Patent GB-801333-A (GB)
Title: Improvements in or relating to sheet material adapted for use in providing articles with a pile finish
IPC: D04H11/00
Filed: 1956-10-16
Abstract: 801,333. Self-supporting flock coated sheet materials. B.B. CHEMICAL CO., Ltd. Oct. 16, 1956 [Oct. 17, 1955], No. 31417/56. Class 140. Self-supporting flock coated sheet material, suitable to be secured pile surface outwards to an article to provide a pile finish, is produced by providing a carrier sheet with a continuous film of a solution of film-forming material in a volatile organic solvent and having a viscosity (measured by the time taken for a # inch steel ball weighing 3.5 gm. to fall through 40 c.m. of the material at 25‹ C.) of less than 30 seconds, depositing fibres on to said film and removing the solvent from said film to cause it to form a porous flexible supporting layer which may be stripped from the carrier sheet, the fibres having end portions embedded in said layer and project substantially perpendicularly therefrom to provide a pile surface. As shown in Figure 3, carrier sheet 20 from roll 24 passes over the upper surface of table 22 and under spreader 28 which deposits a uniform continuous film 12<SP>1</SP> of a solution of film-forming liquid. Flock sifter 30 deposits flock fibres 14 on to the film while the carrier sheet is simultaneously subjected to vigorous vibration by beater bar 32 to ensure that the majority of fibres extend substantially perpendicular to the film. In oven 34, film 12<SP>1</SP> dries to form sheet material 10, as shown in Figure 2, comprising self-supporting porous and flexible supporting layer 12 with the formation of pores 18 and dimples 16 which are out of contact with carrier sheet 20 due to the unequal shrinkage of the film between the fibres. A laminate may be produced by removing the porous supporting layer 12 from the carrier sheet 20, applying a coating of adhesive to a backing sheet and applying layer 12 pile surface outwards to the coating of adhesive, the backing sheet having an adhesion resistant surface such that adhesive coated layer 12 can be stripped therefrom. In Figure 4, adhesive transfer roll 54 applies adhesive 56 from trough 58 to the surface of sheet 52 as sheet 52 is fed along frame 50 from roll 60. Sheet material 10 on carrier sheet 20 fed from roll 40 passes through rollers 64 where carrier sheet 20 is stripped and coiled at driven roller 66. If desired, a spray 71 applies solvent to the unflocked surface of material 10, prior to lamination with sheet 52 at rollers 68 and 70. The porous layer 12 may be applied to an article, as shown in Figure 1, where sheet material 10 is laid flock surface downwards on sheet 44 so that the fibres 14 of sheet 10 interlace with pile surface of sheet 44. Layer 12 may be treated with solvent to activate the adhesive material in layer 12 or may be coated with adhesive comprising a volatile organic solvent, and backing layer 46 to which sheet material is to be applied is pressed against sheet 10 by hand roller 48. Suitable carrier sheets are smooth surfaced paper sheet with an adhesion resistant coating, e.g. silicone coating, or lubricated metal sheet, e.g. stainless steel. The continuous films may be from 0.005 to 0.012 inches thick and may comprise an adhesive, e.g. natural and synthetic rubber, polychloroprene, butadiene acrylonitrile, butadiene styrene, and a compatible resin, e.g. polyvinyl chloride or copolymers of vinyl chloride and vinyl acetate or vinyl alcohol, urea-aldehyde and phenol-aldehyde resins, together with a curing agent, e.g. p-toluene sulphonic acid. Suitable solvents are toluene, xylene, petroleum solvents, methyl isobutyl ketone, methyl-ethyl ketone. The fibres may be rayon, nylon, cotton or other fibrous material and are preferably of lengths between 0.25 and 0.75 mm. Suitable backing sheets are woven materials, e.g. loosely woven cotton fabric, adhesion-resistant coated paper, and shearling sheepskin leather. The adhesive may be heat, solvent or pressure sensitive.