MANUFACTURE OF FIBROUS WEB STRUCTURES

摘要

1452365 Air laying fiber webs;non-woven fabrics CONWED CORP 3 Oct 1974 [19 Oct 1974] 42996/74 Headings D1N and D1R A fibrous structure is formed by projecting an air-fiber stream onto a support through which air is passed, the distance of a projection nozzle from the support being such that it lies between the lines Y = X2/20 and Y = X2/135 on the graph shown in Fig. 6, the symbols and equations being as specified in Fig. 6. Fibers are separated in a hammer mill 10 and supplied by a fan F to a cyclone separator 20 in which excess air 26 is removed, the air/fiber mixture of the desired proportions than being fed by fan 30 to the nozzle 44. Nozzle 44 is of narrow rectangular cross-section, Fig. 2, not shown, but may be of circular section in which case a rectangular nozzle of equivalent area is considered in order to determine the position on the graph of Fig. 6. A liquid or solid binder such as starch, acrylic, styrene, vinyl chloride, polyolefine or polyester resins or thermosetting resins e.g. phenolic ureaformaldehyde, melamine formaldehyde or some epoxy resins, each in powdered form may be sprayed by jets 70 into the fiber/air stream, or fed directly into the hammer mill 10. In the case of a circular nozzle a jet 70 may be centrally located. At least half of the fibers are preferably less than 0.25 inches long and fibers such as cotton rayon kapok, wool and wood are referred to and additives such as mineral fibers may be included. Also solid or liquid additives may be incorporated such as dyes, fire retardants or seeds for grass or vegetables.