Arkema functional polyolefinsfor cable compounds
EVATANEEVATANE®®
LOTRYLLOTRYL®®
LOTADERLOTADER®®
OREVACOREVAC®®
October 2002
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Evatane®- Lotryl®- Lotader®- Orevac®
HFFR: Halogen Free Flame RetardantWhy HFFR? p 3Atofina functional polyolefins for cables p 6Standard formulation p 9Resin selection p 11Coupling agents p 14Ageing p 17Crosslinking p 18Temperature requirements p 21
Power cableArkema resins in power cable p 22Internal semi conductor layer p 24Insulation layer p 25External semi conductor layer p 26Sheathing/jacketing p 27
The information contained herein is to the best of our knowledge accurate, but since the circumstances and conditions in which it may be used are beyond our control, we do not accept liability for any loss or damage, however arising, which results directly or indirectly from the use of such information, nor we offer any warranty of immunity against patent infringement.
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Why halogen free compounds?
PVC is still the main resin used in the cable industry.However, three main drawbacks have forced the development of alternative halogen free materialsFire behavior of PVC :
Formation of black smokeRelease of chlorine derivatives
Environmental considerations :PVC under environment pressure
Limited temperature resistance (110°C)
With its range of functional polyolefins, Arkema stands as a partner of choice to cable manufacturers who expect innovative solutions to the most complex of problems.
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HFFR:Alternative to PVC
Polyolefins (PE, EVA, EMA, EBA) are good candidates for the substitution of PVC in cables. Benefits are:
Good combustion properties• Low smoke emission• Anti-drip
Excellent dielectric propertiesGood physical properties - CrosslinkableRecyclability Good performance/price balance
But limited natural fire resistance: the addition of mineral flame retardants such as Al(OH)3, Mg(OH)2 and/or others is necessary to meet flame retardancy requirements.
As they accept high content of filler (due to their high polarity), EVATANE ®and LOTRYL ® are the materials of choice
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Where HFFR
Medium -High Voltage cable>1KV to 600 KV
For medium voltage or high voltage, only the sheathing layer (7) is halogen free.
Low voltage < 1KV
HFFR can be used in insulation, bedding and sheathing of low voltage cables
1
2
3
45
6
7
6
Grades
VA Content (%)
Melt Index (g/10 min)
Melting point (°C)
Vicat point (°C)
Tensile Strength at break (Mpa)
Elongation at break (%)
Hardness Shore A
18-150 17 – 19 135 – 175 79 43 5 500 – 800 84
18-500 17 – 19 450 – 550 74 < 40 4 500 – 800 80
20-20 19 – 21 17 – 23 79 49 12,5 500 – 800 84
24-03 23 – 25 2,5 – 3,5 79 45 29 700 – 800 85
28-03 26 – 28 3 – 4,5 75 44 33 700 – 1000 83
28-05 27 – 29 5 – 8 73 43 33 700 – 1000 82
28-25 27 – 29 22 – 29 72 41 13 700 – 1000 76
28-40 27 – 29 35 – 45 72 40 11 700 – 1000 76
28-150 27 – 29 135 – 175 67 < 40 6 700 – 1000 70
28-420 27 – 29 370 – 470 67 < 40 2,5 700 – 1000 62
28-800 27 – 29 700 – 900 64 < 40 1,5 300 57
33-35 32 – 34 22 – 29 60 < 40 12 800 – 1000 66
33-45 32 – 34 38 - 48 60 < 40 10,5 800 – 1000 64
33-400 32 – 34 350 - 450 59 < 40 2,5 800 – 1000 45
40-55 38 - 41 48 - 62 50 < 40 5 1000 46
EVATANE: wide range of vinyl acetate content and melt index
Evatane®: EVA copolymers
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Base Grades Ester content Melt index Melting Tensile strength Elongation at Flexural% (g/10 min) point (°C) at break (Mpa) break (%) modulus (Mpa) Shore A Shore D
7 BA 01 6 - 8 1 - 1,5% 107 17 700 85 - 42E 17 BA 04 16 - 19 3,5 - 4,5 91 13 700 45 - 32B 17 BA 07 16 - 19 6,5 - 8 89 12 700 40 - 30A 30 BA 02 28 - 32 1,5 - 2,5 78 6 850 9 75 -
35 BA 40 33 - 37 35 - 45 67 2 300 - 70 -9 MA 02 8,5 - 10,5 1,8 - 2,6 99 16 750 88.5 - 3815 MA 03 13,5 - 16 2,3 - 3,3 89 14 700 50 - 29
E 16 MA 003 14 - 17 0,25 - 0,35 96 22 650 60 - 35M 18 MA 02 17 - 20 2 - 3 87 15 700 50 - 25A 20 MA 08 19 - 22 7 - 9 80 10 800 20 83 -
24 MA 005 23 - 26 0,4 - 0,6 70 20 700 18 84 -28 MA 07 26 - 30 6 - 8 65 7 900 10 76 -29 MA 03 27 - 31 2 - 3,5 61 6 900 8 75 -
Hardness
LOTRYL are random ethylene / acrylic ester copolymers.--- (CH2 - CH2 -)x ---- (CH2 - CH - ) ---
Ethylene IO = C – O - CH3 or C4H9
Methyl Acrylate Butyl Acrylate
Lotryl® EMA & EBA copolymers
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Lotader® and Orevac®
Maleated polyolefinsLOTADER
Ethylene-butyl acrylate-maleic anhydride terpolymers
- (CH2 - CH2 -)x - (CH2 - CH - ) y - (CH2 - CH2 -) - (CH - CH - )zI I I
C = O O = C C = OI \ /
O - R O Butyl Acrylate Maleic anhydride
LOTADER GRADES
N BUTYL ACRYLATE
(w%)
MALEIC ANHYDRIDE
(w%)
3210 6 3.1
4210 6 3.8
3410 17.7 3.1
OREVAC GRADES
MFI (g/10min)
Tm (°C)
PE 18302 1 124
EVA 18211 3.5 75
PP CA100 10 167
OREVACMaleic anhydride grafted polyolefins
-- (CH2 - CH2)n -- CH2 - CH-ICH - CH2
I IO = C C = O
\ /O
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HFFR standard formulations
Polyolefins + Filler + Coupling agent
Filler acceptance Flame resistance Cohesion
EVATANE®
LOTRYL®
LOTADER®
OREVAC®
50EVATANE® or LOTRYL®
PHRProduct
0,7Stabilizer
170Mineral flame retardant fillerAl(OH)3 or Mg( OH)3.
20OREVAC or LOTADER
30PE ( LD, HD,LL,VLD)
HFFR formulations are based on blends of ethylene copolymers (EVA, EMA, EBA) and Polyethylene (LD,LL,HD) to optimize flameretardancy , mechanical properties and cost .
Standard formulation
10
0
5
10
15
20
25
30
35
40
0 40 60 70
LDPE
EVA, EBA, EMA(30%Comonomer)
ATH content (wt%)
HFFR compounds : LOI*
Soft PVC LOI
LOI*: Limited Oxygen Index = minimum amount of oxygen in atmosphere to maintain combustion
In order to meet fire resistance a high amount of filler is required. EVATANE® and LOTRYL®
(EMA, EBA, EVA) provide better fire resistance due to their high filler acceptance.
LOI (%)
11
0
20
40
60
80
100
120
140
160
10 15 20 25 30 35
Lotryl or EVA Comonomer content (w%)
%E
lon
g. a
t b
reak
Evatane®, Lotryl® selection
Higher comonomercontent increases elongation at break and filler acceptance.
Lower melt index gives higher stress at break.
The selection of an appropriate grade is based on the compromise between acrylate content and MFI.
0
2
4
6
8
10
12
14
16
18
0 0.5 1 1.5 2 2.5 3
LOTRYL or EVA MFI (g/ 10 min @ 190°C/2.16kg)
Stre
ss a
t bre
ak (M
pa)
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Evatane®, Lotryl® selection
Stress and elongation at break (%)for standard formulation
020406080
100120140160180
EVATANE 2803Lotryl 15 MA 03Lotryl 16 MA 003Lotryl 24 MA 005Lotryl 29 MA 03Lotryl 30 BA 02
% E
lon
gat
ion
024681012141618
Str
ess
at B
reak
(Mp
a) Arkema’s product range has been developed to cover the specifications of the cable industry
Recommended resins:Evatane® 28-03, 28-05
Lotryl® 30 BA02, Lotryl® 24 MA005,Lotryl® 29MA03, Lotryl® 16MA003
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Evatane® brings a good performance at a competitive cost.
Due to their better thermal stability, Lotryl® is more appropriate for :
Higher processing temperatures Higher extrusion speed Better heat resistanceBetter chemical resistance.
especially to oil.
Choice of Evatane® versus Lotryl®
Ageing @ 175°C
0
20
40
60
80
100
120
0days 7days 14days 21days 28days 35days
Ageing time
Elo
ngat
ion
at b
reak
%
EVA compound Lotryl compound
Lotryl based compounds have better ageing resistance than EVA based compounds.
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Selection of the appropriate coupling agent is an important issuefor HFFR compounds:
↓The use of reactive polymers such as LOTADER®, OREVAC®
improves fillers dispersion and adhesion with base polymer.↓
The use of a coupling agents allows to increase the tensile strength at break while keeping a good elongation at break.
↓LOTADER® and OREVAC® allow to reach cables specifications. Example : Mechanical specifications for Euro Tunnel Cable are strength at break >10 Mpa and Elongation >125%.
Why coupling agent?
15
0
2
4
6
8
10
12
14
EVA 2
8 %gr
afte
d
LOTA
DER 32
10
LOTA
DER 42
10
OREVAC
183
02
OREVA
C 930
4
Ten
sile S
tren
gth
(M
Pa)
0
20
40
60
80
100
120
140
160
elo
ng
atio
n a
t bre
ak (%
)
Effect of coupling agent
Tests run on thestandard formulation presented on page 9
Recommendations:
LOTADER® 3210, 4210
OREVAC® 18302
The use of a coupling agents allows to increase the tensile strength at break while keeping a good elongation at break
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Coupling agent Unit Tensile strength
(MPa)
Elongation at break (%)
Lotader 3210 Internalmixer 13 135
Orevac 18302 Internalmixer 12 110
Customer results with Orevac 18302
Buss ortwin
screw 14 195
*:
Choice of LOTADER® versus OREVAC®
LOTADER® 3210: General purpose, versatile coupling agent.
OREVAC® 18302: Better compounding efficiency on twin screw extruders and Buss co-kneaders.
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Ageing HFFR compounds
1211417813.425Lotader3210
155100
12412.522010.811Lotader3210
135100Lotryl 29MA03
13014.717615.225Lotader3210
155100
15014.719014.111Lotader3210
135100Lotryl 24MA005
12015.220014.725Lotader3210
155100
14012.825611.811Lotader3210
135100EVA 280328% VAMI 3
Elongation%
Tensile MPa
Elongation %
TensileMpa
PartsGradePartsPartsGrade
Aging :7days /180°CMechanical Properties
Coupling agentATHPolymer
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Crosslinking
Main reasons for crosslinking
Improved Temperature resistanceImproved drip resistance when burningImproved creep resistance ( deformation under load)
Improved chemical resistance( stress crack)
Improved impact resistanceIncrease abrasion resistance
Example: T3 cable for automotive
Severe chemical environment (oil, lubricants, battery acid)
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Crosslinking technologies
Peroxide (DCP)
Radiation10-15 Mrad
Silanes
SioplasDry silane(Monosil)
Peroxide
Heat
- H2
e-e-
e-
SiOR
OROR Heat Si
OR
RO OR
X 2
WaterCatalyst
Si
SiO
RO
OR
OR
ORPeroxide
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Crosslinking solutions
The compounds using Lotryl® as base polymer and Lotader® orOrevac® coupling agents have been successfully crosslinked by E beam technology, peroxides, silanes.
The selection of appropriate grades should be made according to the technologies used.
Examples:E beam and silane for T3 automotive cablePeroxide and silane for medium and high voltage cable.
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Formulation: LOTRYL® 24MA005 + PE + LOTADER® 3210/OREVAC® 18302 + ATH/MDH
Material selection Temperature requirements
Material selection Material selection Temperature requirementsTemperature requirements
T1T1
T2T2
T3T3
T4T4
T5T5
T6T6
85°C
105°C
125°C
150°C
175°C
200°C
PVCPVCbrominated plasticizer
antimony
PPPPLOTRYLmodified
ETFEETFEPVDFPVDF
FEPFEP
PTFEPTFE
PFAPFApr
ice
perf
orm
ance
TPETPEHFFR
XX--HFFRHFFRLOTRYL®LOTRYL®EVATANE®EVATANE®LOTADER®LOTADER®
OREVAC®OREVAC®
HFFRHFFRLOTRYL®, EVATANE®LOTRYL®, EVATANE®LOTADER®, OREVAC®LOTADER®, OREVAC®
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POWER CABLEMEDIUM AND HIGH VOLTAGE
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1: Copper conductor2: Internal semi conductor:
Based on LOTRYL® 17BA073: Insulation XLDPE -XLLDPE
Using “CLEAN” LOTRYL®
17BA044: External semi conductor
Based on EVATANE® 3325 or 33455: Concentric conductor6 : Copper layer7 : HFFR sheathing :
Evatane®/Lotryl®
1
2
3
4
56
7
Arkema resins inMedium/High Voltage Cable
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Medium/High Voltage Cable
2. Internal semi conductor layerTo eliminate electrical tracking and arcing discharges
Needs good thermal stability as conductor temperature can reach 90°CNeeds good adhesion to conductor and to insulation layerNeeds extremely homogenous dispersion of the carbon filler (40%)Needs to be easy to process, good smoothness (thin layer)Needs to be crosslinked by peroxyde and extruded at low temperature 130°C-140°C
Arkema recommendationsLOTRYL® 17BA07 or 17BA04 for their high polarity, good thermal stability and fluidity.LOTADER 3210 (20% to 30% in dilution in LOTRYL® ) in order to
optimize dispersion with treated carbon filler (coupling agent) and adhesion to conductor.
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3. Insulation Layer:To prevent electrical breakdown
Needs to eliminate water-treeing which results in insulation failure of the cable.Needs to improve environmental stress cracking resistance.
Arkema recommendations
Main products used are crosslinked LLDPE,LDPE or EPDM Adding 15% LOTRYL® 17BA04 or 18MA02 will prevent water treeing and improve stress cracking resistance.
Medium/High Voltage Cable
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4. External Semi conductor:To provide electrical protection
Needs good peelability between external semiconductor (4) and insulation layer (3)
Arkema recommendationsPeroxide crosslinked EVATANE 33-25 or 33-45 based compound with carbon black (40 weight%).
Medium/High Voltage Cable
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7. Sheathing- jacketing:To provide mechanical and thermal protection
Needs good mechanical resistanceNeeds high chemical resistanceNeeds to be flame resistant
Arkema recommendationsMineral filled HFFR compound based on EVATANE® with high VA content 28-03, 28-05 LOTRYL® with high acrylate content ( 30 BA 02, 29MA03)LOTADER ® 3210, OREVAC ® 18302
Medium/High Voltage Cable