Patent ID: 6951336
Filing Date: 2005-10-04
Classification: B29C,B29K,B29L,F16C,F16J

Abstract:
1. A process for making a boot seal comprising the steps of: (a) obtaining two plastics, at least one being a polyester resin; (b) feeding said plastics separately into an extruder die; (c) separately extruding said plastics from said extruder die as coaxial tubular molten streams, into a mold cavity having a corrugated inner wall; (d) vacuum expanding the coaxial tubular molten streams against said mold cavity inner wall; (e) cooling the molten streams while vacuum held against the mold cavity inner wall; and (f) stretching said polyester resin to cause a molecular orientation for increasing the strength of said polyester resin, said polyester resin, when cooled, being stretch toughened to have a percent elongation to rupture of at least 100 and a flexural modulus less than 100,000 psi.