| 摘要 |
<p>1307294 Leather substitute; textile treating apparatus GLANZSTOFF AG 4 May 1970 [16 July 1969] 21342/70 Headings D1R D2B and D1L A mat 1 of 80:20 polyamide/regenerated cellulose fibres prepared by wet laying an aqueous dispersion or by carding is compacted by heating and/or by needling, passed through rollers 2 then impregnated with at least three elastomeric polymer solutions of increasing concentration at intervals sufficient for the previous application to have been absorbed. A solution A of 14% polyurethane and 2% silicone or paraffin oil in dimethylformamide/ water in vat 4 is applied to the lower surface of the web by roll 3. The thickness of the liquid layer applied being determined by the separation between knife 5 and roll 3. At the same time a solution B of 16.5% polyurethane is applied to the upper surface by knife 6. A solution C of 20% polyurethane and 7% polyvinyl chloride/maleic anhydride copolymer is applied by knife 7 and a final solution D is applied by knife 11 before the binder is coagulated by passing the mat into a 40‹C water bath 12. Pairs of rollers 9 may press the mat after some or all applications of binder. The successive application of increasingly concentrated binder solution produces a large density gradient in the mat. The mat may be compressed whilst the binder is coagulating in the bath by calendering through 6 pairs of rolls. The mat may be dried, ground and coated with polyurethane.</p> |
