How to repair mesh sheets for construction work

Abstract

To provide a method for easily repairing a mesh sheet for a construction work.SOLUTION: In a repair method, a repair sheet is laminated to cover a damaged portion of a mesh sheet for a construction work, and the repair sheet and the mesh sheet for a construction work are bonded together by applying a high-frequency welder. The mesh sheet for a construction work is a fabric using multifilament yarns containing core-sheath type composite filaments whose core component is a polyethylene terephthalate-based polymer and whose sheath component is a copolyester with a lower melting point than that of the polyethylene terephthalate-based polymer, as the weft. The repair sheet is made by integrally laminating a vinyl chloride resin layer on a surface of a fabric whose warp and weft are yarns made of a polyethylene terephthalate-based polymer. As the vinyl chloride resin is heated and melted by the high-frequency welder and only the sheath component is softened or melted, the mesh sheet for a construction work and the repair sheet are firmly bonded.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for easily repairing damaged portions of a mesh sheet for construction work. [Background technology]

[0002] Conventionally, when mesh sheets for construction work are damaged, such as torn or ripped, they are repaired by sewing with a sewing machine. However, mesh sheets for construction work are generally several meters in length and width, making sewing with a sewing machine difficult. For example, if a damaged area occurs in the center of a mesh sheet for construction work, it is difficult to reach the damaged area with a sewing needle, making sewing difficult. For this reason, Patent Document 1 proposes the following method for repairing mesh sheets for construction work. Specifically, the proposed method involves layering a mesh sheet of the same type as the mesh sheet for construction work over the damaged area of ​​the mesh sheet for construction work, via a mesh-like or nonwoven fabric-like low-melting-point polyester resin sheet, and then melting the low-melting-point polyester resin to fuse and bond the mesh sheet of the same type as the mesh sheet for construction work.

[0003] The low-melting polyester resin sheet used in this repair method melts completely during repair and flows along the warp or weft of the construction mesh sheet. Therefore, it is said that the mesh of the construction mesh sheet is not blocked and the original breathability can be maintained (Patent Document 1, paragraph 0018). However, because the low-melting polyester resin sheet melts completely, a mesh sheet of the same type as the construction mesh sheet is always required. Therefore, it has been difficult to procure the same type of mesh sheet, making emergency repairs at construction sites impossible.

[0004] Therefore, the present applicant proposed a method described in Patent Document 2 as a method for easily repairing mesh sheets for construction work. That is, the applicant proposed a repair method in which a damaged portion of a mesh sheet for construction work made of a woven fabric using multifilament yarns containing, as at least the weft yarns, a core-sheath type composite filament whose core component is a polyethylene terephthalate polymer and whose sheath component is a low-melting point copolymer polyester is covered with the same kind of heat-sensitive adhesive fabric, that is, a heat-sensitive adhesive fabric woven with heat-sensitive adhesive multifilament yarns formed by bundling core-sheath type composite filaments whose core component is a polyethylene terephthalate polymer and whose sheath component is a low-melting point copolymer polyester, and then applying heat and pressure to bond the mesh sheet for construction work to the heat-sensitive adhesive fabric.

[0005] [Patent Document 1] Japanese Patent Application Publication No. 5-141100 [Patent Document 2] Patent Application No. 2021-136748 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0006] An object of the present invention, similar to Patent Document 2, is to provide a method for easily repairing mesh sheets for construction work. [Means for solving the problem]

[0007] The present invention solves the above problem by using a type of so-called tarpaulin instead of the heat-sensitive adhesive fabric described in Patent Document 2. Specifically, the present invention relates to a method for repairing a damaged portion of a mesh sheet for construction work made of a woven fabric using multifilament yarns containing, as at least the weft yarns, core-sheath composite filaments whose core component is a polyethylene terephthalate polymer and whose sheath component is a copolymer polyester having a melting point lower than that of the polyethylene terephthalate polymer, the method comprising: preparing a repair sheet having a vinyl chloride resin layer laminated and integrated onto at least the surface of a woven fabric having yarns made of polyethylene terephthalate polymer as warp and weft yarns;

[0008] The construction mesh sheet used in the present invention is a fabric woven using warp and weft yarns. At least the weft yarns of this fabric are multifilament yarns containing a core-sheath composite filament whose core component is a polyethylene terephthalate polymer and whose sheath component is a copolymer polyester. Specifically, it is preferable to use a multifilament yarn formed by bundling a plurality of core-sheath composite filaments. The fineness of this core-sheath composite filament is about 5 to 15 decitex, and the number of fibers in the bundle is about 100 to 500. The multifilament yarn may or may not be twisted, and if twisted, the number of twists is about 50 to 200 times / m. The total fineness of the multifilament yarn is about 500 to 10,000 decitex.

[0009] The core-sheath composite filament has a core component made of a polyethylene terephthalate polymer and a sheath component made of a copolymer polyester having a lower melting point than the polyethylene terephthalate polymer. The melting point of the polyethylene terephthalate polymer is about 255°C, and the melting point of the copolymer polyester is about 120 to 190°C.

[0010] On the other hand, conventionally known warp yarns can be used. Specifically, it is preferable to use multifilament yarns formed by bundling a plurality of single-phase filaments made of polyethylene terephthalate polymers. Polyethylene terephthalate polymers have excellent weather resistance and are suitable for use in construction sheets. The fineness of the single-phase filaments is approximately 5 to 15 decitex, and the number of filaments in the bundle is approximately 100 to 500. The multifilament yarns may or may not be twisted, and if twisted, the number of twists is approximately 50 to 200 times / m. The total fineness of the multifilament yarns is approximately 500 to 5,000 decitex. The same multifilament yarns as those used for the weft yarns described above may also be used for the warp yarns.

[0011] Any conventionally known weave structure can be used for the woven fabric. In the present invention, it is particularly preferable to use a pongee weave fabric, which has excellent breathability and is less likely to cause unevenness. Here, a pongee weave fabric is a weave structure unit consisting of three or more wefts and two warps, with a plain weave structure at the intersections of the wefts and warps, and two warps interwoven at the exits of the three or more wefts. A specific example of a pongee weave fabric with three wefts is shown in FIG. 1. The structure enclosed by an oval in FIG. 1 is weave structure unit 1. Using this weave structure unit 1, the intersections of wefts 2a, 2b, and 2c and warps 3a and 3b form a plain weave structure, and warps 3a and 3b interwoven at the exits where they do not intersect with wefts 2a, 2b, and 2c (exits in the direction woven into the plain weave). A woven fabric with a ro weave is one in which this weave structure unit 1 is continuous from side to side and from top to bottom. As can be seen from Figure 1, gaps 4 are created when the interwoven warp threads 3a and 3b are continuous from side to side, resulting in a mesh sheet for construction work with good ventilation. In addition to fabrics with three weft threads, fabrics with five or seven weft threads are also common.

[0012] In the present invention, since a multifilament yarn containing a sheath-core composite filament is used as the weft of the woven fabric, the woven fabric may be heat-treated by the following method to make it less susceptible to misalignment or to impart rigidity in the weft direction. That is, the woven fabric is heat-treated at a temperature at which only the sheath component of the sheath-core composite filament softens or melts, melting and solidifying the sheath component to fuse the sheath-core composite filaments together and to fuse the intersections of the weft and warp. This imparts rigidity to the weft, making it rigid in the weft direction, and since the weft and warp are fused together, it is less likely to cause misalignment.

[0013] Mesh sheets for construction work are preferably flame-retardant to prevent the risk of fire at construction sites. To make mesh sheets for construction work flame-retardant, a flame-retardant resin can be used as a raw material. For example, polyethylene terephthalate polymers and / or copolymer polyesters can be made flame-retardant. Specifically, a flame retardant can be mixed into the polymer, or a flame-retardant compound such as a phosphorus compound can be copolymerized into the polymer molecule.

[0014] Next, the repair sheet prepared in the present invention will be described. This repair sheet is formed by laminating a vinyl chloride resin layer integrally onto at least the surface of a woven fabric. This woven fabric is woven in a conventionally known weave using yarns made of polyethylene terephthalate polymer as warp and weft. Yarns made of polyethylene terephthalate polymer have excellent weather resistance and are suitable for use as repair sheets for mesh sheets used outdoors in construction work. Furthermore, this yarn is preferably a multifilament yarn with excellent physical properties such as strength and elongation. The yarn fineness is optional, but is generally about 500 to 700 decitex. The simplest weave of the woven fabric is preferred, with a coarse plain weave being particularly preferred as it is less likely to impair breathability. Specifically, both the warp density and weft density are preferably 20 to 30 threads per inch.

[0015] A vinyl chloride resin layer is laminated and integrated onto at least the surface, preferably both surfaces, of the woven fabric. Vinyl chloride resin generates heat when dielectrically heated using a high-frequency welder and is easily melted. When melted, it reaches a temperature of approximately 170°C, softening or melting only the sheath component of the multifilament yarn used in the construction mesh sheet, thereby bonding the construction mesh sheet to the repair sheet. Therefore, vinyl chloride resin is suitable for use in the present invention.

[0016] The vinyl chloride resin layer is laminated and integrated with the woven fabric in a state where it covers the warp and weft of the woven fabric. The amount of the vinyl chloride resin layer is 300 to 500 g / m 2 This amount is enough to firmly bond the construction mesh sheet and the repair sheet together.

[0017] The method for repairing a construction mesh sheet according to the present invention allows repair using only the repair sheet. Specifically, by covering a damaged portion of the construction mesh sheet with the repair sheet and then subjecting the sheet to a high-frequency welder, the vinyl chloride resin layer of the repair sheet heats up and melts, while the sheath component of the multifilament yarn constituting the construction mesh sheet softens or melts, bonding the repair sheet to the construction mesh sheet. Thus, the damaged portion is repaired by the repair sheet. Furthermore, if a mesh sheet of the same type as the damaged construction mesh sheet is available, it can also be used for repair. That is, the damaged portion of the construction mesh sheet is covered with the repair sheet, and then a piece of the same mesh sheet, cut appropriately, is layered on top of the repair sheet and then subjected to a high-frequency welder. This causes the vinyl chloride resin layer of the repair sheet to heat up and melt, bonding the construction mesh sheet, the repair sheet, and the piece of the same mesh sheet together. Thus, the damaged portion is repaired by the repair sheet and the same mesh sheet.

[0018] The method for repairing mesh sheets for construction work according to the present invention can be easily carried out anytime and anywhere as long as high-frequency welder equipment is available. [Effects of the Invention]

[0019] The construction mesh sheet used in the present invention uses, as the weft, a multifilament yarn containing a core-sheath composite filament whose core component is a polyethylene terephthalate polymer and whose sheath component is a copolymer polyester. The repair sheet used in the present invention is formed by laminating a vinyl chloride resin layer onto a woven fabric whose warp and weft are made of polyethylene terephthalate polymer yarns. The repair method of the present invention involves covering the damaged portion of the construction mesh sheet with the repair sheet and applying it to a high-frequency welder, which generates heat and melts the vinyl chloride resin while softening or melting only the sheath component of the multifilament yarn that makes up the construction mesh sheet. This effectively achieves strong adhesion between the construction mesh sheet and the repair sheet. [Example]

[0020] [Mesh sheet for construction work 1] (Preparing the weft) Two bundles of 192 8.7-dtex core-sheath composite filaments (core / sheath mass ratio: core = 2.7 / sheath = 1.0) were twisted together at 80 twists / m to form a twisted yarn. The flame-retardant polyethylene terephthalate polymer was prepared by copolymerizing polyethylene terephthalate with a phosphorus compound in an amount of 1% by mass or less. The core filament was a flame-retardant polyethylene terephthalate polymer (melting point: 255°C) and the sheath filament was a crystalline copolymer polyester (melting point: 160°C).

[0021] (Preparing the warp threads) The warp yarn was prepared by bundling 140 single-phase filaments with a fineness of 13 decitex made of flame-retardant polyethylene terephthalate polymer (melting point 255°C) and twisting them at a twist rate of 80 times per meter. The flame-retardant polyethylene terephthalate polymer was prepared by copolymerizing polyethylene terephthalate with a phosphorus compound in an amount of 1% by mass or less.

[0022] The prepared weft and warp yarns were woven in the weave structure shown in Figure 1 to obtain a three-strand woven fabric. This fabric was heat-treated at 170°C for 43 seconds to obtain mesh sheet 1 for construction work. This mesh sheet 1 for construction work had a warp density of 25.4 threads / inch and a weft density of 12.7 threads / inch. In addition, only the sheath component of the weft yarn melted and solidified, forming a heat-fused multifilament yarn in which the core-sheath composite filaments were integrated with each other and fused to the warp yarns at their intersections.

[0023] [Mesh sheet for construction work 2] (Preparing the weft) A bundle of 192 8.7 dtex core-sheath composite filaments (core / sheath mass ratio: core = 2.7 / sheath = 1.0) with a core made of a flame-retardant polyethylene terephthalate polymer (melting point: 255°C) and a sheath made of a crystalline copolyester (melting point: 160°C) was twisted together with a bundle of 140 7.1 dtex polyethylene terephthalate filaments at a twist rate of 80 times per meter to form a twisted yarn. This twisted yarn was used as a weft. The flame-retardant polyethylene terephthalate polymer was the same as that used to obtain the mesh sheet 1 for construction work. (Preparing the warp threads) The same warp threads as those used to obtain mesh sheet 1 for construction work were prepared.

[0024] The prepared weft and warp yarns were woven in the weave structure shown in Figure 1 to obtain a three-strand woven fabric. This fabric was heat-treated at 170°C for 43 seconds to obtain mesh sheet 2 for construction work. This mesh sheet 2 for construction work had a warp density of 25.4 threads / inch and a weft density of 14.4 threads / inch. The sheath component of the weft yarns was melted and solidified to form heat-fused multifilament yarns in which the core-sheath composite filaments were integrated with each other and between the core-sheath composite filaments and the polyethylene terephthalate filaments, and the weft yarns were fused with the warp yarns at their intersections.

[0025] [Mesh sheet for construction work 3] (Preparing the weft) The weft yarn used to obtain the construction mesh sheet 2 was used as the first twisted yarn. A bundle of 140 polyethylene terephthalate filaments with a fineness of 13 decitex was twisted together at a twist rate of 80 times per meter to form the second twisted yarn. The first twisted yarn and the second twisted yarn were used as the weft yarn. (Preparing the warp threads) The same warp threads as those used to obtain mesh sheet 1 for construction work were prepared.

[0026] The prepared weft and warp yarns were woven in the weave structure shown in Figure 1 to obtain a three-strand georgette fabric. In this case, the second twisted yarn was used as the weft yarns 2a and 2c, and the first twisted yarn was used as the weft yarn 2b. This fabric was heat-treated at 190°C for 43 seconds to obtain a mesh sheet 3 for construction work. This mesh sheet 3 for construction work had a warp density of 25.4 threads / inch and a weft density of 17.8 threads / inch. Furthermore, the sheath component of the weft yarn 2b melted and solidified, forming a heat-fused multifilament yarn in which the core-sheath composite filaments were integrated with each other, and the weft yarn 2b was fused to the weft yarns 2a and 2c and further fused to the warp yarns at their intersections.

[0027] [Mesh sheet for construction work 4] (Preparing the weft) The weft yarn was made by twisting a bundle of 140 polyethylene terephthalate filaments with a fineness of 13 decitex at a twist count of 80 times per meter. (Preparing the warp threads) The same warp threads as those used to obtain mesh sheet 1 for construction work were prepared.

[0028] The prepared weft and warp yarns were used to weave the weave structure shown in Figure 1 to obtain a three-strand woven fabric. This fabric was heat-treated at 190°C for 43 seconds to obtain a mesh sheet 4 for construction work. This mesh sheet 4 for construction work had a warp density of 25.4 threads / inch and a weft density of 17.8 threads / inch. Both the warp and weft yarns were single-phase filament multifilament yarns made of polyethylene terephthalate polymer, and no fusion occurred between the filaments or between the warp and weft yarns.

[0029] Example 1 [Preparing repair sheets] An untwisted multifilament yarn consisting of 48 polyethylene terephthalate filaments with a fineness of 12.7 decitex was prepared as the warp yarn. On the other hand, a bundle of 48 polyethylene terephthalate filaments with a fineness of 12.7 decitex was twisted together at a twist count of 100 times per meter to prepare a twisted yarn as the weft yarn. This was then woven at a warp density of 24 threads per inch and a weft density of 22 threads per inch to produce a fabric with a basis weight of 122 g / m. 2 This plain weave fabric was coated with vinyl chloride resin to produce a fabric with a basis weight of 545 g / m 2 I got a repair sheet.

[0030] Test pieces measuring 30 mm wide and 350 mm long were taken from the construction mesh sheet 1. Two types of test pieces were taken from the construction mesh sheet 1: test piece A, in which the warp threads run longitudinally, and test piece B, in which the weft threads run longitudinally. Meanwhile, test pieces measuring 30 mm wide and 350 mm long were taken from the repair sheet. Test piece A and the repair sheet test piece were overlapped, leaving a 150 mm unbonded section in the longitudinal direction, and then put through a high-frequency welder (manufactured by Quinlite Electronics Co., Ltd.) to create 15 test pieces A with a 30 mm wide x 200 mm bonded section. Using test piece B, 15 test pieces B were created in the same manner as above. The high-frequency welder was used under the following conditions: output 4 kW, transmission time 10 seconds, and cooling time 3 seconds.

[0031] For 15 specimens A and 15 specimens B, the unbonded portions of the construction mesh sheet 1 and the unbonded portions of the repair sheet were gripped and the T-peel strength (N / 30 mm width) was measured. The T-peel strength was measured using an Autograph AG-1 manufactured by Shimadzu Corporation, with a gripping distance of 30 mm and a pulling speed of 100 mm / min. Of the obtained T-peel strength values, the values ​​for the three largest maximum values ​​were read and the average value was taken as the T-peel strength (N / 30 mm width).

[0032] Example 2 A T-shaped peel strength (N / 30 mm width) was obtained in the same manner as in Example 1, except that Mesh Sheet for Construction Work 2 was used instead of Mesh Sheet for Construction Work 1.

[0033] Example 3 A T-shaped peel strength (N / 30 mm width) was obtained in the same manner as in Example 1, except that mesh sheet 3 for construction work was used instead of mesh sheet 1 for construction work.

[0034] Comparative Example 1 A T-shaped peel strength (N / 30 mm width) was obtained in the same manner as in Example 1, except that mesh sheet 4 for construction work was used instead of mesh sheet 1 for construction work.

[0035] The T-shaped peel strengths (N / 30 mm width) obtained in Examples 1 to 3 and Comparative Example 1 are as shown in Table 1. [Table 1] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ T-shaped peel strength of specimen A T-shaped peel strength of specimen B ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 1 48.2 40.5 Example 2 42.6 34.7 Example 3 42.1 33.0 Comparative Example 1 31.3 23.8 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[0036] As can be seen from the results in Table 1, the T-peel strength of Examples 1 to 3, which used multifilament yarns constituting the mesh sheet for construction work that contained core-sheath composite filaments in which the core component was a polyethylene terephthalate polymer and the sheath component was a low-melting point copolymer polyester, was improved compared to Comparative Example 1, which did not contain this core-sheath composite filament. Therefore, it can be seen that the heat generated by dielectric heating of the vinyl chloride resin in the repair sheet caused only the sheath component to soften or melt, resulting in strong adhesion between the repair sheet and the mesh sheet for construction work.

[0037] Example 4 Test pieces A and B were obtained in the same manner as in Example 1. A 30 mm × 30 mm piece was also taken from the repair sheet used in Example 1 and used as the repair piece. The repair piece was placed on the right end of test piece A, and the left end of another test piece A was placed on top of this repair piece. This was then welded with a high-frequency welder under the same conditions as in Example 1 to produce 15 test pieces A. The left end (left end of test piece A) and right end (right end of the other test piece A) of test piece A were gripped, and the shear peel strength (N / 30 mm width) was measured. The shear peel strength was measured using an Autograph AG-1 manufactured by Shimadzu Corporation, with a gripping distance of 30 mm and a tensile speed of 200 mm / min. The values ​​of the three largest maximum values ​​were read from the obtained shear peel strengths, and the average value was used as the shear peel strength (N / 30 mm width). Furthermore, 15 test specimens B were prepared in the same manner as test specimen A, and the shear peel strength (N / 30 mm width) was measured.

[0038] Example 5 The shear peel strength (N / 30 mm width) was obtained in the same manner as in Example 4, except that the mesh sheet for construction work 2 was used instead of the mesh sheet for construction work 1.

[0039] Example 6 The shear peel strength (N / 30 mm width) was obtained in the same manner as in Example 4, except that the mesh sheet for construction work 3 was used instead of the mesh sheet for construction work 1.

[0040] Comparative Example 2 The shear peel strength (N / 30 mm width) was obtained in the same manner as in Example 4, except that the mesh sheet for construction work 4 was used instead of the mesh sheet for construction work 1.

[0041] The shear peel strengths (N / 30 mm width) obtained in Examples 4 to 6 and Comparative Example 2 are as shown in Table 2. [Table 2] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Shear peel strength of specimen A Shear peel strength of specimen B ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 4 982 1017 Example 5 498 567 Example 6 256 309 Comparative Example 2 184 267 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[0042] As can be seen from the results in Table 2, the shear peel strength of Examples 4 to 6, which used multifilament yarns constituting the mesh sheet for construction work that contained core-sheath composite filaments in which the core component was a polyethylene terephthalate polymer and the sheath component was a low-melting point copolymer polyester, was improved compared to Comparative Example 2, which did not contain this core-sheath composite filament. Therefore, it can be seen that the heat generated by dielectric heating and melting of the vinyl chloride resin in the repair sheet caused only the sheath component to soften or melt, resulting in strong adhesion between the repair sheet and the mesh sheet for construction work. [Brief explanation of the drawings]

[0043] [Figure 1] This is a diagram showing a three-strand brocade fabric. [Explanation of symbols]

[0044] 1. Weaving unit 2a, 2b, 2c weft 3a, 3b warp threads 4. Gap

Claims

1. A method for repairing a damaged portion of a mesh sheet for construction work, which is made of a woven fabric using multifilament yarns containing, as at least weft yarns, core-sheath composite filaments in which a core component is a polyethylene terephthalate polymer and a sheath component is a copolymer polyester having a melting point lower than that of the polyethylene terephthalate polymer, A repair sheet is prepared, which is made by laminating and integrating a vinyl chloride resin layer on at least the surface of a woven fabric having yarns made of polyethylene terephthalate polymer as warp and weft threads, A method for repairing a mesh sheet for construction work, characterized in that the damaged area is covered with the repair sheet and then subjected to a high-frequency welder to generate heat and melt the vinyl chloride resin layer through dielectric heating, and the heat generated by the vinyl chloride resin layer softens or melts the copolymer polyester, thereby bonding the mesh sheet for construction work and the repair sheet together.

2. 2. A method for repairing a mesh sheet for construction work according to claim 1, which comprises covering the repair sheet with a piece of the sheet for construction work according to claim 1, and adhering the repair sheet, the repair sheet and the piece together.

3. 2. The method for repairing a mesh sheet for construction work according to claim 1, wherein the fabric constituting the repair sheet is a plain weave fabric.

4. 4. The method for repairing mesh sheets for construction work according to claim 3, wherein the repair sheet comprises a plain weave fabric with vinyl chloride resin layers laminated integrally on both sides thereof.

5. 2. A method for repairing a mesh sheet for construction work according to claim 1, wherein the fabric constituting the mesh sheet for construction work is a pongee weave.

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