초록 ▼

Methods and apparatus are provided for producing seamless or apparently seamless plastic foam cups formed from both seamless and seamed sidewall blanks formed by stretching initially cylindrical blank into frusto-conical shapes and then molding such blanks with either expandable foamed plastic beads

Methods and apparatus are provided for producing seamless or apparently seamless plastic foam cups formed from both seamless and seamed sidewall blanks formed by stretching initially cylindrical blank into frusto-conical shapes and then molding such blanks with either expandable foamed plastic beads or foam plastic discs to form an integral cup bottom with the sidewall in an apparently seamless structure. If cylindrical containers are desired, or if frusto-conical sidewall blanks are utilized no stretching is required. Presizing of sidewall thickness prior to treatment in the mold is also provided.

대표청구항 ▼

The method of forming a smooth-sided foam plastic container from a expandable foam plastic cylinder comprising the steps of: placing said expandable foam cylinder on a mandrel and heating said cylinder to a desired temperature over a desired interval to initially size the wall thickness thereof; rem

The method of forming a smooth-sided foam plastic container from a expandable foam plastic cylinder comprising the steps of: placing said expandable foam cylinder on a mandrel and heating said cylinder to a desired temperature over a desired interval to initially size the wall thickness thereof; removing said cylinder from said mandrel and inserting same in the mold cavity of a steam heated expandable foam plastic bead container mold of a substantially conformal interior shape; injecting expandable foam plastic beads into one end of said mold; and heating said mold to cause said beads to expand and mutually fuse with themselves and one edge of said cylinder to form a container bottom which is seamlessly integrated with said cylinder to provide a seamless foam container.