Process and apparatus for making laminated sheet materials

摘要

621,867. Compound sheet materials. SYLVANIA INDUSTRIAL CORPORATION. May 17, 1946, No. 14933. Convention date, May 17, 1945. [Class 140] Laminated material is made by interposing a porous mat of unwoven fibres between a pair of preformed solid synthetic resin films, and causing the material of one or both films to flow through the mat and unite with the other film, e.g. by heating. One or both films may be supported on a temporary backing sheet which is stripped from the laminated material after its formation. Stripping may be facilitated by cooling the combined sheets. The mat may be formed from cotton, hemp, jute, flax, kapok, wool, hair, fur, silk, asbestos, glass fibres, rock wool, casein, gelatin, zein, or viscose rayon fibres, or may be made wholly or in part from thermoplastic fibres of higher melting point than the films, such as cellulose esters and ethers, vinyl polymers or copolymers, polyvinylidene chloride, or nylon. The fibres may be carded, and one or more carded webs used as the mat, or the carded web made into slivers or strands which are arranged side-byside or crossed to build up a mat. Alternatively, fibres a may be formed or dispersed in a gaseous atmosphere in a chamber 24 by means of a spray-gun 25 and settle to form a mat on the surface of a synthetic resin film B6 carried on an endless belt 12a, a second synthetic resin film B being united with the other layers between heated rolls 16. Alternatively a warp of continuous filaments may form the mat. A second warp may be placed across the first layer to give strength in two directions. The films may be of thermoplastic synthetic resin or thermosetting resin in the thermoplastic stage. Resins specified are polyvinyl and polyacrylic resins, polystyrene, polyvinylidene chloride, polythene, synthetic rubbers such as polybutadiene, olefine polysulphides, neoprene, polyisobutylene, thermosetting resins such as urea-, phenol-, or sulphonamidealdehyde resins, and alkyd resins. A minor proportion of short fibres may be included in the films. To facilitate adhesion, a solvent or plasticizer for thermoplastic fibres in the mat or the film may be incorporated in the fibres or the film. Several fibrous mats may be combined with a larger number of films so that films are on the outer surfaces of the final product. The films may contain resin, wax, asphalt, mildew- or fire-proofing materials, or colours. The films may be embossed or printed before, during, or after laminating. The product may be used for wrapping, or making bags or tubes.