Patent GB-577534-A (GB)
Title: A method of producing yarns, felts and other fibrous structures and fibrous structures produced thereby
IPC: D21J1/00
Filed: 1943-08-24
Abstract: 577,534. Felt; paper; agglutinated fibrous sheet materials. RAYNER, G. F. (Sylvania Industrial Corporation). Aug. 24, 1943, No. 13783. [Classes 42 (ii), 96 and 140] [Also in Groups V and IX] A method of producing yarns, flat or moulded hat felts, paper &c. comprises dispersing into a fluid medium a potentially adhesive fibre-forming organic plastic material, e.g., cellulose derivatives, natural or synthetic resins, rubbers &c. or mixtures of the same, to form a multiplicity of discontinuous fibres and associating them, concurrently with their formation, with a multiplicity of discontinuous non-adhesive organic fibres, e.g., cotton, flax, hair, synthetic cellulosic fibres &c. or mixtures of the same. The potentially adhesive material may contain plasticizers, hardening agents, pigments, mothproofing agents &c. The organic plastic material, in one modification, Fig. 2, is sprayed under air pressure through a gun 1 into a chamber 20 containing a heated gaseous atmosphere, non- adhesive fibres 21 being blown into the chamber by a blower 23. The mixed fibres fall on to a moving belt 24 to form a batt thereon which is pinched between heated rolls 25, 26 to activate the potentially adhesive fibres to form the felt. In a further modification, a solvent may be used to activate the fibres instead of heat. In the modification of Fig. 3, the mixed fibres are received upon a rotatable mould through which suction is applied by a pipe 29a, the mould being taken from the chamber 20 and mated with another, heat and pressure being applied to consolidate the felt therebetween. In the modification of Fig. 5, corded cotton &c. is doffed by the blade 36 and receives potentially adhesive fibres produced by the gun 1b, the web 37 being then formed into a sliver and received in the can 41 or withdrawn in web form for subsequent treatment. In a further embodiment, the potentially adhesive or the non-adhesive material may be dispersed into an electrically charged field, the fibres being collected upon an oppositely charged belt or mould. In an example, the potentially adhesive fibres were produced by forcing a solution of 40 parts of vinyl acetate in 60 parts of acetone at 40 lbs. per square inch through the spray gun 1b, Fig. 5, the fibres in the silver being 85 per cent. rayon and 15 per cent. vinyl acetate. After twisting, the yarn was preheated to 250F. and then passed through a hot metal eye to compress and activate the fibres. In a further example, the adhesive fibres were produced by forcing through the gun 1, Fig. 2, a solution comprising 30 parts of cellulose acetate, 30 parts of acetone, 37 parts of ethyl acetate and 3 parts of triphenyl phosphate, the proportion of cellulose acetate fibres to cotton on the belt 24 being 10:100. In a still further example, short wool fibres were introduced by the blower 23a, Fig. 3, and the potentially adhesive fibres were produced by forcing a solution comprising 25 parts of polymerized isobutylene in 75 parts of toluene, pressure alone producing tackiness. Specification 547,288 is referred to.