Patent GB-542774-A (GB)
Title: Improvements in production of artificial straw and like products
IPC: D06M13/192
Filed: 1940-07-26
Abstract: 542,774. Artificial filaments, straw &e. BRITISH CELANESE, Ltd. July 26, 1940, No. 12186. Convention date, Aug. 10, 1939. [Class 2 (ii)] Artificial straw-like materials are obtained by applying pressure to a sliver, band, or roving containing thermo-plastic filamentary material, a plasticizer for the material, and a volatile solvent for the plasticizer that is not a solvent for the .material, the latter being in a softened state by reason of the presence of the plasticizer, and then removing the volatile solvent by drying the resulting product at an elevated temperature. Products of varying stiffness according to the purposes for which they are designed may be obtained. They may be used in millinery, or in making ornamental ropes, baskets, wicker furniture, automobile upholstery, or mats. The filamentary materials may be filaments or staple fibres having a basis of cellulose acetate or other cellulose ester, ether, mixed ester, mixed ether or ether-ester. The filaments may be treated with a solution of plasticizer in a solvent for the plasticizer such as ethyl or methyl alcohol, benzene, toluene, dichlorethylene, or diethyl ketone. The plasticizer may be methyl methoxy ethyl phthalate, dimethoxy ethyl phthalate, diethyl phthalate, dibutyl phthalate, triacetih, tricresyl phosphate, triphenyl phosphate, ethyl o-toluene or p-toluene. sulphonamide. Staple fibre in the form of abraded or staplized yarns of continuous filament origin, or bands, slivers, or rovings built up from staple fibre may be used. The thermo-plastic filaments or fibres may be used in admixture with non thermo-plastic fibres, e.g. cotton, wool, silk, protein artificial fibres, or regenerated cellulose. The softened sliver is passed through adjustable nip or quetch rolls. A slight stretch or tension may be imposed on the sliver before or after nipping to control the coalescence of the filaments or fibres. The sliver of filaments may be given a slight twist prior to the pressure treatment. The solvent for the plasticizer may also have a softening action on the thermoplastic material. If desired the plasticizer may be incorporated in the spinning solution. From the nip or quetch rolls, the product is passed through a closed chamber maintained at a temperature high enough to evaporate off the volatile solvent, e.g. 70-130‹ C. Crossdyeing effects may be obtained with products made from coalesced fibres of different kinds. Dyed filaments of different colours may be coalesced. Noils and like irregularities may be included in carded yarns or rovings to be subjected to the treatment. The filaments may contain dyes, pigments, and other effect or filling materials. Filaments of varying diameter along their length may be used. If desired, the sliver of filaments may be caused to coalesce at intervals along its length, leaving uncoalesced portions. Application of dyestuffs through the medium of the plasticizer may be intermittent. The sliver may be printed with novelty colour effects along its length prior to coalescence into a straw-like body. The pressure rolls may be of any desired shape or surface contour and crinkled, crimped, embossed, and other effects may be obtained. Two or more pairs of rollers may be used.