FASERVLIES BZW. VLIESSTOFF

摘要

1510580 Biaxially orientated non-woven fabric KENDALL CO 8 Dec 1976 [19 Dec 1975] 51270/76 Headings DIN and D1R A biaxially orientated non-woven fabric composed of long fibres of length 0.5in. or more and short fibres of length less than 0.5in. comprises areas 12 of low fibre density having a finger-like configuration and areas 11 of high fibre density, the majority of the fibres in the areas 12 of low fibre density being long fibres which are orientated in a direction substantially normal to the fingers, the majority of the fibres in the portions of the high fibre density areas 12 directly adjacent the fingers 11 being orientated substantially parallel to the fingers and the majority of the short fibres being disposed in high density areas 11. Preferably, slivers 14 of long fibres are drafted by rolls 15 and propelled by air from blower 16 through venturi 17 to distributor chamber 21 whilst short fibres are fed by a further air stream from feeder 18. Suction box 29 collects the fibres on moving conveyor screen 22. Preferably fixed finger-like striping bars 23 are disposed at regular intervals above and across the width of the screen, e.g. 0.125in. wide bars are located at 4 in between their centers. The deflection of air between the bars deposits the majority of the fibres on the screen between the bars and orientated in the machine direction. The minority of fibres which are not deflected will straddle a bar. Their ends will be orientated longitudinally in dense areas 11 and this will straighten the middle portion and orientate it transversely. As the fibre weight per unit area is increased the bars have less effect so that a thick web has an upper layer of randomly aligned fibres. In alternative embodiments the stripping bars are orientated transversely or replaced by impervious areas e.g. star shaped areas (61, Fig. 6, not shown) formed on screen 22 with paint or plastics. The web may contain thermoplastic fibres which bond it when softened by heater 25. In example 1 the web comprises 14 g/yd2 of 1 9/16" 3 denier rayon, 8 g/yd2 of �" 3 denier vinylacetate/vinylchloride thermoplastic copolymer fibres and 4 g/yd2 of wood-pulp fibres. A plaid fabric (Fig. 7, n.s.) may be obtained by superimposing two layers with their stripes at right angles.