„New generation of
aluminium hydroxide
flame retardant filler
for the wire and cable industry“
Dr. Reiner Sauerwein
Nabaltec GmbH
Cables 2003
Business Unit Fillers
Overview
• Introduction
• New ATH quality – product characteristics
• Powder handling properties during compounding
- conveyance
- feeding / metering
- dust behaviour
- filler uptake
• Compound properties
• Options for high performance ATH
- low process costs of standard LSFOH
- new compound developments
• Conclusions
Cables 2003
Business Unit Fillers
Introduction – Market Share of LSFOH
PE-consumption in 2001
Total 325.000 tons
for Western Europe
LSFOH 12%
XPE 41%
Germany
MD/HDPE 18%
15%
LLDPE 9% LDPE
Schwandorf
â
More than
70.000 tons of
ATH in PE-based
LSFOH compounds
Cellular PE 5%
A. Reynolds, „Raw materials
usage in the European cable
industry“ ; Cables 2002
Cables 2003
Business Unit Fillers
Introduction - cost factors of LSFOH
cable production
Raw material costs
• polymers
• ATH
• additives (stabilizers, coupling agents,...)
Process costs
ââ
Compounding costs
• energy consumption
• compound throughput
Reduction of process costs
„powder handling“
ATH showing
• good conveyance
• good metering / dosing
• fast uptake
in polymer melt
€ / unit
è
Extrusion costs
9 Compounds
• energy consumption
• extrusion speed / output
units / time
• high melt flow
• good rheology
• good extrusion
„compound performance“
Cables 2003
Business Unit Fillers
Powder handling during Compounding - problems
• low bulk density
• dust emission
• flowability / conveyance
Þ Common Solutions
A) Physical Densification
- higher filler mass throughput during volumetric feeding
- better flow properties,
- non consistent bulk density during air suction/pressure conveyance
P
P
O
B) Organic Coating
- good flow
- low viscosities in compounds,
- sometimes poor mechanical properties
- poor electrical insulation properties (high water uptake)
Cables 2003
Business Unit Fillers
P
P
O
O
New Solution – Apyral® 40CD - characteristics
Apyral 40D
Apyral 40CD
1.2 - 1.5
1.0 – 1.3
3 – 4.5
3.5 - 5
Bulk density (g/l)
400
400
Moisture (%)
0.2
0.2
26 - 30
0.6 – 0.7
19 - 23
0.4 – 0.5
d50 (µm)
BET (m2/g)
Oil absorption (%)
Water uptake (ml/g)
No coating!
No densification!
1
Apyral 40D
wateruptake (ml/g)
Apyral® 40CD
shows extremely
low oil absorption
for a fine
precipitated ATH
quality !!!
0,8
Water Uptake measured
according to „Baumann“
(in line with DIN 53495)
0,6
0,4
Apyral 40CD
Significantly lower
water uptake of
Apyral 40® CD !!!
0,2
0
0
10
20
30
40
50
60
t (min)
Cables 2003
Business Unit Fillers
Compounding – critical process parameters
delivery/
storage/
input
of raw
materials
Silo
flow
BB-station
bulk
density
flow
dustemission
flow
Silo-truck
consistency of bulk
density
day-bin
preparation
of raw material
flow
bulk
density
dry mixing
Pipe conveyance
-air suction
-air pressure
dosing
compounding
compound
Cables 2003
Business Unit Fillers
Conveyance trial
BB station
1
Air suction conveyance:
- Length 60m,
- pipe diameter
60mm
- vertical and
horizontal
elements
- 90° corners: 11
2
450
Receiving
set
bulk density
400
Vibration
bottom
350
300
Apyral® 40CD
Apyral® 40D
3
250
CD = consistent density
200
1
2
Cables 2003
BB
3
Business Unit Fillers
Flow behaviour – feeding during continuous
compounding
Gravimetric dosing of ATH
via two dosing units within
a buss-kneader-line (fixed
mass flow)
15-20% lower screw speed
needed for Apyral® 40CD!!!
Apyral 40D
screw speed (rpm)
500
Apyral 40CD
400
300
200
100
0
D1
D2
unit
Cablesdosing
2003
Business Unit Fillers
Dust behaviour – measurement according to
DIN 33897 – part 2
Benefits of this method
•
•
•
•
Simulation of discharge-, filling- and
conveyance- processes
Selective sampling and determination of
breathable (SE ; Def. acc. to DIN EN 481)
and alveoli passing dust (SA)
High sensitivity and reproduce ability
Further analyses of dust particles
possible
Lit:“Das Staubungsverhalten quarzfeinstaubhaltiger
Produkte“; Gefahrstoffe-Reinhaltung der Luft 60
(2000) Nr. 5, Mai.
Apparatus ; with the kind permission of
IGF Institut für Gefahrstoff-Forschung
der Bergbau-Berufsgenossenschaft
Cables 2003
Business Unit Fillers
Dust behaviour – results
Filler
SA
(mg/kg)
SE
(mg/kg)
Apyral® 40CD
< 0.3*
100
Apyral® 40D
< 0.3*
118
TiO2 (d50 = 1µm)
1.04
88
BaSO4 (d50 = 8µm)
8.7
205
39.8
704
Carbon black (d50 =
1.7µm)
*non traceable
Apyral® 40CD shows a 15 - 20% reduction of
breathable dust compared to standard ATH
qualities as e.g. Apyral® 40D !!!
Compared to other fillers, both ATH qualities are very low in SA dust and low to medium with regard to SE – dust!
Cables 2003
Business Unit Fillers
Compounding behaviour - Power Consumption
of Buss-kneader MDK 46
Apyral 40D
Apyral 40CD
Ø = 2,9kW
Ø = 2,7kW
Electrical power
uptake of
screw motor
Compounding
behaviour of
Apyral® 40D
is good
Cables 2003
Compounding behaviour
of Apyral® 40CD
better than
Apyral® 40D
Business Unit Fillers
Compound properties – EVA
EVA (19%VA) ; Aminosilane coupled
60 wt.-% ATH
Tensile strength
Elongation at bre ak (%)
12
Te nsile stre ngth (M Pa)
Elongation at break
250
14
10
8
6
4
200
150
100
50
2
0
0
Apyral 40D
4,5
190°C
3,5
3
Compounding in batch
dispersion kneader ;
specimens cut out of
compression moulded plates
Melt flow index
4
M VI (cm /10min)
Apyral 40D
Apyral 40CD
Apyral 40D
Apyral 40CD
Apyral 40CD
No impact on
„mechanics“!
3
2,5
160°C
30% increase
in MFI for
Apyral® 40CD!!!
2
1,5
1
0,5
0
1
Cables 2003
2
Business Unit Fillers
Compound properties – PE / EVA
PE/EVA ; Vinylsilane coupled
60 wt.-% ATH
12
Tensile strength
10
250
Elongation at break (%)
Tensile strength (MPa)
Elongation at break
300
8
6
4
200
150
100
50
2
0
0
Apyral 40D
Apyral 40D
Apyral 40CD
Melt flow index
Apyral 40D
Apyral 40CD
10
No impact on
„mechanics“!
160°C
More than
50% increase
in MFI for
Apyral® 40CD!!!
MVR (cm3/10min)
8
Continuous compounding in
Buss-co-kneader MDK46 ;
specimens cut out of extruded
tapes.
Apyral 40CD
6
4
2
0
Apyral 40D
Cables 2003
Apyral 40CD
Business Unit Fillers
Flame Retardant Properties
Limiting Oxygen Index = LOI
ASTM D 2863-77
LOI of Apyral® 40CD
containing compounds
slightly enhanced
EVA (19%VA)
40
Aminosilane
Apyral 40D
Apyral 40CD
40
39
Vinylsilane
39
38
38
37
LOI (%O2)
LOI (%O2)
PE/EVA
36
35
34
37
36
35
34
33
33
32
Apyral 40D
32
Apyral 40CD
Apyral 40D
Cables 2003
Apyral 40CD
Business Unit Fillers
Good melt flow properties – options
5,5
EVA (19%VA) ; 60 wt.-% ATH
5
4,5
Apyral 40CD
4
3
MVR (cm /10min)
Melt Flow
as a function
of silane
content
3,5
Apyral 40D
3
2,5
2
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
Aminosilane (%)
Low process costs for
standard LSFOH compounds
Highly filled and flame
retarded LSFOH compounds
a Higher extrusion speeds
a „Freedom“ to increase filler level
a High productivity
a „Freedom“ to add synergistic
(mineral) additives
a High competitiveness against
alternative FR - compound
Cables 2003
Business Unit Fillers
Melt Rheology – PE / EVA
PE/EVA ; 60 wt.-% ATH ; Vinylsilane coupled
Capillary Rheometer ; 150°C
Shear Viscosity η s (Pas)
10000
1000
Apyral 40D
Apyral 40CD
100
10
100
1000
Apyral® 40CD
shows lower
compound
viscosity than
Apyral® 40D
over the
whole shear
velocity range
10000
Shear Velocity dγ/dt (s-1)
Cables 2003
Business Unit Fillers
Extrusion properties – PE / EVA
Set-up
ØExtruder with BM-screw at 30 rpm;
Ø0,5mm2 copper, round;
ØDiameter tip 0,85mm
ØDiameter die 1,4mm
Line speed: 650 m/min
Tm = 168°C
p (bar)
850
X
X
170
160
Tm = 151°C
800
pm = 800bar
X
p = 740bar
m
750
Apyral 40D
150
140
Apyral 40CD
700
Melt pressure and
melt temperature of
Apyral® 40CD is lower
than for Apyral® 40D
T (°C)
900
_ „freedom“ to
enhance line
speed by extruder
screw speed !!!
130
Cables 2003
Business Unit Fillers
Good melt flow properties – options
5,5
EVA (19%VA) ; 60 wt.-% ATH
5
4,5
Apyral 40CD
4
3
MVR (cm /10min)
Melt Flow
as a function
of silane
content
3,5
Apyral 40D
3
2,5
2
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
Aminosilane (%)
Low process costs for
standard LSFOH compounds
Highly filled and flame
retarded LSFOH compounds
a Higher extrusion speeds
a „Freedom“ to increase filler level
a High productivity
a „Freedom“ to add synergistic
(mineral) additives
a High competitiveness against
alternative FR - compounds
Cables 2003
Business Unit Fillers
EVA – 65wt.-% filler: mechanical properties
ATH
Elongation at break (%)
160
ATH+AOH
ATH+AOH
+ZnB
Apyral 40D
155
150
„Bi-blends“ of
Apyral® 40CD and
Apyral® AOH180 (=AOH)
and
... „tri-blends“ with
Zinc borate (=ZnB)
145
140
135
130
125
120
14,5
14
Tensile strength (MPa)
Apyral 40CD
show good balanced
physical properties at
65wt.-% filler content !!!
13,5
13
12,5
12
Compounding in batch
dispersion kneader ;
specimens cut out of
compression moulded plates
11,5
11
10,5
Cables 2003
Business Unit Fillers
EVA – 65wt.-% filler: LOI ; MVR
ATH
ATH+AOH
50
ATH+AOH
+ZnB
LOI = 43,2 %O2
PHRR = 170 kW/m2
TTI = 78 sec
48
LOI (%O2)
46
44
LOI = 48,2 %O2
PHRR = 173 kW/m2
TTI = 80 sec
42
40
38
MVR
cm3 /
10min
2.0
2.4
1.4
1.7
1.9
2.1
Apyral® 40CD allows highly filled compounds
• having good melt flow properties
• showing good flame retardancy,
9
especially when combined with fine
boehmite filler (Apyral® AOH 180)
Cables 2003
Heat flux = 50 kW/m2
Horizontal orientation
Specimens cut out of
compression moulded plates
Business Unit Fillers
Conclusions
Apyral®40CD is a new non post treated fine precipitated ATH quality,
offering
• good conveyance properties without any loss on bulk density
• good flow, discharge and feeding properties
• low dust emissions during powder handling (discharge etc.)
• good filler uptake and dispersion (low power uptake, low torque)
9-
lower compound process costs (high throughput in
continuous lines, low batch times in case of internal mixers)
• good mechanical and flame retardancy properties and
• outstanding low melt viscosity of standard LSFOH compounds
• high extrusion speeds of standard LSFOH compounds
9lower extrusion costs
• an option for processable, highly filled and flame retardant LSFOH
compounds - especially when combined with other fillers
Cables 2003
Business Unit Fillers