Continuous vulcanization unit

The cost of processing TPEs can be significantly less than that for conventional thermoset rubber. No vulcanization is needed. For example, no million-dollar continuous vulcanization unit is necessary for weather-stripping extrusion. Molding cycles are much shorter since all that is necessary is to cool the molten article below its hardening temperature. 

Rubber weatherstripping for automotive exteriors is usually produced from compounds based on EPDM. These weatherstrips can be dense (no voids), cellular (closed cell structure), or semidense. Weatherstripping is commonly extruded and cured in a continuous vulcanization unit (CVU). Some new production lines are switching over to thermopiastic elastomers (TPEs), which eliminate the curing step, with a reduction in production costs. 

Rubber bands (sometimes also called elastic bands, lackey bands, or gum-bands) are manufactured by slicing with heat along the width of an extruded rubber tube on a mandrel. Therefore a rubber band is actually produced from slices of a cured rubber tube. Usually, rubber bands are made from rubber compounds based on natural rubber. Rubber-band tubes are commonly cured in a continuous vulcanization unit. 

Because of the different vulcanization chemistry involved in each commercial ACM, a vulcanization system specific to the cure site present has to be adopted. Many cure systems for labile chlorine containing ACM have been proposed (45). Among these the alkali metal carboxylate—sulfur cure system, or soap—sulfur as it is called in the United States, became the mainstay of acryflc elastomer technology in the early 1960s (46), and continues to be widely used. 

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