Author:
Approval:
Hubert Oggermüller
May 2008
VM / Dr. Alexander Risch
_____________________
Non-black Fillers
in EPDM Extrusion
Formulation
VM-4/05.2008/06110980
(peroxide cured)
HOFFMANN MINERAL GmbH • P.O. Box 14 60 • D-86619 Neuburg (Donau) • Phone (+49-84 31) 53-0 • Fax (+49-84 31) 53-3 30
Internet: www.hoffmann-mineral.com • e-Mail: info@hoffmann-mineral.com
Summary
Two classes of filler are suitable for extrusion processing, particularly
when special profiles must be produced. The products based on Neuburg
Siliceous Earth and calcined clay produced the best extrusion properties
among the non-black fillers tested. Neuburg Siliceous Earth has a clear
advantage here in terms of price to performance ratio. Surface-treated
AKTISIL VM 56 wins on cost compared to untreated calcined clay, at the
same time providing better tensile strength, a higher modulus and a lower
change of elongation at break after ageing.
Where emphasis is placed on mechanical properties, combining the
active filler with carbon black or precipitated silica (or silicates in the case
of non-black applications) is a solution. Here the recipe must be adapted
to fit the specific needs involved.
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Non-black Fillers
in EPDM Extrusion Formulation
(peroxide cured)
Test Compound
EPDM, 55 % Ethylene, medium diene-content
ML (1+8) 125 °C, approx. 821
100
Zinc oxide2
5
Stearic acid
2
Calcium oxide coated by special dispersion agents 80 %³
10
250/110/75
Filler
0/3/5
Diethylene glycol (DEG), as indicated
Paraffinic oil4
60
Triallyl-cyanurate 50 %5
3
Bis(t-butylperoxy-isopropyl)benzene 40 %6
8
Regarding precipitated silica and the
different types of precipitated silicate
additional compounds with 3 phr DEG were
examined. To obtain an adequate cross
linking the various hard clays need the use
of 5 phr DEG.
Curing was carried out in a press at 180 °C.
The curing time was t90 + 10 %.
Please mind! The following figures show
trend analysis, which only can be the basis
for specific problems solving.
Filler:
Precipitated Silica
Precipitated Silicates
Carbon Black
All others
Open Mill
Batch
Temperature
Time of mixing
Extruder
Temperature of barrel
Temperature of head
Applied in this test compound:
(1)
(2)
(3)
(4)
(5)
(6)
Vistalon 7500 , Exxon
Zinkoxyd aktiv, Bayer
Kezadol GR, Kettlitz
Sunpar 2280, Sun Oil Company
TAC 50 %, Kettlitz
Perkadox 14/40, Akzo
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Loading:
75 phr
110 phr
110 phr
250 phr
150 x 300 mm
500 cm³
50 °C
15 to 20 min
d = 30 mm
L/D = 15
70 °C
110 °C
Contents
Index of Compound Costs
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Properties of Raw Compound
Mooney Viscosity ML (1+4) at 120 °C
Mooney Scorch t5 (ML) at 120 °C
Extrudability (Quality), Rating Garvey-Profile
Extrudability (Quality), Torque of Extruder
Extrudability (Quantity), Maximum of Extrusion Speed
Extrudability (Quantity), Torque of Extruder
Rotorless Cure Meter, t5 at 180 °C
Rotorless Cure Meter, t90 at 180 °C
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Properties of Vulcanizate
Tensile Strength
Elongation at Break
Modulus
Hardness
Tear Resistance
Rebound Elasticity
Abrasion
Compression Set
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Properties after Air Ageing
Change of Tensile Strength
Change of Elongation at Break
Change of Hardness
Change of Tear Resistance
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Annex
Pictures of extrusion profiles
Page 25-27
Our technical service suggestions and the information contained in this report are based on experience
and are made to the best of our knowledge and belief, but must nevertheless be regarded as non-binding
advice subject to no guarantee. Working and employment conditions over which we have no control
exclude any damage claims arising from the use of our data and recommendations. Furthermore, we
cannot assume any responsibility for any patent infringements which might result from the use of our
information.
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Annex:
Extrusion Profiles
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