JP2023070320A - Seam felt base fabric for paper making - Google Patents

Abstract

To provide a seam felt for paper making in which a portion of the warp yarn folded to form a loop is difficult to be pulled out from the fabric part.SOLUTION: A seam felt base fabric 2 for paper making of the invention is provided with weft yarn 6 including upper weft yarn 8 and lower weft yarn 9, and warp yarn 7 into which the weft yarn 6 is interwoven. The seam felt base fabric 2 for paper making is also provided with a loop section 5 including a loop 4 and a fabric part 10 in which the warp yarn 7 is interwoven with the weft yarn 6. The loop 4 is formed by folding the warp yarn 7, and a folded portion 13 is woven into the fabric part 10. The folded portion 13 forms a larger structure of crimps than the portion positioned in the center of the warp direction above a mating point 14. The larger crimped structure prevents the folded portion 13 from coming out in the warp yarn 7.SELECTED DRAWING: Figure 2

Description

The present invention relates to a papermaking seam felt substrate.

Papermaking seam felts are used in press parts of paper machines, pulp machines, etc., to convey wet paper that is to be squeezed. Seam felt for papermaking has wet paper transportability, water squeezing, surface property that does not leave marks on the paper surface (paper surface property), initial familiarity related to the time from being attached to a paper machine etc. to a favorable state, Antifouling property, durability, etc. are required. When the seam felt for papermaking is attached to a paper machine or the like, the loops provided at both ends of the seam felt are interlocked with each other, and the core wire is inserted through the loops and joined to make the seam felt endless.

As one of the methods for forming loops in a seam felt base fabric for papermaking, after weaving the base fabric in a flat plate shape (having ends in the warp direction), the warp yarns are folded back to form a loop, and the folded back portion is formed. is known as a method of weaving into the base (for example, Patent Document 1). A loop of a dryer canvas used in the dryer part of a paper machine may also be formed by a similar method (for example, Patent Documents 2 and 3).

In the invention described in Patent Document 1, the joints between the portion folded back to form the loop and other warp yarns are scattered, including the overlapping portion (aligning portion) and the butting portion where both yarns overlap each other. . In the invention described in Patent Document 2, both yarns overlap by the length of two weft yarns at the seams (thread-lifting cut points), and these are dispersed. In the invention described in Patent Document 3, the seam is formed by butting both yarns, and two seams adjacent in the weft direction are arranged to be shifted in the warp direction.

JP-A-4-73288 JP-A-8-302585 U.S. Pat. No. 7,624,767

The base fabric thus formed has a problem in that the portion of the warp that is folded back to form the loop tends to come off from the base.

In view of the above background, it is an object of the present invention to provide a papermaking seam felt in which the looped portions of the warp yarns are less likely to come off from the ground portion.

In order to solve the above problems, one aspect of the present invention is to provide an upper weft (8) extending in the weft direction, and a lower weft arranged on the running surface side of the upper weft (8) and extending in the weft direction. A seam felt base fabric (2, 21) for papermaking, comprising a weft (6) containing (9) and a warp (7) extending in the warp direction and woven with the weft (6), a base portion (10, 22) in which the weft (6) weaves the warp (7); and a loop portion (5) projecting from both ends of the base portion (10, 22) in the warp direction, the loop The part (5) includes a plurality of loops (4) formed by folding back the warp (7), and two warp rows connected by the loop (4) near the ends in the warp direction. in a pair of warp yarns (7) arranged to form a pair of warp yarns (7), one of the pair of warp yarns (7) is folded back to form the loop (4), and the one folded portion (13 , 23) and the other ends of the pair of warp yarns (7) are arranged so as to overlap or face each other in the ground portions (10, 22) when viewed from the weft direction. By doing so, a seam (14) is formed, and in the pair of warps (7), at least a part of the one of the folded portions (13, 23) is more likely than the seam (14). also forms a larger crimp structure than the longitudinally centrally located portion.

According to this aspect, at least a portion of the folded portion forms a larger crimped structure than the portion arranged in the center in the warp direction from the seam, thereby hardly changing the paper surface property. It is possible to prevent the folded portion from slipping out of the base.

In the papermaking seam felt base fabric (2) of the above aspect, the ground portion (10) includes an end ground portion (11) arranged adjacent to each of the loop portions (5), and the two and a main ground portion (12) disposed between the end ground portions (11), wherein the seam (14) is formed in the main ground portions (12) and the end ground portions (11) The warp yarns (7) in may form a structure having a larger crimp than the warp yarns (7) in the main fabric portion (12).

According to this aspect, the warp forming the loop is firmly held on both sides by the wefts of the end ground portion, so that the effect of suppressing the warp from coming off is enhanced.

In the papermaking seam felt base fabric (2) of the above aspect, the length between the wefts (6) arranged at both ends in the warp direction of the end base (11) is 5 to 7 cm. Also good.

The main fabric portion is superior in paper surface property to the end portion fabric portion, and the end portion fabric portion has stronger resistance to warp shedding than the main fabric portion. The balance with suppression of deterioration is improved.

In the papermaking seam felt base fabric (21) of the above aspect, in the base portion (22), the portion of the folded portion (23) excluding the seam (14) is a pair of A larger crimp structure may be formed than other portions of the warp yarns (7).

According to this aspect, since the resistance against coming off is increased only in the folded portion where coming off is likely to occur, the coming off of the warp is suppressed and the deterioration of the paper surface property is suppressed.

In the papermaking seam felt base fabric (2, 21) of the above aspect, the wefts (6) may be arranged at 13.8 to 17.7 per cm in the warp direction.

According to this aspect, the balance between water squeezing, paper surface property and durability is improved.

In the papermaking seam felt base fabric (2, 21) of the above aspect, the seam (14) is formed between the end of the one folded portion (13, 23) and the other end of the folded portion (13, 23). may be formed by overlapping 5 to 13 weft yarns when viewed in the weft direction.

According to this aspect, a frictional force acts between the warp yarns that overlap each other, and the separation of the portion of the warp yarns forming the seams from the weft yarns is suppressed.

In the papermaking seam felt base fabric (2, 21) of the above aspect, in the vicinity of each end in the warp direction, the seam (14) is formed by 250 wefts ( They may be arranged at a distance of 6) or more.

According to this aspect, the joint is arranged at a distance of 250 wefts or more from the loop portion, so that the folded back portion is woven into the weft with a length of a predetermined value or more, This enhances the effect of suppressing warp shedding.

In the papermaking seam felt base fabrics (2, 21) of the above aspect, the seams (14) adjacent to each other in the weft direction near each end in the warp direction have They may be arranged so as to be separated from each other by a distance of 17 wefts (6) or more in the warp direction.

According to this aspect, since the seams where the warp yarns are densely arranged are dispersed, the deterioration of paper surface property and water squeezability is suppressed.

In the papermaking seam felt base fabric (2, 21) of the above aspect, the ratio between the number of upper wefts (8) and the number of lower wefts (9) is 1:1, and the upper wefts (8 ) and the lower weft (9) may be alternately arranged at positions offset from each other in the warp direction.

According to this aspect, compared with the case where the upper weft and the lower weft are aligned in the thickness direction, the thickness change in the thickness direction is smaller, so the stretchability in the warp direction is lower, and the dimensional stability is improved. is superior.

According to the above aspect, it is possible to provide a papermaking seam felt in which the portion of the warp that is folded back to form the loop is difficult to come off from the base portion.

1 is a perspective view of a papermaking seam felt according to a first embodiment; FIG. A plan view of the seam felt base fabric for papermaking according to the first embodiment (A: loop portion and edge base portion, B: main base portion including seams) Sectional view of a surface parallel to the warp direction and the thickness direction of the papermaking seam felt base fabric according to the first embodiment Sectional view of a surface parallel to the warp direction and thickness direction of the papermaking seam felt base fabric according to the first embodiment (main base portion including seams) Explanatory drawing of crimp size (A: Comparative example, B: Edge portion, C: Main portion) Loop portions viewed from the warp direction in seam felt base fabrics for papermaking according to Comparative Example and First Embodiment (A: Comparative Example, B: First Embodiment) Cross-sectional view of a plane parallel to the warp direction and the vertical direction of the seam felt base fabric for papermaking according to the first embodiment and its modification (A: modification, B: edge base, C: main base) Plan view of the seam felt base fabric for papermaking according to the second embodiment (A: near the edge, B: base including the seam) Sectional view of a surface parallel to the warp direction and thickness direction of the papermaking seam felt base fabric according to the second embodiment Cross-sectional view of a plane parallel to the warp direction and thickness direction of the papermaking seam felt base fabric according to the second embodiment (ground portion including seams)

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 7 show a first embodiment.

FIG. 1 is a perspective view of a papermaking seam felt 1. FIG. The papermaking seam felt 1 includes a papermaking seam felt base fabric 2 (hereinafter referred to as "base fabric 2") and a staple fiber sheet of a synthetic resin such as polyamide, polyester, polyethylene, polypropylene, polyvinyl chloride, etc. and a batt fiber layer 3 formed by needling. A loop portion 5 including a plurality of loops 4 is formed at an end portion of the base fabric 2 in the warp direction. The papermaking seam felt 1 is used in the press part of a paper machine, and is made endless by interlocking loops 4 provided at both ends and inserting and joining the core wire into the loops. The surface side) is supported by rolls (not shown) of a paper machine or the like, and the outer (paper-making side) surface supports the wet paper web.

As shown in FIG. 2, the base fabric 2 includes a plurality of weft yarns 6 extending in the weft direction and a plurality of warp yarns 7 extending in the warp direction and into which the weft yarns 6 are woven. The "warp direction" is the longitudinal direction of the base fabric 2, and coincides with the direction of travel (machine direction) of the paper machine when attached to the paper machine. The "weft direction" is the width direction of the backing 2 and coincides with the direction perpendicular to the machine direction (cross-machine direction) along the plane of the backing 2 when mounted on a paper machine. The weft yarns 6 are arranged in the warp direction at 13.8 to 17.7 threads per cm (35 to 45 threads per inch) ("x to y" means from x to y, the same shall apply hereinafter). The warp yarns 7 are arranged at 18.1-22.8 threads per cm (46-58 threads per inch) in the weft direction.

The wefts 6 include a plurality of upper wefts 8 arranged on the papermaking surface side and a plurality of lower wefts 9 arranged on the running surface side. The ratio of the number of upper weft yarns 8 to the number of lower weft yarns 9 is 1:1. They are alternately arranged at positions offset in the longitudinal direction. Each warp yarn 7 is woven into an upper weft yarn 8 and a lower weft yarn 9 . Such a woven fabric in which one layer of warp yarns 7 is woven into upper and lower two layers of weft yarns 6 is sometimes called a warp-single-weft-double-weave fabric.

The base fabric 2 includes a ground portion 10 in which the weft yarns 6 weave the warp yarns 7, and two loop portions 5 projecting from both ends of the ground portion 10 in the warp direction. The loop portion 5 includes the loop 4 formed by folding back the warp yarn 7 and does not include the weft yarn 6 . The ground portion 10 includes two end ground portions 11 arranged adjacent to each of the loop portions 5 and a main ground portion 12 arranged between the two end ground portions 11 . The complete weave of the end ground portion 11 is composed of three upper wefts 8 , three lower wefts 9 and three warps 7 . The complete weave of the main fabric portion 12 is composed of four upper wefts 8 , four lower wefts 9 and eight warps 7 . It should be noted that the weft yarn No. and warp no. , numbers with "'" (1', 2', . ) correspond to the weft 6 and the warp 7 of the main fabric portion 12 .

The loops 4 of the loop portion 5 are formed in the vicinity of the ends of the base fabric 2 so that the warp yarn No. 8, 2, 4 and 6 warp rows are formed by folding back the warp yarns 7, and the folded back portion 13 is woven into the ground portion 10 in a predetermined range from the loop 4, and the warp yarns No. It constitutes part of the 1, 3, 5 and 7 warp rows. Although not shown, a loop 4 is similarly formed at the opposite end.

Note that the loop 4 on the opposite side is warp No. 1, 3, 5, and 7 are formed by folding back the warp yarns 7, and the folded back portion 13 extends from the loop 4 to the warp yarn No. 1 in a predetermined range. 8, 2, 4 and 6 warp rows may be constructed. Also, the loop 4 on the opposite side is warp No. 8, 2, 4 and 6 warp rows are formed by folding back the warp yarns 7, and the folded back portion 13 extends from the loop 4 to the warp yarns No. 8 in a predetermined range. 7, 1, 3 and 5 warp rows may be constructed. Also, the loop 4 on the opposite side is warp No. 1, 3, 5, and 7 are formed by folding back the warp yarns 7, and the folded back portion 13 extends from the loop 4 to the warp yarn No. 1 in a predetermined range. 2, 4, 6 and 8 warp rows may be constructed.

Please refer to FIG. 2(A), FIG. 3 and FIG. 7(B). The length of the end base portion 11 in the warp direction, that is, the length between the weft yarns 6 arranged at both end portions in the warp direction of the end base portion 11 is 5 to 7 cm. For the convenience of illustration, only 12 wefts 6 are shown in the end ground portion 11 in FIGS. In the end base portion 11, the weft yarn No. 1′, 3′ and 5′ weft rows are composed of the lower weft yarn 9, and the weft yarn No. 2', 4' and 6' weft rows are constituted by upper weft yarns 8. FIG. Warp No. 1' warp yarn 7 is the weft yarn No. It passes under, under, above, above, above and below the wefts 6 of 1' to 6' in order. Warp No. 2' warp yarns 7 are warp yarns No. 1′, two wefts 6 (one upper weft 8 or lower weft 9) are added to the weft No. 1′. is woven into the weft yarn 6 while shifting to the smaller one. Warp No. 3' warp yarns 7 are warp yarns No. 1′, two wefts 6 are added to the wefts No. 1′. is woven into the weft yarn 6 while shifting to the larger one.

Please refer to FIG. 2(B), FIG. 4 and FIG. 7(C). In the main fabric portion 12, the weft yarn No. 1, 3, 5 and 7 weft rows are constituted by the upper weft 8, and weft No. 2, 4, 6 and 8 weft rows are constituted by the lower weft yarn 9 . Warp No. The warp yarns 7 of No. 1 are the weft yarns No. 1. The weft yarns 6 of 1 to 8 pass through in order below, below, below, above, above, above, below, above. Warp No. The warp yarns 7 of No. 2 are the warp yarns No. 1 warp yarn 7, two weft yarns 6 are added to the weft yarn No. is woven into the weft yarn 6 while shifting to the larger one. Warp No. The warp yarns 7 of No. 3 are the warp yarns No. 3. 1 warp yarn 7, two weft yarns 6 are added to the weft yarn No. is woven into the weft yarn 6 while shifting to the smaller one. Warp No. The warp yarns 7 of No. 4 are the warp yarns No. 4. It is woven into the weft yarns 6 with a shift of four weft yarns 6 with respect to one warp yarn 7.例文帳に追加

Warp No. The weaving pattern of the warp yarns 7 of No. 5 to No. The weaving pattern of the warp yarns 7 of 1 to 4 forms a mirror image symmetrical shape with respect to a predetermined cross section perpendicular to the warp direction. No. The warp yarn 7 of No. 5 is the weft yarn No. The weft yarns 6 of 1 to 8 pass in order under, over, under, over, over, over, under, and under. Warp No. The warp yarns 7 of No. 6 are the warp yarns No. 6. 5, two wefts 6 are used for the wefts No. 5. is woven into the weft yarn 6 while shifting to the larger one. Warp No. The warp yarns 7 of No. 7 are the warp yarns No. 7. 5, two wefts 6 are used for the wefts No. 5. is woven into the weft yarn 6 while shifting to the smaller one. Warp No. The warp yarns 7 of No. 8 are the warp yarns No. 8. It is woven into the weft 6 with a shift of four wefts 6 from the warp 7 of No. 5.

Please refer to FIG. 2(B) and FIG. Focusing on the pair of warp yarns 7 arranged so as to form two warp rows connected by the loop 4 near the ends in the warp direction, one of the pair of warp yarns 7 (warp yarns No. 8, 2, 4 and 6) are folded back to form a loop 4, and the portion of the folded portion 13 closer to the tip side than the loop 4 is woven into the ground portion 10. - 特許庁The tip end of the folded back portion 13 and the end of the other of the pair of warp yarns 7 (warp Nos. 1, 3, 5 and 7) are arranged so as to overlap each other in the main fabric portion 12 when viewed from the weft direction. (woven into the weft 6 of the common weft No.) to form a seam 14 (a portion surrounded by a broken line in the figure). At the seam 14 in the illustrated example, both ends overlap by 5 wefts 6 when viewed from the weft direction, but this number may be changed, and 5 to 13 wefts 6 overlap. preferably. Further, it is preferable that the seam 14 is arranged away from the loop portion 5 by a distance of 250 weft yarns 6 or more in the warp direction. Further, it is preferable that the seams 14 adjacent to each other in the weft direction are arranged so that their closest portions are separated from each other by a distance of 17 wefts 6 or more in the warp direction.

The warp yarns 7 in the end fabric portion 11 form a design with a larger crimp than the warp yarns 7 in the main fabric portion 12 . Referring to FIG. 5, the "large crimp design" of the warp yarns 7 will be described. 5(A) shows a comparative example, FIG. 5(B) shows the edge portion 11, and FIG. 5(C) shows the main portion 12. As shown in FIG. In a predetermined section, the larger the value obtained by dividing the lengths LA, LB, and LC of the warp yarns 7, 107 including the curved shape by the linear distance L in the extending direction (warp direction) of the warp yarns 7, 107 in that section , say "the crimp is big". In FIG. 5A, in the section of distance L, the warp 107 passes over the upper weft 108, passes under the lower weft 109, and then passes over the upper weft 108 again 1+5/8 times. repeated. In addition, since the upper weft 108 and the lower weft 109 are vertically aligned with each other, the thickness of the ground portion 110 is larger than that shown in FIGS. LA also increases. In FIG. 5(B), in the section of distance L, the warp yarn 7 passes over the upper weft yarn 8, then under the lower weft yarn 9, and again over the upper weft yarn 8. The pattern is 2+1/6 times. repeated. In FIG. 5C, the same pattern is repeated 1+5/8 times in the section of distance L. In FIG. Therefore, LB>LA>LC and LB/L>LA/L>LC/L. That is, the warp yarns 7 of the end portion 11 shown in FIG. 5(B) form the largest crimp structure, and the warp yarns 107 of the comparative example shown in FIG. 5(A) form the large crimp structure on the second noodle. The warp yarns 7 of the main fabric portion 12 shown in FIG. 5(C) form the smallest crimp design. Regarding the warp yarns 7, the "large crimp design" can be rephrased as "the bend angle of the warp yarns 7 at the knuckle portion where the warp yarns 7 weave the weft yarns 6 is small".

The inclination of the loop 4 will be described with reference to FIG. FIG. 6A shows the loop 104 according to the comparative example, and FIG. 6B shows the loop 4 according to the first embodiment. In the comparative example shown in FIG. 6A, the rows of warp yarns 107 are arranged at approximately equal intervals, so that the loops 104 are inclined at about 45° with respect to the thickness direction when viewed from the warp direction. In the first embodiment shown in FIG. 6(B), a pair of rows of warp yarns 7 that form loops 4 and are adjacent to each other are paired. That is, each row of warp yarns 7 is connected by the loops 4 and arranged closer to the adjacent row of warp yarns 7 and away from the adjacent row of warp yarns 7 on the opposite side. Therefore, the inclination of the loop 4 with respect to the thickness direction when viewed in the warp direction is smaller than 45°. Therefore, in the papermaking seam felt 1 (see FIG. 1) according to the first embodiment, the loops 4 provided at both ends thereof can be easily interlocked and joined.

Materials for forming the warp yarns 7, the upper weft yarns 8 and the lower weft yarns 9 are not particularly limited, but polyamide-based resins and polyester-based resins are preferable. The polyamide-based resin is preferably an aliphatic polyamide resin, more preferably nylon. Nylon includes 66 nylon, 6 nylon, 12 nylon, 11 nylon, 610 nylon, 612 nylon and the like. These may use only 1 type and may use 2 or more types together. The polyester-based resin is not particularly limited as long as it is polyester composed of dicarboxylic acid and glycol, and may be polyethylene terephthalate (PET), polypropylene terephthalate, polybutylene terephthalate (PBT), polyethylene naphthalate, or the like. These may use only 1 type and may use 2 or more types together. Further, the warp yarns 7, the upper weft yarns 8 and the lower weft yarns 9 may be made of the same material or may be made of different materials. Each thread may be made of a single material, or may be made of two or more different materials. Furthermore, each thread may contain an inorganic filler and/or an organic filler. The types of yarns of the warp yarn 7, the upper weft yarn 8 and the lower weft yarn 9 are not particularly limited, but may be, for example, monofilament single yarn, monofilament twisted yarn, multifilament twisted yarn, or a combination thereof. The diameter of the warp yarns 7 is preferably 0.29 mm to 0.39 mm, and the diameter of the weft yarns 6 is preferably 0.29 mm to 0.42 mm. Some of the warp yarns 7, some of the upper weft yarns 8 and/or some of the lower weft yarns 9, for example every other warp yarn 7, may use fluorescent yarns or colored yarns. The use of fluorescent thread or colored thread facilitates suturing of the loop portion 5 .

Please refer to FIGS. The base fabric 2 is manufactured by a worker performing the following steps. The base fabric 2 is woven using the warp yarns 7 as warp yarns and the weft yarns 6 as driving yarns. A portion of the warp yarn 7 to be the folded back portion 13 is formed by removing the weft yarn 6 from the end in the warp direction after weaving, or by not driving the weft yarn 6 into that portion. The tip of the corresponding warp yarn 7 is folded back to form a loop 4, and further, the part of the folded part 13 closer to the tip than the loop 4 is woven into the ground part 10 up to the seam 14.例文帳に追加After the seam 14 is formed, the portion of the folded portion 13 on the tip side of the seam 14 and the portion of the warp 7 forming the seam 14 with the folded portion 13 on the loop 4 side of the seam 14 are combined. cut the part. The cut ends are preferably arranged on the running surface side.

The effects of the base fabric 2 will be described with reference to FIGS. 1 to 6. FIG.

Since the warp yarns 7 form a structure with a larger crimp in the end fabric portion 11 than in the main fabric portion 12, the resistance to the coming off of the warp yarns 7 in the end fabric portion 11 is increased. Therefore, even if a force is applied to the warp yarn 7 in the direction of pulling it out from the loop 4, the warp yarn 7 is prevented from coming off.

The leading end of the folded back portion 13 and the end of the other warp yarn 7 overlap each other by the number of the weft yarns 6 of 5 to 13 to form a seam 14 . Therefore, a frictional force acts between the warp yarns 7 overlapping each other, and the part of the warp yarn 7 forming the seam 14 is prevented from coming off from the weft yarn 6 .

Since the main ground portion 12 is composed of a structure with a smaller crimp than the edge ground portion 11 , the paper surface property is better than that of the edge ground portion 11 . By providing the main base portion 12 having a design with relatively small crimps, the surface property of the base portion 10 is improved as compared with the case where the entire base portion 10 has a design with large crimps. Further, by setting the length of the edge portion 11 in the warp direction to 5 to 7 cm, the balance between the paper surface property and the prevention of the loop 4 from coming off is improved.

By arranging the weft yarns 6 at 13.8 to 17.7 per 1 cm in the warp direction, the balance between water squeezing, paper surface property and durability is improved.

Since the weaving pattern of each row of warp yarns 7 does not form a mirror-symmetrical shape with respect to a cross section perpendicular to the warp direction, the force applied from the warp yarns 7 to the weft yarns 6 is biased. However, warp No. 1 to 4 warp yarns 7 and warp yarn No. In rows 5 to 8 of the warp yarns 7, the weaving patterns of the warp yarns 7 are mirror-symmetrical to each other with respect to the cross section orthogonal to the warp direction, so forces are applied to the weft yarns 6 in mutually opposite directions. Therefore, the positions of the upper weft yarn 8 and the lower weft yarn 9 are stabilized at positions shifted from each other in the warp direction.

The ratio of the number of the upper wefts 8 to the number of the lower wefts 9 is 1:1, and the upper wefts 8 and the lower wefts 9 are alternately arranged at positions shifted in the warp direction. The compressibility in the thickness direction is lower than when the lower weft yarns 9 are aligned in the thickness direction. Therefore, the stretchability in the warp direction is low, and the dimensional stability is excellent.

In the vicinity of each end in the warp direction, the joint 14 is arranged at a distance of 250 wefts 6 or more from the loop portion 5, so that the folded portion 13 has a length of a predetermined value or more. It is woven into the weft yarn 6, and the effect of suppressing the coming off of the warp yarn 7 is enhanced.

In the vicinity of each end in the warp direction, the seams 14 adjacent to each other in the weft direction are arranged apart from each other by a distance of 17 wefts 6 or more in the warp direction, so that the warp yarns 7 are densely arranged. The positions of the seams 14 are dispersed, and deterioration of paper surface property and water squeezability due to the seams 14 is suppressed.

FIG. 7A shows a base portion 10 according to a modified example of the first embodiment. As shown in FIGS. 7B and 7C, the end base portion 11 and the main base portion 12 of the base fabric 2 of the main example of the first embodiment have a structure in which the duality of the wefts 6 is broken, that is, , the upper weft 8 and the lower weft 9 are arranged to be shifted in the warp direction. The ground portion 10 of the base fabric 2 according to the modified example is constituted by a design in which the wefts 6 are kept dual, that is, a design in which the upper wefts 8 and the lower wefts 9 are arranged in alignment with each other in the thickness direction. In the example shown in FIG. 7A, the warp yarn 7 repeatedly passes over the upper weft yarn 8, between the upper weft yarn 8 and the lower weft yarn 9, under the lower weft yarn 9, and between the upper weft yarn 8 and the lower weft yarn 9. is woven into the weft yarn 6 as shown in FIG. As another weaving pattern, although not shown, the warp yarn 7 repeats passing above the upper weft yarn 8, below the lower weft yarn 9, and between the upper weft yarn 8 and the lower weft yarn 9, and this weaving pattern. The tissue of has a larger crimp than the tissue shown in FIG. 7(A). As other weaving patterns, although not shown, the warp 7 is above the upper weft 8, between the upper weft 8 and the lower weft 9, between the upper weft 8 and the lower weft 9, below the lower weft 9, Repeated passage between the upper weft yarn 8 and the lower weft yarn 9 and between the upper weft yarn 8 and the lower weft yarn 9 can be mentioned, and the texture of this weaving pattern has smaller crimps than the texture shown in FIG. 7(A). The base fabric 2 according to the modified example uses such a structure in which the duplicity of the weft yarns 6 is maintained, and the warp yarns 7 in the end fabric portion 11 have a larger crimp than the warp yarns 7 in the main fabric portion 12. Form.

A second embodiment according to the present invention will now be described with reference to FIGS. In the description, only differences will be described for configurations common to and similar to those of the first embodiment, and the same reference numerals will be given. The seam felt base fabric 21 for papermaking according to the second embodiment (hereinafter referred to as "base fabric 21") has a base part 22, except for the part where the folded back part 23 is woven, by a single weave. It differs from the first embodiment in terms of configuration and the like.

The base fabric 21 includes weft yarns 6 including a plurality of upper weft yarns 8 and lower weft yarns 9 extending in the weft direction, and a plurality of warp yarns 7 extending in the warp direction and woven with the weft yarns 6 . Weft No. 1, 3, 5 and 7 weft rows are composed of the upper weft 8, and the weft No. 2, 4, 6, 8 weft rows are constituted by the lower weft yarn 9 .

The base fabric 21 includes loop portions 5 provided at both ends in the warp direction, and a ground portion 22 disposed between the two loop portions 5 and in which the weft yarns 6 and the warp yarns 7 are woven.

The warp yarns 7 are woven into the weft yarns 6 in the base portion 22 in the same manner as the main base portion 12 (see FIG. 2) of the first embodiment except for the folded portion 23 . The folded-back portion 13 is woven into the weft yarn 6 in the same weaving pattern as the end ground portion 11 of the first embodiment, except for the loops 4 and seams 14 . Other portions of the warp yarns 7 in the base portion 22 are woven into the weft yarns 6 in the same weaving pattern as in the main base portion 12 of the first embodiment. The folded back portion 23 is the warp yarn No. It constitutes a part of the 1st, 3rd, 5th and 7th warp rows.

In the ground portion 22, the portion excluding the seam 14 in the folded portion 23 is above the upper weft 8, above the lower weft 9, below the upper weft 8, below the lower weft 9, and above the upper weft 8. It is woven into the weft yarn 6 so as to repeatedly pass over the lower and lower weft yarns 9. - 特許庁Warp No. The folded portion 23 of the warp row No. 3 is the warp yarn No. 3. Two wefts 6 of the weft No. 1 are applied to the folded portion 23 of the warp row No. 1. is woven into the weft yarn 6 while shifting to the smaller one. Warp No. The folded back portion 23 of the warp row No. 5 is the warp yarn No. 5. Two wefts 6 of the weft No. 1 are applied to the folded portion 23 of the warp row No. 1. is woven into the weft yarn 6 while shifting to the larger one. Warp No. A portion 23 of the warp row No. 7 is folded back. It is woven into the weft yarn 6 in the same manner as the folded portion 23 of the warp row 1.

Focusing on a pair of warp yarns 7 arranged to form two warp rows connected by a loop 4, one of the pair of warp yarns 7 (warp Nos. 8, 2, 4 and 6) is folded back. A portion of the folded portion 23 that forms the loop 4 and is closer to the tip than the loop 4 is woven into the ground portion 22 . The tip end of the folded back portion 23 and the end of the other of the pair of warp yarns 7 (warp Nos. 1, 3, 5 and 7) are arranged so as to overlap each other in the ground portion 22 when viewed from the weft direction. (woven into the weft 6 of the common weft No.), and a seam 14 (a portion surrounded by a broken line in the figure) is formed. The length and arrangement of the seams 14 are the same as in the first embodiment. The weaving manner of the warp yarns 7 at the seam 14 follows the weaving pattern of the warp yarns 7 on the center side in the warp direction of the seam 14 .

In the ground portion 22, the folded back portion 23 excluding the seam 14 is the other portion (the seam 14, the portion on the center side in the warp direction from the seam 14 of warp Nos. 1, 3, 5, and 7, And, the warp yarn No. 8, 2, 4, 6) forms a larger crimp design. For this reason, the resistance to the falling off of the folded portion 23 is increased. Therefore, even if a force is applied to the warp yarn 7 in the direction of pulling it out from the loop 4, the warp yarn 7 is prevented from coming off. When a tensile force is applied to the loop 4, it is the folded back portion 23 that is likely to come off from the base portion 22. - 特許庁Therefore, in a pair of warp yarns 7 adjacent to each other to form a loop 4, even if the crimp of the warp yarn 7 on the side opposite to the folded portion 23 is small, the effect of preventing the warp yarn 7 from coming off is small. In addition, in the vicinity of the edge of the base fabric 21, since the crimp of the warp yarns 7 on the side opposite to the folded portion 23 in the pair of warp yarns 7 is small, the paper surface property is improved.

Example 1 corresponding to the first embodiment; Example 2 corresponding to the second embodiment; For the obtained comparative example (the seam arrangement is the same as in Example 1), a sample was set in a strograph under the following test conditions, and a tensile test was performed on the strength of the base fabric including the loop portion.
<Test conditions>
Sample size: length 75 cm x width 3 cm
Test length: 65 cm (Set in the strograph centering on the core wire)
Test width: Width 2.5 cm (match the number of warps for 2.5 cm)
Test speed: 200mm/min

The test results were as follows. In Examples 1 and 2, about 1.25 to 1.35 times as much force was required to remove the warp as compared to the comparative example.
<Results>
Example 1: 35.6 kg/cm
Example 2: 38.2 kg/cm
Comparative example: 28.4 kg/cm

Although the specific embodiments have been described above, the present invention is not limited to the above-described embodiments and modifications, and can be widely modified. Papermaking seam felts may also be used in papermaking machines other than paper machines, such as pulp machines. The way in which the warp and weft threads are woven may be changed within the range that satisfies the above conditions regarding the size of the crimp. In the base portion of the second embodiment, not the entire folded portion except for the seams, but a portion thereof may form a structure with a larger crimp than the other portions. Instead of being formed by superimposing two warp threads, the seam may be configured such that the tips of the two warp threads meet.

2, 21: papermaking seam felt base fabric 4: loop 5: loop portion 6: weft 7: warp 8: upper weft 9: lower weft 10, 22: base 11: end base 12: main base 13, 23: Folded portion 14: Seam

Claims (9)

A weft including an upper weft extending in the weft direction and a lower weft disposed on the running surface side of the upper weft and extending in the weft direction, and a warp extending in the warp direction and woven with the weft. A papermaking seam felt base fabric comprising
A ground portion in which the weft yarns weave the warp yarns, and loop portions protruding from both ends of the ground portion in the warp direction,
The loop portion includes a plurality of loops formed by folding back the warp,
In the pair of warp yarns arranged to form two warp rows connected by the loop near the ends in the warp direction, one of the pair of warp yarns is folded back to form the loop. , the tip side end portion of the one folded portion and the other end portion of the pair of warp yarns are arranged so as to overlap or face each other when viewed from the weft direction in the ground portion. By forming a seam,
In the pair of warp yarns, at least a portion of the folded back portion of the one of the warp yarns forms a larger crimped structure than the portion located at the center in the warp direction from the seam. Felt base. wherein said ground portion includes an end ground portion located adjacent to each of said loop portions and a main ground portion located between two said end ground portions;
The seam is formed in the main base portion,
2. The papermaking seam felt base fabric according to claim 1, wherein the warp yarns in the end portion fabric form a larger crimp structure than the warp yarns in the main fabric portion. 3. The seam felt base fabric for papermaking according to claim 2, wherein the length between the wefts arranged at both ends in the warp direction in the end base portion is 5 to 7 cm. 2. The papermaking method according to claim 1, wherein, in the base portion, the portion of the folded back portion excluding the seam forms a larger crimp design than the other portions of the pair of warp yarns. Seam-felt base fabric for . The seam felt base fabric for papermaking according to any one of claims 1 to 4, wherein the weft yarns are arranged at 13.8 to 17.7 per cm in the warp direction. The seam is formed by overlapping the end portion of the one folded portion and the other end portion by 5 to 13 weft yarns when viewed from the weft direction. The seam felt base fabric according to any one of claims 1 to 5, wherein The seam felt according to any one of claims 1 to 6, wherein near each end in the warp direction, the seam is arranged at a distance of 250 wefts or more from the loop portion. Base cloth. In the vicinity of each end in the warp direction, the seams adjacent to each other in the weft direction are arranged so that the closest portions thereof are separated from each other by a distance of 17 wefts or more in the warp direction. The seam felt base fabric according to any one of claims 1 to 7. The ratio of the number of upper wefts to the number of lower wefts is 1:1,
The seam felt base fabric according to any one of claims 1 to 8, wherein the upper weft and the lower weft are alternately arranged at positions shifted in the warp direction.

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