Marbling plastic sheet

Claim 1

METHOD OF PRODUCING PLASTIC SHEET HAVING A MARBLED APPEARANCE, IN A CALENDER HAVING A BAFFLE BETWEEN THE TOP ROLL AND THE OFFSET ROLL, WHICH COMPRISES CONTINUOUSLY FEEDING HOT GRANULES OF BASE PLASTIC MATERIAL BETWEEN THE TOP ROLL AND THE BAFFLE. SIMULTANEOUSLY CONTINUOUSLY FEEDING COLD SLIVERS OF COLORED PLASTIC MATERIAL BETWEEN THE OFFSET ROLL AND THE BAFFLE IN SUBSTANTIALLY ALIGNED RELATION TRANSVERSE TO THE DIRECTION OF CALENDERING WHEREBY THE COLORED PLASTIC MATERIAL IS EMBEDDED IN THE BASE PLASTIC MATERIAL AND FORMED INTO A LONGITUDINALLY CONTINUOUS INTERMEDIATE SHEET, PASSING SAID INTERMEDIATE SHEET ON THE TOP ROLL CONTINUOUSLY IN ITS LONGITUDINAL DIRECTION AT CALENDERING SPEED TO A PARALLEL ROLL THEREBELOW, AND CONTROLLING THE TEMPERATURE ON SAID TOP ROLL WITH RESPECT TO THE CALENDERING SPEED TO FORM A BANK WHEREIN THE ONCOMING SHEET ON THE TOP ROLL ENCOUNTERS THE BANK AT THE BITE BETWEEN THE TOP ROLL AND THE ROLL THERERBELOW, DOUBLES OVER AND RETURNS TO SAID BITE IN MULTIPLE THICKNESSES OF SUPERIMPOSED FOLDS.