EP1916333B1

EP1916333B1 - Fabric comprising nonwoven elements for use in the manufacture of tissue products having visually discernable background texture regions bordered by curvilinear decorative elements and method of manufacture of tissue products

Info

Publication number: EP1916333B1
Application number: EP08001568.8A
Authority: EP
Inventors: Mark Alan Burazin; Jeffrey D. Lindsay
Original assignee: Kimberly Clark Worldwide Inc; Kimberly Clark Corp
Current assignee: Kimberly Clark Worldwide Inc; Kimberly Clark Corp
Priority date: 2001-11-02
Filing date: 2002-10-17
Publication date: 2016-06-01
Anticipated expiration: 2022-10-17
Also published as: BR0213370A; EP1442173B1; EP1442173A1; WO2003040470A1; BR0213370B1; DE60225580D1; TW200300192A; CA2463892A1; MXPA04003428A; CA2463892C; EP1916333A1; DE60225580T2

Description

BACKGROUND

The present invention relates to the field of paper manufacturing. More particularly, the present invention relates to the manufacture of absorbent tissue products such as bath tissue, facial tissue, napkins, towels, wipers, and the like. Specifically, the present invention relates to Improved fabrics used to manufacture absorbent tissue products having visually discernible background texture regions bordered by curvilinear decorative elements, methods of tissue manufacture, methods of fabric manufacture, and the actual tissue products produced. WO 00/39393 , WO 00/39394 , and WO 98/01618 disclose prior art papermaking processes. US 6,171,447 B1 discloses a papermaking belt having the features of the preamble of claim 1.
In the manufacture of tissue products, particularly absorbent tissue products, there is a continuing need to improve the physical properties and final product appearance. It is generally known in the manufacture of tissue products that there is an opportunity to mold a partially dewatered cellulosic web on a papermaking fabric specifically designed to enhance the finished paper product's physical properties. Such moulding can be applied by fabrics in an uncreped through air dried process as disclosed in U.S. Patent No. 5,672,248 issued on September 30, 1997 to Wendt et al. , or in a wet pressed tissue manufacturing process as disclosed U.S. Patent No. 4,637,859 issued on January 20, 1987 to Trokhan . Wet molding typically imparts desirable physical properties independent of whether the tissue web is subsequently creped, or an uncreped tissue product is produced.
However, absorbent tissue products are frequently embossed in a subsequent operation after their manufacture on the paper machine, while the dried tissue web has a low moisture content, to impart consumer preferred visually appealing textures or decorative lines. Thus, absorbent tissue products having both desirable physical properties and pleasing visual appearances often require two manufacturing steps on two separate machines. Hence, there is a need to combine the generation of visually discernable background texture regions bordered by curvilinear decorative elements with the paper manufacturing process to reduce manufacturing costs. There is also a need to develop a paper manufacturing process that not only imparts visually discernable background texture regions bordered by curvilinear decorative elements to the sheet, but also maximizes desirable physical properties of the absorbent tissue products without deleteriously affecting other desirable physical properties.
Previous attempts to combine the above needs, such as those disclosed in U.S. Patent No. 4,967,805 issued on November 6,1990 to Chiu , U.S. Patent No. 5,328,565 issued on July 12, 1994 to Rasch et al. , and in U.S. Patent No. 5,820,730 issued on October 13, 1998 to Phan et al. , have manipulated the papermaking fabric's drainage in different localized regions to produce a pattern in the wet tissue web in the forming section of the paper machine. Thus, the texture results from more fiber accumulation in areas of the fabric having high drainage and fewer fibers in areas of the fabric having low drainage. Such a method can produce a dried tissue web having a non-uniform basis weight in the localized areas or regions arranged in a systematic manner to form the texture. While such a method can produce textures, the sacrifice in the uniformity of the dried tissue web's physical properties such as tear, burst, absorbency, and density can degrade the dried tissue web's performance while in use.
For the foregoing reasons, there is a need to generate aesthetically pleasing combinations of background texture regions and curvilinear decorative elements in the dried or partially dried tissue web, while being manufactured on the paper machine, using a method that produces a substantially uniform density dried tissue web which has improved performance while in use.
Numerous woven fabric designs are known in papermaking. Examples are provided by Sabut Adanur in Paper Machine Clothing, Lancaster, Pennsylvania: Technomic Publishing, 1997, pp. 33 -113, 139 - 148, 159 - 168, and 211 - 229. Another example is provided in Patent Application WO 00/63489 , entitled "Paper Machine Clothing and Tissue Paper Produced with Same," by H.J. Lamb, published on October 26, 2000.

SUMMARY

The present invention comprises paper manufacturing processes that may satisfy one or more of the foregoing needs. For example, a paper manufacturing fabric of the present invention, when used as a throughdrying, fabric in an uncreped tissue making process, produces an absorbent tissue product having a substantially uniform density as well as possessing visually discernable background texture regions bordered by curvilinear decorative elements. The present invention is also directed towards fabrics for manufacturing the absorbent tissue product, processes of making the absorbent tissue product, processes of making the fabric, and the absorbent tissue products themselves.
Therefore In one aspect, the present invention relates to a sculpted fabric for the manufacture of a tissue web, as set forth in claim 1.
In another aspect, the present invention relates to a method for manufacturing a tissue product as set forth in claim 19.
The background texture regions are designed to impart preferred finished product properties when used as an UCTAD throughdrying fabric, including roll bulk, stack bulk, CD stretch, drape, and durability. The curvilinear decorative elements may provide additional hinge points to enhance finished product drape. The background texture regions in the finished product contrast visually with the curvilinear transition regions, providing the decorative effect.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present invention will be better understood with regard to the hollowing description, appended claims, and accompanying drawings where:

FIGURE 1 is a schematic diagram of a process for making an uncreped dried tissue web in accordance with an embodiment of the present invention.
FIGURE 2 is a schematic diagram of one embodiment of the fabric of the present invention.
FIGURE 3 is a schematic diagram of one embodiment of a sculpted fabric.
FIGURE 4 is a schematic diagram of one embodiment of a sculpted fabric.
FIGURE 5 is a schematic diagram of one embodiment of a sculpted fabric.

The embodiments according to FIGURES 3-5 do not fall within the scope of the claims

DEFINITIONS

As used herein, "curvilinear decorative element" refers to any line or visible pattern that contains either straight sections, curved sections, or both that are substantially connected visually. Thus, a decorative pattern of interlocking circles may be formed from many curvilinear decorative elements shaped into circles. Similarly, a pattern of squares may be formed from many curvilinear decorative elements shaped into individual squares. It is understood that curvilinear decorative elements also may appear as undulating lines, substantially connected visually, forming signatures or patterns.
Also, as used herein "decorative pattern" refers to any non-random repeating design, figure, or motif. It is not necessary that the curvilinear decorative elements form recognizable shapes, and a repeating design of the curvilinear decorative elements is considered to constitute a decorative pattern.
As used herein, "machine-direction" or "MD" refers to the direction of travel of the fabric, the fabric's individual strands, or the paper web while moving through the paper machine. Thus, the MD test data for the tissue refers to the tissue's physical properties in a sample cut lengthwise in the machine-direction. Similarly, "cross-machine direction" or "CD" refers to a direction orthogonal to the machine-direction extending across the width of the paper machine. Thus, the CD test data for the tissue refers to the tissue's physical properties in a sample cut lengthwise in the cross-machine direction. In addition, the strands may be arranged at acute angles to the MD and CD directions. One such arrangement is described in "Rolls of Tissue Sheets Having Improved Properties", Burazin et al., EP 1 109 969 A1 which published on June 27, 2001 and incorporated herein by reference to the extent it is not contradictory herewith.
As used herein, "plane difference" refers to the z-direction height difference between an elevated region and the highest immediately adjacent depressed region. Z-direction refers to the axis mutually orthogonal to the machine direction and cross-machine direction.
As used herein, "transfer fabric" is a fabric that is positioned between the forming section and the drying section of the web manufacturing process.
As used herein, a "filled" transition region is defined as a transition region where the space between the floats in the transition region is partially or completely filled with material, raising the height in the transition area. The filling material may be porous. The filling material may be any of the materials discussed hereinafter for use in the construction of fabrics. The filling material may be substantially deformable, as measured by High Pressure Compressive Compliance (defined hereinafter).
As used herein, "Frazier air permeability" refers to the measured value of a well-known test with the Frazier Air Permeability Tester In which the permeability of a fabric Is measured as standard cubic feet of airflow per square foot of material per minute with an air pressure differential of 0,5 inches (12.7 mm) of water under standard conditions. The fabrics of the present invention can have any suitable Frazier air permeability. For example, thoughdrying fabrics can have a permeability from about 55 standard cubic feet per square foot per minute (about 16 standard cubic meters per square meter per minute) or higher, more specifically from about 100 standard cubic feet per square foot per minute (about 30 standard cubic meters per square meter per minute) to about 1,700 standard cubic feet per square foot per minute (about 520 standard cubic meters per square meter per minute), and most specifically from about 200 standard cubic feet per square foot per minute (about 60 standard cubic meters per square meter per minute) to about 1,500 standard cubic feet per square foot per minute (about 460 standard cubic meters per square meter per minute).

DETAINED DESCRIPTION

The Process

Referring to FIGURE 1 , a process of carrying out the present invention will be described in greater detail, The process shown depicts an uncreped through dried process, but it will be recognized that any known papermaking method or tissue making method can be used in conjunction with the fabrics of the present invention. Related uncreped through air dried tissue processes are described in U.S. Patent No. 5,656,132 issued on August 12, 1997 to Farrington et al . and in U.S. Patent No. 6,017,417 issued on January 25, 2000 to Wendt et al. In addition, fabrics having a sculpture layer and a load bearing layer useful for making uncreped through air dried tissue products are disclosed in U.S. Patent No. 5,429,686 issued on July 4, 1995 to Chiu et al. Exemplary methods for the production of creped tissue and other paper products are disclosed in U.S. Patent No. 5,855,739, issued on January 5, 1999 to Ampulski et al. ; U.S. Patent No. 5,897,745, issued on April 27, 1999 to Ampulski et al. ; U.S. Patent No. 5,893,965, issued on April 13, 1999 to Trokhan et al. ; U.S. Patent No. 5,972,813 issued on October 26, 1999 to Polat et al. ; U.S. Patent No. 5,503,71.5, issued on April 2, 1996 to Trokhan et al. ; U.S. Patent No. 5,935,381, issued on August 10, 1999 to Trokhan et al. ; U.S. Patent No. 4,529,480, issued on July 16, 1985 to Trokhan ; U.S. Patent No. 4,514,345. issued on April 30, 1985 to Johnsori et al. ; U.S. Patent No. 4,528,239, issued on July 9, 1985 to Trokhan : U.S. Patent No. 5,098,522, issued on March 24,1992 to Smurkoski et al. ; U.S. Patent No. 5,260,171, issued on November 9, 1993 to Smurkoski et al. ; U.S. Patent No. 5,275,700, issued on January 4, 1994 to Trokhan ; U.S. Patent No. 5,328,565, issued on July 12, 1994 to Rasch et al. ; U.S. Patent No. 5,334,289, issued on August 2, 1994 to Trokhan at al.; U.S. Patent No. 5,431,786, issued on July 11, 1995 to Rasch et al. ; U.S. Patent No. 5,496,624, Issued on March 5, 1996 to Stelljes, Jr. et al. ; U.S. Patent No. 5,500,277, issued on March 19, 1996 to Trokhan et al. ; U.S. Patent No. 5,514,523, issued on May 7, 1996 to Trokhan et al. ; U.S. Patent No. 5,554,467, issued on September 10, 1996, to Trokhan et al. ; U.S. Patent No. 5,566,724 , issued on October 22,1996 to Trokhan et al.; U.S. Patent No. 5,624,790, Issued on April 29, 1997 to Trokhan et al. ; U.S. Patent No. 6,010,598, issued on January 4,2000 to Boutilier et al. ; and, U.S. Patent No. 5,628,876. issued on May 13, 1997 to Ayers et al. ,
In Figure 1 , a twin wire former 8 having a papermaking headbox 10 injects or deposits a stream 11 of an aqueous suspension of papermaking fibers onto a plurality of forming fabrics, such as the outer forming fabric 12 and the inner forming fabric 13, thereby forming a wet tissue web 15. The forming process of the present invention may be any conventional forming process known in the papermaking industry. Such formation processes include, but are not limited to, Fourdriniers, roof formers such as suction breast roll formers, and gap formers such as twin wire formers and crescent formers.
The wet tissue web 15 forms on the inner forming fabric 13 as the inner forming fabric 13 revolves about a forming roll 14. The inner forming fabric 13 serves to support and carry the newly-formed wet tissue web 15 downstream in the process as the wet tissue web 15 is partially dewatered to a consistency of about 10 percent based on the dry weight of the fibers. Additional dewatering of the wet tissue web 15 may be carried out by known paper making techniques, such as vacuum suction boxes, while the inner forming fabric 13 supports the wet tissue web 15. The wet tissue web 15 may be additionally dewatered to a consistency of at least about 20%, more specifically between about 20% to about 40%, and more specifically about 20% to about 30%. The wet tissue web 15 is then transferred from the inner forming fabric 13 to a transfer fabric 17 traveling preferably at a slower speed than the inner forming fabric 13 in order to impart Increased MD stretch into the wet tissue web 15.
The wet tissue web 15 is then transferred from the transfer fabric 17 to a throughdrying fabric 19 whereby the wet tissue web 15 preferentially is macroscopically rearranged to conform to the surface of the throughdrying fabric 19 with the aid of a vacuum transfer roll 20 or a vacuum transfer shoe like the vacuum shoe 18. If desired, the throughdrying fabric 19 can be run at a speed slower than the speed of the transfer fabric 17 to further enhance MD stretch of the resulting absorbent tissue product 27. The transfer is preferably carried out with vacuum assistance to ensure conformation of the wet tissue web 15 to the topography of the throughdrying fabric 19. This yields a dried tissue web 23 having the desired bulk, flexibility, CD stretch, and enhances the visual contrast between the background texture regions 38 and 50 and the curvilinear decorative elements which border the background texture regions, 38 and 50.
In one embodiment, the throughdrying fabric 19 imparts the curvilinear decorative elements and background texture regions 38 and 50, such as substantially broken-line like corduroy, to the wet tissue web 15. It is possible, however, to use a transfer fabric 17 in accordance with the present invention to achieve similar results. Furthermore, it is also possible to eliminate the transfer fabric 17, and transfer the wet tissue web 15 directly to the throughdrying fabric 19 of the present invention. Both alternative papermaking processes are within the scope of the present invention, and will produce a decorative absorbent tissue product 27.
While supported by the throughdrying fabric 19, the wet tissue web 15 is dried to a final consistency of about 94 percent or greater by a throughdryer 21 and is thereafter transferred to a carrier fabric 22. Alternatively, the drying process can be any noncompressive drying method that tends to preserve the bulk of the wet tissue web 15.
In another aspect of the present invention, the wet tissue web 15 Is pressed against a Yankee dryer by a pressure roll while supported by a sculpted fabric 100 comprising visually discernable background texture regions 38 and 50 bordered by curvilinear decorative elements. Such a process, without the use of the sculpted fabrics 100 of the present invention, is shown in U.S. Patent No. 5,820,730 issued on October 13,1998 to Phan et al. The compacting action of a pressure roll will tend to density a resulting absorbent tissue product 27 in the localized regions corresponding to the highest portions of the sculpted fabric 100.
The dried tissue web 23 is transported to a reel 24 using a carrier fabric 22 and an optional carrier fabric 25. An optional pressurized turning roll 26 can be used to facilitate transfer of the dried tissue web 23 from the carrier fabric 22 to the carrier fabric 25. If desired, the dried tissue web 23 may additionally be embossed to produce a combination of embossments and the background texture regions and curvilinear decorative elements on the absorbent tissue product 27 produced using the throughdrying fabric 19 and a subsequent embossing stage.
Once the wet tissue web 15 has been non-compressively dried, thereby forming the dried tissue web 23, it is possible to crepe the dried tissue web 23 by transferring the dried tissue web 23 to a Yankee dryer prior to reeling, or using alternative foreshortening methods such as microcreping as disclosed in U.S. Patent No. 4,919,877 issued on April, 24,1990 to Parsons at al.
In an alternative embodiment not shown, the wet tissue web 15 may be transferred directly from the inner forming fabric 13 to the throughdrying fabric 19 and the transfer fabric 17 eliminated. The throughdrying fabric 19 may be traveling at a speed less than the inner forming fabric 13 such that the wet tissue web 15 is rush transferred, or, in the alternative, the throughdrying fabric 19 may be traveling at substantially the same speed as the inner forming fabric 13. If the throughdrying fabric 19 is traveling at a slower speed than the speed of the inner forming fabric 13, an uncreped absorbent tissue product 27 Is produced. Additional foreshortening after the drying stage may be employed to improve the MD stretch of the absorbent tissue product 27. Methods of foreshortening the absorbent tissue product 27 include, by way of illustration and without limitation, conventional Yankee dryer creping, microcreping, or any other method known in the art.
Differential velocity transfer from one fabric to another can follow the principles taught in any one of the following patents: U.S. Patent No. 6,667,636, issued on September 16, 1997 to Engel et al. ; U.S. Patent No. 5,830,321, issued on November 3, 1998 to Lindsay et al. ; U.S. Patent No. 4,440,597, issued on April 3, 1984 to Wells et al. , U.S. Patent No. 4,551,199, issued on November 5, 1985 to Weldon ; and, U.S. Patent No. 4,849,054, issued on July 18, 1989 to Klowak .
In yet another alternative embodiment of the present invention, the inner forming fabric 13, the transfer fabric 17, and the throughdrying fabric 19 can all be traveling at substantially the same speed. Foreshortening may be employed to improve MD stretch of the absorbent tissue product 27. Such methods include, by way of illustration without limitation, conventional Yankee dryer creping or microcreping.
Any known papermaking or tissue manufacturing method may be used to create a three-dimensional web 23 using the fabrics 100 of the present invention as a substrate for imparting texture to the wet tissue web 15 or the dried tissue web 16. Though the fabrics 100 of the present invention are especially useful as through drying fabrics and can be used with any known tissue making process that employs throughdrying, the fabrics 100 of the present invention can also be used in the formation of paper webs as forming fabrics, transfer fabrics, carrier fabrics, drying fabrics, imprinting fabrics, and the like in any known papermaking or tissue making process. Such methods can include variations comprising any one or more of the following steps in any feasible combination:

web formation in a wet end In the form of a classical Fourdrinier, a gap former, a twin-wire former, a crescent former, or any other known former comprising any known headbox, including a stratified headbox for bringing layers of two or more furnishes together into a single web, or a plurality of headboxes for forming a multilayered web, using known wires and fabrics or fabrics of the present invention;
web formation or web dewatering by foam-based processes, such as processes wherein the fibers are entrained or suspended in a foam prior to dewatering, or wherein foam is applied to an embryonic web prior to dewatering or drying, including the methods disclosed in U.S. Patent 5,178,729, issued on January 12, 1993 to Janda , and U.S. Patent No. 6,103,060, issued on August 15, 2000 to Munerelle et al. ;
differential basis weight formation by draining a slurry through a forming fabric having high and low permeability regions, including fabrics of the present invention or any known forming fabric;
rush transfer of a wet web from a first fabric to a second fabric moving at a slower velocity than the first fabric, wherein the first fabric can be a forming fabric, a transfer fabric, or a throughdrying fabric, and wherein the second fabric can be a transfer fabric, a throughdrying fabric, a second throughdrying fabric, or a carrier fabric disposed after a throughdrying fabric (one exemplary rush transfer process is disclosed in U.S. Patent No. 4,440,597 to Wells et al ), wherein the aforementioned fabrics can be selected from any known suitable fabric including fabrics of the present invention;
application of differential air pressure across the web to mold it into one or more of the fabrics on which the web rests, such as using a high vacuum pressure in a vacuum transfer roll or transfer shoe to mold a wet web into a throughdrying fabric as it is transferred from a forming fabric or intermediate carrier fabric, wherein the carrier fabric, throughdrying fabric, or other fabrics can be selected from the fabrics of the present invention or other known fabrics;
use of an air press or other gaseous dewatering methods to increase the dryness of a web and/or to impart molding to the web, as disclosed In U.S. Patent No. 6096169, issued on August 1, 2000 to Hermans et al. : U.S. Patent No. 6,197,154, issued on March 6, 2001 to Chen et al. ; and, U.S. Patent No. 6,143,135, issued on November 7, 2000 to Hada et. al.:
drying the web by any compressive or noncompressive drying process, such as throughdrying, drum drying, infrared drying, microwave, drying, wet pressing, impulse drying (e.g., the methods disclosed in U.S. Patent No. 5,353,521, issued on October 11, 1994 to Orloff and U.S. Patent No. 5,598,642, issued on February 4, 1997 to Orloff et al. ), high Intensity nip dewatering, displacement dewatering (see J.D. Lindsay, "Displacement Dewatering To Maintain Bulk," Raperi Ja Puu, vol. 74, No. 3, 1992, pp. 232-242), capillary dewatering (see any of U.S. Patent Nos. 5,598,643 ; 5,701,682 ; and 5,699,626 , all of which issued to Chuang et al.), steam drying, etc.
printing, coating, spraying, or otherwise transferring a chemical agent or compound on one or more sides of the web uniformly or heterogeneously, as in a pattern, wherein any known agent or compound useful for a web-based product can be used (e.g., a softness agent such as a quaternary ammonium compound, a silicone agent, an emollient, a skin-wellness agent such as aloe vera extract, an antimicrobial agent such as citric acid, an odor-control agent, a pH control agent, a sizing agent; a polysaccharide derivative, a wet strength agent, a dye, a fragrance, and the like), including the methods of U.S. Patent No. 5,871,763, issued on February 16, 1999 to Luu et al. ; U.S. Patent No. 5,716,692, issued on February 10, 1998 to Warner et al. ; U.S. Patent No. 5,573,637, issued on November 12, 1996 to Ampulski et al. ; U.S. Patent No. 5,607,980, issued on March 4,1997 to McAtee et al. ; U.S. Patent No. 5,614,293, issued on March 25, 1997 to Krzysik et al. ; U.S. Patent No. 5,643,588, issued on July 1, 1997 to Roe et al. ; U.S. Patent No. 6,650,218, issued on July 22,1997 to Krzysik et al. ; U.S. Patent No. 5,990,377, issued on November 23, 1999 to Chen et al. ; and, U.S. Patent No. 5,227,242, issued on July 13, 1993 to Walter et al. ;
imprinting the web on a Yankee dryer or other solid surface, wherein the web resides on a fabric that can have deflection conduits (openings) and elevated regions (including the fabrics of the present invention), and the fabric is pressed against a surface such as the surface of a Yankee dryer to transfer the web from the fabric to the surface, thereby imparting densification to portions of the web that were in contact with the elevated regions of the fabric, whereafter the selectively densified web can be creped from or otherwise removed from the surface;
creping the web from a drum dryer, optionally after application of a strength agent such as latex to one or more sides of the web, as exemplified by the methods disclosed in U.S. Patent No. 3,879,257, Issued on April 22, 1975 to Gentile et al. ; U.S. Patent No. 5,886,418, issued on March 23, 1999 to Anderson et al. ; U.S. Patent No. 6,149,768, issued on November 21, 2000 to Hepford ;
creping with serrated crepe blades (e.g., see U.S. Patent No. 5,885,416, issued on March 23, 1999 to Marinack et al. ) or any other known creping or foreshortening method; and,
converting the web with known operations such as calendering, embossing, slitting, printing, forming a multiply structure having two, three, four, or more plies, putting on a roll or in a box or adapting for other dispensing means, packaging in any known form, and the like.

The fabrics 100 of the present invention can also be used to impart texture to airlaid webs, either serving as a substrate for forming a web, for embossing or imprinting an airlaid web, or for thermal molding of a web.

Fabric Structure

FIGURE 2 shows a schematic of a composite sculpted fabric 100 comprising a base 102 with nonwoven raised elements 108 attached thereon. Together, the base 102 and the raised elements 108 form an upper porous member 105 in the composite sculpted fabric 100 which can comprise additional layers (not shown) beneath the base 102. As discussed hereafter, the sculpted fabric 100 need not be composite, but can be formed from a single material, though composite materials such as nonwoven elements joined to a woven fabric can be useful in providing strength or other properties in some embodiments. When used as a throughdrying fabric, the sculpted fabric 100 (like other fabrics of the present invention intended for use in throughdrying) generally should be permeable enough to permit through drying under a gas pressure differential. For example, the porous upper member 105 or the entire sculpted fabric 100 can have a Frazier air permeability of about 250 standard cubic feet per square foot per minute (about 76 standard cubic meters per square meter per minute) or higher. When used as an imprinting fabric or other non-throughdrying fabric, the sculpted fabric 100 can, in some embodiments, have a lower permeability, such as a Frazier air permeability of about 150 standard cubic feet per square foot per minute (about 46 standard cubic meters per square meter per minute) or less.
The raised elements 108 as shown are aligned substantially in the machine direction 120 (orthogonal to the cross-machine direction 118) in the portion of the composite sculpted fabric 100 shown, though the raised elements 108 could be oriented in any direction. All embodiments shown herein for raised elements 108 oriented primarily in the machine direction can be adapted equally well to raised elements 108 oriented in the cross-machine direction, for example. The raised elements 108 as depicted have a height H (relative to the base 102), a length L, and a width W. The height H can be greater than about 0.1 mm, such as from about 0.2 mm to about 5 mm, more specifically from about 0.3 mm to about 1.5 mm, and most specifically from about 0.3 mm to about 0.7 mm. The length L can be greater than 2 mm, such as about 3 mm or greater, or from about 4 mm to about 25 mm. The width W can be greater than about 0.1 mm such as from about 0.2 mm to about 2 mm, more specifically from about 0.3 mm to about 1 mm.
In a first background region 38, the machine-direction oriented, elongated raised elements 108 act as floats 60 that serve as first elevated regions 40, with first depressed regions 42 therebetween that reside substantially on the underlying base 102, which can be a woven fabric. In a second background region 50, the raised elements 108 act as floats 60 that serve as second elevated regions 52, with second depressed regions 54 therebetween that reside substantially on the underlying base 102.
A transition region 62 is formed when a first elevated region 40 from a first background region 38 of the composite sculpted fabric 100 has an end 122 in the vicinity of the beginning 124 of two adjacent second elevated regions 52 in a seconde background region 50 of the composite sculpted fabric 100, with the end 122 disposed in the cross-machine direction 118 at a position intermediate to the respective cross-machine direction locations of the two adjacent second elevated regions 52, wherein the end 122 of raised elements 108 (either a first elevated region 40 or second elevated region 52) refers to the termination of the raised element 108 encountered while moving along the composite sculpted fabric 100 in the machine direction 120, and the beginning 124 of a raised element 108 refers to the initial portion of the raised element 108 encountered while moving along the composite sculpted fabric 100 in the same direction. Were the raised elements 108 oriented in another direction, the direction of orientation for each raised element 108 is the direction one moves along in identifying ends 122 and beginnings 124 of raised elements 108 in order to identify their relationship in a consistent manner. Generally, features of the raised elements 108 can be successfully identified when either of the two possible directions (forward and reverse, for example) among the raised element 108 is defined as the positive direction for travel.
The transition region 62 separates the first and second background regions 38 and 50, The shifting of the cross-machine directional locations of the raised elements 108 in the transition region 62 creates a break in the patterns of the first and second background regions 38 and 50, contributing to the visual distinctiveness of the portion of the wet tissue web 15 molded against the transition region 62 of the composite sculpted fabric 100 relative to the portion of the wet tissue web 15 molded against the surrounding first and second background regions 38 and 50. In the embodiment shown in FIGURE 2 , the transition region 62 is also characterized by a gap width G which is the distance in the machine direction 120 (or, more generally, whatever direction the raised elements 108 are predominantly oriented in) between an end 122 of a raised element 108 in the first background region 38 and the nearest beginning 124 of a raised element 108 in the second background region 50. The gap width G can vary in the transition region 62 or can be substantially constant. For positive gap widths G such as is shown in FIGURE 2 , G can vary, by way of example, from about 0 to about 20 mm, such as from about 0.5 mm to about 8 mm, or from about 1 mm to about 3 mm.
A base 102 can be a woven or nonwoven fabric, or a composite of woven and nonwoven elements or layers. The base 102 generally serves to hold the raised elements 108 in place, and can provide strength and integrity to the entire composite sculpted fabric 100, which can comprise additional layers (not shown) such as load-bearing layers beneath the base 102. The base 102 can also be made from the same material as the raised elements 108, and may be unitary with the raised elements 108, providing a unitary upper porous member 105, in contrast to the integral composite upper porous member 105 shown in Figure 18, where raised elements 108 have been attached to a separate base 102 rather than being formed therewith or therefrom.
In the case of a unitary upper porous member 105, the upper porous member 105 can be entirely nonwoven, as can be the entire sculpted fabric 100. For example, the upper porous member 105 can be formed from a single, unitary porous web such as a fibrous nonwoven layer of a polymeric material formed by any known process, including materials such as an airlaid web, a spunbond fabric, a meltblown fabric, a bonded carded web, an electrospun fabric, or combinations thereof. The porous web can be sculpted according to the principles of the present invention to Impart raised elements 108 above a base 102. Methods of sculpting can include, embossing to densffy selected regions to form a base 108 serving as a depressed layer unitary with raised elements 108. A variety of operations can transform an initially substantially uniform porous web Into a sculpted upper porous member 105 (or sculpted fabric 100) according to the present invention. Such operations can leave the porous web with substantially the same basis weight distribution (i.e., no mass is added or subtracted from the porous web during treatment), as is commonly the case for embossing, stamping, thermal molding, and the like, or the operation can modify the basis weight of the porous web. Operations that modify the basis weight of the porous web include mechanical drilling, laser drilling, adding molten resin that is subsequently cured to from raised elements 108 (the resin can be substantially the same material as the base 102 and if properly bonded, can become substantially unitary with the base 102), and the like. A porous web can be molded by any means (cast molding, thermal molding, etc.) initially or after initial formation into a unitary sculpted upper porous member 105.
The embodiment of the base 102 depicted in Figure 2 is a woven base fabric, with the shutes 45 extending in the cross-machine direction 118 and the warps 44 in the machine direction 120, The base 102 can be woven according to any pattern known in the art and can comprise any materials known in the art. As with any woven strands for any fabrics of the present invention, the strands need not be circular in cross-section but can be elliptical, flattened, rectangular, cabled, oval, semi-oval, rectangular with rounded edges, trapezoidal, parallelograms, bilobal, multi-lobal, or can have capillary channels. The cross sectional shapes may vary along a raised element 108; multiple raised elements with differing cross sectional shapes may be used on the composite sculpted fabric 100 as desired. Hollow filaments can also be used.
The raised elements 108 can be Integral with the base 102. For example, a composite sculpted fabric 100 can be formed by photocuring of elevated resinous elements which encompass portions of the warps 44 and shutes 45 of the base 102. Photocuring methods can include UV curing, visible light curing, electron beam curing, gamma radiation curing, radiofrequency curing, microwave curing, infrared curing, or other known curing methods involving application of radiation to cure a resin. Curing can also occur via chemical reaction without the need for added radiation as in the curing of an epoxy resin, extrusion of an autocuring polymer such as polyurethane mixture, thermal curing, solidifying of an applied hotmelt or molten thermoplastic, sintering of a powder in place on a fabric, and application of material to the base 102 in a pattern by known rapid prototyping methods or methods of sculpting a fabric. Photocured resin and other polymeric forms of the raised elements 108 can be attached to a base 102 according to the methods in any of the following patents: U.S. Patent No. 5,679,222, issued on October 21, 1997 to Rasch et al. ; U.S. Patent No. 4,514,345, issued on April 30, 1985 to Johnson et al. ; U.S. Patent No. 5,334,289, issued on August 2, 1994 to Trokhan et al. ; U.S. Patent No. 4,528,239, issued on July 9, 1985 to Trokhan ; U.S. Patent No. 4,637,859, issued on January 20,1987 to Trokhan ; commonly owned U.S. Patent No. 6,120,642, issued on September 19, 2000 to Lindsay and Burazin ; and, commonly owned patent applications Serial Nos. 09/705,684 and 09/706,149 , both filed on November 3, 2000 by Lindsay et al.. The raised elements 108 can also be extruded or applied as a foam material to be joined to the base 102. Sintering, adhesive bonding, thermal fusing, or other known methods can be used to attach the raised elements 108 to the base 102, especially in the formation of a composite sculpted fabric 30 having nonwoven elements on the tissue contacting side.
U.S. Patent No. 6,120,642, issued on September 19, 2000 to Lindsay and Burazin , discloses methods of producing sculpted nonwoven throughdrying fabrics, and such methods can be applied in general to create composite sculpted fabrics 100 of the present invention. In one embodiment, such composite sculpted fabrics 100 comprise an upper porous nonwoven member and an underlying porous member supporting the upper porous member, wherein the upper porous nonwoven member comprises a nonwoven material (e.g., a fibrous nonwoven, an extruded polymeric network, or a foam-based material) that is substantially deformable. More specifically, the can have a High Pressure Compressive Compliance (hereinafter defined) greater than 0.05, more specifically greater than 0.1, and wherein the permeability of the wet molding substrate is sufficient to permit an air pressure differential across the wet molding substrate to effectively mold said web onto said upper porous nonwoven member to impart a three-dimensional structure to said web.
As used herein, "High Pressure Compressive Compliance" is a measure of the deformability of a substantially planar sample of the material having a basis weight above 50 g/m² (gsm) compressed by a weighted platen of 7.6cm (3-inches) in diameter to impart mechanical loads of 1.4kPa (0.2 psi) and then 14kPa (2.0 psi), measuring the thickness of the sample while under such compressive loads. Subtracting the ratio of thickness at 14kPa (2,0 psi) to thickness at 1.4kPa (0.2 psi) from 1 yields the High Pressure Compressive Compliance. In other word, High Pressure Compressive Compliance = 1 - (thickness at 14kPa (2.0 psi) thickness at 1.4kPa (0.2 psi). The High Pressure Compressive Compliance can be greater than about 0.05, specifically greater than about 0.15, more specifically greater than about 0.25, still more specifically greater than about 0.35, and most specifically between about 0.1 and about 0.5. In another embodiment, the High Pressure Compressive Compliance can be less than about 0.05, in cases where a less deformable composite sculpted fabric 100 is desired.
Other known methods can be used to created the composite sculpted fabrics 100 of the present invention, including laser drilling of a polymeric web to impart elevated and depressed regions, ablation, extrusion molding or other molding operations to impart a three-dimensional structure to a nonwoven material, stamping, and the like, as disclosed in commonly owned patent applications Serial Nos. 09/705,684 an 09/706,149 , both filed on November 3,2000 by Lindsay et al.
It is recognized that other topographical elements may be present on the surface of the composite sculpted fabric 100 as long as the ability of the raised elements 108 and the transition region 62 to create a visually distinctive molded wet tissue web 15 is not compromised. For example, the composite sculpted fabric 100 could further comprise a plurality of minor raised elements (not shown) such as ovals or lines having a height less than, for example, about 50% of the minimum height H₁ of the raised elements 108.
FIGURES 3 - 5 are schematic diagram views of the raised elements 108 in a composite sculpted fabric 100 depicting alternate forms of the raised elements 108. In each case, a set of first raised elements 108' in a first background region 38 interacts with a set of second raised elements 108" in a second background region 128 to define a transition region 62 between the first and second background regions 38 and 50, wherein both the discontinuity or shift in the pattern across the transition region 62 as well as an optional change in surface topography along the transition region 62 contribute to a distinctive visual appearance in the wet tissue web 15 molded against the composite sculpted fabric 100, wherein the loci of transition regions 62 define a visible pattern in the molded wet tissue web 15 (not shown). In FIGURE 3 , the first and second raised elements 108' and 108" overlap slightly and define a nonlinear transition region 62 (i.e., there is a slight curve to it as depicted). Further, parallel, adjacent raised elements 108 in either a first or second background region 38 or 50, are spaced apart in the cross-machine direction 118 by a distance S slightly greater than the width W of a first or second raised element 108' or 108" (e.g., the cross-machine direction spacing from centerline to centerline of the first and second raised elements 108' and 108" divided by the width W of the first and second raised elements 108' and 108" can be greater than about 1, such as from about 1.2 to about 5, or from about 1.3 to about 4, or from about 1.5 to about 3. In FIGURE 4 the spacing S is nearly the same as the width W (e.g., the ratio S/W can be less than about 1.2, such as about 1.1 or less or about 1.05 or less). Further, the overlapping first and second raised elements 108' and 108" in the transition region 62 results in a gap width of about-2W or less (meaning that the ends 122 and beginnings 124 of the first and second raised elements 108' and 108" overlap by a distance of about twice or more the width W of the first and second raised elements 108' and 108"). In FIGURE 5 , the tapered raised elements 108 are depicted which are otherwise similar to the raised elements 108 as shown in FIGURE 3 .
It will be recognized that the shapes and dimensions of the raised elements 108 need not be similar throughout the composite sculpted fabric 100, but can differ from any of the first and second background region 38 or 50 to another or even within a first or second background region 38 or 50. Thus, there may be a first background region 38 comprising cured resin first raised elements 108' having a shape and dimensions (W, L, H, and S, for example) different from those of the second raised elements 108" of the second background region 50.

Claims

A sculpted fabric (100) for the manufacture of a tissue web (15), having a tissue machine contacting side and a tissue contacting side, and comprising on the tissue contacting side an upper porous member (105) comprising a base (102) with nonwoven elevated regions (108) thereon comprising a first group of nonwoven raised elements and a second group of nonwoven raised elements, both raised relative to the base (102), wherein the first group of nonwoven raised elements extends in a first direction and the second group of nonwoven raised elements extends in a second direction, wherein the first direction of the first group of nonwoven raised elements is substantially the same as the second direction of the second group of nonwoven raised elements, and wherein the first and second groups of nonwoven raised elements are arranged on the base (102) to produce elevated and depressed regions (40, 52, 42, 54) defining a three-dimensional tissue contacting surface comprising:
a) a first background region (38) having a set of substantially parallel first elevated regions (40) comprising at least a subset of the first group of nonwoven raised elements, and comprising a first group of depressed regions (42), wherein the first elevated regions (40) and the first depressed regions (42) alternate;

b) a second background region (50) having a set of substantially parallel second elevated regions (52) comprising at least a subset of the second group of nonwoven raised elements, and comprising a second group of depressed regions (54), wherein the second elevated regions (52) and the second depressed regions (54) alternate; and,

c) a transition region (62) positioned between the first and second background regions (38, 50), wherein the first elevated regions (40) of the first background region (38) terminate and the second elevated regions (52) of the second background region (50) terminate, and wherein the transition region has greater surface depth than the first or second background regions, wherein the transition region (62) is characterized by a gap width which is zero or positive, the gap width being the distance in said first and second directions between the end (122) of a first elevated region (40) and the nearest beginning (124) of a second elevated region (52).
The sculpted fabric (100) of Claim 1, wherein the upper porous member (105) consists essentially of nonwoven materials.
The sculpted fabric (100) of Claim 2, wherein the sculpted fabric (100) consists essentially of nonwoven materials.
The sculpted fabric (100) of Claim 2, wherein the upper porous member (105) is joined to an underlying strength layer.
The sculpted fabric (100) of Claim 4, wherein the underlying strength layer comprises a woven fabric.
The sculpted fabric (100) of Claim 1, wherein the base (102) of the upper porous member (105) is unitary with at least one of the first group of nonwoven raised elements or the second group of nonwoven raised elements.
The sculpted fabric (100) of Claim 1, wherein the sculpted fabric (100) is substantially unitary.
The sculpted fabric (100) of Claim 1, wherein the sculpted fabric (100) comprises a three-dimensional fibrous nonwoven layer.
The sculpted fabric (100) of Claim 1, wherein the sculpted fabric (100) comprises a nonwoven layer of substantially uniform basis weight.
The sculpted fabric (100) of Claim 1, wherein the upper porous member (105) comprises a fibrous nonwoven web of substantially nonuniform basis weight.
The sculpted fabric (100) of Claim 1, wherein the upper porous member (105) comprises a fibrous nonwoven web.
The sculpted fabric (100) of Claim 11, wherein the base (102) of the upper porous member (105) comprises a fibrous nonwoven web.
The sculpted fabric (100) of Claim 1, wherein the first direction of the first group of nonwoven raised elements is in the cross-machine direction (118).
The sculpted fabric (100) of Claim 1, wherein the first direction of the first group of nonwoven raised elements is at an acute angle to the cross-machine direction (118).
The sculpted fabric (100) of Claim 1, wherein the first direction of the first group of nonwoven raised elements is in the machine direction (120).
The sculpted fabric (100) of Claim 1, wherein the first direction of the first group of nonwoven raised elements is at an acute angle to the machine direction (120).
The sculpted fabric (100) of Claim 1, wherein the base (102) comprises a non-woven material.
The sculpted fabric (100) of Claim 1, wherein the base (102) comprises a woven material.
A method of making a tissue product comprising:
a) depositing an aqueous suspension of papermaking fibers onto a forming fabric thereby forming a wet tissue web (15);

b) transferring the wet tissue web (15) to a sculpted fabric (100) as claimed in any of claims 1 to 18; and

c) drying the wet tissue web (15).
The method of Claim 19, herein the wet tissue web (15) has a consistency of at least about 20 percent when the wet tissue web (15) is transferred to the sculpted fabric (100).
The method of Claim 19, wherein drying the wet tissue web (15) comprises noncompressive drying.
The method of Claim 21, wherein the noncompressive drying the wet tissue web (15) comprises through air drying on a throughdrying fabric thereby forming a dried tissue web.
The method of Claim 22, wherein the speed of the throughdrying fabric is from about 10 to about 80 percent slower than the speed of the forming fabric.
The method of Claim 22, further comprising transferring the wet tissue web (15) from the forming fabric to a transfer fabric before transferring the wet tissue web (15) to the throughdrying fabric wherein the speed of the transfer fabric is from about 10 to about 80 percent slower than the speed of the forming fabric.
The method of Claim 24, wherein the speed of the transfer fabric is substantially the same as the speed of the sculpted fabric (100).
The method of Claim 21, wherein the wet tissue web (15) is at least partially throughdried on the sculpted fabric (100).
The method of Claim 19, wherein the sculpted fabric (100) is a transfer fabric.
The method of Claim 22, wherein the dried tissue web is not creped.
The method of Claim 22, wherein the dried tissue web is transferred to a Yankee dryer.
The method of Claim 29, wherein the dried tissue web is removed from the Yankee dryer without creping.
The method of Claim 29, wherein the dried tissue web is removed from the Yankee dryer with creping.
The method of Claim 22, further comprising dewatering the wet tissue web (15) by at least one of displacement dewatering, capillary dewatering, and application of an air press.
The method of Claim 27, further comprising dewatering the wet tissue web (15) by at least one of impulse drying, radiofrequency drying, long nip pressing, wet pressing, steam drying, high intensity nip drying, and infrared drying.
The method of Claim 19, wherein the wet tissue web (15) is treated with a chemical strength agent and creped two or more times.
The sculpted fabric (100) of claim 1, wherein the transition region (62) has greater surface depth than the first and second background regions (38, 50).