Method for manufacture of a non-woven fibrous web
First Claim
1. A method for making a non-woven fibrous web from a foamed fiber furnish wherein said furnish is distributed on a moving foraminous support from a pressurized headbox which comprises:
- a. forming a foamed fiber furnish containing 0.3 to 1.2 weight percent fibers by dispersing fibers in foamed liquid from step d comprising water and a surface active agent and containing 55 to 75 percent air by volume;
b. supplying said foamed fiber furnish from step a comprising said foamed liquid to said headbox and onto said foraminous support without further foam generation treatment with the production of a non-woven fibrous web and simultaneous regeneration of foamed liquid passing through said support by entrainment of additional amounts of air therein;
c. collecting said regenerated foamed liquid after passing through said support, said regenerated foamed liquid containing from about 55 to about 75 percent air by volume; and
d. returning collected foamed liquid from step c directly to step a as the source of foamed liquid for the preparation of said foamed fiber furnish.
3 Assignments
0 Petitions
Accused Products
Abstract
Apparatus and method for the manufacture of a non-woven fibrous web such as paper from a dispersion of fibers in a foamed liquid in which fiber furnished in a foamed liquid comprising a solution of surfactant in water is discharged from a headbox into the nip of a twin forming wire prior to its passage over a forming roll. The water-surfactant solution is drained from the web and recycled as a foamed liquid containing about 65% air in the form of bubbles of from about 20 to about 200 microns in diameter. The foamed liquid is directed into a mix tank wherein a slurry containing fiber at 20% to 55% solids is added and mixed. The mixture is pumped to the headbox and into the nip of the forming wires.
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Citations
7 Claims
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1. A method for making a non-woven fibrous web from a foamed fiber furnish wherein said furnish is distributed on a moving foraminous support from a pressurized headbox which comprises:
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a. forming a foamed fiber furnish containing 0.3 to 1.2 weight percent fibers by dispersing fibers in foamed liquid from step d comprising water and a surface active agent and containing 55 to 75 percent air by volume; b. supplying said foamed fiber furnish from step a comprising said foamed liquid to said headbox and onto said foraminous support without further foam generation treatment with the production of a non-woven fibrous web and simultaneous regeneration of foamed liquid passing through said support by entrainment of additional amounts of air therein; c. collecting said regenerated foamed liquid after passing through said support, said regenerated foamed liquid containing from about 55 to about 75 percent air by volume; and d. returning collected foamed liquid from step c directly to step a as the source of foamed liquid for the preparation of said foamed fiber furnish. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of starting up a system for making non-woven fibrous webs from a foamed fiber furnish comprising fibers dispersed in an aqueous foam containing from about 55 to about 75 percent air by volume which comprises:
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a. preparing a foamable liquid comprising water and a surface active agent; b. passing said foamable liquid from step a substantially free from fibers to and through a moving foraminous support web-forming means whereby foam is produced in said liquid by entrainment of air therein producing a foamed liquid; c. collecting foamed liquid passing through said foraminous support; d. recirculating said collected foamed liquid from step c to and through said foraminous support until said foamed liquid contains from about 55 to about 75 percent air by volume and is capable of supporting and transporting fibers as a dispersion therein; e. forming a foamed fiber furnish by dispersing fibers in said foamed liquid from step d; and f. supplying said foamed fiber furnish to said foraminous support for the production of said non-woven fibrous web.
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Specification