JP2019171739A - Manufacturing method of composite molded product - Google Patents

Abstract

To provide a manufacturing method of a composite molded product that can be integrated in a same mold by a thermoplastic continuous reinforcing fiber substrate made of continuous reinforcing fiber and thermoplastic resin, and molten thermoplastic resin, especially for a purpose of improving a weldability of a welded part in a three-dimensional shape.SOLUTION: A manufacturing method of a composite molded product has a primary molding process for injection-filling molten thermoplastic resin composition C into a first cavity to mold a primary molded product after inserting a thermoplastic continuous reinforcing fiber substrate B made of continuous reinforcing fiber and thermoplastic resin A into a first cavity having a three-dimensional shape set in a mold having a slide mechanism, a process of gate cutting in the mold after primary molding, and a secondary molding process of integrating with the primary molded product by sliding the first cavity into a second cavity together with the primary molded product and disposing the primary molded product in the second cavity and injection-filling a melted thermoplastic resin composition D into the second cavity.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a composite molded article, and in particular, a thermoplastic continuous reinforcing fiber base material composed of continuous reinforcing fibers and a thermoplastic resin and a molten thermoplastic resin composition in a complicated three-dimensional shape and highly The present invention relates to a method for producing a composite molded product that can be welded.

  Various methods of manufacturing composite molded products in which a fiber reinforced resin base material and a thermoplastic resin molded product are integrated are known. When manufacturing a composite molded product integrated in a three-dimensional shape, welding of a welded part is performed. There is a problem with sex. For example, in Patent Document 1, in a method of manufacturing a composite molded article, a continuous reinforcing fiber base is inserted into a first cavity in a mold having a slide mechanism, and a molten thermoplastic resin is injected into the first cavity. After filling and primary molding, the primary molded product is slid and arranged in the second cavity, and the molten thermoplastic resin is injected and filled into the second cavity to be integrated with the primary molded product. A method for manufacturing a composite molded article is disclosed.

JP 2017-119373 A

  However, in the method described in Patent Document 1, a portion that is not welded may be generated depending on the material and molding conditions.

  The object of the present invention is to pay attention to the problems in the prior art as described above, and to make a thermoplastic continuous reinforcing fiber base material composed of continuous reinforcing fibers and a thermoplastic resin, and a molten thermoplastic resin, particularly in a three-dimensional shape. Another object of the present invention is to provide a method for producing a composite molded product that can be integrated in the same mold for the purpose of improving the weldability of the welded portion.

  In order to solve the above-described problem, a first cavity having a three-dimensional shape in which a thermoplastic continuous reinforcing fiber substrate B made of continuous reinforcing fibers and a thermoplastic resin A is set in a mold having a slide mechanism. A first molding step of injection-filling the molten thermoplastic resin composition C into the first cavity and molding a primary molded product after the insertion into the first cavity, and a step of gate-cutting in the mold after the primary molding And the first cavity is slid into the second cavity together with the primary molded product, the primary molded product is disposed in the second cavity, and the thermoplastic resin composition melted in the second cavity A method of manufacturing a composite molded product, comprising: a secondary molding step of injecting and filling the product D and integrating with the primary molded product.

  According to such a manufacturing method, after primary molding, by cutting the gate connected to the molded body, shrinkage and deformation due to the thermoplastic resin in the gate portion can be suppressed, and the thermoplastic continuous generated after welding. It becomes possible to suppress peeling of the reinforcing fiber base material.

  In the present invention, it is preferable to perform gate cutting by mold opening in the gate cutting step. By performing gate cutting by opening the mold, the gate can be cut in a short time without using a special mechanism for the mold, and shrinkage and deformation of the gate portion due to the thermoplastic resin may be suppressed.

  In the present invention, it is preferable to perform gate cutting using a spring installed in the mold. By performing gate cutting using a spring installed in the mold, it is possible to reduce the load on the mold and to perform gate cutting in a short time.

  In the present invention, it is preferable that the thermoplastic continuous reinforcing fiber substrate B is made of a tape-like substrate. When a tape-shaped substrate is used, it is possible to minimize the amount of thermoplastic thermoplastic continuous reinforcing substrate used in the composite molded body and to improve the rigidity and strength of the composite molded body optimally and efficiently. There is a case.

  In the present invention, it is preferable to insert the thermoplastic continuous reinforcing fiber base B from the slit with the mold closed. By inserting the thermoplastic continuous reinforcing fiber base material B from the slit with the mold closed, the thermoplastic continuous reinforcing fiber base material B can be inserted into the complex shaped mold in a short time. While being able to suppress the breakage of the thermoplastic continuous reinforcing fiber base material B at the time of mold installation, the thermoplastic continuous reinforcing fiber base material B may be heated uniformly, and thus the peeling of the manufactured composite molded body may be suppressed. .

  According to the present invention, in a composite molded article made of continuous reinforcing fiber and thermoplastic resin, and an injection resin, the weldability of the welded portion around the gate is improved, and the thermoplastic continuous generated after welding. Peeling of the reinforcing fiber base can be suppressed.

It is the schematic which shows the primary shaping | molding process in the manufacturing method of a composite molded product. It is the schematic which shows the gate cut method by the mold opening after a primary shaping | molding process. It is the schematic which shows the secondary shaping | molding process performed following a primary shaping | molding process. It is a perspective view which shows one example of a primary molded product. It is a perspective view which shows an example of the composite molded product as a secondary molded product.

  Embodiments of the present invention will be described below with reference to the drawings.

  The method for producing a composite molded article according to the present invention has a three-dimensional shape in which a thermoplastic continuous reinforcing fiber substrate B composed of continuous reinforcing fibers and a thermoplastic resin A is set in a mold having a slide mechanism. A primary molding step of molding the primary molded product by injection filling the molten thermoplastic resin composition C into the first cavity after inserting into the first cavity, and in the mold after the primary molding The step of gate cutting, the first cavity is slid into the second cavity together with the primary molded product, the primary molded product is placed in the second cavity, and is melted in the second cavity. It consists of a secondary molding step in which the thermoplastic resin composition D is injection-filled and integrated with the primary molded product. From the thermoplastic continuous reinforcing fiber substrate B, the thermoplastic resin composition C, and the thermoplastic resin composition D A composite molded product is formed

(1) Primary molding process (molding of primary molded products)
The metal mold | die used for the manufacturing method of the composite molded product which concerns on this invention is comprised as shown, for example to FIG. 1 (A). As shown in FIG. 1 (A), the mold (1) in a state where the mold is opened, the mold (1) is composed of a plurality of constituent members. Consists of an upper mold (2) and a lower mold (3). The mold (1) includes a slide mechanism as will be described later. In this embodiment, the upper mold (2) has a space for forming a first cavity (4) having a three-dimensional shape, and the lower mold (3) has a thermoplastic resin composition C. The injection resin injection path (5) is provided. In this embodiment, the first cavity (4) is a space having a narrow plate-like cross section, which extends in a ring shape or as a part of the ring shape, and a longitudinal section shown in the drawing in a part of the extended portion. It is formed so that the posture on the surface, especially the inclination, changes.

  In the state where the mold (1) is opened, as shown in FIG. 1 (B), the continuous reinforcing fiber and the thermoplastic are placed in the first cavity (4) set in the mold (1). A thermoplastic continuous reinforcing fiber base (6) made of resin A is inserted. At this time, the continuous reinforcing fiber base (6) inserted into the first cavity (4) is fixed to a fixture such as a pin (not shown) in the first cavity (4) until, for example, the next mold closing. Can also be fixed. In this embodiment, the thermoplastic continuous reinforcing fiber base material (6) is a unidirectional base material that extends in a tape shape and has continuous reinforcing fibers (for example, continuous carbon fibers) arranged in one direction in the tape-like longitudinal direction. It is configured.

  After the thermoplastic continuous reinforcing fiber substrate (6) is inserted into the first cavity 4, as shown in FIG. 1 (C), the mold (1) is closed and the thermoplastic continuous reinforcing fiber substrate ( 6) is held in the first cavity (4). The mold (1) is heated to a predetermined temperature and provided in the lower mold (3) as shown in FIG. 1 (D) in the first cavity (4) of the closed mold (1). The thermoplastic resin composition C (7) is injected and filled through the injection resin injection path (5), and the primary molded product (8) is formed.

  For example, a thermoplastic continuous reinforcing fiber base material in the form of a tape containing thermoplastic resin A (matrix resin) of the thermoplastic continuous reinforcing fiber base material (6) made of polyamide 6 and containing 50% by volume of carbon fibers as reinforcing fibers is used. When the glass fiber 45% reinforced polyamide 6 is used as the thermoplastic resin composition C (7), the cylinder temperature of the injection molding machine is 280 ° C., the temperature of the mold (1) is about 110 ° C., the injection pressure is 150 MPa, The pressure is set to 60 MPa, and the primary molded product (8) is shaped and molded by the heat of the filled thermoplastic resin composition C (7), the resin pressure, and the heat of the mold (1).

  The temperature of the mold (1) is preferably 90 to 140 ° C, and more preferably 100 to 120 ° C. If the mold temperature is less than 90 ° C, the weld may be insufficient and a peeling part may occur. If the mold temperature exceeds 150 ° C, the shrinkage of the resin will increase, resulting in a peeling part. There is.

  The injection pressure is preferably 50 to 200 MPa, more preferably 80 to 150 MPa. When the injection pressure is less than 50 MPa, welding may be insufficient and a peeled portion may be generated. When the injection pressure exceeds 200 MPa, the thermoplastic continuous reinforcing fiber base material may be broken by the resin pressure.

  The holding pressure is preferably 40 to 180 MPa, and more preferably 50 to 150 MPa. When the holding pressure is less than 40 MPa, the thermoplastic resin composition is not sufficiently filled, and in particular, the shrinkage may increase due to the shrinkage at the gate portion. When the holding pressure exceeds 180 MPa, the resin pressure increases the heat. The plastic continuous reinforcing fiber base material may break.

  In this primary molding step, the thermoplastic continuous reinforcing fiber base (6) inserted into a predetermined position in the first cavity (4) having a three-dimensional shape is injected into the first cavity (4). The thermoplastic resin composition C (7) to be filled is pressed against the inner surface of the first cavity (4) by the injection resin pressure and accurately shaped into a predetermined three-dimensional shape. At the same time, the thermoplastic resin composition C is welded. Then, the three-dimensional primary molded product (8) in which the continuous reinforcing fiber base (6) and the thermoplastic resin composition B are integrated is molded with high accuracy.

(2) Step of performing gate cutting in the mold after primary molding As a mold structure, a spring is provided between the upper mold (2) provided with a gate cut mechanism as shown in FIG. 2 and the gate cut plate (9). (10) is installed, and the upper die (2) opens after the primary molding, and the first die is also opened between the upper die (2) and the gate cut plate (9) by the reaction force of the spring (10). The cavity (4) and the gate (11) are separated and gate cut is performed to obtain a primary molded product (8) from which the gate (11) is cut off.

(3) Secondary molding step (molding of a composite molded product as a secondary molded product)
Subsequent to the gate cutting step in the above mold, a secondary molding step is performed using the same mold (1), for example, as shown in FIG. As shown in FIG. 3 (A), the mold (1) is opened after the primary molding, and FIG. 3 (B) (a cross-sectional view viewed from a direction perpendicular to the direction of FIG. 3 (A) (direction different by 90 degrees)). As shown in FIG. 4, the mold part (12) is rotated with respect to the mold part (13) as shown by the arrow by the slide mechanism (or slide and rotation mechanism) of the mold 1 and is moved to the near side in the drawing. By sliding, the mold part (14) is opened with respect to the mold parts (12) and (13).

  Next, as shown in FIG. 3 (C), the mold (1) is closed, and the first cavity (4) is slid into the mold (1) together with the primary molded product (8). The second cavity (15) for secondary molding is set, and the primary molded product (8) is arranged at a predetermined position in the second cavity (15), and the second cavity (15) The thermoplastic resin composition D (17) is injected through the injection resin injection path (16).

  When the thermoplastic resin composition D (17) is made of 45% glass fiber reinforced polyamide 6, for example, the cylinder temperature of the injection molding machine is 280 ° C., the temperature of the mold 1 is 110 ° C., the injection pressure is 150 MPa, and the holding pressure is Set to 100 MPa. The temperature of the mold 1 is preferably 90 to 140 ° C, and more preferably 100 to 120 ° C. If the mold temperature is less than 90 ° C, the weld may be insufficient and a peeling part may occur. If the mold temperature exceeds 150 ° C, the shrinkage of the resin will increase, resulting in a peeling part. There is.

  The injection pressure is preferably 50 to 200 MPa, more preferably 80 to 150 MPa. When the injection pressure is less than 50 MPa, welding may be insufficient and a peeled portion may be generated. When the injection pressure exceeds 200 MPa, the thermoplastic continuous reinforcing fiber base material may be broken by the resin pressure.

  The holding pressure is preferably 40 to 180 MPa, and more preferably 50 to 150 MPa. When the holding pressure is less than 40 MPa, the thermoplastic resin composition is not sufficiently filled, and in particular, the shrinkage may increase due to the shrinkage at the gate portion. When the holding pressure exceeds 180 MPa, the resin pressure increases the heat. The plastic continuous reinforcing fiber base material may break.

  In this way, the thermoplastic resin composition D (17) and the primary molded product (8) are integrated to form a composite molded product (18) as a secondary molded product.

  As shown in FIG. 3D, the molded composite product (18) is taken out by opening the mold (1). At this time, an extruding push pin (19) or the like may be provided in the mold (1) so that it can be taken out more easily. Note that the composite molded product (18) taken out in FIG. 3 (D) is provided with a one-dot chain line, and there is a portion of the composite molded product (18) symmetrically on the opposite side to the one-dot chain line. This is to show one shape example of the composite molded product (18).

  In such a secondary molding step, a primary molded product (8) having a three-dimensional shape with high accuracy is formed in the primary molding step, and the primary molded product molded with high accuracy first. When (8) is integrated with the thermoplastic resin composition D (17) injected and filled in the second cavity (14), the shape does not collapse or flow out. It is integrated with the filled thermoplastic resin composition D (17) with a high bonding strength at a predetermined position, that is, in a state of being positioned with high accuracy. Therefore, in the composite molded product (18) as the secondary molded product to be finally molded, the primary molded product (8) having a three-dimensional shape, in particular, the thermoplastic continuous constituting the primary molded product (8). A composite molded article (18) in which the reinforcing fiber base (6) is integrated at a predetermined target position with high accuracy and high bonding strength is realized.

  An example of a molded product molded by the molding process as described above is shown in FIG. FIG. 5 shows an example of a final composite molded product (21) molded by the secondary molding process. As illustrated in FIG. 5, the present invention has a complicated three-dimensional shape, and a thermoplastic continuous with high accuracy and high bonding strength to a desired portion of the three-dimensional shape, particularly a desired portion having a three-dimensional shape. A composite molded product in which the reinforcing fiber base is integrated can be obtained.

  The method for producing a composite molded product according to the present invention is a method for producing any composite molded product in which a thermoplastic continuous reinforcing fiber base material is desired to be integrated with an injection resin molded product in a three-dimensional shape with high bonding strength and high accuracy. It is applicable to.

DESCRIPTION OF SYMBOLS 1 Mold 2 Upper mold 3 Lower mold 4 1st cavity 5 Injection resin injection path 6 Continuous reinforcement fiber base material 7 Molten thermoplastic resin composition C
8 Primary molded product 9 Gate cut plate 10 Spring 11 Gate 12, 13, 14 Mold part 15 Second cavity 16 Injection resin injection path 17 Molten thermoplastic resin composition D
18 Composite molded product 19 Extruded pin 20 Primary molded product 21 Composite molded product

Claims (5)

  After inserting a thermoplastic continuous reinforcing fiber substrate B made of continuous reinforcing fibers and thermoplastic resin A into a first cavity having a three-dimensional shape set in a mold having a slide mechanism, the first A primary molding step of injection-filling a molten thermoplastic resin composition C into one cavity to mold a primary molded product, a step of gate-cutting in the mold after primary molding, and the first cavity The first molded product is slid into the second cavity together with the primary molded product, the primary molded product is placed in the second cavity, and the molten thermoplastic resin composition D is injected and filled in the second cavity. A method for producing a composite molded product, comprising: a secondary molding step that is integrated with the primary molded product.   2. The method for producing a composite molded article according to claim 1, wherein the gate cutting is performed by mold opening in the step of gate cutting.   The method for producing a composite molded article according to claim 1 or 2, wherein in the step of performing gate cutting, gate cutting is performed using a spring.   The manufacturing method of the composite molded product in any one of Claims 1-3 in which the thermoplastic continuous reinforcement fiber base material B consists of a tape-shaped base material.   The manufacturing method of the composite molded article in any one of Claims 1-4 which inserts the thermoplastic continuous reinforcement fiber base material B from a slit part in the state which the metal mold | die closed.