| 摘要 |
A non-woven porous seamless shaped fabric article is formed by moulding to a predetermined shape a fluffy, carded sheet of initially unbonded interlaced mixed staple fibres, the moulded fibrous sheet being then compacted and unified into its stable final shape by simultaneous soft-pressing and heating e.g. to 250 DEG to 450 DEG F. which effects mutual autogenous interbonding of thermoplastic binder fibres included in the sheet, all the fibres being thereafter coated and interbonded by a fibre sizing latex; said staple fibres having a length of one to two inches and including 30 to 50% by weight of unplasticized undrawn polyester fibres, said undrawn fibres being initially amorphous and thermoplastic but having been rendered crystalline during said heating. The fibrous mixture also comprises unplasticized drawn polyester staple fibres in the proportion of 10% to 30% by weight and cellulose staple fibres such as viscose-rayon, cotton or ramie. A suitable fibre-sizing latex is an aqueous carboxylic acrylate polymer latex dispersion containing a curing agent such as 1, 3 bis(hydroxymethyl)-2-imidazolidinone. Moulding may be carried out by fitting the carded fibrous web over a heated male mould, applying to the web-covered mould a thin stretching non-adhering silicone rubber blanket, the mould being located on a platform provided with holes connected to a vacuum line, and applying suction to produce a vacuum between the blanket and the mould whereby the blanket is uniformly pressed against the web. Upon releasing the vacuum and removing the moulded article from its mould the article may be impregnated with the fibre-sizing latex by positioning it, convex side up, under a dispensing head containing small orifices through which the latex dispersion is allowed to stream upon the article, after which the latter may be subjected to heating with hot air to dry it and cure the size coating. Where greater stiffness and strength is needed in the moulded product, two or three plies of fibrous sheet material may be lapped together. The plies may differ in fibre composition e.g. the two outer plies may be of the type previously described and an inner ply may consist of polyvinyl chloride fibres. The fibrous sheet material may be needled before moulding. |
