HIGH STABILITY STACKED WARP YARN DRYER FABRIC WITH LONG WARP FLOATS
20180347114 ยท 2018-12-06
Assignee
Inventors
Cpc classification
D10B2331/04
TEXTILES; PAPER
D10B2331/301
TEXTILES; PAPER
D03D13/004
TEXTILES; PAPER
International classification
D21F1/00
TEXTILES; PAPER
Abstract
An industrial textile is provided, preferably suitable for use as a dryer fabric in a papermaking machine. The industrial textile has first and second surfaces and is defined by first and second systems of warp yarns interwoven with a system of weft yarns in a repeating pattern. In the repeating pattern, each of the warp yarns in the first system of warp yarns is interwoven with the system of weft yarns with a float on the first surface over at least 5 of the weft yarns, under 1 of the weft yarns, over 1 of the weft yarns, and under 1 of the weft yarns. Additionally, each of the warp yarns in the second system of warp yarns is interwoven with the system of weft yarns with a float on the second surface under at least 5 of the weft yarns, over 1 of the weft yarns, under 1 of the weft yarns, and over 1 of the weft yarns in the repeating pattern. Each of the warp yarns of the first system of warp yarns is stacked over a corresponding one of the warp yarns of the second system of warp yarns to form stacked pairs of the warp yarns.
Claims
1. An industrial textile having first and second surfaces, the textile comprising: first and second systems of warp yarns interwoven with a system of weft yarns in a repeating pattern in which: each of the warp yarns in the first system of warp yarns is interwoven with the system of weft yarns on the first surface over at least 5 of the weft yarns, under 1 of the weft yarns, over 1 of the weft yarns, and under 1 of the weft yarns in the repeating pattern forming a float on the first surface over the at least 5 of the weft yarns, each of the warp yarns in the second system of warp yarns is interwoven with the system of weft yarns on the second surface under at least 5 of the weft yarns, over 1 of the weft yarns, under 1 of the weft yarns and over 1 of the weft yarns in the repeating pattern forming a float on the second surface under the at least 5 of the weft yarns, and each of the warp yarns of the first system of warp yarns is stacked over a corresponding one of the warp yarns of the second system of warp yarns to form stacked pairs of the warp yarns.
2. The industrial textile of claim 1, wherein the float on the first surface is over 7 weft yarns, and the float on the second surface is under 7 weft yarns.
3. The industrial textile of claim 1, wherein the system of weft yarns includes alternating larger diameter filler wefts and smaller diameter critical picks.
4. The industrial textile of claim 3, wherein the warp yarns of the first system of warp yarns only weave under the critical picks, and the warp yarns of the second system of warp yarns only weave over the critical picks.
5. The industrial textile of claim 1, wherein the repeating pattern of the warp yarns of the first system of warp yarns of under 1 of the weft yarns, over 1 of the weft yarns, and under 1 of the weft yarns forms a locking weave for maintaining a position of the warp warns of the first system of warp yarns, and the repeating pattern of the warp yarns of the second system of warp yarns of over 1 of the weft yarns, under 1 of the weft yarns, and over 1 of the weft yarns forms a locking weave for maintaining a position of the warp warns of the second system of warp yarns.
6. The industrial textile of claim 1, wherein the stacked pairs of the warp yarns are spaced apart to form an open mesh pattern.
7. The industrial textile of claim 6, wherein the stacked pairs of the warp yarns are spaced apart by at least 40% of a cross-direction dimension of one of the warp yarns.
8. The industrial textile of claim 1, wherein the floats on the first surface are arranged with a diagonal twill.
9. The industrial textile of claim 1, wherein the first system of warp yarns is made from a different material than the second system of warp yarns.
10. The industrial textile of claim 1, wherein the warp yarns of the first and second systems of warp yarns have a rectangular cross-section.
11. The industrial textile of claim 10, wherein the cross-section of the warp yarns of the first and second systems of warp yarns are the same.
12. The industrial textile of claim 10, wherein the weft yarns have a circular cross-section.
13. The industrial textile of claim 12, wherein the system of weft yarns includes alternating larger filler wefts having a diameter D1 and smaller critical picks having a diameter D2, the warp yarns of the first and second systems of warp yarns with the rectangular cross-section have a thickness t, wherein D1>D2, and (D1D2)/2t.
14. The industrial textile of claim 1, wherein the first system of warp yarns and second systems of warp yarns each have at least 100% warp fill.
15. The industrial textile of claim 1, wherein the first and second systems of warp yarns are woven with 8 sheds in 10 steps.
16. The industrial textile of claim 1, wherein the industrial textile is a papermaking fabric.
17. The industrial textile of claim 1, wherein the industrial textile is a dryer fabric for a papermaking fabric.
18. An industrial textile having first and second surfaces, the textile comprising: first and second systems of warp yarns interwoven with a system of weft yarns in a repeating pattern in which: adjacent pairs of the warp yarns in the first system of warp yarns are interwoven along a same path with the system of weft yarns on the first surface over at least 5 of the weft yarns and under 1 of the weft yarns in the repeating pattern forming adjacent pairs of floats on the first surface over the at least 5 of the weft yarns, adjacent pairs of the warp yarns in the second system of warp yarns are interwoven along a same path with the system of weft yarns on the second surface under at least 5 of the weft yarns and over 1 of the weft yarns in the repeating pattern forming adjacent pairs of floats on the second surface under the at least 5 of the weft yarns, and the adjacent pairs of warp yarns of the first system of warp yarns are stacked over corresponding ones of the adjacent pairs of warp yarns of the second system of warp yarns to form stacked, adjacent pairs of the warp yarns.
19. The industrial textile of claim 18, wherein the system of weft yarns includes alternating larger diameter filler wefts and smaller diameter critical picks.
20. The industrial textile of claim 19, wherein the warp yarns of the first system of warp yarns only weave under the critical picks, and the warp yarns of the second system of warp yarns only weave over the critical picks.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The foregoing Summary and the following detailed description will be better understood when read in conjunction with the appended drawings, which illustrate a preferred embodiment of the invention. In the drawings:
[0020]
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
[0028]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Certain terminology is used in the following description for convenience only and is not limiting. The fabric according to the invention is an industrial textile, which can have many industrial applications, such as conveyor belts, filtration fabrics, specialty fabrics for non-woven applications, etc. The words paper side (PS) and machine side (MS) designate surfaces of the fabric with reference to their use in one preferred application in a papermaking machine; however, these terms merely represent first and second or upper and lower surfaces of the planar fabric. Yarn is used to generically identify a monofilament or multifilament fiber. Warp and weft are used to designate yarns or monofilaments based on their position in the loom that extend in perpendicular directions in the fabric and either could be a machine direction (MD) or cross-machine direction (CMD) yarn in the fabric once it is installed on a papermaking machine, depending on whether the fabric is flat woven or continuously woven. In the preferred arrangement, the fabric is flat woven and seamed at the warp ends in order to form a continuous belt, so that the warp yarns are MD yarns and the weft yarns are CMD yarns.
[0030] One preferred application of the fabrics according to the invention is on a papermaking machine, and the fabric could have application as a base for a press fabric, or a dryer fabric for use in the corresponding press and dryer sections of a papermaking machine. These are generally all referred to as a papermaking fabric regardless of the position of use in a papermaking machine. Other applications include filtration fabrics, as well as other non-woven applications.
[0031] Referring to
[0032] The industrial textile 20 is woven with first and second systems of warp yarns 21, 22, which are interwoven with a system of weft yarns 30 in a repeating pattern. The warp yarns are identified as warp yarns 1-16, with the first group of warp yarns including the even numbered warp yarns, i.e., 2, 4, 6, 8, 10, 12, 14, 16, and the second system of warp yarns including the odd numbered warp yarns, i.e. 1, 3, 5, 7, 9, 11, 13, 15. The weft yarns 31-40 are interwoven with the warp yarns 1-16, of which preferably there are alternating larger diameter filler wefts 31, 33, 35, 37, 39, and a smaller diameter critical picks 32, 34, 36, 38, 40. Each of the warp yarns 2, 4, 6, 8, 10, 12, 14, 16 in the first system of warp yarns 21 is interwoven with the system of weft yarns 30 with a float on the first surface 24 over at least five of the weft yarns 31-40. In the first embodiment of the industrial textile 20, the floats of each of the warp yarns 2, 4, 6, 8, 10, 12, 14, 16 in the first system of warp yarns 21 are over 7 of the weft yarns 31-40. This is shown in connection with the warp yarn 2 in
[0033] Each of the warp yarns 1, 3, 5, 7, 9, 11, 13, 15 in the second system of warp yarns 22 is interwoven with the system of weft yarns 30 with a float on the second surface 26 under at least five of the weft yarns 31-40. In the first embodiment 20, preferably the warp yarns 1, 3, 5, 7, 9, 11, 13, 15 in the second system of warp yarns 22 are interwoven with the system of weft yarns 30 with a float on the second surface under 7 of the weft yarns 31-40. In order to form the locking weave, the warp yarns 1, 3, 5, 7, 9, 11, 13, 15 in the second system of warp yarns 22 then weave over one of the weft yarns 32, 34, 36, 38, 40 under one of the weft yarns 31, 33, 35, 37, 39, and over one of the weft yarns, 32, 34, 36, 38, 40 in the repeating pattern. As shown, each of the warp yarns 2, 4, 6, 8, 10, 12, 14, 16 of the first system of warp yarns 21 is stacked over a corresponding one of the warp yarns 1, 3, 5, 7, 9, 11, 13, 15 of the second system of warp yarns 22 to form stacked pairs of warp yarns. As illustrated in
[0034] In a preferred arrangement of the industrial textile 20, 100% warp fill is provided for each of the first and second systems of warp yarns 21, 22, which, in combination with the locking weaves, provide an extremely stable fabric 20.
[0035] In a preferred arrangement, the warp yarns 1-16 preferably have a rectangular cross-sectional shape which contributes to the stability of the fabric 20 and its smoothness. The warp yarns 1-16 are preferably monofilaments formed of a polymeric material. In one embodiment, the dimensions are 0.251.05 mm or 0.361.07 mm to obtain a width to height ratio of between 4:1 and 3:1. Those skilled in the art will recognize that other cross-sectional shapes and ratios may also be used, such as oval or flattened shapes with rounded sides and aspect ratios of 2:1 to 6:1. The weft yarns 31-40 preferably have a circular cross-sectional shape that in some preferred arrangements may range in size from 0.6 mm, 0.7 mm, 0.8 mm, or 0.9 mm. Other sizes may also be used depending on the intended application for the fabric. In one preferred arrangement, the fabric 20 is woven at 22 picks per inch (weft yarns per inch) (8.7 yarns/cm).
[0036] The use of first and second systems of warp yarns, 21, 22 also allow different materials to be used for the first and second system of warp yarns 21, 22 in order to provide optimal materials on the first and second surfaces 24, 26, of the industrial textile 20 for the preferred application.
[0037] For example, the monofilament warp yarns 2, 4, 6, 8, 10, 12, 14, 16 of the first system of warp yarns 21 used to form the first surface 24 can be comprised of PPS (polyphenylene sulfide) or PCTA (polycylcohexane dimethanol terephthalic acid) polymers which are more resistant to thermal and hydrolytic degradation than PET (polyethylene terephthalate) yarns (and more expensive). The warp yarns 1, 3, 5, 7, 9, 11, 13, 15 of the second system of warp yarns can be formed from PET polymer since the PS of the textile (at least in papermaking applications) is where heat and hydrolysis resistance are less critical yarn properties. Those skilled in the art will understand from the present disclosure that these materials are merely exemplary, and that other materials could be used depending on the particular application. These warp yarns 1-16 may be grooved, profiled, coated, or otherwise treated for contamination resistance.
[0038] Additionally, due to the long warp floats, a higher contact area can be achieved that reduces fabric wear rates in comparison to similar fabrics having more defined knuckles due to the weave. The long warp floats also provide for benefits in contamination resistance in comparison to similar weft proud fabrics.
[0039] Preferably, industrial textile 20 is formed into a continuous loop for use as a papermaking fabric, and more particularly as a papermaking dryer fabric, for use on a papermaking machine. In order to form the loop, a seam is created at the ends of the warp yarns 1-16. Preferably, the seam uses 100% of the warp yarns to form the seam. Seams can be formed in a known manner by unweaving and back-weaving warp yarns from the first system of warp yarns 21 back into the fabric along the paths of the corresponding stacked ones of the warp yarns from the second system of warp yarns 22 that have been cut back from the end of the fabric to form seam loops at each end of the planar fabric, with the seam loops then being interdigitated and joined by a pintle to form an endless fabric loop. Other types of seaming, such as QuickLink seam, which was developed by AstenJohnson, the assignee of the present invention, can also be utilized. In a preferred arrangement for papermaking, the warp fill is preferably about 200% warp fill, with each layer having warp yarns woven at about 100% warp fill. This contributes to the stability of the industrial textile 20 and helps to resist creasing and distortion due to the fact that the warp yarns 1-16 in each layer are woven at about 100% warp fill, and thus are immediately adjacent to and braced against one another. This in connection with the locking weave provides enhanced fabric stability for the industrial textile 20.
[0040] Referring to
[0041] Referring now to
[0042] Preferably the industrial textiles 120, 120 are formed into endless belts by seaming at the warp ends as discussed above in connection with the first embodiment of the industrial textile 20. A preferred application for the industrial textile 120 is as a papermaking fabric, and in particular, a dryer fabric for a papermaking machine.
[0043] A preferred application for the industrial textile 120 is for use as a dryer fabric. However, those skilled in the art will recognize that there are other applications.
[0044] Referring to
[0045]
[0046] In order to provide for smooth first and second surfaces 24, 26, of the fabric 20, as well as the first and second surfaces 124, 126; 124, 126; 224, 226; 324, 326 of the industrial textiles 120, 120, 220, 320 preferably, the filler wefts 31, 33, 35, 37, 39; 131, 133, 135, 137; 131, 133, 135, 137; 231, 233, 235, 237, 239, 241; 331, 333, 335, 337 have a diameter D1 and the smaller critical pics 32, 34, 36, 38, 40; 132, 134, 136, 138; 132, 134, 136, 138; 232, 234, 236, 238, 240, 242; 332, 334, 446, 338 have a diameter D2 which is smaller than D1, and the warp yarns 1-16, 101-104, 101-104, 210-216, 301-316 have a rectangular cross-section with a thickness t. Preferably, (D1D2)/22t. This provides for generally smooth first and second surfaces in the industrial textiles 20, 120, 120, 220, 320. In one exemplary embodiment D1=0.90 mm, D2=0.60 mm and t=1.55 mm. Those skilled in the art will recognize that other dimensions could be used depending on the particular application.
[0047] Having thus described the present invention in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the invention, could be made without altering the inventive concepts and principles embodied therein. It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. The present embodiment and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein.