JPWO2010147231A1 - Reinforcing fiber sheet material - Google Patents

Abstract

The present invention can prevent deformation and shrinkage of the chain structure holding the reinforcing fiber bundle, prevent meandering of the reinforcing fiber bundle, and even when a plurality of layers are laminated to form an FRP. An object of the present invention is to provide a reinforcing fiber sheet material that is excellent in formability, has a high Vf, and has excellent mechanical properties. Specifically, each of the auxiliary insertion yarns 3 knitted into the chain structure W · W ... is swung to the outside for every predetermined course, and the single or plural reinforcing fiber bundles 1 are separated from each other. The chain structures W are parallel to each other, the chain structures W · W are connected to each other in a subtracted state, and both sides of the reinforcing fiber bundle 1 are sandwiched. A technical means was adopted in which the reinforcing fiber bundle 1 and the auxiliary yarn warp knitted fabric were integrated by inserting along the longitudinal direction of the sheet material and fusing at the intersection of the auxiliary insertion yarn 3.

Description

  The present invention is an improvement of a reinforcing fiber sheet material. More specifically, the reinforcing fiber bundle is prevented from meandering, and a plurality of sheets are laminated and formed into FRP (Fiber-Reinforced-Plastics, hereinafter referred to as “FRP”). The present invention also relates to a reinforcing fiber sheet material that does not decrease in strength and can increase the volume content of reinforcing fibers.

  As is well known, in a construction site, in order to reinforce an existing concrete structure (for example, a bridge pier) or prevent peeling on the surface, a resin is impregnated into a reinforcing fiber sheet such as carbon fiber and then the resin is cured. Reinforcing work for adhering the produced FRP has been performed, and the present applicant has developed such a reinforcing fiber sheet material (see Patent Document 1).

  In the sheet material of <Patent Document 1>, a thread made of a low-melting point thermoplastic resin (hereinafter simply referred to as a “polymer”) is spirally wound around the auxiliary insertion thread to cover the chain structure. The reinforcing fiber bundles were sandwiched between both sides by knitting together, separating the reinforcing fiber bundles for every fixed course, knitting them into chain structures parallel to the sides, and connecting the chain structures together. .

  However, the sheet material of <Patent Document 1> has a low-melting point thermoplastic resin yarn (hereinafter referred to as “low-melting point polymer yarn”) or simply “ Polymer yarn) is firmly heat-sealed over the entire width of the flat reinforcing fiber bundle surface, so if the chain structure is deformed or contracts in the longitudinal direction of the sheet, it is strengthened with this deformation and contraction. There is a problem that the fiber bundle is drawn into each longitudinal section and the meandering occurs in the sheet. When the meandering occurs in the reinforcing fiber bundle, the strength of the sheet is greatly reduced, and the desired strength of the FRP There was a problem that could not be obtained.

  As described above, deformation and shrinkage of the chain structure in the auxiliary yarn warp knitted fabric (hereinafter also simply referred to as “warp knitted fabric”) is knitted sheet material combined with thermal fusion between the insertion yarn and the reinforcing fiber bundle. This causes the meandering of the reinforcing fiber bundle that constitutes, and the cause is as follows.

  First, when knitting a sheet material, tension is applied to the chain knitted fabric yarn and the insertion yarn, whereas when winding up in a roll shape, these warp knitted fabrics are pulled by the tension, so the loop of the chain structure Will be stretched in the longitudinal direction of the sheet, and the chain knitted fabric yarn will inevitably be refracted at the location where the loops are connected.

  When the roll around which the sheet is wound is unwound, the chain knitted fabric yarn contracts to return to its original state due to elasticity, and the portion that is refracted at the extreme refracted portion of the portion where the loops are connected to extend in the longitudinal direction of the sheet is gently rounded. As a result, the loop becomes shorter and the reinforcing warp knitted fabric shrinks in the longitudinal direction of the sheet.

  Next, the insertion yarn knitted into the chain structure is coated with a polymer yarn, and this polymer yarn is fused to the chain structure and the insertion yarn by heat treatment, and the chain structure and the insertion yarn are bonded. However, at this time, if the heat treatment conditions of the chain knitted fabric yarn and the insertion yarn are not sweet enough, the warp knitted fabric will shrink in the longitudinal direction of the sheet without suppressing the shrinkage of the chain knitted fabric yarn and the insertion yarn. There is.

  In addition, as a meandering cause other than chain structure deformation and contraction, for example, when the sheet is unwound from the roll wound around the sheet material in the next process of lamination or prepreg process, the sheet outer surface in the roll A difference in length due to a path difference (circumferential diameter difference) on the inner surface cannot be absorbed, and the outer surface side of the sheet may change from a convex state to a concave state.

  That is, the length of the outer portion in the reinforcing fiber bundle is longer than that of the inner portion, but the insertion yarns are arranged in the width direction of the sheet. It is firmly fused over the entire width of the reinforcing fiber bundle surface and integrated with the warp knitted fabric. Therefore, a phenomenon in which the reinforcing fiber bundle meanders in the width direction or the thickness direction of the sheet surface without being able to absorb the elongated reinforcing fiber anywhere.

  In addition, the polymer yarn covered with the insertion yarn adheres the chain knitted fabric yarn and the insertion yarn to stop the movement of the insertion yarn in the chain structure, and the insertion yarn extends over the entire width of the flat reinforcing fiber bundle surface. Since the inserted yarn could not be stretched in the sheet width direction due to bonding, the shape stability was excellent, but conversely, the shapeability inherent to the knitted fabric structure was not sufficiently obtained.

  Furthermore, the sheet material of <Patent Document 1> uses a relatively thick yarn as a chain knitted fabric yarn or an insertion yarn, and a polymer yarn is wound around the insertion yarn in a spiral manner to cover it. There is a problem that the diameter of the yarn as the whole yarn becomes thick and the chain structure protrudes in the thickness direction in the sheet surface.

  Furthermore, in the sheet material of <Patent Document 1>, the insertion yarn intersects the reinforcing fiber bundle and sandwiches both sides of the reinforcing fiber bundle, and the polymer is inserted over at least one of the insertion yarns sandwiching both surfaces. Since the yarn is covered, the diameter of the inserted yarn as a whole is large when the covered portion is included.

  Then, when FRP is formed by laminating a plurality of such sheet materials, a thick insertion thread exists partially between the sheet layers, so that the portion becomes thicker and resin rich in the thickness direction (resin pool). The gap becomes larger.

  That is, when the sheet material is laminated, there is a gap in which no reinforcing fiber exists between the layers. Therefore, the gap is filled with resin, and the fiber content Vf (Fiber-volume-content, hereinafter referred to as “FRP-volume-content”). There is a problem that Vf ") becomes low.

  Further, in such a configuration, if pressure is applied in the thickness direction of the sheet during molding, the insertion yarn partially presses the reinforcing fiber bundle, so that the reinforcing fiber bundle may meander in the thickness direction. It was.

  For this reason, there has been a problem that FRP excellent in mechanical properties cannot be obtained. In addition, although the sheet | seat material which employ | adopted the knitting form is mentioned here as an example, it can be said also to the one-way fabric which used the auxiliary yarn for the weft.

  In addition, the sheet material of <Patent Document 1> is a sheet material having a high ratio of polymer components other than the reinforcing fibers because all the chain structures were inserted and knitted with an insertion yarn coated with a polymer yarn.

  Thus, when there are many components other than the reinforcing fiber, there is a problem that when FRP is formed, Vf becomes low and FRP excellent in mechanical properties cannot be obtained. Further, when the content of the polymer component is large, the heat resistance temperature is low, so that there is a problem that the heat resistance of the FRP as a whole is lowered.

  Further, in the sheet material of <Patent Document 1>, there are places where the insertion yarns are arranged even in the sheet width direction, and the heat shrinks due to the heat treatment, and also contracts in the sheet width direction. Then, when looking at the unit of one sheet, it is stable because the insertion thread pulls each chain structure to balance each other at the center in the width direction, but at the outermost edge of the sheet, Since there is no adjacent tissue, they can not be balanced by pulling each other, the force to shrink to the center part of the sheet increases, and the amount of contraction at the end edge of the sheet is compared to the center part growing.

  Therefore, since the structure of the outermost edge portion is denser in the sheet width direction than the center portion in the sheet width direction, a large difference occurs in the basis weight of the reinforcing fibers at the center portion and the outermost edge portion. In other words, the basis weight at the center in the sheet width direction becomes light and the end edge becomes heavy.

  In such a sheet material, there is a portion where the amount of reinforcing fibers is different in the width direction. Therefore, when the FRP is manufactured at the end edge where the amount of reinforcing fibers is large, the thickness is increased, but the thickness is decreased in the central portion. Thus, there was a problem that FRP with a uniform thickness could not be obtained, and the quality would vary greatly.

Japanese Patent No. 4167842

  The present invention has been made in view of the above-mentioned drawbacks of conventional reinforcing fiber sheet materials, and its purpose is to prevent deformation and shrinkage of the chain structure holding the reinforcing fiber bundle, Reinforced fiber sheet that prevents meandering of fiber bundles, and has excellent formability, FRP with high Vf, and excellent mechanical properties even when multiple sheets are laminated to form FRP To provide materials.

  Means employed by the present inventor for solving the above-described problems will be described with reference to the accompanying drawings.

That is, the present invention is configured by holding the reinforcing fiber bundles 1.1 of the required width in which the reinforcing fibers are arranged in parallel by the auxiliary yarn warp knitted fabric,
The auxiliary yarn warp knitted fabric includes a chain knitted fabric yarn 2 forming a plurality of rows of chain structures W · W arranged along a predetermined wale interval between the reinforcing fiber bundles 1 and 1, and the chain knitted fabric. While comprising the auxiliary insertion yarn 3 knitted into the chain structure W formed by the yarn 2,
Each of the auxiliary insertion yarns 3 knitted into these chain structures W · W is swung to the outside for every fixed course, and one or a plurality of reinforcing fiber bundles 1 are spaced apart and parallel to the side. The chain structure W is knitted, and the chain structures W and W are connected to each other in a subtracted state to sandwich both surfaces of the reinforcing fiber bundle 1,
A technique of inserting the reinforcing fiber bundle 1 and the auxiliary yarn warp knitted fabric by inserting the low melting polymer yarn 4 along the longitudinal direction of the sheet material and fusing at the intersection of the auxiliary insertion yarn 3. Reinforcing fiber sheet material was completed by adopting special means.

  In addition, in order to solve the above-described problems, the present invention inserts the low-melting polymer yarn 4 along the longitudinal direction of the reinforcing fiber bundle 1 in addition to the above means as necessary, and a part of the auxiliary insertion yarn 3 At least the surface is brought into contact, the polymer yarn 4 is melted by heat treatment, and the reinforcing fiber bundle 1 and the auxiliary insertion yarn 3 are fused in the form of dots, whereby the reinforcing fiber bundle 1 and the insertion yarn 3 are loosely contacted. In other words, a technical means of sandwiching the reinforcing fiber bundle 1 was adopted.

  Furthermore, in order to solve the above-described problems, the present invention includes a composite yarn obtained by coating the low knitted polymer yarn 4 on the chain knitted fabric yarn 2 and the auxiliary insertion yarn 3 in addition to the above means as necessary. The technical means of knitting integrally and fusing the low melting point polymer yarn 4 to the chain knitted fabric yarn 2 by heat treatment to fix the structure was adopted.

  Furthermore, in order to solve the above-mentioned problems, the present invention knitted the low melting point polymer yarn 4 into the chain structure W by inserting one needle in addition to the above means as necessary, and the chain knitting of this chain structure W. A technical means was adopted in which the ground yarn 2 and the auxiliary insertion yarn 3 were knitted together and the low-melting polymer yarn 4 was fused to the chain-knitted fabric yarn 2 by heat treatment to fix the structure.

  Furthermore, in order to solve the above-mentioned problems, the present invention knitted together with the auxiliary insertion yarn 3 by pulling together the low-melting point polymer yarn 4 and the chain knitted fabric yarn 2 together in addition to the above means as necessary. Then, a technical means was adopted in which the low melting point polymer yarn 4 was fused to the chain knitted fabric yarn 2 by heat treatment to fix the structure.

  Furthermore, in order to solve the above-mentioned problems, the present invention employs technical means for attaching the low-melting polymer yarn 4 along all the chain structures W in addition to the above-described means as necessary.

  Furthermore, in order to solve the above-mentioned problems, the present invention employs technical means for setting the fineness of the low-melting polymer yarn 4 to 10 to 120 dtex in addition to the above means as necessary.

  Furthermore, in order to solve the above-mentioned problems, the present invention sets the fineness of the chain knitted fabric yarn 2 and the auxiliary insertion yarn 3 to 10 to 90 dtex in addition to the above means as necessary, and this chain knitted fabric yarn 2 The technical means of preventing the contraction in the longitudinal direction of the chain structure W was adopted.

  Furthermore, in order to solve the above-mentioned problem, the present invention, in addition to the above means, in addition to the above-mentioned means, the dry heat shrinkage rate (JIS L 1013 (Method B)) of the chain knitted fabric yarn 2 and the auxiliary insertion yarn 3 is The technical means of 4.0% or less was adopted.

  Furthermore, in order to solve the above-mentioned problems, the present invention employs technical means in which the chain knitted fabric yarn 2 and the auxiliary insertion yarn 3 are made into multifilament yarns in addition to the above-described means as necessary.

  Furthermore, in order to solve the above-mentioned problems, the present invention comprises one or more kinds of reinforcing fibers of the reinforcing fiber bundle 1 among carbon fibers, glass fibers, and aramid fibers in addition to the above means as necessary. The technical means of doing so was adopted.

  Furthermore, in order to solve the above-described problems, the present invention provides a technique for making the chain-knitted fabric yarn 2 and the auxiliary insertion yarn 3 into a thermoplastic resin yarn that melts into an epoxy resin, in addition to the above-described means, if necessary. Adopted the means.

In the present invention, a reinforcing fiber bundle having a required width in which reinforcing fibers are arranged in parallel is held by a warp knitted fabric, and the warp knitted fabric is arranged between the reinforcing fiber bundles along a predetermined wale interval. While composed of a chain knitted fabric yarn that forms a chain structure of a plurality of rows and an insert yarn knitted into the chain fabric formed by this chain knitted fabric yarn, each of the insert yarns knitted into these chain fabrics, Each of the chain structures is swung outwardly at a certain course, and one or more reinforcing fiber bundles are spaced apart and knitted into a chain structure parallel to the side. And sandwiching both sides of the reinforcing fiber bundle, inserting a low melting point polymer yarn along the longitudinal direction of the sheet material, and fusing at the intersection of the auxiliary insertion yarn, Since it is integrated with the auxiliary warp knitted fabric,
Not only can a suitable shape stability be obtained, but the reinforcing fiber bundle is appropriately restrained by the warp knitted fabric, so that it can move freely and has excellent formability even when molding FRP with many curved surfaces. Further, the meandering of the reinforcing fiber bundle in the sheet due to the shrinkage of the chain knitted fabric yarn or the difference in the path between the outer surface and the inner surface of the sheet in the roll can be prevented.

  More specifically, a polymer adheres to the surface of the chain knitted fabric yarn and a part of the surface of the insertion yarn, and the polymer is melted by heat treatment to fuse the chain knitted fabric yarn and the insertion yarn. Therefore, the reinforcing fiber bundle and the insertion yarn are loosely contacted (referred to as being in contact with each other without being fixed to each other), and the reinforcing fiber bundle is sandwiched with clearance so as to be relatively slidable in the longitudinal direction of the sheet. As a result, the bending history of the reinforcing fiber bundle can be prevented from remaining, and the meandering of the reinforcing fiber bundle in the sheet can be prevented.

  Thus, in the reinforcing fiber sheet material of the present invention, the warp knitted fabric shrinks in the longitudinal direction of the sheet because the polymer adheres to the chain knitted fabric yarn and the warp knitted fabric and the reinforcing fiber bundle are not fused together. Even if it does not affect the reinforcing fiber bundle. Therefore, a sheet material in which the reinforcing fiber bundle does not meander is obtained.

  Further, since the insertion yarn and the reinforcing fiber bundle are not bonded, the reinforcing fiber bundle can move freely in the warp knitted fabric, and thus has excellent shapeability.

  In addition, when the FRP having a large curved surface is molded, the sheet material of the present invention is excellent in formability and hardly wrinkled when laminated on a mold, so that it is very easy to install.

  Furthermore, since a polymer is adhered to at least one side of the reinforcing fiber bundle in parallel with the reinforcing fiber bundle and the polymer is melted by heat treatment, the sheet obtained by fusing the insertion yarn and the reinforcing fiber bundle is also a chain knitted fabric yarn. The same effect can be obtained with a sheet in which the insertion yarn is fused.

  In other words, since the polymer yarn is inserted and adhered to one side of the reinforcing fiber bundle in parallel with the reinforcing fiber bundle, the reinforcing fiber bundle and the insertion yarn are fused. The adhesion between the bundle and the insertion yarn is not a strong adhesion over the entire width of the flat reinforcing fiber bundle surface, but the adhesion with the insertion yarn across the reinforcing fiber bundle is a point-like partial adhesion.

  Therefore, even if the heat set is insufficient and the chain structure shrinks in the longitudinal direction, the reinforcing fiber bundle and the chain knitted fabric yarn are not bonded, so the reinforcing fiber bundle does not meander, and even if the chain structure shrinks. Even if the reinforcing fiber bundle is affected, the entire reinforcing fiber bundle does not meander, and the few fibers constituting the fiber bundle are fibers at the portion where the reinforcing fiber bundle and the insertion thread are bonded, that is, on the surface of the reinforcing fiber bundle. The strength of the FRP is not reduced by the meandering on the bundle surface.

  In addition, since the attachment with the insertion yarn crossing the reinforcing fiber bundle is a spot-like partial adhesion, even when molding FRP with many curved surfaces, the reinforcing fiber is only enough to meander the few fibers constituting the fiber bundle on the surface of the fiber bundle. Since the bundle can move freely in the warp knitted fabric, it is excellent in formability even when molding FRP with many curved surfaces. Similarly, meandering of the reinforcing fiber bundle in the sheet due to shrinkage of the chain knitted fabric yarn and a path difference between the sheet outer surface and the inner surface in the roll can be prevented.

It is a description front view showing the one aspect | mode (surface) of the sheet material of embodiment of this invention. It is a description front view showing the one aspect | mode (back surface) of the sheet material of embodiment of this invention. It is a description front view showing the one aspect | mode (surface) of the sheet material of embodiment of this invention. It is a description front view showing the one aspect | mode (back surface) of the sheet material of embodiment of this invention. It is a description front view showing the one aspect | mode (surface) of the sheet material of embodiment of this invention. It is a description front view showing the one aspect | mode (back surface) of the sheet material of embodiment of this invention. It is a description front view showing the one aspect | mode (surface) of the sheet material of embodiment of this invention. It is a description front view showing the one aspect | mode (back surface) of the sheet material of embodiment of this invention. It is an electron micrograph showing the cross section which cut | disconnected the FRP formed by laminating | stacking the sheet | seat material (chain knitted fabric thread, insertion thread: 110 dtex) of embodiment of this invention in the sheet | seat width direction. In the embodiment of the present invention, it is an electron micrograph showing the section which cut the FRP formed by laminating the sheet material which used the monofilament thread for the insertion thread in the sheet longitudinal direction. It is an electron micrograph showing the cross section which cut | disconnected FRP formed by laminating | stacking the sheet | seat material (chain knitted fabric yarn, insertion yarn: 22 dtex) of embodiment of this invention in the sheet | seat longitudinal direction. It is an electron micrograph showing the cross section which cut | disconnected FRP formed by laminating | stacking the sheet | seat material (insertion thread: 22 dtex) of embodiment of this invention in the sheet | seat width direction.

  The mode for carrying out the present invention will be described in more detail with reference to the drawings specifically illustrated as follows.

  An embodiment of the present invention will be described with reference to FIGS. In the figure, what is indicated by reference numeral 1 is a reinforcing fiber bundle. This reinforcing fiber bundle 1 has reinforcing fibers bundled in a flat shape in parallel with a required width. The materials used are carbon fiber, glass fiber, and aramid. One or a plurality of types selected from fibers can be used. In addition to these, polyester fiber, polyamide fiber, polyolefin fiber, vinylon fiber, boron fiber, and ceramic fiber can be selected as the material used.

  Further, what is indicated by reference numeral 2 is a chain knitted fabric yarn constituting a warp knitted fabric. The chain knitted fabric yarn 2 includes polyester fiber, polyamide fiber, polyolefin fiber, vinylon fiber, glass fiber, aramid fiber and polysulfone. A high-melting-point or high-tensile fiber such as a fiber can be used, and a material having a function such as conductivity, moisture absorption / release, or antibacterial property, or a metal wire can be used as necessary. Moreover, the thread | yarn which consists of a thermoplastic resin material (for example, polyhydroxy ether etc.) fuse | melted with an epoxy resin is also employable.

  Further, what is indicated by reference numeral 3 is an auxiliary insertion yarn constituting a warp knitted fabric, and this auxiliary insertion yarn 3 is adopted from those listed as the material of the chain knitted fabric yarn 2.

  In addition, what is indicated by reference numeral 4 is a polymer yarn, which facilitates continuous heat treatment in the sheet manufacturing process, and does not adversely affect the coupling agent or sizing agent adhering to the surface of the reinforcing fiber. From the viewpoint of reducing the melting point, a low melting point polymer having a melting point of about 80 ° C. to 150 ° C. is preferable. As the low melting point polymer, polyester type, polyamide type, polyacrylonitrile type, and polyolefin type are preferable, and among them, copolymer nylon that can provide strong adhesive force even in a small amount is preferable. These polymer materials are used after being spun into a yarn.

  Therefore, the present invention passes through a reinforcing fiber bundle (in this embodiment, 12,000 filaments, 800 tex carbon fibers) 1 · 1... The reinforcing fiber sheet material of the present invention, which is knitted using a knitting machine and held integrally, will be described below.

  First, the warp knitted fabric has a plurality of rows of chain structures W · W arranged along a predetermined wale interval (for example, six per inch or 4.2 mm pitch) between the reinforcing fiber bundles 1 and 1. And a supplementary insertion yarn 3 knitted in the chain structure W formed by the chain knitted fabric yarn 2.

  Then, the insertion yarns 3 knitted in these chain structures W · W are shaken outward for every predetermined course, and the single or plural reinforcing fiber bundles 1 are spaced apart and parallel to the side. The chain structures W are entangled, and these chain structures W · W are connected to each other in a subtracted state to sandwich both surfaces of the reinforcing fiber bundle 1.

  Then, the low melting point polymer yarn 4 is inserted along the longitudinal direction of the sheet material, and fused at the intersection of the auxiliary insertion yarn 3, so that the reinforcing fiber bundle 1 and the auxiliary yarn warp knitted fabric are integrated. Yes.

  In the present embodiment, the low melting point polymer yarn 4 is inserted along the longitudinal direction of the reinforcing fiber bundle 1, and at least in contact with a part of the surface of the auxiliary insertion yarn 3, the polymer yarn 4 is melted by heat treatment. By fusing the reinforcing fiber bundle 1 and the auxiliary insertion thread 3 in the form of dots, the reinforcing fiber bundle 1 and the insertion thread 3 are loosely contacted (referred to as being in contact with each other without being fixed to each other). As a result, the reinforcing fiber bundle 1 is sandwiched.

  In this embodiment, the composite yarn obtained by coating the polymer yarn 4 on the chain knitted fabric yarn 2 and the insertion yarn 3 are integrally knitted, and the polymer yarn 4 is fused to the chain knitted fabric yarn 2 by heat treatment. To fix the tissue.

  At this time, it is preferable that the polymer yarn 4 is knitted into the chain structure W by inserting one needle, and the chain knitted fabric 2 and the insertion thread 3 of the chain structure W are knitted integrally (see FIGS. 1 and 2). ). By doing so, the polymer yarn 4 passes between the loops and is arranged almost linearly with respect to the longitudinal direction of the sheet, so that the chain structure W of the warp knitted fabric is reliably contracted in the longitudinal direction of the sheet. Can be suppressed.

  Further, as a method for inserting the polymer yarn 4, the polymer yarn 4 and the chain knitted fabric yarn 2 may be aligned together to knit the chain structure, or the aligned yarn may be twisted to knit the chain structure. (See FIGS. 3 and 4), and the polymer yarn 4 can be fused to the chain knit fabric yarn 2 by heat treatment to fix the structure.

  Furthermore, in the present embodiment, the polymer yarn 4 is inserted into the chain structure with the polymer yarn 4 attached along all the chain structures W, or inserted into the chain structure at intervals of a plurality of chain structures. Can do. When the polymer yarn 4 is inserted into all chain structures, the polymer component increases, so that the fineness of the polymer yarn 4 can be appropriately changed.

  Further, when the polymer yarn 4 is inserted into all the chain structures W, the insert yarns 3 and the chain structures W existing in all the chain structures W can be fused, and the insert yarns 3 are formed in the warp knitted fabric. Since the expansion and contraction is restrained by being fixed, the portion does not extend when pulled in the sheet width direction, and the form in the width direction can be stabilized.

  In this case, if the ratio of the polymer component other than the reinforcing fiber is too large with respect to the entire sheet, Vf becomes low when FRP is used, which is not preferable. Moreover, since there are many polymer components with low heat-resistant temperature, there exists a possibility that heat resistance may become low, Therefore By inserting the insertion thread | yarn 3 in the chain | strand structure W at intervals of several, polymer components other than a reinforcement fiber can be decreased. By doing so, a reduction in heat resistance can be reduced.

  If the interval at which the polymer yarn 4 is inserted into the chain structure W is too wide, there are many places where the insertion thread 3 can move freely in the chain structure W, and the stability in the sheet width direction will deteriorate. Further, when the sheet is cut, the chain structure W that is not fused with the polymer yarn 4 contracts in the vicinity of the cut surface, and the reinforcing fiber bundle 1 is exposed and the handleability is deteriorated. It is advisable to select whether to insert all the chain structures W into the chain structure W with a plurality of intervals.

  In the case where the polymer yarn 4 is inserted into the chain structure W with a plurality of intervals, it is preferable to fuse the chain structure W at intervals of 1 to 10, and the interval at this time is not necessarily regular and constant. It is not necessary to fuse with an interval, and it may be irregular.

  1 to 4, the embodiment in which the polymer yarn 4 is inserted into the chain structure W as the warp knitted fabric and the polymer yarn 4 is fused to the insertion yarn 3 has been described. The polymer yarn 4 is inserted into the reinforcing fiber bundle 1 in parallel on the surface of the flat reinforcing fiber bundle 1 without inserting the wire, and the polymer yarn 4 is melted by heat treatment and fused to the insertion yarn 3 in the form of dots. (See FIGS. 5 to 8).

  The position of the reinforcing fiber bundle 1, the polymer yarn 4 and the insertion yarn 3 in the sheet is such that the reinforcing fiber bundle 1, the polymer yarn 4 and the insertion yarn 3 are in the order of the thickness direction of the sheet. 4 is inserted between the reinforcing fiber bundle 1 and the insertion yarn 3, and is restrained by the reinforcing fiber bundle 1 and the insertion yarn 3, so that the position of the polymer yarn 4 with respect to the reinforcing fiber bundle 1 is stabilized, which is preferable.

  Further, as shown in FIGS. 5 and 6, the polymer yarn 4 is inserted into the reinforcing fiber bundle 1 so as to be positioned substantially along the center of the surface of the reinforcing fiber bundle 1, and is heated and fused. can do. At this time, the polymer yarn 4 may be double-sided or single-sided.

  7 and 8, the polymer yarn 4 can be inserted so as to be positioned at the end of the surface of the reinforcing fiber bundle 1, and when the polymer yarn 4 is melted by the heat treatment, the reinforcing fiber bundle It is also possible to partially adhere the polymer yarn 4 to the chain knitted fabric yarn 2 adjacent thereto.

  In the present embodiment, the fineness of the polymer yarn 4 is 10 in order to fuse the chain structure W and the insertion yarn 3 in the chain structure W to prevent shrinkage of the warp knitted fabric and to provide stability in the sheet width direction. It is preferable to be in the range of ~ 120 dtex.

  This is because if the fineness is too thin, adhesion to the chain structure W and the insertion yarn 3 is insufficient, and the yarn strength is low, so that yarn breakage is likely to occur when knitting, and the operability is also deteriorated.

  On the other hand, if the fineness is too thick, the sheet material has a large amount of polymer components other than the reinforcing fibers, Vf when FRP is used, and heat resistance is reduced.

  Next, the polymer yarn 4 is melted by heat treatment and fused to the chain knitted fabric yarn 2 and the insertion yarn 3, respectively, and these two members are fixed. This heat treatment can be performed, for example, by heating with a dry heat far infrared heater or the like for a heating time of 10 seconds to 20 seconds.

  By doing so, contraction in the longitudinal direction in the chain structure W can be substantially prevented. The reinforcing fiber bundle 1 and the insertion yarn 3 are in loose contact with each other, and the reinforcing fiber bundle 1 is curved in a longitudinal direction of the sheet so as to be relatively slidable so as to be curved. It is possible to prevent the history from remaining. When the polymer yarn 4 is melted, it may slightly adhere to the end portion of the adjacent flat reinforcing fiber bundle 1, but the reinforcing fiber against the shrinkage of the reinforcing fiber bundle 1 and chain structure W in the warp knitted fabric. The end of the bundle 1 is only slightly meandering, and does not cause a big problem.

  Further, since the sheet material of the present invention is structured by continuously arranging the polymer yarns 4 in the chain structure W, the polymer yarns 4 can be fused to the entire chain structure W. Therefore, in the knitting process, the chain knitted fabric yarn 2 and the insertion yarn 3 tend to return to the original straight shape due to tension or winding tension, or the loop tends to be rounded. However, the polymer yarn 4 can fuse | bond the whole chain structure W, and can prevent it.

  That is, shrinkage of the warp knitted fabric in the longitudinal direction of the sheet can be suppressed, and further, the reinforcing fiber bundle 1 is prevented from meandering because the reinforcing fiber bundle 1 and the warp knitted fabric are not fixed integrally. It can be done.

  Further, the fineness of the chain knitted fabric yarn 2 and the insertion yarn 3 forming the warp knitted fabric has a large effect on the physical properties when FRP is used, and therefore it is preferably 10 to 90 dtex, and the thickness within such a range. By knitting with the chain knitted fabric yarn 2, the chain structure W can be prevented from contracting in the longitudinal direction.

  In addition, when laminating | stacking sheet | seat materials and shape | molding FRP, an epoxy resin, vinyl ester resin, unsaturated polyester resin, a phenol resin, etc. can be used.

  If the chain knitted fabric yarn 2 and the insertion yarn 3 are too thick, the chain structure W formed by the chain knitted fabric yarn 2 and the insertion yarn 3 protrudes from the surface of the sheet in the thickness direction, and the apparent sheet thickness increases. In addition, since the proportion of the chain structure W between the reinforcing fiber bundles 1 increases, the volume of the resin reservoir (resin rich) in which only the resin component exists when molded is increased, and the Vf of the FRP is reduced. FRP with excellent mechanical characteristics cannot be obtained (see FIG. 9). Therefore, it is preferable to form the chain structure W with the chain knitted fabric yarn 2 and the insertion yarn 3 of 10 to 90 dtex.

  In addition, when the insertion thread 3 is too thick, when a plurality of sheet materials are laminated to form the FRP, a thick insertion thread exists partially between the sheet layers, so that the portion becomes thick and the apparent sheet thickness is reduced. Become thicker. Therefore, a gap that becomes rich in resin in the thickness direction is increased.

  That is, the thicker the insertion thread 3 is, the larger the volume of the resin rich between the layers becomes, and the Vf is lowered, or when pressure is applied in the thickness direction when molding is performed by laminating the reinforcing fiber sheet material and impregnating the resin. The reinforcing fiber meanders in the thickness direction at the place where the insertion yarn 3 is present (see FIG. 10), and the thicker the insertion yarn 3 is, the local meandering occurs. Therefore, the stress concentration when a load is applied by configuring the FRP In the same manner, FRP having excellent mechanical properties cannot be obtained.

  On the contrary, if the chain knitted fabric yarn 2 and the insertion yarn 3 are too thin, yarn breakage is likely to occur when the reinforcing fiber sheet material is knitted, and knitting becomes difficult.

  For this reason, it is preferable to form the chain structure W with the chain knitted fabric yarn 2 and the insertion yarn 3 of 10 to 90 dtex (see FIG. 11).

  Moreover, even when the fineness is the same, when multifilaments in which a plurality of filaments are aligned are used, when the sheets are laminated, each filament spreads and becomes a flattened shape that spreads flatly (FIG. 12). See), and the apparent sheet thickness can be reduced.

  And in this embodiment, the thermoplastic resin yarn melt | dissolved in an epoxy resin can be employ | adopted as the chain-knitted fabric yarn 2 and the auxiliary insertion yarn 3 which are used for a sheet material.

  That is, when molding FRP, a laminate of reinforcing fiber sheets is mainly impregnated with an epoxy resin and cured. Accordingly, by using such a meltable yarn, when the epoxy resin is impregnated, the chain knitted fabric yarn 2 and the auxiliary insertion yarn 3 are melted and lost. The insertion thread 3 does not exist. When the chain knitted fabric yarn and the auxiliary insertion yarn are thus melted, the auxiliary insertion yarn 3 between the layers of the laminated sheet material is eliminated, so that an appropriate resin-rich space is formed, and the reinforcing fiber due to the presence of the reinforcing insertion yarn 3 The local meandering (see FIG. 10) can be prevented.

  Further, since the chain structure W existing between the reinforcing fiber bundles 1 is also eliminated, the reinforcing fiber bundles 1 are more uniformly dispersed in the molded product by the pressure during molding, and local Vf variation can be reduced. Therefore, it is possible to obtain an FRP with a small variation in mechanical characteristics.

  Next, the shrinkage amount due to the heat treatment of the sheet material in the present embodiment will be described. This amount of shrinkage is greatly affected by the “dry heat shrinkage rate” of the chain knitted fabric yarn 2 and the insertion yarn 3 and the fineness of the yarn. The greater the dry heat shrinkage rate, the greater the amount of shrinkage due to heat treatment. Even if the dry heat shrinkage rate is the same, the greater the fineness of the yarn, the greater the force of shrinkage due to heat treatment. That is, the shrinkage phenomenon tends to occur because the shrinkage rate increases as the dry heat shrinkage rate increases and the fineness of the yarn increases.

In addition, the dry heat shrinkage in this embodiment is based on the following measuring methods.
(1) Conforms to JIS L 1013 dry heat shrinkage (method B).
(2) Initial load is 2.94mN x yarn fineness (tex)
(3) Heating temperature is 180 ° C
(4) Heating time is 30 minutes (5) Heat shrinkage ratio [%] = (length before heating−length after heating) ÷ (length before heating) × 100

  In the sheet material of the present invention, the warp knitted fabric is made into a sheet by reducing the dry heat shrinkage rate of the chain knit fabric yarn 2 and the insertion yarn 3 and reducing the shrinkage force due to heat by using a thinner yarn. The shrinkage in the longitudinal direction can be suppressed, the reinforcing fiber bundle 1 can be prevented from meandering, and a high-strength sheet material can be obtained.

  In addition, adopting such a yarn having a low dry heat shrinkage rate means that the basis weight difference between the center and both ends of the sheet width direction is suppressed by suppressing shrinkage of the warp knitted fabric in the sheet width direction due to heat treatment. This also contributes to the achievement of the goal of making the size smaller.

  Therefore, it is possible to obtain a sheet material in which variations in strength and thickness are reduced in the sheet width direction, the thickness becomes uniform as a whole when the sheet materials are laminated, and the FRP is impregnated with a resin. Is preferable because the variation in strength becomes small.

  Moreover, in this embodiment, since the shrinkage | contraction by heat processing becomes so small that the dry heat shrinkage rate of the chain knit fabric yarn 2 and the insertion yarn 3 is as small as possible, dry heat shrinkage rate is 4.0% or less (more preferably 1). .5% or less). A comparative example using the boundary condition of about 4.0% yarn will be described later.

  The chain knitted fabric yarn 2 and the insertion yarn 3 in this embodiment are, for example, water obtained by heating a relatively low shrinkage yarn having a dry heat shrinkage rate of 3 to 4%, which is a polyester fiber yarn, to 100 ° C. or higher with a high-temperature high-pressure kettle. It can be obtained by processing it on

  Further, in order to obtain an auxiliary yarn having a dry heat shrinkage rate of 1.5% or less, it is not always necessary to perform heat treatment in a wet manner, and a dry heat treatment may be employed. Further, the type of yarn used may be synthetic fiber other than polyester fiber, or may be glass fiber yarn having a very low dry heat shrinkage rate. In the case of glass fiber yarn, the productivity is slightly inferior, but since the dry heat shrinkage rate is almost zero, the difference in basis weight between the central portion and both end portions in the sheet width direction becomes very small, and a uniform sheet material can be obtained.

  The present invention is generally configured as described above. However, the present invention is not limited to the illustrated embodiment, and various modifications are possible within the description of “Claims”. The material used can be appropriately changed according to the application.

  Using the following materials, 130 reinforcing fiber bundles and chain knitted fabric yarn are arranged so that the wale interval is 4.2 mm pitch, the insertion yarn is shaken at a pitch of 6 mm, and the polymer yarn 4 is 1 in the chain structure W. The sheet material of the present invention (hereinafter referred to as “Example 1”) was produced by knitting by needle insertion, melting the polymer by heat treatment, and bonding the chain knitted fabric yarn and the insertion yarn.

<Material conditions of Example 1>
Reinforced fiber bundle: 800 tex made of 12,000 multifilaments, carbon fiber bundle of 1% by weight of sizing, chain knitted fabric yarn: polyester fiber yarn made of 22 decitex multifilaments, with a dry heat shrinkage of 0 .6%
Insert yarn: Polyester fiber yarn consisting of 22 decitex multifilament with 0.6% dry heat shrinkage
Polymer yarn; multifilament yarn made of copolymerized nylon resin with a fineness of 33 dtex

  On the other hand, the same reinforcing fiber bundle, chain knitted fabric yarn, insertion yarn and polymer yarn as in Example 1 were used, and the polymer yarn was coated (covering) on the insertion yarn, and the other production conditions were the same as in Example 1. A sheet material was produced (Comparative Example 1).

  As another comparative example, a polyester fiber yarn composed of 22 dtex multifilament was used as the insertion yarn, and the yarn had a dry heat shrinkage of 10%. The insertion yarn was covered with a polymer yarn (covering). Other manufacturing conditions were the same as in Example 1, and a sheet material was produced (Comparative Example 2).

  Then, the thickness of each sheet material measured with a micrometer, the width of the sheet material, and the warp knitted fabric of the standard length sheet material are disassembled, the reinforcing fiber bundle is taken out and stretched straight with appropriate tension The length of the reinforced fiber bundle was measured, and the yarn length calculated from [(reinforced fiber bundle length after decomposition) − (reference length)] / (reference length) × 100 = (ratio of yarn length difference) The ratio of the difference, and further, the difference between the basis weight of the central portion of the sheet material and the basis weight of the outermost edge portion was taken as the basis weight difference, and the results measured from the distance between the six chain structures at each measurement location and the amount of reinforcing fiber are shown in the following [Table 1 ]. The ratio of the yarn length difference indicates the degree of meandering of the reinforcing fiber bundle in the sheet material. Further, the basis weight difference indicates the uniformity of the basis weight in the width direction of the sheet material, that is, the smaller the basis weight difference, the more uniform the basis weight.

  Regarding the thickness of the sheet material, the thickness of the sheet material of Example 1 was almost the same as the thickness of the reinforcing fibers. In the sheet material of Comparative Example 1, since the polymer was covered with the insertion yarn, the thickness of the entire insertion yarn became thick, and when the heat treatment was performed, the entire insertion yarn became a monofilament yarn, and the thickness of the sheet material was increased. It was thicker than the sheet material of Example 1. Further, with respect to Comparative Example 2, the reinforcing fiber bundle became denser and the basis weight increased due to the large shrinkage of the width, so that the thickness became thicker.

  Further, with respect to the width of the sheet material, there was almost no difference between Example 1 and Comparative Example 1, and the basis weight distribution was almost uniform. However, since Comparative Example 2 used an insertion yarn having a higher dry heat shrinkage than Example 1 and Comparative Example 1, the shrinkage force in the width direction was increased by the heat treatment, and the width of the sheet material was reduced. In particular, the shrinkage at the outermost edge portion of the sheet material was large, and the basis weight difference between the central portion of the sheet material and the outermost edge portion was also larger than that in Example 1.

  Regarding the ratio of the yarn length difference, Example 1 had a smaller ratio of the yarn length difference than that of Comparative Example 1 and Comparative Example 2, and the meandering of the reinforcing fiber bundle was small. Also in appearance, the sheet material of Example 1 had smaller reinforcing fiber meanders than the comparative example.

  Next, a sample of 35 cm × 35 cm is cut out from the center in the width direction of each of the above sheet materials, five sheets are laminated so that the reinforcing fibers are in the same direction in the molding die, the top is covered with a film, Then, after impregnating a liquid vinyl ester resin at room temperature, the resin was heated and cured to prepare an FRP plate.

  The thickness of the FRP plate and the tensile strength, the tensile elastic modulus and the Vf measured according to JIS K7075, which are representative values of mechanical properties in the reinforcing fiber arrangement direction of the FRP plate measured according to JIS K7165, and Example 1 Table 2 below shows the values of tensile strength and tensile modulus obtained by converting the fiber volume content to 100% in Vf of Comparative Example 1.

  Regarding the thickness of the FRP plate, the FRP using the sheet material of Example 1 was thicker than the FRP using the sheet material of Comparative Example 1. This is because, in the sheet material of Comparative Example 1 compared to the sheet material of Example 1, when a plurality of sheet materials are stacked and an FRP is formed, the insertion yarn is partially covered between the sheet layers by covering the polymer yarn. Since a thick insertion thread is present, the portion becomes thick and the apparent sheet thickness increases. Therefore, the gap that becomes rich in the resin in the thickness direction is increased, and the thickness when the resin is impregnated to make the FRP is increased accordingly.

  Also, the VRP of the FRP plate was larger in the FRP using the sheet material of Example 1 than in the FRP using the sheet material of Comparative Example 1.

  Furthermore, the tensile strength / elastic modulus of the FRP using the sheet material of Example 1 is larger than that of the FRP using the sheet material of Comparative Example 1, but converted to 100% considering the Vf value. Also in terms of value, the sheet material of Example 1 is superior to Comparative Example 1.

  Next, with respect to the optimum dry heat shrinkage (4.0% or less) of the chain knitted fabric yarn 2 and the insertion yarn 3 in this embodiment, a comparative example using a yarn of around 4.0% which is this boundary condition Is described below.

  First, as Example 2, a 22 dtex multifilament yarn having a dry heat shrinkage of 2.5% was used as the chain knitted fabric yarn 2 and the insertion yarn 3. The other conditions were the same as in Example 1 to produce a sheet material.

  Further, as Comparative Example 3, a 22 dtex multifilament yarn having a dry heat shrinkage rate of 5.0% was used as the chain knitted fabric yarn 2 and the insertion yarn 3. The other conditions were the same as in Example 1 to produce a sheet material.

  The following Table 3 shows the results of measuring the width of each sheet material, the ratio of the yarn length difference, the sheet material center area weight, the sheet material end edge area weight, and the weight difference.

  The thickness of the sheet material is almost the same as the thickness of the reinforcing fibers, and the sheet material of Comparative Example 3 is denser as the reinforcing fiber bundle 1 becomes dense because the width is slightly contracted compared to Example 1. Because of the increase in thickness, the thickness became slightly thicker.

  On the other hand, the width of the sheet material of Example 2 was slightly smaller than that of Comparative Example 3 as compared with Example 1, but almost no difference in thickness occurred.

  Moreover, about the width | variety of the sheet | seat material, the width | variety became narrow in order of Example 1> Example 2> Comparative Example 3, and the tendency for the width | variety to shrink | contracted appeared. This is because the dry heat shrinkage of the chain knitted fabric yarn 2 and the insertion yarn 3 used is large in the order of Example 1 <Example 2 <Comparative Example 3, and if the dry heat shrinkage is large, shrinkage in the width direction due to heat treatment is caused. This is because it becomes larger.

  At this time, the shrinkage at the outermost edge portion of the sheet material was particularly large, and the difference in basis weight between the central portion of the sheet material and the outermost edge portion of the sheet material showed almost no difference between Example 1 and Example 2. Comparative Example 3 was larger than Example 1.

  Further, regarding the ratio of the yarn length difference, there was almost no difference between Example 1 and Example 2, but Comparative Example 3 was larger than Example 1. The polymer yarn 4 inserted into the chain structure W is bonded to the chain knitted fabric yarn 2 and the insertion yarn 3 to suppress shrinkage in the longitudinal direction of the warp knitted fabric. This is because when the dry heat shrinkage rate of the yarn 3 is large, a large heat shrinkage history during the heat treatment remains.

<Example of preform molding>
Next, the specific example which shape | molds a preform using the reinforcing fiber sheet material of this invention is demonstrated below. First, the sheet material of Example 1 is cut into a length of 300 mm and a width of 150 mm, and laminated in one direction so that the orientation directions of the reinforcing fibers are the same direction.

  Then, the laminated product is put into a vacuum bag with a suction port made of a sealant and a bag film, and the pressure is reduced from the suction port and is kept at 130 ° C. while applying atmospheric pressure for 10 minutes. After leaving it, it was taken out to complete Preform A.

  Next, a sheet material (Comparative Example 4) manufactured under the same conditions as in Example 1 except that no polymer yarn is used is prepared. Using the sheet material of Comparative Example 4, the preform A and Preform B was completed under similar manufacturing conditions.

  Also, using the same carbon fiber as the sheet material of Example 1, both the warp yarn and weft yarn spacings composed of 56 dtex polymer yarns from both sides of the sheet with the carbon fibers aligned in one direction without gaps are both After combining the meshes arranged at 10 mm intervals, the carbon fiber sheet and the mesh are bonded by heat treatment to align them in one direction to complete an integrated sheet material (Comparative Example 5). Using the sheet material of Comparative Example 5, Preform C was obtained under the same production conditions as Preform A.

  The preforms A to C thus obtained were impregnated with a resin, the flow rate of the resin was observed, and the impregnation property was evaluated. Specifically, a film bag is formed around the preform, and a resin having a viscosity of 1.0 poise is impregnated at 60 ° C. while vacuuming (−0.1 MPa) inside the bag by a vacuum pump, and the resin flows 20 cm. The time taken was measured.

  At this time, the mold temperature, the room temperature, and the resin temperature are 60 ° C., the sheet longitudinal direction of the laminated sheet material is the resin flow direction, the resin inlet at one end of the sheet material longitudinal direction, and the resin suction at the other one end Mouth set up. The results are shown in [Table 4] below.

  As for the handling properties, the preform A and the preform C are integrated in the process of obtaining the preform by melting the polymer yarn when heated, and bonding the strands of the laminated layers or warp knitted fabrics together. Therefore, each layer did not vary during handling, and the handleability as a preform was good.

  On the other hand, since the preform B has no polymer yarn, the layers are not bonded and integrated, and therefore, each layer is scattered during handling, and the handleability as a preform is poor.

  As for the resin impregnation property, in the sheet materials of Example 1 and Comparative Example 4 used for the preform A and the preform B, a chain structure W exists between the reinforcing fiber bundles, and this chain structure W is Since the structure is three-dimensional and there are gaps in the structure, the resin easily flows and the impregnation time of the resin is faster than that of the preform C.

  On the other hand, in the sheet material of Comparative Example 5 used for the preform C, the reinforcing fiber bundles are aligned, so that there is no gap between the reinforcing fiber bundles and the resin is difficult to flow. Not impregnated.

  As described above, when forming the FRP using the sheet material of the present invention by forming the chain knitted fabric yarn 2 and the auxiliary insertion yarn 3 in the sheet material into thermoplastic resin yarns that melt into the epoxy resin, as a preform Can be further improved.

DESCRIPTION OF SYMBOLS 1 Reinforcing fiber bundle 2 Chain knitted fabric yarn 3 Auxiliary insertion yarn 4 Low melting point polymer yarn W Chain structure

Claims (12)

The reinforcing fiber bundles 1.1,.
The auxiliary yarn warp knitted fabric includes a chain knitted fabric yarn 2 forming a plurality of rows of chain structures W · W arranged along a predetermined wale interval between the reinforcing fiber bundles 1 and 1, and the chain knitted fabric. While composed of the auxiliary insertion yarn 3 knitted into the chain structure W formed by the yarn 2,
Each of the auxiliary insertion yarns 3 knitted into these chain structures W · W is swung to the outside for every fixed course, and one or a plurality of reinforcing fiber bundles 1 are spaced apart and parallel to the side. The chain structure W is knitted, and the chain structures W and W are connected to each other in a subtracted state to sandwich both surfaces of the reinforcing fiber bundle 1,
The low melting point polymer yarn 4 is inserted along the longitudinal direction of the sheet material,
A reinforcing fiber sheet material in which the reinforcing fiber bundle 1 and the auxiliary yarn warp knitted fabric are integrated by fusing at the intersection of the auxiliary insertion yarns 3.   The low-melting polymer yarn 4 is inserted along the longitudinal direction of the reinforcing fiber bundle 1, and at least comes into contact with a part of the surface of the auxiliary insertion yarn 3, and the polymer yarn 4 is melted by heat treatment to reinforce the reinforcing fiber bundle 1. And the auxiliary insertion yarn 3 are fused in a dot shape so that the reinforcing fiber bundle 1 and the insertion yarn 3 are in loose contact with each other, and the reinforcing fiber bundle 1 is sandwiched. The reinforcing fiber sheet material described.   The composite yarn formed by coating the low-melting polymer yarn 4 on the chain-knitted fabric yarn 2 and the auxiliary insertion yarn 3 are knitted integrally, and the low-melting-point polymer yarn 4 is fused to the chain-knitted fabric yarn 2 by heat treatment. The tissue is fixed, The reinforcing fiber sheet material according to claim 1 or 2.   The low melting point polymer yarn 4 is knitted into the chain structure W by inserting one needle, and the chain knitted fabric yarn 2 and the auxiliary insertion yarn 3 of this chain structure W are knitted integrally, and the low melting point polymer yarn 4 is subjected to heat treatment. The reinforcing fiber sheet material according to any one of claims 1 to 3, wherein the structure is fixed to the chain-knitted fabric yarn 2 by being fused.   The low-melting polymer yarn 4 and the chain knitted fabric yarn 2 are drawn together and knitted together with the auxiliary insertion yarn 3, and the low-melting polymer yarn 4 is fused to the chain knitted fabric yarn 2 by heat treatment to fix the structure. The reinforcing fiber sheet material according to any one of claims 1 to 3, wherein the reinforcing fiber sheet material is used.   The reinforcing fiber sheet material according to any one of claims 1 to 5, wherein the low-melting-point polymer yarns 4 are attached along all the chain structures W.   The reinforcing fiber sheet material according to any one of claims 1 to 6, wherein the low-melting polymer yarn 4 has a fineness of 10 to 120 dtex.   The fineness of the chain knitted fabric yarn 2 and the auxiliary insertion yarn 3 is 10 to 90 dtex, and the chain knitted fabric yarn 2 is knitted to prevent shrinkage of the chain structure W in the longitudinal direction. The reinforcing fiber sheet material according to any one of 1 to 7.   The dry heat shrinkage ratio (JIS L 1013 (Method B)) of the chain-knitted fabric yarn 2 and the auxiliary insertion yarn 3 is 4.0% or less, according to any one of claims 1 to 8. Reinforced fiber sheet material.   The reinforcing fiber sheet material according to any one of claims 1 to 9, wherein the chain knitted fabric yarn 2 and the auxiliary insertion yarn 3 are multifilament yarns.   The reinforcing fiber sheet material according to any one of claims 1 to 10, wherein the reinforcing fibers of the reinforcing fiber bundle 1 are composed of one or more of carbon fibers, glass fibers, and aramid fibers.   The reinforcing fiber sheet material according to any one of claims 1 to 11, wherein the chain-knitted fabric yarn 2 and the auxiliary insertion yarn 3 are thermoplastic resin yarns that melt into an epoxy resin.