Patent GB-836396-A (GB)
Title: Non-woven fabric and means and method of producing same
IPC: D04H1/70
Filed: 1955-06-16
Abstract: 836,396. Forming fibres into webs. GRISWOLD, H. W., and PEARCE, G. W. June 16, 1955 [June 16, 1954(2); April 26, 1955], No. 17435/55. Classes 120(1) and 120(3) [Also in Group VIII] A non-spun fibre fabric comprises a fibrous web in which the fibres have been rearranged into  areas of relatively great fibre density formed by bundles of fibre segments bordering areas of relatively small fibre density arranged in a predetermined pattern, the rearranged fibres being in mechanical engagement with one another in substantially unstressed positions and in mechanical equilibrium. Typically the fabric has a patterned lace-like appearance, or as shown, simulates a woven fabric and is composed of fibre bundles 31 of yarn-like appearance, in which the fibre segments 30 are substantially parallel, bordering areas 34 of almost zero fibre density, and most of the individual fibres such as 28a, b, c are common to more than one yarn-like bundle. To increase the strength of the fabric an adhesive binder may be included in the web from which the fabric is formed (see Group VIII). Such fabrics are suitable for use in surgical dressings, as coverings for sanitary napkins and diapers, as a gauze substitute, and as wiping cloths, towelling, filter materials, lining materials, or industrial base fabrics. The fibres in the webs from which the fabric is formed may be disposed at random as by air- or by water-laying or may be given a definite direction of lay by carding and several carded webs may be superimposed. Suitable fibres are cotton, wood, wool, jute, ramie, abaca, viscose rayon, cuprammonium rayon, cellulose acetate, nylon, and vinyl chloride-acrylonitrile copolymer, preferably in lengths of 1/4 inch to 2 inch although shorter fibres may be employed in admixture therewith. The fabric may be produced by sandwiching a wetted web between a lower patterned moulding member of polymethylmethacrylate, hard rubber, or corrosion-resistant metal and an upper resilient, e.g. sponge rubber, sheet and imparting relative movement in one or more directions parallel to the plane of the web to the sheet and moulding member, whereby the fibres are displaced into the pattern formed by the recesses in said member. The moulding member may have two sets of square section grooves intersecting at right angles, a raised square pattern of right circular cylinders, of right frusta of square or hexagonal base pyramids or cones, or a raised pattern of equilateral triangular wedges, or a lace negative pattern, or may be woven mesh screen having straight wires in one direction and crimped wires in the orthogonal direction. In one arrangement similar to a press, the web-sandwiching members are resiliently carried on woven metal screens attached to frames which are held together by luggage-type clamps while allowing movement of the members by means of hand levers engaged in eyes on one side and one end of the upper frame and fulcrumed in conical recess in the lower frame. In an alternative continuous process form the web is fed by the sandwiching members which are endless belts passing through a group of rollers arranged to oscillate both axially and circumferentially as in a felting machine. Specification 816,673 is referred to.