Other

Mitsubishi Heavy Industries Limited

Metso Paper Inc.

Beloit Technologies, Inc.

Kimberly-clark Worldwide, Inc.

Beloit Corporation

Roger A Kanitz

Thomas D Rogers

Michael Alan Hermans

Frank Stephen Hada

Robert Lewis Clarke

Charles Robert Tomsovic

David V Lange

Patrick W Murry

Richard D Hauser

Doug A Rounds

Daniel J Eaton

Lowell Everett Thoms

Brian Wade Isenhart

A web of tissue is formed in a twin wire former, followed by an air press for water removal in the pressing section, passing onto a Yankee dryer. A headbox injects stock between upper and lower dryer fabrics brought together on a breast roll. The fabrics moves over vacuum boxes, and the web is heated with steam and passed between an upper pressure box and a lower vacuum box forming an air press which dewaters the web. A sheet transfer pickup vacuum box holds the sheet to the upper fabric as the lower fabric diverges from the upper fabric. A pressure roller transfers the web onto a Yankee dryer. The fabrics are cleaned on vertical runs before returning to the breast roll. A final forming fabric is arranged to operated at a lower speed than the penultimate forming fabric so that a rush transfer and creping like action takes place.

Papermaking machine for forming tissue employing an air press

A web of tissue is formed in a twin wire former, followed by an air press for water removal in the pressing section, passing onto a Yankee dryer. A headbox injects stock between upper and lower dryer fabrics brought together on a breast roll. The fabrics move over vacuum boxes, and the web is heated with steam and passed between an upper pressure box and a lower vacuum box forming an air press which dewaters the web. A sheet transfer pickup vacuum box holds the sheet to the upper fabric as the lower fabric diverges from the upper fabric. A pressure roller transfers the web onto a Yankee dryer. The fabrics are cleaned on vertical runs before returning to the breast roll.

A web of tissue is formed in a crescent former, followed by an air press for water removal in the pressing section, passing onto a Yankee dryer. A headbox injects stock between upper and lower dryer fabrics brought together on a breast roll. The fabrics move over vacuum boxes, and the web is heated with steam and passed between an upper pressure box and a lower vacuum box forming an air press which dewaters the web. A sheet transfer pickup vacuum box holds the sheet to the upper fabric as the lower fabric diverges from the upper fabric. A pressure roller transfers the web onto a Yankee dryer. The fabrics are cleaned on vertical runs before returning to the breast roll. A second upper fabric or transfer fabric operating at a lower speed then the first can be used to form a rush transfer between the forming fabrics and the Yankee dryer which increases web bulk and absorbency. Instead of a second fabric, a vacuum pressure roll may perform the rush transfer between the lower forming fabric and the Yankee dryer. The lower fabric may be divided into two fabrics, and the second fabric which passes through the air press, can be used to mold a texture into the web. The rush transfer and the molding fabric may be combined in one machine. A twin wire former may be used instead of a crescent former in each of the above configurations.

A pressurized box is positioned opposite a vacuum box. The pressurized box has a leading cross machine direction baffle with a ceramic shoe which engages a forming fabric, and a trailing cross machine direction baffle of similar construction. Two end deckles complete the pressurized box. The leading cross machine direction baffle presses against a resilient seal which causes a web contained between upper and lower forming fabrics to wrap about the baffle shoe a few degrees forming an effective end seal which does not allow air to bypass the baffle. The trailing cross machine direction baffle is positioned over a vacuum box which prevents air from leaking around the trailing baffle. A vacuum box draws air through the forming fabrics and the web, from the pressurized box increasing the total pressure gradient across the web to 20 to 30 psi or more. The pressure box and opposed vacuum box form an air press. The pressure box is positioned and held against the forming fabrics by opposing air tubes. An alternative embodiment utilizes a suction roll positioned beneath the pressure box and having a suction gland positioned beneath the portion of the roll which backs the pressure box.

Air press

An air press for noncompressively dewatering a wet web to consistency levels not previously thought possible at industrially useful speeds without thermal dewatering.

Air press for dewatering a wet web

An air press for noncompressively dewatering a wet web to consistency levels not previously thought possible at industrially useful speeds without thermal dewatering. The air press has an air plenum and a vacuum collection device, each on opposite sides of two support fabrics that sandwich the paper web. There are cross machine sealing blade(s) that impinge upon the support fabrics and is opposed on the other side of the support fabrics by a sealing member formed of deformable material. The air plenum and vacuum collection device are movable relative to one another so that the sealing blade and deformable sealing member form a seal in the operating position of the air press.

A method and apparatus for improved dewatering of a papermaking stock in a web forming section of a papermaking machine including directing a stock jet stream into the head end of a run between opposed looped forming wires traveling in a substantially parallel forming run passing over a curved vacuum forming box and thereafter passing over one or more pressure locations with a pressure dome on one side and a water collecting chamber at the other side of the wires with the pressure dome in one form divided into compartments each applying an increasing pressure to the wire and stock between the wires with the air pressure being heated such as by being delivered from the dryer section and the wires separated slightly following the pressure location with a last smaller pressure compartment transferring the web to one of the wires and the wire carrying the web thereafter turning over a couch roll and the other wire carried over a turning roll.

Twin wire paper forming section with heated air pressure domes

In a papermaking machine, a method and mechanism for delivering stock to a dewatering web including a pressure headbox with a narrowing slice opening, a receiving throat either with a single traveling forming wire or a pair of traveling forming wires, bridging the space between the headbox opening and the wire so that the stock jet is contained without a free surface, and applying a trailing flexible element opposite the stock in a single wire machine or against one wire in a twin wire machine with the force and location of the trailing element controlled by a series of push rods arranged parallel in a cross machine direction.

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Beloit, WI, United States of America

Roger A Kanitz