Patent GB-816673-A (GB)
Title: Non-woven fabric and method of producing same
IPC: D04H1/70
Filed: 1955-06-16
Abstract: 816,673. Paper; bonded fibre fabrics. GRISWOLD, H. W. June 16, 1955 [June 16, 1954; April 26, 1955], No. 17434/55. Classes 96 and 140. [Also in Group IX] A bonded-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 randomly-disposed areas of relatively small fibre density, the rearranged fibres being in mechanical engagement with one another in substantially unstressed positions and in mechanical equilibrium. Preferably the fabric is net-like or lace-like and composed of fibre bundles 23 of yarn-like appearance, in which the fibre segments 24 are substantially parallel, bordering areas 29 of almost zero fibre density and most of the individual fibres such as 28a, 28b, 28c, are common to more than one yarn-like bundle. Such a fabric is 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. Alternatively, a flexible chamois-like material may be produced from a water-laid web containing 10 per cent by weight of binder. The fibres in the webs from which the fabric is formed may be disposed at random as by air- or waterlaying or may be given a definite direction of lay by carding, and several webs may be superimposed and impregnated with binder prior to working up into the fabric. Further adhesive may be applied by printing to strengthen the fabric. 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 “ inch to 2 inches although shorter fibres may be used. Suitable bonding agents are beaten wood pulp, caroa, and ramie, karaya and locust bean gums, gum arabic, starch, polyvinyl alcohol, polyvinyl acetate, carboxymethylcellulose, solvent - softenable binders such as polyvinyl chloride and polyvinyl butyral, and the thermosetting binders such as urea- or melamine-formaldehyde used before they are set. Preferably, the binder is softened either with water or solvent as required and sufficient water is added-50 to 250 per cent by weight of the dry web-so that surface tension tends to draw fibres together. The fabric may be produced by taking such a wetted web and manually bunching it, rolling it in the hands, and opening it one or more times. Alternatively, the bunched web may be placed in a closed can having holes to allow escape of excess water and the can shaken vigorously by hand or mechanical means. In another arrangement the wetted fibrous web may be clamped in a deformable rectangular frame, if desired between facing sheets of rubber or gauze, and the frame deformed to apply biasing stresses to the web to cause rearrangement of the fibres. For a continuous process, wetted webs may be fed by resilient belts, e.g. of sponge rubber, through one or more sets of groups of rollers arranged to oscillate both axially and/or circumferentially as in a felting machine. Reference is made to rearranging the fibres by use of the force of flowing water or other fluids.