Controlled forming wire separation on impervious roll of twin-wire papermaking machine

Claim 1

A mechanism for continuously forming a fibrous web from a slurry of stock comprising in combination: a first looped permeable woven outer forming wire; a second looped permeable woven inner forming wire; said wires positioned to form a converging throat leading to a forming run wherein the wires press against a web being formed therebetween; a headbox having an opening positioned to direct a stream of stock into said throat; guide rolls within each of the wire loops holding the loops in tension so that the outer wire applies a pressing force to press the stock between the wires in said forming run; a convexly curved surface within the second wire with the first and second wires wrapping said surface along said forming run; a first off running guide means for said first wire positioned following the forming run and separating the first wire from the second wire at a first separation point on said curved surface; and a second off running guide means for said second wire following said forming zone and separating the second wire from said surface at a second separation point immediately following the first separation point with the web following the second wire;

Claim 12

THE METHOD OF CONTINUOUSLY FORMING A FIBROUS WEB FROM A SLURRY OF STOCK WHICH COMPRISES: PASSING A PAIR OF LOOPED PERFORATE WOVEN TENSIONED FORMING WIRES THROUGH AN ARCUATE FORMING RUN OVER AN ARCUATE SURFACE TO APPLY A FORCE NORMAL TO A WEB BEING FORMED THEREBETWEEN TO DEWATER THE WEB; DELIBERING A STREAM OF FIBROUS STOCK TO THE UPSTREAM END OF SAID FORMING RUN; SEPARATING THE OUTER WIRE FROM THE INNER WIRE AT A FIRST SEPARATION POINT WHILE TRAVELING THROUGH SAID ACUATE RUN AND SEPARATING THE INNER WIRE FROM THE INNER WIRE FROM SAID RUN SEPARATION POINT IMMEDIATELY AFTER SAID FIRST POINT; AND BLOCKING THE INNER SURFACE OF THE INNER WIRE SO THAT FLUID IS PREVENTED FROM FLOWING OUTWARDLY AT SAID SEPARATION POINT SO THAT THE WEB FOLLOWS SAID INNER WIRE.

Claim 13

THE METHOD OF CONTINUOUSLY FORMING A FIBROUS WEB FROM A SLURRY OF STOCK WHICH COMPRISES: PASSING A PAIR OF LOOPED PERFORATE WOVEN TENSIONED FORMING WIRES THROUGH AN ARCUATE FORMING RUN OVER AN ARCUATE SURFACE TO APPLY A FORCE NORMAL TO A WEB BEING FORMED THEREBETWEEN TO DEWATER THE WEB; DELIBERING A STREAM OF FIBROUS STOCK TO THE UPSTREAM END OF SAID FORMING RUN; SEPARATING THE OUTER WIRE FROM THE INNER WIRE AT A FIRST SEPARATION POINT WHILE TRAVELING THROUGH SAID ACUATE RUN AND SEPARATING THE INNER WIRE FROM THE INNER WIRE FROM SAID RUN SEPARATION POINT IMMEDIATELY AFTER SAID FIRST POINT; AND BLOCKING THE INNER SURFACE OF THE INNER WIRE SO THAT FLUID IS PREVENTED FROM FLOWING OUTWARDLY AT SAID SEPARATION POINT SO THAT THE WEB FOLLOWS SAID INNER WIRE.

Claim 17

The method of continuously forming a fibrous web from a slurry of stock which comprises: guiding a pair of looped perforate woven forming wires under tension through an arcuate forming run over an imperforate rotating roll to apply a force normal to the web being formed therebetween to press water from the web into the space between the inner wire and the roll within interstices of the wire and through the outer wire so that water is thrown therefrom; delivering a stream of fibrous stock slurry to the upstream end of the forming run; and separating the outer wire from the inner wire lifting it off of the curved arcuate path on the roll while maintaining the inner wire on the roll so that the web remains pasted thereto and immediately thereafter lifting the inner wire off the roll so that the separation of the wires from each other and the inner wire from the roll generates an inward surge of air through the outer wire to clean fibers from the outer wire left thereon from dewatering through the outer wire.

Claim 18

The method of continuously forming a fibrous web from a slurry of stock which comprises: guiding a pair of looped perforate woven forming wires under tension through an arcuate forming run over an imperforate rotating roll to apply a force normal to the web being formed therebetween to press water from the web into the space between the inner wire and the roll within interstices of the wire and through the outer wire so that water is thrown therefrom; delivering a stream of fibrous stock slurry to the upstream end of the forming run; and separating the outer wire from the inner wire lifting it off of the curved arcuate path on the roll while maintaining the inner wire on the roll so that the web remains pasted thereto and immediately thereafter lifting the inner wire off the roll so that the separation of the wires from each other and the inner wire from the roll generates an inward surge of air through the outer wire to clean fibers from the outer wire left thereon from dewatering through the outer wire.