
This takes place in well-managed
incineration plants or cement works
where emissions are carefully
monitored and limited.
There is an obvious need in
recycling to balance supply and
demand. There is no point in
collecting material for recycling if the
recycled material cannot be produced
and marketed in an environmentally
and economically acceptable way.
There is also a need to consider other
ways of treating waste.
What should we do?
➔ Recycle plastics as materials?
➔ Recycle them as feedstock
2500
chemicals?
➔ Release the energy they contain
1kg lignite 1kg diesel oil
1kg plastics
through combustion?
ACTIVITY 4
1/1 Look at the following information & produce a poster which summarises it.
2.6 tonnes of domestic waste has the energy value of 1 tonne of coal.
A 10% increase in the amount of waste combusted would save over
1 million tonnes of coal.
Sweden already recovers energy from 33% of its plastics in domestic
waste, providing a significant proportion of its total district heating
needs. In Denmark, 56% of plastics in domestic waste is recovered for
energy. In Switzerland the figure is 55%.
If European waste was incinerated and the heat energy recovered, it could
provide 5% of our domestic electricity needs and halve coal imports.
2 This table shows what happens to plastics waste across Europe
1994
1995
total plastics waste
17505
mechanically recycled
1057
feedstock recycled
51
energy recovered
2348
total plastics recovered
% waste recovered
20%
1222
99
2698
4019
25%
Amounts (’000 tonnes)
1996
1997
16871
17454
1440
334
2575
4349
251
2496
4067
24%
Complete the table by calculating the data missing from the empty boxes.
The answer is probably to do all three,
and to decide on the best combination
of options. The option chosen depends
on the specific circumstances. For
example: What sector is the waste
from? How is it collected? What
sorting, separation technology is
available? Is there a demand for
recyclate, feedstock or alternative
fuel? Studies can be done which assess
the environmental impact of the
recovery or disposal option chosen. In
fact, such studies can be carried out
over the whole life-cycle of the
plastics product and this sort of
analysis can help with choosing the
best material at the design stage.
y
Degradabilit
Degradable plastics have been
produced which can be broken down
either by light or bacteria, but they
are not yet widely used. Such plastics,
however, are not an easy solution to
waste management because they can
take many years to degrade
completely and can represent the loss
of a valuable resource that could be
otherwise recovered for a second life.
However, they do have certain
applications in medicine (e.g.
degradable stitches and other bioproducts) and agriculture (e.g. film for
improving the growth of crops).
Landfill
In parts of Europe where waste cannot
be burnt to release energy, it is still
disposed of in landfill sites. Landfill is a
waste of resources. The plastics industry
is committed to optimising the
combination of recovery options to
divert as much waste as possible from
landfill.
In the past, landfill sites have often
been located in disused quarries or clay
pits. Filling these large holes in the
ground with solid waste has been a
good way of removing landscape eyesores and restoring land.
Landfill sites contain organic
material – usually more than 50 per
cent of the total mass of waste.
Because of this they behave like
gigantic compost heaps with paper,
food and natural fibres slowly breaking
down through bacterial activity.
Modern sites can contain many millions
of tonnes of material, with thousands
of tonnes being added each day.
Landfill sites create two byproducts – a liquid and a gas. The
liquid is rather like concentrated
sewage and must be contained within
the site to avoid its seeping into the
water supply. To prevent this, the site
is usually lined with clay or plastics.
The gas is a mixture of carbon dioxide
and methane (which can be explosive
if not properly controlled) and both
contribute to global warming. There
are a number of sites where this gas is
now collected and used for the
generation of electricity or heat.
Today, it is recognised that landfill
is not a viable long-term waste
management option. To encourage
manufacturers to design products that
maximise the use of resources
throughout the life-cycle and to make
recovery options more attractive, the
financial cost of landfill is being
increased.
This card has shown something of
the three main options for dealing
with plastics.
➔ Recycling
➔ Combustion with energy recovery
➔ Disposal
All of these are used to varying
degrees across Europe today. There are
changes from time to time as to which
process is the most attractive. For
example, changing oil prices on the
world market can affect the value of
recovered plastics materials and hence
the incentive to recycle.
ACTIVITY 5
1/1 Draw up a table of
advantages and
disadvantages of
➔ recycling of waste
➔ energy recovery from
waste through burning
Think of transport costs,
emissions, effect on other
resources, land use.
Legislation now strictly
controls the design and
operation of landfill areas.
http://www.apme.org
7
dealing with
Individuals, communities, corporations – we all contribute to the large
amounts of waste that need to be taken care of.
On average each of us throws out
these items each year:
110
glass
bottles
290
metal
cans
130
newspapers or
magazines
66
plastic
bottles
70kg
of vegetable waste
and food scraps
As discussed in card 4, plastics are
often used for packaging because
they are resilient, light, clean and cost
effective. Therefore, household waste
contains plastics as well as other
materials. In card 6 we looked at some
of the ways in which we can deal
with plastics waste.
Increasingly, efforts are being
made to manage this waste in order
to reduce its impact on the
environment and maximise the
amount of waste given a second life.
Once collected, waste can be reused, recycled or recovered as
energy. As a last resort it should
be buried in landfill sites for
safe disposal. However,
when we throw things
away irresponsibly they
have no chance of
entering a sensible waste
management and
recovery system and
instead, they become
litter.
Litter typically consists of
packaging items thrown away
without regard to the surroundings.
It ends up in public spaces causing
serious social, and environmental
consequences, as well as being a
waste of resources.
In an ideal world, litter would not
exist because people would behave
with care for their environment.
One of the most important steps
towards solving the litter problem is
making sure that everyone knows
that it is people who create litter,
and not the companies which make
the products.
litter
Identifying
Sadly, wherever you are you
will find litter – in city
centres, the countryside,
on the coast and at sea.
Although it’s hard to
believe, even Mount
Everest in the
Himalayas has a litter
problem!
A survey of European cities found
that the top five items of litter were
cigarette butts and matchsticks,
pieces of paper, sweet wrappers and
bits of plastics.
To find out whether our attitude
towards littering is improving or
getting worse, litter in the
environment is measured.
ACTIVITY 1
As a class, identify at least ten different 50-metre strips of land near your
school or where you live. Identify, list and classify all the items of litter.
For example bottles, bags, cigarette butts.
▲ Which items are most commonly found?
▲ Which could be dangerous to people or wildlife? Explain why.
▲ Which would be difficult or costly to remove?
▲ Which could be recycled or used again?
▲ Using the Litter Index below, what grade A-D would you give to the area
that you surveyed?
Based on the Tidy Britain Litter Index, towns and cities can be assessed as a
whole. If ten sites were surveyed and each scored A (or 5), then the town
would score 50/50 or 100%, but if each site scored only D (or 1) then its
cleanliness index would be 10/50 or 20%.
Use the grades that the class calculated for the ten sites to calculate an
overall cleanliness index for your neighbourhood.
One way of measuring litter is with a
litter index such as the one below.
Using a five-point scale, litter found on
a 50-metre length of road, footpath,
beach or parkland is measured.
Grade A Rating 5/5
Completely free of all
items of litter
Although you are probably more
aware of the litter in your local area
than elsewhere, when you visit other
places you cannot escape the litter
problem. In fact, litter in holiday
spots and at sea attracts the most
attention. Is this because we expect
to enjoy the seaside or natural
scenery where we choose to spend
our holidays and forget that our
actions create the same impact
wherever we are?
Grade A- Rating 4/5
Appears free of litter but on
careful inspection has 5 or less
small items of litter
Coastwatch Europe collects data
about coastal litter and pollution.
A recent survey of some 10,000 sites
found over 60 items of packaging
litter at each location. These included
cans, cartons, bags and bottles as well
as cigarette butts, matches and
newspapers. Pollutants – including
sewage, oil and tar – were also seen.
Causes and consequences
of litter
Nearly all of us can remember an
incident when our behaviour created
litter. The way we act in different
environments determines the type of
litter produced and where it is
found.
For example, litter found on
beaches comes from a number of
sources. Holiday-makers picnicking
on the beach bring a large number of
disposable items such newspapers,
packaged food and drinks and
cigarettes. When these items are
taken home after use or put in a bin,
no litter is created, but
frequently people don’t
dispose of them
responsibly. Sometimes
this is because
there are not
enough
bins, but
often it is
just carelessness.
Grade B Rating 3/5
Small items of litter present,
like bits of paper and milk
bottle tops
(source: Tidy Britain Group)
Grade C Rating 2/5
Clearly noticeable build-up of
litter: cigarette butts, paper,
cans and packets
Grade D Rating 1/5
Lots of clearly visible litter
and large items like
household goods
But not all coastal litter is created
by irresponsible individuals at the
location in question. Even
uninhabited islands are littered with
materials washed ashore by ocean
currents that do not recognise
national boundaries. This litter can
come from other beaches or by the
casual but illegal dumping at sea of
items including food packaging and
bottles.
While some litter will rot over
time, much of it remains unless it is
collected and removed. Apart from
the fact that it is unpleasant to
look at and spoils our environment,
it can also:
injure people
For example, rusting
cans and broken glass
can lie hidden in the
sand or in the grass
and cause nasty
injuries when people
tread on them.
be a health hazard
What can be done to
m of litter?
solve the proble
kill or injure wildlife
For example, a harmless plastic bag
disposed of carelessly could look like
an edible jellyfish to a sea turtle, but if
eaten it may kill. Damaged fishing nets
cut loose by fishermen can be a death
trap for dolphins who become
entangled and drown.
cost money to clean up
For example, according to the Local
Government Financial Statistics
Unit of the Department of
Environment, Transport and
the Regions, street cleaning
in England and Wales costs
local authorities almost
£340 million a year.
Insects, rats and mice
frequently congregate
around discarded food
wrappers and
sanitary products,
potentially leading
to the spread of
disease.
ACTIVITY 2
Think about the type of waste found in different places:
rural, urban and coastal.
▲
▲
▲
Who is responsible for the litter in each environment?
▲
Identify what litter might be biodegradable, do you think biodegradability
is the answer to protect our environment or would it encourage people to
litter more?
Do you think the amount of litter has increased in recent years?
Consider each environment in turn, what measures could be taken to
reduce litter?
▲
Consider the consequences of the types of litter found
in each environment.
Everyone is responsible for the
problem. If anyone breaks the litter or
waste disposal laws then local
authorities can take action. This
happens all over Europe. Local
authorities also encourage individuals
to take pride in their area, provide
disposal facilities and organise litter
collection. Clearly, it is much cheaper
to manage waste disposed of
responsibly, than to collect it as litter
from the streets, countryside and sea.
ACTIVITY 3
Find out what schemes operate
in your country, who is involved
and how they work.
Throughout Europe, campaigns have
been run to raise people’s awareness of
litter. In the UK, the Tidy Britain Group,
which uses programmes of action and
education to fight litter and
littering, is the recognised
national agency. On a
more local scale, schemes
range from the
annual enlisting of
volunteers from
schools, sports
clubs and local
organisations
to help clear
litter on a
particular
day, to more formal partnerships. For
example, in Devon, the Tamar Estuaries
Management Plan brings together
local municipal and harbour
authorities, water companies and
residents. They work together to ensure
that adequate facilities for litter
disposal are in place, collection services
arranged and that the public is kept
informed.
do
an you
What c
to help?
Can you say that you have never added
to the problem? When did you last drop
a sweet or crisp wrapper, a piece of
chewing gum or drinks can somewhere
other than in a waste bin?
ACTIVITY 4
As a class, discuss the litter problems in your local area.
Think about the causes and the consequences. Choose ONE
aspect of the litter problem and draw up a plan to tackle it.
For example, this could be organising a litter
awareness campaign in your school, or getting the
local authorities to place more bins in a specific
location.
Make sure your plan answers these points:
▲
Who would you need
to involve?
▲
How could the plan
be carried out?
▲
Which organisations/
authorities would be
able to help or
advise?
▲
How would you tell
people about it and
get them to take
part?
▲
Which organisations
would you need to
consult?
▲
How would you check
its progress?
▲
How and when would
you measure its
success or failure?
Now you have learnt a bit more
about the consequences of your
actions, would you stop and think
before contributing to the litter
problem?
While it is important that cleaning
up litter is organised, it is only part of
a solution. We all have a role to play
so that one day litter will no longer
be a problem.
http://www.apme.org
22008 UK Water AW
04-03-2003
10:21
8
Pagina 2
for life
We live on a blue planet, where two-thirds of the surface is covered with
water, but most of the water on Earth is too salty to be useful for
anything but sailing on.
blem
A pro
to solve
But we need more water now. The
UN has declared water a human right,
which means that everyone should
have access to sufficient, affordable,
Only 3.5 per cent of the planet’s total
accessible and safe water supplies and
surface water is fresh, and most of that
sanitation services. Unfortunately, one
is frozen in the ice caps. A mere 0.01
billion people live without access to
per cent – one drop in every bucketful
adequate drinking water, and over two
– is in a form suitable for direct human
billion people lack basic sanitation.
use: in streams, rivers, lakes and
Every day, 10,000 children die from
groundwater aquifers.
cholera
and other waterborne diseases.
Between 1950 and 1990, global
Eighty per cent of all diseases and onewater demand tripled – and it is still
third of all deaths in developing nations
rising. If current trends persist, the
are caused by contaminated water.
demand for water could exceed the
Bilharzia, typhoid, salmonella, E coli,
available supply within 30 years. There
hepatitis, parasitic worms – all these
simply won’t be enough falling from
are potential killers. They can be found
the sky to satisfy our needs.
in the rivers and streams that many of
the world’s poor depend on for their
water supplies.
There are many needs that
3.5%
must be met by clean water.
Farmers need water for their crops.
Families need water for cooking and
washing. In parts of Africa, women and
children may spend three hours a day
walking to a water source, then
queuing for a chance to fill a pot.
Water is also a problem in Europe.
In an average year, over 3000 cubic
metres of water are available for every
European Union inhabitant. Around 20
per cent of the available water is
actually used, but there are still
shortages in some areas. For example,
in southern European countries,
periodic droughts are a major
environmental, social and economic
problem. In other countries, ageing
water supply systems lead to cracked
pipes and subsequent water leakage.
ACTIVITY 1
1 How much water do you
think you use on average per
day? Think about what purposes
you use water for and list some
ways in which you could be
more efficient in your use of
water.
2 Identify three European
countries that you think would
be likely to suffer water
shortages in summer.
3 Can you discover the name
of one European country that
uses desalinated sea water for
nearly half its drinking water?
The problem of water shortages
looks set to get worse due to the
impact of climate change. Most
scientists agree that global
temperatures will rise by the end of the
century by between 1.4°C and 5.8°C.
There are likely to be more floods and
storms but also more droughts and
heat waves, affecting crop yields, water
supplies and health.
We have to learn to use the water
we have more carefully, in a more
efficient way. The world is becoming
increasingly aware of the need to act
more responsibly to extend our help to
those in need and at the same time, to
protect our world for future
generations; what is now known as
“sustainable development”. This is a
term used to describe acting in a way
that does not limit the economic, social
22008 UK Water AW
04-03-2003
10:21
Pagina 3
and environment options available to
us now and in the future. Efforts to
promote sustainable development
received a boost at the World Summit
on Sustainable Development held in
Johannesburg, South Africa, in 2002,
where world leaders met to discuss the
protection of the environment and how
to tackle the causes of poverty
throughout the planet. Scarcity and
misuse of fresh water were highlighted
as two of the most serious threats to
sustainable development. As a result of
the Summit, all heads of governments
agreed to aim to halve the number of
people without access to clean water or
proper sanitation by 2015.
Water can be ‘delivered’ to
consumers in different ways. Whatever
the solution, the aim is to make
available adequate quantities of water
safe for human consumption.
Plastics play a vital role in
preserving and distributing water
economically and reliably to a growing
world population. In many areas of the
world where water is scarce,
conservation and irrigation systems
help retain water and distribute it –
either for domestic or industrial use,
or for growing crops. Plastics are a
favoured material in many of these
applications due to their costeffectiveness, ease of transport and
assembly, flexibility and durability.
‘All people, whatever their stage of
development and social and
economic condition, have the right to
have access to drinking water in
quantities and of a quality equal to
their basic needs.’
WaterAid was able to help
7 million people gain access
to clean water in the
developing world, thanks, in
part, to plastic piping.
r for life
Wate
Preserving and distributing
clean water
In much of the world, polluted water,
improper waste disposal, and poor
water management cause serious public
health problems. Such water-related
diseases as malaria, cholera, typhoid,
and schistosomiasis harm or kill millions
of people every year. In an ideal world,
the solution would be to prevent the
water supplies becoming polluted in
the first place. But sewage treatment to
clean the water source is expensive and
even European rivers aren’t drinking
water quality… yet!
There are other ways of accessing
clean water. In remote mountain areas,
such as Nepal, there is often plenty of
water. But poor hygiene and a lack of
sanitation may leave the village stream
or river badly polluted. One solution is
to pipe in clean water from further
upstream, relying on gravity flow.
Plastic piping is ideal for this situation.
It is light, flexible, easy to carry, yet
strong once it is in place.
In lowland areas, the problems are
often more difficult. There are more
people competing for the same water,
which is often dirty and unsafe. One
answer is to drill down to the waterbearing aquifer below the surface.
Using hand pumps and plastics pipes, a
village can often find clean water, but
the drilling operation can be expensive
and, if too much water is extracted, the
aquifer itself can become contaminated.
Plastics also help purify water and
remove disease-causing bacteria and
parasites. A simple nylon filter has
almost eradicated Guinea Worm
Disease which cripples victims, leaving
them unable to work, attend school,
care for children or harvest crops.
The worm enters through the
digestive system, but then makes its
way to anywhere in the body, boring
close to the skin surface. When an
infected person steps into water, the
worm releases millions of larvae. People
who drink the water become infected –
and the cycle starts all over again.
The answer is to filter the parasites
out of the water. In the past, this has
been done with muslin cloth, but the
special nylon monofilament cloth is
easier to disinfect and cheaper to
supply. Filtering has successfully
reduced the cases of infection by
95 per cent.
Source: UN Conference at Mar del Plata, 1977
ACTIVITY 2
Use of abstracted water
(ie taken from rivers,
reservoirs, canals etc) in
Europe:
18% – public water supply
30% – agriculture (mainly
irrigation)
14% – industry, excluding
cooling water
38% – power (hydropower,
cooling water) and nondefined uses
1 Where would it be best to source water for piping? Further upstream?
From a deep water pool? From a spring above the village? Explain why.
2 Contaminated water may contain bacteria, viruses and parasites. For
each type of contamination, give an example and explain how someone
would be made ill by the micro-organism in the water.
3 The Guinea Worm is a parasite. Explain what a parasite is. Which of the
following are parasites and which are not?
house fly, fleas, rats, dandruff, tapeworm, salmonella
4 Would filtering water protect against bacteria and viruses? Explain why.
22008 UK Water AW
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Pagina 4
40 per cent or so of all irrigation water
gets to where it is needed.
One answer is drip-irrigation
(sometimes called trickle irrigation).
This works by applying water slowly
through plastic piping directly onto the
soil. Traditional sprinklers throw huge
amounts of water into the air and onto
plants, where much is lost to
evaporation. In contrast, microirrigation emitters apply water slowly,
close to the soil and roots of plants.
This is estimated to result in a 70 per
cent saving in water.
Drip irrigation is being used in
California, Israel, Spain and South
Africa – all places where water is
expensive and in short supply. In the
developing world, a cheaper solution
using buckets and surface pipes can
produce similar results.
In fact, pipes as old as 75 years have
been dug up – still in excellent condition.
Plastic sheeting can also be used to
reduce water losses from the soil. In
China, farmers are using plastics to line
the furrows in which rice is planted.
r for livin
g
Wate
Preventing water loss
through conservation and
irrigation
Water loss
In most countries, leakage in water
distribution networks is still too high.
Previously, where traditional
materials were used in the construction
of piping infrastructure, cracks and
leaks would occur in the piping systems
over time. In some European
countries, old pipes result
in losses of up to
30 per cent and
the cost of
leakage is
estimated at over
9 billion euros / year in clean water
wasted alone.
Although rarely seen, plastics pipes
under our streets and in our homes
play a critical role in delivering clean
water for drinking and other needs. In
Europe today, modern housing often
uses high-strength plastic piping to
deliver gas and water.
Plastics pipes have a long lifetime, are flexible and mouldable
which means that they are less
vulnerable to damage and easy to
manufacture and assemble. They are
extremely strong, which means they
can be used in the most demanding
of conditions, crucial to ensure that
they can distribute water in towns
and cities. Plastics are also light and
provide cost-effective solutions –
qualities that also make the material
ideal for widespread use, including in
the developing world.
Irrigation
Agriculture requires water, and rainfall
doesn’t always occur when farmers need
it. Add that to the fact that much
farming is in countries with low or
unreliable rainfall, making irrigation vital.
Irrigation systems exist to divert
water to crop, from a river, a dam or a
borehole. The first irrigation probably
took place on the River Nile thousands
of years ago, using a simple bucket and
lever mechanism called a shadouf.
Today, agriculture is the largest
consumer of water, worldwide.
Between 70 and 80 per cent of the
water withdrawn globally is used to
irrigate fields. Traditional methods of
irrigation are, however, enormously
wasteful. It is estimated that only
ACTIVITY 3
1 Plastics are flexible and
mouldable. Explain why this is
an advantage for pipes that
carry water. Give an example of
a material with poor elasticity.
2 Give an example of a
European crop that relies on
irrigation.
3 Evapotranspiration
describes water loss from the
ground and through vegetation.
How do plants and trees lose
water and at what point in the
year is loss through evapotranspiration likely to be highest?
4 Some farmers use strips of
plastic as a mulch – spread over
the surface of the soil around
the growing plants. Why do you
think this is?
5 Try to explain why so few
buildings are constructed with
water conservation in mind.
What would it take to change
this situation?
22008 UK Water AW
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Pagina 1
The sheeting lasts for five years and
prevents water waste in a desert area
between Mongolia and the Badain
Jaran desert. The plastic-lined furrows
also work to hold nutrients in the soil,
giving the farmers a double benefit.
Farmers have used plastic sheeting
to build temporary greenhouses for
years, but now the technology has
gone a step further with a purposebuilt controlled environment where
every plant has just the right amount
of light, water and food, and unwanted
flies and bugs are kept firmly outside.
Technology and plastics provide
solutions to water losses in agriculture.
ative
Innov
solutions
Solutions to the provision of clean
water continue to evolve and plastics
have their part to play.
For example, future developments
include a solar still which has been
designed by a company as a way of
producing pure water, using the simple
principles of evaporation and
condensation.
The pack is placed over a water
source – even floating on top of it if
required – and a wick allows water to
ACTIVITY 4
1 Try making your own
solar still. Dig a hole about
50 cms deep and a metre
wide. Place a plastic bowl in
the middle and cover the
whole thing with a thick
plastic sheet. Put a small
weight in the middle of the
sheet. Leave during a warm
day and cold night. See how
much water has collected in
the bowl the next morning.
2 Think about water use in
the modern home. How could
designers reduce family
water consumption? Make a
list of water conservation
measures – consider reducing
waste, recycling, rain water
capture.
One of the responses to the problem of poor water supply and
hygiene has been the growth of bottled water in recent years. This
presents a challenge in terms of packaging – how do you combine
safety, hygiene, convenience and ease of transport? Bottled drinks
are frequently packaged in plastics because they are:
lightweight yet strong (hence more energy
efficient to transport) and safer than glass
shatterproof
able to withstand high pressures without
shattering
pure and do not affect the taste of the
products they protect
recyclable
soak into the porous base. Sunlight
heats the inside of the plastic tent and
the water evaporates, leaving behind its
impurities as it does so.
On contact with the plastic walls,
the moist air condenses and pure water
runs down, to be collected in a channel.
The makers claim that the invention
could provide more than a litre of
water a day. But scientists are
considering farms of solar stills, capable
of producing enough water for a
family, or even a village.
Advanced plastics-based
technologies used in space exploration
could also be the key to improving the
distribution of fresh water supplies.
Plastics used in the life support systems
in space exploration help provide
astronauts with the cleanest air and
purest water possible, and better
sanitation than ever previously
experienced.
Only a thousand or so litres of water
are carried into orbit because of weight
and the amount of fuel that would be
consumed in order to take this water
into space. Space travel requires the
ability to reuse and recycle the existing
supply of water. As a result, highly
advanced personal water purification
systems have been developed for use by
astronauts, based largely on a plastics
filter system. These allow recovery of
85–95 per cent of the waste water and
urine. The water is then turned to steam,
and, following additional stages of
chemical, heat and mechanical
treatment, it is returned pure enough to
drink some 8–9 hours later.
This technology is now being
developed by organisations who hope
to make large scale water purification
systems for countries that need it.
Solutions to our water problems do
exist – the challenge is to make the
solution available to the people in
need. To date, plastics have helped
provide millions of people with access
to clean water, and will continue to
play a vital role in the future.
“Innovative materials such as
plastics have often provided
the solution to the problems
and challenges encountered
in space missions. Now the
same technologies are helping
to meet the challenges we
face on Earth”, says Pierre
Brisson, Head of ESA's
Technology Transfer
Programme
www.apme.org
Teachers’ notes
Card 1
1.1
Now
pencils
1.1
Before
wood
1.2
Reasons for using plastics
cheaper to manufacture
do not need sharpening
do not change length during use
development of ballpoint pens
rulers
wood
cheap
easier to read
easy to clean
can be transparent
car bumpers
chrome plated plastics do not rust and can be
steel
made so that they absorb impacts
without permanent damage
hi-fi cabinets
aluminium
more attractive design features
easier to mould into interesting
shapes
better acoustic properties
lenses on
car lights
glass
easier to make
safer when broken and lying on
the road
lemonade
bottles
glass
lighter and safer to carry
cheaper to transport
jumpers and
sweaters made
from acrylics
wool
cheaper to manufacture
easier to wash
2.2
Cost of fuel without use of plastics =
2000 x £0.70 = £1,400
4% saving = 4 x 1,400/100 = £56
4.1
The first plastics were developed in the 1860’s, but use grew only
slightly up to the mid- 1940’s when 2 million tonnes per year were
produced. By the late 1960’s this figure had doubled; production
then continued to grow at the rate of around 3 million tonnes per
year until the early 1970’s when production fell from 42 to 38
million tonnes. The same rapid growth resumed in the mid-1970’s
and continues now.
4.2
Economic growth during the 1950’s in the post-war period
stimulated the demand for new plastics.
4.3
The price of oil was doubled which forced prices up and cut the
demand for manufactured goods.
4.4
Graph should be extended at a rate of 3.5% per annum
Card 2
rayon, polyester silk
and ‘lycra’
clothing
low cost
easy care
better fit
cutlery handles
pottery/horn
materials more available
dishwasher-proof
buckets
iron
lighter
do not rust
less noise
2.1
Feature
Advantage
Safety
Plastics can absorb impacts and protecting
occupants; plastics are less likely to produce jagged
edges when bent or broken
Economy
Plastics have low densities and reduce the mass of
the car; this reduces fuel consumption
Style
Plastics can be manufactured in any shape,
producing cars with low wind resistance and good
fuel economy
Colour
Plastics can be coloured throughout rather than be
painted on; this reduces unsightly scarring from
stone chips and scratches
Cost
Plastics are easier to work with than metals reducing
manufacturing times and costs; plastics can be
cheaper than metals reducing raw material costs
1.1
1.2
1.3
A
CH2 = CH2
C2H4
28
B
CH4
CH4
16
C
CH2 = CH - CH2 - CH3
C4H8
56
D
CH3 - CH = CH - CH3
C4H8
56
E
CH2 = C - CH3
|
CH3
C4H8
56
F
CH2 = CH - CH = CH2
C4H6
54
C6H14
86
G
CH3
|
CH3 - CH - CH - CH3
|
CH3
1.4
The order of increasing boiling point (lowest to highest) is likely to
be: ABFCDEG.
3.3
C12H24O3N2
The mass of the molecule is one factor which influences boiling
point. The shape of the molecule is also important.
4.1
PET can withstand extremes of temperature and so can be used [a]
in the oven and [b] in the freezer without damage being done to
the plastic.
2.1
Ethene is a small molecule which contains a carbon-carbon double
bond. It is a flat ‘planar’ molecule which is very reactive because of
the double bond.
4.2
It prevents air and moisture passing through it.
Polyethylene is a long molecule with only carbon-carbon single
bonds. It is not planar and is very unreactive because there are no
double bonds.
2.2
CH2 = CH2 CH2 = CH2 CH2 = CH2 ➔
4.4
LDPE uses
• film wrap
• coatings for containers
and electrical cables
CH2 - CH2 - CH2 - CH2 - CH2 -CH2 -
HDPE uses
• toys
• petrol tanks in cars
• pipes
HDPE is used for products which need to be
reasonably rigid; the LDPE form for goods
which need to be flexible.
Card 3
3.1
C6H10O4
4.3
Low density polyethylene (LDPE) is more flexible than high density
polyethylene (HDPE) and therefore more useful in goods which
have to be bent, squeezed or twisted.
C6H16N2
3.2
NH2-CH2-CH2-CH2-CH2-CH2
-CH2- NH - CO - CH2 - CH2 - CH2 - CH2 - COOH
4.5
PVC
Wood
Aluminium
Weathers well and does not rot
Weathers over time and rots
Can weather over time
Does not require painting, meaning
lower maintenance costs.
No painting means less impact on
the environment*
Requires regular painting throughout life
Often painted to avoid damage through
weathering and achieve
customer colour preference
Recyclable at the end of life
Cannot usually be recycled/reused except
as fire wood
Recyclable at the end of life
Is flame retardant
Burns
Does not burn
Does not easily chip, dent or crack
Can be chipped, dented and cracked
Does not easily chip and dent
* producing and using paint has it’s own effect on the environment on top of the production of the window frames themselves
PVC is particularly successful at being precisely tailored, with added ingredients, to give long term weather resistance, toughness,
colour retention and durability to window frames. PVC has inherent flame retardant properties because of it’s chlorine content which
increases resistance to fire.
4.6
One possible investigation is to use cling wrap and other wrappings
such as plastic bags, paper bags, cellulose, and so on, to see how
effective it is at keeping biscuits dry.
The biscuits would need to be weighed beforehand, and then
weighed at regular intervals to see what increase in mass there has
been. Unwrapped biscuits can be used as a control.
Card 4
1.1
Plastics are used for the casings of electrical goods such as irons,
toasters, hair-driers, radios, hi-fis. They are also used for electrical
fittings such as plugs, sockets, switches, extension leads and
multi-plugs.
1.2
People can see if food is in good condition without handling it.
1.3
Plastics packaging acts as a barrier to micro-organisms keeping
medical equipment sterile. Plastics can be used safely for flexible
equipment such as tubes. Items which have to be disposed of after
use to ensure safety from contamination, for example syringes and
gloves, can be manufactured cheaply. Plastics can be moulded into
shapes which would otherwise require several components and be
more difficult to keep clean.
1.4
Small plastics items, if discarded as litter, could be ingested by
animals. Card 7 – Dealing with Litter, provides more information
about identifying litter, its causes and consequences and how we
can act more responsibly to minimise our environmental impact.
1.5
During use car parts become hot, but thanks to plastics’ inherent
characteristics, they retain their intended form and effectiveness.
Used for food packaging, certain plastics can be transferred
directly from the freezer to the oven or microwave.
1.6
Goods can arrive in the same condition in which they left the
factory; they are protected against the elements and against
accidental damage.
2.1
Poor distribution systems in many developing countries mean that
food takes a long time to reach the consumer from the farmer and
so a lot of it goes off. Lack of refrigeration facilities means foods
deteriorate more quickly. Food wastage can be as high as 70%
compared to 1-2% in western Europe using packaging.
2.2
Packaging keeps micro-organisms away from food, and protects
delicate or fragile items from knocks and damage. Glass packaging
in bathrooms, where people are barefoot, could be dangerous if
broken.
2.5
Hard-boiled eggs could be protected in bubble-wrap and dropped
from increasing heights. Different thicknesses of wrap could be used.
3.1
The lower mass of the plastics bottles (compared to glass) means
less fuel is needed.
3.2
The cost of manufacture, transport and disposal of plastics and
glass bottles needs to be known.
3.3
Plastic bags...
•
are stronger than paper bags - but the handles can break
under a heavy load
•
don’t tear when wet as paper bags can
•
can adjust to the shape of the shopping more easily than paper
ones - but some paper bags are more rigid than plastic ones
•
are easier than paper bags to use again for another purpose
•
weigh less and take up less space when flat.
3.4
You will need to compare like with like. Only compare bags which
can be used to carry equivalent loads.
3.5
The mass of packaging would increase by around 300%.
3.7
A from factory to
Transport costs are less because
warehouse to storage the lighter load would need less
in the shop
fuel to transport it. Plastics bottles
can be made larger than glass
ones, meaning even lower product
to packaging ratios
B
from storage in the
shop to the shelves
The human effort needed to move
plastics bottles is less than that
needed to move glass ones. This
means that the work is done more
quickly and at a lower cost.
C
from shelves to
check-out to home
and storage
AS B, but also, the wear and tear
on the shopper is less as they have
lighter loads to carry.
3.8
Metal will be similar to glass; card similar to plastics. None of the
containers is as heavy as glass. None of the plastics is as heavy as
metal.
All of these taken on their own make very little difference, but taken
together when enough people do them, the impact can be
considerable.
3.9
Suggestions include
Advantages
Disadvantages
Plastics
easy to mould
in the past less care has
been taken in disposal
Glass
transparent
fragile
Metal
strong
sharp edges when cans
are opened
Card
light weight
complex laminated
material
3.1
Bottles are lighter than a few years ago. Improved design means less
material is used without reduction in strength and safety. Using less
material also means large savings in energy costs for transport.
4.1
Plastics are increasingly being used in today’s vehicles because they
provide benefits in terms of design, safety, aerodynamics, cost and
the environment. The use of plastics in cars, for example, has
quadrupled in the past 20 years.
Using plastics makes them lighter, which saves fuel consumption and
reduces emissions. Parts made from plastics also require less paint and
protective coating, which saves time and materials in manufacturing.
3.10
Advantages
Disadvantages
Plastic containers are easy
to produce in all sizes and
interesting shapes.
They are strong and
flexible, and are safe
when broken. They offer
good protection to
contents against microorganisms and light.
Generally lower recycling
rates than other
materials. There is still
progress to be made in
improving recycling and
other forms of recovery
at the end of life.
4.1
Temperature vs time graphs can be plotted. The gradients of such
graphs will show the relative rates at which heat energy is lost
from the various containers. The same amount of liquid should be
used each time, and measurement should start and end at the
same temperature. The material under test should be used as a lid
to the container to minimise heat loss by convection during the
experiment.
Between 1974 and 1988 petrol consumption in cars dropped by 14
per cent. It is estimated plastics contributed to at least half of the
fuel savings through lighter weight and aerodynamics.
Bumpers, bonnets and boot lids are now based mainly on plastics.
Safety components such as air bags, seat belts and side impact
protection are made possible by the flexibility of plastics. Today,
windscreens are frequently made from shatterproof plastics
compounds.
Besides cars, plastics are used widely in other types of transport. For
instance, the inside shell of planes is constructed with a flexible
plastic to allow stretching at supersonic speeds; the hulls of boats
and the noses of high speed trains are moulded in one piece from
plastics to make them more aerodynamic.
5.1
You might use the word ‘responsive’ rather than ‘intelligent’. These
polymers respond to conditions around them (e.g. temperature,
amount of sunlight falling on them). Clear plastics material, for
example, becomes opaque and reduces the amount of light (and
heat) getting through. Photochromic lenses in glasses already do
something like this, by becoming darker.
Card 5
1.1
People are re-discovering old habits such as:
• composting their organic kitchen waste (vegetable peelings,
banana skins, e.t.c.) and using the compost to enrich their
garden soil
•
using shredded garden debris (tree trimmings, grass cuttings
e.t.c.) as a mulch on the garden to retain moisture in the soil,
and to feed the soil
•
walking to the shops instead of using a car, using public
transport whenever possible and practicable, using bikes when
it is safe and sensible
•
collecting rainwater and/or waste water for the garden
•
re-using plastic bags when they go shopping
There are also some new habits to be acquired:
• using long-life / low-energy bulbs in the house
•
sharing cars to go to work
•
turning lights and heaters off when they’re not being used
•
maximising the use of insulation at home to reduce heat loss
•
recycling materials where it makes sense and is convenient (i.e.
don’t drive miles just to recycle a bottle or two)
Card 6
1.1
Thermoplastic materials can be softened and re-used as the
polymer; thermosets cannot. Getting these two products mixed up
would cause a mess which would be impossible to separate. Even
different thermoplastics are not compatible with each other when
melted together. Although the mixture can be moulded in special
processing equipment, its physical properties are much worse than
those of the individual pure plastics. Even if there is just a low
amount of a different polymer present, the properties of the
recyclate are adversely effected.
1.2
If plastics are separated, the options for processing are much
greater. They can be processed into the original polymer, or broken
down into basic chemical components. The option of using as a
fuel is still possible if the above recycling routes are not attractive.
1.3
Again, the options available with clear plastics are so much greater.
You can easily make a dark coloured plastic from a light coloured
one but not the other way round.
1.5
A good example of this is an ice cream tub where the tub is made
of high density polyethylene (code 2) and the lid of low density
polyethylene (code 4). Because of this, the lid is more flexible than
the tub which is a useful property as the lid has to be flexed to
remove it each time you want to eat the ice cream.
2.1
3
The density would need to be between 0.91 and 1.05 g/cm .
2.2
3
A density of between 1.05 and 1.34 g/cm .
5
Recycling of waste
Recycling can separate out valuable resource materials from
waste; e.g. metals such as aluminium, copper and tin as well
as glass, paper and plastics
Recycling can reduce industrial manufacturing costs
Collecting for recycling is something everyone can do
2.3
Don’t mix different plastics with very similar densities.
Use water-soluble inks.
Light colours are easier to handle than dark ones.
Print information onto plastics rather than on labels or use water
soluble glues for labels.
2.4
[i] the price will fall - making the process less economic
[ii] this will rise - increasing costs
[iii] these will rise
[iv] this will fall - putting the whole enterprise into jeopardy
In environmental terms recycling does not always make
sense; e.g. if you make a special journey by car to a
recycling centre you run the risk of using more energy on
fuel than you save in the recycling process
The demand for recycled materials can be uncertain,
e.g. because of changes in the price of raw materials
processed or lack of suitable outlets. This is because there is
a maximum amount of recycled plastics which can be
incorporated into products. Often, the plastics are recycled
into completely different applications e.g. bottles to fibres
Energy recovery from waste through burning
2.5
The public will begin to question the point of recycling and rapidly
become disillusioned. Recycling organisations will lose credibility
and public support.
3.2
We need to know about the costs of processing for each of these
methods, and the costs of other raw materials used (e.g. hydrogen).
For feedstock we also need to have a contractual agreement for
regular supply, which will include the specification of material to
be used.
This is useful if the energy released is captured and used as
heating or as a means of generating electricity
To be efficient, this needs to be done near population
centres
Installation needs to take account of strict emissions levels
and monitoring requirements set out in European legislation
Energy from waste reduces the volume and mass of waste
for final disposal
Using waste for energy saves fossil fuels
4.2
The missing data are:
amounts
(‘000 tonnes)
1994
1995
1996
1997
total plastics waste
17505
16056
16871
17454
mechanically recycled
1057
1222
1320
1440
feedstock recycled
51
99
251
334
energy recovered
2348
2698
2496
2575
total plastics recovered
3456
4019
4067
4349
% waste recovered
20%
25%
24%
25%
Card 7
1
You could divide the class into 5 different working groups each to
take on two local areas (e.g. the school itself, the roads around the
school, a local park or amenity area). This activity will need some
planning and due consideration must be given to health and safety
aspects. Pupils must be supervised.
For each location, students will need:
A a simple grid or checklist to record the types of litter that are
present in the area. The most frequent items of litter are:
• Drinks cans
•
Cigarette butts
•
Bits of paper
•
Chewing gum
•
Plastic packaging
•
Glass items and broken pieces
B to make an assessment of the area in terms of the Tidy Britain
Litter Index criteria. In order to ensure sure some degree of
standardisation, it would be useful if the students and teacher
visited an area (this could be the playground or the front area of
the school) and made a collective judgement as to the description
of the area (in terms of the index) so that the same criteria are
applied to all areas the students visit.
C to quantify the amount of litter by measuring out a specific
area (50 metres by 1 metre) and counting the number of the
different items in this area. They could produce bar charts to
compare the different locations.
On return to the classroom, the data can be collated for the
different areas and students can address the questions in
Activity 1. The answers to these will obviously depend on the area
but the most common items found tend to be cigarette butts,
matchsticks, small bits of paper, sweet wrappers and plastic bags.
Each area should be given a rating according to the Tidy
Britain Litter Index.
Items which can be dangerous to people or wildlife include
broken glass, glass bottles (small animals may enter them and then
be unable to escape), and discarded syringes/ medical material (risk
of Hepatitis, HIV etc). Sometimes large items of household
equipment (like fridges and freezers) are dumped. This is not really
litter but can be especially dangerous to young children who may
get trapped inside them. One item that is difficult/expensive to
remove is chewing gum (this takes time – each piece needed to be
scraped off or hosed away using high-pressure equipment). If glass,
paper and plastic items of litter are collected they can re-enter the
waste management system and many can be recycled one way or
another.
The ratings for each area (A, A-, B, C, D) are then converted
into numerical scores (5, 4, 3, 2, 1). These are then used to work
out the cleanliness index for the neighbourhood as explained on
the card.
2
This could be a group-based activity. Each group could be assigned
an environment and asked to brainstorm/consider the various types
of litter that they might expect to find there, how the litter got
there (who might have brought and left it, and why), and whether
or not it is biodegradable/recyclable, etc.
This could lead on to a discussion about access to different
areas, and how this has changed in the last 50 years. For example,
has there been an increase in the number of people with cars and
in the amount of leisure time? This could also include a discussion
on controlling litter through the provision and emptying of
litterbins, litter patrols and local laws.
Measures to reduce litter will again depend, in part, on the
nature and type of litter, but simple things such as the provision of
litter bins and the employment of individuals to regularly empty
them to prevent them overflowing could be discussed.
The responsibility of individuals, retail outlets and restaurants to
dispose of their waste, as well as the responsibility of pet owners
to dispose of animal faeces hygienically, could also be considered.
The effects of litter (see left) can be discussed and extended, for
example, plastics fishing lines or nets at the seaside and in rivers
lead to entrapment of animals and foul propellers. Fishing nets cut
free by trawlers trap large numbers of marine mammals. Reference
might be made to specific areas like the Norfolk Broads, where
pleasure craft are responsible for large amounts of litter. People
end up destroying or spoiling what they have come to see.
3
The following outlines the management of litter in the UK and
provides contact details for organisations that either operate
national litter schemes or produce literature addressing the issues.
Under the 1990 Environmental Protection Act, littering is a
criminal offence subject to a maximum fine of £2,500. Local
councils are responsible for keeping their streets clean and can be
prosecuted for failing to do so. All state funded schools and
universities have similar responsibilities for their grounds. The Tidy
Britain Group, the recognised national agency, is a registered
charity and an independent voluntary body. It uses campaigns,
action programmes and education to fight litter and littering. You
may be interested in joining the 40 million people in 120 countries
who join forces each year under the banner of ‘Clean up the
World’ to make a real difference to our environment. Further
information on this and other schemes can be obtained from:
Clean Up the World (an international campaign co-ordinated in
Australia)
Fax: 00 61 2 9692 0761
email: [email protected]
http://www.cleanuptheworld.org.au
The Tidy Britain Group, Head Office, The Pier, Wigan, WN3 4EX
Tel: 01942 824 620
http://www.tidybritain.org.uk
Waste Watch, Europa House, Ground Floor, 13-17 Ironmonger Row,
London, EC1V 3QG
Tel: 0171 253 6266
http://www.wastewatch.org.uk
Environment Agency, Rio House, Waterside Drive, Aztec West,
Almondsbury, Bristol, BS12 4UD
Tel: 01454 624 400
http://www.environment.agency.gov.uk (worksheets can be
downloaded)