| 摘要 |
<p>577,991. Fabrics composed of agglutinated fibrous materials. SYLVANIA INDUSTRIAL CORPORATION. July 30, 1943, No. 12376. Convention date, Aug. 3, 1942. [Class 140] Thick. low-density felts are made by confining a thick layer of dry, loose, intermingled textile fibres comprising thermoplastic fibres between porous members without subjecting the layer to substantial pressure and passing steam through the layer while so confined, the steam having a temperature sufficient to melt, dissolve, or soften the surface of the thermoplastic fibres to bind fibres in the felt without destroying the fibrous character of the thermoplastic fibres. The thermoplastic fibres may be of cellulose esters, ethers, or ester-ethers, synthetic resins such as polymers of coumarone, indene, vinyl compounds such as vinyl halides, vinylidene chloride, acrylic acid or its homologues or derivatives, butadiene, isobutylene, or chloroprene, copolymers of vinyl halide and vinyl acetate or an acrylic acid derivative, condensation products of an aldehyde with phenol, urea, an amine, or a sulphonamide, alkyd resins, nylon, and olefine polysulphide. Mixtures of resins with one another or with cellulose derivatives may be used. An example describes the manufacture of a battery separator from thermoplastic fibres alone, the fibres being made of a copolymer of vinyl acetate and vinyl chloride, and formed into a layer by carding. Alternatively the thermoplastic fibres may be used to bond other fibres which are not rendered tacky by the steam treatment, including cotton, flax, jute, kapok, silk, cellulose hydrate, cellulose derivatives, synthetic resins, natural and synthetic rubber and derivatives thereof, spun glass. asbestos, and mineral wool. The two kinds of fibre may be mixed by carding or in an air stream, in which case they may be blown in or on a mould to form a shaped product. The softening point of the thermoplastic fibres may be raised after the felt is made by extracting plasticizer therefrom by means of a solvent. The felt may be treated with steam while confined between a pair of flat or shaped porous-surfaced hollow platens to the interior of one of which steam may be supplied while the other is exhausted. Alternatively a felt web 6 may be led between the porous covering 1 of a rotating hollow perforated drum 2 and an endless porous tensioned travelling belt 7, while steam supplied by a pipe 4 to the interior of the drum passes outwards through the porous covering, the felt, and the tensioned belt. Specification 547,288 is referred to. The Specification as open to inspection under Sect. 91 comprises also the use as non-thermoplastic fibres of wood pulp fibres, and filaments made by slitting, cutting, or shredding non- fibrous films such as regenerated cellulose. This subject-matter does not appear in the Specification as accepted.</p> |
