JP2018176444A - Method of molding fiber-reinforced thermoplastic resin molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method of molding a fiber-reinforced thermoplastic resin molded article for precisely molding into a rectangular shape in plan view.SOLUTION: A method for forming a fiber-reinforced thermoplastic resin molded article 10 comprises a projecting portion forming step of forming a projecting portion 18 projecting outwardly at each corner portion 16 of the fiber reinforced thermoplastic resin material 14 formed in a rectangular shape in plan view, while maintaining a temperature higher than a melting point of the fiber-reinforced thermoplastic resin material 14, and a molding step of placing the fiber reinforced thermoplastic resin material 14 on which the projecting portion 18 is formed, on a molding mold 20 having a rectangular cavity 24 in a plan view to press mold it, and forming each corner portion 12 of the fiber-reinforced thermoplastic resin molded body 10 having a rectangular shape in plan view with the projecting portion 18.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of molding a fiber-reinforced thermoplastic resin molded article.

  The first material for forming the base portion of the formed body and the second material for forming the three-dimensional shape portion are heated, and the first material and the second material are formed at the time of press forming. A method for producing a fiber-reinforced thermoplastic resin molded product having a three-dimensional shaped portion on a base portion by integral molding in a mold cavity is conventionally known (see, for example, Patent Document 1).

JP, 2014-188831, A

  However, when the fiber-reinforced thermoplastic resin material is press-formed into a rectangular shape in plan view, it is difficult to accurately form the desired rectangular shape in consideration of the flowability of the fiber-reinforced thermoplastic resin material. That is, it is difficult to precisely form up to each corner of the fiber-reinforced thermoplastic resin molded product which is rectangular in plan view, and establishment of a molding method capable of forming up to each corner precisely is desired.

  Then, an object of this invention is to obtain the formation method of the fiber reinforced thermoplastic resin molded object which can be shape | molded precisely in rectangular shape by planar view.

  In order to achieve the above object, the molding method of a fiber-reinforced thermoplastic resin molded article according to claim 1 of the present invention maintains a temperature higher than the melting point of the fiber-reinforced thermoplastic resin material, in plan view A protrusion forming step of forming a protrusion projecting outward on each corner of the rectangular fiber-reinforced thermoplastic resin material, and the fiber-reinforced thermoplastic resin material having the protrusion formed thereon Forming the respective corners of the fiber-reinforced thermoplastic resin molded product which is disposed in a mold having a rectangular cavity in a plan view and is press-formed, and forming the corners of the fiber-reinforced thermoplastic resin molded body having a rectangular shape in a plan view including.

  According to the invention as set forth in claim 1, in a plan view, projecting portions which project outward are formed at respective corner portions of the fiber reinforced thermoplastic resin material, and at the time of press molding, the fiber reinforcing is carried out by the projecting portions. Each corner of the thermoplastic resin molding is formed. Therefore, the fiber-reinforced thermoplastic resin molded article is accurately formed into a rectangular shape in plan view.

  As described above, according to the present invention, a fiber-reinforced thermoplastic resin molded article can be accurately formed into a rectangular shape in plan view.

(A) It is a top view which shows the fiber reinforced thermoplastic resin material which concerns on this embodiment before press-molding. (B) It is a top view which shows the fiber reinforced thermoplastic resin molded object which concerns on this embodiment after press-molding. (A)-(C) It is explanatory drawing which shows the process of press-molding the fiber reinforced thermoplastic resin material which concerns on this embodiment with a shaping | molding die, and shape | molding the fiber reinforced thermoplastic resin molded object which concerns on this embodiment. (A) It is a top view which shows the fiber reinforced thermoplastic resin material which concerns on the comparative example before pressing. (B) It is a top view which shows the fiber reinforced thermoplastic resin molded object which concerns on the comparative example after press-molding.

  Hereinafter, embodiments according to the present invention will be described in detail based on the drawings. For convenience of explanation, the arrow UP shown in each drawing as appropriate in the drawings is the upward direction of the mold 20, the arrow FR is the forward direction of the mold 20, and the arrow LE is the left direction of the mold 20. It is not limited.

  In addition, the molding method in the present embodiment is a method of molding a fiber-reinforced thermoplastic resin molded body (hereinafter, simply referred to as a “molded body”) 10 which is rectangular in plan view. Therefore, although the molded object 10 which becomes rectangular shape is demonstrated as an example of rectangular shape below, the same may be said even if the molded object 10 is square shape, for example.

  Furthermore, a fiber reinforced thermoplastic resin material (hereinafter simply referred to as "resin material") in which a thermoplastic resin and reinforcing fibers are mixed together by a kneader (not shown), and reinforcing fibers are randomly oriented in the thermoplastic resin. Although 14 is produced, in this embodiment, 5 mass%-50 mass% are preferable, and, as for the content rate of the reinforcing fiber contained in the resin material 14, 10 mass%-50 mass% are more preferable.

  As a thermoplastic resin, for example, polycarbonate (PC) resin, polyamide (PA) resin, polyurethane (PU) resin, polyvinyl chloride resin, acrylonitrile-butadiene-styrene copolymer (ABS) resin, polypropylene (PP) resin, etc. Particularly preferred are PA resin and PP resin, but not limited thereto.

  Examples of reinforcing fibers include aramid fibers, cellulose fibers, nylon fibers, vinylon fibers, polyester fibers, polyolefin fibers, resin fibers such as rayon fibers, carbon fibers (CF), glass fibers (GF), metal fibers, etc. In particular, carbon fibers capable of achieving high mechanical strength are suitable, but not limited thereto. As the reinforcing fibers, various known fibers may be used depending on the purpose.

  First, the molding die 20 of the press in the present embodiment will be described. As shown in FIG. 2, the molding die 20 has a lower die 22 which is a fixed side, and an upper die 26 which is a movable side which moves up and down with respect to the lower die 22. The lower mold 22 is formed with a cavity 24 which is a concave portion in a rectangular shape (rectangular shape) in plan view for molding the molded body 10, and the upper mold 26 is a rectangular shape in a bottom view fitted with the cavity 24. A core 28 which is a (rectangular) convex portion is formed.

  Therefore, as shown in FIG. 2A, the resin material 14 described later is disposed on the central portion of the bottom surface 24B in the cavity 24 of the lower mold 22, as shown in FIGS. 2B and 2C. As shown, while the upper die 26 is lowered, the resin material 14 is press-formed on the lower surface 28A of the core 28 (sandwich is pressed between the bottom surface 24B of the cavity 24 and the lower surface 28A of the core 28). 10 is to be molded (manufactured).

  Next, a molding method for molding (manufacturing) the molded body 10 using the molding die 20 as described above will be described.

  First, a fiber-reinforced thermoplastic resin molded body (hereinafter, simply referred to as a “molded body”) 30 according to a comparative example shown in FIG. 3 will be described. As shown in FIG. 3 (A), a fiber-reinforced thermoplastic resin material (hereinafter simply referred to as “resin material”) 34 for molding (manufacturing) the molded body 30 according to this comparative example is substantially in plan view. It is formed in a rectangular shape.

  The resin material 34 is disposed on the central portion of the bottom surface 24B in the cavity 24 of the lower mold 22 of the mold 20 by a supply means (not shown) such as a robot arm, and the upper mold 26 shown in FIG. The lower surface 28A of the core 28 is pressed. Then, as shown in FIG. 3B, the resin material 34 flows outward (in a direction perpendicular to the vertical direction, such as a front-rear direction or a horizontal direction indicated by an arrow) in a plan view.

  Here, in each corner portion 36, the resin material 34 has a flow velocity slower than that of other portions (the pressure distribution is relatively low). Therefore, as shown in the drawing, each corner portion 32 of the compact 30 cooled (solidified) by the mold 20 while being press-formed and having a temperature lower than the melting point is short in flow length, It is formed in the shape of a circular arc that is convex toward the side (in the shape with missing corners), and the formed body 30 is not formed in the desired rectangular shape as a whole (the formed body 30 is formed in a substantially elliptical shape as a whole) .

  In other words, each corner portion 36 of the resin material 34 does not reach (does not reach) each corner portion 24A of the rectangular shape in plan view in the cavity 24, and is arc-shaped in plan view in each corner portion 32 of the molded body 30. Between the outer edge 32A and each corner 24A in the cavity 24, a space S having a substantially right-angled triangular shape in plan view is formed, and each corner 32 of the molded body 30 has a substantially right-angled shape in plan view. It does not (it does not become a corner).

  On the other hand, the molded object 10 which concerns on this embodiment is shape | molded (manufactured) as follows. First, as shown in FIG. 1 (A), a temperature higher than the melting point of the resin material 14 is maintained by a forming die (not shown) of a press for preform different from the forming die 20, and a plan view is obtained. In the respective rectangular portions 16 (shown by imaginary lines) of the resin material 14 formed into a substantially rectangular shape, projecting portions 18 projecting (extending) outward are integrally formed (protrusion portion forming step).

  The protrusion 18 protrudes in a substantially elliptical shape in a plan view, and is formed in a substantially line symmetrical shape with the major axis as the axis of symmetry. The shape of the projecting portion 18 is not limited to the substantially elliptical shape in plan view in the drawing, and it may be formed in, for example, a substantially rhombus shape in plan view as long as it can compensate for the short flow length of each corner portion 16. It may or may not be formed in a substantially line symmetrical shape. Further, the volume of the resin material 14 is equivalent to the volume of the resin material 34 according to the comparative example, even if the protrusion 18 is formed, and as shown in FIG. Are formed at the same height up to the projection 18.

  As shown in FIG. 2A and FIG. 1B, when the protrusion 18 is integrally formed on each corner 16 of the resin material 14 (when the resin material 14 is formed in a substantially “X” shape in plan view), The resin material 14 is placed on the central portion of the bottom surface 24B in the cavity 24 of the lower mold 22 of the mold 20 by a supply means such as a robot arm. Then, as shown in FIG. 2B, the core 28 of the upper mold 26 of the mold 20 is lowered into the cavity 24 of the lower mold 22, and the resin material 14 is pressed by the lower surface 28A of the core 28. Molding (molding process).

  Then, as shown in FIG. 2 (C) and FIG. 1 (B), the resin material 14 (including the projecting portion 18) is outward (in a direction perpendicular to the vertical direction) in plan view by the molding process. The molded body 10 is cooled (solidified) by the mold 20 until it falls below the melting point while flowing in the front-rear direction, the left-right direction, etc. (Manufacturing) (The above-mentioned defects are formed in a reduced shape).

  That is, by forming the projecting portion 18 at each corner portion 16 of the resin material 14, even if the corner portion 16 has a flow velocity slower than that of other portions (the pressure distribution is relatively low), the flow length The shortness can be compensated, and the resin material 14 (including the projecting portion 18) is efficiently flowed (spread) so as to fill the above-mentioned space portion S (until reaching each corner 24A in the cavity 24). be able to. Therefore, each corner 12 of the molded body 10 can be accurately formed into a substantially right-angled shape in plan view.

  As mentioned above, although the shaping | molding method of the fiber reinforced thermoplastic resin molded object 10 which concerns on this embodiment was demonstrated based on drawing, the molding method of the fiber reinforced thermoplastic resin molded object 10 which concerns on this embodiment is a thing of illustration. The present invention is not limited to the above, and design changes can be made as appropriate without departing from the scope of the present invention. For example, in addition to the thermoplastic resin and the reinforcing fiber, the resin material 14 may contain other components such as an additive, a filler, and a colorant as required.

DESCRIPTION OF SYMBOLS 10 fiber reinforced thermoplastic resin molded object 12 corner | angular part 14 fiber reinforced thermoplastic resin material 16 corner | angular part 18 protrusion part 20 shaping | molding die 24 cavity

Claims (1)

A protrusion forming an outwardly projecting protrusion on each corner of the fiber-reinforced thermoplastic resin material formed in a rectangular shape in plan view while maintaining a temperature higher than the melting point of the fiber-reinforced thermoplastic resin material Part formation process,
A fiber-reinforced thermoplastic resin molded article in which the fiber-reinforced thermoplastic resin material in which the projecting portion is formed is disposed in a mold having a rectangular cavity in a plan view and press-molded to have a rectangular shape in a plan view A forming step of forming each corner with the projection;
And a method of molding a fiber-reinforced thermoplastic resin molded article.