146
SPOTLIGHT
FIRE
FIRE-RESISTANT
COMPOSITE MATERIALS
HIGH-PERFORMANCE COMPOSITE MATERIALS, CONSISTING OF REINFORCED CARBON OR GLASS FIBRES IN A
POLYMER RESIN MATRIX, ARE AN ESTABLISHED TECHNOLOGY FOR PRODUCING LIGHTWEIGHT STRUCTURES.
HOWEVER, CURRENT FIBRE-REINFORCED POLYMER (FRP) COMPOSITES ARE TYPICALLY COMPROMISED TO
VARYING DEGREES WITH RESPECT TO THEIR FIRE PERFORMANCE. THE AIM OF THE FOUR-YEAR EUROPEAN
PROJECT FIRE-RESIST* IS TO DEVELOP STRUCTURAL COMPOSITE MATERIALS THAT EITHER ARE THEMSELVES
FIRE-RESISTANT, OR PROVIDE THE MAXIMUM PROTECTION WITH A MINIMUM WEIGHT PENALTY.
©EURAILmag
FIRE-RESIST partners
“A
NewRail Centre for Railway
Research of Newcastle University
(coordinator)
EADS Deutschland GmbH – Innovation
Works
Bombardier Transportation (UK) Ltd
Flensburger Schiffbau-Gesellschaft mbH &
Co. KG
Germanischer Lloyd AG
Cytec Industrial Materials (Derby) Ltd
Amorim Cork Composites SA
TransFurans Chemicals BVBA
Anthony, Patrick and Murta Exportação Lda
APC Composite AB
BALance Technology Consulting GmbH
PROPLAST – Conzorzio per la Promozione
della Cultura Plastica
Fundación Gaiker
Institut National des Sciences Appliquées
de Lyon
SP Sveriges Tekniska Forskningsinstitut AB
Swerea SICOMP AB
VTT Technical Research Centre of Finland
Steinbeis Advanced Risk Technologies GmbH
lthough the benefits of using
respects such as weight, surface finish, or
The project consortium, led by NewRail,
polymer composites in rail and
processability. Yet for trains, planes, and
consists of 18 partners from nine coun-
other transport mode structur-
boats, weight savings in particular translate
tries, including leading organisations from
al applications are well known – lightweight,
into lower operational costs and reduced
the three industries involved (see box).
corrosion resistant, ease of fabrication of
energy consumption. Bringing together
The rationale was to bring together vehi-
complex shapes – the main obstacle to their
the aerospace, maritime, and rail industries,
cle/vessel manufacturers from the three
wider adoption is uncertainty over their fire
FIRE-RESIST, which runs from February 2011
aforementioned industries, together with
performance,” says Dr George Kotsikos,
up to January 2015, is working to develop
industry certification bodies, suppliers of
from FIRE-RESIST coordinator NewRail of
new material concepts together with ad-
fire-resistant composite materials, produc-
Newcastle University (U.K.). “If it can be
vanced simulation methodologies to help
ers of composite mouldings, developers of
demonstrated to industry that passenger
to reduce the requirement for costly fire
new composite materials and processes,
safety would not be compromised, then a
testing. “Rather than tackling these issues
plus specialists in fire testing, in fire sim-
wider acceptance of the materials in prima-
in an isolated, fragmented fashion, there
ulation, and in managing the risk of new
ry structural designs would be acceptable.”
is clear merit in a coordinated approach so
product development and introduction.
that experiences, facilities, and solutions
Those composites that currently perform
can be shared across the transport sectors,”
Funding has been provided to the sum
better in fire tend to be poorer in other
points out Dr Kotsikos.
of €7.8 million, with support provided by
ISSUE 27 / / / EURAILmag B­usiness & Technology
F I R E | 147
the European Commission under its 7th
with tools to engineer the best fire protec-
Framework Programme.
tion regime with minimum weight penalty.
The investigation into new formulations
FIRE, HEAT & FLAME SPREAD
of materials is centred around the following three technologies, aspects of some of
The less than satisfactory fire performance
which are patent pending:
of polymer composites is due to their organ-
M
ulti-layer metallic laminates
ic matrix resins, which first soften on heating,
These are a novel advancement of a semi-
causing a loss of mechanical properties and
structural material that is bonded onto to a
then, at higher temperatures, decompose.
composite or a metallic structural substrate.
Decomposition results in the production of
The laminate contributes to the structural
smoke and toxic or flammable decomposition
strength of the substrate, but in the case of
products. The latter are not only hazard-
fire, it degrades in a manner that offers maxi-
ous in terms of lack of visibility and toxicity;
mum protection to the underlying structure.
they can also burn, releasing heat, which can
 New chemical compositions of fire-resistant
lead to flame spread and exacerbate the
polymer resins
fire. Furthermore, loaded composite struc-
These will be used for the fabrication of
tures often collapse in a fire within a period
composite components and structures,
of minutes, depending on the magnitude of
without any compromise in mechanical
sure and heat are applied. The polymer
the load and heat flux. “Comparisons in fire
strength.
fibres melt with the heat and the melt flows
performance of composite structures are usu-
C
ommingling technology
around the glass (or carbon) fibre, achieving
ally made with steel structures,” expands Dr
Commingling refers to fibre reinforcement
a very good ‘fibre wet out’ and eventually
Kotsikos. “Although steel does not burn, it is a
mats made up of a mixture of glass (or car-
forming the matrix of the composite. New
good conductor of heat and therefore spreads
bon) fibres and polymeric fibres (usually
formulations of fire-resistant fibre systems
fire to adjacent compartments. Composites,
thermoplastic fibres) mingled together.
are being developed to incorporate novel
on the other hand, do not conduct heat,
The mat is then placed in a mould and pres-
composite applications.
The European scope of FIRE-RESIST
which limits the spread of fire, but lose their
strength at relatively low temperatures. There
is no reason, though, that composite materials
cannot be used in structural applications with
the incorporation of suitable fire protection
systems, in a similar way to the approach followed for aluminium alloys.”
Structural
surface
laminate
Delaminateted surfaces
struscture with low
thermal conductivity
Bulk
composite
Bulk
composite
The work of FIRE-RESIST is being carried
out in the U.K. and several other European
New material developments 1: structural surface laminates
Union countries. It entails fundamental research activities in understanding the fire
behaviour of the materials being developed;
fundamental research on polymer chemistry to elaborate novel, fire-resistant resins;
laboratory work to characterise the properties of said materials at high temperature;
fire tests on samples of them; and predictive
model development (based on the under-
Composite
Significant protective
char formation
standing of the fundamental properties
of the new materials) to provide designers
New material developments 2: high char-forming composites
EURAILmag B­usiness & Technology
///
ISSUE 27
148
SPOTLIGHT
FIRE
Consolidate: heat and pressure
+
Particle-doped fire
retarded polymer
fibres
duce lower overall CO2 emissions, cause less
damage to the tracks, and prove cheaper for
=
Fibre reinforcements
(carbon or glass)
consume less energy/fuel in operation, pro-
operators to run.
Commingled polymer/
reinforcement fibre
preform
High-performance
fire-retarded fibre
reinforced polymer part
New material developments 3: particle-doped commingled composites
When seeking to build a lighter train, optimising their specifications or their design,
e.g. multifunctional components, joints and
fixtures, or wireless versus cabled technologies, are two valid and proven approaches;
the third is to optimise the material selec-
Now that the project has reached midterm,
such work very difficult to be undertaken
tion. In the rail industry, FRP composite
“some new materials have been elaborated
by a single entity.” Furthermore, given the
materials are a well-established enabling
and are currently being tested under the
complexity and size of the initiative as a
technology for lightweighting; indeed, in
‘materials characterisation’ phase,” reports
whole, good communication is instrumen-
trains they are nothing new – in the U.K.,
Dr Kotsikos.
tal is achieving successful outcomes, as its
rolling stock with FRP doors was running
In the 4th and final year, the most promising
coordinator confirms: “There are weekly,
from as early as the 1950s. Today these
material developments from the first three
or in some instances daily, e-mail commu-
composites are routinely employed for
years will be applied to relevant transport
nications between consortium members
semi-structural and decorative train appli-
sector case study components, of which at
focusing on specific tasks. In addition, regu-
cations such as fairings, interior panels, and
least one will be designed and prototyped
lar monthly web meetings take place, where
seat shells. But, apart from a few, one-off
for the rail, aerospace, and marine sectors,
partners discuss results and problems within
prototypes, fully structural composites have
respectively. These components also will
their work package. Also, twice a year physi-
yet to significantly penetrate the rail market,
be subjected to a full-scale fire test to vali-
cal meetings of the whole consortium take
largely due to their relationship with fire.
date the performance of the FIRE-RESIST
place where progress is presented, and vari-
materials.
ous issues discussed.”
INTERDEPENDENCY
& COMMUNICATION
WEIGHING UP THE FACTORS
By working towards improving the fire performance of FRPs without compromising
the structural (or wider) performance of the
composite, FIRE-RESIST will make a valuable
Over the past 30 years, trains have gener-
contribution towards saving and protect-
While work on the above three technolo-
ally gotten heavier. This weight gain is due
ing resources – environmental, financial,
gies is being carried out simultaneously at
to factors such as crashworthiness (e.g.
and labour – that are certain to become in-
various research centres around Europe, the
crumple zones), performance (e.g. tilt-
creasingly valuable in this generation, and
latter are interdependent since the partners
ing mechanisms), and passenger comfort,
the next
make use of each other’s facilities to under-
convenience, and accessibility (e.g. power
take specific research tasks. “A project such
points, air conditioning, and disabled toi-
Lesley Brown
as FIRE-RESIST is one example of the mer-
lets). Yet there are strong commercial and
All illustrations ©FIRE-RESIST – unless marked
its of international collaborative research,”
environmental justifications for seeking to
points out Dr Kotsikos, “because the com-
reduce the mass. Compared to their weight-
plexity of the technologies involved makes
ier counterparts, lighter rolling stock would
Intermediate fire barrier
Carriage with fire
“Safe” Carriage for evacuation
ISSUE 27 / / / EURAILmag B­usiness & Technology
*more details can be found at www.fire-resist.eu; the
project can also be followed on Twitter, Facebook, and
has a LinkedIn group
Acknowledgements
The FIRE-RESIST partners would like to thank the European Commission for supporting the project under the
7th Framework Programme