Method of heat control in a skin packaging machine

Claim 1

In a skin packaging machine having an oven having heating elements, a horizontal surface below said oven to which vacuum is applied, a film receiving frame between said oven and surface, means for raising and lowering said frame, a film supply adjacent said frame, and a power supply connected to said heating elements, the method of operating said skin packaging machine comprising the steps of, pulling film onto said frame, raising said frame to a position adjacent said oven, placing a substrate and object on said surface, lowering said frame to place said film on said substrate and object, and applying power to said heating elements as follows: applying full power to said heating elements to heat said film for a first interval of time immediately prior to lowering said frame, applying low power to said heating elements before pulling said film onto said substrate for a second interval of time extending to the beginning of said first interval of time, said low power being applied by switching power on and off during respective duty cycles.