Post on 01-Apr-2018
Author: Hubert Oggermüller Approval: May 2008
VM / Dr. Alexander Risch _____________________
Non-black Fillers
in EPDM Extrusion
Formulation
(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
VM
-4/0
5.2
00
8/0
61
10
98
0
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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
Filler 250/110/75
Diethylene glycol (DEG), as indicated 0/3/5
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
Loading: 75 phr
110 phr 110 phr 250 phr
Open Mill Batch Temperature Time of mixing
150 x 300 mm 500 cm³
50 °C 15 to 20 min
Extruder Temperature of barrel Temperature of head
d = 30 mm L/D = 15
70 °C 110 °C
Applied in this test compound:
(1) Vistalon 7500 , Exxon (2) Zinkoxyd aktiv, Bayer (3) Kezadol GR, Kettlitz (4) Sunpar 2280, Sun Oil Company (5) TAC 50 %, Kettlitz (6) Perkadox 14/40, Akzo
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Contents
Index of Compound Costs Page 4
Properties of Raw Compound
Mooney Viscosity ML (1+4) at 120 °C Page 5 Mooney Scorch t5 (ML) at 120 °C Page 6 Extrudability (Quality), Rating Garvey-Profile Page 7 Extrudability (Quality), Torque of Extruder Page 8 Extrudability (Quantity), Maximum of Extrusion Speed Page 9 Extrudability (Quantity), Torque of Extruder Page 10 Rotorless Cure Meter, t5 at 180 °C Page 11 Rotorless Cure Meter, t90 at 180 °C Page 12
Properties of Vulcanizate
Tensile Strength Page 13 Elongation at Break Page 14 Modulus Page 15 Hardness Page 16 Tear Resistance Page 17 Rebound Elasticity Page 18 Abrasion Page 19 Compression Set Page 20
Properties after Air Ageing
Change of Tensile Strength Page 21 Change of Elongation at Break Page 22 Change of Hardness Page 23 Change of Tear Resistance Page 24
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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