METHOD AND APPARATUS FOR MANUFACTURING FOAM PLASTIC CONTAINERS BY USE OF A TUBULAR FORMING MANDREL

摘要

The present invention is directed to an apparatus and method wherein preprinted rectangular blanks (10A) of longitudinally stretch-oriented foam sheet material are continuously formed into cylinders by a tubular forming mandrel(M) on which the blanks are folded, seamed and thereafter transferred onto final forming mandrels (FM). Subsequently, the blanks and the final mandrels are heated to shrink the blanks so that they assume the shape of the final forming mandrels. In forming containers, means are provided to place bottom blanks on the product mandrels prior to the loading of the cylinders thereon so as to shrink the cylinders to sidewall shapes overlying the bottom blanks. The top curl on containers such as drinking cups and food tubs is formed after shrink forming. Further, the bottom seam of the container may be reinforced by ironing after shrink forming. The bottom blanks are synchronously-fed to the product mandrels at a compatible spacing and velocity after being initially blanked from a web at a different spacing and velocity achieving a minimum amount of scrap in the web.