| 摘要 |
1457966 Bonded fabrics ANIC SpA 29 March 1974 [10 April 1973] 14150/74 Heading D1R A plurality of members impregnated with an aqueous dispersion of a binder is temperarily immersed in a liquified gas to coagulate the binder and the liquified gas is removed or allowed to evaporate from the product. Specified members are natural or synthetic fibres, filaments and fibrils and bodies formed therefrom such as woven and knitted fabrics. The binder may be a copolymer of butadiene with acrylonitrile or styrene, an acrylic polymer optionally including free carboxyl groups or a homopolymer, copolymer or terpolymer of vinyl chloride or vinyl acetate. The liquified gas may be air nitrogen or oxygen at a temperature of -30 to -220‹C. In the example a band of felt constituted by 90% of 1.5 denier 4 mm long nylon fibres and 10% viscose fibres is immersed in a 40% aqueous dispersion of a butadiene-acrylonitrile polymer plus curing agents and accelerators, and calendered to adjust the uptake such that the finished product contained 120-130 parts of dry binder per 100 parts fibres. The impregnated felt is passed around a roller immersed in a tank of liquid air, the speed of the felt and the depth of the roller in the tank being such that the felt is at 0‹C as it passes around the roller and at -40‹C as it leaves the tank. The frozen felt is thawed in a first oven and heated to cure the coagulated binder in a second oven. Alternatively one long oven at 160‹C is used to thaw the felt and cure the binder. |
