JPH04125134A - Production of fiber reinforced resin molding - Google Patents

Abstract

PURPOSE:To perform shaping of fiber and molding in the same mold and to rationalize a producing process by placing the fiber reinforcing material slightly larger than a molding in an opened mold and closing the mold to perform shaping and removing the part of the fiber reinforcing material projected from the mold cavity and thereafter introducing resin and integrally molding the fiber reinforcing material and resin. CONSTITUTION:The fiber reinforcing material 2 slightly larger than the area necessary for shaping is placed on the bottom plate 1 of a mold. Then the fiber reinforcing material 2 is pinched between a top plate 7 and the bottom plate 1 so that the unnecessary part 6 of the fiber reinforcing material is projected to the outside of the mold. This unnecessary part 6 of the fiber reinforcing material is cut by a shearing cutter. Thereafter one part of the cut surface is secured as a flow path of resin. A wall 8 for sealing is closed to seal the other part and thereafter resin is sent into the mold through a pipe 4 by a resin injector 3 and cured according to the properties of resin. After curing is completed, the mold is opened to take out a fiber reinforced resin molding. Thereby a molding process is drastically rationalized and the producing cost of the fiber reinforced resin molding is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a method for manufacturing a fiber-reinforced resin molded article, and more specifically, the present invention relates to a method for manufacturing a fiber-reinforced resin molded article, and more specifically, it is a method for manufacturing a fiber-reinforced resin molded article. The present invention relates to a method for advantageously manufacturing the molded body by continuously performing the molding in the same mold.

[Prior Art] In molding by resin injection, resin transfer molding, SR M (Structural Resin Injection Molding) molding, etc., a fiber reinforced material is placed in an open mold, the mold is closed,
After that, resin is injected to produce a fiber-reinforced resin molded body. Fiber mats, cloth, etc. are used as the fiber reinforcing material. These products are usually distributed in the form of flat rolls rolled into a raw shape. If the shape of the fiber-reinforced resin molded product to be manufactured is a flat plate, the above-mentioned fiber-reinforced material may be cut to match the shape of the mold and placed in the mold. However, when trying to mold a general three-dimensional shape, the fiber reinforced material is shaped into that shape, the unnecessary parts of the ends are cut off, and then placed in a mold, and then It was molded by injecting resin. As methods for shaping the fiber reinforced material, there are mainly thermoforming methods and spraying methods.

In the thermoforming method, a thermoplastic binder is added into the fiber layer in advance, and during shaping, the binder is melted by heating and deformed into the desired shape, and then cooled to solidify the binder to form the desired shape. Fixed to. For this purpose, a heating device is used to melt the binder in the fiber layer;
A press device is required to give the shape, and a heat removal device is required for fixing. Normally, a water-cooled or air-cooled cooling press device is used to perform pressing and heat removal at the same time.

In addition, in the method of spraying, air is sucked from one side of a perforated plate (for example, punched metal, wire mesh, etc.) that has the same shape as the shape to be shaped, and continuous strands are formed from the other side. The pieces cut to about 10 cm are stacked on the perforated plate using this air flow. At this time, a binder is sprayed to fix the laminated fibers.

[Problems to be Solved by the Invention] However, according to the former method for shaping fibers, two molds are required for one type of molded product, one for shaping and one for molding, and the manufacturing process is also complicated. Become. Moreover, it cannot be said that it is advantageous in terms of energy, as it requires heating and cooling during shaping, and then heating during molding. Furthermore, even with the latter method, the manufacturing process is still complicated, and in addition, the working environment is not good, as the cut short fibers are likely to scatter.

[Means for Solving the Problems] In view of the above circumstances, the present inventors have made extensive studies and found that the manufacturing process can be significantly streamlined by performing fiber shaping and molding in the same mold. The invention has been completed. That is, an object of the present invention is to provide a manufacturing method that eliminates the need for a heating device for melting a binder, a press device for imparting a shape, and a heat removal device for fixing, which were necessary in conventional thermoforming methods. The purpose of the present invention is to provide a production method that is advantageous in terms of energy efficiency, in which the energy heated during shaping can be used directly during molding.Furthermore, it eliminates the need for a binder used in shaping, thereby reducing the permeation of the resin. The purpose of the present invention is to provide a manufacturing method that improves properties and wettability, and at the same time, provides a manufacturing method that does not cause the scattering of short fibers that occurs in the spraying method.

The purpose of the present invention is to produce a fiber-reinforced resin molded product by placing a fiber-reinforced material thicker than the molded product in an open mold, closing the mold to shape the fiber-reinforced material, and This is achieved by a method for manufacturing a fiber-reinforced resin molded body, in which the portion protruding from the mold cavity is removed, and further resin is injected to integrally mold the fiber-reinforced material and resin.

The present invention will be explained in more detail below.

The fiber-reinforced resin referred to in the present invention is a resin reinforced with fibers, and the fibers are made of materials selected from inorganic and organic materials, such as glass fibers, carbon fibers, alumina fibers, boron fibers, silicon fibers, Examples include aromatic polyamide fibers and polyester fibers. The length of the fiber is not particularly limited, but in order to increase mechanical strength, a longer fiber is preferable.

As the form of the fiber reinforcement material, a mat, a woven fabric, or a combination thereof is used. From the viewpoint of ease of shaping, it is preferable to use a material in which the fibers can easily move depending on the shape of the mold, such as a randomly laminated mat of long fibers. When shaping fibers, depending on the shape of the shaping, there are parts where the fibers move a lot and parts where it doesn't. Taking these into consideration, at least a part of the periphery of the fiber reinforcement material is shaped into a skein, etc. It is preferable to fix it by.

The mold used in the present invention has, for example, upper and lower discs that have the same shape as the cavity corresponding to the shape to be molded and whose peripheral edges are the same or slightly larger in shape, and the fibers are sandwiched between these. After that, it is necessary that the fibers protruding from the edges of the disk can be cut by some means that comes into contact with the edges. As the cutting method, a method using shearing force is preferably used. Specifically, these include scissors, clippers, shear cutting machines, etc., and shear cutting machines that rotate polygonal blades with gentle arcs on each side (for example,
A cutting machine "'BMIOI" manufactured by KURIS, etc. may also be mentioned. Alternatively, a cutting portion may be provided at the end of the mold itself. Although the cut fibers are less likely to fly away when sprayed, it is preferable to remove them with a vacuum suction machine from the viewpoint of the working environment and efficiency of the work. The process of cutting and removing fibers can be easily automated using a robot or the like. Depending on the shape in which the fibers are sandwiched between the molds, the cut surfaces of the fibers may face upward or sideways, but either direction is acceptable.

Once the fibers have been cut and removed, a mold is applied to sandwich the placed fiber reinforcement material and a mold to seal the cavity. It is preferable that these molds have a structure in which they are fitted together in order to ensure the airtightness of the cavity. Furthermore, it is preferable to have a structure in which a resin injection device is integrally attached to a mold for sealing the cavity or a mold that faces the mold to be fitted thereto, in order to rationalize the structure of the equipment. In consideration of the operability of the equipment and the workability of molding, it is preferable that the resin injection port be located within the parting surface of the mold or within the cavity surface. The resin may be injected from a part of the cut surface of the fiber, or from a part of the surface on either side of the fiber layer.

The material of the mold is not particularly limited, but at least the part involved in cutting the fibers is preferably made of hard materials such as metal or ceramics. The surface of the mold cavity is preferably finished smooth by polishing or the like. This is important in improving the surface smoothness of the molded article according to the method of the present invention,
It is also important for improving mold releasability during molding.

The matrix resin referred to in the present invention may be either thermoplastic or thermosetting resin, and can be injected into a mold by injection molding, resin injection, transfer molding, reaction injection molding, etc. . In the present invention, it is preferable to inject the resin by reaction injection molding from the viewpoint of good permeability in the fiber layer and high productivity. Thermoplastic, thermosetting, or a combination of these resins that can be molded by a reaction injection molding machine is injected into a mold in the form of a liquid resin raw material. What is liquid resin raw material?
It is a two-component or three-component material that serves as the raw material for the resin, and can be hardened by collision-mixing.

The viscosity of the resin raw material depends on the mold temperature and mixing ratio, but the lower the viscosity at the time of injection after mixing, the better.
Cp or less is preferable. It is preferable that the curing speed is slow when filling the mold, and that the curing speed is rapid after filling is completed. Specifically, the curing time is preferably 10 minutes or less, preferably 5 minutes or less, and more preferably 3 minutes or less. Examples of the resin of the present invention include raw materials for thermosetting resins such as epoxy, vinyl ester, unsaturated polyester, phenol, bismaleimide, urethane, polyurea, and polyisocyanurate, and thermoplastic resins such as polyamide and polycarbonate. In addition, norbornene type polymerizable monomers, and allyl, vinyl, acrylic, and methacrylic type carbon-
Also included are thermosetting resins polymerized from monomers and oligomers having carbon double bonds. Additives such as a reactive diluent, a catalyst, and an internal mold release agent may be appropriately added to these resins.

Next, one method of manufacturing the fiber-reinforced resin molded article of the present invention will be explained using the drawings.

First, as shown in FIG. 1, a fiber reinforced material 2 whose area is slightly larger than the area required for shaping is placed on the lower plate 1 of the mold.

Next, as shown in FIG. 2, the fiber reinforcing material 2 is sandwiched between the upper plate 7 and the lower plate 1 so that the portion 6 not requiring fiber reinforcing material protrudes outside the mold. When this fiber-reinforced material unnecessary portion 6 is cut using the method described above, the state shown in FIG. 3 is obtained. After that, a part of the cut surface is secured as a flow path for the resin, and after closing the sealing wall 8 for sealing the other part, the resin is passed through the pipe 4 and sent into the mold by the resin injection device 3. harden according to the properties of the material. This state is shown in FIG. After curing is completed, the mold is opened and the fiber-reinforced resin molded article is taken out. If necessary, a portion of the fiber-reinforced resin molded body taken out may be cut to form a predetermined shape.

[Examples] The present invention will be further explained below using Examples, but the present invention is not limited to the Examples unless the gist thereof is exceeded.

As a mold, the dimensions of the upper board are 300mm long and 300mm wide.
A metal plate was used in which the dimensions of the lower plate were 400 mm in length and 400 mm in width, and the distance between the two plates was 1 mm when the glass mat was inserted. A glass mat cut to an appropriate size so as to protrude from the mold was inserted into the mold, and the mat was fixed so that the distance between the upper and lower plates was 1 mm. After removing the glass mat protruding from the mold with a clipper while vacuuming at 4 degrees, a part of the cut surface has a channel for the gate, and the opposite side to the gate has air in the cavity and excess resin. A mold that had been processed to provide a pool for the liquid to escape was fitted onto the outer periphery of the upper plate, and these molds were then sandwiched between the surfaces of the lower plate to seal the cavity. The temperature of the mold is 120°C
I kept it.

The resins include bisphenol A type diglycidyl ether (hereinafter abbreviated as A) and isophorone diamine (hereinafter abbreviated as B).
) was heated to about 50'C.

The resins A and B were mixed at a weight ratio of 100127 and injected into the mold using a mixing head attached to the lower plate. After the resin had hardened, the mold was opened and the molded product was taken out.

[Effects of the Invention] By employing the manufacturing method of the present invention, the molding process can be significantly streamlined, which greatly helps in reducing the manufacturing cost of fiber-reinforced resin molded bodies.

[Brief explanation of the drawing]

FIG. 1 and FIG. 4 are explanatory diagrams showing one example of the manufacturing method of the present invention. 1: Lower panel 2: Fiber reinforced material 3: Resin injection device 4: Pipe 5: Section requiring woven fiber material 6: Section not requiring fiber reinforcing material 7: Upper panel 8: Sealing mold

Claims (5)

[Claims] (1) When manufacturing a fiber-reinforced resin molded article, a fiber-reinforced material larger than the molded article is placed in an open mold, the mold is closed and shaped, and the portion of the fiber-reinforced material that protrudes from the mold cavity 1. A method for producing a fiber-reinforced resin molded article, which comprises removing the fiber-reinforced material and further injecting resin to integrally mold the fiber-reinforced material and the resin. (2) The fiber according to claim 1, wherein the mold for sandwiching the placed fiber reinforcement material and the mold for sealing the cavity after cutting and removing the fibers protruding from the mold cavity are fitted together. A method for producing a reinforced resin molded body. (3) The method according to claim 1, wherein at least a portion of the periphery of the fiber reinforcement material is fixed, and then the mold is closed and shaped. (4) The method according to claim 1 or 2, wherein the mold for sealing the mold cavity or a mold to be fitted with the mold and a mold facing the mold and the resin injection port are integrally attached. (5) The method according to any one of claims 1 to 3, wherein two or more reactive raw material resins are mixed and immediately injected.