| 摘要 |
A method and apparatus for forming an air-laid web (60) of dry fibres suitable for use in a wide variety of products ranging from bath and facial tissues having basis weights on the order of 13 lbs./2880 ft.<2> to 18lbs./2880 ft.<2> to products having basis weights on the order of 19 lbs./2880 ft.<2> to 40 lbs./2880 ft.<2>, or even heavier, on a high-speed production basis, yet wherein the web produced, irrespective of basis weight, is characterised by random array of individualised fibres substantially undamaged by mechanical action and having a controlled cross-directional profile, and by its freedom from nits, pills, rice and the like, thereby improving both the appearance and the tensile strength of the web. The apparatus includes a 2-dimensional flow control and flbre screening system and a forming chamber (79) wherein a) substantially no cross-flow forces are created at the fibre feeding, screening and forming stages so as to ensure that the cross-directional profile of the web produced is controlled within desired limits and permitting formation of high-quality webs of virtually any desired width; b) the fibres are subjected to only minimal mechanical disintegrating action at all stages of the process subsequent to hammermilling, and, thus, shortening, curling and/or rolling of the fibres into pills, rice, or nits is minimized and, to the fullest extent possible, eliminated. Those pills, rice, nits and/or aggregated fibre masses present in the fibre stream fed to and/or through the flow control and fibre screening system are preferably centrifugally and tangentialiy seperated from individualised fibres and soft fibre flocs across the full width of the apparatus.
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