GB1219921A - Method and apparatus for pneumatically or hydraulically depositing a non-woven web structure - Google Patents

Abstract

1,219,921. Producing non-woven web structures. MONSANTO CO. 22 Jan., 1968 [27 Jan., 1967], No. 3265/68. Heading B5B. [Also in Division D1] A multifilament strand is deposited on a travelling collection surface in a randomly dispersed manner to produce a non-woven filamentary web structure having uniform thickness by extruding a fibre-forming material through a multiplicity of orifices to form a multifilament strand, advancing the strand through a combined aspirator and traversing means and on to the collecting surface with a high velocity jet or stream of fluid and alternately diverting the direction of travel of the strand toward one side of the web on the collecting surface and then to the other with a jet or stream of fluid at a velocity which is less than the velocity of the fluid advancing the strand. As shown in Figs. 2, 3 and 4, the combined aspirating and traversing mechanism comprises a housing body 10 containing an annular chamber 12 and a diverging cavity 13 interconnected by a passageway 14. The chamber 12 has a closure 15 provided with a hollow stem 16 extending to within close proximity of the entrance to the passageway 14. An element 17 concentrically disposed about the stem 16 has a plurality of passageways 25. The bottom portion of chamber 12 is flared to provide chamber 18 between element 17 and passageway 14. The closure cap 15 is provided with a passageway 22 which is in alignment with passageway 14 for receiving a multifilament strand 24. The aspirating medium, which may be a pressurized gas or liquid, is introduced into chamber 12 by means of pipe 26 and hole 27 and flows through the passageways 25 of element 17 into the chamber 18. In this chamber the high velocity fluid engages strand 24 with sufficient energy to draw the strand and forward it through the passageway 14 into the traversing zone of the apparatus which is the diverging cavity 13. Traversing of the strand 24 is accomplished by supplying a low-pressure fluid medium to the cavity 13 alternately through pipe 30 and port 28 and pipe 31 and port 29. The alternation of the supply of the medium may be effected by means of a programmed rotating valve of known type. As shown in Fig. 1, the combined aspirator and traverse assembly 40 is located in a fixed position above the foraminous endless travelling belt 32 mounted on rolls 33 to 35. A suction box 36 is provided immediately below belt 32 and the line of traverse to insure that the randomly dispersed filaments retain their respective positions after deposition.