METHOD AND APPARATUS FOR CREATING A SUBSTANTIAL UNIFORM TEMPERATURE ACROSS A PLASTIC SHEET FOR DELIVERY TO AN APPLIANCE LINER THERMOFORMING DEVICE

摘要

A sheet of plastic to be thermoformed into aappliance liner is brought to a substantially uniformtemperature, preferably to a temperature differentialof less than 5 degrees F throughout, by directing afluid medium upon opposing side surfaces of the sheet.In the most preferred form of the invention, the fluidmedium is constituted by air which is heated, impingedupon the opposing surfaces and recirculated, with thetemperature and flow rate of the air being controlledbased on sensed operating parameters.