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May 21, 2021 2021
Selection of compounding agent for continuous vulcanized EPDM rubber extrudate

EPDM rubber adhesives are weather resistant, age resistant, ozone resistant, and can be used to produce a variety of models or extruded rubber products. EPDM is suitable for continuous vulcanization, especially for extruded rubber products. Continuous curing process includes microwave curing, salt bath curing, Shear head and hot air curing, etc. . What are the selection techniques for EPDM rubber using continuous curing process?


EPDM compound requires stable properties, fast curing speed, fast extrusion speed, stable size, good collapse resistance, good appearance quality, good compactness, good physical and mechanical properties.


Curing System Selection


In order to improve the curing speed of epdm compound and adapt to the requirement of continuous curing, sulfur is generally chosen as curing agent, combined with a variety of accelerators. DITHIOCARBAMATES and Tyuram type accelerators and thiazole type accelerators have a good synergistic effect when they are used together. Commonly used accelerants are PZ/TMTD/M/D/CZ and so on.


The vulcanization system not only needs fast vulcanization speed, but also needs good vulcanization flatness to ensure that there is no undervulcanization and reversion during vulcanization. Peroxide HY19S4J2Y-MXF and other curing systems can be used for continuous curing in salt bath.


Reinforcement system

Filling agent can choose suitable mineral Filler, such as heavy calcium carbonate, light calcium carbonate, TALC, clay and so on. In the sealing strip products, in order to ensure a certain reinforcement effect and appearance quality, generally choose the active treatment, superfine products are better.


For continuous vulcanized EPDM extrusion products, the filler in the compound should be chosen to fill a large amount of carbon black, semi-reinforced carbon black, general carbon black, etc. . The fine particle carbon black with high reinforcing property, such as N330/N220, should be used as little as possible to avoid too high viscosity of rubber compound. In EPDM rubber sealing strip products, silica and other silicate fillers as little as possible, so as to avoid the formation of pores.

Softening system


Plasticizers to choose and EPDM rubber compatibility, not easy to spray, can be added in large quantities, to be suitable for high temperature rapid curing, and the price should be moderate. General EPDM rubber compound selection of operating oil, paraffin oil, naphthenic oil, aromatic oil and so on. Paraffin oil polymer glue has good heat and cold resistance, resilience to flexure performance, color stability, easy to use peroxide curing.


Rubber products manufacturers producing extruded products, EPDM rubber should be based on the choice of vulcanization methods, rational selection of the mixture, rational use of arrangements. The vulcanization rate and foaming rate should be coordinated in the production of EPDM sponge seal.