| 摘要 |
1482675 Dense fibrous webs; finishing fabrics J W SUOMINEN OY 13 Nov 1974 [13 Nov 1973] 49179/74 Headings D1R and D1S A needle punched non-woven web consisting partially or exclusively of thermoplastic fibrous material is subjected to repeated blows, the heat thus generated being sufficient on its own or in combination with heat applied before or during the blows to raise the temperature of the fibres to the point at which they deform but below that at which they melt or adhere, so that the fibres deform so as to contact each other over larger areas of each fibre. The density of the web is thus increased, eg. 2.5 fold, to give a voids content of e.g. less than 20% and the frictional contact between fibres is so strong that the strength of the web is increased e.g. 4 or 5 fold. The ends of fibres at the web surfaces expand to produce a smooth-surfaced web. The thermoplastic fibres exemplified are 50 mm, 1.5 denier polyester shrinkable fibres. Others mentioned are polypropylene, polyvinyl alcohol, polyamide, polyacrylonitrile and glass. An equal proportion of natural fibres may be present. The blows may be applied by a plate mounted on a shaft running transverse to the direction of travel of the web the preferably upstream end of the plate being connected by a rod to a crankshaft or wheel to rock the plate with a stroke length of 5 to 10 mm. Below the plate is an optionally heated and/or vibratingly sprung support. The web may be passed several times through the reciprocating apparatus. The frequency of reciprocation may be 200 to 1500 times per minute. Specified products are leather substitutes and a carpet. |
