| 摘要 |
1353756 Non-woven fabrics JOHNSON & JOHNSON 19 April 1971 [24 March 1970 (9)] 25161/71 Headings D1R and D2B A non-woven staple fibre web is formed with areas of high and low fibre density by directing a fluid onto the web while it lies on a support member comprising a continuous impermeable part surrounding sieve-like permeable areas. An apertured member may be located between the fluid directing means and the web. As shown, Fig. 1, fibre web 43 is passed between rotating support member or drum 15 and a running apertured member or belt 30, water being sprayed from nozzles 29 through the belt, web and drum to rearrange the web fibres. Vacuum box 45 assists the dewatering and rearranging of the fibres. Drum 15 Fig. 2, is formed by continuous solid part 20 surrounding sieve parts 19, and belt 30 has apertures 31. Sieve parts 19 and apertures 31 may be of any shape and may lie in any pattern. Alternatively, Fig. 25, fibre web 128 is fed between wet-out rollers 120, 121 which control the webs moisture content to 150 to 200 p.b.w. The web is then carried on belt 130 beneath water jets 137 to rearrange the fibres. Belt 130 has sieve parts as shown in Figure 2. Each sieve part may have a width of at least 237 microns, and preferably at least 475 microns, and an area of at least three times, and preferably greater than four times, the area of an aperture in the apertured member. The sieve parts may form at least 20%, and preferably at least 30% of the total area of the support member. The apertures may have a width of at least 95 microns, and a patch at least three times their width. The smallest width of the solid part of the supporting member may be at least equal to the width of the apertures. The sieve parts may comprise, Fig. 5, a woven screen e.g. of wire nylon or glass fibre, in which strands 51 are straight and strands 52 weave over and under strands 51. The bends 53 in woven strands 52 form troughs extending parallel to strands 51, and troughs extending parallel to strands 52. The depth of each trough is preferably at least 28.5 microns. A non-woven web produced by the apparatus of Figure 1 comprises dense fibre areas in a pattern corresponding to that of the drum sieve parts 19 and interconnected by aligned fibres in a pattern corresponding to that of the solid drum part 20. A pattern of bundled fibres corresponding to the pattern of apertures 31 in belt 30 subdivides the dense fibre areas. When the sieve parts are formed by the screen shown in Figure 5, the troughs defined by the strand bends produce fibre bundles which sub-divide areas of low fibre density within the dense fibre areas. The starting material comprises a carded or an air-laid web, or a web formed by liquid deposition. The fibres may be natural, mineral or synthetic and are preferably 0.25 to 2.5 inches long. The redistribution of webs of viscose rayon fibres is exemplified. |
