Industrial Fabric

This application claims the benefit of, and priority to, U.S. application Ser. No. 18/094,107, filed on Jan. 6, 2023, which is a continuation of International Application No. PCT/JP2021/015441, filed on Apr. 14, 2021, which claims priority to Japanese Patent Application No. 2020-119213, filed on Jul. 10, 2020, the entire contents of which are incorporated by reference herein in their entirety.

The present invention relates to industrial fabrics used for paper machines.

In the related art, papermaking meshes made of warps and wefts have been widely used as industrial fabrics for paper machines. The properties required for papermaking meshes vary. For example, as an industrial fabric in consideration of surface smoothness, an industrial fabric has been devised. The industrial fabric includes: an upper surface side fabric including upper surface side warps and upper surface side wefts; and a lower surface side fabric including lower surface side warps and lower side wefts, wherein an upper surface side weave repeat is formed by an upper surface side warp texture consisting of a set of two warps in the upper surface side fabric, the set of two warps is a warp binding yarn having a function of binding the upper surface side fabric and the lower surface side fabric, and the warp binding yarn is woven with a lower surface side weft at the same part where lower surface side warps are interwoven with a lower surface side weft (see Patent Literature 1).

However, in the industrial two-layer fabric described above, since the two warp binding yarns have the same texture, the intersections are regularly arranged. Therefore, marks due to the intersections are more likely to be generated.

In this background, one of exemplary purposes of the present invention is to provide a new industrial fabric that suppresses the generation of marks.

An industrial fabric according to one embodiment of the present invention is an industrial fabric in which an upper surface side fabric composed of upper surface side warps and upper surface side wefts and a lower surface side fabric composed of lower surface side warps and lower surface side wefts are bound to each other, wherein a first warp that belongs to the upper surface side warps functions as an upper surface side binding yarn that binds the upper surface side fabric and the lower surface side fabric, a second warp that belongs to the lower surface side warps functions as a lower surface side binding yarn that binds the upper surface side fabric and the lower surface side fabric, the number of knuckles formed by the upper surface side binding yarn in the upper surface side fabric is larger than the number of knuckles formed by the lower surface side binding yarn in the upper surface side fabric, and the number of the lower surface side warps is twice the number of the upper surface side warps.

According to this embodiment, since the number of lower surface side warps is twice the number of upper surface side warps, the density of upper surface side warps becomes small, allowing more upper surface side wefts to be woven compared to the normal ratio of upper surface side warps to lower surface side warps (1:1). As a result, the paper material is more supportive, and the formation and retention of the paper are improved. Further, since the number of knuckles formed by the upper surface side binding yarn in the upper surface side fabric is different from the number of knuckles formed by the lower surface side binding yarn in the upper surface side fabric, the regularity in the alignment of the intersection of the two binding yarns is reduced. As a result, the occurrence of marks is suppressed.

The upper surface side binding yarn and the lower surface side binding yarn may be adjacent to each other.

The upper surface side fabric is woven by upper surface side binding yarns, lower surface side binding yarns, and the upper surface side wefts, and the upper surface side binding yarns and the lower surface side binding yarns may mutually complement the surface texture of the upper surface side fabric. In this way, the mutual complementation of the texture by the two warps improves the surface properties since the texture does not collapse even at the bound parts. Further, the upper surface side binding yarn and the lower surface side binding yarn may mutually complement the surface texture of the lower surface side fabric.

Another embodiment of the present invention also relates to an industrial fabric. This industrial fabric is an industrial fabric in which an upper surface side fabric composed of upper surface side warps and upper surface side wefts and a lower surface side fabric composed of lower surface side warps and lower surface side wefts are bound to each other, wherein a first warp that belongs to the upper surface side warps functions as an upper surface side collapsing yarn that is interwoven with the upper surface side wefts and collapses a part of the surface texture of the upper surface side fabric, a second warp that belongs to the lower surface side warps functions as a lower surface side binding yarn that binds the upper surface side fabric and the lower surface side fabric, the number of the lower surface side warps is twice the number of the upper surface side warps, the upper surface side collapsing yarn and the lower surface side binding yarn are adjacent to each other, the upper surface side fabric is woven with at least the upper surface side collapsing yarn, the lower surface side binding yarn, and the upper surface side wefts, and the upper surface side collapsing yarn and the lower surface side binding yarn mutually complement the surface texture of the upper surface side fabric.

According to this embodiment, since the number of lower surface side warps is twice the number of upper surface side warps, the density of upper surface side warps becomes small, allowing more upper surface side wefts to be woven compared to the normal ratio of upper surface side warps to lower surface side warps (1:1). As a result, the paper material is more supportive, and the formation and retention of the paper are improved. Further, by binding the upper surface side fabric and the lower surface side fabric using the lower surface side binding yarns, the number of intersecting parts is reduced compared to a case where the upper surface side fabric and the lower surface side fabric are bound using the upper surface side binding yarns, and high air permeability can thus be ensured. The mutual complementation of the texture by the upper surface side collapsing yarns and lower surface side binding yarns improves the surface properties since the texture does not collapse even at the bound parts.

The upper surface side collapsing yarn may account for one-third of the total number of warps, and the lower surface side binding yarn may account for one-third of the total number of warps.

The total number of the upper surface side warps may be 30 to 150 per inch.

The total number of the upper surface side wefts may be 20 to 150 per inch.

The surface texture of the upper surface side fabric may be a plain weave. This improves fiber supportability and surface smoothness.

The lower surface side warps may pass above four lower surface side wefts, pass under one lower surface side weft, pass above two lower surface side wefts, and pass under one lower surface side weft in sequence in the lower surface side fabric.

The lower surface side warps may not be binding yarns.

The lower surface side binding yarn may include a first lower surface side binding yarn and a second lower surface side binding yarn adjacent to respective side of the lower surface side warps. In the lower surface side warps, a part to be interwoven with a lower surface side weft along with the adjacent first lower surface side binding yarn, and a part to be interwoven with a lower surface side weft along with the adjacent second lower surface side binding yarn may be arranged in a zigzag pattern. As a result, unlike rib weaving, marks are less likely to occur.

A weave repeat may have 12 shafts of warps and 24 shafts of wefts.

Optional combinations of the aforementioned constituting elements, and implementations of the invention in the form of methods, apparatuses, and systems may also be practiced as additional modes of the present invention.

According to the present invention, the generation of marks can be suppressed.

Hereinafter, the present invention will be explained based on embodiments with reference to the drawings. The same or equivalent constituting elements, members, and processes illustrated in each drawing shall be denoted by the same reference numerals, and duplicative explanations will be omitted appropriately. Further, the embodiments do not limit the invention and are shown for illustrative purposes, and not all the features described in the embodiments and combinations thereof are necessarily essential to the invention. Terms like “first”, “second”, etc., used in the specification and the claims do not indicate an order or importance by any means unless specified otherwise and are used to distinguish a certain feature from the others.

In the following explanation, “warps” are threads extending along the direction of web conveyance when a multi-layered fabric for papermaking is a looped belt, and “wefts” are threads extending in a direction that intersects the warps. The “upper surface side fabric” is a fabric located on the front surface side where the web is conveyed out of the two sides of a papermaking mesh when a multi-layered fabric is used as the papermaking mesh, and the “lower side fabric” is a fabric located mainly on the back side where a drive roller is in contact out of the two sides of a papermaking belt. The “surface” simply means a surface on the side where the upper surface side fabric or the lower surface side fabric is exposed. While the “surface” of the upper surface side fabric corresponds to the front surface side of a papermaking mesh, the “surface” of the lower surface side fabric corresponds to the back surface side of the papermaking mesh.

Further, “design diagram” represents the minimum repeating unit of a fabric texture and corresponds to a weave repeat of the fabric. In other words, “weave repeat” is repeated from front to back and left to right to form a “fabric”. Further, “knuckle” refers to a part where a warp protrudes on the surface by passing over or under a single or multiple wefts.

Further, “binding yarns” means at least some of warps that make up the upper surface side fabric (or lower surface side fabric) and are yarns that bind the upper surface side fabric with the lower surface side fabric by the weaving of a weft of the lower surface side fabric (or the upper surface side fabric) from the back surface side (or the front surface side) with a warp that should normally be woven with only a weft of the upper surface side fabric (or the lower surface side fabric).

The following is an explanation of the configuration of a multi-layered fabric for papermaking according to the first embodiment with reference to the drawings.is a design diagram showing a weave repeat of the multi-layered fabric for papermaking according to the first embodiment.is a cross-sectional view along each warp in the design diagram shown in.

In the design diagrams, warps are represented by Arabic numerals, for example, 1, 2, 3, and so on. Wefts are represented by Arabic numerals with a dash, for example, 1′, 2′, 3′, and so on. Upper surface side yarns are denoted by numbers with “U”, and lower surface side yarns are denoted by numbers with “L”, e.g., 1′U, 2′L, etc. Binding yarns that are binding the upper surface side fabric and the lower surface side fabric are denoted by numbers with “b”.

In the design diagrams, ▴ marks indicate that yarns that are to constitute lower surface side warps originally are placed above upper surface side wefts, x marks indicate that upper surface side warps are placed above upper surface side wefts, Δ marks indicate that yarns that are supposed to constitute upper surface side warps originally are placed below lower surface side wefts, and ∘ marks indicate that lower surface side warps are placed under lower surface side wefts.

In an industrial fabricaccording to the first embodiment shown in, an upper surface side fabric composed of upper surface side warps (Ub,Ub,Ub,Ub) and upper surface side wefts (′U to′U) and a lower surface side fabric composed of lower surface side warps (Lb,L,Lb,L, . . . ,L) and lower surface side wefts (′L,′ L, . . . ,′L) are joined to each other.

The weaving method of each warp and each weft in the industrial fabricwill be explained next with reference to. The upper surface side warpUb functions as an upper surface side binding yarn that binds the upper surface side fabric and the lower surface side fabric. The upper surface side warpUb is woven in such a manner that the upper surface side warpUb passes above the upper surface side weft′U to form a front surface side knuckle, then passes between the upper surface side wefts′U to′U and the lower surface side weft′L and then passes under the lower surface side weft′L to form a back surface side knuckle, then passes between the upper surface side wefts′U to′U and the upper surface side weft′L and then passes above the upper surface side weft′L to form a front surface side knuckle, then passes under the upper surface side weft′U and then passes above the upper surface side weft′U to form a front surface side knuckle, . . . , then passes under the upper surface side weft′U and then passes above the upper surface side weft′U to form a front surface side knuckle, and then passes under the upper surface side weft′U.

The lower surface side warpLb is adjacent to the upper surface side warpUb and functions as a lower surface side binding yarn that binds the upper surface side fabric and the lower surface side fabric. The lower surface side warpLb is woven in such a manner that the lower surface side warpLb passes between the upper surface side wefts′U to′U and the lower surface side weft′L and then passes above the upper surface side weft′U to form a front surface side knuckle, next passes under the upper surface side weft′U and then passes above the upper surface side weft′U to form a front surface side knuckle, then passes under the upper surface side weft′U and then passes above the upper surface side weft′U to form a front surface side knuckle, then passes between the upper surface side wefts′U to′U and the lower surface side weft′L and then passes under the lower surface side weft′L to form a back surface side knuckle, and then passes between the upper surface side wefts′U to′U and the lower surface side wefts′L and′L.

The lower surface side warpL is woven in such a manner that the lower surface side warpL passes under the lower surface side weft′L to form a back surface side knuckle, then passes between the upper surface side wefts′U to′U and the lower surface side wefts′L,′L,′L, and′L and passes under the lower surface side weft′L to form a back surface side knuckle, and then passes between the upper surface side wefts′U to′U and the lower surface side wefts′L and′L.

The upper surface side warpUb that functions as an upper surface side binding yarn is woven in such a manner that the upper surface side warpUb passes below the lower surface side weft′L to form a back surface side knuckle, then passes between the upper surface side wefts′U to′U and the lower surface side weft′L and then passes above the upper surface side weft′U to form a front surface side knuckle, next passes between the upper surface side weft′U and the lower surface side weft′L and then passes above the upper surface side weft′U to form a front surface side knuckle, . . . , then passes between the upper surface side weft′U and the lower surface side weft′L and then passes above the upper surface side wefts′U to′U to form a front surface side knuckle, and then passes between the upper surface side wefts′U to′U and the lower surface side wefts′L and′L.

The lower surface side warpLb that functions as a lower surface side binding yarn is adjacent to the upper surface side warpUb and is woven in such a manner that the lower surface side warpLb passes between the upper surface side weft′U and the lower surface side weft′L and passes above the upper surface side weft′U to form a front surface side knuckle, then passes between the upper surface side wefts′U to′U and the lower surface side wefts′L and′L and passes under the lower surface side weft′L to form a back surface side knuckle, then passes between the upper surface side wefts′U to′U and the lower surface side wefts′L,′L, and′L and then passes above the upper surface side weft′U to form a front surface side knuckle, then passes between the upper surface side weft′U and the lower surface side weft′L, and then passes above the upper surface side weft′U to form a front surface side knuckle.

The lower surface side warpL is woven in such a manner that the lower surface side warpL passes between the upper surface side wefts′U to′U and the lower surface side wefts′L,′L, and′L and then passes under the lower surface side weft′L to form a back surface side knuckle, then passes between the upper surface side wefts′U to′U and the lower surface side wefts′L and′L and then passes under the lower surface side weft′L to form a back surface side knuckle, and then passes between the upper surface side wefts′U to′U and the lower surface side weft′L.

When compared, the upper surface side warpsUb andUb and the lower surface side warpsLb,L,Lb, andL shown inare woven in the same way as the upper surface side warpsUb andUb and the lower surface side warpsLb,L,Lb, andL described above except that the warps are shifted by eight upper surface side wefts in the transport direction. Thus, the explanation of the weaving method thereof will be omitted.

As described, in the industrial fabricaccording to the present embodiment, the weave repeat shown inis formed in a state where an upper surface side fabric composed of upper surface side warps (Ub,Ub,Ub,Ub) and upper surface side wefts (′U to′U) and a lower surface side fabric composed of lower surface side warps (Lb,L,Lb,L, . . . ,L) and lower surface side wefts (′L,′ L, . . . ,′L) are joined to each other.

Further, the industrial fabrichas a total of 12 shafts of upper surface side warps (Ub,Ub,Ub,Ub) and lower surface side warps (Lb,L,Lb,L, . . . ,L) and a total of 24 shafts of upper surface side wefts (′U to′U) and lower side wefts (′L,′L, . . . ,′L). Thereby, the industrial fabricexhibits good smoothness compared to, for example, a case of a 48-shaft weft weave repeat since the force by which the upper surface side wefts on which the binding yarns are applied is pulled toward the lower surface side works evenly. Further, in the industrial fabric, since the number of times the binding yarns go up and down becomes larger and the number of binding points is increased compared to those in a case of a 48-shaft weft weave repeat, the binding force becomes strong, thus suppressing internal wear.

Further, since the number of lower surface side warps (which is eight) is twice the number of upper surface side warps (which is four), the industrial fabrichas a smaller density of upper surface side warps, allowing more upper surface side wefts to be woven compared to the normal ratio of upper surface side warps to lower surface side warps (:). As a result, the paper material is more supportive, and the formation and retention of the paper are improved.

Further, the space ratio (gap between warps) of the upper surface side warps increases, and the space ratio of the lower surface side warps decreases. As a result, during dewatering of the material, the flow velocity on the front side of the industrial fabricbecomes smaller and the flow velocity on the back side becomes larger, resulting in slow dewatering and improved paper formation. If there is a large amount of water retained inside the mesh, the high-speed rotation of the paper machine causes a phenomenon called splash where water scatters in the form of mist. However, since the surface tension of water on the front surface side is lowered and less water is thus held inside the mesh, the industrial fabricaccording to the present embodiment can suppress the occurrence of splash.

In the industrial fabricaccording to the present embodiment, the number of knuckles (which is five) formed by the upper surface side warpUb (Ub,Ub,Ub) serving as an upper surface side binding yarn in the upper surface side fabric is different from the number of knuckles (which is three) formed by the lower surface side warpLb (Lb,Lb,Lb) serving as a lower surface side binding yarn in the upper surface side fabric. Thus, in the industrial fabric, the texture of the upper surface side binding yarn and the texture of the lower side binding yarn are different from each other.

In general, the intersection of two binding yarns tends to have (i) decreased dewaterability and (ii) locally increased draw-in of the upper surface side weft. Therefore, when the intersections are regularly aligned, marks (weft marks, regular diagonal marks) are more likely to occur in those areas. In particular, when the binding yarns have the same texture, the above defects are likely to be caused due to the occurrence of the regularity. Therefore, making the two binding yarns to have different texture as in the industrial fabricreduces the regularity in the alignment of the intersection of the two binding yarns. As a result, the occurrence of marks is suppressed. Further, smoothness and uniform dewaterability are improved, and the formation of the paper is enhanced.

Further, the upper surface side fabric of the industrial fabricis woven by the upper surface side warps (Ub,Ub,Ub,Ub) serving as upper surface side binding yarns, the lower surface side warps (Lb,Lb,Lb,Lb) serving as lower surface side binding yarns, and the upper surface side wefts (′U to′U), and the upper surface side binding yarns and the lower surface side binding yarns mutually complement the surface texture of the upper surface side fabric. In this way, the mutual complementation of the texture by the two warps improves the surface properties since the texture does not collapse even at the bound parts. Further, the upper surface side binding yarn and the lower surface side binding yarn mutually complement the surface texture of the lower surface side fabric. Also, in the industrial fabricaccording to the present embodiment, the surface texture of the upper surface side fabric is a plain weave. This improves fiber supportability and surface smoothness.

Next, an explanation will be given of internal wear inside a papermaking mesh of a multi-layered fabric. In general, if the binding force between an upper mesh (upper surface side fabric) and a lower mesh (lower surface side fabric) is weak, the high speed rotation of a paper machine may cause the upper mesh and the lower mesh to rub against each other, resulting in internal wear of the mesh. When such internal wear occurs, the dewaterability and strength of the mesh decreases, and stable papermaking is thus hindered. Therefore, in the industrial fabricaccording to the present embodiment, warps that are interwoven only in upper surface side wefts are eliminated, and two thirds of all warps are composed of binding yarns. In this manner, by preventing the presence of warps interwoven only in the upper surface side wefts and increasing the number of binding yarns, the binding force between the upper and lower surface side fabrics can be increased, and internal wear can be suppressed.

Next, an explanation will be given of the texture of the back surface side (surface texture of the lower surface side fabric) of the industrial fabricaccording to the present embodiment. For example, in the industrial fabric, since a single lower surface side weft′L is woven with two warps, the lower surface side warpLb and the lower surface side warpL, the space between knuckles of the lower surface side weft is larger than that in a texture where one lower surface side weft is woven with one warp. Since wear on the machine surface side is mainly caused in the lower surface side weft, large knuckles of the lower surface side weft improve the life associated with wear.

Further, the lower surface side fabric of the industrial fabricis woven such that lower surface side warps not serving as binding yarns (L,L,L,L) pass over four lower surface side wefts, pass under one lower surface side weft, pass over two lower surface side weft, and then pass under one lower surface side weft in sequence. For example, in the lower surface side warpL, a part to be interwoven with the lower surface side weft′L along with the lower surface side warpLb, which is an adjacent lower surface side binding yarn, and a part to be interwoven with the lower surface side weft′L along with the upper surface side warpU, which is an adjacent upper surface side binding yarn, are arranged in a zigzag pattern. The same applies to the other lower surface side warps (L,L,L). As a result, unlike rib weaving, marks are less likely to occur.

is a design diagram showing a weave repeat of a multi-layered fabric for papermaking according to the second embodiment.is a cross-sectional view along each warp in the design diagram shown in. The signs and marks in each figure are the same as those in the first embodiment, and explanations thereof will be appropriately omitted.

In an industrial fabricaccording to the second embodiment shown in, an upper surface side fabric composed of upper surface side warps (U,U,U,U) and upper surface side wefts (′U to′U) and a lower surface side fabric composed of lower surface side warps (Lb,L,Lb,L, . . . ,L) and lower surface side wefts (′L,′L, . . . ,′L) are joined to each other.

The weaving method of each warp and each weft in the industrial fabricwill be explained next with reference to. The upper surface side warpU is woven in such a manner that the upper surface side warpU passes between the upper surface side weft′U and the lower surface side weft′L and passes above the upper surface side weft′U to form a front surface side knuckle, then passes between the upper surface side weft′U and the lower surface side weft′L and then passes above the upper surface side weft′U to form a front surface side knuckle, . . . , then passes between the upper surface side weft′U and the lower surface side weft′L and then passes above the upper surface side weft′U to form a front surface side knuckle, and then passes between the upper surface side wefts′U and′U and the lower surface side weft′L.

The lower surface side warpLb is adjacent to the upper surface side warpU and functions as a lower surface side binding yarn that binds the upper surface side fabric and the lower surface side fabric. The lower surface side warpLb is woven in such a manner that the lower surface side warpLb passes between the upper surface side wefts′U to′U and the lower surface side wefts′L and′L and passes under the lower surface side weft′L to form a back surface side knuckle, then passes between the upper surface side wefts′U to′U and the lower surface side wefts′L and′L and then under the lower surface side weft′L to form a back surface side knuckle, and then passes between the upper surface side wefts′U to′U and the lower surface side wefts′L and′L and then above the upper surface side weft′U to form a front surface side knuckle.