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Belgian Plastics and Rubber
InstituteAdditives and Processing Aids
forPolymersConference in cooperation with BPG
Oktober 22th 2008, Auberge du Pecheur ,
Sint Martens-Latem (Gent)
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StruktolStruktol ProcessProcess AdditivesAdditives
InjectionInjection MouldingMoulding ofofrubberrubbercompoundscompounds
ImprovmentsImprovmentsbyby usingusing additivesadditives
PROCESSING AIDS FOR POLYMERSPROCESSING AIDS FOR POLYMERS
Schill + SeilacherSchill + Seilacher StruktolStruktol AktiengesellschaftAktiengesellschaftPeter Kosczinsky 644
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3
Contents
1. Production Processes Compounds and Requirements
2. Processing Additives Introduction + Function
3. How to choose the right Process Additive4. Example Case Studies problems and their solution
5. Conclusion
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Injection Moulding Compounds
Requirements
Must have high level of dispersion
Need to have excellent flow properties
A fast cure rate is required
Must release easily from the mould
Should be low in mould fouling
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Injection Moulding
High precision
components
Seals, O rings,
Gaskets and bellows,
Metal bonded parts
Rubber compounds
must be well mixed
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Injection Moulding
Highly automated
process
Short production cycles
are used
Robotised demoulding
High uniformity of
produced parts
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2. Production Process in the Rubber Industry
What can be influenced by process addit ives?
Raw
Materials RubberCompound
Finalrubber
article
CompoundingCompounding ProcessingProcessing
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2.1 Function of ProcessAdditives
Compounding stage
Raw
MaterialsRubber
CompoundFinal
rubber
article
CompoundingCompounding ProcessingProcessing
Viscosity reduction
Easier mixing release
Better batch homogenity
Shorter cycles, more
efficient mixing
Better fil ler dispersion
F t P
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Raw
MaterialsRubber
CompoundFinal
rubberarticle
CompoundingCompounding ProcessingProcessing
. Functon o ProcessAdditives
Processing stage
Improved compound flow
Reduced compound st ickiness
Better demoulding / Less foul ing
Improved article appearance
Higher productivity
L t
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3. The Choice of Additive
Problem?!
Suited, most efficient
process additive is
choosen
Know-How
Experience
Type of polymerused / blend ?
Formulation analysis:filler dosage?
curingsystem?plasticiser type?
stearic acid level?etc.
Appearance ofrubber part ?
Whatproductionprocess ?
Problem Details?
Other details:Mooney viscosity,ShA, rubber-metal
bonding, automotive?etc
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4. Example Case Studies
4.1 Injection Moulding of EPDM
Formulation : 3907.5 Compound 1 Compound 2
Vistalon 3666 175 175
N-550 Statex 95 95
Sunpar 2280 10 10
ZnO 10 10
Vulkanox HS/LG 1 1
Vulkanox MB2/MG-C 1 1
Struktol WS 180 (flakes) 2
Perkadox 14-40 8 8
Sartomer 206 2,5 2,5
Sum : 302,5 304,5
Occuring Problems:
a) insufficient compound flow
b) stickiness of parts to mouldsurface
c) quick mould foul ing
Process Additive
Struktol WS 180
- Process lubricant(organosilicone based)
- efficient at lowdosage 0,5 - 2 phr
- well compatiblewith EPDM
(lowperoxide demand)
- pelletised product
- suited forautomotivesector
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4.1 Injection moulding of EPDM(Compound1 + Compound 2)
a) Influence of compound flowTrial procedure
Injection Spider MouldArburg Injection Machine
Compound 1 (control) andCompound 2 (Struktol WS 180)
injected 30 cycles
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4.1 Injection moulding of EPDM(Compound1 + Compound 2)
a) Influence of compound flowThe Result
Compound 1:Control spider
Compound 2:Spider incl. Struktol WS 180
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4.1 Injection moulding of EPDM(Compound1 + Compound 2)
c) Reduction of mould fouling levelTrial Procedure
Compound 1 + Compound 2:injected 30 cycles each
Mould cleaning: Struktol MC-Imould cleaning compound
injected after Compound 1 andCompound 2 cycles
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4.1 Injection moulding of EPDM(Compound1 + Compound 2)
c) Reduction of mould fouling levelA Rating Scheme how to judge dirt level in the mould
Areas A E arerated with notes
(front- and backside):
Dirt Level Note
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4.1 Injection moulding of EPDM(Compound1 + Compound 2)
c) Reduction of mould fouling levelThe Result
DirtLevel caused byCompound 1 (control)
DirtLevel caused byCompound 2 (Struktol WS
180)
Note: 6Note: 8
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5. Example Case Studies
5.2 Injection of AEM (Vamac)Mischung 3828.4 Compound 1 Compound 2Vamac HGV 50 50
Vamac G 50 50Russ N-772 70 70
Struktol KW 759 5 5Naugard 445 2 2
Armeen 18D 0,5 0,5
Stearinsure 2Struktol WB 222 2
Vulcofac HDC 1,25 1,25Ekaland DPG 4 4
Summe 184,75 184,25
Occuring Problems:
a) insufficient compound flow
b) stickiness of parts to mouldsurface
c) mould fouling
Process Additive
Struktol WB 222
Process lubricant
(fattyacid / esterbased)
- Dosage 11,0 - 3,0 phr
- well compatible withAEM
- Mikro Beads
- suited for automotivesector
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5.1 Injection moulding of AEM(Compound 1 + Compound 2)
a) Influence of compound flow
The Result
Compound 1
Armeen 18D +
Stearic Acid
Mischung 2
Armeen 18D +
WB 222
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Compound 1 + Compound 2
Injection with 40 cycles each
Mould cleaning: Struktol MC-I
mould cleaning compoundinjected after compound 1 +
compound 2 cycles
Trial procedure
5.2 Injection moulding of AEM(Compound 1 + Compound 2)
a) Influence of mould fouling
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5.2 Injection moulding of AEM(Compound 1 + Compound 2)
a) Influence of mould fouling
The result
Dirt level caused by
compound 1 - control
(Armeen 18D + Stearic Acid)
Dirt level caused by
Compound 2
(Armeen 18D + WB 222)
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Semi-permanent Release AgentsStruktol Permalease 90
Instant curing
Can be used at low mould temperatures(130C)
Water based Reduction of mould fouling
Good surface finish
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MouldMould SurfaceSurface ModificationModification
AFM microscope view of coated steel plate in frictionAFM microscope view of coated steel plate in friction
modemode
Permalease
coated
uncoated
Friction Modus
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Influence of mould fouling(Injection moulding of AEM compounds)
Compound1 + Compound 2
Trial procedure
Spider Mould Arburg Injectionmoulding Mould coating with Struktol
Permalease 90
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Influence of mould foulingResult: Injection moulding of AEM
coated + uncoated mould.
Dirt level after 40 cycles
with a uncoated mould
Dirt level after 40 cycles
with a coated mould
Compound 1 (Armeen 18D / Stearinsure)
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Influence of mould foulingResult: Injection moulding of AEM
coated + uncoated mould
Dirt level after 40 cycleswith a uncoated mould
Dirt level after 40 cycleswith Permalease 90
coated mould
Compound 2 (Armeen 18D / WB222)
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5. Conclusion
It is important to choose the best suitedprocess additive for concerned process /occured problem
UseUse ofoflittlelittle processprocess additiveadditive helpshelps toto solvesolve
productionproduction problemsproblems in anin an easyeasy wayway
InjectionInjection mouldingmoulding problemsproblems cancan bebe resolvedresolved byby
usingusing e.ge.g.. StruktolStruktol WS 180WS 180 oror StruktolStruktol WB 222WB 222 ((betterbetter
flowflow,, lowerlower mouldmould foulingfouling,, improvedimproved articlearticle appearanceappearance))
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Struktol HT Products
A new range of products developed to offeraddedadvantages
Several products have improved dispersing nature
Easier dispersibility at lower temperatures Can be mixed into soft compounds or at end of mixing
EF 44HT 266
A86HT 105
WB 16HT 204
A 50PHT 202
Standard ProductHT Product
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Better / faster dispersion of HTvariant compared to standard
process additive grades
Better / faster dispersion of HTBetter / faster dispersion of HT
variant compared to standardvariant compared to standard
process additive gradesprocess additive grades
HT Product offers
improved safety for use insoft compounds or low
viscosity compounds whenadded at the end of mixing
or in mill mixing.
HT product will disperse at
temperatures above 60C
HT Product offersHT Product offers
improved safety for use inimproved safety for use insoft compounds or lowsoft compounds or low
viscosity compounds whenviscosity compounds when
added at the end of mixingadded at the end of mixing
or in mill mixing.or in mill mixing.
HT product will disperse atHT product will disperse at
temperatures above 60temperatures above 60CC
ResultImproved flexibility
Improved safety
Improved performance
ResultResultImproved flexibilityImproved flexibility
Improved safetyImproved safety
Improved performanceImproved performance
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HT 204WB 16
BeadsWB 16 FlControlIngredient
0.50.50.50.5Sulphur
1111CBS
1111DOTG
3Struktol HT 204
3Struktol WB 16 Microb.
3Struktol WB 16 Flake8888Struktol Zimag 29/43
30303030Struktol KW 400
35353535N-990
1111AFD
2222ODPA
100100100100CR (Type W)
Single stage mixing in laboratory Banbury.
Process additives added late after 245 together withcuratives
Dump at 3 30
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MDR 2000
180 C
0
1
2
3
4
5
6
7
0 5 10 15 20 25 30
time (min)
torque(d
Nm)
0
1
2
3
4
5
6
7
0 60 120 180
time ( sec )
power (kW)
Control WB 16 Fl WB 16 HT 204 --
Mixing energy is reduced due topresence of WB 16 types.
Rotor slippage occurs due toinsufficient WB 16 dispersion.
Low temperature generation
Mixing energy is reduced due topresence of WB 16 types.
Rotor slippage occurs due toinsufficient WB 16 dispersion.
Low temperature generation
Cure curves show reduced maxtorque with WB 16 variants.
Probably this is due to rotorslippage as undispersed WB 16
melts at 180C during curing
Cure curves show reduced maxtorque with WB 16 variants.
Probably this is due to rotorslippage as undispersed WB 16
melts at 180C during curing
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Rheological behaviour:
0,030,040,040,03tan delta (MH)
7,888,97,6tc 90%
1,31,41,41,3tc 10%
65,55,56,1torque MH (d/N/m)
0,20,20,20,2torque ML (d/Nm)
180C/30180C/30180C/30180/30Rheometer MDR 2000
1210713Mooney viscosity (1+4)
65555673Sample temperature (C)
408339339478energy consumption (kj)
53515359dump temperature (C)
HT 204WB 16
Beads
WB 16 FlControl
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Physical properties:
2,22,32,52,2Modulus 300% (MPa)
0,60,60,60,6Modulus 100 % (MPa)
745669588759elongation at break (%)
12,310,57,312,7tensile strength (MPa)
Tensile test
31313131Shore hardness
30303030cure time for 6 mm (min) 180C
30303030Cure time for 2 mm (min) 180C
HT 204WB 16
Beads
WB 16 FlControl
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Control WB 16 Microbead
WB16 Flakes HT 204(Microbead)
Microscope images of cut surfaces of vulcanisates
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Tensile Strength
0
2
4
6
8
10
12
14
M Pa
C ontrol WB 16 Flake WB 16
M icrobead
HT 204
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Conclusion
In a soft / low temperature mixing
compound for injection moulding
Struktol WB 16 flake did not disperse
Struktol WB 16 microbead was borderline
Struktol HT 204 was fully OK
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101010Silica (VN3)
HT 204 lateHT 204 earlyControlIngredient
0.50.50.5Sulphur
111CBS
111DOTG
3Struktol HT 204 (added late)
3Struktol HT 204 (added early)
888Struktol Zimag 29/43
101010Struktol KW 400
303030N-220
111AFD
222ODPA
100100100CR (Type W)
Single stage mixing in laboratory Banbury.
HT 204 added early after 30 seconds together with silica
HT 204 added late after 230- together with curatives
Dump at 3 30
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Spider Mouldings
ControlControl Struktol HTStruktol HT
204 added204 addedearlyearly
Struktol HTStruktol HT
204 added late204 added late
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Conclusion
The point of addition has an influence
Late addition resulted in increased flowproperties for the same loading
Struktol HT 204 dispersed OKwhenadded late in mixing
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Thank you for your attentionThank you for your attentionThank you for your attention
For more info: www.struktol.deFor more info: www.struktol.deFor more info: www.struktol.de
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