GB1120872A - Process for the production of a staple fibre from films - Google Patents

Abstract

1,120,872. Production of staple fibres from films. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 14 Feb., 1967 [16 Feb., 1966], No. 6928/67. Heading B5B. Staple fibres are produced by cutting in the lateral direction a strip of highly crystalline thermoplastic film which has been stretched in the longitudinal direction (at a stretching ratio sufficiently high, having regard to the stretching temperature, to render the film fibrillatable) to form clippings, the dimension of each clipping in the direction parallel to the longitudinal axis of the film being equal to the length of the largest of the staple fibres to be obtained from that particular clipping which clippings are subsequently fibrillated to form staple fibres. The clippings may have the same dimensions. The largest dimension of the clippings may be parallel to the direction of stretch of the film. The stretched film strip may be crimped before being cut into clippings. The clippings may be fibrillated in a carding machine. The film strip may be brought into the form of a fibrous strand by twisting before being out into clippings. The clippings may be out from a number of film strips situated next to one another and obtained by cutting a wide extruded film web longitudinally into film strips of the same width. The dimension of the clippings in a direction parallel to the direction of stretch of the film may be 20 to 60 mm. A particularly suitable film material is highly crystalline polypropylene or high density polyethylene. The width of the film strips is generally 5 to 25 mm., preferably about 15 mm. The stretching ratio is in general between 7:1 and 15 : 1, preferably about 10 : 1.