Patents Assigned to S&W Plastics, Inc.
  • Patent number: 5312844
    Abstract: A method of producing injection molded in-line skate wheels is disclosed. The method includes heating an injection molding unit suitable for injecting molten polyurethane, placing a thermoplastic polyether type polyurethane into the unit and heating the polyurethane until it is molten or at about 380.degree. to about 460.degree. F. A polyurethane hub is placed in a mold whereby the mold and hub are of shapes and sizes suitable for producing in-line skate wheels. The hub-containing mold is heated to about 50.degree. to about 100.degree. F. in order to prevent the molten polyurethane from prematurely hardening. Once the mold is heated, about 46 to about 50 g of polyurethane is injected into the mold at about 75 to about 100 psi. The polyurethane is cooled to about 120.degree. to about 130.degree. F. to allow the polyurethane to harden and the resulting wheel is removed from the mold.
    Type: Grant
    Filed: May 14, 1993
    Date of Patent: May 17, 1994
    Assignee: S&W Plastics, Inc.
    Inventors: Stanley W. Gonsior, Dennis L. Hvam