| 摘要 |
<p>677,928. Lap-forming apparatus; openers &c. JOHNSON & JOHNSON (GREAT BRITAIN), Ltd. Feb. 23, 1950. [Feb. 23, 1949], No. 4726/50. Class 120(i) A substantially isotropic fibrous web for the manufacture of non-woven fabric is produced by inducing turbulence into an air stream, continuously and progressively removing fibres from the advancing edge of a feed of fibres and introducing them into the turbulent air stream downstream of the place where turbulence has been induced, subsequently stopping the movement of the fibres in the direction of the air flow whilst permitting the air stream to continue so as to produce a web, and then removing the web from the air stream. As shown, a web 26 of longitudinally aligned fibres, in the form of a corded web or an assembly of cord slivers, is fed by a roll 30 to a rotary lickerin-type combing roll 34 which rakes the fibres individually from the feed web and doffs them centrifugally into an air stream in a conduit 10. Air is drawn through conduit 10 by a fan 18 and is rendered turbulent by passing through a restricted inlet 40 into a diffusion chamber at the entrance to the conduit. The depth of the conduit is reduced towards the fibre feed point to give improved uniformity of air flow. The air velocity at the fibre feed point may be greater than the peripheral speed of roll 34, to aid the doffing of fibres from the roll. The depth of the conduit increases towards a rotary screen 22 on which the fibres are deposited and by which they are removed from the air stream in the form of an isotropic web 24. To avoid thin selvedges being formed on web 24, the side walls of conduit 10, between the fibre feed and the screen, may be provided with narrow baffles which produce local turbulence along the side walls and cause the air flow at the walls to be uniform with that at the conduit centre. Specification 674,779 is referred to.</p> |
