초록 ▼

A coated paperboard product and a process for producing the same which includes corona discharge treatment of a paperboard surface and subsequent extrusion of molten polyester thereon. The resulting product has a very high degree of adhesion between the paperboard and polyester layers, and is capabl

A coated paperboard product and a process for producing the same which includes corona discharge treatment of a paperboard surface and subsequent extrusion of molten polyester thereon. The resulting product has a very high degree of adhesion between the paperboard and polyester layers, and is capable of being utilized for forming pressed food trays which can be subjected to oven cooking temperatures.

대표청구항 ▼

A process for producing coated paperboard material suitable for forming pressed heatable food trays, comprising the steps of: (a) passing a web of paperboard material through a corona discharge device at a corona energy density level sufficient to subject the paperboard to an energy density of at le

A process for producing coated paperboard material suitable for forming pressed heatable food trays, comprising the steps of: (a) passing a web of paperboard material through a corona discharge device at a corona energy density level sufficient to subject the paperboard to an energy density of at least 0.35 joules per square inch of paperboard surface; (b) passing the corona treated paperboard into a nip formed between a chill roll and a backup roll while simultaneously passing a hot melt extrusion of polyethylene terephthalate into the nip between the corona treated side of the paperboard and the chill roll, the hot melt extrusion exiting from the extrusion die at an initial temperature of between 580°F. and 640°F. through an air gap before insertion into the nip, the air gap distance being selected with respect to the speed of the paperboard and the ambient and chill roll temperatures such that the temperature of the extrusion at the time of contact with said paperboard is above its melting temperature and such that it is chilled below its glass transition temperature at the time that it leaves the chill roll to thereby facilitate separation therefrom.