Patent GB-1096583-A (GB)
Title: Improvements relating to flexible sheet material
Inventor: PEARSON ROLAND WILLIAM
IPC: D04H3/009
Filed: 1964-05-09
Abstract: A leather-like material comprises a consolidated mat of interpenetrated crimped continuous filaments bonded together with a resinous or elastomeric bonding agent, the interpenetration of the filaments being in the nature of an intermingling in three dimensions produced by laying the crimped continuous filaments under tension and subsequently releasing the tension, having on at least one surface thereof a formation comprising flock fibres disposed substantially normally with respect to the surface of the consolidated mat and bonded to this surface by an adhesive composition.  The flock fibres are electrostatically deposited on the surface coated with the adhesive composition, e.g. by discharging the flock through a hopper grating, a potential difference say of the order of 50 kilovolts being applied between the grating and an earthed base supporting the adhesive coated consolidated mat.  Alternatively the flock may be deposited, and these electrostatically oriented by mechanically agitating the consolidated mat by passing the mat over rapidly rotating beater bar.  The flock fibres may be deposited on the continuously moving, adhesive coated, consolidated mat which is then passed to a vacuum extractor in which unadhered flock fibres are removed, and also passed through an oven to evaporate solvent from the adhesive composition and cure the adhesive.  The flock fibres may be of any desired colour, different coloured fibres being applied from different hoppers.  Flocks of particular colours may be deposited on particular areas of the mat, and flocks of different fibre lengths to provide an embossed effect, or of different natures over different areas of the mat may be deposited, e.g. nylon flock and rayon flock over areas liable to heavy and light wear respectively.  Any adhesive composition may be used, e.g. neoprene solution adhesives, isocyanate adhesives, latices of natural and synthetic rubbers, polyvinyl chloride pastes.  A priming adhesive as well as a main adhesive may be used.  Suitable consolidated mats are described in British Patent No. 989,433. The mat may be prepared from crimped continuous nylon filaments. A layer of staple fibres may be provided on at least one surface of the mat, e.g. polypropylene staple fibres needled as well as bonded to the mat and the flock fibres deposited electrostatically thereon.  In the example, polypropylene fibres are needled to a mat comprising nylon filaments and the web impregnated with natural rubber latex which is then gelled.  A priming coat of a neoprene solution is applied and solvent removed by infra-red heating.  A second adhesive comprising polyester, triisocyanate, cellulose acetate butyrate in ethyl acetate, butyl acetate, is applied and black nylon flock deposited electrostatically thereon.  The flocked material is heated in an air oven to dry and cure the adhesive.  The products are said to be suitable for use in manufacturing bootees, slippers and other footwear.ALSO:A leather-like material comprises a consolidated mat of interpenetrated crimped continuous filaments bonded together with a resinous or elastomeric bonding agent, the interpenetration of the filaments being in the nature of an intermingling in three dimensions produced by laying the crimped continuous filaments under tension and subsequently releasing the tension, having on at least one surface thereof a formation comprising flock fibres disposed substantially normally with respect to the surface of the consolidated mat and bonded to this surface by an adhesive composition.  The flock fibres are electrostatically deposited on the surface coated with the adhesive composition e.g. by discharging the flock through a hopper grating, a potential difference say of the order of 50 kilovolts being applied between the grating and an earthed base supporting the adhesive coated consolidated mat.  Alternatively the flock may be deposited, and these electrostatically oriented by mechanically agitating the consolidated mat by passing the mat over rapidly rotating beater p  bar.  The flock fibres may be deposited on the continuously moving, adhesive coated, consolidated mat which is then passed to a vacuum extractor in which unadhered flock fibres are removed, and also passed through an oven to evaporate solvent from the adhesive composition and cure the adhesive.  The flock fibres may be of any desired colour, different coloured fibres being applied from different hoppers.  Flocks of particular colours may be deposited on particular areas of the mat, and flocks of different fibre lengths to provide an embossed effect, or of different natures over different areas of the mat may be deposited e.g. nylon flock and rayon flock over areas liable to heavy and light wear respectively. Any adhesive composition may be used e.g. neoprene solution adhesives, isocyanate adhesives, latices of natural and synthetic rubbers, polyvinyl chloride pastes.  A priming adhesive as well as a main adhesive may be used.  Suitable consolidated mats are described in British Patent No. 989,433. The mat may be prepared from crimped continuous nylon filaments. A layer of staple fibres may be provided on at least one surface of the mat e.g. polypropylene staple fibres needled as well as bonded to the mat and the flock fibres deposited electrostatically thereon.  In the example, polypropylene fibres are needled to a mat comprising nylon filaments and the web impregnated with natural rubber latex which is then gelled.  A priming coat of a neoprene solution is applied and solvent removed by infra-red heating.  A second adhesive comprising polyester, triisocyanate, cellulose acetate butyrate in ethyl acetate, butyl acetate, is applied and black nylon flock deposited electrostatically thereon. The flocked material is heated in an air oven to dry and cure the adhesive.  The products are said to be suitable for use in manufacturing bootees, slippers and other footwear.