Patent ID: 6024907
Filing Date: 2000-02-15
Classification: B29C,B29K

Abstract:
A method for the surface finishing of a film or sheet in a softened state, comprising the steps of:a) passing an endless belt comprising a shape memory alloy through a nip of two cooperating rolls, wherein the endless belt is at a temperature above the temperature transition range of the alloy;b) passing the film or sheet through the nip such that a face of the film or sheet makes contact with a finished face of the belt;c) applying pressure to the nip such that the face of the belt is pressed into the face of the film or sheet, thereby forming a finish on the film or sheet face;d) cooling the belt and film or sheet to a temperature below the temperature transition range of the alloy, which increases alloy volume thereby allowing easy release of the film or sheet from the belt;e) releasing the film or sheet from the belt, wherein the finished film or sheet face mimics the belt face;f) reheating the belt to a temperature above the temperature transition range of the alloy after the film or sheet is released from the belt, but before the film or sheet makes contact with the belt at the nip, thereby decreasing alloy volume; andg) keeping the belt under tension by a shock absorbing means which dissipates shock induced to the endless belt as the endless belt is heated above and cooled below the temperature transition range of the alloy.