| 摘要 |
1,181,854. Non-woven fabric. E.I. DU PONT DE NEMOURS & CO. 5 June, 1967 [6 June, 1966], No. 25892/67. Heading D1R. A non-woven web comprises polyester fibres having an asymmetic birefringence across their diameters, a density greater by 0.053 to 0.060 g/cc than that of. the fibres with the polymer in the fully amorphous condition, a three dimensional, curvilinear, reversing helical crimp with a crimp frequency of 3.15 - 9.84 crimps/cm, and a shrinkage tension (as defined) of substantially zero, the web having a density of 0.003 - 0.04 g/cc and a filling support weight (as defined) of at most 1 kg. The fibres can be of polyethylene terephthalate, polyethylene terephthalate/isophthalate, polyethylene terephthalate/5-(sodium sulpho) isophthalate or poly (p-hexahydroxylyene terephthalate). The web can be bonded with an acrylic copolymer by spraying with the polymer and heating. The web is made by heating a bath of asymmetrically birefringent, helically crimped polyester fibres to 170 - 200‹C for 2-8 min so as to provide an increase in the crimp frequency of 7 to 20%. The ball can be formed by carding or pneumatic means. The fibres can be precrimped by heating to 140‹C. |
