JP5920764B2 - Manufacturing method of fiber reinforced composite molding material - Google Patents

Description

The present invention relates to a method for producing a fiber reinforced composite molding material in the field of fiber reinforcement, in particular, a synthetic fiber yarn that is wound around a carbon fiber.

  Many of products generally called plastic products are products that use thermoplastic resin as a raw material, and are manufactured by molding thermoplastic resin pellets with a molding apparatus.

  As one of improvement in properties such as strength and elastic modulus of such a thermoplastic resin product, a thermoplastic resin pellet mixed with high-strength and high-modulus fiber such as carbon fiber is used.

  Conventionally, this pellet has been produced by a method of kneading and extruding a fiber called a chopped strand, which is generally cut to a length of about 3 mm, and a thermoplastic resin. However, in the case of injection molding, the length of the reinforcing fiber in the molded product is substantially 1 mm or less, and the physical property improving effect is small.

  Accordingly, long fiber pellets have been developed in which the periphery of a continuous reinforcing fiber bundle is coated with a thermoplastic resin. However, the resin and the fiber are separated in the cutting process due to the low impregnation property of the resin to the reinforcing fiber bundle. In addition, there are many problems such as an increase in the size of an apparatus such as a fiber-spreading process for improving the impregnation property, and instability of the ratio of fiber to resin.

The present invention has been made in view of the above points, and in order to solve the above-described problems, the upper and lower threads of the hooking yarn of the thermoplastic synthetic fiber yarn by supplying the carbon fiber bundle to the mellow sewing machine of the lock sewing machine. A method for producing a fiber-reinforced composite knitted material using a composite fiber thread formed by winding a thread into a winding stitch, the thermoplastic synthetic fiber being formed by aligning a thermoplastic synthetic fiber thread with the carbon fiber bundle. A composite fiber yarn is formed by winding and staking the yarn thread, and the wound composite fiber yarn is inserted into a heating furnace of a tapered tubular furnace formed so that the inner diameter becomes closer to the outlet and heated. integrally joined to the carbon fiber bundle by melting the synthetic fiber yarns of thermoplasticity, method for producing a fiber-reinforced composite molding material, characterized in that cutting the composite fiber yarn and the integrally bonded to a predetermined length To provide.

In addition, one or more bundles of carbon fiber bundles bundled with multifilaments and thermoplastic synthetic fiber yarns including nylon, polypropylene, and polyester are drawn together, and a synthetic yarn of thermoplastic synthetic yarn is wound and wound. engagement to to provide a method for producing a fiber-reinforced composite molding material, characterized in that the composite fiber yarn.

Furthermore, the present invention provides a method for producing a fiber-reinforced composite molding material , characterized in that the heating furnace of the tubular furnace has a tapered shape whose inner diameter on the outlet side is 50 to 80% of the inner diameter on the inlet side.

Furthermore, another object of the present invention is to provide a method for producing a fiber-reinforced composite molding material , characterized in that a composite fiber yarn that is integrally melt-heated and joined is cut into pellets having a length of several mm to several tens of mm.

Furthermore, another object of the present invention is to provide a method for producing a fiber reinforced composite molding material , characterized in that a composite fiber yarn that is integrally melted by heating and melting is cut into a length of several tens of centimeters to several meters.

Furthermore, the heating furnace to heat the carbon fiber bundle of the composite fiber yarn as the microwave heating, the carbon fiber bundle with molten thermoplastic synthetic fiber yarn to the composite fiber yarn and integrally bonded It is in providing the manufacturing method of the fiber reinforced composite molding material characterized.

According to the present invention, a composite formed by supplying a carbon fiber bundle to a mellow sewing machine of a lock sewing machine and winding an upper thread and a lower thread of a thermoplastic synthetic fiber thread by wrap-around stitching. A method for producing a fiber reinforced composite knitted material using fiber yarns, wherein the synthetic fiber yarns of thermoplastics are aligned with the carbon fiber bundles and the synthetic yarns of the thermoplastic synthetic fiber yarns are wound and sewed together. The composite fiber yarn thus wound and sewn is inserted into a heating furnace of a tapered tubular furnace formed so that the inner diameter becomes closer to the outlet, and heated to melt the thermoplastic synthetic fiber yarn to melt the carbon fiber bundle. The carbon fiber bundle is supplied to the lock sewing machine mellow sewing machine to cut the composite fiber yarn integrally bonded to the predetermined length, so that Winding and hooking of thread and bobbin thread The composite fiber yarn can be used to make a fiber reinforced composite knitted material, and a fiber thermoplastic resin is wound around the reinforcing fiber to produce the composite fiber yarn, so the ratio of the reinforcing fiber to the resin can be adjusted accurately. Thus, the resin impregnation property can be improved, and the ratio of the reinforcing fiber to the resin can be stably adjusted with a simple apparatus, and a strong fiber-reinforced composite molding material can be obtained.
Then, a high temperature resin impregnating property can be realized by melting the thermoplastic resin yarns aligned with the reinforcing fiber bundle and the hooking yarn, and the heating furnace of the tapered tubular furnace formed so that the inner diameter becomes closer to the outlet. By passing the wire, a force is applied to the composite fiber yarn from the surroundings, so that the molten resin can enter inside, and when the composite fiber yarn is heated in a heating furnace, the thermoplastic resin yarn contracts at the initial stage. Widen the carbon fiber bundle, increase the surface area, improve the resin impregnation, increase the thickness of the carbon fiber and open the fiber, and improve the dispersibility of the fiber in the resin during injection molding Tangle between each other can be prevented.

Further, as described in claim 2, one or more carbon fiber bundles in which multifilaments are bundled and thermoplastic synthetic fiber yarns containing nylon, polypropylene, or polyester are arranged together to produce thermoplastic synthetic fibers. by the winding sewing engagement with a composite fiber yarn hooking yarn yarn, made freely adjusting the ratio of the reinforcing fibers and the resin can be improved impregnation of the resin, to obtain a fiber-reinforced composite molding material having strength it can.

  Further, as described in claim 3, the heating furnace of the tubular furnace has a tapered shape in which the inner diameter of the outlet side is 50 to 80% of the inner diameter of the inlet side. Impregnation into the yarn can be improved and a good fiber-reinforced composite molding material can be obtained.

Furthermore, as according to claim 4, by cutting into pellets of a length of several mm~ dozen mm composite fiber yarn has been integrally joined by heating and melting, the fiber-reinforced composite molding material as described above It can be pelletized for injection molding or press molding.

Furthermore, as claimed in claim 5, by cutting the length of several tens cm~ number m the composite fiber yarn has been integrally joined by heating and melting, pressing the long products and large products that require strength Can be molded.

Furthermore, as in claim 6, the heating furnace is of microwave heating, the carbon fiber bundle of the composite fiber yarn is heated, the thermoplastic synthetic fiber yarn is melted and integrally joined to the carbon fiber bundle. by the composite fiber yarn can be heat generation carbon fiber bundles of the composite fiber yarn in a microwave heating can be impregnated integrally with the composite fiber yarn you can quickly melt the resin.

Figure for explaining the formation of a composite fiber yarn of one embodiment of the present invention, Expansion explanatory drawing (a) of the composite fiber yarn same as above, enlarged explanatory drawing (b) in which the aligned yarn is aligned with the reinforcing fiber, Enlarged photo of other composite fiber yarns Perspective view of the heating furnace, Cross-sectional view of the above, A perspective explanatory view of another embodiment of the heating furnace, Photo of the cut pellets, A photograph of the cut long molding material, The enlarged photograph (a) before heating and the enlarged photograph (b) immediately after heating of the composite fiber yarn same as above, An enlarged cross-sectional photo of the same pellet, The expanded cross-sectional photograph of the pellet of another Example same as the above.

The method for producing a fiber-reinforced composite molding material of the present invention is formed by supplying a carbon fiber bundle to a mellow sewing machine of a lock sewing machine and hooking the upper thread and the lower thread of a thermoplastic synthetic fiber thread and winding them together by winding. A method for producing a fiber reinforced composite knitted material using a composite fiber yarn, wherein the synthetic fiber yarn of thermoplastic is aligned with the carbon fiber bundle, and the composite yarn of thermoplastic synthetic yarn is wound and sewed together. A fiber yarn is formed, and this wound composite fiber yarn is inserted into a heating furnace of a tapered tubular furnace having an inner diameter made smaller as it approaches the outlet, and heated to melt the thermoplastic synthetic fiber yarn to carbon integrally joined to the fiber bundle, it is characterized by cutting the composite fiber yarn and the integrally bonded to a predetermined length.

  The composite fiber yarn 1 is supplied to the mellow sewing machine 2 by changing one or more bundles of carbon fiber bundles 3 in which multifilaments are bundled by using the mellow sewing machine 2 of overlock or lock sewing machine as shown in FIG. Then, as shown in FIG. 2A, the synthetic fiber yarn hooking yarn 4 is formed by winding the carbon fiber bundle 3 by changing the tension as necessary.

  The carbon fiber bundle 3 in which multifilaments are bundled can use PAN-based carbon fibers of polyacrylonitrile or pitch-based carbon fibers of petroleum pitch, and the PAN system has excellent characteristics as a composite material using a resin as a matrix. Especially suitable for lightweight structure. The filaments of the carbon fiber bundle 3 are extremely thin with a diameter of about 7 to 10 μm, and these filaments are bundled in a range of 1000 to 12000 as described above. The thickness is about several mm to 1 mm, and a sizing process is performed to coat a small amount of resin in order to prevent the occurrence of fluff.

  The carbon fiber bundle 3 can be wound around the hook yarn 4 in a predetermined amount such as one bundle, but the hook yarn 5 is wound around the plurality of bundles such as 3 to 7 bundles, preferably 3 to 5 bundles. However, the composite fiber bundle yarn 1 can be made thick or bulky. The carbon fiber bundle 3 can be arranged in a single bundle or a three-core shape, and in an axially symmetrical double or triple shape on these outer peripheral portions.

  As shown in FIG. 2 (b), the carbon fiber bundle 3 is aligned with random alignment yarns 5 of thermoplastic synthetic fiber yarns including nylon, polypropylene or polyester having a predetermined diameter of 100 to 1200 denier. An appropriate number of about 3 to 10 can be inserted in the shape. Nylon and polyester are preferable as the assembling yarn 5 of the thermoplastic synthetic fiber yarn to be drawn and inserted. By aligning the alignment yarn 5 of the thermoplastic synthetic fiber yarn, the ratio of the reinforcing fiber and the resin can be easily adjusted freely, the impregnation property of the resin can be improved, and a strong fiber-reinforced composite molding material can be obtained. Can be.

  As the hooking yarn 4, a thermoplastic synthetic fiber yarn containing nylon, polyester, polypropylene, or polyethylene can be used, and an extra fine material of 0.1 to 10 denier can be hooked without being bulky so that it becomes a honey fabric. Although it can be formed, if the carbon fiber bundle 3 is thick or bulky, a thread having an appropriate thickness of 100 to 350 denier can be used if necessary. Further, it is preferable that the hook yarn 4 is supplied to the mellow sewing machine 2 and engaged with the carbon fiber bundle 3 and the draw yarn 5 at a pitch of 1 to 5 mm, and the carbon fiber bundle 3 is scattered or fuzzy. It is preferable because it can effectively prevent peeling. A fiber-reinforced composite molding material having a predetermined resin content that makes it possible to easily adjust the resin content by changing the winding pitch of the hooking yarn 4 of the thermoplastic synthetic fiber yarn, taking advantage of the structural characteristics of the yarn. Can be obtained.

  The composite fiber yarn 1 is produced by the sewing mechanism of the mellow sewing machine 2 as described above, and each yarn is compounded into one composite fiber yarn at the sewing site, but the carbon fiber bundle 3, the aligned yarn 5, the hooking By appropriately adjusting the tension of the yarn 4, the carbon fiber bundle 3 and the draw yarn 5 can be undulated and the composite fiber yarn 1 can be produced. Within the scope of the present invention, the carbon fiber bundle 3, the hook yarn 4, and the draw yarn 5 can have an appropriate thickness and an appropriate number depending on the object.

Sewing needles in this manner engages with engaging thread 5 Pull aligned yarns 5 pulled aligned with the thermoplastic synthetic fiber yarn, such as a bundle or a plurality bundles and nylon or polyester carbon fiber bundle 3, to swing the lifting of the main Romishin 2 Combined with the needle thread of thermoplastic synthetic fiber thread such as nylon or polyester, the upper and lower threads of thermoplastic synthetic fiber thread such as nylon or polyester, which is the same as the hook thread 4, are wound and wound. The fiber bundle yarn 1 can be obtained.

  The composite fiber yarn 1 produced in this way is inserted into a heating furnace 6 and heat-treated as shown in FIG. 4, and the carbon fiber bundle 3 is impregnated with the assembling yarn 5 and the hook yarn 4 of the synthetic fiber yarn and integrated. To do. Insertion of the composite fiber yarn 1 into the heating furnace 6 can be performed by inserting the composite fiber yarn 1 directly into the heating furnace 6 from the mellow sewing machine 2 or once winding the yarn around a yarn tube and inserting the yarn into the heating furnace 6. The latter is preferable because good workability and heating conditions can be easily set.

  The set temperature of the heating furnace 6 is 30 to 50 degrees or more higher than the melting point of the thermoplastic resin yarn, and by this means, the draw yarn 5 and the hook yarn 4 which are thermoplastic resin yarns are continuously melted to form a composite fiber. Yarn 1 can be produced. In order to improve the heating effect, the heating section of the tubular furnace of the heating furnace 6 is provided with a resin tube 7 in close contact with the inside of the metal pipe as shown in FIG. 5, and the composite fiber yarn 1 is allowed to pass therethrough. Is preferred. As the resin tube 7, heat-resistant and low-friction tubes such as Teflon (registered trademark) and silicone can be used. By using these tubes, molten resin does not adhere to the inside of the tube. , Stable and continuous heating.

  In order to increase the melting and impregnation of the resin, it is preferable that the heating furnace 6 has a smaller inner diameter d closer to the outlet, and a plurality of tubular furnaces having an inner diameter d of d3> d2> d1 are joined and used as shown in FIG. You can also. By making the inner diameter d closer to the outlet, the molten thermoplastic resin is easily impregnated into the material. The inner diameter d of the first tubular furnace is preferably about the same as the apparent diameter of the composite fiber yarn 1, and the inner diameter d of the outlet tubular furnace is preferably about 50 to 80% of the initial inner diameter d. In the case of the heating furnace 6 of FIG. 6, the first Teflon (registered trademark) tube of the resin tube 7 having an inner diameter of 1.5 to 3 mm was used. As described above, the impregnation property of the resin can be improved by using the tapered tube whose inner diameter is smaller on the outlet side than the inlet.

  If the heating furnace 6 is of a microwave heating type, the carbon fiber bundle 3 of the composite fiber yarn 1 can be heated by microwaves, the carbon fiber bundle 3 in the composite fiber yarn 1 can be heated, and the resin can be quickly supplied. The composite fiber yarn 1 can be melted and impregnated integrally.

  The composite fiber yarn 1 inserted into the heating furnace 6 and heated and melted in this way is hardened with a resin melted by natural cooling, dry air, cold air, or the like, and the composite fiber yarn 1 in which the thermoplastic resin is hardened is obtained with a strand cutter or the like. Can be cut to a length of mm to several meters. When cut with a length of about several mm to several tens of mm, a pellet can be produced as shown in FIG. When cutting with a length of about several tens of millimeters to several meters, a long molding material can be produced as shown in FIG.

  Conventionally, an apparatus for melting and applying a thermoplastic resin has been required. Further, since the carbon fiber is opened before the impregnation in order to improve the impregnation property of the resin, the apparatus cost is also expensive. However, in the present invention, as described above, it can be manufactured with a simple and small device, can be manufactured from a small amount, can be manufactured at a low cost, and can be used for multi-product small lot production for prototype development and the like. Can be easily handled.

  In addition, conventionally, since the reinforcing fiber is impregnated in a molten state, it is difficult to control the amount of adhesion. However, in the present invention, since it is produced from a composite fiber yarn of reinforcing fiber and fibrous thermoplastic resin, the reinforcing fiber yarn and the resin fiber yarn are aligned or engaged as described above, so that the reinforcing fiber and the resin are The ratio can be adjusted easily and accurately. Therefore, the material can be easily changed as long as the ratio can be easily changed and the resin can be fiberized.

  Furthermore, if the resin impregnating property is low, for example, when the resin part and the fiber are separated in the cutting process, the resin and the fiber are separated during transportation, or when there are many fibers on the surface, the fiber is injected during injection molding. The fibers are entangled and the fibers are not evenly dispersed. Further, the fiber is often damaged, and the fiber is broken to shorten the fiber length. As a result, the strength is insufficient.

  However, in the present invention, high impregnation of the resin can be realized by melting the draw yarn 5 and the hook yarn 4 of the thermoplastic resin yarn aligned with the reinforcing fiber bundle 3. Then, by changing the inner diameter of the tubular heating furnace 6 as described above, a force that is pressed against the composite fiber yarn 1 from the surroundings acts, and the molten resin can enter inside. Moreover, when the composite fiber yarn 1 is heated in the heating furnace 6, the thermoplastic resin yarn contracts in the initial stage to widen the carbon fiber bundle 3 and increase the surface area. As a result, the resin impregnation property is improved. The states before and immediately after heating (300 ° C.) of the composite fiber yarn 1 are shown in FIGS. The apparent thickness of the carbon fiber increases and opens.

  A 840D multifilament nylon 6 alignment yarn 5 is aligned with a 12K (φ7 μm) carbon fiber bundle 3 and supplied to the mellow sewing machine 2, and three 315D monofilament nylon 6 engagement yarns 4 are combined to form a composite. A fiber yarn 1 was produced. The produced composite fiber yarn 1 is wound around a yarn tube, and is passed through heating portions of two tubular heating furnaces 6 having an inner diameter of 3 mm and 2 mm of a Teflon (registered trademark) resin tube 7 installed inside the yarn. 5 and hook yarn 4 were melt impregnated. The inner diameter of the Teflon (registered trademark) resin tube 11 on the outlet side is 2 mm and 1.5 mm. Note that the temperature of both heating furnaces 6 was set to 260 ° C.

  The heated and melted composite fiber yarn 1 drawn from the heating furnace 6 was naturally cooled and then cut at a pitch of about 10 mm as shown in FIG. The passing speed of the composite fiber yarn is about 2 mm / min. 10A and 10B show cross sections of pellets obtained by cutting the bundle-like heat-melted composite fiber yarn 1 after natural cooling. As shown in FIGS. 10 (a) and 10 (b), the carbon fiber bundle 3 is deformed into a U-shape, and the resin is present inside thereof. The outside of the pellet is completely covered with resin, and the carbon fiber bundle 3 does not appear on the outside. In addition, the state before and immediately after heating (300 ° C.) of the composite fiber yarn 1 is increased in the apparent thickness of the carbon fiber as shown in FIGS. 9 (a) and 9 (b). I can confirm that.

  This is because the carbon fiber bundle 3 has been opened along with the thermal contraction of the hook yarn 4 and the draw yarn 5 in the initial stage of heating. The spread of the carbon fiber bundle 3 can be expected to improve the dispersibility of the fibers in the resin during injection molding and prevent the fibers from being entangled. Also, by changing the inner diameter of the Teflon (registered trademark) resin tube 7 in the heating furnace 6, both can directly apply heat to the composite fiber yarn 1, impregnation of the molten resin into the yarn, carbon fiber There were effects such as prevention of exposure of the bundle 3 to the pellet surface.

  Next, three 300D monofilament polyester yarns (PET copolymerized) assembling yarns 5 are arranged on a 3K (φ7 μm) carbon fiber bundle 3 and supplied to the mellow sewing machine 2 to supply three 300D monofilament polyesters. Yarn (PET copolymerization) hook yarn 4 was hooked at a pitch of 5 times / inch to produce composite fiber yarn 1. Further, the produced three composite fiber yarns 1 were inserted in place of the reinforcing fibers and the aligning yarns at the time of production with the mellow sewing machine 2 and simultaneously covered with 300D polyester yarn to produce the composite fiber yarn 1.

  The produced composite fiber yarn 1 is wound around a yarn tube in the same manner as described above, and is passed through the heating parts of two tubular heating furnaces 6 having an inner diameter of 3 mm and 2 mm of a Teflon resin tube 7 installed inside. 5 and hook yarn 4 were melt impregnated. Note that the temperature of both heating furnaces 6 was set to 300 ° C.

  The heated and melted composite fiber yarn 1 drawn from the heating furnace 6 was naturally cooled and then cut at a pitch of about 10 mm. The passing speed of the composite fiber yarn is about 2 mm / min. 11A and 11B show cross sections of the prepared pellets. Since it is produced from three composite fiber yarns 1, carbon fiber bundles can be confirmed at three locations by the three carbon fiber bundles 3. Although it is in the form of a bundle, the fibers are dispersed at regular intervals, and an improvement in the dispersibility of the fibers during injection molding can be expected. Resin is present inside the pellet, and its surface is almost covered with resin. Therefore, it is possible to prevent troubles such as separation of fibers and resin in the cutting process of pellet production and entanglement of fibers during injection molding.

  In the above description, the pellet has been described, but the same applies to the molding material to be cut into a long shape.

  The present invention can be used in place of conventional metal and resin moldings, and is similar to mechanical parts, FRP and CFRP, such as automobile bodies, bumpers and their parts, boat bodies and yacht ship bodies and their parts. Parts, train bodies and their parts, sports tennis rackets, golf club shafts, heads, skis, snow boats, helmets for daily necessities, safety shoes, attache cases, cases and parts such as personal computers and mobile phones in the OA field It can be widely used in civil engineering, architectural reinforcements, TVs, medical equipment, laser devices, military helmets and bulletproof vests, and other applications that require light weight and high strength.

DESCRIPTION OF SYMBOLS 1 ... Composite fiber yarn 2 ... Mellow sewing machine 3 ... Carbon fiber bundle 4 ... Hanging yarn 5 ... Assortment yarn 6 ... Heating furnace

JP 2001-1229827 A JP 2009-263482 A JP 2010-121250 A

Claims (6)

A fiber-reinforced composite knitted material that uses a composite fiber yarn that is formed by supplying a carbon fiber bundle to a mellow sewing machine of a rock sewing machine and winding the upper and lower threads of a synthetic synthetic yarn with an overhang . A manufacturing method comprising :
The above-mentioned carbon fiber bundle is lined with thermoplastic synthetic fiber yarns, and the synthetic fiber yarns of thermoplastic synthetic fiber yarns are wound together and formed into a composite fiber yarn. The wound composite fiber yarn has an inner diameter close to the outlet. It is inserted into a heating furnace of a tapered tubular furnace formed so small that it is heated to melt the thermoplastic synthetic fiber yarn and integrally bonded to the carbon fiber bundle, and this integrally bonded composite fiber yarn is method for producing a fiber-reinforced composite molding material, characterized in that cutting to length. Composite fiber yarn by winding one or more bundles of carbon fiber bundles bundled with multifilaments and thermoplastic synthetic fiber yarns containing nylon, polypropylene, and polyester, and winding the synthetic yarns of thermoplastic synthetic yarns method for producing a fiber reinforced molding material of claim 1,. The method for producing a fiber-reinforced composite material according to claim 1, wherein the heating furnace of the tubular furnace has a tapered shape in which the inner diameter on the outlet side is 50 to 80% of the inner diameter on the inlet side. The method for producing a fiber-reinforced composite molding material according to any one of claims 1 to 3, wherein the composite fiber yarn integrally bonded by heating and melting is cut into pellets having a length of several mm to several tens of mm. The method for producing a fiber-reinforced composite molding material according to any one of claims 1 to 3, wherein the composite fiber yarn integrally bonded by heating and melting is cut into a length of several tens of centimeters to several meters. The furnace was heated carbon fiber bundles of the composite fiber yarn as the microwave heating, to melt the thermoplastic synthetic fiber yarns of claims 1 to composite fiber yarn and integrally joined to the carbon fiber bundle 5 The manufacturing method of the fiber reinforced composite molding material in any one of.