Patents Assigned to Plasti-Pak
  • Patent number: 4467052
    Abstract: A plastic tray for packaging food products is disclosed. The tray has a preferred composition of about 85 percent polypropylene, 15 percent impact modifier or copolymer, 1 percent nucleating agent, and 1 percent density reduction agents.A method of manufacturing a plastic tray of packaging food products is disclosed. The method includes the steps of mixing the polypropylene, impact modifier, nucleating agent and density reduction agents together, heating the mixture at 450.degree. F. to 550.degree. F. under a pressure of about 300 p.s.i., injecting the heated mixture into a mold, and cooling the mixture.
    Type: Grant
    Filed: March 18, 1982
    Date of Patent: August 21, 1984
    Assignee: Plasti-Pak
    Inventors: Robert Barnwell, David R. Frye