초록 ▼

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 a preferred embodiment, a solution of surfactant in water is initially discharged from a headbox into the nip of a twin forming wire prior to its passage over a curv

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 a preferred embodiment, a solution of surfactant in water is initially discharged from a headbox into the nip of a twin forming wire prior to its passage over a curvilinear path defined by a forming roll. The water-surfactant solution is caused repeatedly to pass through the outer one of the twin forming wires until there is created, and stored in a silo, 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 from the silo into a mix tank wherein a slurry containing fibers at 20% to 55% solids is added and mixed. The mixture is pumped to the headbox and into the nip of the forming wires. The outer wire retains the fibers while passing and again foaming the liquid for return to the silo and the mix tank for addition of fibers and return to the headbox. The process is continued in formation of a fibrous web. In an alternative embodiment, the curvilinear path is defined by an arcuate surface that is fluid pervious so that the solution to be foamed may pass through both the inner and outer wires. A further alternative embodiment utilizes a single forming wire for receiving the solution prior to passage over a suction breast roll which receives the solution then centrifuges it outwardly in formation of foamed liquid.

대표청구항 ▼

A method for making up a foamed fiber furnish for the production of non-woven fibrous web on a moving foraminous support which comprises: a. preparing a foamable liquid comprising water and a surface active agent; b. passing said foamable liquid in the substantial absence of fibers to and through sa

A method for making up a foamed fiber furnish for the production of non-woven fibrous web on a moving foraminous support which comprises: a. preparing a foamable liquid comprising water and a surface active agent; b. passing said foamable liquid in the substantial absence of fibers to and through said moving foraminous support web forming means whereby foam is formed in said liquid by entrainment of air therein producing a foamed liquid; c. collecting foamed liquid passing through said foraminous support; d. storing said collected foamed liquid for a period of time sufficient to permit said foamed liquid to stratify into an upper frothy layer and a lower more dense layer of foamed liquid; e. recirculating said more dense layer of said foamed liquid to and through said foraminous support until said more dense layer of said stored 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; f. forming a foamed fiber furnish by dispersing fibers in said foamed liquid from step (e); and g. supplying said foamed fiber furnish to said foraminous support for the production of said non-woven fibrous web.