Excuse me for this question but im beginner in polymer . what is the difference between this two . As i knowledge the EPDM (Ethylene Propylene Diene Monomer ) is a rubber but as why it is on the plastic category also?
Sorry, I didn't read your post well enough. I looked on my SW material database and see that is listed in two places as well. The supplied SW material database does not list many physical properties for either. I notice that the EPDM in the plastic section has a significant lower density and no tensile property while the EPDM listed in the Rubber section specifically says that it has been compounded to achieve a 60 durometer and has a higher density and also a tensile strength listed.
I notice also that the color of the EPDM in the plastic section is white which is unusual but not impossible for compounded rubber. Perhaps the SW Plastic EPDM material is the actual uncured EPDM resin which is purchased from the petro company for customers to mixed with fillers, additives, and curatives to form the final rubber compound which is vulcanized (thermoset) into the desired finished products.
Though I cannot imagine what use an unvulcanized product would be in the context of assigning it to a SW part. Who knows how SW initially seeded their material database. Neither of the EPDM materials have much information to be useful to the end user.
Plastics is a generic term for organic materials or compounds that can be molded into shape. They can be either naturally occurring compounds derived from plants and animals or completely synthetically produced through chemistry generally from petrochemical reactions.
Plastics can be divided into two categories: thermoplastics which when heated becomes soft and viscous can be molded into shape and then cooled to harden/solidify it and maintain the molded shape. Thermoplastics can be reheated to a softened state and molded multiple times over and thus are easier to recycle. Thermoplastics can be manufactured with a variety of physical properties from rock hard to soft and pliable.
A second type of plastic is a thermoset plastic which can be heated to a soft and viscous state be molded into shape, however during the heating process, often extended, initiates a chemical reaction within the material causing it to take a set in the molded shape permanently. Further heating will not cause a thermoset plastic to again soften or become pliable, Recycling of these "set" materials require further mechanical or chemical breakdown in order to recycle. Thermoset plastics like their brothers thermoplastics can be manufactured with a variety physical properties like the very first synthetic plastic Bakelite which is hard and rigid to something like EPDM rubber which remains flexible and pliable in its fully set state.
Plastics is a very broad range of materials as evidenced by exploring even the abridged material database provided with Solidworks
Tanks very much .
But i mean why the EPDM is categorized in two kind of material (Plastic & Rubber ) . Is it possible that one substance has two category ?
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