GB829908A - Fibrous element and method and apparatus for making same - Google Patents

Abstract

<PICT:0829908/IV (a)/1> A sliver 19 comprising a mixture of non-adhesive and potentially adhesive fibres is drawn by rolls R through a die 20, a heated chamber 18 where the potentially adhesive fibres are rendered tacky by a separately introduced solvent, and a smaller die 23 producing a compressed filter body, which may be of such size and shape as to form the absorbent element in dental and surgical pads, dressings or tampons but which, as shown, is a rod 31 in which the tacky fibres have set and around which a paper web 55 is wrapped by a former 50 and gumming means 60, lengths cut from the wrapped rod 31 being used within the wrappers of cigarettes as filter plugs. The non-adhesive fibres are of regenerated cellulose such as mechanically or chemically crimped fibres of rayon staple and preferably comprise 75 to 90% by weight of the sliver, the rest of which is comprised by the potentially adhesive fibres, which may be crimped and are vinyl resins such as polyvinylchloride or copolymers of vinyl chloride and vinyl acetate or of acrylonitrile and vinyl chloride. Both non-adhesive and potentially adhesive fibres are at least 9 microns in diameter (preferably 1 to 1 1/2 denier) and may vary in length from 5/8 inch to 2 1/2 inches, many of the shorter fibres being disposed transversely of the rod 31. As described, the potentially adhesive fibres are rendered tacky by introducing as a solvent liquid acetone, directly on the sliver 19 or on to the chamber wall for vaporization, the chamber 18 being heated to about 110 DEG C. by one or more heaters 25. Setting of the rod 31 occurs outside the die 23 or partially therein. The diameter of the former 50 is less than that of the die 23, to reduce the rod diameter further. To eliminate fouling of the dies 20, 23 they are of polytetrafluoroethylene and the die 20 has a p bevelled rear edge. The chamber 18 may be vented via flats on the outside of the die 20. The fibres may be coloured, dyes being incorporated with the spinning solution or by bath dyeing the spun filaments from which the staple is cut. Essential oils, and aromatics such as perfume and menthol, may be incorporated. The rayon fibres of the completed filter swell as they become moistened during use. The Registered Trade Mark "Vinyon" is mentioned.