GB1088376A - Patterned non-woven fabrics - Google Patents

Abstract

A process for producing a patterned non-woven fabric of natural or synthetic fibres comprises subjecting a web or batt of fibres to the action of one or more fine columns of high impact-pressure streams of non compressible fluid such as water, while supporting the web on an apertured patterning member so that the fibres are rearranged into recurring primary areas of interentangled or "tanglelaced" fibres which are connected by secondary fibres of groups of secondary fibres in ordered arrangement. The term fibres includes continuous filaments. The tangle laced areas are defined as having an "impenetrability rating" (as defined in the Specification) of at least 0.5 and the fabric produced must have a "structural measure of fibre entanglement and cooperation" (as defined in the Specification) of at least 0.1. Where secondary fibres emanate in bundles from opposite side of the tanglelaced areas a further factor, "rub strength ratio" is applicable as a criterion the value of which must be at least 0.7. The products of the invention may comprise two or more strata in which the pattern of primary areas and secondary fibres differ, and this effect may be achieved by the use of a patterning support member the face of which is non planar, or which has planar and non planar areas, e.g. a plate having apertures and upstanding pins or pyramids. The fibres selected may desirably have the property of crimping, elongating or shrinking when the fabric is subjected to an appropriate after-treatment and are initially laid in the web in random or oriented relation e.g. by carding, air deposition or slurry deposition. The initial mat may be cross-lapped and may include a scrim fabric as a reinforcing layer or a layer of yarns all laid in one direction, e.g. as warp yarns (Example XXX). A paper web of short cellulosic fibres (Example XIII) or of synthetic fibres (Example XIV) may be laid on a fibrous web and incorporated into the tanglelaced product by the process of the invention. The patterning member may have apertures of various forms or merely recesses, protrusions and grooves and may consist of a woven wire screen, perforated plate or the like. Contoured patterning members may be used for the direct formation of garments. The materials produced may be dried on the patterning member and subsequently dyed, printed, heat treated, treated with resins, binders, sizes, finishes, surface-coated and/or pressed, embossed or laminated with other materials such as foils, films or the like. The high impact pressure jets are normally emitted from nozzles placed a few inches from the fibrous web but the nozzles may be arranged to contact the surface thereof. The jets may not necessarily be arranged at right angles to the surface and may be arranged to oscillate and to traverse the web surface repeatedly, if desired at increasing pressures. To increase fibre mobility and thus also the ease of producing the tanglelaced areas the fibrous web may be treated first with a wetting agent. Specific fibres referred to include polyethylene terephthalate in staple or continuous form, isotactic polyproplene, acrylic and polyacrylic fibres, cotton, rayon, short cellulosic fibres, hydroxypivalic acid fibres, steel wool and wool. Two-component fibres of trilobal cross-section and containing polyethylene terephthalate and polyhexamethylene adipamide or of ribbon-like cross-section with the same components in side by side relation are referred to as are also two-component fibres containing polyhexamethylene adipamide with polycaproamide and polyhexamethylene adipamide with a copolyamide of hexamethylene adipamide and hexamethylene sebacamide. Heat setting of the patterned fabrics, if desired under pressure, may be employed. In Ex. IX a post-treatment comprising sanding the surfaces of the fabric with emery paper, clipping the raised fibres and consolidating under heat and pressure to provide a flannel-like fabric is referred to. In Ex. XI the use of an acrylic resin as a binder is referred to. The products of the invention are of use in upholstery, drapery, clothing and as diapers, bandages, blankets and reinforcements for rubber goods such as tyres, conveyor belts and the like.