Process for forming laminated paperboard containers

Abstract

Tearing, blistering, delamination and other defects in deep drawn plastic laminated paperboard containers are eliminated by adding controlled amounts of warmed moisture to the paperboard immediately prior to forming thereof. Water is heated to a desired temperature and is applied by in-line processing equipment to the unlaminated side of the paperboard which functions to both soften and paperboard and preheat the laminate. By heating both the male and female parts of a die press employed for forming the preheated, softened laminate into the container, preheating the laminate using warm water prior to forming and, continuously controlling the moisture added to the paperboard, the degree of stress imposed on the plastic layer of the laminate and the resulting defects in the formed container are significantly reduced.

Dependencies are inferred from the claim text.