Patent ID: 6200399
Filing Date: 2001-03-13
Classification: B29C,B29K,B29L,G02B,Y10T

Abstract:
A method for continuously embossing a precision pattern of micro-prismatic elements on one surface of a continuous resinous sheeting material, the method being performed with the aid of a generally cylindrical metal embossing element having an inner surface and an outer surface, the outer surface having a precision embossing pattern which is the reverse of the precision pattern to be formed on one surface of said sheeting, and wherein the method includes the steps of:(a) continuously moving the embossing element through a heating station where said embossing element is heated to a predetermined temperature and then to a cooling station where said embossing element is cooled below said predetermined temperature;(b) continuously conveying into proximity with said embossing element superimposed resinous film and at least one layer of sheeting material, said resinous materials of said film and said sheeting each having different glass transition temperatures;(c) continuously passing said superimposed resinous film and sheeting between said embossing element and at least one sonic welding head with one surface of said sheeting confronting and engaging said precision pattern of said embossing element to thereby begin to impress said pattern into said sheeting;(d) heating said embossing element to said predetermined temperature at said heating station, said temperature being greater than the glass transition temperature of said sheeting and less than the glass transition temperature of said resinous film;(e) pressing said superimposed film and sheeting against said embossing element at a plurality of pressure points sequentially spaced along said heating station with said one surface of said sheeting confronting and engaging said precision pattern of said embossing element until said one surface of said sheeting fully conforms to said precision embossing pattern; and(f) continuously stripping said superimposed layer of film and embossed sheeting from said embossing element.