JP7548352B2 - Method for manufacturing fiber sheet laminate - Google Patents

Description

The present invention relates to a method for manufacturing a fiber sheet laminate, a fiber sheet laminate, and a concrete spalling prevention material using the fiber sheet laminate.

Conventionally, a method is known in which reinforcing materials are attached to the surface of a concrete structure in order to prevent spalling, repair, or reduce cracks in the concrete structure. For example, a spalling prevention material is known, which is made of a mesh made of glass fiber bundles or synthetic fiber bundles embedded inside a matrix of cement mortar, resin, or the like.

The following Patent Document 1 discloses a concrete spalling prevention material in which a mesh laminate is embedded inside a matrix resin. The mesh laminate includes a mesh composed of fiber bundles formed by bundling a plurality of filaments, a coating resin covering the mesh, and a nonwoven fabric bonded to the mesh by the coating resin. The coating resin is formed by applying the coating resin by a spraying method or a dipping method after weaving the mesh. Alternatively, the coating resin is applied and then further dried.

JP 2018-89822 A

Meanwhile, reinforcing materials such as concrete spalling prevention materials are sometimes cut to size according to the area of use at the construction site. They are also sometimes attached to areas where construction is difficult, such as vertical surfaces or ceiling surfaces. In such cases, if the mesh that constitutes the reinforcing material does not seal the fiber bundles well, misalignment may occur. As a result, when the mesh is cut to the size of the area of use or when handling it when attaching it to the construction surface, filaments may fall off, resulting in insufficient workability. Also, openings of a specified size may collapse, preventing the mesh from performing satisfactorily.

In addition, when the gaps between the fiber bundles are sealed by applying a coating resin as in Patent Document 1, the gaps between the filaments that make up the fiber bundle may be blocked by the coating resin, which may make it difficult for the matrix material to penetrate between the filaments. If it is difficult for the matrix material to penetrate between the filaments, the adhesion between the mesh and the matrix cannot be increased, and the reinforcing effect of the matrix by the mesh may not be fully achieved.

The object of the present invention is to provide a method for producing a fiber sheet laminate, a fiber sheet laminate, and a concrete spalling prevention material using the fiber sheet laminate, which can be easily produced, has excellent workability on site, and allows for easy impregnation of the matrix material between the filaments that make up the fiber bundle.

The method for producing a fiber sheet laminate according to the present invention is characterized by comprising the steps of: preparing a first sheet having a plurality of openings by weaving a fiber bundle made of a plurality of monofilaments with a heat-sealing yarn arranged along the fiber bundle; and laminating the first sheet on a second sheet made of a nonwoven fabric, paper, or film, and bonding the first sheet and the second sheet together by hot pressing at a temperature at which the fiber bundle does not soften.

In the present invention, it is preferable that the melting point of the heat-sealing yarn is 70°C or higher and 160°C or lower.

In the present invention, it is preferable that the heat-sealing yarn is made of one material selected from the group consisting of polyester, polyamide, polyacrylonitrile, polyvinyl alcohol, and polyolefin.

In the present invention, it is preferable that the yarn count of the heat-sealing yarn is 10 dtex or more and 500 dtex or less.

In the present invention, it is preferable that the fiber bundles in the first sheet are made of at least one type of fiber selected from the group consisting of carbon fiber, aramid fiber, glass fiber, vinylon fiber, polyester fiber, and polyolefin fiber. More preferably, the fiber bundles in the first sheet are made of the glass fiber.

In the present invention, it is preferable that the area of the opening in the first sheet is 1 ^mm2 or more and ⁴⁰⁰ mm2 or less.

In the present invention, it is preferable that the volume of the nonwoven fabric or the paper is 20 cm ³ /m ² or more and 1000 cm ³ /m ² or less.

The fiber sheet laminate of the present invention is characterized in that it comprises a first sheet, which is made of a fiber bundle of a plurality of monofilaments and has a fiber sheet having a plurality of openings and a heat-sealing thread, and a second sheet made of a nonwoven fabric, paper, or film, and the heat-sealing thread is disposed between the fiber sheet and the second sheet, and the first sheet and the second sheet are bonded together by the heat-sealing thread.

The concrete spalling prevention material of the present invention is characterized by comprising a matrix and a fiber sheet laminate constructed according to the present invention.

The present invention provides a method for producing a fiber sheet laminate that can be easily produced, has excellent on-site workability, and allows the filaments that make up the fiber bundle to be easily impregnated with a matrix material, a fiber sheet laminate, and a concrete spalling prevention material using the fiber sheet laminate.

FIG. 1 is a schematic plan view showing a first sheet used in a method for producing a fiber sheet laminate according to one embodiment of the present invention. FIG. 2 is a schematic plan view showing a modified example of the first sheet used in the method for producing a fiber sheet laminate according to one embodiment of the present invention. FIG. 3 is a schematic cross-sectional view for explaining a bonding step in the manufacturing method of a fiber sheet laminate according to one embodiment of the present invention. FIG. 4 is a schematic cross-sectional view for explaining details of the hot press in the manufacturing method of a fiber sheet laminate according to one embodiment of the present invention. FIG. 5 is a schematic cross-sectional view for explaining the effect as an example of the method for producing a fiber sheet laminate according to one embodiment of the present invention. FIG. 6 is a schematic cross-sectional view illustrating a bonding step in a method for producing a fiber sheet laminate according to another embodiment of the present invention. FIG. 7 is a schematic plan view showing a fiber sheet laminate according to one embodiment of the present invention. FIG. 8 is a schematic cross-sectional view of a portion taken along line AA in FIG. FIG. 9 is a schematic cross-sectional view showing a concrete spalling prevention material according to one embodiment of the present invention.

The following describes preferred embodiments. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. In addition, in the drawings, components having substantially the same functions may be referred to by the same reference numerals.

[Method of manufacturing fiber sheet laminate]
In the method for producing a fiber sheet laminate of the present invention, a first sheet having a plurality of openings is produced by weaving a fiber bundle made of a plurality of monofilaments with a heat-sealing yarn arranged along the fiber bundle (first sheet production step). Next, the first sheet produced is laminated on a second sheet made of a nonwoven fabric, paper, or film, and the first sheet and the second sheet are bonded together by hot pressing at a temperature at which the fiber bundle does not soften (bonding step). This allows a fiber sheet laminate to be obtained.

Below, we will explain each step in detail, dividing it into the first sheet production step and the lamination step.

(First Sheet Manufacturing Process)
Fig. 1 is a schematic plan view showing a first sheet used in a method for producing a fiber sheet laminate according to one embodiment of the present invention. Fig. 2 is a schematic plan view showing a modified example of the first sheet used in a method for producing a fiber sheet laminate according to one embodiment of the present invention.

In the manufacturing process of the first sheet 1, first, fiber bundles constituting the warp threads 2 and weft threads 3 are prepared. In this embodiment, the fiber bundles constituting the warp threads 2 and weft threads 3 are both glass fiber bundles. The glass fiber bundles can be obtained by bundling several tens to several hundreds of glass fiber monofilaments.

Glass fiber bundles are obtained by the following method. First, glass raw materials fed into a glass melting furnace are melted to produce molten glass, and the molten glass is made homogeneous. Then, the molten glass is drawn out from a heat-resistant nozzle attached to a bushing. The drawn molten glass is then cooled to produce glass fiber monofilaments (glass fibers).

Next, a sizing agent is applied to the surface of the glass fibers. With the sizing agent evenly applied, hundreds to thousands of the glass fibers are aligned and bundled together, then dried to obtain glass fiber bundles.

The glass fiber monofilaments constituting the glass fiber bundle preferably contain 12 mass% _ZrO2 and 10 mass% or more _R2O (R is at least one selected from Li, Na, and K) as the glass composition. In this case, the alkali resistance can be further improved and the rigidity can be further improved. Note that, "10 mass% or more of _R2O " means that the total content of _Li2O , _Na2O , and _K2O in the glass fiber monofilament is 10 mass% or more.

Such a glass fiber monofilament may, for example, contain, in mass %, 54-65% SiO ₂ , 12-25% ZrO ₂ , 0-5% Li ₂ O , 10-17% Na ₂ O , 0-8% K ₂ O , 0-10% R'O (wherein R' represents Mg, Ca, Sr, Ba, and Zn), 0-10% TiO ₂ , and 0-2% Al ₂ O ₃ , and preferably, in mass %, 57-64% SiO ₂ , 14-24% ZrO ₂ , 0-3% Li ₂ O , 10-17% Na ₂ O , 0-5% K ₂ O , 0.2-8% R'O (wherein R' represents Mg, Ca, Sr, Ba, and Zn), 0.2-8% TiO ₂ , and 0-2% Al 2 O 3 . It is possible to use one containing 0.5 to 9% of Al ₂ O ₃ and 0 to 1% of Al 2 O 3 .

The average diameter of the glass fiber monofilament is preferably 13 μm or more, more preferably 15 μm or more, and preferably 30 μm or less, more preferably 25 μm or less. When the average diameter of the glass fiber monofilament is equal to or greater than the above lower limit, the rigidity can be further increased. When the average diameter of the glass fiber monofilament is equal to or less than the above upper limit, the surface area can be further increased, and the adhesion to the matrix resin or cement can be further increased.

An example of a bundling agent used when bundling glass fiber monofilaments is polyester resin. The polyester resin may be a saturated polyester resin or an unsaturated polyester resin. It may also be a vinyl acetate resin, a urethane resin, an epoxy resin, or an acrylic resin. These may be used alone or in combination.

In addition to the above components, the binder preferably further contains a silane coupling agent. Examples of the silane coupling agent that can be used include aminosilane, epoxysilane, vinylsilane, acrylicsilane, chlorosilane, mercaptosilane, and ureidosilane. The addition of a silane coupling agent can further increase adhesion to the resin or cement that serves as the matrix.

In addition to the silane coupling agent, the sizing agent may contain other components such as a lubricant, a nonionic surfactant, a water-soluble polymer, and an antistatic agent, and the mixing ratio of each component may be determined as necessary. Examples of water-soluble polymers that can be used include polyvinyl alcohol, polyoxyethylene polyoxypropylene glycol, and polyvinylpyrrolidone.

It is preferable to adjust the amount of binder applied so that the ignition loss of the glass fiber bundle is 0.5 to 2.0% by mass. Ignition loss can be measured in accordance with JIS R3420 (2013).

However, the fiber bundles constituting the warp threads 2 and weft threads 3 are not limited to glass fiber bundles, and may be synthetic fiber bundles. Furthermore, the warp threads 2 and weft threads 3 may be made of the same fiber bundles as in this embodiment, or may be made of different fiber bundles. Furthermore, they may be made of a combination of multiple fibers. For example, the warp threads 2 may be glass fiber bundles and the weft threads 3 may be synthetic fiber bundles. The warp threads 2 may be synthetic fiber bundles and the weft threads 3 may be glass fiber bundles. However, from the viewpoint of further increasing the rigidity, it is preferable that glass fiber bundles are included.

Examples of fibers constituting the synthetic fiber bundle include carbon fibers, aramid fibers, vinylon fibers, polyester fibers, polyolefin fibers, etc. These fibers may be used alone or in combination. Of these, carbon fibers, aramid fibers, vinylon fibers, and polyolefin fibers are preferred. From the viewpoint of further improving heat resistance, the polyolefin fibers are preferably polypropylene fibers.

The count of the fiber bundles constituting the warp threads 2 and weft threads 3 is not particularly limited, but is preferably 100 tex or more and 3000 tex or less. When the count of the fiber bundles is within the above range, the rigidity of the fiber sheet 1 can be further increased.

The softening temperature of the fiber bundle is preferably 120°C or higher. In this case, it is possible to make it even more difficult for the bundle to break during hot pressing.

Next, the obtained fiber bundles are used as warp threads 2 and weft threads 3 to be woven by plain weaving. At this time, as shown in FIG. 1, the heat-sealing yarns 4 are arranged along the warp threads 2, and are woven in the same manner as the warp threads 2 to be woven. In this way, a first sheet 1 having a plurality of openings 5 can be obtained. The weaving method is not particularly limited, and may be leno weaving or twill weaving. However, from the viewpoint of making it easier to impregnate the material that will become the matrix, which will be described later, between the filaments that make up the fiber bundles, plain weaving is preferable.

The heat-sealing yarn 4 is a yarn that is fused by heating. In this embodiment, the heat-sealing yarn 4 is arranged so as to be aligned with all of the multiple warp threads 2. However, the heat-sealing yarn 4 may be arranged so as to be aligned with only some of the multiple warp threads 2.

The melting point of the heat-sealing yarn 4 is preferably 70°C or higher and 160°C or lower. If the melting point of the heat-sealing yarn 4 is equal to or higher than the lower limit, a wider variety of materials can be used. Also, if the melting point of the heat-sealing yarn 4 is equal to or lower than the upper limit, the fiber sheet 7 and the second sheet 10 can be made even more resistant to tearing.

The heat-sealing yarn 4 can be made of, for example, polyester, polyamide, polyacrylonitrile, polyvinyl alcohol, polyolefin, etc. Among these, it is preferable to make it of polyester, polyamide, or polyolefin, since it is easier to achieve a low melting point. These resins may be used alone or in combination.

The count of the heat-sealed yarn 4 is not particularly limited, but is preferably 10 dtex or more, more preferably 50 dtex or more, and preferably 500 dtex or less, and more preferably 350 dtex or less. When the thickness of the heat-sealed yarn 4 is equal to or greater than the above lower limit, the adhesion to the fiber sheet 7 and the second sheet 10 can be further improved. When the thickness of the heat-sealed yarn 4 is equal to or less than the above upper limit, the heat-sealed yarn 4 is less likely to penetrate between the multiple filaments that make up the fiber bundle, making it easier to impregnate the matrix material between the filaments.

The volume of the thermal fusion yarn 4 is preferably 0.1 ^cm3 / ^cm2 or more and 35.0 ^cm3 / ^cm2 or less with respect to the area of the main surface 10a of the second sheet 10 described later. In this case, the matrix material can be more easily impregnated between the filaments, and the bonding strength can be further increased. The volume of the thermal fusion yarn 4 is more preferably 1.0 ^cm3 / ^cm2 or more, even more preferably 3.0 ^cm3 / ^cm2 or more, and more preferably 30.0 ^cm3 / ^cm2 or less, and even more preferably 15.0 ^cm3 / ^cm2 or less.

2, the heat-sealed yarn 4A may be arranged so as to be aligned with the weft yarn 3. In the first sheet 1A, the heat-sealed yarn 4A is arranged on every other one of the multiple weft yarns 3. In the weft yarns 3, the heat-sealed yarn 4A may be arranged so as to be aligned with all the weft yarns 3, or may be arranged so as to be aligned with some of the weft yarns 3. The heat-sealed yarn 4A may be arranged so as to be aligned only with the weft yarn 3. The heat-sealed yarns 4, 4A may be arranged so as to be aligned with at least one fiber bundle of the multiple warp yarns 2 and the multiple weft yarns 3. However, it is preferable to arrange the heat-sealed yarns 4 so as to be aligned with all the fiber bundles (all the warp yarns 2) in one direction, as in the embodiment shown in FIG. 1. In this case, the first sheet 1 and the second sheet 10 can be bonded together more reliably during the bonding process, and the matrix material described below can be more easily impregnated between the filaments that make up the fiber bundle.

In this embodiment, the heat-sealed yarns 4, 4A are arranged so as to extend parallel to the warp yarns 2 and weft yarns 3 (fiber bundles). However, the heat-sealed yarns 4, 4A may be entangled with the fiber bundles. From the viewpoint of making it easier to impregnate the filaments constituting the fiber bundles with the matrix material described below, it is preferable to arrange the heat-sealed yarns 4, 4A so as to extend parallel to the fiber bundles as in this embodiment. In this case, it is also preferable to arrange the heat-sealed yarns 4, 4A so as to be in contact with the fiber bundles. However, the heat-sealed yarns 4, 4A may be in partial contact with the fiber bundles, or may be in complete contact.

In this embodiment, the area of the openings 5 in the first sheet 1 is preferably ¹ mm2 or more and ⁴⁰⁰ mm2 or less. When the area of the openings 5 is equal to or more than the above-mentioned lower limit, the material to be the matrix described below can pass through more easily, and the adhesion between the material to be the matrix and the fiber sheet laminate can be further improved. When the area of the openings 5 is equal to or less than the above-mentioned upper limit, the area ratio of the fiber bundles constituting the first sheet 1 can be further increased, and therefore the first sheet 1 and the second sheet 10 can be more reliably bonded together in the bonding process.

The thickness of the first sheet 1 is not particularly limited, but can be, for example, 0.2 mm or more and 1 mm or less.

(Laminating process)
Fig. 3 is a schematic cross-sectional view for explaining a lamination step in the method for producing a fiber sheet laminate according to one embodiment of the present invention. Fig. 4 is a schematic cross-sectional view for explaining a heat pressing method in the method for producing a fiber sheet laminate according to one embodiment of the present invention. Fig. 5 is a schematic cross-sectional view for explaining the effect of the method for producing a fiber sheet laminate according to one embodiment of the present invention.

In the lamination process, first, the second sheet 10 is prepared. In this embodiment, the second sheet 10 is a nonwoven fabric. The second sheet 10 may also be a paper or a film. It is preferable that the second sheet 10 is a continuous sheet.

The fibers constituting the nonwoven fabric or paper are not particularly limited, but examples include glass fibers, polyester fibers, polyethylene fibers, polypropylene fibers, rayon fibers, nylon fibers, acrylic fibers, vinylon fibers, polylactic acid fibers, etc. These fibers may be used alone or in combination.

Nonwoven fabric is a sheet-like material made by intertwining these fibers without weaving them. Paper is a fiber paper made from these fibers.

The volume of the nonwoven fabric or paper is not particularly limited, but is preferably 20 ^cm3 / ^m2 or more and 1000 ^cm3 / ^m2 or less. When the volume of the nonwoven fabric or paper is equal to or more than the above lower limit, the strength as a continuous sheet can be further increased, and it can be made even more difficult to break during hot pressing. On the other hand, when the volume of the nonwoven fabric or paper is equal to or less than the above upper limit, it can be made even easier for the matrix material to permeate, and the adhesion to the matrix can be further increased.

The thickness of the nonwoven fabric or paper is not particularly limited, but is preferably 0.02 mm or more and 1 mm or less. If the thickness of the nonwoven fabric or paper is within the above range, the strength as a continuous sheet can be further increased, and it will be even less likely to break during hot pressing.

The film is not particularly limited, but examples include polyolefin films such as polypropylene film and polyethylene film, polyethylene terephthalate film, and fluorine-based films. These may be used alone or in combination.

The basis weight of the film is not particularly limited, but is preferably 5 g/ ^m2 or more and 200 g/ ^m2 or less. When the basis weight of the film is within the above range, the strength as a continuous sheet can be further increased, and it becomes more difficult to break during hot pressing. The basis weight of the film is more preferably 20 g/ ^m2 or more and 100 g/ ^m2 or less.

The thickness of the film is not particularly limited, but is preferably 10 μm or more and 100 μm or less. If the thickness of the film is within the above range, the strength as a continuous sheet can be further increased, and it will be even less likely to break during hot pressing.

The film is preferably a transparent film. In this specification, "transparent" means that the light transmittance in the visible wavelength range of 450 nm to 700 nm is 70% or more.

The softening temperature of the nonwoven fabric, paper, and film is preferably 120°C or higher. In this case, they are even less likely to break during hot pressing.

Next, as shown in FIG. 3, the first sheet 1 described above is laminated on the main surface 10a of the second sheet 10. Then, in the state where the first sheet 1 is laminated on the second sheet 10, it is heat pressed. In this way, the first sheet 1 and the second sheet 10 are bonded together to obtain a fiber sheet laminate. Note that details of the first sheet 1, such as the heat-sealing yarn 4, are omitted from FIG. 3.

The hot pressing can be performed, for example, by a hot roll press or a hot mold press. The hot pressing is performed at a temperature at which the fiber bundles (warp threads 2 and weft threads 3) constituting the first sheet 1 do not soften. It is also desirable to perform the hot pressing at a temperature at which the second sheet 10 does not soften. Note that "a temperature at which the second sheet 10 does not soften" refers to a temperature lower than the softening point in the case of a material that has a softening point, and refers to a temperature equal to or lower than the softening point in the case of a material that does not have a softening point.

The temperature of the heat press depends on the type of material constituting the fiber bundle, but is preferably 80° C. or more, more preferably 100° C. or more, and is preferably 250° C. or less, more preferably 160° C. or less. The pressure of the heat press is preferably 5 N/cm ² or more, more preferably 7 N/cm ² or more, and is preferably 40 N/cm ² or less, more preferably 15 N/cm ² or less.

When the fiber bundles constituting the first sheet 1 are polypropylene fibers, which are a type of polyolefin fiber, the fiber bundles may shrink due to the heat press, causing the warp threads 2 or weft threads 3 to meander. Since polypropylene fibers may shrink due to this heat press and cause meandering in the mesh, especially the weft threads, preheating may be performed before weaving. Preheating makes it even more difficult for meandering to occur even when hot press processing is performed. There are no particular limitations on the preheating conditions, but specifically, preheating that results in a reduction in breaking elongation in a tensile test of 1 to 15% is preferable.

In this embodiment, the first sheet 1 is laminated on the second sheet 10, and then heated and pressed to melt the heat-sealing yarns 4. In this state, the first sheet 1 and the second sheet 10 can be bonded together while sealing the warp yarns 2 and weft yarns 3 that make up the first sheet 1 by pressing in the X direction (thickness direction of the laminate) shown in FIG. 4.

In this way, in the manufacturing method of this embodiment, the first sheet 1 and the second sheet 10 can be bonded together while sealing the warp yarns 2 and weft yarns 3 that constitute the first sheet 1 by interposing the heat-sealing yarns 4. Therefore, the fiber sheet laminate can be easily manufactured, has excellent workability on site, and can easily impregnate the matrix material between the filaments that constitute the fiber bundle. This will be described in detail below in comparison with the conventional manufacturing method. Conventionally, when manufacturing a fiber sheet laminate by bonding a mesh fabric to a sheet such as a nonwoven fabric, first, the mesh fabric is woven and then a coating resin is applied as a secondary binder. Furthermore, after a drying process is performed as necessary, the mesh fabric is bonded to a sheet such as a nonwoven fabric to obtain a fiber sheet laminate.

In contrast, in the manufacturing method of this embodiment, the thermally fused yarn 4 is woven together with fiber bundles such as warp yarn 2 during weaving, and then a sheet such as a nonwoven fabric is layered on top of the sheet and heat-pressed to obtain a fiber sheet laminate. Therefore, there is no need for complicated processes such as coating resin application and drying processes as in conventional manufacturing methods. A fiber sheet laminate can be easily obtained by layering a first sheet 1, into which thermally fused yarn 4 is woven together with fiber bundles, on a second sheet 10 and then heat-pressing the first sheet 1.

As shown in FIG. 4, the warp threads 2 and weft threads 3 constituting the first sheet 1 are sealed by a heat press with a heat-sealing thread 4, and the first sheet 1 and the second sheet 10 are bonded together. Therefore, the warp threads 2 and weft threads 3 can be reliably sealed by also interposing the second sheet 10. Therefore, since the obtained fiber sheet laminate is less likely to have misalignment, it is possible to prevent filaments from falling off during handling when cutting the fiber sheet laminate or attaching it to the application surface at the site. Therefore, the obtained fiber sheet laminate is also excellent in terms of workability at the site. In addition, since the openings 5 of a specified size are less likely to collapse, it is possible to demonstrate sufficient performance as a fiber sheet laminate.

In addition, in the manufacturing method of this embodiment, the heat-sealing yarn 4 is fused to a part of the fiber bundles constituting the first sheet 1 to seal the gaps between the fiber bundles and to bond the first sheet 10 to the second sheet 10. Therefore, unlike the conventional manufacturing method in which a coating resin is applied, the gaps between the filaments constituting the fiber bundles are unlikely to be blocked. Therefore, for example, as shown in FIG. 5, when the fiber sheet laminate is embedded in the resin 6 that becomes the matrix, the resin 6 that becomes the matrix can be reliably impregnated between the filaments that make up the fiber bundles. Therefore, the adhesiveness between the resin 6 that becomes the matrix and the fiber sheet laminate can be improved, and the reinforcing effect of the matrix by the fiber sheet laminate can be improved. The fiber sheet laminate embedded in the resin 6 that becomes the matrix can be attached to, for example, a concrete structure 32 shown in FIG. 5.

In addition, since no secondary binder is used, the spaces between the filaments that make up the fiber bundle are not blocked, and the spaces between the filaments can be easily impregnated with resin 6, which acts as a matrix. This makes it possible to achieve greater transparency when the fiber bundle is made of glass fibers, as in this embodiment. Therefore, when the obtained fiber sheet laminate is attached to the surface of a concrete structure, for example, it makes it easier to visually observe the surface condition of the concrete structure.

Figure 6 is a schematic cross-sectional view illustrating the lamination step in a method for producing a fiber sheet laminate according to another embodiment of the present invention.

In another embodiment of the manufacturing method shown in FIG. 6, a second sheet 10 is laminated on each of the main surfaces 1a, 1b of a first sheet 1 and then hot-pressed. This bonds the first sheet 1 and the second sheet 10 together to produce a fiber sheet laminate in which the first sheet 1 is sandwiched between the two second sheets 10. Other points are the same as in the embodiment shown in FIG. 3. Note that the details of the first sheet 1, such as the heat-sealing yarn 4, are also omitted from FIG. 6.

In this way, the second sheet 10 may be bonded to each of the main surfaces 1a, 1b on both sides of the first sheet 1. Even in this case, the first sheet 1 and the second sheet 10 can be bonded together while sealing the warp threads 2 and weft threads 3 that make up the first sheet 1 by interposing the heat-sealing yarn 4. This makes it possible to easily manufacture the fiber sheet laminate, has excellent on-site workability, and allows the matrix material to be easily impregnated between the filaments that make up the fiber bundle.

In addition, when a second sheet 10 is attached to each of the main surfaces 1a and 1b on both sides of the first sheet 1, the second sheet 10 can absorb even more of the matrix resin, further suppressing resin dripping.

Below, we will provide a detailed description of an example of a fiber sheet laminate manufactured using a manufacturing method according to one embodiment of the present invention.

[Fiber sheet laminate]
Fig. 7 is a schematic plan view showing a fiber sheet laminate according to one embodiment of the present invention. Fig. 8 is a schematic cross-sectional view of a portion taken along line A-A in Fig. 7. Note that the thermal adhesive yarn 4 is omitted from Fig. 7.

As shown in Figures 7 and 8, the fiber sheet laminate 20 includes a first sheet 1 and a second sheet 10. The first sheet 1 includes a fiber sheet 7 and a heat-sealing yarn 4. The fiber sheet 7 is a mesh fabric woven from the warp yarns 2 and weft yarns 3 described above. The fiber sheet 7 is the portion of the first sheet 1 excluding the heat-sealing yarns 4.

The heat-sealing yarn 4 is woven together with the warp yarn 2 and the weft yarn 3. The heat-sealing yarn 4 is also arranged so as to be interposed between the fiber sheet 7 and the second sheet 10. In particular, in this embodiment, the heat-sealing yarn 4 is arranged so as to be interposed between the main surface 7a of the fiber sheet 7 and the main surface 10a of the second sheet 10. As a result, the first sheet 1 and the second sheet 10 are bonded together by the heat-sealing yarn 4.

The fiber sheet laminate 20 can be easily manufactured by layering a first sheet 1, in which thermally fused yarns 4 are woven together with fiber bundles such as warp yarns 2, on a second sheet 10, and then hot pressing the resulting sheet.

In addition, the second sheet 10 is attached by hot pressing with the heat-sealing threads 4 in between, and the warp threads 2 and weft threads 3 that make up the first sheet 1 are sealed, ensuring that they are sealed. As a result, there is little risk of misalignment, making it easy to install on site.

In addition, because the fibers are bonded together using heat-sealed yarn 4, the filaments that make up the fiber bundles, such as warp yarn 2, can be easily impregnated with matrix material, which increases the adhesion between the matrix material and fiber sheet laminate 20, and the fiber sheet laminate 20 can also provide a reinforcing effect for the matrix.

[Concrete spalling prevention material]
Fig. 9 is a schematic cross-sectional view showing a concrete spalling prevention material according to one embodiment of the present invention. As shown in Fig. 9, the concrete spalling prevention material 31 includes a fiber sheet laminate 20 and a matrix resin 33. The fiber sheet laminate 20 is the fiber sheet laminate 20 according to the embodiment described above. The mesh laminate 20 is embedded inside the matrix resin 33. The concrete spalling prevention material 31 is provided on a concrete structure 32.

In this way, in the concrete spalling prevention material 31, the fiber sheet laminate 20 is embedded inside the matrix resin 33. When the fiber sheet laminate 20 is embedded in the matrix resin 33 as described above, the matrix resin 33 can be reliably impregnated between the filaments that make up the fiber bundle. This improves the adhesion between the matrix resin 33 and the fiber sheet laminate 20, and enhances the reinforcing effect of the matrix resin by the fiber sheet laminate 20. In addition, since the matrix resin 33 can be easily impregnated between the filaments that make up the fiber bundle, when the fiber bundle is made of glass fiber as in this embodiment, it is possible to achieve greater transparency. Therefore, the fiber sheet laminate 20 makes it easy to visually observe the surface condition of the concrete structure 32.

In this embodiment, the first sheet 1 is disposed on the concrete structure 32 side. However, it is preferable that the first sheet 1 is disposed on the concrete structure 32 side as in this embodiment, but the second sheet 10 may be disposed on the concrete structure 32 side.

The matrix resin 33 is not particularly limited, and examples thereof include epoxy resin, acrylic resin, urethane resin, and silicone resin. These may be used alone or in combination.

The concrete spalling prevention material 31 can be formed, for example, by applying a primer and undercoat resin onto the concrete structure 32, and then laminating the fiber sheet laminate 20. Also, after laminating the fiber sheet laminate 20, a topcoat resin may be applied.

The present invention will be described in more detail below based on specific examples. The present invention is not limited to the following examples, and can be modified as appropriate within the scope of the gist of the invention.

Example 1
First, raw materials were prepared to obtain glass having a composition of 57.9 mass% SiO ₂ , 17.2 mass% ZrO ₂ , 0.5 mass% Li ₂ O, 14.8 mass% Na ₂ O, 1.3 mass% K ₂ O, 0.9 mass% CaO, and 7.4 mass% TiO ₂ , and the molten glass was drawn out as glass fiber monofilaments from a bushing having hundreds to thousands of nozzles.

Next, a sizing agent, which was a water dispersion of vinyl silane, saturated polyester resin, and a lubricant, was applied to the surface of the obtained glass fiber monofilament using an applicator so that the ignition loss was 0.7% by mass. The glass fibers were bundled, and the sizing agent was dried to produce a glass fiber bundle (count: 320 tex).

Next, a first sheet 1 shown in Fig. 1 was produced. Specifically, the glass fiber bundles obtained as described above were used as warp yarns 2 and weft yarns 3, and polyester yarns (melting point: 110°C, count: 110 dtex) serving as heat-fusible yarns 4 were arranged along the warp yarns 2, and woven at 9 warp and weft/25 mm, and woven by plain weaving at 230 g/ ^m2 to obtain a first sheet 1.

Next, the first sheet 1 was placed on top of a polyester nonwoven fabric (volume: 10 ^cm3 / ^m2 , thickness: 0.06 mm) as the second sheet 10, and the first sheet 1 was heated and pressed at a temperature of 120°C and a pressure of 10 N/ ^cm2 using a hot roll press to obtain a mesh sheet laminate of Example 1.

Example 2
A mesh sheet laminate of Example 2 was obtained in the same manner as in Example 1, except that glass paper (volume: 4 cm ³ /m ² , thickness: 0.18 mm) was used as the second sheet 10 instead of the polyester nonwoven fabric.

Example 3
The above glass fibers and polypropylene fiber bundles (count: 900 dtex) were woven in the warp and weft directions at 6 fibers/25 mm, and woven by plain weaving at 197 g/ ^m2 . A mesh sheet laminate of Example 3 was obtained in the same manner as in Example 1.

However, the polypropylene fibers shrink during this heat press, causing the mesh to meander, especially the weft threads, so the fabric was preheated at 120°C for 30 minutes before weaving.

Example 4
The above glass fiber and aramid fiber bundles (count: 1670 dtex) were woven in the warp and weft directions at 5 strands/25 mm, and woven by plain weaving at 195 g/ ^m2 . A mesh sheet laminate of Example 4 was obtained in the same manner as in Example 1.

The mesh sheet laminates obtained in Examples 1 to 4 were cut into pieces measuring 100 mm in length and 100 mm in width to create 10 samples. Next, the 10 samples were pulled in one direction to evaluate workability based on whether the first sheet and the second sheet 10 separated. As a result, in each Example, the number of samples in which the first sheet and the second sheet 10 separated was 0.

In addition, when the mesh sheet laminates obtained in Examples 1 to 4 were pulled 30 mm in the vertical direction, no misalignment of the first sheet occurred.

Reference Signs List 1, 1A... First sheet 1a, 1b... Main surface 2... Warp thread 3... Weft thread 4, 4A... Heat-sealed thread 5... Opening 6... Resin 7... Fiber sheet 10... Second sheet 20... Fiber sheet laminate 31... Concrete spalling prevention material 32... Concrete body 33... Matrix resin

Claims (8)

a step of weaving a fiber bundle made of a plurality of monofilaments in a state in which a heat-sealing yarn is arranged along the fiber bundle to produce a first sheet having a plurality of openings;
laminating the first sheet on a second sheet made of a nonwoven fabric, paper, or film, and heat-pressing the first sheet at a temperature at which the fiber bundle does not soften, thereby bonding the first sheet and the second sheet;
A method for producing a fiber sheet laminate, comprising:
The fiber bundle constituting the first sheet includes a polypropylene fiber bundle,
a step of preheating the polypropylene fiber bundles before the weaving in the step of producing the first sheet such that a reduction rate of breaking elongation in a tensile test of the polypropylene fiber bundles is 1 to 15% . The method for producing a fiber sheet laminate according to claim 1 , wherein the melting point of the heat-fusible yarn is 70°C or higher and 160°C or lower. 3. The method for producing a fiber sheet laminate according to claim 1 , wherein the heat-sealing yarn is made of one material selected from the group consisting of polyester, polyamide, polyacrylonitrile, polyvinyl alcohol, and polyolefin. The method for producing a fiber sheet laminate according to any one of claims 1 to 3 , wherein the thermal adhesive yarn has a count of 10 dtex or more and 500 dtex or less. 5. The method for producing a fiber sheet laminate according to claim 1, wherein the fiber bundles in the first sheet further contain at least one type of fiber selected from the group consisting of carbon fiber, aramid fiber, glass fiber, vinylon fiber, polyester fiber , and polyolefin fiber excluding polypropylene fiber . The method for producing a fiber sheet laminate according to any one of claims 1 to 4 , wherein the fiber bundles in the first sheet further contain the glass fibers. The method for producing a fiber sheet laminate according to any one of claims 1 to 6 , wherein the area of the opening of the first sheet is 1 ^mm2 or more and ⁴⁰⁰ mm2 or less. The method for producing a fiber sheet laminate according to any one of claims 1 to 7 , wherein the volume of the nonwoven fabric or the paper is 20 cm ³ /m ² or more and 1000 cm ³ /m ² or less.

Images