Manufacturing method of composite molding

Abstract

To provide a method for manufacturing a composite molding by welding a continuous fiber-reinforced thermoplastic resin sheet to a thermoplastic resin molding while heating at least one of them, and integrating them with each other.SOLUTION: A method for manufacturing a composite molding bonds both a continuous fiber-reinforced thermoplastic resin sheet A composed of continuous fibers aligned in one direction and a thermoplastic resin, and a thermoplastic resin molding B while heating at least one of them using hot air heating means 6, and integrates them with each other, wherein the hot air heating means 6 has a nozzle 8 having a polygonal cross-sectional shape with the number of ovals or apexes of 3-20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a composite molded article, and to a method for manufacturing a composite molded article in which a continuous fiber reinforced thermoplastic resin sheet and a thermoplastic resin molded article are joined and integrated while at least one of them is heated. [Background technology]

[0002] Various methods are known for manufacturing composite molded articles that integrate a fiber-reinforced thermoplastic resin (FRTP) substrate with another thermoplastic resin molded article, but there are problems with the weldability of the integrated articles.

[0003] For example, Patent Documents 1 and 2 disclose a tape application device and application method equipped with an application head that applies a tape made of a fiber bundle pre-impregnated with a thermoplastic resin to a surface while pressing the tape, and disclose an injection-molded product of a thermoplastic resin as the object to be applied. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-14120 [Patent Document 2] Japanese Patent Application Publication No. 2019-135104 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the methods described in Patent Documents 1 and 2, when a wide continuous fiber reinforced thermoplastic resin sheet is attached to a thermoplastic resin molded body, it is difficult to heat it uniformly, which can result in partial non-welding or excessive heating, which can cause voids in the composite molded body. Furthermore, when a continuous fiber reinforced thermoplastic resin sheet is attached to a three-dimensional thermoplastic resin molded body, the continuous fiber reinforced thermoplastic resin sheet needs to be shaped while being welded, so it needs to be heated uniformly at a high temperature.

[0006] Therefore, an object of the present invention is to focus on the problems in the conventional technology as described above, and to provide a method for manufacturing a composite molded body in which a continuous fiber reinforced thermoplastic resin sheet and a thermoplastic resin molded body are joined together while heating at least one of them, and are well welded and integrated. [Means for solving the problem]

[0007] In order to solve the above problems, the method for producing a composite molded body of the present invention is a method for producing a composite molded body in which a continuous fiber reinforced thermoplastic resin sheet A consisting of continuous fibers oriented in one direction and a thermoplastic resin and a thermoplastic resin molded body B are joined and integrated while at least one of them is heated using a hot air heating means, and is characterized in that the hot air heating means has a nozzle with an elliptical or polygonal cross-sectional shape with 3 to 20 vertices. [Effects of the Invention]

[0008] According to the method for producing a composite molded body of the present invention, a method for producing a well-integrated composite molded body can be provided by joining a continuous fiber reinforced thermoplastic resin sheet and a thermoplastic resin molded body. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic diagram showing an example of an attachment device for producing a composite molded body. [Figure 2] FIG. 2 is a schematic perspective view showing an example of a composite molded body. [Figure 3] FIG. 10 is a diagram showing an example of a nozzle having an elliptical cross section. [Figure 4] FIG. 10 is a diagram showing an example of a nozzle having a polygonal cross-sectional shape. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in further detail below with reference to embodiments.

[0011] The method for producing a composite molded body of the present invention is a method for producing a composite molded body in which a continuous fiber reinforced thermoplastic resin sheet A consisting of continuous fibers oriented in one direction and a thermoplastic resin and a thermoplastic resin molded body B are joined and integrated while at least one of them is heated using a hot air heating means, and is characterized in that the hot air heating means has a nozzle with an elliptical or polygonal cross-sectional shape having 3 to 20 vertices.

[0012] Figure 1 shows an example of a bonding device 1 for obtaining a composite molded product. The bonding device 1 is composed of an articulated robot 2, a head 3 attached to the tip of the articulated robot 2, a sheet conveying means 4 for supplying and conveying a continuous fiber reinforced thermoplastic resin sheet A to the head 3, and a table 5 for holding a thermoplastic resin molded product B.

[0013] A hot air heater 6 and a compression roller 7 are attached to the head 3, and a nozzle 8 is attached to the tip of the hot air heater 6. Figure 3 shows an example of a nozzle with an elliptical cross-sectional shape, and Figure 4 shows an example of a nozzle with a polygonal cross-sectional shape.

[0014] The hot air heater 6 heats gas such as nitrogen or air, and the heated gas is ejected at a predetermined temperature and flow rate from the nozzle 8 at the tip. The heated gas is blown from the nozzle 8 upstream of the attachment position, and is configured to heat at least one of the continuous fiber reinforced thermoplastic resin sheet A and the thermoplastic resin molded product B.

[0015] Next, the operation of the bonding device 1 to bond the continuous fiber reinforced thermoplastic resin sheet A will be described.

[0016] First, the sheet conveying means 4 is set at a predetermined angle, and a reel around which a continuous fiber reinforced thermoplastic resin sheet A is wound is placed on the sheet conveying device 4. The thermoplastic resin molded body B is also placed on the table 5. Heating and ejection of gas by the hot air heater 6 begins, and when a predetermined temperature and flow rate are reached, the head 3 is moved slightly upstream of the lamination start position, thereby pressing the compression roller 7 against the thermoplastic resin molded body B. At this time, the continuous fiber reinforced thermoplastic resin sheet A is supplied from the sheet conveying device 4 at a predetermined timing, so that immediately after the compression roller 7 is pressed against the thermoplastic resin molded body B, the leading edge of the continuous fiber reinforced thermoplastic resin sheet A is sandwiched between the compression roller 7 and the thermoplastic resin molded body B at the lamination start position.

[0017] As the head 3 moves over the surface of the thermoplastic resin molded body B to be bonded, the continuous fiber-reinforced thermoplastic resin sheet A continues to be supplied. Both the continuous fiber-reinforced thermoplastic resin sheet A and the thermoplastic resin molded body B are heated and then welded together by applying pressure with a compression roller 7. When the welding is completed to the end, the continuous fiber-reinforced thermoplastic resin sheet A is cut with a cutter, and the head 3 is moved to a predetermined position to complete the bonding of the continuous fiber-reinforced thermoplastic resin sheet A. By repeating the same operation as necessary, the continuous fiber-reinforced thermoplastic resin sheet A is laminated on the surface of the thermoplastic resin molded body B to be bonded, thereby obtaining the composite molded body 9 shown in FIG. 2. In the present invention, the hot air heating means is equipped with a nozzle having an elliptical or polygonal cross section, which allows the continuous fiber-reinforced thermoplastic resin sheet A and the thermoplastic resin molded body B to be uniformly heated, resulting in a composite molded body without any unwelded areas.

[0018] The nozzle used in the hot air heating means of the present invention has an elliptical or polygonal cross section. A specific polygonal shape has 3 to 20 vertices. If the number of vertices exceeds 20, manufacturing and processing of the nozzle may become difficult. Furthermore, a polygon having an even number of vertices is preferred, as this allows the continuous fiber-reinforced thermoplastic resin sheet A and the thermoplastic resin molded body B to be uniformly heated and a composite molded body without unwelded parts to be obtained. A quadrilateral, hexagonal, or octagonal shape is more preferred because it allows for easy shape control during manufacturing, and a hexagonal or octagonal shape is most preferred because it allows for easy shape control during manufacturing, allows for the continuous fiber-reinforced thermoplastic resin sheet A and the thermoplastic resin molded body B to be most uniformly heated, and provides excellent weldability.

[0019] The nozzle used in the hot air heating means of the present invention preferably has a cross-sectional major axis that is 1.2 to 10 times the minor axis. This range makes it possible to heat the continuous fiber reinforced thermoplastic resin sheet A and the thermoplastic resin molded product B uniformly to a predetermined temperature, and to obtain a composite molded product without unwelded parts in a shorter time. It is more preferably 1.4 times or more, and more preferably 5 times or less.

[0020] Figure 3 shows an example of a nozzle with an elliptical cross-sectional shape, and Figure 4 shows an example of a nozzle with a polygonal cross-sectional shape. In the present invention, the major axis is the length of the axis that passes through the center of the ellipse or polygon and is the longest, and the minor axis is the length of a line that passes through the center of the ellipse or polygon and is perpendicular to the major axis. In Figures 3 and 4, a and b represent the major axis and minor axis, respectively.

[0021] The nozzle used in the hot air heating means of the present invention preferably has a cross-sectional major axis of 5 mm or more and 50 mm or less. If the major axis is less than 5 mm, the range between the continuous fiber reinforced thermoplastic resin sheet A and the thermoplastic resin molded product B becomes narrow, and it may not be possible to obtain a composite molded product without unwelded parts in a short time. If it exceeds 50 mm, it may be difficult to heat the hot air to the specified temperature. It is more preferable that the major axis is 5 mm or more and 20 mm or less.

[0022] In the continuous fiber-reinforced thermoplastic resin sheet A of the present invention, the reinforcing fibers used for the unidirectionally oriented continuous fibers are preferably carbon fiber, glass fiber, or aramid fiber. Carbon fiber and glass fiber are more preferred, and carbon fiber is most preferred. When carbon fiber is used, the rigidity and strength of the composite molded body can be most efficiently improved, so the amount of continuous fiber-reinforced thermoplastic resin sheet A used can be reduced, and the composite molded body can be obtained in a shorter time.

[0023] In the present invention, it is preferable to use a radiant energy heating means in combination with the hot air heating means, since this allows a composite molded body to be obtained in a shorter time. Examples of the radiant energy heating means include infrared heating and laser heating.

[0024] The continuous fiber-reinforced thermoplastic resin sheet of the present invention preferably has a thickness in the range of 0.05 to 1 mm. It is more preferably 0.2 mm or more, and even more preferably 0.5 mm or less. If the thickness is less than 0.05 mm, the rigidity and strength of the composite molded product may not be sufficiently improved, and the fibers in the continuous fiber-reinforced thermoplastic resin sheet may become disordered, resulting in a decrease in appearance, rigidity, and strength. Furthermore, if the thickness exceeds 1 mm, the accuracy with which the continuous fiber-reinforced thermoplastic resin sheet is shaped relative to the thermoplastic resin molded product may decrease, causing wrinkles in the sheet or the sheet to protrude from the thermoplastic resin molded product, preventing the production of a composite molded product with excellent rigidity, strength, and appearance.

[0025] Examples of the thermoplastic resin in the continuous fiber-reinforced thermoplastic resin sheet A of the present invention include polyamide-based resins (polyamide 6, polyamide 66, etc.), polyester-based resins (polyethylene terephthalate, polybutylene terephthalate, polycarbonate, etc.), polyphenylene ether, polyphenylene sulfide-based resin, polyoxymethylene (polyacetal, etc.), acrylonitrile-butadiene-styrene copolymer, polystyrene, liquid crystal polyester, etc. Polyamide-based resins and polyphenylene sulfide-based resins are preferred because they have excellent weldability with the thermoplastic resin molded body B and allow a composite molded body to be obtained.

[0026] The thermoplastic resin in the continuous fiber reinforced thermoplastic resin sheet A of the present invention may contain a release agent, a stabilizer, an ultraviolet absorber, a flame retardant, a flame retardant assistant, an anti-dripping agent, a lubricant, other thermoplastic resins or thermosetting resins, as long as the effects of the invention are not impaired.

[0027] Examples of the thermoplastic resin in the thermoplastic resin molded product B of the present invention include polyamide resins (polyamide 6, polyamide 66, etc.), polyester resins (polyethylene terephthalate, polybutylene terephthalate, polycarbonate, etc.), polyphenylene ether, polyphenylene sulfide resins, polyoxymethylene (polyacetal, etc.), acrylonitrile-butadiene-styrene copolymers, polystyrene, liquid crystal polyesters, etc. Polyamide resins and polyphenylene sulfide resins are preferred because they provide excellent rigidity and strength to the composite molded product.

[0028] The thermoplastic resin molded product B of the present invention may contain fillers, mold release agents, stabilizers, ultraviolet absorbers, flame retardants, flame retardant assistants, anti-dripping agents, lubricants, other thermoplastic resins, or thermosetting resins, as long as the effects of the invention are not impaired. Either a fibrous filler or a non-fibrous filler may be used as the filler.

[0029] It is also preferable that the thermoplastic resin in the continuous fiber reinforced thermoplastic resin sheet A used in the present invention and the thermoplastic resin in the thermoplastic resin molded product B are both polyamide-based resins. In this case, the continuous fiber reinforced thermoplastic resin sheet A and the thermoplastic resin molded product B are well welded together, and a composite molded product excellent in rigidity and strength can be obtained. [Example]

[0030] The present invention will be described in more detail below with reference to examples. It is not limited to the above.

[0031] First, the methods for measuring physical properties used in the examples and comparative examples will be described.

[0032] (1) Bending property evaluation The composite molding was cut into rectangular test pieces measuring 20 mm x 150 mm x 3.3 mm, and a three-point bending test was carried out under test conditions of a support distance of 64 mm, a bending speed of 1 mm / min, and a temperature of 23°C. The flexural modulus and the flexural strength were measured as the strength at which the test piece first broke.

[0033] (2) Weldability evaluation In the bending property evaluation of (1), the test was continued even after the test piece broke, and the state of breakage of the continuous fiber reinforced thermoplastic resin sheet and the thermoplastic resin molded body was confirmed. If the sheet and the molded body broke while still bonded, it was judged as ◎, if both the sheet and the molded body broke but some peeling of the sheet was observed, it was judged as ○, and if the sheet did not break but peeled from the molded body, it was judged as ×.

[0034] <Production of continuous fiber reinforced thermoplastic resin sheet A> Production Example 1: Production of continuous fiber reinforced thermoplastic resin sheet A (A-1) Toray Industries, Inc.'s Torayca (registered trademark) T700S (12K) carbon fiber was aligned in one direction and introduced into an impregnation die filled with polyamide 6 resin. A continuous fiber-reinforced thermoplastic resin sheet (A-1) with a width of 50 mm, a thickness of 0.28 mm, and a continuous fiber content of 60% by weight was obtained by pultrusion molding.

[0035] <Production of Thermoplastic Resin Molded Product B> Production Example 2: Production of Thermoplastic Resin Molded Product B (B-1) A thermoplastic resin molded body (B-1) measuring 100×150×3 mmt was produced by injection molding using glass fiber reinforced polyamide 6 (CM1011G-45 manufactured by Toray Industries, Inc.).

[0036] Example 1 Using the lamination device shown in Figure 1, the continuous fiber-reinforced thermoplastic resin sheet (A-1) obtained in Production Example 1 was slit into a 20 mm width and placed on sheet conveying means 4, and the thermoplastic resin molded body (B-1) produced in Production Example 2 was placed on platform 5. Next, a nozzle 8 with an elliptical cross-section (shown in Figure 3) with a major axis a of 16 mm and a minor axis b of 8 mm was attached to the tip of hot air heater 6. After adjusting the distance and angle between the nozzle tip and the thermoplastic resin molded body, the welding device was operated under conditions of a hot air temperature of 750°C and a flow rate of 90 L / min to produce a composite molded body. The resulting composite molded body was used to evaluate bending properties and weldability. The results are shown in Table 1.

[0037] <Examples 2 and 3> A composite molding was produced in the same manner as in Example 1, except that the major axis a and minor axis b of the nozzle 8 were changed as shown in Table 1, and then evaluated.

[0038] Example 4 A composite molding was produced and evaluated in the same manner as in Example 1, except that a nozzle with a hexagonal cross section shown in FIG. 4, a major axis a of 20 mm, and a minor axis of 5 mm was used.

[0039] <Example 5> A composite molding was produced and evaluated in the same manner as in Example 1, except that a nozzle with a hexagonal cross section shown in FIG. 4, a major axis a of 20 mm, and a minor axis of 14 mm was used.

[0040] Example 6 A composite molded product was produced in the same manner as in Example 1, except that a nozzle having a rectangular cross section with a major axis of 20 mm and a minor axis of 5 mm was used, and was then evaluated.

[0041] <Comparative Example 1> A composite molded body was produced and evaluated in the same manner as in Example 1, except that a nozzle with a circular cross section and a diameter of 11 mm was used.

[0042] [Table 1]

[0043] As shown in Table 1, the composite molded bodies produced by the methods of Examples 1 to 6 were good in all of bending strength, bending modulus, and weldability. On the other hand, the composite molded body produced by the method of Comparative Example 1 was poor in all of bending strength, bending modulus, and weldability. [Industrial Applicability]

[0044] The method for manufacturing a composite molded body of the present invention can be applied to the production of any composite molded body in which a continuous fiber reinforced thermoplastic resin sheet and a thermoplastic resin molded body are joined and integrated while at least one of them is heated.

[0045] Taking advantage of its excellent properties, it can be used for a variety of purposes, including aircraft parts, automobile parts, electrical and electronic parts, building materials, various containers, daily necessities, household goods and sanitary products. [Explanation of symbols]

[0046] 1. Application device 2. Articulated robots 3. Head 4. Sheet transport means 5.stand 6. Hot air heater 7.Compression roller 8. Nozzle 9.Composite molded body A. Continuous fiber reinforced thermoplastic resin sheet B. Thermoplastic resin molded body a. Major diameter b. Short diameter

Claims

1. A method for manufacturing a composite molded body in which a continuous fiber reinforced thermoplastic resin sheet A, which is made of continuous fibers oriented in one direction and a thermoplastic resin, and a thermoplastic resin molded body B are joined and integrated while at least one of them is heated using a hot air heating means, wherein the hot air heating means is equipped with a nozzle having a hexagonal or octagonal cross section, and the major axis of the nozzle cross section is 1.2 to 5 times the minor axis.

2. The method for producing a composite molded product according to claim 1, wherein the major diameter of the nozzle is 5 mm or more and 50 mm or less.

3. 3. The method for producing a composite molded article according to claim 1, wherein the continuous fibers are carbon fibers.

4. The method for producing a composite molded article according to any one of claims 1 to 3, further comprising the step of using a heating means based on radiant energy.

5. The method for producing a composite molded body according to any one of claims 1 to 4, wherein the thermoplastic resin in the continuous fiber reinforced thermoplastic resin sheet A and the thermoplastic resin in the thermoplastic resin molded body B are both polyamide-based resins.

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