COMBINED FILAMENT YARN AND MANUFACTURING METHOD THEREOF

Abstract

 The present invention has an object of providing a combined filament yarn having a favorable quality in which a synthetic fiber material is dispersed in and combined with a reinforcing fiber material, and a manufacturing method thereof. In the combined filament yarn, with the reinforcing fiber material arranged in a predetermined direction, the synthetic fiber material arranged in the same direction as that of the reinforcing fiber material is combined, the synthetic fiber material is bonded to and integrated with the reinforcing fiber material, and the synthetic fiber material is dispersed so that a standard deviation relating to a rate of a sectional area of the synthetic fiber material in a divided region obtained by dividing a section of the combined filament yarn becomes 25 or less.

Description

Technical Field

[0001] The present invention relates to a combined filament yarn in which a reinforcing fiber material such as a carbon fiber and a synthetic fiber material such as a thermoplastic resin are combined, and to a manufacturing method thereof.

Background Art

[0002] The fiber reinforced composite material is obtained by combining a fiber material and a matrix material and is a light-weighted and highly rigid material capable of diversified functional designs and used in a wide variety of fields such as aerospace, transport, civil engineering and construction, and exercise tools. At present, a fiber reinforced plastic (FRP) in which a reinforcing fiber material such as a carbon fiber or a glass fiber is combined with a synthetic resin material such as a thermosetting resin material or a thermoplastic resin material has become mainstream. In the FRP, development of molded products by a carbon-fiber reinforced composite material (CFRP; Carbon Fiber Reinforced Plastic) using a carbon fiber as a reinforcing fiber and a thermoplastic resin material as a matrix resin is expected to increase from viewpoints of advantages in recyclability, short-time moldability, improvement of impact resistance of molded products and the like.

[0003] Regarding a fiber reinforced composite sheet material in which the reinforcing fiber material and the synthetic resin material are combined, for example, PTL 1 describes manufacturing a prepreg by overlapping a resin sheet in which a resin is laminated on a mold releasing film, on a fiber body in which the carbon fibers are arranged in one direction and by heating them so as to impregnate the fiber body with a resin. Other than the method of manufacturing the fiber reinforced composite material by overlapping a synthetic resin material which becomes a matrix resin on such a reinforcing fiber material, a method of manufacturing a fiber reinforced composite material by manufacturing a combined filament yarn by combining the synthetic fiber material obtained by fiberizing the synthetic resin material which becomes the matrix resin and the reinforcing fiber material and by using the obtained combined filament yarn is proposed (see NPL 1).

Citation List

Patent Literature

[0004] PTL 1: Japanese Patent Laid-Open No. 2009-91377

Non Patent Literature

[0005] NPL 1: "Trial production and physical characteristic evaluation of thermoplastic carbon fiber reinforced composite material using commingled yarn" by Hiroyuki Hasebe and two others, pp. 11 to 12, Lecture abstracts, Hokuriku Branch, the Textile Machinery Society of Japan

Summary of Invention

Technical Problem

[0006] In PTL 1, since a resin sheet is overlapped with a fiber body so as to be impregnated with a resin, the resin does not penetrate between the fibers easily, and voids can be easily generated. Moreover, a manufacturing process of a resin sheet or the like is required, which increases the number of processes, and increases in a size of manufacturing facilities and facility costs cannot be avoided. Furthermore, in the method of using the combined filament yarn in which the synthetic fiber material is combined with the reinforcing fiber material, since the combined filament yarn in which the synthetic fiber material is arranged within the reinforcing fiber material in advance is used, the resin can penetrate in the reinforcing fiber material more easily than in the method described in PTL 1, and occurrence of voids is suppressed.

[0007] In the methods using such combined filament yarns, those in which the synthetic fiber material is combined with the reinforcing fiber material as uniformly as possible need to be used. Such prior-art combined filament yarns include those in which a sheath yarn is wound around a core yarn by covering, but in such combined filament yarns, the reinforcing fiber material and the synthetic fiber material are separated in two layers, and it is difficult to bring about a uniformly combined state.

[0008] Moreover, in NPL 1, a carbon fiber and a synthetic fiber made of polyphenylenesulfide (PPS) are overlapped while being fed out at a constant speed, and the both are interlaced by blowing air by an air nozzle to the overlapped portion so as to combine the fibers. However, in air interlacing by blowing air, it is difficult to sufficiently combine the both, and the carbon fiber is cut during the air interlacing and fuzzes, which results in a problem of difficulty in manufacturing a good-quality combined filament yarn.

[0009] Thus, the present invention has an object to provide a combined filament yarn having a favorable quality in which a synthetic fiber material is dispersed in a reinforcing fiber material and combined therewith, and a manufacturing method thereof.

Solution to Problem

[0010] A combined filament yarn according to the present invention is a combined filament yarn in which, with a reinforcing fiber material arranged in a predetermined direction, a synthetic fiber material arranged in the same direction as that of the reinforcing fiber material is combined, wherein the synthetic fiber material is bonded to and integrated with the reinforcing fiber material, and the synthetic fiber material is dispersed so that a standard deviation relating to a rate of a sectional area of the synthetic fiber material in a divided region obtained by dividing a section of the combined filament yarn becomes 25 or less.

[0011] A manufacturing method of a combined filament yarn according to the present invention includes an overlapping process of overlapping a synthetic fiber material on a sheet-state reinforcing fiber material spread and arranged in a predetermined direction in a state where the synthetic fiber material is arranged in the same direction as that of the reinforcing fiber material and dispersed in accordance with density of the reinforcing fiber material, and an integrating process of bonding and integrating the overlapped reinforcing fiber material and synthetic fiber material. Moreover, in the overlapping process, the overlapped reinforcing fiber material and the synthetic fiber material are subjected to spreading processing. Furthermore, a yarn forming process of forming the bonded and integrated reinforcing fiber material and synthetic fiber material into a yarn in another form is provided.

Advantageous Effects of Invention

[0012] Since the present invention has the constitution as above, a combined filament yarn having a favorable quality in which the synthetic fiber material is dispersed in the reinforcing fiber material and combined therewith can be obtained. When a molded product is to be obtained by using the combined filament yarn of the present invention, a high-quality molded product without a void can be obtained even under a relatively mild molding condition.

Brief Description of Drawings

[0013] 

Fig. 1 is an explanatory diagram relating to a process of manufacturing a combined filament yarn according to the present invention.

Fig. 2 is an explanatory diagram relating to an overlapping process and an integrating process.

Figs. 3(a) to 3(d) are schematic sectional diagrams of the combined filament yarn.

Fig. 4 is a photographed image relating to a section of the combined filament yarn according to Example 1.

Fig. 5 is a photographed image relating to a section of the combined filament yarn according to Example 2.

Description of Embodiments

[0014] An embodiment of the present invention will be described below by using the attached drawings. Note that, since the embodiment described below is a preferred embodiment when the present invention is to be carried out, various technical limitations are made but the present invention is not limited to these forms unless a limitation of the present invention is specified otherwise in the following explanation.

[0015] Fig. 1 is an explanatory diagram relating to a process of manufacturing a combined filament yarn according to the present invention. First, a sheet forming process of forming a reinforcing fiber material and a synthetic fiber material to be raw materials of a combined filament yarn into a sheet state is performed. In the case of the reinforcing fiber material, a fiber bundle is spread and formed into a thin-layer sheet shape. Methods for spreading the reinforcing fiber material include known methods such as a method for spreading the fiber bundle by bringing it into contact with an spreading roller, a vibration roller or the like, a method for spreading the fiber bundle while bending the fiber bundle by causing the fiber bundle to feed so as to cross a flow of a fluid, and a method for spreading the fiber bundle combining them. Particularly, since the method for spreading the fiber bundle while bending the fiber bundle by using the fluid (see Japanese Patent No. 3064019, for example) can uniformly spread the fiber bundle without damaging the reinforcing fiber, it is suitable as the method for spreading the reinforcing fiber material. Moreover, by arranging a plurality of fiber bundles in parallel in a width direction and by applying the spreading processing to them at the same time, it is possible to easily form a wide sheet shape.

[0016] In the case of the synthetic fiber material, those in a state of a fiber bundle can be formed into a thin-layer sheet shape by warping processing using a warping machine or the spreading processing similar to the method for spreading the reinforcing fiber material. Moreover, if the fiber material is to be manufactured by spinning from a synthetic resin material to be a raw material, a thin-layer sheet-state synthetic fiber material can be obtained by spinning in a state where the fiber material is aligned in a sheet state.

[0017] The reinforcing fiber materials include inorganic fibers, organic fibers and the like with high intensity/high modulus of elasticity used in FRP such as a carbon fiber, a glass fiber, a ceramic fiber, an aramid fiber, a PBO (polypara-phenylenebenzobisoxazole) fiber, and a metal fiber, for example. Moreover, a plurality of the fiber bundles in each of which these fibers are bundled may be combined. Here, fineness is not particularly limited.

[0018] As the synthetic fiber material, those to be base (matrix) resins such as polypropylene, polyethylene, polystyrene, polyamide (nylon 6, nylon 66, nylon 12 and the like), polyacetal, polycarbonate, acrylonitrile-butadiene-styrene copolymer (ABS), polyethylene terephthalate, polybutylene terephthalate, LPC (liquid crystal polyester), polyimide, polyether imide, polyether sulfone, polyphenylene sulfide, polyether ketone, and polyetheretherketone are used. Moreover, two kinds or more of these thermoplastic resins may be mixed so as to form a polymer alloy and used as the base (matrix) resin.

[0019] Furthermore, as the synthetic fiber material, a composite fiber material having a melting point on a surface portion lower than that on a center portion can be also used in order to improve adhesiveness with the reinforcing fiber material in an integrating process which will be described later. For example, a composite fiber material having a core-sheath structure in which a synthetic resin material having a high melting point is used as a core portion and a synthetic resin material having a low melting point is used as a sheath portion can be cited. Since such a composite fiber material is used, by heating it at a temperature lower than the melting point of the core portion and higher than the melting point of the sheath portion, it is possible to reliably bond and integrate the sheath portion with the reinforcing fiber material while maintaining a form of the fiber.

[0020] A use amount of the synthetic fiber material may be set in accordance with a use amount of the reinforcing fiber material and can be set on the basis of a volume fraction of fiber (hereinafter abbreviated as a "Vf value") of the fiber reinforced composite material using a combined filament yarn. The fineness of the synthetic fiber material is preferably such that the synthetic fiber material can easily enter between the reinforcing fibers and has durability against tension applied when being handled as the combined filament yarn.

[0021] Subsequently, an overlapping process of overlapping a sheet-state synthetic fiber material on a sheet-state reinforcing fiber material is performed. Fig. 2 is an explanatory diagram relating to the overlapping process and the integrating process. The sheet-state reinforcing fiber material T and the sheet-state synthetic fiber material S are fed in parallel in a state arranged in a predetermined direction and passed between pressure-contact rolls R so as to be set in a state in which the sheet-state synthetic fiber material is brought into pressure-contact and overlapped with one side of the sheet-state reinforcing fiber material.

[0022] The synthetic fiber material S is arranged through adjustment so that it is dispersed in accordance with density of the sheet-state reinforcing fiber material T. For example, if the reinforcing fiber material T is a thin layer and has low density, a plurality of the synthetic fiber materials S is arranged at a predetermined interval and overlapped in accordance with the density. Moreover, if the reinforcing fiber material T has low density or if a Vf value is set high, the reinforcing fiber material T may be overlapped on both sides of the synthetic fiber material S.

[0023] Furthermore, in order for the synthetic fiber material S to enter between the reinforcing fiber materials T, the spreading processing can be performed in an overlapped state as necessary. In Fig. 2, a spreading mechanism K is arranged on a downstream side in a feeding direction of the pressure-contact rolls R, and in the spreading mechanism K, an air flow is made to cross the reinforcing fiber material T and the synthetic fiber material S in the overlapped state so as to bend and spread them while feeding them. The spreading mechanism K may be a mechanism in which a vibration roller and the like are combined. Here, in the spreading processing, a tension applied to the reinforcing fiber material T and the synthetic fiber material S is fluctuated, but if the synthetic fiber material S is more expanded/contracted as compared with the reinforcing fiber material T, by arranging the synthetic fiber material S on the downstream side of a flow of the air flow, fibers of the synthetic fiber material S are expanded/contracted during the spreading processing and easily enter between the reinforcing fibers.

[0024]  As described above, since the synthetic fiber material can be dispersed and overlapped in accordance with the density of the spread reinforcing fiber material, fiber mixing in a more uniform state is made possible. Moreover, the synthetic fiber material can be dispersed in advance in accordance with processing of a yarn forming process which will be described later, and the synthetic fiber material is overlapped so that a combined state of the combined filament yarn to be manufactured in the end becomes uniform.

[0025] Subsequently, the integrating process of integrating the reinforcing fiber material and the synthetic fiber material in the overlapped state is performed. In the example illustrated in Fig. 2, by passing the reinforcing fiber material T and the synthetic fiber material S in the overlapped state between heating rolls H while feeding them, the synthetic fiber material S is provisionally bonded and integrated. When the synthetic fiber material S is to be provisionally bonded, by performing pressure-contact by the heating rolls H, the synthetic fiber material S is partially melted and thermally fused with the reinforcing fiber material T, but the synthetic fiber material S is bonded still in a state where its fiber form is maintained. For example, if the composite fiber material described above is used as the synthetic fiber material S, by setting a temperature of the heating rolls H at a temperature lower than the melting point of the core portion and higher than the melting point of the sheath portion, the sheath portion is thermally fused with the reinforcing fiber material T and they can be integrated while maintaining the fiber form.

[0026] By provisionally bonding the synthetic fiber material to the reinforcing fiber material for integration, the spread reinforcing fiber material does not get loose, whereby handling thereof as a combined filament yarn is facilitated. Moreover, since the reinforcing fiber material and the synthetic fiber material are integrated in the state maintaining the fiber form, tension strength or drape properties can be sufficiently provided in weaving using the combined filament yarn. Here, when the synthetic fiber material is to be provisionally bonded to the reinforcing fiber material, the synthetic fiber material may be bonded entirely or partially as necessary, and a bonded spot may be set to a dot shape, a line shape or a band shape, for example, and it may be set as appropriate in accordance with an application of the combined filament yarn.

[0027] Subsequently, the yarn forming process of finishing the combined filament yarn to yarns in various other forms is performed. Those obtained by the integrating process can be also used as they are as the combined filament yarns, but when a combined filament yarn according to the application is to be manufactured, those obtained by the integrating process are subjected to the yarn forming processing such as twisting, folding, overlapping and slitting so that the combined filament yarns in the various forms can be manufactured. Figs. 3(a) to 3(d) are schematic sectional diagrams of the combined filament yarn. Fig. 3(a) illustrates a sectional diagram of the combined filament yarn obtained by twisting the integrated reinforcing fiber material and synthetic fiber material by a known twisting device. The integrated reinforcing fiber material and synthetic fiber material are formed into a sheet shape and are wound in a width direction by twisting in processing and thus, a state where the synthetic fiber material is dispersed to a center part of the combined filament yarn is brought about and more uniform combined filament yarn can be obtained. Fig. 3(b) illustrates a sectional diagram of the combined filament yarn obtained by folding the integrated reinforcing fiber material and synthetic fiber material plural times so that a folding line is obtained in a yarn length direction. In this case, a state where the reinforcing fiber material and the synthetic fiber material are laminated alternately is brought about, and a more uniform combined filament yarn in which the synthetic fiber material is dispersed to the center part can be obtained. A method of folding includes folding as if winding or staggered folding, and folding only needs to be performed so that the reinforcing fiber material and the synthetic fiber material are alternately laminated. Fig. 3(c) illustrates a sectional diagram of the combined filament yarn obtained by overlapping a plurality of integrated reinforcing fiber materials and synthetic fiber materials. In this case, too, the reinforcing fiber material and the synthetic fiber material are in the alternately laminated state, whereby the synthetic fiber material is dispersed to the center part, and a more uniform combined filament yarn can be obtained. Fig. 3(d) illustrates a sectional diagram of a combined filament yarn obtained by slitting the integrated reinforcing fiber material and synthetic fiber material in the yarn length direction. By forming the integrated reinforcing fiber material and synthetic fiber material into a wide sheet state, by slitting it by a thin width and by bundling each of them, a plurality of combined filament yarns having the same quality can be manufactured at the same time, whereby productivity can be drastically improved.

[0028] As described above, by dispersing the synthetic fiber material in accordance with the density of the sheet-state spread reinforcing fiber material and by overlapping and integrating them, a combined filament yarn which is combined more uniformly can be manufactured. Uniformity of a combined state of the obtained combined filament yarn can be checked by quantitatively analyzing a dispersed state of the synthetic fiber material in a section in a direction orthogonal to the yarn length direction of the combined filament yarn. For example, by dividing the section into a plurality of divided regions, by calculating a rate of a sectional area of the synthetic fiber material in each of the divided regions, and by checking a standard deviation relating to the calculated rate of each region, the dispersed state can be quantitatively analyzed. In this case, the smaller the standard deviation becomes, the more uniformly the synthetic fiber material is dispersed, which indicates that the combined filament yarn which is combined more uniformly can be obtained. Moreover, when molding is performed by hot press or the like using the combined filament yarn, in order for the synthetic fiber material to melt and penetrate between the reinforcing fiber materials to be filled in a state without a void, the standard deviation σ needs to be set to 25 or less.

[0029] Conditions under which molding is performed by hot press by using the combined filament yarn according to the present invention can be set to a heating temperature of 260 to 320°C, a pressure of 0.1 to 3.0 MPa, and processing time of 3 to 20 minutes. On the other hand, in a prior-art method in which a resin sheet is overlapped on arranged carbon fibers and hot press is performed, the pressure of 10 MPa or more and processing time of 30 minutes or more are needed. By using the combined filament yarn of the present invention, a molded product without a void can be obtained at a lower pressure and for a shorter processing time. That is, a high-quality molded product can be manufactured efficiently by a simple hot press device.

[Example]

[Example 1]

[0030] The combined filament yarn was manufactured by using the following materials:

<Used materials>

[0031] 

(Reinforcing fiber material)

Carbon fiber (by Mitsubishi Rayon Co. Ltd.; 50R15L)

Fiber diameter: 7 µm, number of fibers: 15000

(Synthetic fiber material)

Polyethylene terephthalate (PET) composite fiber (by KB Seiren, Ltd.; Bellcouple

(PET core-sheath type fusible yarn, core-sheath weight ratio: 1:1)

Fineness: 8 dtex, number of fibers: 1000

Use amounts of carbon fiber and composite fiber were set so that the Vf value became 49.0%.

<Manufacturing process>

[0032] The carbon fiber was subjected to the spreading processing to a width of 100 mm by a spreading method by an air flow described in Japanese Patent No. 3064019. Density of the obtained sheet-state carbon fiber was 150 fibers/mm. The composite fiber was subjected to warping processing to a width of 100 mm by using a known warping machine. The density of the obtained sheet-sate composite fiber was 10 fibers/mm. Subsequently, the carbon fiber and the composite fiber formed having a sheet shape were overlapped while being fed and then, subjected to the spreading processing similar to the spreading method of the carbon fiber so as to form an overlapped sheet material having a width of 100 mm. Then, the formed overlapped sheet material was passed between the heating rolls (170°C) so that the composite fiber is provisionally bonded to and integrated with the carbon fiber. The obtained provisionally bonded sheet material was folded four times along a folding line in the yarn length direction, and the combined filament yarn laminated in 16 layers was manufactured.

<Uniformity evaluation of combined filament yarn>

[0033] The manufactured combined filament yarn was cut off in a direction orthogonal to the yarn length direction and its section was photographed by a scanning electron microscope (by Hitachi-High-Technologies Corporation, S-3500N). Fig. 4 is a photographed image relating to the section of the combined filament yarn. In order to evaluate uniformity of the combined filament yarn, the photographed image of the section of the combined filament yarn was processed, and a dispersed state of the area of the composite fiber was evaluated. For the processing of the photographed image, commercial image-processing software (by Olympus Corporation, Stream Essential) was used. First, a region for analysis was defined by drawing a rectangle circumscribed by the section of the combined filament yarn, and the defined rectangular region was equally divided into three parts laterally and vertically, respectively, that is, nine divided regions were set. In Fig. 4, the divided regions are indicated by white straight lines.

[0034] An outline was drawn by following an outer shape of the combined filament yarn for each of the divided regions, and an area S1 of the combined filament yarn surrounded by the drawn outline and a border line of the divided region was calculated. Subsequently, an area S2 of the composite fiber surrounded by drawing a surrounding line surrounding only the composite fiber was calculated. In Fig. 4, the outline and the surrounding line are indicated by white curves. A combining fiber rate M was calculated by the following equation:

Then, the standard deviation σ relating to the combining fiber rate M calculated for each of the nine divided regions was calculated. The standard deviation σ for the combined filament yarn in Example 1 was 9.3.

[Example 2]

[0035] The materials similar to those in Example 1 were used, and the sheet forming process to the integrating process were performed similarly to Example 1. The obtained provisionally bonded sheet material was twisted at 100 times/m by the known twisting device so as to manufacture a combined filament yarn. A section of the manufactured combined filament yarn was photographed similarly to Example 1. Fig. 5 is a photographed image relating to the section of the combined filament yarn. For uniformity evaluation, image processing was applied to the section image similarly to Example 1, and the standard deviation was calculated. The standard deviation σ was 11.5.

[Example 3]

[0036] The materials similar to those in Example 1 were used, and the sheet forming process to the integrating process were performed similarly to Example 1. The obtained provisionally bonded sheet material was wound spirally in the width direction so as to manufacture the combined filament yarn. A section of the manufactured combined filament yarn was photographed similarly to Example 1. For uniformity evaluation, image processing was applied to the section image similarly to Example 1, and the standard deviation was calculated. The standard deviation σ was 15.2.

[Example 4]

[0037] The materials similar to those in Example 1 were used, and processes from the sheet forming process to the integrating process were performed similarly to Example 1. The obtained provisionally bonded sheet material was slit in the yarn length direction by a known slitter to a width of 2 mm so as to manufacture the combined filament yarn. A section of the manufactured combined filament yarn was photographed similarly to Example 1. For uniformity evaluation, image processing was applied to the section image similarly to Example 1, and the standard deviation was calculated. The standard deviation σ was 19.2.

[Comparative Example 1]

<Used material>

(Reinforcing fiber material)

[0038] The carbon fiber similar to Example 1 was used.

(Synthetic fiber material)

[0039] Polyester fiber (by KB Seiren, Ltd.; Bellcouple) 280T/16f: 30

[0040] Use amounts of carbon fiber and polyester fiber were set so that the Vf value becomes 47.5%.

<Manufacturing process>

[0041] The polyester fibers were divided into two fiber bundles, each having 15 fibers, and double covering processing was applied with the two fiber bundles by a covering device around the carbon fiber so as to manufacture the combined filament yarn. The number of windings of the fiber bundle was set to 200 times/m.

[0042] For uniformity evaluation of the manufactured combined filament yarn, a section image was photographed and image processing was applied similarly to Example 1, and the standard deviation was calculated. The standard deviation σ was 30.6.

[Example 5]

[0043] Subsequently, permeability of the composite fiber by hot press was evaluated by using the combined filament yarn obtained in Example 1. The combined filament yarn was set on a hot press device (by Imoto Machinery Co., Ltd.; IMC-180C model), setting was made at the heating temperature of 300°C and a pressurizing force of 0.14 MPa, and hot-press processing was performed for 5 minutes. The combined filament yarn was molded into a plate-shaped body having a width of approximately 4.5 mm and a thickness of approximately 0.4 mm. The molded plate-shaped body was cut off in a thickness direction, and the section was observed by an electron microscope and then, a resin was filled between the carbon fibers revealed to the section, and no void was observed.

[Example 6]

[0044] The combined filament yarn obtained in Example 2 was subjected to hot-press processing similarly to Example 5 and molded into a plate shaped body. The molded plate-shaped body was cut off in a thickness direction, and the section was observed by an electron microscope and then, a resin was filled between the carbon fibers revealed to the section, and no void was observed.

[Comparative Example 2]

[0045] The combined filament yarn obtained in Comparative Example 1 was subjected to hot-press processing similarly to Example 5 and molded into a plate shaped body. The molded plate-shaped body was cut off in a thickness direction, and the section was observed by an electron microscope and then, a void into which the resin did not penetrate between the carbon fibers revealed to the section was observed.

[Example 7]

[0046] The hot-press processing was performed similarly to Example 5 and a plate-shaped body was molded except that the heating processing temperature was set to 280°C and the pressurizing force to 1.29 MPa. The molded plate-shaped body was cut off in a thickness direction, and the section was observed by an electron microscope and then, a resin was filled between the carbon fibers revealed to the section, and no void was observed.

[Comparative Example 3]

[0047] Carbon fibers (by Mitsubishi Rayon Co. Ltd.; 50R15L) were arranged, and a polyethylene terephthalate film (by Fujimori Kogyo Co., Ltd.; 75-NT2-AS) was overlapped thereon, and the hot-press processing was applied under the condition similar to Example 7 so as to mold a plate-shaped body. The molded plate-shaped body was cut off in a thickness direction, and the section was observed by an electron microscope and then, a void into which the resin did not penetrate between the carbon fibers revealed to the section was observed.

[0048] By referring to the aforementioned Examples and Comparative Examples, it is known that a formed product without a void can be obtained by setting the standard deviation indicating the dispersed state of the synthetic fiber material of the combined filament yarn to 25 or less.

Reference Signs List

[0049] 

H

heating roll

K

spreading mechanism

R

pressure-contact roll

S

synthetic fiber material

T

reinforcing fiber material

Claims

1. A combined filament yarn in which, with a reinforcing fiber material arranged in a predetermined direction, a synthetic fiber material arranged in the same direction as that of the reinforcing fiber material is combined, wherein the synthetic fiber material is bonded to and integrated with the reinforcing fiber material, and the synthetic fiber material is dispersed so that a standard deviation relating to a rate of a sectional area of the synthetic fiber material in a divided region obtained by dividing a section of the combined filament yarn becomes 25 or less.

2. A molded product molded by using a combined filament yarn according to claim 1.

3. A manufacturing method of a combined filament yarn, comprising an overlapping process of overlapping a synthetic fiber material on a sheet-state reinforcing fiber material spread and arranged in a predetermined direction in a state where the synthetic fiber material is arranged in the same direction as that of the reinforcing fiber material and dispersed in accordance with density of the reinforcing fiber material, and an integrating process of bonding and integrating the overlapped reinforcing fiber material and synthetic fiber material.

4. The manufacturing method of a combined filament yarn according to claim 3, wherein the overlapped reinforcing fiber material and synthetic fiber material are subjected to spreading processing in the overlapping process.

5. The manufacturing method of a combined filament yarn according to claim 3 or 4, further comprising a yarn forming process of forming the bonded and integrated reinforcing fiber material and synthetic fiber material into a yarn in another form.

Drawing