METHOD AND DEVICE FOR CONTINUOUS TWO-AXIS STRETCHING OF FILM BASED ON TRANSITION THROUGH SADDLE-SHAPED SURFACE

摘要

FIELD: technological processes.;SUBSTANCE: group of inventions relates to method and device for continuous two-axis stretching of film based on transition through saddle-shaped surface. In method of biaxial stretching of film surface, when forces of transverse and longitudinal stretching are applied to another tangent plane, film is subjected to smooth transfer in three-dimensional space from narrow face through saddle-shaped surface to wide face. Uniform thickness of the biaxial stretchable film is controlled by controlling the shape of the saddle-shaped surface. Proposed device comprises module with angular arrangement of wheels and module with parallel arrangement of wheels. Angle between two wheels of transverse tension in module with angular arrangement of wheels is adjustable. Two wheels of longitudinal tension in module with parallel arrangement of wheels are arranged in parallel. Transverse stretching of the film is achieved by rotating the transverse stretching wheel. Longitudinal stretching of film is achieved due to difference in linear speeds of wheel of transverse stretching and longitudinal stretching wheel. In compliance with this invention, coupled wheel structure is used, saddle-shaped surface is used for correction of skew and contact surface between film and stretching element is reduced with prevention of friction surface damage.;EFFECT: ensuring uniformity of film thickness as an end product.;6 cl, 3 dwg