Rubber Extrusion Equipment
Rubber processing requires specialized knowledge and custom extrusion equipment that has been specifically designed to handle the very elastic properties of rubber compounds.
Properties of Rubber
Both natural and synthetic rubbers are most useful for their high elasticity as well as being very resistant to water and moderate chemicals.
Types of rubber that are suitable for rubber extrusion include:
- Ethylene Propylene (known as EPR or EPDM)
- Styrene-butadiene rubber (SBR)
Different grades of rubber are available in commercial and specific grades including MIL, ASTM and SAE.
It is possible to extrude rubber into shapes and profiles of uniform cross section, though they often require curing or vulcanization to harden the final product.
In preparation for extrusion, additives like sulphur, carbon black and accelerators may be added to the rubber to form a compound. This compound dough is then milled into sheets or pellets ready for processing.
The elastic qualities of rubber compounds makes rubber processing machinery design critical, specifically extruder and extrusion die design, since shrinkage occurs throughout the extrusion process and even after molding, due to die swell. This shrinkage is not uniform along the length of a rubber extrusion, hence specialized design is necessary, as well as extensive testing of material behavior to ensure all tolerances are met for the finished extruded rubber product.
- extruded rubber seals
- loading dock bumpers
- stretch bands