Fiber-reinforced resin draw-molded body and method for producing the same

Abstract

The present invention is a fiber-reinforced resin draw-molded body obtained by molding a fiber sheet, wherein the fiber sheet is a semi-preg sheet obtained by at least melting and adhering a thermoplastic powder resin serving as a matrix of the draw-molded body to a fiber surface, the fiber-reinforced resin draw-molded body is obtained by drawing and molding the fiber sheet, and filling and integrating the thermoplastic resin within and between the fiber sheets. The molded body (40) is molded by the following method: converging the fiber sheet (33) and supplying it to a heating section (34) of a draw-molding die (37); heating the heating section (34) to a temperature of the melting point or the resin flow temperature of the thermoplastic resin or higher while compressing the fiber sheet (33); performing molding in a molding section (35); performing cooling in a cooling section (36) to produce a draw-molded body; and drawing the draw-molded body from the draw-molding die (37) using draw rollers (38a, 38b).

Description

Technical Field

[0001] This invention relates to fiber-reinforced resin pultruded articles using semi-preg sheets and methods for manufacturing the same. Background Technology

[0002] Fiber-reinforced resin materials are used in various fields and applications, but the demand for fiber-reinforced resin composites with higher strength or impact resistance is constantly increasing. In particular, fiber-reinforced resins are being developed in combination with various matrix resins.

[0003] Wires made from thermosetting resins are easy to process, but their slow molding speed, brittleness, and difficulty in secondary processing are considered problems. On the other hand, due to the fast molding speed, toughness, and ease of secondary processing of thermoplastic resins, fiber-reinforced resins using thermoplastic resins have attracted attention for making wires.

[0004] However, thermoplastic resins have high viscosity, making it difficult for them to impregnate fiber bundles. Therefore, several techniques for forming filaments and impregnating resins have been proposed. Patent Document 1 proposes using a distributor to separate prepreg sheets impregnated with thermoplastic resin from sheet-like reinforcing fibers and forming them into rods. Patent Document 2 proposes winding sheet-like carbon fiber prepreg from the ends and using a filament winding machine to wind the carbon fibers around the outer periphery of the carbon fiber bundle. Patent Document 3 proposes using a binding material to bind the fiber bundle and impregnating it in a thermoplastic resin solution to form filaments. Patent Document 4 proposes folding the ends of a unidirectional fabric inward to form a rod shape.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 5-50434

[0008] Patent Document 2: Japanese Patent Application Publication No. 7-23679

[0009] Patent Document 3: Japanese Patent Application Publication No. 2016-172870

[0010] Patent Document 4: Japanese Patent Application Publication No. 2007-1299 Summary of the Invention

[0011] The problem the invention aims to solve

[0012] However, the existing technology described above, which involves directly impregnating roving with a thermoplastic resin that can form a liquid, suffers from limitations on the type of resin that can be used to form a liquid. Furthermore, methods using prepreg sheets require steps such as heating the sheet to soften it or cutting it into narrow strips and stacking them in multiple layers, due to the inherent rigidity of the prepreg sheet. Additionally, the high cost of prepreg sheets and the need for cutting further complicate matters, thus raising concerns about cost and manufacturing speed (productivity).

[0013] To address the problems of the prior art, the present invention utilizes semi-impregnated sheets with good operability and flexibility to provide a fiber-reinforced resin pultruded body with excellent moldability and capable of continuous molding, and a method for manufacturing the same.

[0014] means for solving problems

[0015] The fiber-reinforced resin pultruded body of the present invention is characterized in that it is a fiber-reinforced resin pultruded body obtained by molding a fiber sheet, wherein the fiber sheet is a semi-impregnated sheet obtained by melting and bonding a thermoplastic powder resin as a matrix to at least the fiber surface, and the fiber-reinforced resin pultruded body is formed by drawing the fiber sheet and filling the fiber sheet with the thermoplastic resin and integrating it.

[0016] The method for manufacturing a fiber-reinforced resin pultruded article of the present invention is characterized in that it is a method for manufacturing a fiber-reinforced resin pultruded article using fiber sheets, wherein the fiber sheets are semi-impregnated sheets obtained by fusion bonding at least on the fiber surface a thermoplastic powder resin that forms a matrix.

[0017] The fiber sheet is bundled and fed to the heating section of the drawing die.

[0018] The heating element heats the thermoplastic resin to above its melting point or flow temperature while simultaneously compressing the fiber sheet.

[0019] The forming process is carried out in the forming section of the drawing die.

[0020] The material is cooled in the cooling section of the drawing die to form a drawn body.

[0021] The drawn body is drawn.

[0022] The effects of the invention

[0023] The fiber-reinforced resin pultruded body of the present invention is formed by bundling and drawing the aforementioned fiber sheets, and by filling the fiber sheets and spaces between the fiber sheets with the aforementioned thermoplastic resin and integrating them. Furthermore, by using a semi-impregnated sheet with good workability and flexibility, a fiber-reinforced resin pultruded body and its manufacturing method are provided, exhibiting excellent moldability and enabling continuous molding of pultruded bodies. That is, the fiber-reinforced resin pultruded body of the present invention, by using a highly flexible unimpregnated and / or semi-impregnated semi-impregnated sheet, exhibits good pultruability and enables continuous molding of pultruded bodies. In addition, the manufacturing method of the present invention is a versatile molding method, allowing for the molding of bodies of various shapes. Furthermore, the pultruded body using thermoplastic resin as the matrix resin exhibits good secondary processing properties and is easily processed into curved wires or parts such as rivets. Attached Figure Description

[0024] Figure 1 A is a schematic perspective view of a fiber-reinforced resin pultruded article according to an embodiment of the present invention. Figure 1 B is its schematic cross-sectional view.

[0025] Figure 2 This is a schematic process diagram illustrating a method for manufacturing a fiber-reinforced resin pultruded article according to an embodiment of the present invention.

[0026] Figure 3 Figure A is a schematic illustration of a method for manufacturing a fiber-reinforced resin pultruded article according to an embodiment of the present invention, in which a fiber sheet is folded and supplied. Figure 3 B is a schematic diagram illustrating the winding and supply. Figure 3 C is a schematic diagram illustrating the supply of multiple layers of fiber sheets cut into long strips.

[0027] Figure 4 This is a schematic perspective view of the fiber sheet used in molding a fiber-reinforced resin pultruded body according to an embodiment of the present invention.

[0028] Figure 5 It is along Figure 4 A schematic cross-sectional view of the fiber sheet in the width direction.

[0029] Figure 6 It means Figure 4 The diagram shows a schematic process diagram of the manufacturing method of the fiber sheet.

[0030] Figure 7 This is a photograph showing the appearance of the fiber-reinforced resin pultruded article obtained in Embodiment 1 of the present invention, viewed from above.

[0031] Figure 8 yes Figure 7The image shown is a magnified cross-sectional photograph of the fiber-reinforced resin pultruded body.

[0032] Figure 9 Photograph A is an image of the appearance of the fiber-reinforced resin pultruded article obtained from above in Embodiment 2 of the present invention. Figure 9 B is a photograph showing the appearance of the fiber-reinforced resin pultruded article obtained from the front view of Embodiment 2 of the present invention.

[0033] Figure 10 yes Figure 9 The image shown is a magnified cross-sectional photograph of the fiber-reinforced resin pultruded body. Detailed Implementation

[0034] This invention relates to a fiber-reinforced resin pultruded body using fiber sheets. The fiber sheet is a semi-impregnated sheet in which a thermoplastic powder resin, forming the matrix of the pultruded body, is fused and bonded to at least the fiber surface. The fiber-reinforced resin pultruded body of this invention is formed by drawing the fiber sheet in a bundled state, and by filling the fiber sheet and spaces between the fiber sheets with the thermoplastic resin, thus integrating them into the structure. The fiber sheet can be a semi-impregnated sheet, and can be a unidirectional continuous fiber sheet, a multidirectional fiber sheet, a fabric, a braid, etc. Furthermore, the term "filling" here refers to impregnating the fiber sheet with thermoplastic resin, filling the spaces between the fiber sheets.

[0035] The interior of the aforementioned fiber-reinforced resin pultruded body is preferably in a state where the fiber sheet is amorphously folded. When the fiber sheet is bundled and pulled out from the mold for molding, the interior of the molded body becomes a state where the fiber sheet is amorphously folded, and the aforementioned thermoplastic resin fills the interior and spaces between the fiber sheets to form a solid molded body, thereby reducing porosity. When the interior of the aforementioned fiber-reinforced resin pultruded body is in a state where the fiber sheet is amorphously folded, it becomes a molded body with uniform stress and no directional orientation.

[0036] The fiber-reinforced resin pultruded body described above has pultrusion marks on its surface. Furthermore, at least a portion of the fibers constituting the fiber sheet are present on the surface. If the fiber sheet is bundled and drawn in a die for molding, pultrusion marks remain on the surface of the molded body, allowing identification of whether pultrusion has been performed.

[0037] The fiber volume ratio (Vf) of the fiber sheet used in this invention is preferably 25-70% by volume, and the thermoplastic resin ratio is preferably 30-75% by volume, more preferably 30-60% by volume of fiber (Vf) and 40-70% by volume of resin. Therefore, the resin component of the fiber sheet can be directly used as the matrix resin component of the molded article, eliminating the need to add new resin when manufacturing the molded article.

[0038] The fiber-reinforced resin pultruded body of the present invention is a continuous material or cut into a specified length. The cross-sectional diameter or thickness is preferably 0.2–15 mm, more preferably 1–10 mm. The cross-sectional shape can be any shape such as circular, square, C-shaped, H-shaped, L-shaped, etc. The pultruded body can be linear, rod-shaped, flat (plate-shaped), etc.

[0039] Preferably, the fiber sheet used in this invention comprises cross-linked fibers in a direction intersecting with unidirectional continuous fibers, and the aforementioned thermoplastic resin integrates the unidirectional continuous fibers and the cross-linked fibers. The main component of the fiber sheet is unidirectional continuous fibers that have been opened and are arranged in a unidirectional parallel configuration. The secondary component of the fiber is preferably cross-linked fibers arranged in a direction intersecting with the unidirectional continuous fibers. The thermoplastic resin is preferably applied as a powder from the unidirectional continuous fibers and the cross-linked fibers, and is thermally melt-bonded to at least the surface of the unidirectional continuous fibers, thus integrating the unidirectional continuous fibers and the cross-linked fibers. Since the unidirectional continuous fibers and the cross-linked fibers are integrated by the thermoplastic resin that has been thermally melt-bonded, the sheet has good processability and good operability during bundling, drawing, and thermoforming.

[0040] The aforementioned fiber sheet is preferably a semi-impregnated sheet in which a thermoplastic powder resin, serving as the matrix of the draw-formed body, is attached to and thermally melt-bonded to the surface of unidirectional continuous fibers. Through molding, the thermoplastic resin on the surface of this semi-impregnated sheet fills the interior and spaces between the fiber sheets. This results in a molded body with excellent formability and reduced porosity.

[0041] When the total weight of unidirectional continuous fibers and cross-linked fibers is set to 100% by mass, the unidirectional continuous fibers are preferably 75-99% by mass, more preferably 80-97% by mass, and even more preferably 85-97% by mass. Furthermore, the cross-linked fibers are preferably 1-25% by mass, more preferably 3-20% by mass, and even more preferably 3-15% by mass. Within the above ranges, a fiber sheet with high integrity and high tensile strength in the width direction is obtained. The average length of the cross-linked fibers is preferably 1 mm or more, and even more preferably 5 mm or more. The upper limit of the average length of the cross-linked fibers is preferably 1000 mm or less, more preferably 500 mm or less. If the average length of the cross-linked fibers is within the above ranges, a fiber sheet with high strength in the width direction and excellent processability is obtained.

[0042] The preferred mass of the fiber sheet per unit area is 10–500 g / m². 2 More preferably 20–400 g / m 2 The optimal value is 30–300 g / m³. 2 If it falls within the above range, the operation of bundling and drawing the fiber sheet is easy.

[0043] The fiber sheet used in this invention may include auxiliary yarns disposed in an orientation other than that of the unidirectional continuous fibers. The auxiliary yarns maintain a constant orientation of the fiber sheet. Examples of auxiliary yarns include glass fibers, aramid fibers, polyester fibers, nylon fibers, and vinylon fibers.

[0044] The fibers used in the aforementioned fiber sheets are preferably selected from at least one of carbon fiber, glass fiber, and high-modulus fibers with an elastic modulus preferably of 380 cN / dtex or higher. Examples of such high-modulus fibers include aramid fibers, particularly para-aramid fibers (elastic modulus: 380–980 cN / dtex), polyaryl ester fibers (elastic modulus: 600–741 cN / dtex), heterocyclic polymer (PBO, elastic modulus: 1060–2200 cN / dtex) fibers, high molecular weight polyethylene fibers (elastic modulus: 883–1413 cN / dtex), and polyvinyl alcohol fibers (PVA, strength: 14–18 cN / dtex). These fibers are useful as resin-reinforcing fibers. Carbon fiber, in particular, is useful.

[0045] The thickness of a single fiber sheet is preferably 0.01 to 2.0 mm, more preferably 0.02 to 1 mm, and even more preferably 0.05 to 0.5 mm. Within these ranges, the operation of bundling and drawing the fiber sheet is easier.

[0046] The aforementioned thermoplastic resins may include polyamide resins, polycarbonate resins, polypropylene resins, polyester resins, polyethylene resins, acrylic resins, phenoxy resins, polystyrene resins, polyimide resins, and polyetheretherketone resins, but are not limited to these.

[0047] Thermoplastic resin is in powder form, which is an aggregate of powder or particles. Furthermore, dry powder is preferred.

[0048] Next, a method for manufacturing the fiber-reinforced resin pultruded article of the present invention will be described. The method involves using a semi-impregnated sheet with a thermoplastic powder resin, which forms the matrix of the pultruded article, fused and bonded at least on the fiber surface, and comprising the following steps.

[0049] (1) The feeding process of gathering the above-mentioned fiber sheet and feeding it to the heating part of the drawing die.

[0050] (2) A heating and compression process in which the heating section of the drawing die is heated to above the melting point or resin flow temperature of the thermoplastic resin, and the fiber sheet is compressed using a drawing force.

[0051] (3) A forming process performed in the forming section of the drawing die described above.

[0052] (4) Cooling is performed in the cooling section of the drawing die to produce the drawn body.

[0053] (5) The drawing process of drawing the above-mentioned drawn body from the above-mentioned drawing die.

[0054] In the above-described supply process, one or more fiber sheets are used. The fiber sheets are preferably supplied to the heating section in at least one bundled state selected from folded, wound, and stacked long strip sheets. This allows the planar fiber sheets to approximate three-dimensional shapes such as rods. In particular, when long strip fiber sheets are supplied in a stacked manner, if the long strip sheets are staggered in the length direction, a continuous drawn-out shape without length limitations can be obtained. Furthermore, the fiber sheet bundling method can use a guide or the like. Additionally, when bundling the fiber sheets, the fiber orientation direction can be set to any angle. Moreover, bundling here refers to gathering or clustering the fiber sheets to make them formable. Examples include folding, winding, and stacking of long strip sheets.

[0055] When using wound sheets, further winding can be performed on top of the wound sheet. Winding can be done at any angle. Fiber sheets can also be stacked at any angle, such as 0°, 45°, 90°, etc. Typically, a 0° longitudinal (unidirectional) fiber sheet is used as the basic standard. 0° means that the long side of the unidirectional continuous fibers of the fiber sheet is in the same direction as the drawing direction of the drawn material (the long side of the formed body). The amount of semi-impregnated sheet insertion can be varied according to the target diameter of the formed object and the mass per unit length.

[0056] In the aforementioned heating and compression process, the fiber sheet is preferably heated to a temperature above the resin melting temperature, and the drawing speed is 10 mm to 20 m / min. By controlling these two conditions—temperature and drawing speed—the melting of the resin, its impregnation between the fibers, and the forming process can be controlled. The shape of the internal space of the heating section is preferably a cone or trumpet shape, with the diameter decreasing towards the direction of fiber sheet travel. That is, preferably, the inlet diameter (D1) of the heating section is larger than the target diameter, and the outlet diameter (D2) of the heating section and the diameter (D3) of the forming section are the same as the target diameter. Furthermore, the drawing forming die is also called a mold.

[0057] The outlet diameter (D2) of the heating section and the diameter (D3) of the forming section are, for example, 1 to 15 mm. The ratio of the inlet diameter (D1) of the heating section to the outlet diameter (D2) of the heating section is preferably 1.5 times or more, more preferably 2 times or more, and even more preferably 2.5 times or more. There is no upper limit to D1 / D2, but in practical use it is preferably 10 times or less, more preferably 8 times or less. Corresponding to the above ratio, the fiber sheet of the raw material is compressed by the drawing force; in other words, it is compressed while being drawn in the direction of travel. Through the above compression, a molded body with fewer pores and higher density can be obtained. The mold diameter (D4) of the cooling section is preferably the same as the outlet diameter (D2) of the mold of the heating section.

[0058] Ideally, the process from the feeding stage to the drawing stage should be a continuous process. A continuous process results in good manufacturing efficiency and reduces manufacturing costs.

[0059] If the long fiber-reinforced resin pultruded body obtained after the cooling process is of a thickness that can be wound, it can be wound continuously or cut into a specified length.

[0060] The method for manufacturing the drawn molded body of the present invention is characterized by its ability to directly form semi-impregnated sheets. The fiber sheet (semi-impregnated sheet) used in the present invention differs from prepreg sheets in that it possesses excellent shapeability due to its flexibility, allowing it to be inserted into the heating section. That is, because prepregs are rigid, folding structures are not feasible. Furthermore, from a shapeability perspective, semi-impregnated sheets such as film stacks are not preferred. In the wire manufacturing method disclosed in Patent Document 3, which uses a binding material to bind fiber bundles and impregnates them with a thermoplastic resin solution to form wires, the selection of thermoplastic resin is limited. However, in contrast, the present invention uses a fiber sheet with attached resin, so there are no limitations on the thermoplastic resin used for general molding, and almost all resins can be used. In addition, the fiber sheet used in the present invention involves thermoplastic resin powder falling onto the surface of the fiber sheet and fusing and solidifying it. Therefore, the heating and melting of the resin during molding and subsequent cooling can be carried out efficiently, resulting in a molding process with both high shapeability and high molding speed.

[0061] The following figures are used for illustration. In the following figures, the same symbols represent the same objects. Figure 1 A is a schematic perspective view of a fiber-reinforced resin pultruded body 30 according to an embodiment of the present invention. Figure 1 B is a schematic cross-sectional view. The fiber-reinforced resin pultruded body 30 is a rod-shaped body, and the cross-section shows the fiber sheet being amorphously folded. Furthermore, thermoplastic resin is filled within and between the fiber sheets and integrally integrated. Figure 1 In B, 31 is a thermoplastic resin, which is impregnated within the fiber sheet and also fills the spaces between the fiber sheets to form an integrated structure.

[0062] Figure 2 This is a schematic process diagram illustrating a method for manufacturing a fiber-reinforced resin pultruded article according to an embodiment of the present invention. The molding die 37 is a pultrusion die that sequentially comprises a heating section, a forming section, and a cooling section along the traveling direction of the fiber sheet. The fiber sheet 32 ​​is fed to the heating section 34 of the molding die 37 after being bundled by the guide 33. In the heating section 34, the fiber sheet 32 ​​is heated to a temperature above the melting point or resin flow temperature of the thermoplastic resin present on at least the surface of the fiber sheet 32. The resin flow temperature is the temperature at which the resin begins to flow. In the heating section 34, the fiber sheet is drawn and compressed in the traveling direction to form the shape of the inner cavity of the heating section 34. Next, it is introduced into the forming section 35 and shaped to the shape of the inner cavity of the forming section 35, where it is stabilized to the desired shape. Then, it is cooled in the cooling section 36 to fix the shape. The die temperature of the forming section 35 is, for example, set above the melting point or resin flow temperature of the thermoplastic resin. The cooling mechanism of the cooling section 36 is water-cooled, which is efficient. The resulting molded body is drawn from the molding die 37 using drawing rollers 38a and 38b. If the molded body is thin, it is either wound or cut into fiber-reinforced resin molded bodies 40 of a specified length using blade 39.

[0063] Figure 3 AC respectively represent an example of the form in which the fiber sheet used in the manufacturing method of the fiber-reinforced resin pultruded body according to an embodiment of the present invention is supplied to the heating section. Figure 3 A represents 41 fiber sheets in a folded state. Figure 3 B represents a wound fiber sheet 42. Figure 3 C represents the fiber sheet 43 in the state of stacked elongated fiber sheets. The fiber sheet 42 can be wound obliquely. The fiber sheets 43 in the state of stacked elongated fiber sheets can be staggered in the length direction, thereby obtaining a continuous elongated molded body.

[0064] Figure 4 This is a schematic perspective view of a carbon fiber sheet 1, an example of a fiber sheet used in a method for manufacturing a fiber-reinforced resin pultruded body according to an embodiment of the present invention. Figure 5 yes Figure 4 The diagram shows a schematic cross-sectional view of the carbon fiber sheet 1 along its width. Cross-linked fibers 3 are arranged in various directions on the surface of the split unidirectional carbon fibers 2. Additionally, resin 4 is melted and cured, adhering to the vicinity of the surface of the unidirectional carbon fibers 2 to a degree where the resin 4 is either not impregnated or partially impregnated within the unidirectional carbon fibers 2. The resin 4 bonds and fixes the cross-linked fibers 3 to the surface of the unidirectional carbon fibers 2. Figure 5As shown, cross-linked fibers 3a and 3b are present on the surface of the unidirectional carbon fiber 2. All cross-linked fibers 3a are located on the surface of the unidirectional carbon fiber 2. Cross-linked fibers 3b are partially located on the surface of the unidirectional carbon fiber 2 and partially inserted into the interior, interwoven with the carbon fiber. Resin 4 bonds and fixes the cross-linked fibers 3a and 3b to the surface of the unidirectional carbon fiber 2. Additionally, there are portions with resin 4 attached and portions 5 without resin attached. When the carbon fiber sheet 1 is heated and drawn, the portions 5 without resin attached become pathways for air to escape from the interior of the fiber sheet, and the surface resin is easily impregnated throughout the entire fiber sheet. Thus, resin 4 becomes the matrix resin of the fiber-reinforced resin molded body.

[0065] Figure 6 This is a schematic process diagram illustrating a method for manufacturing carbon fiber sheets according to one embodiment of the present invention. Carbon fiber filament bundles (tows) 8 are drawn from multiple supply spools 7 and passed between splitting rollers 21a-21j, thereby splitting them (roller splitting process 23). Air splitting can also be used instead of roller splitting. The splitting rollers can be fixed or rotated, or vibrate in the width direction.

[0066] After the fiber opening process, the opened filament bundle is clamped between clamping rollers 9a and 9b, and passed between multiple bridge rollers 12a-12b arranged therebetween. Tension is applied to the filament bundle in the range of 2.5 to 30 N per 15,000 filaments (equivalent to a group of carbon fiber filaments supplied by one supply spool), thereby producing cross-linked fibers (cross-linked fiber generation step 24). The bridge rollers can rotate or vibrate in the width direction. The bridge rollers can be, for example, multiple rollers with a wrinkled, textured, or mirrored surface, and cross-linked fibers are produced by bending, fixing, rotating, vibrating, or a combination thereof on the carbon fiber filament group. 13a-13g are guide rollers.

[0067] Subsequently, dry resin powder 15 is sprinkled from powder supply hopper 14 onto the surface of the split carbon sheet and supplied to heating device 16 under no pressure for heating, causing the dry resin powder 15 to melt. It is then cooled between guide rollers 13e-13g. Next, dry resin powder 18 is sprinkled from powder supply hopper 17 onto the back side of the split carbon sheet and supplied to heating device 19 under no pressure for heating, causing the dry resin powder 18 to melt and then cool. The sheet is then rolled onto lifting roll 20 (powder resin application process 25). The dry resin powders 15 and 18 are, for example, polypropylene resin (melting point: 150–165°C), and the temperatures in heating devices 16 and 19 are, for example, the melting point or resin flow temperature of the resin +5–60°C. The residence time is, for example, 4 seconds for each. As a result, the strength in the width direction of the split carbon fiber sheet increases, preventing the carbon fibers from unraveling, and allowing it to be used as a sheet material.

[0068] The application of powdered resin can be achieved through methods such as powder coating, electrostatic coating, blowing, and flow impregnation. The preferred method is powder coating, where the powdered resin is deposited onto the surface of the carbon fiber sheet. For example, dry powdered resin can be sprinkled onto the split carbon sheet.

[0069] The advantages of this invention can be summarized as follows.

[0070] (1) Since the fiber sheet is a semi-impregnated sheet rather than a prepreg sheet, it can be directly molded. That is, in this invention, there is no need for preheating before heating by the heating unit.

[0071] (2) Since the fiber sheet is a semi-impregnated sheet rather than a pre-impregnated sheet, it has excellent shapeability and formability.

[0072] (3) In fiber sheets, thermoplastic resin is bonded to the fibers in powder form through hot melting, resulting in good resin impregnation between fibers. That is, unlike membranes, fiber sheets exhibit excellent air permeability during molding and are less prone to pore formation. In addition, due to the use of thermoplastic resin, high-recycling molding is possible.

[0073] (4) The fibers of the fiber sheet are continuous fibers (not short fibers), such as carbon fiber. Therefore, thin and high-strength molded bodies can be obtained.

[0074] (5) Because a semi-impregnated sheet is used in this invention, the cost can be reduced compared to using the prepreg sheet described below (Example 1) or (Example 2), and the drawn body can be formed in a short time. A comparison of the time required to manufacture the drawn body is specifically as follows. The manufacturing time of the prepreg sheet is longer than that of the semi-impregnated sheet.

[0075] [Prepreg Sheets (Example 1)]

[0076] Production time of prepreg sheet + molding time (including preheating, heating, shaping time and thermosetting time)

[0077] [Prepreg Sheets (Example 2)]

[0078] The time for manufacturing the prepreg sheet + the time for shaping the prepreg sheet into a long strip + the molding time (including heating, shaping, and thermosetting time).

[0079] [Semi-impregnated sheet]

[0080] Production time of semi-impregnated sheet + forming time (including heating and shaping time)

[0081] As mentioned above, the use of semi-impregnated sheets can accelerate the manufacturing of drawn parts.

[0082] Example

[0083] The present invention will be specifically described below using examples. However, the present invention is not limited to the examples described below.

[0084] (Example 1)

[0085] (1) Unopened carbon fiber bundles

[0086] The unopened carbon fiber bundles used were manufactured by Mitsubishi Chemical, product number PYROFILETR50S15L, in the form of 15K (15,000 strands) standard tow filaments with a single fiber diameter of 7 μm. An epoxy compound was attached to the carbon fibers of these unopened bundles as a sizing agent.

[0087] (2) Fiber opening mechanism for unopened fiber bundles

[0088] use Figure 6 The fiber opening mechanism performs the fiber opening process. During the fiber opening process, the tension of the carbon fiber filament bundle (tow) is set to 15N per 15,000 filaments. This produces a fiber-opened sheet with 15K carbon fiber filaments, a fiber opening width of 500mm, and a thickness of 0.08mm. The cross-linked fiber content is 3.3% by mass.

[0089] (3) Semi-impregnated sheet

[0090] Polycarbonate (PC) resin powder (Teijin Corporation LN2520 pulverized product, melting point 240℃) was used as the dry powder resin. The average particle size of the dry powder resin was 320 μm. This is relative to 1m of carbon fiber. 2 On average, 26.7g of resin powder was applied to one side and 53.4g to both sides. The temperatures in heating devices 16 and 19 were set to 250℃, and the residence time was set to 20 seconds. The resulting fiber sheet had a mass of 133.4g / m². 2 The fiber volume (Vf) is 32% by volume, and the polycarbonate resin is 50% by volume.

[0091] (4) Drawing forming process

[0092] ·use Figure 2 The drawing apparatus shown forms the drawn body.

[0093] • The semi-impregnated sheet is stretched from the roller by 2-3m and cut into sections with a width of 350mm. Then, it is folded arbitrarily and fed to the heating section of the forming mold.

[0094] • The semi-impregnated sheet, after being heated, compressed, and shaped, is passed through the heating forming section to stabilize its shape.

[0095] • The formed semi-impregnated sheet is cooled and fixed in the cooling section 36.

[0096] • After the molded body passes through drawing rollers 38a and 38b, it is cut in 150mm lengths.

[0097] (Example 2)

[0098] As a semi-impregnated sheet, polyamide (PA6) resin powder (P101F manufactured by Ube Industries, Ltd., with a melting point of 225°C) is used. The average particle size of the dry powder resin is 320 μm. This is relative to 1m of carbon fiber. 2 On average, 24.9g of resin powder was applied to one side and 49.8g to both sides. The temperatures in heating devices 16 and 19 were set to 290℃, and the residence time was set to 20 seconds. The resulting fiber sheet had a mass of 129.8g / m². 2 The fiber volume fraction (Vf) was 47% by volume, and the PA6 resin was 50% by volume. The semi-impregnated sheet was cut to a width of 400 mm, and the drawn body was formed in the same manner as in Example 1, except as shown in Table 1. The conditions and results are summarized in Tables 1-2.

[0099] Table 1

[0100] Example 1 Example 2 Semi-impregnated resin PC PA6 Temperature of the heating section mold (°C) 290 250 Molding section mold temperature (°C) 290 250 Cooling section mold temperature (°C) (water cooling temperature) 15 15 Heating section mold diameter (mm) φ20→φ6, conical φ20→φ6, conical Heating section mold length (mm) 50 50 Molding mold diameter (m) φ6 φ6 Mold length for molding section (mm) 50 50 Cooling section mold diameter (mm) φ6 φ6 Cooling section mold length (mm) 50 50 Drawing speed (mm / min) 72 72 Size of the molded object: diameter (mm) × length (mm) φ6×150 φ6×150

[0101] (evaluate)

[0102] (1) A photograph of the appearance of the molded rod obtained in Example 1 is shown. Figure 7 Show its cross-sectional photograph Figure 8 A photograph of the appearance of the molded rod obtained in Example 2 is shown below. Figure 9 Show its cross-sectional photograph Figure 10 The cross-sectional observation of the molded articles was performed using an Olympus DSX500 microscope. The appearance of the molded articles obtained in Examples 1 and 2 was confirmed to be without problems, indicating high-quality molded articles. Regarding the cross-sectional shape, although remnants of the sheet shape were found, the porosity was low, achieving good impregnation and molding. Furthermore, the interior of the molded article exhibited an amorphous folded state of the fiber sheet. Additionally, drawing marks were present on the surface of the molded article, indicating that at least a portion of the fibers constituting the fiber sheet were present on the surface.

[0103] (2) Physical property evaluation

[0104] • Conditioning: After being placed at 23°C and 50% relative humidity for more than 48 hours, a three-point bending test is performed. The three-point bending test is conducted according to JIS K7074, and the maximum stress is measured. The apparatus used is a Shimadzu AG-50k NXD plus precision universal testing machine. In JIS K7074-1988, the bending modulus is calculated using a formula assuming a flat plate is used as the test piece. Therefore, the cross-sectional area of ​​the round bar is set to be equal to that of the flat plate, and the cross-sectional area of ​​the round bar is converted to that of the flat plate to calculate the elastic modulus.

[0105] The measurement results are shown in Table 2.

[0106] Table 2

[0107] Example 1 Example 2 Semi-impregnated resin PC PA6 Fiber Vf (volume %) 32 47 Maximum stress (MPa) 121 290 Elastic modulus (GPa) 22 35

[0108] As can be clearly seen from Table 2, the molded bodies of Examples 1-2 have good maximum stress and elastic modulus.

[0109] Based on the above, by using a semi-impregnated sheet for simultaneous impregnation and molding, linear objects such as rods and wires can also be produced. Since the semi-impregnated sheet used in this invention is essentially unimpregnated with resin but has powdered resin fused to its surface, it exhibits extremely high flexibility and does not require pre-molding heat treatment as is done with pre-impregnated sheets. Therefore, the semi-impregnated sheet used in this invention offers excellent operation and can be controlled by the heating temperature, drawing speed, and preferably the diameter of the molding die.

[0110] (Example 3)

[0111] Except for using polyphenylene sulfide (PPS) resin (melting point 278°C) as the dry powder resin for the semi-impregnated sheet and setting the carbon fiber ratio (Vf) to 45% by volume, the drawing process was carried out in the same manner as in Example 1. The resulting rod had a diameter of 6 mm and a length of 150 mm. The physical properties of this rod compared with those of iron (SS400) and aluminum (Duralumin) are shown in Table 3. Furthermore, the flexural strength and flexural modulus in Table 3 are values ​​measured or calculated according to JIS K7074, and the flexural strength has the same meaning as the maximum stress in Table 2 above.

[0112] Table 3

[0113]

[0114] As can be clearly seen from Table 3, the rod obtained in Example 3 is lighter and has higher bending strength.

[0115] Industrial availability

[0116] The fiber-reinforced resin pultruded body of the present invention can be used as rods, shafts, frames, plates, cables, etc., and its cross-sectional shape can be any shape such as circular, square, H-shaped, L-shaped, etc. Therefore, the present invention can be widely used in aviation, aerospace, automotive, sports, 3D printers, industrial applications, building components, windmills, bicycles, railways, ships, and other applications.

[0117] Explanation of symbols

[0118] 1. Carbon fiber sheet

[0119] 2 Unidirectional carbon fiber

[0120] 3, 3a, 3b cross-linked fibers

[0121] 4. Resin

[0122] 5. Parts without resin adhesion

[0123] 6. Fiber Opening Device

[0124] 7. Supply spools

[0125] 8. Carbon fiber filament bundles (unopened carbon fiber filament bundles)

[0126] 9a, 9b Clamping rollers

[0127] 12a-12b Bridge Rollers

[0128] 13a-13g guide rollers

[0129] 14, 17 Powder feeding hoppers

[0130] 15, 18 dry powder resin

[0131] Heating devices 16, 19

[0132] 20 Lifting Drum

[0133] 21a-21j Fiber Opening Roller

[0134] 23-roll fiber opening process

[0135] 24. Crosslinked fiber production process

[0136] 25. Powder Resin Implantation Process

[0137] 30, 40 fiber reinforced resin pultruded parts

[0138] 31 Integrated cross-section of thermoplastic resin impregnation

[0139] 32, 41-43 Fiber sheets

[0140] 33 Guide

[0141] 34 Heating section

[0142] 35 Molding section

[0143] 36 Cooling section

[0144] 37 Molding mold

[0145] 38a, 38b drawing rollers

[0146] 39 blades

Claims

1. A fiber-reinforced resin pulltruded body, characterized by, A fiber-reinforced resin draw-molded body obtained by molding a fiber sheet, wherein The fiber sheet is a semi-preg sheet obtained by at least fusing and adhering a thermoplastic powder resin serving as a matrix to the surface of a fiber, The fiber-reinforced resin draw-molded body is a solid molded body in which the fiber sheet is drawn-molded, the inside of which is in a state in which the fiber sheet is amorphously folded, and the inside of the fiber sheet and between the fiber sheets are filled with the thermoplastic resin and integrated.

2. The fiber-reinforced resin draw-molded body according to claim 1, wherein, The fiber sheet contains unidirectional continuous fibers in which a continuous fiber group is opened and arranged in parallel in a unidirectional manner, and a thermoplastic resin present on at least the surface of the unidirectional continuous fibers.

3. The fiber-reinforced resin draw-molded body according to claim 1, wherein, The fiber-reinforced resin draw-molded body has a fiber ratio of 25 to 70% by volume and a resin ratio of 30 to 75% by volume.

4. The fiber-reinforced resin draw-molded body according to claim 2, wherein, The fiber sheet contains crosslinked fibers in a direction that intersects the unidirectional continuous fibers, and the thermoplastic resin integrates the unidirectional continuous fibers and the crosslinked fibers.

5. The fiber-reinforced resin draw-molded body according to any one of claims 1 to 4, wherein The fibers that constitute the fiber sheet are at least one selected from the group consisting of carbon fibers, glass fibers, and high-elasticity modulus fibers having an elastic modulus of 380 cN / dtex or more.

6. The fiber-reinforced resin draw-molded body according to claim 1, wherein, The mass per unit area of the fibrous sheet is 10 to 500 g / m 2 .

7. A method for producing a fiber-reinforced resin draw-molded body, characterized by A method for manufacturing a fiber-reinforced resin draw-molded body obtained by molding the fiber sheet described in claim 1, wherein The fiber sheet is a semi-preg sheet obtained by at least fusing and adhering a thermoplastic powder resin serving as a matrix to the surface of a fiber, The method for manufacturing the fiber-reinforced resin draw-molded body includes the following steps: Constricting the fiber sheet and supplying it to a heating section of a draw-molding die, Heating the heating section to a temperature of the melting point or the resin flow temperature of the thermoplastic resin or higher while compressing the fiber sheet, Molding in a molding section of the draw-molding die, Cooling in a cooling section of the draw-molding die to produce a draw-molded body, Drawing the draw-molded body from the draw-molding die; The fiber-reinforced resin draw-molded body is a solid molded body in which the fiber sheet is drawn-molded, the inside of which is in a state in which the fiber sheet is amorphously folded, and the inside of the fiber sheet and between the fiber sheets are filled with the thermoplastic resin and integrated.

8. The manufacturing method of a fiber-reinforced resin draw-molded body according to claim 7, wherein, The fiber sheet is constricted in at least one state selected from the group consisting of a folded state, a wound state, and a state in which long fiber sheets cut into a long strip are stacked in multiple layers, and is supplied to a heating section.

9. The method of producing a fiber-reinforced resin draw-molded body according to claim 7, wherein The inlet diameter (D1) of the die of the heating section / the outlet diameter (D2) of the heating section is 1.5 times or more.

10. The method of producing a fiber-reinforced resin draw-molded body according to claim 7, wherein The drawing is a continuous process from the supply.

11. The method of producing a fiber-reinforced resin draw-molded body according to claim 7, wherein The drawn draw-molded body is wound or the drawn draw-molded body is cut to a prescribed length.

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