Method for manufacturing a base fabric for papermaking felts with a joint ring and base fabric obtained thereby
By folding and combining the base fabric and adjusting the number of weft yarns to form symmetrical seam rings, the problem of warp yarn deformation is solved, the stability of the seam rings and the convenience of core yarn insertion are achieved, and seam marks are avoided during wet paper dehydration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ICHIKAWA CO LTD
- Filing Date
- 2024-11-18
- Publication Date
- 2026-06-02
AI Technical Summary
In the existing technology for manufacturing base fabric for papermaking felt with seam rings, the warp yarns that make up the seam rings are prone to deformation, causing the seam rings to collapse and making it impossible to insert the core yarns.
The base fabric is folded to form loops, and then the weft yarns inside the loops are removed. The number of weft yarns is adjusted to ensure that the mechanical length of the warp loop relative to the CD axis of the seam loop reaches more than 50%, thus forming a symmetrical seam loop.
The seam ring is manufactured to prevent warp yarns from deforming and maintain a good shape, making it easy to insert the core yarn and preventing seam marks from forming when wet paper is dehydrated.
Smart Images
Figure CN122139059A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for manufacturing a base fabric for papermaking blankets having a seam ring, and the base fabric obtained therefrom. Background Technology
[0002] In the press section of a conventional paper machine, water is squeezed from the wet paper using a press blanket and a pair of press rolls, or press rolls and a shoe press. Such press blankets are known to include... Figure 1 The illustration shows an end-shaped blanket with seam loops. That is, the blanket F is constructed with ends, each end having multiple seam loops L. The blanket F, for example, is... Figure 2 As shown, the fabric consists of a base fabric B and two pile layers W. The pile layers W are formed by needle punching short fibers layered on the base fabric B and entangled together with it. The base fabric B is a woven fabric composed of yarn material interwoven along the blanket's travel direction (mechanical direction: MD) and yarn material along the blanket's transverse direction (mechanical direction: CD). Furthermore, the seam ring L is composed of yarn material in the MD direction. Inside the seam ring L, a core yarn S is inserted along the CD direction.
[0003] As a method for manufacturing a base fabric with a seam loop, there are known methods including: removing weft yarns from a base fabric composed of warp yarns in the mechanical direction and weft yarns in the mechanical transverse direction and folding it, joining a portion of the base fabric to form a seam loop (Patent Document 1); and removing weft yarns before and after folding a plain weave fabric and sewing a portion of the plain weave fabric to form a loop (Patent Document 2).
[0004] Existing technical documents Patent documents Patent Document 1: US Patent No. 8,353,252 Patent Document 2: International Publication No. 89 / 012717 Summary of the Invention
[0005] Technical issues When the inventors manufactured a base fabric with a seam ring by removing the weft yarn from the base fabric and folding it, and joining a portion of the base fabric to form a seam ring, they faced the following problem: the warp yarns constituting the seam ring deformed, the seam ring collapsed, and the core yarn could not be inserted.
[0006] Therefore, the inventors have researched a method for manufacturing a base fabric for papermaking felt with seam loops, a method that prevents the warp yarns constituting the seam loops from deforming, maintains a good shape for the seam loops, and facilitates the insertion of core yarns. In other words, the objective of this invention is to provide a method for manufacturing a base fabric for papermaking felt with seam loops, a method that maintains a good shape for the seam loops and facilitates the insertion of core yarns.
[0007] Technical solution In the course of conducting in-depth research to solve the above-mentioned problems, the inventors discovered that by folding the base fabric and joining it in a loop, and then removing the weft yarns inside the loop to form a seam loop, it is possible to manufacture a base fabric for papermaking blankets with a seam loop that does not deform the warp yarns forming the seam loop, maintains a good shape, and is easy to insert the core yarn. Furthermore, it was found that when the base fabric is a plain weave fabric and the number of weft yarns removed is odd, it is possible to manufacture a base fabric for papermaking blankets with a seam loop that has a better shape.
[0008] The inventors further discovered that, regardless of whether the window is formed by removing weft yarns from the base fabric and then folding it to join a portion of the base fabric to form a seam ring, or whether the base fabric is folded and joined to form a ring, and then the weft yarns inside the ring are removed to form a window and a seam ring, by adjusting the number of weft yarns removed, the proportion of warp yarns whose length is symmetrical in the mechanical direction (MD) relative to the CD axis (the axis that connects the center point of the window in the mechanical direction along the mechanical transverse direction) of the seam ring reaches 50% or more, thereby enabling the manufacture of a base fabric for papermaking blankets with a well-shaped seam ring; and further research was conducted, resulting in this invention.
[0009] That is, the present invention relates to the following.
[0010] [1] A method for manufacturing a base fabric for papermaking blankets with seam rings, comprising: A process for providing a base fabric for papermaking felt, the base fabric comprising a plurality of warp yarns extending in the mechanical direction (MD) and a plurality of weft yarns extending in the mechanical transverse direction (CD) interwoven with the plurality of warp yarns. The process of folding the papermaking blanket at any two points with the base fabric so that each of the multiple warp yarns is substantially aligned with itself on the MD. The process of joining the ends of the base fabric of the papermaking felt together to form a joint; Near each fold, the papermaking felt is joined with a portion of the base fabric in a loop-like manner; The process of removing the weft yarn within the ring from the base fabric for the papermaking felt to define the seam ring.
[0011] [2] The method as described in [1] further includes the step of: substantially aligning at least one weft yarn on one side with the corresponding weft yarn on the other side near the position where the yarns are joined in a loop-forming manner.
[0012] [3] The method as described in [1] or [2], wherein the base fabric for the papermaking blanket is a plain weave fabric and the number of weft yarns removed is odd.
[0013] [4] The method as described in any one of [1] to [3], wherein the warp yarn is a monofilament.
[0014] [5] The method as described in [4], wherein the monofilament has a fineness of 800 dtex or more.
[0015] [6] The method as described in any one of [1] to [5], wherein the weft yarn is a monofilament.
[0016] [7] The method as described in [6], wherein the monofilament has a fineness of 800 dtex or more.
[0017] [8] A base fabric for papermaking blankets having a seam ring, obtained by any one of [1] to [7].
[0018] [9] A papermaking blanket, the base material of which comprises a papermaking blanket base fabric having a seam ring as described in [8].
[0019]
[10] Papermaking blanket as described in [9], wherein the papermaking blanket base fabric with seam ring as described in [8] is disposed on the outermost layer of the base material of the papermaking blanket.
[0020]
[11] Papermaking blanket as described in [9] or
[10] , wherein the base material of the papermaking blanket consists of two layers, an outer layer and an inner layer, and a papermaking blanket base fabric with a seam ring as described in [8] is disposed on the outer layer of the base material.
[0021]
[12] The papermaking felt as described in
[11] , wherein the joint of the papermaking felt base fabric with a seam ring disposed on the outer layer of the substrate is located on the wet paper side.
[0022]
[13] The papermaking felt as described in
[11] , wherein the joint of the papermaking felt base fabric with a seam ring disposed on the outer layer of the substrate is located on the roll side.
[0023]
[14] The papermaking felt as described in
[11] , wherein the papermaking felt base fabric disposed in the inner layer of the substrate and the papermaking felt base fabric with seam ring disposed in the outer layer of the substrate are of the same type and have a joint obtained by joining the ends of the base fabrics together.
[0024]
[15] The papermaking felt as described in
[14] , wherein one or more of the joint portion of the papermaking felt base fabric with a seam ring disposed on the outer layer of the substrate and the joint portion of the papermaking felt base fabric disposed on the inner layer of the substrate are located on the wet paper side.
[0025]
[16] The papermaking felt as described in
[14] , wherein one or more of the joint portion of the papermaking felt base fabric with a seam ring disposed on the outer layer of the substrate and the joint portion of the papermaking felt base fabric disposed on the inner layer of the substrate are located on the roll side.
[0026]
[17] A method for manufacturing a base fabric for papermaking blankets with seam rings, comprising: (a) A process of providing a base fabric for papermaking felt, the base fabric comprising a plurality of warp yarns extending in the mechanical direction (MD) and a plurality of weft yarns extending in the mechanical transverse direction (CD) interwoven with the plurality of warp yarns; (b) The process of forming a seam ring in the base fabric for papermaking felt; Process (b) includes: (1-1) The process of folding the papermaking blanket at any two points with the base fabric so that each of the multiple warp yarns is substantially aligned with itself on the MD. (1-2) The process of joining the papermaking felt with a portion of the base fabric in a loop near each fold; and (1-3) The process of removing the weft yarns in the ring from the base fabric for papermaking blankets to form a window and delineate the seam ring, wherein, by adjusting the number of weft yarns removed, the proportion of warp yarns whose length is symmetrical in the mechanical direction (MD) relative to the CD axis (the axis that connects the center point of the mechanical direction of the window along the mechanical transverse direction) of the seam ring reaches 50% or more. or, (2-1) The process of removing the weft yarn at any two points of the base fabric for papermaking felt to define the window; (2-2) The process of folding the papermaking felt at each of the windows with a base fabric so that each of the multiple warp yarns is substantially aligned with itself on the MD; and (2-3) Near each fold, the papermaking blanket is joined with a portion of the base fabric in a loop-forming manner, wherein the proportion of warp loops with symmetrical length in the mechanical direction (MD) relative to the CD axis of the seam loop reaches more than 50% by adjusting the number of weft yarns removed. (c) The process of joining the ends of the base fabric of the papermaking felt together to form a joint.
[0027]
[18] The method as described in
[17] , wherein the number of weft yarns removed is 3 or more.
[0028]
[19] The method as described in
[17] or
[18] , wherein the number of weft yarns removed is 9 or less.
[0029]
[20] The method of any one of
[17] to
[19] , wherein the base fabric for the papermaking blanket is a plain weave or a twill weave.
[0030]
[21] The method as described in
[20] , wherein the base fabric for the papermaking blanket is a plain weave fabric and the number of weft yarns removed is an odd number.
[0031]
[22] The method as described in
[20] , wherein the base fabric for the papermaking blanket is a twill fabric, and the number of weft yarns removed is 3, 4, 6 or 7.
[0032]
[23] The method of any one of
[17] to
[22] further includes a step of substantially aligning at least one weft yarn on one side with the corresponding weft yarn on the other side near the position where the yarn is joined in a loop-forming manner.
[0033]
[24] The method as described in any one of
[17] to
[23] , wherein the warp yarn is a monofilament.
[0034]
[25] The method as described in
[24] , wherein the monofilament has a fineness of 800 dtex or more.
[0035]
[26] The method as described in any one of
[17] to
[25] , wherein the weft yarn is a monofilament.
[0036]
[27] The method as described in
[26] , wherein the monofilament has a fineness of 800 dtex or more.
[0037]
[28] A base fabric for papermaking blankets having seam rings, obtained by any one of
[17] to
[27] .
[0038]
[29] A papermaking blanket, the substrate of which comprises a papermaking blanket base fabric having a seam ring as described in
[28] .
[0039]
[30] Papermaking blanket as described in
[29] , wherein the papermaking blanket base fabric with seam ring as described in
[28] is disposed on the outermost layer of the base material of the papermaking blanket.
[0040]
[31] Papermaking blanket as described in
[29] or
[30] , wherein the substrate of the papermaking blanket consists of two layers, an outer layer and an inner layer, and the outer layer of the substrate is provided with a papermaking blanket base fabric having a seam ring as described in
[28] .
[0041]
[32] The papermaking felt as described in
[31] , wherein the joint of the papermaking felt base fabric with a seam ring disposed on the outer layer of the substrate is located on the wet paper side.
[0042]
[33] The papermaking felt as described in
[31] , wherein the joint of the papermaking felt base fabric with a seam ring disposed on the outer layer of the substrate is located on the roll side.
[0043]
[34] The papermaking felt as described in
[31] , wherein the papermaking felt base fabric disposed in the inner layer of the substrate and the papermaking felt base fabric with seam ring disposed in the outer layer of the substrate are of the same type, and have a joint obtained by joining the ends of the base fabrics together.
[0044]
[35] The papermaking felt as described in
[34] , wherein one or more of the joint portion of the papermaking felt base fabric with a seam ring disposed on the outer layer of the substrate and the joint portion of the papermaking felt base fabric disposed on the inner layer of the substrate are located on the wet paper side.
[0045]
[36] The papermaking felt as described in
[34] , wherein one or more of the joint portion of the papermaking felt base fabric with a seam ring disposed on the outer layer of the substrate and the joint portion of the papermaking felt base fabric disposed on the inner layer of the substrate are located on the roll side.
[0046] The effects of the invention In the manufacturing method of the papermaking blanket base fabric with seam ring of the present invention, the base fabric is folded and joined in a way that forms a ring, and then the weft yarn inside the ring is removed to form the seam ring. This makes it possible to manufacture a papermaking blanket base fabric with seam ring in which the warp yarn constituting the seam ring does not deform, maintains a good shape, and is easy to insert the core yarn.
[0047] In the method for manufacturing a papermaking blanket base fabric with seam rings according to the present invention, when the base fabric is a plain weave fabric and the number of weft yarns removed is odd, a papermaking blanket base fabric with seam rings of better shape can be manufactured.
[0048] In the manufacturing method of the papermaking blanket base fabric with seam ring of the present invention, whether it is formed by removing weft yarns from the base fabric to form a window and then folding it and combining a part of the base fabric to form a seam ring, or by folding the base fabric, combining it in a way that forms a ring, and then removing the weft yarns in the ring to form a window and form a seam ring, it is possible to adjust the number of weft yarns removed so that the proportion of warp yarns whose length in the mechanical direction (MD) of the warp yarn ring is symmetrical with respect to the CD axis of the seam ring reaches 50% or more, thereby manufacturing a papermaking blanket base fabric with a good-shaped seam ring.
[0049] When the papermaking felt base fabric with seam rings obtained by the method of the present invention is used for papermaking felts, it is possible to prevent seam marks that may occur on the wet paper side of the seam rings during wet paper dehydration. Attached Figure Description
[0050] Figure 1 This is a schematic diagram of the seam blanket used for papermaking.
[0051] Figure 2 It is a diagram illustrating the interlocking operation of the seam blanket used in papermaking.
[0052] Figure 3 This is a top view of the seam ring of a papermaking blanket base fabric manufactured by a comparative example method.
[0053] Figure 4 This is a top view of the seam ring of the base fabric for papermaking blankets manufactured by method 1 of the present invention.
[0054] Figure 5 This is a mechanical transverse side view of the seam ring of the base fabric for papermaking felt, manufactured by method 1 of the present invention. The left side of the figure is a side view when an odd number of weft yarns are removed, and the right side of the figure is a side view when an even number of weft yarns are removed.
[0055] Figure 6 This is a mechanical transverse side view illustration of the seam ring of a papermaking blanket base fabric with a seam ring manufactured by method 2 of the present invention (removing 7 weft yarns from a plain weave fabric base fabric).
[0056] Figure 7 This is a mechanical transverse side view (photographed at 20x magnification) of the seam ring of a papermaking blanket base fabric with seam ring manufactured by method 2 of the present invention (removing 7 weft yarns from a plain weave base fabric).
[0057] Figure 8 This is a mechanical transverse side view illustration of the seam ring of a papermaking blanket base fabric with a seam ring manufactured by method 2 of the present invention (removing 7 weft yarns from a twill fabric base fabric).
[0058] Figure 9 This is a mechanical transverse side view (photographed at 20x magnification) of the seam ring of a papermaking blanket base fabric with seam ring manufactured by method 2 of the present invention (removing 7 weft yarns from the twill fabric base fabric).
[0059] Figure 10 This is a mechanical transverse side view illustration of the seam ring of a papermaking blanket base fabric with a seam ring manufactured by method 2 of the present invention (removing 6 weft yarns from a twill fabric base fabric).
[0060] Figure 11 This is a mechanical transverse side view (photographed at 20x magnification) of the seam ring of a papermaking blanket base fabric with seam ring manufactured by method 2 of the present invention (removing 6 weft yarns from the twill fabric base fabric). Detailed Implementation
[0061] The present invention will now be described in detail based on preferred embodiments.
[0062] Method 1 of the present invention This invention relates to a method for manufacturing a base fabric for papermaking blankets with seam rings, comprising: A process for providing a base fabric for papermaking felt, the base fabric comprising a plurality of warp yarns extending in the mechanical direction (MD) and a plurality of weft yarns extending in the mechanical transverse direction (CD) interwoven with the plurality of warp yarns. The process of folding the papermaking blanket at any two points with the base fabric so that each of the multiple warp yarns is substantially aligned with itself on the MD. The process of joining the ends of the base fabric of the papermaking felt together to form a joint; Near each fold, the papermaking felt is joined with a portion of the base fabric in a loop-like manner; The process of removing the weft yarn within the ring from the base fabric for the papermaking felt to define the seam ring.
[0063] Method 1 of the present invention includes the step of providing a base fabric for papermaking felt, the base fabric comprising a plurality of warp yarns extending in the mechanical direction (MD) and a plurality of weft yarns extending in the mechanical transverse direction (CD) interwoven with the plurality of warp yarns.
[0064] The base fabric for papermaking felt comprises multiple warp yarns extending in the mechanical direction (MD) and multiple weft yarns extending in the mechanical transverse direction (CD) interwoven with the multiple warp yarns.
[0065] There are no particular restrictions on the weaving method of the base fabric. Examples include plain weave fabric, twill weave (yarn weave), twill weave (twill pattern weave), and satin weave fabric. From the perspective of maintaining the ring shape and the uniformity of the ring arrangement, plain weave fabric is preferred.
[0066] The warp yarn can be monofilament or twisted yarn, but monofilament is preferred from the viewpoint of forming and maintaining a well-shaped seam loop. There are no particular limitations on the material constituting the warp yarn; it can be polyester (polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), aliphatic polyamides (polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 612, etc.), aromatic polyamides (aramid), polyvinylidene fluoride, polypropylene, polyetheretherketone, polytetrafluoroethylene, polyethylene, wool, cotton, metal, etc. The warp yarn can be made from one material alone or in combination of two or more materials.
[0067] From the viewpoint of balancing strength retention and dimensional stability during use, the warp yarn preferably includes one or more selected from the group consisting of polyester, aliphatic polyamide and aromatic polyamide (aramid), and more preferably includes one or more selected from the group consisting of polyethylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610 and polyamide 612.
[0068] Furthermore, the fineness of the warp yarn is not particularly limited, but is between 200 dtex and 6000 dtex, preferably between 500 dtex and 3000 dtex. From the viewpoint of maintaining strength, dimensional stability, and compression recovery during use, it is preferably between 800 dtex and 2500 dtex.
[0069] The weft yarn can be monofilament or twisted yarn. From the viewpoint of balancing strength maintenance and dimensional stability, monofilament is preferred, while twisted yarn is preferred to prevent shedding of the wool layer fibers. There are no particular limitations on the materials constituting the weft yarn; they can be polyester (polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), aliphatic polyamides (polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 612, etc.), aromatic polyamides (aramid), polyvinylidene fluoride, polypropylene, polyetheretherketone, polytetrafluoroethylene, polyethylene, wool, cotton, metal, etc. The weft yarn can use one type of material alone or two or more materials in combination.
[0070] From the viewpoint of balancing strength retention and dimensional stability during use, the weft yarn preferably includes one or more selected from the group consisting of polyester, aliphatic polyamide and aromatic polyamide (aramid), and more preferably includes one or more selected from the group consisting of polyethylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610 and polyamide 612.
[0071] Furthermore, when the weft yarn is a monofilament, its fineness is not particularly limited, but is between 200 dtex and 6000 dtex, preferably between 500 dtex and 3000 dtex. From the viewpoint of maintaining strength, dimensional stability, and compression recovery during use, it is preferably between 800 dtex and 2500 dtex. Furthermore, when the weft yarn is a twisted yarn, its fineness is not particularly limited, but it is preferable to twist multiple yarns of 100 dtex to 500 dtex together, with a fineness of 200 dtex to 6000 dtex, preferably between 500 dtex and 3000 dtex, and more preferably between 800 dtex and 2500 dtex.
[0072] In addition, considering factors such as strength retention, dimensional stability, compression recovery, and prevention of fiber shedding during use, monofilaments and twisted yarns can be mixed into the weft yarn. The mixing ratio can be set from 100:0 to 0:100.
[0073] Method 1 of the present invention includes a step of folding a papermaking blanket at any two points with a base fabric so that multiple warp yarns are substantially aligned with themselves on the MD.
[0074] In this specification, "substantially aligned" means that after the base fabric is folded at a predetermined position in the mechanical direction, the warp yarns on one side (wet paper side) and the corresponding warp yarns on the other side (roller side) are located in the same position in the transverse direction of the machine and are substantially parallel. It also means that after the base fabric is folded at a predetermined position in the mechanical direction, the weft yarns on one side (wet paper side) and the corresponding weft yarns on the other side (roller side) are located in the same position in the mechanical direction and are substantially parallel.
[0075] Method 1 of the present invention includes a step of joining the ends of a base fabric for papermaking felt together to form a joint.
[0076] There are no particular limitations on the means of joining the ends of the base fabric for papermaking felt together, such as welding, bonding, sewing, etc. From the viewpoint of work efficiency and strength preservation, welding is preferred, and ultrasonic welding is particularly preferred.
[0077] Method 1 of the present invention includes a step of joining a portion of the papermaking felt base fabric in a loop near each fold.
[0078] In this specification, "fold" means the folding of the base fabric for papermaking felt in the mechanical direction, and "folded portion" refers to any two points (two positions) of the base fabric for papermaking felt in the mechanical direction. This process means that, starting from the folded portion, at a position away from a predetermined distance in the mechanical direction, the base fabric on the wet paper side and the base fabric on the roll side are joined together in a loop in the transverse direction of the machine.
[0079] There are no particular limitations on the bonding method; for example, sewing, welding, and bonding using a sewing machine are acceptable. However, from the perspectives of work efficiency, ensuring breathability, and improving seam appearance, sewing using a sewing machine is preferred. When using a sewing machine, there are no particular limitations on the yarn used. Both the top and bottom threads can be polyester (polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), aliphatic polyamides (polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 612, etc.), aromatic polyamides (aramid), polyvinylidene fluoride, polypropylene, polyetheretherketone, polytetrafluoroethylene, polyethylene, wool, cotton, metal, etc. One type of yarn can be used alone, or two or more types can be used in combination for the top and bottom threads. The top and bottom threads can be the same yarn or different yarns.
[0080] Method 1 of the present invention includes the step of removing the weft yarns inside the loop from the base fabric for papermaking felt to define the seam loop.
[0081] In this instruction manual, the seam ring is a loop used to insert the core yarn and splice the papermaking felt base fabric with another papermaking felt base fabric. The weft yarn needs to be appropriately removed from inside the ring so that the seam ring can be marked.
[0082] From the viewpoint of ease of core insertion, it is preferable to remove at least a number of adjacent weft yarns near the fold, and more preferably to remove almost all the weft yarns inside the loop.
[0083] The number of weft yarns removed depends on the size of the loop and the size of the inserted core yarn, and there is no particular limitation. For example, 2, 5, 8, 10, 13, etc. can be removed sequentially from near the fold. From the viewpoint of ease of core yarn insertion, it is preferable to remove an odd number of yarns sequentially from near the fold, and more preferably 3, 5, 7, or 9 yarns from near the fold.
[0084] In particular, when the base fabric is a plain weave, i.e., the warp and weft yarns are woven in a 1:1 alternating cross pattern, if the number of removed weft yarns is odd from the vicinity of the fold, then the center (apex) of each seam loop is located at the height of the fold, and the center (apex) of the seam loop is continuous at the height of the fold, making it easy to insert the core yarn. On the other hand, if the number of removed yarns is even from the vicinity of the fold, then the center (apex) of each seam loop may shift above or below the height of the fold, resulting in discontinuous center (apex) of the seam loop and making it difficult to insert the core yarn.
[0085] Method 2 of the present invention The present invention also relates to a method for manufacturing a base fabric for papermaking blankets having a seam ring, comprising: (a) A process of providing a base fabric for papermaking felt, the base fabric comprising a plurality of warp yarns extending in the mechanical direction (MD) and a plurality of weft yarns extending in the mechanical transverse direction (CD) interwoven with the plurality of warp yarns; (b) The process of forming a seam ring in the base fabric for papermaking felt; Process (b) includes: (1-1) The process of folding the papermaking blanket at any two points with the base fabric so that each of the multiple warp yarns is substantially aligned with itself on the MD. (1-2) The process of joining the papermaking felt with a portion of the base fabric in a loop near each fold; and (1-3) The process of removing the weft yarns in the ring from the base fabric for papermaking blankets to form a window and delineate the seam ring, wherein, by adjusting the number of weft yarns removed, the proportion of warp yarns whose length is symmetrical in the mechanical direction (MD) relative to the CD axis (the axis that connects the center point of the mechanical direction of the window along the mechanical transverse direction) of the seam ring reaches 50% or more. or, (2-1) The process of removing the weft yarn at any two points of the base fabric for papermaking felt to define the window; (2-2) The process of folding the papermaking felt at each of the windows with a base fabric so that each of the multiple warp yarns is substantially aligned with itself on the MD; and (2-3) Near each fold, the papermaking blanket is joined with a portion of the base fabric in a loop-forming manner, wherein the proportion of warp loops with symmetrical length in the mechanical direction (MD) relative to the CD axis of the seam loop reaches more than 50% by adjusting the number of weft yarns removed. (c) The process of joining the ends of the base fabric of the papermaking felt together to form a joint.
[0086] Method 2 of the present invention includes: (a) a step of providing a base fabric for papermaking felt, the base fabric comprising a plurality of warp yarns extending in a mechanical direction (MD) and a plurality of weft yarns extending in a mechanical transverse direction (CD) interwoven with the plurality of warp yarns.
[0087] The base fabric for papermaking felt comprises multiple warp yarns extending in the mechanical direction (MD) and multiple weft yarns extending in the mechanical transverse direction (CD) interwoven with the multiple warp yarns.
[0088] The weave structure of the base fabric for papermaking blankets is not particularly limited, such as plain weave, twill weave (yarn weave), twill weave (striped weave), satin weave, etc., with plain weave and twill weave being preferred. As for twill weave, examples include three-end twill (2 / 1 variation twill, etc.) and four-end twill (2 / 2 variation twill, 3 / 1 variation twill), etc., with 2 / 2 variation twill being preferred.
[0089] The structure, material, fineness, etc. of the warp and weft yarns can be as described in method 1 of the present invention.
[0090] Method 2 of the present invention includes: (b) a step of forming a seam ring in the base fabric for papermaking felt. The step of forming the seam ring can be either Mode 1 or Mode 2.
[0091] Mode 1 includes: (1-1) The process of folding the papermaking blanket at any two points with the base fabric so that each of the multiple warp yarns is substantially aligned with itself on the MD. (1-2) The process of joining the papermaking felt with a portion of the base fabric in a loop near each fold; and (1-3) The process of removing the weft yarns in the ring from the base fabric for papermaking blankets to form a window and delineate the seam ring, wherein, by adjusting the number of weft yarns removed, the proportion of warp yarns whose length is symmetrical in the mechanical direction (MD) of the warp ring relative to the CD axis (the axis that connects the center point of the mechanical direction of the window along the mechanical transverse direction) of the seam ring reaches 50% or more.
[0092] Mode 2 includes: (2-1) The process of removing the weft yarn at any two points of the base fabric for papermaking felt to define the window; (2-2) The process of folding the papermaking felt at each of the windows with a base fabric so that each of the multiple warp yarns is substantially aligned with itself on the MD; and (2-3) Near each fold, a portion of the papermaking blanket is joined in a loop-forming manner, wherein the number of weft yarns removed is adjusted so that the proportion of warp yarns whose length is symmetrical in the mechanical direction (MD) of the CD axis relative to the seam ring reaches 50% or more.
[0093] In either Mode 1 or Mode 2, the combination means may be as described in Method 1 of the present invention.
[0094] In either Mode 1 or Mode 2, the CD axis of the seam ring refers to the axis that connects the centers of the window's mechanical direction along the mechanical transverse direction.
[0095] In either Mode 1 or Mode 2, a "warp loop" refers to the warp portion on the CD axis created by removing the weft yarn.
[0096] When the proportion of warp yarns whose length in the mechanical direction (MD) relative to the CD axis is symmetrical is 50% or more in the seam loops, more than 50% of the vertices of each seam loop are at the same height, making it easy to insert the core yarn. On the other hand, when the proportion of warp yarns whose length in the mechanical direction (MD) relative to the CD axis is symmetrical is less than 50%, the proportion of the vertices of each seam loop at different heights is greater than the proportion at the same height, making it difficult to insert the core yarn.
[0097] In either Mode 1 or Mode 2, the number of weft yarns removed depends on the size of the loop and the size of the inserted core yarn. As long as the proportion of warp yarns that make the mechanical direction (MD) length of the warp loop relative to the CD axis of the seam loop symmetrical is more than 50%, there is no particular limitation. It can be multiple adjacent yarns near the fold, such as 3, 4, 5, 6, 7, etc., starting from the vicinity of the fold.
[0098] From the perspective of seam strength, it is preferable to remove at least three weft yarns starting from the vicinity of the fold. When two or fewer weft yarns are removed, the loop diameter becomes smaller, the insertable core yarn becomes thinner, and it may be impossible to maintain seam strength.
[0099] From the perspective of preventing seam marks, it is preferable to remove no more than 9 weft yarns starting from the vicinity of the fold. When more than 10 weft yarns are removed, the nap may not adhere well at the loop edge (loop root), and the nap may shed when used with the base fabric, resulting in seam marks.
[0100] In either Mode 1 or Mode 2, when the base fabric for the papermaking felt is a plain weave fabric, the number of weft yarns removed is preferably an odd number starting from the vicinity of the fold, and more preferably 3, 5, and 7 yarns starting from the vicinity of the fold. When the base fabric for the papermaking felt is a plain weave fabric and the number of weft yarns removed starting from the vicinity of the fold is an odd number, the proportion of warp yarns whose length in the mechanical direction (MD) relative to the CD axis is symmetrical can reach 100%. As a result, the apexes of all seam loops are located at the same height, and the apexes of the seam loops are continuous at fixed positions, forming extremely good seam loops that allow for smooth insertion of the core yarn.
[0101] In either Mode 1 or Mode 2, when the base fabric for the papermaking felt is a twill fabric, the number of weft yarns removed from near the fold is preferably 2, 3, 4, 6, 7, or 8, and more preferably 3, 4, 6, or 7. When the base fabric for the papermaking felt is a plain weave fabric and the number of weft yarns removed from near the fold is 2, 3, 4, 6, 7, or 8, the proportion of warp yarns with symmetrical warp loop lengths relative to the CD axis in the mechanical direction (MD) reaches 50%, making it easier to insert the core yarn.
[0102] Method 2 of the present invention includes: (c) a step of joining the ends of a papermaking felt base fabric together to form a joint.
[0103] The means of joining the ends of the base fabric for papermaking felt together can be as described in method 1 of the present invention.
[0104] In one embodiment, method 1 or 2 of the present invention further includes a step of substantially aligning at least one weft yarn on one side with the corresponding weft yarn on the other side near the location where the yarns are joined in a loop-forming manner.
[0105] The process includes folding the papermaking felt base fabric in such a way that at least one weft yarn on one side is aligned with the corresponding weft yarn on the other side near a predetermined position for forming a loop. This process is preferably performed after the folding process and before the process of forming a loop with a portion of the papermaking felt base fabric, and includes, for example, temporary fixing or temporary sewing in the transverse direction at intervals of 5 cm to 10 cm after the folding process. The means of temporary fixing or temporary sewing is not particularly limited, but a stapler is preferred from the viewpoint of preventing misalignment of the base fabric on one side and the other side when forming a loop. By doing so, at least one weft yarn on one side can be easily and reliably aligned with the corresponding weft yarn on the other side near the position for forming a loop.
[0106] The present invention also relates to a base fabric for papermaking blankets having seam rings obtained by method 1 or 2 of the present invention described above.
[0107] The present invention also relates to a papermaking blanket, wherein the substrate of the papermaking blanket comprises a papermaking blanket base fabric with seam rings obtained by method 1 or 2 of the present invention described above.
[0108] In one embodiment, the substrate of the papermaking felt of the present invention is composed of layers of base fabric. The papermaking felt, by having a substrate of layers of base fabric, has a high porosity and can be used in high-dehydration sections. In one embodiment, the base fabric for the papermaking felt with seam rings, obtained by method 1 or 2 of the present invention described above, is disposed on the outermost layer of the substrate of the papermaking felt.
[0109] In one embodiment, the substrate of the papermaking felt of the present invention consists of two layers: an outer layer and an inner layer. In another embodiment, the papermaking felt base fabric with seam rings obtained by method 1 or 2 of the present invention is disposed on the outer layer of the substrate of the papermaking felt.
[0110] The inner layer is manufactured by bending the papermaking blanket with a base fabric and joining the ends of the substrate together, and has a joint obtained by joining the ends of the substrate together.
[0111] The inner layer does not form a seam loop; the folded part of the inner layer is bonded to the base fabric of the outer layer at the position where it is joined in the manner of forming the loop of the outer layer.
[0112] The inner layer can be configured in the following ways: the inner layer having a joint after being joined with the outer layer is placed in the outer layer having a joint; or, the inner layer having a joint is configured before the process of folding the outer layer, and then the outer layer is folded in such a way that the inner layer is housed inside.
[0113] In this embodiment, the joint of the papermaking felt base fabric disposed on the outer layer of the substrate can be located on the wet paper side or the roll side. In one embodiment, the joint is located on the wet paper side. When the joint is located on the wet paper side, the joint is protected by the felt layer, and damage during pressing (dehydration of the wet paper) (such as cracking of the joint) is suppressed, thus maintaining the strength of the papermaking felt base fabric and even the papermaking felt itself. In another embodiment, the joint is located on the roll side. When the joint is located on the roll side, the surface smoothness of the wet paper side of the papermaking felt is maintained, preventing the seam marks of the joint from transferring to the wet paper.
[0114] In one embodiment, the base fabric for papermaking felt disposed in the inner layer of the substrate and the base fabric for papermaking felt with seam rings disposed in the outer layer of the substrate are of the same type, and have a joint obtained by joining the ends of the substrates together. In this case, the inner layer base fabric is bonded to the outer layer base fabric at the position where it is joined in a manner that forms a ring with the outer layer. By making the inner and outer layer base fabrics of the same type, papermaking felt consisting of two layers can be manufactured efficiently.
[0115] In this embodiment, the joint portions of the papermaking felt base fabric disposed on the outer layer of the substrate and the joint portions of the papermaking felt base fabric disposed on the inner layer of the substrate can be located on the wet paper side or the roll side, respectively. In one embodiment, one or more joint portions are located on the wet paper side. When one or more joint portions are located on the wet paper side, the joint portions are protected by the felt layer, damage during pressing (dehydration of wet paper) is suppressed, and the strength of the papermaking felt base fabric and even the papermaking felt itself can be maintained. In another embodiment, one or more joint portions are located on the roll side. When the joint portions are located on the roll side, the surface smoothness of the wet paper side of the papermaking felt is maintained, and the seam marks of the joint portions can be prevented from being transferred to the wet paper.
[0116] Example The following describes in detail the base fabric for papermaking blankets with seam rings according to the present invention through examples, but these examples do not constitute any limitation on the present invention.
[0117] Example of Method 1 of the present invention (1) The base fabric for papermaking blankets with seam rings of the manufacturing examples and comparative examples A 39.8m (MD) × 363cm (CD) dimension is cut from a raw fabric (original and reverse) woven from multiple warp and weft yarns as the base fabric for papermaking blankets. The base fabric is a plain weave fabric, using monofilaments composed of polyamide 6 (fineness: 1240dtex, 44 threads / 5cm) as warp yarns and monofilaments composed of polyamide 610 (fineness: 1000dtex, 44 threads / 5cm) as weft yarns.
[0118] (a) Base fabric for manufacturing papermaking blankets with seam rings, as a comparative example Two areas for making loops are pre-determined in the aforementioned base fabric, and all weft yarns in these areas are removed. Then, in each area, the base fabric is folded so that multiple warp yarns are aligned with themselves in the mechanical direction (MD), and the ends of the base fabric are joined together. In each area where the weft yarns have been removed, the base fabric on the wet paper side and the base fabric on the roll side are temporarily fixed together in the mechanical transverse direction (5cm interval) with a nail gun to form a seam loop. Along the position of the temporary fixation, a sewing machine (manufactured by JUKI, model: HZL-V2000) is used from the roll side to sew together using polyamide 6 yarn (two strands of polyamide 6 yarn twisted at 0.5 twists / cm (fineness: 588dtex) and two strands of polyamide 6 yarn twisted at 3.2 twists / cm (fineness: 1150dtex)) as the top thread and polyamide 6 monofilament yarn (fineness: 220dtex) as the bottom thread to obtain a base fabric for papermaking felt with a seam loop.
[0119] (b) Manufacturing the base fabric for papermaking blankets with seam rings according to the embodiment Two areas for creating loops are pre-defined in the aforementioned base fabric. In each area, the base fabric is folded so that multiple warp yarns are aligned with themselves in the mechanical direction (MD). The ends of the base fabric are then joined to form a joint. In each area, loops are formed by temporarily securing the fabric with a nail gun (5cm intervals). Along the temporary fixation points, a sewing machine (JUKI, model: HZL-V2000) is used from the side of the roller. Polyamide 6 yarn (a combination of two yarns twisted at 3.2 times / cm, with a Z-twist of 0.5 times / cm and a twist of 588 dtex) is used as the top thread, and polyamide 6 monofilament yarn (220 dtex) is used as the bottom thread for sewing. Then, the seven adjacent weft yarns in each loop are removed sequentially from near the fold, marking the seam loops to obtain a base fabric for papermaking felt with seam loops. In addition, by using the same process, the six adjacent weft yarns in each ring are removed sequentially from near the fold to define the seam rings, thus obtaining a base fabric for papermaking blankets with seam rings.
[0120] A comparison of the manufacturing methods of the papermaking blanket base fabric with seam rings in the comparative examples and embodiments is shown in Table 1.
[0121] Table 1 (2) Evaluation of the method for manufacturing the base fabric for papermaking blankets with seam rings in the comparative examples and embodiments In the manufacturing method of the papermaking blanket base fabric with seam ring described in the comparative example (1)(a) above, the removal of weft yarns in step 2 can be carried out smoothly, but after the base fabric is joined using a sewing machine in step 4, the arrangement of the warp yarns constituting the seam ring is deformed, and the seam ring collapses. Figure 3 The joint ring becomes unable to be connected or the core wire can be inserted. Even changing the temporary fixing interval of the nail gun to 1cm cannot make the joint ring stand up.
[0122] In the manufacturing method of the papermaking blanket base fabric with seam ring described in embodiments (1) and (b) above, at the time point when the base fabric is joined using a sewing machine in step 3, the alignment of the warp yarns constituting the ring does not deform; although the removal of the weft yarns in step 4 is slightly more time-consuming than the method in the comparative example, the alignment of the warp yarns constituting the seam ring does not deform after the weft yarns are removed, and the seam ring maintains a good shape regardless of the number of weft yarns removed. Figure 4 Among them, the seam loop when removing 7 weft yarns has a continuous center (apex) compared to the seam loop when removing 6 weft yarns, making it easier to insert the core yarn. Figure 5 ).
[0123] Example of Method 2 of the present invention (1) Manufacturing a base fabric for papermaking blankets with seam rings (a) The case of removing 7 weft yarns from a plain weave base fabric. A 39.8m (MD) × 363cm (CD) dimension is cut from a greige fabric woven from multiple warp and weft yarns to serve as the base fabric for papermaking blankets. The base fabric is a plain weave fabric, using monofilaments composed of polyamide 6 (fineness: 1240dtex, 44 threads / 5cm) as warp yarns and monofilaments composed of polyamide 610 (fineness: 1000dtex, 44 threads / 5cm) as weft yarns.
[0124] Two areas for creating loops are pre-defined in the aforementioned base fabric. In each area, the base fabric is folded so that multiple warp yarns are aligned with themselves in the mechanical direction (MD). The ends of the base fabric are then joined to form a joint. In each area, loops are formed by temporarily securing the fabric with a nail gun (5cm intervals). Along the temporary fixation points, a sewing machine (JUKI, model: HZL-V2000) is used from the side of the roller. Polyamide 6 yarn (a combination of two yarns twisted at 3.2 times / cm, with a Z-twist of 0.5 times / cm and a twist of 588 dtex) is used as the top thread, and polyamide 6 monofilament yarn (220 dtex) is used as the bottom thread for sewing. Then, the seven adjacent weft yarns in each loop are removed sequentially from near the fold, marking the seam loops to obtain a base fabric for papermaking felt with seam loops.
[0125] (b) Case where 7 weft yarns are removed from the twill base fabric A 39.8m (MD) × 363cm (CD) dimension is cut from a greige fabric woven with multiple warp and weft yarns to serve as the base fabric for papermaking blankets. The base fabric is a twill fabric (2 / 2 twill), using monofilaments composed of polyamide 6 (fineness: 1240dtex, 44 threads / 5cm) as warp yarns and monofilaments composed of polyamide 610 (fineness: 1000dtex, 44 threads / 5cm) as weft yarns.
[0126] Two areas for creating loops are pre-defined in the aforementioned base fabric. In each area, the base fabric is folded so that multiple warp yarns are aligned with themselves in the mechanical direction (MD). The ends of the base fabric are then joined to form a joint. In each area, loops are formed by temporarily securing the fabric with a nail gun (5cm intervals). Along the temporary fixation points, a sewing machine (JUKI, model: HZL-V2000) is used from the side of the roller. Polyamide 6 yarn (a combination of two yarns twisted at 3.2 times / cm, with a Z-twist of 0.5 times / cm and a twist of 588 dtex) is used as the top thread, and polyamide 6 monofilament yarn (220 dtex) is used as the bottom thread for sewing. Then, the seven adjacent weft yarns in each loop are removed sequentially from near the fold, marking the seam loops to obtain a base fabric for papermaking felt with seam loops.
[0127] (c) Case where 6 weft yarns are removed from the twill base fabric The same greige fabric as described in (b) above is used as the base fabric for papermaking felt. Following the same process as described in (b) above, the six adjacent weft yarns in each ring are removed sequentially from near the fold, and the seam rings are marked to obtain the base fabric for papermaking felt with seam rings.
[0128] (2) Evaluation of the manufacturing method of the base fabric for papermaking felt with seam rings In the method for manufacturing the base fabric for papermaking felt with seam rings in the embodiments described above (1)(a), the proportion of warp yarns whose length is symmetrical in the mechanical direction (MD) relative to the CD axis is 100%. Figure 6 In the manufacturing method described above, the arrangement of the warp yarns forming the seam loops does not deform after the weft yarns are removed, and the seam loops maintain a good shape. In particular, the apexes of all seam loops are at the same height, and the apexes of the seam loops are continuous at fixed positions, forming a shape that is extremely easy to insert the core yarn into. Figure 7 ).
[0129] In the method for manufacturing the base fabric for papermaking felt with seam rings in the embodiments described above (1) and (b), the proportion of warp yarns whose length is symmetrical in the mechanical direction (MD) relative to the CD axis is 50%. Figure 8 In the manufacturing method, after the weft yarn is removed, the arrangement of the warp yarns forming the seam loop does not deform, the seam loop maintains a good shape, and 50% of the apex of each seam loop is at the same height, forming a shape that facilitates the insertion of the core yarn. Figure 9 ).
[0130] In the method for manufacturing the base fabric for papermaking felt with seam rings in the embodiments described above (1) and (c), the proportion of warp yarns whose length is symmetrical in the mechanical direction (MD) relative to the CD axis is 50%. Figure 9 In the manufacturing method, after the weft yarn is removed, the arrangement of the warp yarns forming the seam loop does not deform, the seam loop maintains a good shape, and 50% of the apex of each seam loop is at the same height, forming a shape that facilitates the insertion of the core yarn. Figure 10 ).
[0131] Industrial availability By using the manufacturing method of the papermaking felt base fabric with seam ring of the present invention, it is possible to maintain a good shape of the seam ring and manufacture a papermaking felt base fabric with seam ring that is easy to insert core wire.
[0132] Explanation of reference numerals in the attached figures F: Papermaking blankets L: Seam ring B: Base fabric W: Hair layer S: Core wire
Claims
1. A method for manufacturing a base fabric for papermaking blankets with seam rings, comprising: A process for providing a base fabric for papermaking felt, the base fabric comprising a plurality of warp yarns extending in the mechanical direction MD and a plurality of weft yarns extending in the mechanical transverse direction CD interwoven with the plurality of warp yarns; The process of folding the papermaking blanket at any two points with the base fabric so that each of the multiple warp yarns is substantially aligned with itself on the MD. The process of joining the ends of the base fabric of the papermaking felt together to form a joint; Near each fold, the papermaking felt is joined with a portion of the base fabric in a loop-like manner; The process of removing the weft yarn within the ring from the base fabric for the papermaking felt to define the seam ring.
2. The method of claim 1, further comprising the step of: substantially aligning at least one weft yarn on one side with the corresponding weft yarn on the other side near the location where the yarns are joined in a loop-forming manner.
3. The method as described in claim 1 or 2, wherein, The base fabric for papermaking blankets is a plain weave fabric, and an odd number of weft yarns are removed.
4. The method according to any one of claims 1 to 3, wherein, The warp yarn is a monofilament.
5. The method as described in claim 4, wherein, The monofilament has a fineness of over 800 dtex.
6. The method according to any one of claims 1 to 5, wherein, The weft yarn is a monofilament.
7. The method of claim 6, wherein, The monofilament has a fineness of over 800 dtex.
8. A base fabric for papermaking blankets having a seam ring, obtained by the method according to any one of claims 1 to 7.
9. A papermaking blanket, the substrate of which comprises a papermaking blanket base fabric having a seam ring as described in claim 8.
10. The papermaking felt as described in claim 9, wherein, The base fabric for papermaking felt with seam rings as described in claim 8 is disposed on the outermost layer of the base material of the papermaking felt.
11. The papermaking felt as described in claim 9 or 10, wherein, The base material of the papermaking felt consists of two layers: an outer layer and an inner layer. The outer layer of the base material is provided with a papermaking felt base fabric having a seam ring as described in claim 8.
12. The papermaking felt as described in claim 11, wherein, The joint of the papermaking felt base fabric with a seam ring, which is disposed on the outer layer of the substrate, is located on the wet paper side.
13. The papermaking felt as described in claim 11, wherein, The joint of the papermaking felt base fabric with a seam ring, which is disposed on the outer layer of the substrate, is located on the roll side.
14. The papermaking felt as described in claim 11, wherein, The papermaking felt base fabric disposed in the inner layer of the substrate is of the same type as the papermaking felt base fabric with seam ring disposed in the outer layer of the substrate, and has a joint obtained by joining the ends of the base fabric together.
15. The papermaking felt as described in claim 14, wherein, One or more of the joint portions of the papermaking felt base fabric with seam ring disposed on the outer layer of the substrate and the joint portions of the papermaking felt base fabric disposed on the inner layer of the substrate are located on the wet paper side.
16. The papermaking felt as described in claim 14, wherein, One or more of the joint portions of the papermaking felt base fabric with seam ring disposed on the outer layer of the substrate and the joint portions of the papermaking felt base fabric disposed on the inner layer of the substrate are located on the roll side.
17. A method for manufacturing a base fabric for papermaking blankets having a seam ring, comprising: (a) A process of providing a base fabric for papermaking felt, the base fabric comprising a plurality of warp yarns extending in the mechanical direction MD and a plurality of weft yarns extending in the mechanical transverse direction CD interwoven with the plurality of warp yarns; (b) The process of forming a seam ring in the base fabric for papermaking felt; Process (b) includes: (1-1) The process of folding the papermaking blanket at any two points with the base fabric so that each of the multiple warp yarns is substantially aligned with itself on the MD. (1-2) The process of joining the papermaking felt with a portion of the base fabric in a loop near each fold; and (1-3) The process of removing the weft yarns in the ring from the base fabric for papermaking blankets to form a window and delineate the seam ring, wherein, by adjusting the number of weft yarns removed, the proportion of warp yarns with symmetrical lengths in the mechanical direction MD of the warp yarn ring relative to the CD axis of the seam ring reaches more than 50%, wherein the CD axis is an axis that connects the centers of the window in the mechanical direction along the mechanical transverse direction. or, (2-1) The process of removing the weft yarn at any two points of the base fabric for papermaking felt to define the window; (2-2) The process of folding the papermaking felt at each of the windows with a base fabric so that each of the multiple warp yarns is substantially aligned with itself on the MD; and (2-3) Near each fold, a part of the papermaking blanket is joined in a loop by forming a ring, wherein the number of weft yarns removed is adjusted so that the proportion of warp yarns with symmetrical length in the mechanical direction MD of the CD axis relative to the seam ring reaches more than 50%. (c) The process of joining the ends of the base fabric of the papermaking felt together to form a joint.
18. The method of claim 17, wherein, The number of weft yarns removed is 3 or more.
19. The method of claim 17 or 18, wherein, The number of weft yarns removed is 9 or less.
20. The method according to any one of claims 17 to 19, wherein, The base fabric for papermaking blankets is plain weave or twill weave.
21. The method of claim 20, wherein, The base fabric for papermaking blankets is a plain weave fabric, and the number of weft yarns removed is an odd number.
22. The method of claim 20, wherein, The base fabric for papermaking blankets is a twill weave, and the number of weft yarns removed is 3, 4, 6 or 7.
23. The method according to any one of claims 17 to 22, further comprising: The process of substantially aligning at least one weft yarn on one side with the corresponding weft yarn on the other side near the position where the yarns are joined in a loop-like manner.
24. The method according to any one of claims 17 to 23, wherein, The warp yarn is a monofilament.
25. The method of claim 24, wherein, The monofilament has a fineness of over 800 dtex.
26. The method according to any one of claims 17 to 25, wherein, The weft yarn is a monofilament.
27. The method of claim 26, wherein, The monofilament has a fineness of over 800 dtex.
28. A base fabric for papermaking blankets having a seam ring, obtained by the method according to any one of claims 17 to 27.
29. A papermaking blanket, the substrate of which comprises a papermaking blanket base fabric having a seam ring as described in claim 28.
30. The papermaking felt as described in claim 29, wherein, The papermaking felt base fabric with seam ring as described in claim 28 is disposed on the outermost layer of the papermaking felt substrate.
31. The papermaking felt as described in claim 29 or 30, wherein, The base material of the papermaking felt consists of two layers: an outer layer and an inner layer. The outer layer of the base material is provided with a papermaking felt base fabric having a seam ring as described in claim 28.
32. The papermaking felt as described in claim 31, wherein, The joint of the papermaking felt base fabric with a seam ring, which is disposed on the outer layer of the substrate, is located on the wet paper side.
33. The papermaking felt as described in claim 31, wherein, The joint of the papermaking felt base fabric with a seam ring, which is disposed on the outer layer of the substrate, is located on the roll side.
34. The papermaking felt as described in claim 31, wherein, The papermaking felt base fabric disposed in the inner layer of the substrate is the same type as the papermaking felt base fabric with seam ring disposed in the outer layer of the substrate, and has a joint obtained by joining the ends of the base fabric together.
35. The papermaking felt as described in claim 34, wherein, One or more of the joint portions of the papermaking felt base fabric with seam ring disposed on the outer layer of the substrate and the joint portions of the papermaking felt base fabric disposed on the inner layer of the substrate are located on the wet paper side.
36. The papermaking felt as described in claim 34, wherein, One or more of the joint portions of the papermaking felt base fabric with seam ring disposed on the outer layer of the substrate and the joint portions of the papermaking felt base fabric disposed on the inner layer of the substrate are located on the roll side.