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US6083346A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of dewatering wet web using an integrally sealed air press

Assignee: Kimberly Clark Worldwide Inc
•
Filing: 1997-10-31
•
Granted: 2000-07-04
•
Expires: 2017-10-31
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Abstract

Abstract A tissue sheet is made using a modified wet pressing process employing an integrally sealed air press. After initial formation and conventional vacuum dewatering, the wet web is conformed to the surface contour of a relatively coarse fabric to give the web a textured surface. By creating a pressure differential across the web of at least 30 inches of mercury and an air stream through the web of at least 500 SCFM/in2, the air press noncompressively dewaters the wet web to a consistency of about 30 to about 40 percent prior to a Yankee dryer. The web is dried to substantially preserve its three-dimensional, throughdried-like texture. The resulting web has an exceptionally high degree of bulk and absorbency not previously found in wet-pressed products.

Inventors

  • 👤 Michael Alan Hermans
  • 👤 Shan Liang-Chen
  • 👤 Fung-Jou Chen
  • 👤 Frank Gerald Druecke
  • 👤 Robert Irving Gusky
  • 👤 Frank Stephen Hada
  • 👤 Richard Joseph Kamps
  • 👤 Charles Robert Tomsovic

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 18:13
CPC Classifications
D; D21; D21F; D21F11/00; D21F11/14; D21F11/145; D21F1/00; D21F1/48; D21F1/52; D21F11/006; D21F3/00; D21F3/02

Claims Analysis

Total Claims: 68
Claim 1
Independent Claim 148 words
A method for making a cellulosic web comprising the steps of: a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; b) dewatering said wet web to a consistency of at least about 30 percent using a noncompressive dewatering device that is adapted to create a pressure differential across said wet web is at least about 30 inches of mercury and to cause a pressurized fluid at greater than 10 pounds per square inch gauge to flow substantially through said wet web due to an integral seal formed with said wet web; c) transferring said wet web to a molding fabric to give said wet web a molded structure; d) pressing said dewatered and molded web against a surface of a heated drying cylinder to at least partially dry said web; and e) drying said web to a final dryness.
Claim 2
Independent Claim 148 words
A method for making a cellulosic web comprising the steps of: a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; b) dewatering said wet web to a consistency of at least about 30 percent using a noncompressive dewatering device that is adapted to create a pressure differential across said wet web is at least about 30 inches of mercury and to cause a pressurized fluid at greater than 10 pounds per square inch gauge to flow substantially through said wet web due to an integral seal formed with said wet web; c) transferring said wet web to a molding fabric to give said wet web a molded structure; d) pressing said dewatered and molded web against a surface of a heated drying cylinder to at least partially dry said web; and e) drying said web to a final dryness.
Claim 3
Dependent Claim 28 words
The method of claim 1 wherein said consistency of said wet web is increased by said noncompressive dewatering device by between about 5 percent to about 20 percent.
Claim 4
Dependent Claim 24 words
The method of claim 1 wherein the pressure differential across said wet web is from between about 35 to about 60 inches of mercury.
Claim 5
Dependent Claim 22 words
The method of claim 1 wherein said pressurized fluid is pressurized to between 10 to about 30 pounds per square inch gauge.
Claim 6
Dependent Claim 27 words
The method of claim 1 wherein said collection device includes a vacuum box that draws a vacuum of greater than 0 to about 25 inches of mercury.
Claim 7
Dependent Claim 25 words
The method of claim 1 wherein said wet web travels at a speed of at least about 2000 feet per minute through said air press.
Claim 8
Dependent Claim 25 words
The method of claim 1 wherein said pressurized fluid used to dewater said wet web has a temperature of about 300 degrees Celsius or less.
Claim 9
Dependent Claim 25 words
The method of claim 7 wherein said pressurized fluid used to dewater said wet web has a temperature of about 150 degrees Celsius or less.
Claim 10
Dependent Claim 22 words
The method of claim 1 wherein said wet web is transferred to said heated drying cylinder by a pair of transfer rolls.
Claim 11
Dependent Claim 21 words
The method of claim 9 wherein one or both of said transfer rolls are not loaded against said heated drying cylinder.
Claim 12
Dependent Claim 20 words
The method of claim 9 wherein one or both of said transfer rolls are loaded against said heated drying cylinder.
Claim 13
Dependent Claim 29 words
The method of claim 1 wherein said wet web is pressed against said heated drying cylinder with a pressing pressure of less than about 350 pounds per lineal inch.
Claim 14
Dependent Claim 20 words
The method of claim 1 wherein the flow of said pressurized fluid transfers said wet web to said molding fabric.
Claim 15
Dependent Claim 16 words
The method of claim 1 wherein said wet web is rush transferred onto said molding fabric.
Claim 16
Dependent Claim 27 words
The method of claim 1 wherein said web is dried to a consistency of at least about 95 percent before being creped from said heated drying cylinder.
Claim 17
Dependent Claim 46 words
The method of claim 1 wherein said wet web is partially dried to a consistency of from between about 40 to about 80 percent on said heated drying cylinder and is then dried to a final dryness having a consistency of at least about 95 percent.
Claim 18
Independent Claim 186 words
A method for making a cellulosic web comprising the steps of: a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; b) dewatering said wet web to a consistency of from between about 10 percent to about 30 percent; c) further dewatering said wet web to a consistency of from between about 30 to about 40 percent using an air press that is adapted to cause at least about 85 percent of a pressurized fluid at at least 15 pounds per square inch gauge to flow through said wet web due to an integral seal formed between an air plenum and a collection device; d) transferring said wet web to a molding fabric to give said wet web a molded structure and a bulk of at least about 8 cubic centimeters per gram; e) pressing said dewatered and molded web against a surface of a heated drying cylinder with said molding fabric to preserve said molded structure and said bulk of at least about 8 cubic centimeters per gram; and f) drying said web to a final dryness.
Claim 19
Independent Claim 186 words
A method for making a cellulosic web comprising the steps of: a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; b) dewatering said wet web to a consistency of from between about 10 percent to about 30 percent; c) further dewatering said wet web to a consistency of from between about 30 to about 40 percent using an air press that is adapted to cause at least about 85 percent of a pressurized fluid at at least 15 pounds per square inch gauge to flow through said wet web due to an integral seal formed between an air plenum and a collection device; d) transferring said wet web to a molding fabric to give said wet web a molded structure and a bulk of at least about 8 cubic centimeters per gram; e) pressing said dewatered and molded web against a surface of a heated drying cylinder with said molding fabric to preserve said molded structure and said bulk of at least about 8 cubic centimeters per gram; and f) drying said web to a final dryness.
Claim 20
Dependent Claim 24 words
The method of claim 17 wherein said wet web is dewatered to a consistency of from between about 32 percent to about 40 percent.
Claim 21
Dependent Claim 23 words
The method of claim 18 wherein said web is dewatered to a consistency of from between about 34 percent to about 40 percent.
Claim 22
Dependent Claim 21 words
The method of claim 17 wherein the pressure differential across said wet web is at least about 30 inches of mercury.
Claim 23
Dependent Claim 24 words
The method of claim 20 wherein the pressure differential across said wet web is from between about 35 to about 60 inches of mercury.
Claim 24
Dependent Claim 23 words
The method of claim 17 wherein said wet web has a dwell time in said air press of about 10 milliseconds or less.
Claim 25
Dependent Claim 23 words
The method of claim 22 wherein said wet web has a dwell time in said air press of about 7.5 milliseconds or less.
Claim 26
Dependent Claim 46 words
The method of claim 17 wherein said wet web travels at a speed of at least about 1000 feet per minute through said air press and said wet web is dewatered to a consistency which increases by at least about 5 percent in said air press.
Claim 27
Dependent Claim 25 words
The method of claim 17 wherein said wet web travels at a speed of at least about 2000 feet per minute through said air press.
Claim 28
Dependent Claim 24 words
The method of claim 17 wherein at least about 90 percent of said pressurized fluid in said air plenum flows through said wet web.
Claim 29
Dependent Claim 32 words
The method of claim 17 wherein said heated drying cylinder includes a dryer hood and said molding fabric separates from said wet web prior to said wet web entering said dryer hood.
Claim 30
Dependent Claim 30 words
The method of claim 17 wherein said molding fabric wraps said drying cylinder for less than the full distance that said wet web is in contact with said drying cylinder.
Claim 31
Dependent Claim 15 words
The method of claim 17 wherein a release agent is added to said molding fabric.
Claim 32
Dependent Claim 17 words
The method of claim 17 wherein said web is removed from said heated drying cylinder without creping.
Claim 33
Dependent Claim 22 words
The method of claim 17 wherein said pressurized fluid is pressurized to between 15 to about 30 pounds per square inch gauge.
Claim 34
Dependent Claim 27 words
The method of claim 17 wherein said collection device includes a vacuum box that draws a vacuum of greater than 0 to about 25 inches of mercury.
Claim 35
Dependent Claim 25 words
The method of claim 17 wherein said wet web travels at a speed of at least about 2000 feet per minute through said air press.
Claim 36
Dependent Claim 25 words
The method of claim 17 wherein said pressurized fluid used to dewater said wet web has a temperature of about 300 degrees Celsius or less.
Claim 37
Dependent Claim 22 words
The method of claim 17 wherein said wet web is transferred to said heated drying cylinder by a pair of transfer rolls.
Claim 38
Dependent Claim 29 words
The method of claim 17 wherein said wet web is pressed against said heated drying cylinder with a pressing pressure of less than about 350 pounds per lineal inch.
Claim 39
Dependent Claim 20 words
The method of claim 17 wherein the flow of said pressurized fluid transfers said wet web to said molding fabric.
Claim 40
Dependent Claim 16 words
The method of claim 17 wherein said wet web is rush transferred onto said molding fabric.
Claim 41
Dependent Claim 27 words
The method of claim 17 wherein said web is dried to a consistency of at least about 95 percent before being creped from said heated drying cylinder.
Claim 42
Dependent Claim 46 words
The method of claim 17 wherein said wet web is partially dried to a consistency of from between about 40 to about 80 percent on said heated drying cylinder and is then dried to a final dryness having a consistency of at least about 95 percent.
Claim 43
Independent Claim 184 words
A method for making a cellulosic web comprising the steps of: a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; b) sandwiching said wet web between a pair of fabrics to form a wet web structure, at least one of said fabrics being a three-dimensional molding fabric; c) passing said wet web structure between an air plenum and a collection device with said three-dimensional molding fabric disposed between said wet web and said collection device, said air plenum and said collection device being operatively associated and adapted to create a pressure differential across said wet web structure of at least about 30 inches of mercury and direct a stream of pressurized fluid through said wet web structure of at least about 10 standard cubic feet per minute per square inch; d) dewatering said wet web using said stream of pressurized fluid to a consistency of at least about 30 percent; e) pressing said dewatered web against a surface of a heated drying cylinder with a fabric; and f) drying said web to a final dryness.
Claim 44
Independent Claim 184 words
A method for making a cellulosic web comprising the steps of: a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; b) sandwiching said wet web between a pair of fabrics to form a wet web structure, at least one of said fabrics being a three-dimensional molding fabric; c) passing said wet web structure between an air plenum and a collection device with said three-dimensional molding fabric disposed between said wet web and said collection device, said air plenum and said collection device being operatively associated and adapted to create a pressure differential across said wet web structure of at least about 30 inches of mercury and direct a stream of pressurized fluid through said wet web structure of at least about 10 standard cubic feet per minute per square inch; d) dewatering said wet web using said stream of pressurized fluid to a consistency of at least about 30 percent; e) pressing said dewatered web against a surface of a heated drying cylinder with a fabric; and f) drying said web to a final dryness.
Claim 45
Dependent Claim 24 words
The method of claim 41 wherein at least about 85 percent of said pressurized fluid in said air plenum flows through said wet web.
Claim 46
Dependent Claim 24 words
The method of claim 43 wherein at least about 90 percent of said pressurized fluid in said air plenum flows through said wet web.
Claim 47
Dependent Claim 22 words
The method of claim 41 wherein said pressurized fluid is pressurized to between 10 to about 30 pounds per square inch gauge.
Claim 48
Dependent Claim 27 words
The method of claim 41 wherein said collection device includes a vacuum box that draws a vacuum of greater than 0 to about 25 inches of mercury.
Claim 49
Dependent Claim 23 words
The method of claim 41 wherein said wet web has a dwell time in said air press of about 10 milliseconds or less.
Claim 50
Dependent Claim 46 words
The method of claim 41 wherein said wet web travels at a speed of at least about 1000 feet per minute through said air press and said wet web is dewatered to a consistency which increases by at least about 5 percent in said air press.
Claim 51
Dependent Claim 25 words
The method of claim 41 wherein said wet web travels at a speed of at least about 2000 feet per minute through said air press.
Claim 52
Dependent Claim 25 words
The method of claim 41 wherein said pressurized fluid used to dewater said wet web has a temperature of about 300 degrees Celsius or less.
Claim 53
Dependent Claim 32 words
The method of claim 41 wherein said heated drying cylinder includes a dryer hood and said molding fabric separates from said wet web prior to said wet web entering said dryer hood.
Claim 54
Dependent Claim 30 words
The method of claim 41 wherein said molding fabric wraps said drying cylinder for less than the full distance that said wet web is in contact with said drying cylinder.
Claim 55
Dependent Claim 22 words
The method of claim 41 wherein said wet web is transferred to said heated drying cylinder by a pair of transfer rolls.
Claim 56
Dependent Claim 15 words
The method of claim 41 wherein a release agent is added to said molding fabric.
Claim 57
Dependent Claim 17 words
The method of claim 41 wherein said web is removed from said heated drying cylinder without creping.
Claim 58
Dependent Claim 27 words
The method of claim 41 wherein said web is dried to a consistency of at least about 95 percent before being creped from said heated drying cylinder.
Claim 59
Dependent Claim 46 words
The method of claim 41 wherein said wet web is partially dried to a consistency of from between about 40 to about 80 percent on said heated drying cylinder and is then dried to a final dryness having a consistency of at least about 95 percent.
Claim 60
Independent Claim 233 words
A method for making a cellulosic web comprising the steps of: a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; b) covering said wet web with a support fabric to form a wet web structure; c) transporting said wet web structure through an air press, said air press including an air plenum and a collection device which are operatively associated with each other and adapted to create a pressure differential across said wet web structure, said air plenum and said collection device cooperating with said wet web structure to form an integral seal therewith; d) passing a stream of pressurized fluid of at least about 5 psig and having a volume of at least about 10 standard cubic feet per minute per square inch through said wet web structure from said air plenum to said collection device and creating a vacuum in said collection device of at least about 10 inches of mercury to cause a pressure differential across said wet web structure of at least about 25 inches of mercury, said pressure differential noncompressively dewatering said wet web to a consistency of at least about 25 percent; e) transferring said dewatered web to a third fabric; and f) pressing said dewatered web against at least a portion of a heated drying cylinder using said third fabric to a obtain a desired final dryness.
Claim 61
Independent Claim 233 words
A method for making a cellulosic web comprising the steps of: a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; b) covering said wet web with a support fabric to form a wet web structure; c) transporting said wet web structure through an air press, said air press including an air plenum and a collection device which are operatively associated with each other and adapted to create a pressure differential across said wet web structure, said air plenum and said collection device cooperating with said wet web structure to form an integral seal therewith; d) passing a stream of pressurized fluid of at least about 5 psig and having a volume of at least about 10 standard cubic feet per minute per square inch through said wet web structure from said air plenum to said collection device and creating a vacuum in said collection device of at least about 10 inches of mercury to cause a pressure differential across said wet web structure of at least about 25 inches of mercury, said pressure differential noncompressively dewatering said wet web to a consistency of at least about 25 percent; e) transferring said dewatered web to a third fabric; and f) pressing said dewatered web against at least a portion of a heated drying cylinder using said third fabric to a obtain a desired final dryness.
Claim 62
Dependent Claim 32 words
The method of claim 57 wherein said stream of pressurized fluid is of at least about 10 psig passing through said wet web structure from said air plenum to said collection device.
Claim 63
Dependent Claim 32 words
The method of claim 57 wherein said stream of pressurized fluid is of at least about 15 psig passing through said wet web structure from said air plenum to said collection device.
Claim 64
Dependent Claim 28 words
The method of claim 57 wherein at least about 70 percent of said stream of pressurized fluid is passed through said wet web structure to said collection device.
Claim 65
Independent Claim 235 words
A method for making a cellulosic web comprising the steps of: a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; b) covering said wet web with a support fabric to form a wet web structure; c) transporting said wet web structure through an air press, said air press including an air plenum and a collection device which are operatively associated with each other and adapted to create a pressure differential across said wet web structure, said air plenum and said collection device cooperating with said wet web structure to form an integral seal therewith; d) passing a stream of pressurized fluid of at greater than 10 psig through said wet web structure from said air plenum to said collection device and creating a vacuum in said collection device of at least about 10 inches of mercury to cause a pressure differential across said wet web structure of at least about 25 inches of mercury, said stream of fluid having a volume of at least 10 standard cubic feet per minute per square inch, said pressure differential noncompressively dewatering said wet web to a consistency of at least about 25 percent; e) transferring said dewatered web to a third fabric; and f) pressing said dewatered web against at least a portion of a heated drying cylinder using said third fabric to a obtain a desired final dryness.
Claim 66
Independent Claim 235 words
A method for making a cellulosic web comprising the steps of: a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; b) covering said wet web with a support fabric to form a wet web structure; c) transporting said wet web structure through an air press, said air press including an air plenum and a collection device which are operatively associated with each other and adapted to create a pressure differential across said wet web structure, said air plenum and said collection device cooperating with said wet web structure to form an integral seal therewith; d) passing a stream of pressurized fluid of at greater than 10 psig through said wet web structure from said air plenum to said collection device and creating a vacuum in said collection device of at least about 10 inches of mercury to cause a pressure differential across said wet web structure of at least about 25 inches of mercury, said stream of fluid having a volume of at least 10 standard cubic feet per minute per square inch, said pressure differential noncompressively dewatering said wet web to a consistency of at least about 25 percent; e) transferring said dewatered web to a third fabric; and f) pressing said dewatered web against at least a portion of a heated drying cylinder using said third fabric to a obtain a desired final dryness.
Claim 67
Dependent Claim 32 words
The method of claim 61 wherein said stream of pressurized fluid is of at least about 15 psig passing through said wet web structure from said air plenum to said collection device.
Claim 68
Dependent Claim 27 words
The method of claim 61 wherein at least about 70 percent of said stream of fluid is passed through said wet web structure to said collection device.

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Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2003-07-04 2004-01-03 2004-07-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2007-07-04 2008-01-03 2008-07-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2011-07-04 2012-01-03 2012-07-04 $7700.00 Window Closed / Lapsed

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