Papermaking fabric with double loop seam

Abstract

A seam for joining together the ends of woven fabric to form an endless belt is particularly suitable for joining the ends of woven synthetic dryer fabrics as used in the dryer section of paper making machines and is particularly applicable to joining the ends of those dryer fabrics in at least the machine direction of the fabric. A papermaking fabric comprising a woven fabric body having opposing ends, said fabric body having a system of MD-yarns interwoven with a system of CD yarns. The MD-yarns include first pairs of MD-yarns, second pairs of MD-yarns and third pairs of MD-yarns and the first and the second pairs of MD-yarns form two seam loops, while the third MD-yarns forms the binder. The loops are at identical length to each other over the whole fabric width. Such seam construction reduces marking and increases the seam strength and seam abrasion resistance.

Claims

1. A papermaking fabric, comprising: a woven fabric body having opposing ends defining widthwise edges; said fabric body having a system of MD-yarns interwoven with a system of CD yarns in a single layer weave construction; said MD-yarns including first pairs of MD-yarns, second pairs of MD-yarns, and third pairs of MD-yarns; said first pairs, second pairs, and third pairs of MD-yarns being interwoven with said CD yarns in a repeat weave pattern; and each of said first and second pairs of MD-yarns forming seaming loops at at least one of said widthwise edges of said fabric, said loops having an identical length to each other over an entire fabric width.

2. The papermaking fabric according to claim 1, wherein the said first pairs, second pairs and third pairs of MD-yarns are arranged in sequence, said second pairs of MD-yarns are adjacent said first pairs of MD-yarns, and said third pairs of MD-yarns are adjacent said second pairs of MD-yarns.

3. The papermaking fabric according to claim 1, wherein: the first pairs of MD-yarns include said first MD-yarns folded back and second MD-yarns in alignment and substantial abutment with said first MD-yarns to form a first group of loops; the second pairs of MD-yarns include third MD-yarns folded back and fourth MD-yarns in alignment and substantial abutment with said third MD-yarns to form a second group of loops; the third pairs of MD-yarns include fifth MD-yarns folded back and sixth MD-yarns in alignment and substantial abutment with said fifth MD-yarns holding the last CD-yarns forming the end of the fabric.

4. The papermaking fabric according to claim 1, wherein said loops are formed at each end of said fabric body and cooperate with corresponding loops located at an adjacent opposed end of an adjacent fabric body to receive a retaining member and thereby form a seam and making the fabric endless.

5. The papermaking fabric according to claim 1, wherein said MD-yarns are of a polymeric material.

6. The papermaking fabric according to claim 5, wherein said polymeric material is selected from the group consisting of PET, PCTA, PPS, each alone or in combination.

7. The papermaking fabric according to claim 1, wherein the said warp yarns have a rectangular cross section.

8. The papermaking fabric according to claim 7, wherein said MD-yarns have a size dimension within a range of between 0.25 mm0.55 mm and 0.45 mm0.75 mm.

9. The papermaking fabric according to claim 8, wherein a size of said MD-yarns is 0.360.67 mm.

10. The papermaking fabric according to claim 1, wherein said warp yarns have a round cross section.

11. The papermaking fabric according to claim 10, wherein said round MD-yarns have diameter of between 0.50 mm and 0.70 mm.

12. The papermaking fabric according to claim 11, wherein the diameter of said round MD-yarns is 0.60 mm.

13. A papermaking fabric, comprising: a woven fabric body having opposing ends, said fabric body having a system of MD-yarns interwoven with a system of CD yarns; said fabric having a single layer weave construction; and a seam with seam loops, said loops having an identical length to each other over an entire fabric width, and wherein a percentage of MD-yarn ends formed as the seam loops is 33.3%.

14. The papermaking fabric according to claim 13, wherein said MD-yarns are made of a polymeric material.

15. The papermaking fabric according to claim 14, wherein said polymeric material is selected from the group consisting of PET, PCTA, PPS, each alone or in combination.

16. The papermaking fabric according to claim 13, wherein the said warp yarns having a rectangular cross section.

17. The papermaking fabric according to claim 16, wherein said MD-yarns have a size dimension within a range of between 0.25 mm0.55 mm and 0.45 mm0.75 mm.

18. The papermaking fabric according to claim 17, wherein a size of said MD-yarns is 0.360.67 mm.

19. The papermaking fabric according to claim 13, wherein said warp yarns have a round cross section.

20. The papermaking fabric according to claim 19, wherein said round MD-yarns have diameter of between 0.50 mm and 0.70 mm.

21. The papermaking fabric according to claim 20, wherein the diameter of said round MD-yarns is 0.60 mm.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a partial plan view of a fabric with a normal single loop seam; and

(2) FIG. 2 is a partial plan view of a fabric with a double loop seam

DESCRIPTION OF PREFERRED EMBODIMENTS

(3) Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a partial plan view of a fabric with a normal single loop seam. The papermaking fabric comprises a woven fabric body having opposing ends. The fabric body has a system of MD-yarns interwoven with a system of CD yarns. The fabric has a single layer weave construction. The MD-yarns comprise first pairs of MD-yarns and second pairs of MD-yarns. The first pairs of MD-yarns including first MD-yarns folded back and second MD-yarns in alignment and substantial abutment with said first MD-yarns to form first loops. Such existing small loop seams (loop made from the warp yarn) contain only one seam loop and one binder. There is only one loop used as the fabric end connector of every four ends. The seam strength and abrasion resistance are limited. Such design contains four ends per repeat of its weave pattern. Two MD-yarn ends are used to form a loop and the other two are for the binder. The MD-yarn ends used for the seam loops is 25%.

(4) FIG. 2 shows a partial plan view of a fabric with a double loop seam according to an embodiment of the present invention. The papermaking fabric comprises a woven fabric body having opposing ends. The fabric body has a system of MD-yarns interwoven with a system of CD yarns. The fabric has a single layer weave construction. The MD-yarns include first pairs of MD-yarns, second pairs of MD-yarns and third pairs of MD-yarns. The first pairs, second pairs and third pairs MD-yarns are interwoven with the CD yarns in a repeat weave pattern. Each of the first and second pairs form seaming loops at widthwise edges of the fabric. The first pairs, second pairs and third pairs MD-yarns are arranged in the sequence, the said second pairs of MD-yarns are adjacent to the said first pairs of MD-yarns, and the said third pairs of MD-yarns are adjacent to the said second pairs of MD-yarns. The first pairs of MD-yarns including first MD-yarns1 folded back and second MD-yarns2 in alignment and substantial abutment with said first MD-yarns to form first groups of loops; the second pairs of MD-yarns including third MD-yarns3 folded back and fourth MD-yarns4 in alignment and substantial abutment with said third MD-yarns to form a second group of loops; the third pairs of MD-yarns including fifth MD-yarns5 folded back and sixth MD-yarns6 in alignment and substantial abutment with said fifth MD-yarns5; holding the last CD-yarns forming the end of the fabric. The said loops being located at each end of the fabric body and cooperating with corresponding loops located at an adjacent opposed end of an adjacent fabric body to receive a retaining member and thereby form a seam which makes the fabric endless. And wherein the said loops are at identical length to each other over the whole fabric width.

Embodiment 1

(5) A papermaking fabric comprising a woven fabric body having opposing ends, said fabric body having a system of MD-yarns interwoven with a system of CD yarns; wherein the fabric has a single layer weave construction; wherein the said MD-yarns comprising first pairs of MD-yarns, second pairs of MD-yarns and third pairs of MD-yarns; wherein said first pairs, second pairs and third pairs MD-yarns are interwoven with said CD yarns in a repeat weave pattern; wherein each of said first and second pairs form seaming loops at widthwise edges of said fabric. The said first pairs, second pairs and third pairs MD-yarns are arranged in a sequence, such that the said second pairs of MD-yarns are adjacent to the said first pairs of MD-yarns, and the said third pairs of MD-yarns are adjacent to the said second pairs of MD-yarns. The first pairs of MD-yarns including first MD-yarns1 folded back and second MD-yarns2 in alignment and substantial abutment with said first MD-yarns to form a first group of loops; the second pairs of MD-yarns including third MD-yarns3 that are folded back, and fourth MD-yarns4 in alignment and substantial abutment with said third MD-yarns to form a second group of loops; the third pairs of MD-yarns including fifth MD-yarns5 folded back and sixth MD-yarns6 in alignment and substantial abutment with said fifth MD-yarns5; holding the last CD-yarns forming the end of the fabric. The said loops being located at each end of the fabric body and cooperating with corresponding loops located at an adjacent opposed end of an adjacent fabric body to receive a retaining member and thereby form a seam which makes the fabric endless. And wherein the said loops are at identical length to each other over the whole fabric width. The MD-yarns are made of PET. The said wrap yarns having a rectangular cross section and the size of the said MD-yarns is 0.25 mm0.55 mm.

Embodiment 2

(6) A papermaking fabric comprising a woven fabric body having opposing ends, said fabric body having a system of MD-yarns interwoven with a system of CD yarns; wherein the fabric has a single layer weave construction; wherein the said MD-yarns comprising first pairs of MD-yarns, second pairs of MD-yarns and third pairs of MD-yarns; wherein said first pairs, second pairs and third pairs MD-yarns are interwoven with said CD yarns in a repeat weave pattern; wherein each of said first and second pairs form seaming loops at widthwise edges of said fabric. The said first pairs, second pairs and third pairs MD-yarns are arranged in a sequence, such that the said second pairs of MD-yarns are adjacent to the said first pairs of MD-yarns, and the said third pairs of MD-yarns are adjacent to the said second pairs of MD-yarns. The first pairs of MD-yarns including first MD-yarns1 folded back and second MD-yarns2 in alignment and substantial abutment with said first MD-yarns to form a first group of loops; the second pairs of MD-yarns including third MD-yarns3 folded back and fourth MD-yarns4 in alignment and substantial abutment with said third MD-yarns to form a second group of loops; the third pairs of MD-yarns including fifth MD-yarns5 folded back and sixth MD-yarns6 in alignment and substantial abutment with said fifth MD-yarns5; holding the last CD-yarns forming the end of the fabric. The said loops being located at each end of the fabric body and cooperating with corresponding loops located at an adjacent opposed end of an adjacent fabric body to receive a retaining member and thereby form a seam which makes the fabric endless. And wherein the said loops are at identical length to each other over the whole fabric width. The MD-yarns are made of PCTA. The said wrap yarns having a rectangular cross section and the size of the said MD-yarns is 0.45 mm0.75 mm.

Embodiment 3

(7) A papermaking fabric comprising a woven fabric body having opposing ends, said fabric body having a system of MD-yarns interwoven with a system of CD yarns; wherein the fabric has a single layer weave construction; wherein the said MD-yarns comprising first pairs of MD-yarns, second pairs of MD-yarns and third pairs of MD-yarns; wherein said first pairs, second pairs and third pairs MD-yarns are interwoven with said CD yarns in a repeat weave pattern; wherein each of said first and second pairs form seaming loops at widthwise edges of said fabric. The said first pairs, second pairs and third pairs MD-yarns are arranged in a sequence, such that the said second pairs of MD-yarns are adjacent to the said first pairs of MD-yarns, and the said third pairs of MD-yarns are adjacent to the said second pairs of MD-yarns. The first pairs of MD-yarns including first MD-yarns1 folded back and second MD-yarns2 in alignment and substantial abutment with said first MD-yarns to form a first group of loops; the second pairs of MD-yarns including third MD-yarns3 that are folded back, and fourth MD-yarns4 in alignment and substantial abutment with said third MD-yarns to form a second group of loops; the third pairs of MD-yarns including fifth MD-yarns5 folded back and sixth MD-yarns6 in alignment and substantial abutment with said fifth MD-yarns5; holding the last CD-yarns forming the end of the fabric. The said loops being located at each end of the fabric body and cooperating with corresponding loops located at an adjacent opposed end of an adjacent fabric body to receive a retaining member and thereby form a seam which makes the fabric endless. And wherein the said loops are at identical length to each other over the whole fabric width. The MD-yarns are made of PPS. The said wrap yarns having a rectangular cross section and the size of the said MD-yarns is 0.360.67 mm.

Embodiment 4

(8) A papermaking fabric comprising a woven fabric body having opposing ends, said fabric body having a system of MD-yarns interwoven with a system of CD yarns; wherein the fabric has a single layer weave construction; wherein the said MD-yarns comprising first pairs of MD-yarns, second pairs of MD-yarns and third pairs of MD-yarns; wherein said first pairs, second pairs and third pairs MD-yarns are interwoven with said CD yarns in a repeat weave pattern; wherein each of said first and second pairs form seaming loops at widthwise edges of said fabric. The said first pairs, second pairs and third pairs MD-yarns are arranged in a sequence, such that the said second pairs of MD-yarns are adjacent to the said first pairs of MD-yarns, and the said third pairs of MD-yarns are adjacent to the said second pairs of MD-yarns. The first pairs of MD-yarns including first MD-yarns1 folded back and second MD-yarns2 in alignment and substantial abutment with said first MD-yarns to form a first group of loops; the second pairs of MD-yarns including third MD-yarns3 that are folded back, and fourth MD-yarns4 in alignment and substantial abutment with said third MD-yarns to form a second group of loops; the third pairs of MD-yarns including fifth MD-yarns5 folded back and sixth MD-yarns6 in alignment and substantial abutment with said fifth MD-yarns5; holding the last CD-yarns forming the end of the fabric. The said loops being located at each end of the fabric body and cooperating with corresponding loops located at an adjacent opposed end of an adjacent fabric body to receive a retaining member and thereby form a seam which makes the fabric endless. And wherein the said loops are at identical length to each other over the whole fabric width. The MD-yarns are made of 30% PPS and 70% PCTA. The said wrap yarns having a round cross section and the dimension of the said round MD-yarns is 0.50 mm.

Embodiment 5

(9) A papermaking fabric comprising a woven fabric body having opposing ends, said fabric body having a system of MD-yarns interwoven with a system of CD yarns; wherein the fabric has a single layer weave construction; wherein the said MD-yarns comprising first pairs of MD-yarns, second pairs of MD-yarns and third pairs of MD-yarns; wherein said first pairs, second pairs and third pairs MD-yarns are interwoven with said CD yarns in a repeat weave pattern; wherein each of said first and second pairs form seaming loops at widthwise edges of said fabric. The said first pairs, second pairs and third pairs MD-yarns are arranged in a sequence, such that the said second pairs of MD-yarns are adjacent to the said first pairs of MD-yarns, and the said third pairs of MD-yarns are adjacent to the said second pairs of MD-yarns. The first pairs of MD-yarns including first MD-yarns1 folded back and second MD-yarns2 in alignment and substantial abutment with said first MD-yarns to form a first group of loops; the second pairs of MD-yarns including third MD-yarns3 that are folded back, and fourth MD-yarns4 in alignment and substantial abutment with said third MD-yarns to form a second group of loops; the third pairs of MD-yarns including fifth MD-yarns5 folded back and sixth MD-yarns6 in alignment and substantial abutment with said fifth MD-yarns5; holding the last CD-yarns forming the end of the fabric. The said loops being located at each end of the fabric body and cooperating with corresponding loops located at an adjacent opposed end of an adjacent fabric body to receive a retaining member and thereby form a seam which makes the fabric endless. And wherein the said loops are at identical length to each other over the whole fabric width. The MD-yarns are made of 40% PET and 60% PPS. The said wrap yarns having a round cross section and the dimension of the said round MD-yarns is 0.70 mm.

Embodiment 6

(10) A papermaking fabric comprising a woven fabric body having opposing ends, said fabric body having a system of MD-yarns interwoven with a system of CD yarns; wherein the fabric has a single layer weave construction; wherein the said MD-yarns comprising first pairs of MD-yarns, second pairs of MD-yarns and third pairs of MD-yarns; wherein said first pairs, second pairs and third pairs MD-yarns are interwoven with said CD yarns in a repeat weave pattern; wherein each of said first and second pairs form seaming loops at widthwise edges of said fabric. The said first pairs, second pairs and third pairs MD-yarns are arranged in a sequence, such that the said second pairs of MD-yarns are adjacent to the said first pairs of MD-yarns, and the said third pairs of MD-yarns are adjacent to the said second pairs of MD-yarns. The first pairs of MD-yarns including first MD-yarns1 folded back and second MD-yarns2 in alignment and substantial abutment with said first MD-yarns to form a first group of loops; the second pairs of MD-yarns including third MD-yarns3 folded back and fourth MD-yarns4 in alignment and substantial abutment with said third MD-yarns to form a second group of loops; the third pairs of MD-yarns including fifth MD-yarns5 folded back and sixth MD-yarns6 in alignment and substantial abutment with said fifth MD-yarns5; holding the last CD-yarns forming the end of the fabric. The said loops being located at each end of the fabric body and cooperating with corresponding loops located at an adjacent opposed end of an adjacent fabric body to receive a retaining member and thereby form a seam which makes the fabric endless. And wherein the said loops are at identical length to each other over the whole fabric width. The MD-yarns are made of 70% PPS and 30% PCTA. The said wrap yarns having a round cross section and the dimension of the said round MD-yarns is 0.60 mm.

(11) Based on the above explanation, the various features of the other embodiments of this invention would be readily understood by a person skilled in the art. Therefore, no further explanation is provided herein.

(12) It also should be noted that the yarn diameters of the paper side MD-yarns and the wear side MD-yarns can be varied, and preferably are different from each other. The most preferred relationships of the diameters of the paper side MD-yarns and the wear side MD-yarns is disclosed in the Summary of the Invention and will not be repeated herein for purposes of brevity. Suffice it to state that the specified yarn diameters and their disclosed relationship to each other can be employed in all of the various disclosed embodiments of this invention.

(13) Finally, although reference has been made to the yarns of the various disclosed embodiments having diameters, it is to be understood that the cross sectional shape of any or all of the yarns used in any of the embodiments may be of non-circular profile e.g., ovate, rectangular, square, bi-nodal, etc.