CA2391027A1 - Pin seamed papermaker's press felt with laminated base fabric having low melt material machine direction yarns - Google Patents
Pin seamed papermaker's press felt with laminated base fabric having low melt material machine direction yarns Download PDFInfo
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- CA2391027A1 CA2391027A1 CA002391027A CA2391027A CA2391027A1 CA 2391027 A1 CA2391027 A1 CA 2391027A1 CA 002391027 A CA002391027 A CA 002391027A CA 2391027 A CA2391027 A CA 2391027A CA 2391027 A1 CA2391027 A1 CA 2391027A1
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- fabric
- layer
- machine direction
- direction yarns
- press felt
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- D—TEXTILES; PAPER
- D03—WEAVING
- D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
- D03D3/00—Woven fabrics characterised by their shape
- D03D3/04—Endless fabrics
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F7/00—Other details of machines for making continuous webs of paper
- D21F7/08—Felts
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F7/00—Other details of machines for making continuous webs of paper
- D21F7/08—Felts
- D21F7/083—Multi-layer felts
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F7/00—Other details of machines for making continuous webs of paper
- D21F7/08—Felts
- D21F7/10—Seams thereof
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- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Paper (AREA)
- Woven Fabrics (AREA)
Abstract
A press felt that can have a reduced tendency to fray at the seam cut includes: a paper side batt layer; a machine side batt layer; and a base fabric layer sandwiches between the paper side batt layer and the machine side batt layer.
The base fabric layer comprises a first fabric and a second fabric. The first fabric includes machine direction yarns and cross machine direction yarns interwoven with the machine direction yarns. The first fabric has first and second ends with loops, wherein the loops of the first end are interdigitated with the loops of the second end, and the loops of said first and second ends receive a pin to form the first fabric into an endless belt having a seam. The second fabric is formed into an endless belt overlying the first fabric and includes machine direction yarns and cross machine direction yarns interwoven with the machine direction yarns, wherein the machine direction yarns are formed of a low melt material. In this configuration, the low melt machine direction yarns of the second fabric may have a reduced tendency to fray at the seam cut during prolonged operation.
The base fabric layer comprises a first fabric and a second fabric. The first fabric includes machine direction yarns and cross machine direction yarns interwoven with the machine direction yarns. The first fabric has first and second ends with loops, wherein the loops of the first end are interdigitated with the loops of the second end, and the loops of said first and second ends receive a pin to form the first fabric into an endless belt having a seam. The second fabric is formed into an endless belt overlying the first fabric and includes machine direction yarns and cross machine direction yarns interwoven with the machine direction yarns, wherein the machine direction yarns are formed of a low melt material. In this configuration, the low melt machine direction yarns of the second fabric may have a reduced tendency to fray at the seam cut during prolonged operation.
Description
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' ~ . Ah"..~ey Docket No. 5689-257 PIN SEAMED PAPERMAI~R'S PRESS FELT WITH LAMINATED BASE
FABRIC HAVING LOW MELT MATERIAL MACHINE DIRECTION
YARNS
Field of the Invention The present invention relates generally to papermaking, and more particularly to fabrics used in papermaking.
Background of the Invention In the conventional fourdrinier papermaking process, a water slurry, or suspension, of celluIosic fibers (known as the paper "stock") is fed onto the top of the upper run of an endless belt of woven wire and/or synthetic material that travels between two or more rollers. The belt, often referred to as a "forming fabric," provides, a papermaking surface on the upper surface of its upper run which operates as a filter to separate the cellulosic fibers of the paper stock from the aqueous medium, thereby forming a wet paper web. The aqueous medium drains through mesh openings of the forming fabric, known as drainage holes, by gravity alone or with assistance from one or more suction boxes located on the lower surface i.e. the "machine side") of the upper run of the fabric.
After leaving the forming section, the paper web is transferred to a press section -of the paper machine, in which it is passed thmugh the nips of one or more pairs. of pressure rollers covered with another fabric, typically referred to as a "press felt." Pressure from the rollers removes additional moisture from the web;
, the moisture removal is often enhanced by the presence of a "batt" layer on the press felt. The paper is then conveyed to a drier section for further moisture removal. After drying, the paper is ready for secondary processing and packaging.
Press felts typically include one or more base fabric layers; these can be "flat-woven" and formed after weaving into an endless belt, or can be woven in endless form. Generally, the flat-woven process is preferred, as it is _:-typically less expensive and more versatile than the endless weaving process.
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At~"~ney Docket No. 5689-2S7 Also, in many instances the felt is cut widthwise and reattached to simplify installation on a paper machine, in which case some of the advantages of endless weaving (such as the absence of a seam in the fabric) are lost.
Of course, flat weaving a fabric of a base layer requires that S provision be made for joining it into endless belts. Such joints should be constructed in such a manner that they are sufficiently strong to withstand the extreme load, tanperature, and wear conditions the press felt experiences, yet do not cause the surface of the press felt above the seam to unduly mark the paper.
One popular method of joining the base fabric of a press felt is to form loops with machinedirection yarns on each end of the base fabric. To form the flat-woven base fabric into an endless belt, the ends of the fabric are placed adjacent to each other, with each of the loops on one end positioned between two loops on the other end in interdigitating fashion. A "pin" (usually formed of mutilfilament polymeric fiber strands) is then inserted into all of the loops to join the ends. After the bait 1 S layers) are needled or otherwise attached to the base'layer, the batt layers) are cut at the seam location, the pin is removed, and the finished press felt is shipped to a paper mill. Once at the paper mill, the press felt can be installed by placing it onto a paper machine, then inserting another (usually more.flexible) multifilament pin into the loops. Examples of this type of seam are described in U.S. Patent Nos. 4, 764,417 and 4,737,241 to Gulya, 4,601,785 to Lilja et al., and 5,476,123 to Rydin the disclosures of which are hereby incorporated herein by reference in their entireties.
In some press felts, the base fabric layer itself contains multiple fabric layers i.e., is a "laminated." base layer). For example, a felt may contain a 2S "duplex" fabric i.e., a fabric having upper and lower sets of machine direction yarns interwoven with at least one set, of cross machine direction yarns -also known as a "double layer" fabric) as well as a finer mesh single layer fabric i.e., a fabric having only one set each of machine direction yarns and cross machine -direction yarns). This combination provides a good balance of strength and durability to the felt with relatively little marking. Typically, the felt is constructed by flat weaving the duplex fabric, endless weaving the single layer fabric, joining the duplex fabric with a pin as described above, overlaying the single layer fabric over the duplex fabric, needling both fabric layers with batt to form machine side, ;, ~:~,.~,.I: , ~i I . ~I
At~.,.ney Docket No. 5689-257 and paper side batt layers, removing the pin from the double layer fabric and cutting the batt layers and the single layer fabric at the seam to form a flat . structure. Once at the paper mall, the felt is installed on the papermaking machine by inserting a new, typically thinner and more flexible pin into the duplex fabric layer.
This press felt construction has at least one significant shortcoming.
When the single layer fabric is cut, its yarns tend to fray somewhat at the cut.
Thus, when the felt is installed and operated on the paper machine, the frayed ends of the .finer mesh single layer fabric can interfere with the manner in which the cut portion of the butt layer (which is often a flap of bats layer material) overlays the base fabric. As such, paper formed with such a felt can have an inconsistent appearance and be more susceptible to breaking on the paper machine due to the presence of the seam of the felt. One approach to this problem is offered in International Application No. PCT/US98/19850, which discusses a press felt in which a band of cross machine direction yams formed of a "low melt" material is included at the seam of the single layer fabric. The low melt material can soften somewhat during heat-setting of the fabric, which can induce the cross machine direction yarns to agglomerate somewhat and reduce fraying.
Summary of the Invention In view of the foregoing, it is an object of the present invention to provide a press felt having a laminated base fabric with a reduced tendency for the fraying of yarns at the base fabric seam.
It is also an object of the present invention to provide such a press felt at a relatively low cost.
It is a further object of the present invention to provide a method for constructing such a press felt.
These and other objects are satisfied by the present invention, which is directed to a press felt that can have a reduced tendency to fray at the seam cut.
The press felt comprises: a paper side batt layer; a machine side batt layer;
and a base fabric layer sandwiched between the paper side batt layer and the machine side batt layer. The base fabric layer comprises a first fabric and a second fabric.
The first fabric includes machine direction yarns and cross machine direction yarns I ~ ., i r :: t ~"~i.;1~1.~-: ~~ ~ ~I . 51 ' ~ Ari,.~ney Docket No. 5689-257 interwoven with the machine direction yarns. The -first fabric has first and second ends with loops, wherein the loops of the first end are interdigitated with the loops of the second end, and the loops of said first and second ends receive a pin to form the first fabric into .an endless belt having a seam. The second fabric is formed into an endless belt overlying the first fabric and includes machine direction yarns and.
cmss machine direction yarns interwoven with the machine direction yens, wherein the machine direction yarns are formed of a low melt material. In this configuration, the low melt machine direction yarns of the second fabric may have a.reduced tendency to fray at the seam cut during prolonged operation.
Another aspect of the present invention is a papermaker's press felt comprising the paper side batt layer, machine side batt layer, and base fabric layer described above, wherein the second fabric includes a band overlying the pin seam that has no CMD yarns. This configuration can also assist in reducing fraying at the seam cut.
Brief Description of the Drawings Figure 1 is a schematic illustration of the press section of a paper machine employing a press felt of the present invention.
Figure 2 is an enlarged partial cutaway perspective view of the 20- press felt of Figure 1.
Figure 3 is a greatly enlarged side section view of the press felt of Figure 1.
Figure 4A is a greatly enlarged partial perspective view of the pin seam of the press felt of Figure 1 in a joined condition.
Figure 4B is an enlarged partial perspective view of the pin seam of Figure 4A in an unjoined position.
Figure 5 is a schematic representation of a process for constructing the press felt of Figure 1.
Detailed Description of the Invention The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown and described. This invention may, however, be I : r f ' j~~ll~.d~i,v ~~ I
Ah"..zey Docket No. 5689-257 embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like components throughout. Components and layers may be exaggerated for clarity.
As used herein, the terms "machine direction" (MD) and "cross machine direction" (CMD) refer, respectively, to a direction aligned with the direction of travel of the papermakers' fabric on a papermaking machine, and a direction parallel to the fabric surface and transverse to the direction of travel.
Also, both the flat weaving and endless weaving methods described hereinabove are well known in the art, and the term "endless belt" as used herein refers to belts made by either method.
Referring now to the drawings, a papermaking machine press section, designated broadly at 10, is illustrated in Figure 1. The press section 10 includes a press felt-14 that is installed upon and conveyed by a set of rollers 12.
In its travel, the felt 14 travels over a press roll 15. An opposed press roll 17 is positioned to, in conjunction with the felt 14 and press roll 15, form a nip N
between the press mils 15. ' In operation, a paper web P is conveyed from a forming section 1b through the nip N formed by the press rollers 15, 17, whereia pressure is applied to the paper web P by the press rolls 15,17. The pressure forces moisture from the paper web P that is absorbed by the felt 14. As the felt 14 is conveyed around its roller set 12, moisture is removed therefrom, and the felt 14 is conditioned by one or more suction boxes 20. ' Figures 2 and 3 illustrate an enlarged section of the felt 14. As can be seen in Figure 2, the felt 14 includes a laminated base fabric layer 22 which comprises two separate fabrics: namely, a lower fabric layer comprising a duplex fabric 24 and an upper fabric layer comprising a single layer fabric 36. The duplex fabric 24 includes two sets of machine direction yarns 26 and one set of cross machine direction yarns 28 interwoven with the machine direction yarns 26. The duplex fabric 24 is woven in a flat weave process; thus, in a flat condition, the duplex fabric 24 has two free ends 29a, 29b, one of which (29a) includes loops (formed by machine direction yarns 2~, and the other of which (29b) includes a~ ~i I .II I II
At~."ney Docket No. 5689-257 loops 32 formed by machine direction yarns 26. When the duplex fabric 24 is in an endless condition such as that illustrated in Figures 2 and 3, the loops 30, 32 are .
positioned in interdigitated fashion, and a pin 34 is inserted through the Ioops 30, 32 to join the ends 29a, 29b,of the duplex fabric 24 (see Figures 4A and 4B).
This fabric can be flat woven in a process such as that disclosed in U.S. Patent No.
5,476,123 to Rydin.
Those skilled in this art will recognize that other types of fabrics can be employed as the lower fabric layer of the base fabric layer 22 in the manner of the duplex fabric 24, including single layer fabrics, other duplex fabrics, and triplex fabrics i.e., those having two sets of machine direction yarns and two sets of cross machine direction yarns). Virtually any weave pattern known to those skilled in this art, such as the illustrated plain weave, twills, satins, and the like, can be used for this fabric layer. The lower fabric layer will typically, but not always, have a mesh that is somewhat more coarse than that of the upper fabric layer; it is preferred that the mesh of the lower fabric layer.be between about 30 to SO machine direction yarns and 50 to 100 cross machine direction yarns per inch.
The lower fabric layer should have the aforementioned loops 30, 32 at its ends 29a, 29b to enable it to be joined into an endless belt with the pin 34. The construction of the loops 30, 32 and pin 34 are known to those skilled in this art and need not be described in detail herein; exemplary loop and pin constructions are described in U.S. Patent Nos. 4,737,241 and 4,764,417 to Gulya. _.
Referring again to Figures 2 and 3, the single layer fabric 36 comprises machine direction yarns 38 interwoven with cross machine direction yarns 40 in a plain weave pattern. The machine direction yams 38 are formed of a low melt material that differs in composition from the material employed with the cross machine direction yarns 40 and the yarns of the duplex fabric 24. As used herein, the term "low melt" means that the yarns have a lower melting point than at least the cross machine direction yarns.40 of the upper fabric 36, and in many instances than the other yarns of both the upper and lower fabric layers. The melting point of the low melt yarns is preferably at least 25°C lower than that of the machine direction yarns 26 of the lower fabric layer 24. Exemplary low melt materials to be employed as machine direction yarns 38 include nylons (including nylon 6, nylon 6-6, nylon 6-10, nylon 6-12 and nylon 12, and blends and ~. . ~ . ~ ~, u~~~~ . ui i ~i At~,..ney Docket No. 5689-257 copolymers thereof), polyesters and copolymers thereof and polypropylene and copolymers thereof. It is preferred thaf the low melt material have a melting point of between about 130 and 200°C.
Those skilled in this art will recognize that other types of fabrics can be employed as the upper fabric layer of the base fabric layer 22 in the manner of the single layer fabric 36, including other single layer fabrics, duplex fabrics, and triplex fabrics. Virtually any weave pattern known to those skilled in this art, such as the illustrated plain weave, twills, satins, and the like, can be used for this fabric layer. The mesh of the upper fabric layer may vary from between about to 100 machine direction yarns and 16 to 100 cross machine direction yams per inch, but typically the mesh will be somewhat finer than that of the lower fabric layer. Those skilled in this art will also recognize that, although it may be preferred for cost reasons to employ low melt yarns as machine direction yarns only, low melt yarns can also be used as the cross machine direction yarns 40 of for some or all of the single layer fabric 36, or even as the machine direction yarns 26 or cross machine direction yarns of the duplex fabric 24.
Illustratively and preferably, the single layer fabric 3b includes a band 42 that includes no cross machine direction yarns 40. The band 42 should overlie the pin 34 of the duplex fabric 24. The band 42 is approximately 2 to inches with 8 inches being preferred in length i.e. the band 42 extends approximately 4 inches on either side of the pin 34). The presence of the band 42 .
eliminates CMD yams that might otherwise fray in the seam area.
Preferably, the single layer fabric 36 is woven in a flat weaving process that produces a fabric with two free ends. The single layer fabric 36 is formed into an endless belt through a joining process such as heat welding, which forms a weld line 46, although other methods of joining known in the art may also be employed. Alternatively, the single layer fabric 36 can be woven in an endless process so that the band 42 is formed during weaving.
The form of the yarns employed in the lower and upper fabric layers of the base fabric layer 24 can vary, depending upon the desired properties of the final press felt. For example, the yarns may be multifilament yams, monofilament yarns, twisted or cabled multifilament or monofilament yarns, spun yarns, or any combination thereof. Also, the materials from which the "non-low melt" yarns _7_ l I ~ I I,.. ~~ ~ ~I
At~".ney Docket No. 5689-257 employed in the fabric-layers are formed may be those commonly used in press felts, such as nylon, cotton, wool, polypropylene, polyester, aramid, polyamide, or the like, and blends and combinations thereof.
Referring again to Figures 2 and 3, the felt 14 also includes scrim S sheets 44a, 44b, 44c. The scrim sheet 44a is positioned between the double layer fabric 24 and the single layer fabric 36. The scrim sheet 44b is positioned directly beneath the double layer fabric 24. The scrim layer 44c is positioned directly above the single layer fabric 36. The scrim sheets 44a, 44b, 44c overlie the seam area of the felt 14, typically extending between about 4 to 10 inches on either side of the seam formed by the pin 34. Typically, the scrim sheets 44a, 44b, 44c comprise a non-woven, porous low melt nylon fabric.
Still refernng to Figures 2 and 3, the felt 14 also includes two batt layers: a machine side batt layer 50 and a paper side batt layer 52.
Illustratively and preferably, these batt layers 50, 52 are attached to the base fabric layer through a needling process, although other attachment techniques, such as heat bonding and adhesives, can also be used with the present invention. An exemplary needling process is illustrated and described in co-assigned and co-pending U.S.
Patent Application No. 09/359,213, the disclosure of which is hereby incorporated herein by reference in its entirety.
The machine side and paper side batt layers 50, 52 should be formed of material, such as a synthetic fiber like acrylic, aramid, polyester, or nylon, or a natural fiber such as wool, that assists in wicking water away from the base fabric layer 22. Preferred materials for the batt layers 50, 52 include polyamide, polyester and blends thereof. The weight and thickness of the batt layers 50, 52 can vary, although it is preferably that the ratio of batt weight to fabric weight is about between about 0.5 and 2.0, with 1.0 being more preferred.
Also, in some embodiments, it may be desirable to have additional batt layers or to omit either or both of the batt layers 50, 52. Notably, the machine side belt layer 50 has an open area 50 below the pin 34 in which batt has been removed (Figure 3).
The felt 14 also includes a seam cut 48. The seam cut 48 extends through the paper side batt layer 52, the single layer fabric 36, and the machine "
side batt layer 50. Illustratively and preferably, the seam cut 48 is made at an _g_ ~ . ~~i 6 .. .II I t1 Attorney Docket No. 5689-257 angle of between about 30 and 80 degrees to the plane of the base fabric layer 22, and a flap 52a is formed by loosening the portion of the paper side butt layer adjacent the seam cut 48. This process is described in detail in the aforementioned U.S. Patents to Gulya and Lilja. Of course, no cut is necessary for the duplex fabric 24, as the pin 34 can simply be removed to enable the ends 29a, 29b of the duplex fabric 24 to be separated.
Figure 5 illustrates an exemplary manufacturing process for the felt 14. Initially, the duplex fabric 24 is flat woven such that machine direction loops 30, 32 are created on the ends 29a, 29b. A pin 60 (which is typically larger and less flexible than the pin 34 described above) is inserted through the loops 30, 32 (as they are interdigitated) to join them and thereby form the duplex fabric 24 into an endless belt. Separately, the single layer fabric 36 is woven in a flat weaving or endless weaving process. If flat woven, the single layer fabric 36 is formed into an endless belt with a heat welding process, such as one that employs heat or ultrasonic radiation. The single layer fabric 36 is then positioned to overlie the duplex fabric 24 such that the band 42 that lacks cross machine direction yams overlies the pin 34, the scrim sheets 44a, 44b, 44c are positioned over the seam area, and the machine side and paper side batt layers 50, 52 are needled to the base fabric layer 22 (the open area 50a is typically created by removing fiber with a brush and tweezers).
Once the batt layers 50, 52 have been added, the entire felt 14 is then heat treated at a temperature sufficient to cause softening of the machine direction yarns 38 formed of low melt material without unduly softening the other yarns of the base fabric 22. Typically, the heat treatment is carried out at a temperature of between about 130° to 200° C. The pin 60 is then removed, and the seam cut 48 is formed with blades or other cutting devices through the paper side batt layer 52 and the single layer fabric 36. The felt 14 can then be shipped in its flat form to a paper null, where the pin 34 can be inserted into the machine direction loops 30, 32 as the felt 14 is installed on the upper rolls 12.
Importantly, when the seam cut 48 is made, the yarns of the single layer fabric 36, and in particular the machine direction yarns 38, can have a far lower tendency to fray than the fabrics of prior art felts. This reduced fraying is the result of the inclusion of the low melt machine direction yarns 38. As _g_ i ~ ~ i ~t:~ ~~i ~ ~~ i Att~~ney Docket No. 5689-257 described, during the heat treatment of the felt 14, the softening of the low melt machine direction yarns 38 causes the agglomeration of the machine direction yarns 38 and the fibers of the paper side batt layer 52. As a result, the flap 52a adjacent to the seam cut 48 can lay uniformly, even during operation, which has not always been the case for prior art fabrics.
The invention will now be more particularly described in the following non-limiting example.
EXAMPLE
A press felt was constructed according to the following parameters MD yarns CMD Mesh yarns Count Base Fabric LayerSize Material Size Material (inches) (inches)s Duplex Layer 0.015 Nylon 0.015 Nylon 40x48 Single Layer* 0.014 Nylon 0.008 Nylon 40x24 .
* The single layer fabric was woven without CMD yams in a 8 inch wide band that was positioned directly over the pin seam of the duplex fabric.
Batt Layers Material Weight (g/m=) Machine Side Nylon staple 150 Paper Side Nylon staple 780 Heat Treatment: 3 minutes at 175°C
The resulting press felt successfully produced linerboard paper.
The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention.
Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following -=-claims, with equivalents of the claims to be included therein. In the claims, means-~~, ;~,.I , ~i I fl At~",ney Docket No. 5689-257 plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.
.. . ~.
' ~ . Ah"..~ey Docket No. 5689-257 PIN SEAMED PAPERMAI~R'S PRESS FELT WITH LAMINATED BASE
FABRIC HAVING LOW MELT MATERIAL MACHINE DIRECTION
YARNS
Field of the Invention The present invention relates generally to papermaking, and more particularly to fabrics used in papermaking.
Background of the Invention In the conventional fourdrinier papermaking process, a water slurry, or suspension, of celluIosic fibers (known as the paper "stock") is fed onto the top of the upper run of an endless belt of woven wire and/or synthetic material that travels between two or more rollers. The belt, often referred to as a "forming fabric," provides, a papermaking surface on the upper surface of its upper run which operates as a filter to separate the cellulosic fibers of the paper stock from the aqueous medium, thereby forming a wet paper web. The aqueous medium drains through mesh openings of the forming fabric, known as drainage holes, by gravity alone or with assistance from one or more suction boxes located on the lower surface i.e. the "machine side") of the upper run of the fabric.
After leaving the forming section, the paper web is transferred to a press section -of the paper machine, in which it is passed thmugh the nips of one or more pairs. of pressure rollers covered with another fabric, typically referred to as a "press felt." Pressure from the rollers removes additional moisture from the web;
, the moisture removal is often enhanced by the presence of a "batt" layer on the press felt. The paper is then conveyed to a drier section for further moisture removal. After drying, the paper is ready for secondary processing and packaging.
Press felts typically include one or more base fabric layers; these can be "flat-woven" and formed after weaving into an endless belt, or can be woven in endless form. Generally, the flat-woven process is preferred, as it is _:-typically less expensive and more versatile than the endless weaving process.
~ ~ ~ a i L~r~~~a ~ V~ ~ , ~~
At~"~ney Docket No. 5689-2S7 Also, in many instances the felt is cut widthwise and reattached to simplify installation on a paper machine, in which case some of the advantages of endless weaving (such as the absence of a seam in the fabric) are lost.
Of course, flat weaving a fabric of a base layer requires that S provision be made for joining it into endless belts. Such joints should be constructed in such a manner that they are sufficiently strong to withstand the extreme load, tanperature, and wear conditions the press felt experiences, yet do not cause the surface of the press felt above the seam to unduly mark the paper.
One popular method of joining the base fabric of a press felt is to form loops with machinedirection yarns on each end of the base fabric. To form the flat-woven base fabric into an endless belt, the ends of the fabric are placed adjacent to each other, with each of the loops on one end positioned between two loops on the other end in interdigitating fashion. A "pin" (usually formed of mutilfilament polymeric fiber strands) is then inserted into all of the loops to join the ends. After the bait 1 S layers) are needled or otherwise attached to the base'layer, the batt layers) are cut at the seam location, the pin is removed, and the finished press felt is shipped to a paper mill. Once at the paper mill, the press felt can be installed by placing it onto a paper machine, then inserting another (usually more.flexible) multifilament pin into the loops. Examples of this type of seam are described in U.S. Patent Nos. 4, 764,417 and 4,737,241 to Gulya, 4,601,785 to Lilja et al., and 5,476,123 to Rydin the disclosures of which are hereby incorporated herein by reference in their entireties.
In some press felts, the base fabric layer itself contains multiple fabric layers i.e., is a "laminated." base layer). For example, a felt may contain a 2S "duplex" fabric i.e., a fabric having upper and lower sets of machine direction yarns interwoven with at least one set, of cross machine direction yarns -also known as a "double layer" fabric) as well as a finer mesh single layer fabric i.e., a fabric having only one set each of machine direction yarns and cross machine -direction yarns). This combination provides a good balance of strength and durability to the felt with relatively little marking. Typically, the felt is constructed by flat weaving the duplex fabric, endless weaving the single layer fabric, joining the duplex fabric with a pin as described above, overlaying the single layer fabric over the duplex fabric, needling both fabric layers with batt to form machine side, ;, ~:~,.~,.I: , ~i I . ~I
At~.,.ney Docket No. 5689-257 and paper side batt layers, removing the pin from the double layer fabric and cutting the batt layers and the single layer fabric at the seam to form a flat . structure. Once at the paper mall, the felt is installed on the papermaking machine by inserting a new, typically thinner and more flexible pin into the duplex fabric layer.
This press felt construction has at least one significant shortcoming.
When the single layer fabric is cut, its yarns tend to fray somewhat at the cut.
Thus, when the felt is installed and operated on the paper machine, the frayed ends of the .finer mesh single layer fabric can interfere with the manner in which the cut portion of the butt layer (which is often a flap of bats layer material) overlays the base fabric. As such, paper formed with such a felt can have an inconsistent appearance and be more susceptible to breaking on the paper machine due to the presence of the seam of the felt. One approach to this problem is offered in International Application No. PCT/US98/19850, which discusses a press felt in which a band of cross machine direction yams formed of a "low melt" material is included at the seam of the single layer fabric. The low melt material can soften somewhat during heat-setting of the fabric, which can induce the cross machine direction yarns to agglomerate somewhat and reduce fraying.
Summary of the Invention In view of the foregoing, it is an object of the present invention to provide a press felt having a laminated base fabric with a reduced tendency for the fraying of yarns at the base fabric seam.
It is also an object of the present invention to provide such a press felt at a relatively low cost.
It is a further object of the present invention to provide a method for constructing such a press felt.
These and other objects are satisfied by the present invention, which is directed to a press felt that can have a reduced tendency to fray at the seam cut.
The press felt comprises: a paper side batt layer; a machine side batt layer;
and a base fabric layer sandwiched between the paper side batt layer and the machine side batt layer. The base fabric layer comprises a first fabric and a second fabric.
The first fabric includes machine direction yarns and cross machine direction yarns I ~ ., i r :: t ~"~i.;1~1.~-: ~~ ~ ~I . 51 ' ~ Ari,.~ney Docket No. 5689-257 interwoven with the machine direction yarns. The -first fabric has first and second ends with loops, wherein the loops of the first end are interdigitated with the loops of the second end, and the loops of said first and second ends receive a pin to form the first fabric into .an endless belt having a seam. The second fabric is formed into an endless belt overlying the first fabric and includes machine direction yarns and.
cmss machine direction yarns interwoven with the machine direction yens, wherein the machine direction yarns are formed of a low melt material. In this configuration, the low melt machine direction yarns of the second fabric may have a.reduced tendency to fray at the seam cut during prolonged operation.
Another aspect of the present invention is a papermaker's press felt comprising the paper side batt layer, machine side batt layer, and base fabric layer described above, wherein the second fabric includes a band overlying the pin seam that has no CMD yarns. This configuration can also assist in reducing fraying at the seam cut.
Brief Description of the Drawings Figure 1 is a schematic illustration of the press section of a paper machine employing a press felt of the present invention.
Figure 2 is an enlarged partial cutaway perspective view of the 20- press felt of Figure 1.
Figure 3 is a greatly enlarged side section view of the press felt of Figure 1.
Figure 4A is a greatly enlarged partial perspective view of the pin seam of the press felt of Figure 1 in a joined condition.
Figure 4B is an enlarged partial perspective view of the pin seam of Figure 4A in an unjoined position.
Figure 5 is a schematic representation of a process for constructing the press felt of Figure 1.
Detailed Description of the Invention The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown and described. This invention may, however, be I : r f ' j~~ll~.d~i,v ~~ I
Ah"..zey Docket No. 5689-257 embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like components throughout. Components and layers may be exaggerated for clarity.
As used herein, the terms "machine direction" (MD) and "cross machine direction" (CMD) refer, respectively, to a direction aligned with the direction of travel of the papermakers' fabric on a papermaking machine, and a direction parallel to the fabric surface and transverse to the direction of travel.
Also, both the flat weaving and endless weaving methods described hereinabove are well known in the art, and the term "endless belt" as used herein refers to belts made by either method.
Referring now to the drawings, a papermaking machine press section, designated broadly at 10, is illustrated in Figure 1. The press section 10 includes a press felt-14 that is installed upon and conveyed by a set of rollers 12.
In its travel, the felt 14 travels over a press roll 15. An opposed press roll 17 is positioned to, in conjunction with the felt 14 and press roll 15, form a nip N
between the press mils 15. ' In operation, a paper web P is conveyed from a forming section 1b through the nip N formed by the press rollers 15, 17, whereia pressure is applied to the paper web P by the press rolls 15,17. The pressure forces moisture from the paper web P that is absorbed by the felt 14. As the felt 14 is conveyed around its roller set 12, moisture is removed therefrom, and the felt 14 is conditioned by one or more suction boxes 20. ' Figures 2 and 3 illustrate an enlarged section of the felt 14. As can be seen in Figure 2, the felt 14 includes a laminated base fabric layer 22 which comprises two separate fabrics: namely, a lower fabric layer comprising a duplex fabric 24 and an upper fabric layer comprising a single layer fabric 36. The duplex fabric 24 includes two sets of machine direction yarns 26 and one set of cross machine direction yarns 28 interwoven with the machine direction yarns 26. The duplex fabric 24 is woven in a flat weave process; thus, in a flat condition, the duplex fabric 24 has two free ends 29a, 29b, one of which (29a) includes loops (formed by machine direction yarns 2~, and the other of which (29b) includes a~ ~i I .II I II
At~."ney Docket No. 5689-257 loops 32 formed by machine direction yarns 26. When the duplex fabric 24 is in an endless condition such as that illustrated in Figures 2 and 3, the loops 30, 32 are .
positioned in interdigitated fashion, and a pin 34 is inserted through the Ioops 30, 32 to join the ends 29a, 29b,of the duplex fabric 24 (see Figures 4A and 4B).
This fabric can be flat woven in a process such as that disclosed in U.S. Patent No.
5,476,123 to Rydin.
Those skilled in this art will recognize that other types of fabrics can be employed as the lower fabric layer of the base fabric layer 22 in the manner of the duplex fabric 24, including single layer fabrics, other duplex fabrics, and triplex fabrics i.e., those having two sets of machine direction yarns and two sets of cross machine direction yarns). Virtually any weave pattern known to those skilled in this art, such as the illustrated plain weave, twills, satins, and the like, can be used for this fabric layer. The lower fabric layer will typically, but not always, have a mesh that is somewhat more coarse than that of the upper fabric layer; it is preferred that the mesh of the lower fabric layer.be between about 30 to SO machine direction yarns and 50 to 100 cross machine direction yarns per inch.
The lower fabric layer should have the aforementioned loops 30, 32 at its ends 29a, 29b to enable it to be joined into an endless belt with the pin 34. The construction of the loops 30, 32 and pin 34 are known to those skilled in this art and need not be described in detail herein; exemplary loop and pin constructions are described in U.S. Patent Nos. 4,737,241 and 4,764,417 to Gulya. _.
Referring again to Figures 2 and 3, the single layer fabric 36 comprises machine direction yarns 38 interwoven with cross machine direction yarns 40 in a plain weave pattern. The machine direction yams 38 are formed of a low melt material that differs in composition from the material employed with the cross machine direction yarns 40 and the yarns of the duplex fabric 24. As used herein, the term "low melt" means that the yarns have a lower melting point than at least the cross machine direction yarns.40 of the upper fabric 36, and in many instances than the other yarns of both the upper and lower fabric layers. The melting point of the low melt yarns is preferably at least 25°C lower than that of the machine direction yarns 26 of the lower fabric layer 24. Exemplary low melt materials to be employed as machine direction yarns 38 include nylons (including nylon 6, nylon 6-6, nylon 6-10, nylon 6-12 and nylon 12, and blends and ~. . ~ . ~ ~, u~~~~ . ui i ~i At~,..ney Docket No. 5689-257 copolymers thereof), polyesters and copolymers thereof and polypropylene and copolymers thereof. It is preferred thaf the low melt material have a melting point of between about 130 and 200°C.
Those skilled in this art will recognize that other types of fabrics can be employed as the upper fabric layer of the base fabric layer 22 in the manner of the single layer fabric 36, including other single layer fabrics, duplex fabrics, and triplex fabrics. Virtually any weave pattern known to those skilled in this art, such as the illustrated plain weave, twills, satins, and the like, can be used for this fabric layer. The mesh of the upper fabric layer may vary from between about to 100 machine direction yarns and 16 to 100 cross machine direction yams per inch, but typically the mesh will be somewhat finer than that of the lower fabric layer. Those skilled in this art will also recognize that, although it may be preferred for cost reasons to employ low melt yarns as machine direction yarns only, low melt yarns can also be used as the cross machine direction yarns 40 of for some or all of the single layer fabric 36, or even as the machine direction yarns 26 or cross machine direction yarns of the duplex fabric 24.
Illustratively and preferably, the single layer fabric 3b includes a band 42 that includes no cross machine direction yarns 40. The band 42 should overlie the pin 34 of the duplex fabric 24. The band 42 is approximately 2 to inches with 8 inches being preferred in length i.e. the band 42 extends approximately 4 inches on either side of the pin 34). The presence of the band 42 .
eliminates CMD yams that might otherwise fray in the seam area.
Preferably, the single layer fabric 36 is woven in a flat weaving process that produces a fabric with two free ends. The single layer fabric 36 is formed into an endless belt through a joining process such as heat welding, which forms a weld line 46, although other methods of joining known in the art may also be employed. Alternatively, the single layer fabric 36 can be woven in an endless process so that the band 42 is formed during weaving.
The form of the yarns employed in the lower and upper fabric layers of the base fabric layer 24 can vary, depending upon the desired properties of the final press felt. For example, the yarns may be multifilament yams, monofilament yarns, twisted or cabled multifilament or monofilament yarns, spun yarns, or any combination thereof. Also, the materials from which the "non-low melt" yarns _7_ l I ~ I I,.. ~~ ~ ~I
At~".ney Docket No. 5689-257 employed in the fabric-layers are formed may be those commonly used in press felts, such as nylon, cotton, wool, polypropylene, polyester, aramid, polyamide, or the like, and blends and combinations thereof.
Referring again to Figures 2 and 3, the felt 14 also includes scrim S sheets 44a, 44b, 44c. The scrim sheet 44a is positioned between the double layer fabric 24 and the single layer fabric 36. The scrim sheet 44b is positioned directly beneath the double layer fabric 24. The scrim layer 44c is positioned directly above the single layer fabric 36. The scrim sheets 44a, 44b, 44c overlie the seam area of the felt 14, typically extending between about 4 to 10 inches on either side of the seam formed by the pin 34. Typically, the scrim sheets 44a, 44b, 44c comprise a non-woven, porous low melt nylon fabric.
Still refernng to Figures 2 and 3, the felt 14 also includes two batt layers: a machine side batt layer 50 and a paper side batt layer 52.
Illustratively and preferably, these batt layers 50, 52 are attached to the base fabric layer through a needling process, although other attachment techniques, such as heat bonding and adhesives, can also be used with the present invention. An exemplary needling process is illustrated and described in co-assigned and co-pending U.S.
Patent Application No. 09/359,213, the disclosure of which is hereby incorporated herein by reference in its entirety.
The machine side and paper side batt layers 50, 52 should be formed of material, such as a synthetic fiber like acrylic, aramid, polyester, or nylon, or a natural fiber such as wool, that assists in wicking water away from the base fabric layer 22. Preferred materials for the batt layers 50, 52 include polyamide, polyester and blends thereof. The weight and thickness of the batt layers 50, 52 can vary, although it is preferably that the ratio of batt weight to fabric weight is about between about 0.5 and 2.0, with 1.0 being more preferred.
Also, in some embodiments, it may be desirable to have additional batt layers or to omit either or both of the batt layers 50, 52. Notably, the machine side belt layer 50 has an open area 50 below the pin 34 in which batt has been removed (Figure 3).
The felt 14 also includes a seam cut 48. The seam cut 48 extends through the paper side batt layer 52, the single layer fabric 36, and the machine "
side batt layer 50. Illustratively and preferably, the seam cut 48 is made at an _g_ ~ . ~~i 6 .. .II I t1 Attorney Docket No. 5689-257 angle of between about 30 and 80 degrees to the plane of the base fabric layer 22, and a flap 52a is formed by loosening the portion of the paper side butt layer adjacent the seam cut 48. This process is described in detail in the aforementioned U.S. Patents to Gulya and Lilja. Of course, no cut is necessary for the duplex fabric 24, as the pin 34 can simply be removed to enable the ends 29a, 29b of the duplex fabric 24 to be separated.
Figure 5 illustrates an exemplary manufacturing process for the felt 14. Initially, the duplex fabric 24 is flat woven such that machine direction loops 30, 32 are created on the ends 29a, 29b. A pin 60 (which is typically larger and less flexible than the pin 34 described above) is inserted through the loops 30, 32 (as they are interdigitated) to join them and thereby form the duplex fabric 24 into an endless belt. Separately, the single layer fabric 36 is woven in a flat weaving or endless weaving process. If flat woven, the single layer fabric 36 is formed into an endless belt with a heat welding process, such as one that employs heat or ultrasonic radiation. The single layer fabric 36 is then positioned to overlie the duplex fabric 24 such that the band 42 that lacks cross machine direction yams overlies the pin 34, the scrim sheets 44a, 44b, 44c are positioned over the seam area, and the machine side and paper side batt layers 50, 52 are needled to the base fabric layer 22 (the open area 50a is typically created by removing fiber with a brush and tweezers).
Once the batt layers 50, 52 have been added, the entire felt 14 is then heat treated at a temperature sufficient to cause softening of the machine direction yarns 38 formed of low melt material without unduly softening the other yarns of the base fabric 22. Typically, the heat treatment is carried out at a temperature of between about 130° to 200° C. The pin 60 is then removed, and the seam cut 48 is formed with blades or other cutting devices through the paper side batt layer 52 and the single layer fabric 36. The felt 14 can then be shipped in its flat form to a paper null, where the pin 34 can be inserted into the machine direction loops 30, 32 as the felt 14 is installed on the upper rolls 12.
Importantly, when the seam cut 48 is made, the yarns of the single layer fabric 36, and in particular the machine direction yarns 38, can have a far lower tendency to fray than the fabrics of prior art felts. This reduced fraying is the result of the inclusion of the low melt machine direction yarns 38. As _g_ i ~ ~ i ~t:~ ~~i ~ ~~ i Att~~ney Docket No. 5689-257 described, during the heat treatment of the felt 14, the softening of the low melt machine direction yarns 38 causes the agglomeration of the machine direction yarns 38 and the fibers of the paper side batt layer 52. As a result, the flap 52a adjacent to the seam cut 48 can lay uniformly, even during operation, which has not always been the case for prior art fabrics.
The invention will now be more particularly described in the following non-limiting example.
EXAMPLE
A press felt was constructed according to the following parameters MD yarns CMD Mesh yarns Count Base Fabric LayerSize Material Size Material (inches) (inches)s Duplex Layer 0.015 Nylon 0.015 Nylon 40x48 Single Layer* 0.014 Nylon 0.008 Nylon 40x24 .
* The single layer fabric was woven without CMD yams in a 8 inch wide band that was positioned directly over the pin seam of the duplex fabric.
Batt Layers Material Weight (g/m=) Machine Side Nylon staple 150 Paper Side Nylon staple 780 Heat Treatment: 3 minutes at 175°C
The resulting press felt successfully produced linerboard paper.
The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention.
Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following -=-claims, with equivalents of the claims to be included therein. In the claims, means-~~, ;~,.I , ~i I fl At~",ney Docket No. 5689-257 plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.
Claims (26)
1. A papermaker's press felt, comprising:
a paper side batt layer;
a machine side batt layer; and a base fabric layer sandwiched between said paper side batt layer and said machine side batt layer, said base fabric layer comprising a first fabric and a second fabric;
said first fabric including machine direction yarns and cross machine direction yarns interwoven with said machine direction yarns, said first fabric having first and second ends with loops, said loops of said first end being interdigitated with said loops of said second end, said loops of said first and second ends receiving a pin to form said first fabric into an endless belt having a seam;
said second fabric formed into an endless belt overlying said first fabric and including machine direction yarns and cross machine direction yarns interwoven with said machine direction yarns, wherein said machine direction yarns are formed of a low melt material.
a paper side batt layer;
a machine side batt layer; and a base fabric layer sandwiched between said paper side batt layer and said machine side batt layer, said base fabric layer comprising a first fabric and a second fabric;
said first fabric including machine direction yarns and cross machine direction yarns interwoven with said machine direction yarns, said first fabric having first and second ends with loops, said loops of said first end being interdigitated with said loops of said second end, said loops of said first and second ends receiving a pin to form said first fabric into an endless belt having a seam;
said second fabric formed into an endless belt overlying said first fabric and including machine direction yarns and cross machine direction yarns interwoven with said machine direction yarns, wherein said machine direction yarns are formed of a low melt material.
2. The papermaker's press felt defined in Claim 1, wherein said second fabric includes a band overlying said seam of said first fabric that has no cross machine direction yarns.
3. The papermaker's press felt defined in Claim 1, said paper side batt layer and said machine side batt layer are needled to said base fabric layer.
4. The papermaker's press felt defined in Claim 1, wherein said first fabric comprises a duplex fabric.
5. The papermaker's press felt defined in Claim 1, wherein said second fabric comprises a single layer fabric.
6. The papermaker's press felt defined in Claim 1, wherein said low melt material is selected from the group consisting of nylon and nylon copolymer.
7. The papermaker's press felt defined in Claim 1, wherein said first fabric layer forms a coarser mesh than said second fabric.
8. The papermaker's press felt defined in Claim 1, wherein each of said paper side batt layer, said machine side batt layer; and said second fabric includes a cut corresponding to said first fabric seam to enable said press felt to take a flat condition upon removal of said pin.
9. The papermaker's press felt defined in Claim 8, wherein said cut is oriented at an angle of between about 30 and 80 degrees relative to the plane of the base fabric layer.
10. A papermaker's press felt, comprising:
a paper side batt layer;
a machine side batt layer; and a base fabric layer sandwiched between said paper side batt layer and said machine side batt layer, said base fabric layer comprising a first fabric and a second fabric;
said first fabric including machine direction yarns and cross machine direction yarns interwoven with said machine direction yarns, said first fabric having first and second ends with loops, said loops of said first end being interdigitated with said loops of said second end, said loops of said first and second ends receiving a pin to form said first fabric into an endless belt having a seam;
said second fabric formed into an endless belt overlying said first fabric and including machine direction yarns and cross machine direction yarns interwoven with said machine direction yarns, said second fabric including a hand overlying said seam that has no CMD yarns.
a paper side batt layer;
a machine side batt layer; and a base fabric layer sandwiched between said paper side batt layer and said machine side batt layer, said base fabric layer comprising a first fabric and a second fabric;
said first fabric including machine direction yarns and cross machine direction yarns interwoven with said machine direction yarns, said first fabric having first and second ends with loops, said loops of said first end being interdigitated with said loops of said second end, said loops of said first and second ends receiving a pin to form said first fabric into an endless belt having a seam;
said second fabric formed into an endless belt overlying said first fabric and including machine direction yarns and cross machine direction yarns interwoven with said machine direction yarns, said second fabric including a hand overlying said seam that has no CMD yarns.
11. The papermaker's press felt defined in Claim 10, said paper side butt layer and said machine side batt layer are needled to said base fabric layer.
12. The papermaker's press felt defined in Claim 10, wherein said first fabric comprises a duplex fabric.
13. The papermaker's press felt defined in Claim 10, wherein said second fabric comprises a single layer fabric.
14. The papermaker's press felt defined in Claim 10, wherein said low melt material is selected from the group consisting of nylon and nylon copolymer.
15. The papermaker's press felt defined in Claim 10, wherein said first fabric layer forms a coarser mesh than said second fabric.
16. The papermaker's press felt defined in Claim 10, wherein each of said paper side batt layer, said machine side batt layer, and said second fabric includes a cut corresponding to said first fabric seam to enable said press felt to take a flat condition upon removal of said pin.
17. The papermaker's press felt defined in Claim 16, wherein said cut is oriented at an angle of between about 30 and 80 degrees relative.
to the plane of the base fabric layer.
to the plane of the base fabric layer.
18. A method of constructing a papermaker's press felt having a laminated base fabric layer, said method comprising the steps of:
interweaving machine direction yarns and cross machine direction yarns to form a first fabric, said first fabric having first and second ends with loops;
positioning the loops of said first and second ends of said first fabric in interdigitated relationship;
inserting a pin into said loops to farm a seam that joins the first and second ends of said first fabric, thereby forming said first fabric into an endless belt;
interweaving machine direction yarns and cross machine direction yarns to form a second fabric, wherein said machine direction yarns are formed of a low melt material;
attaching said second fabric to said first fabric;
heating said low melt band to cause said low melt material to soften; and cutting a seam through said low melt band that corresponds to said seam of said first fabric.
interweaving machine direction yarns and cross machine direction yarns to form a first fabric, said first fabric having first and second ends with loops;
positioning the loops of said first and second ends of said first fabric in interdigitated relationship;
inserting a pin into said loops to farm a seam that joins the first and second ends of said first fabric, thereby forming said first fabric into an endless belt;
interweaving machine direction yarns and cross machine direction yarns to form a second fabric, wherein said machine direction yarns are formed of a low melt material;
attaching said second fabric to said first fabric;
heating said low melt band to cause said low melt material to soften; and cutting a seam through said low melt band that corresponds to said seam of said first fabric.
19. The method defined in Claim 18, further comprising the step of attaching a first batt layer to overlie said second fabric layer.
20. The method defined in Claim 19, wherein said cutting step further comprises cutting said first batt layer to form a seam therein.
21. The method defined in Claim 19, further comprising the step of attaching a second batt layer to underlie said first fabric layer.
22. The method defined in Claim 21, wherein said cutting step further comprises cutting said second batt layer to form a seam therein.
23. The method defined in Claim 18, further comprising the step of removing the pin from said first fabric after said heating step and prior to said cutting step.
24. The method defined in Claim 18, wherein said heating step comprises heating the low melt material at a temperature of between about 130°C
and 200°.
and 200°.
25. The method defined in Claim 18, wherein said step of interweaving said second fabric comprises flat-weaving said second fabric.
26. The method defined in Claim 18, further comprising the step of heat welding said second fabric to join ends thereof and thereby form said second fabric into an endless belt.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US88543001A | 2001-06-20 | 2001-06-20 | |
| US09/885,430 | 2001-06-20 |
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|---|---|
| CA2391027A1 true CA2391027A1 (en) | 2002-12-20 |
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ID=25386891
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002391027A Abandoned CA2391027A1 (en) | 2001-06-20 | 2002-06-19 | Pin seamed papermaker's press felt with laminated base fabric having low melt material machine direction yarns |
Country Status (11)
| Country | Link |
|---|---|
| EP (1) | EP1270807B1 (en) |
| JP (1) | JP2003096685A (en) |
| KR (1) | KR20020097031A (en) |
| CN (1) | CN1396339A (en) |
| AT (1) | ATE315682T1 (en) |
| AU (1) | AU4887702A (en) |
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| CA (1) | CA2391027A1 (en) |
| DE (1) | DE60208607D1 (en) |
| ES (1) | ES2257488T3 (en) |
| MX (1) | MXPA02006129A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ZA200604959B (en) * | 2003-12-15 | 2008-02-27 | Albany Int Corp | Pintle for spiral fabrics |
| US7229531B2 (en) * | 2004-05-12 | 2007-06-12 | Albany International Corp. | Method of seaming a multiaxial papermaking fabric to prevent yarn migration |
| US7455752B2 (en) * | 2004-07-22 | 2008-11-25 | Albany International Corp. | Semi-permeable fabrics for transfer belt and press fabric applications |
| US20060068665A1 (en) * | 2004-09-29 | 2006-03-30 | Heinz Pernegger | Seamed felt for forming fiber cement articles and related methods |
| US7384513B2 (en) * | 2004-11-11 | 2008-06-10 | Albany International Corp. | Forming fabrics |
| US20130008552A1 (en) | 2011-07-06 | 2013-01-10 | Hans Peter Breuer | Felt for forming fiber cement articles and related methods |
| DE102019111441A1 (en) * | 2019-05-03 | 2020-11-05 | Voith Patent Gmbh | Covering and use in a tissue machine |
| EP3963135A1 (en) * | 2019-05-03 | 2022-03-09 | Voith Patent GmbH | Seamed felt and use of the seamed felt in a tissue machine |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5897745A (en) * | 1994-06-29 | 1999-04-27 | The Procter & Gamble Company | Method of wet pressing tissue paper |
| AU9503098A (en) * | 1998-09-24 | 2000-04-10 | Weavexx Corporation | Pin seamed papermaker's press felt with low melt material band in laminated basefabric |
-
2002
- 2002-06-19 CA CA002391027A patent/CA2391027A1/en not_active Abandoned
- 2002-06-19 CN CN02128612A patent/CN1396339A/en active Pending
- 2002-06-20 AU AU48877/02A patent/AU4887702A/en not_active Abandoned
- 2002-06-20 ES ES02013714T patent/ES2257488T3/en not_active Expired - Lifetime
- 2002-06-20 MX MXPA02006129A patent/MXPA02006129A/en active IP Right Grant
- 2002-06-20 DE DE60208607T patent/DE60208607D1/en not_active Expired - Lifetime
- 2002-06-20 BR BR0202331-8A patent/BR0202331A/en not_active IP Right Cessation
- 2002-06-20 EP EP02013714A patent/EP1270807B1/en not_active Expired - Lifetime
- 2002-06-20 KR KR1020020034698A patent/KR20020097031A/en not_active Application Discontinuation
- 2002-06-20 JP JP2002179716A patent/JP2003096685A/en active Pending
- 2002-06-20 AT AT02013714T patent/ATE315682T1/en not_active IP Right Cessation
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| AU4887702A (en) | 2003-01-02 |
| BR0202331A (en) | 2003-04-15 |
| ES2257488T3 (en) | 2006-08-01 |
| DE60208607D1 (en) | 2006-04-06 |
| JP2003096685A (en) | 2003-04-03 |
| EP1270807A1 (en) | 2003-01-02 |
| KR20020097031A (en) | 2002-12-31 |
| ATE315682T1 (en) | 2006-02-15 |
| MXPA02006129A (en) | 2003-10-06 |
| CN1396339A (en) | 2003-02-12 |
| EP1270807B1 (en) | 2006-01-11 |
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Legal Events
| Date | Code | Title | Description |
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| FZDE | Discontinued |