PRODUCTION OF NON-OPTICALLY ROTATIVE FILM

摘要

PURPOSE:To obtain a non-optically active film having good smoothness and flatness by interposing a woven or knitted fabric having stretchability between a holding part of a treating device and a treating film and holding said film. CONSTITUTION:The stretchable woven or knitted fabric elongates according to elongation of the untreated film and contracts according to the shrinkage thereof under treating conditions and does not shrink or elongates independently. Blended fibers contg. >=10% one or more kinds among natural fibers, regenerated fibers and inorg. fibers are more preferable particularly in terms of heat resistance. The adhesiveness to the untreated film is improved if the woven or knitted fabric impregnated or coated with a dilute soln. of the resin used for said non-optically active film or coated therewith by melt extrusion is used. The four sides of the untreated film 1 are fixed to the holding part 3 via the strethcable woven or knitted fabric 2. All wrinkles 5 appear on the fabric 2 and do not appear at all on the film 1.