GB1159997A - Processes of Making Flexbiel Air-Permeable Sheet Products - Google Patents

Abstract

1,159,997. Coated sheet material. A. F. SCHRAMM. 23 Aug., 1966, No. 37658/66. Heading B2E [Also in Divisions B5 and D1] Flexible air permeable sheet material is made by applying a liquid to a face of an airpermeable flexible sheet to moisten at least a part of the face, applying particles of a theirmoplastic material to the face, the sheet and the thermoplastic material being insoluble in the liquid which does not act as a plasticizer therefor and the liquid being such as to act as a temporary adhesive to retain particles on the face where moistened, removing particles from the face which are not retained by contact with the liquid, and applying heat to soften the particles and permanently bind the particles to the face, the liquid or the particles or both being applied to the face only in predetermined spaced positions of such size and spacing that the retained particles do not form a continuous film and cover less than half of the area of the face so as to preserve the flexibility and air-permeability of the sheet in the finished product. Pressure may be applied in addition to the heat. Prior to the application of heat and pressure a second airpermeable sheet which is insoluble in the liquid may be placed against the face and the retained particles, pressure being exerted to bind the two sheets together. The liquid may be water, optionally containing a thickening agent e.g. a C 1-3 alkyl ether of cellulose. The thermoplastic powder may be applied through a die such as a reticulated member provided with holes in the spaced pattern desired. The flexible sheet may be a woven or knit fabric of cotton, wool, silk or synthetic resin fibers or matted glass or rock wool fibers or foamed polyurethane. The material which is plyed with the flexible sheet making a laminate can be any of the above mentioned materials and can be either the same or different from the material of the base sheet. For automobile seat covering, the second sheet may be a thick, cushioning layer of polyurethane foam rubber, cotton or felt. The thermoplastic material may be polyethylene, polypropylene, polyvinyl acetate, polyvinyl chloride, polymethylmethacrylate. The laminated products may be used for shirt collars, stitching tapes, brassieres, shoulder pads and automobile seat covers. In Fig. 6 apparatus comprises a supply ohamber 15 for the thermoplastic powder 17, a lifting conveyor 19 with power drive for delivering the powder through hopper 21 to the top of an endless applicator belt 23. Base sheet 25 is fed between print rollers 27 and the coacting pressure roller 31 whereby liquid 29 is printed upon a face of the sheet. The printed sheet is then forced by gravity rollers 33 and 35 against and upon the thermoplastic powder travelling on the endless belt 23. The sheet then passes under tapper device 37 with the powder-treated face of the sheet down so that non-adhered powder falls off under the tapping and returns to the supply of the powder in vessel 15. The sheet is then passed over guide rollers 40 and 42, through heating chamber 43, and into cooling chamber 45. In the examples: 1) a bleached woven cotton fabric print cloth was placed beneath a framed silk screen that had been given a water proof coating except in predetermined spaced areas which were left uncoated for the adhesive liquid to pass through. The adhesive liquid was a 2% solution of a cellulose ether in water and the liquid was forced through the uncoated pattern openings of the silk screen with a squeegee. The silk screen was then removed and polyethylene powder applied as a continuous layer upon the moistened side of the fabric. Non-adhered powder particles were removed by shaking and the coated fabric was then heated to dry the product and fuse the individual clusters of foam plastic particles; 3) before cooling the product of example 1 after the heating step, another sheet of the print cloth is laid upon and pressed by a cold plate against the treated surface of the base sheet; 4) a sheet of the same fabric was applied to the product of example 1 using a heated iron; 5) cotton fabric was moistened with water, vinyl chloride sheeting with spaced holes formed therethrough was laid against the moistened face of the fabric and polyethylene powder spread over the apertured plastics sheet, the plastics sheet then being removed and the coated fabric heated; 6) an assembly of facing and backing fabrics with a cotton batting interliner with polyethylene in spaced particle arrangement on the inside surface of one of the fabrics is warmed to soften the binder and compressed only along those regions where the binder is present so that the binder bonds together the two fabrics to produce a quilting for use as a shoulder pad, bed cover or chair or seat cushion; 7) the procedure in example 1 is followed, and the cloth is reversed and subjected to the same treatment on its back face to produce a sheet suitable for use as an inter-liner for wool stitching tape; 8) the procedure of example 1 was followed except that polyethylene particles were also admixed with the liquid before application.