Patents Assigned to Duraplast Corporation
  • Patent number: 5238633
    Abstract: The present invention relates to a method and apparatus for forming an extruded plastic lumbar product from a commingled plastic waste feed stock. The apparatus generally includes an extruder portion and a forming portion. The extruder portion includes a compound extruder which compresses and melts the waste product by a sudden transition within a constant pitch conveyor. From the compound extruder, the melt is introduced into a hot melt extruder which is formed so as to prevent vortex of the melt or mixing of the different resins. The hot melt conveyor includes a diminishing pitch along its length and a short transition section and metering section. The hot melt is then formed into a desired profile through a cross-head die in which a series of rovings are introduced into the melt. The rovings serve as a reinforcement for the extruded product as well as define the extruded profile feed rate.
    Type: Grant
    Filed: May 24, 1991
    Date of Patent: August 24, 1993
    Assignee: Duraplast Corporation
    Inventor: Gary L. Jameson