Process for producing polymeric film
AssigneeAgfa-Gevaert
InventorsJan Baptist Van Cappellen, Walter Johannes Rens
Life of this patent
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Abstract
Polymeric film is stretched by pulling the film over a first roller which is heated and over a second roller which is cooled, the second roller rotating at a greater peripheral speed than the first roller. The necking-in of the film in the gap between the two rollers is considerably reduced if a heat-transfer liquid is applied betwen marginal portions only of the film and the corresponding peripheral portions of the second, cooled, roller.
Claims9
In a process for producing polymeric film, wherein a polymeric film, while it is at a temperature at which it is readily deformable, is longitudinally stretched in a zone where the film is unsupported by drawing the film away from said zone at a speed which is greater than the speed at which the film is fed into such zone, the improvement of supplying a heat-transfer liquid between the film and a cooling roller onto which the film is recieved at the end of its travel through said zone, and wherein the heat-transfer liquid is supplied between marginal portions only of the film and the corresponding peripheral portions of said cooling roller thereby to reduce and stabilise the necking-in of the film on said cooling roller.
Dependencies are inferred from the claim text.