JPH07214677A - Method and mold for molding fiber reinforced plastic equipped with surface layer material - Google Patents

Abstract

PURPOSE:To solve various problems such that productivity is low, working environment is bad, a homogenous product is defficult to obtain or the material quality of a gel coat layer is limited being difficult points of fiber reinforced plastic equipped with a gel coat layer. CONSTITUTION:In a molding method, in place of a gel coat layer forming process, a surface material preformed into the shape conforming to that of the inner wall surface of a mold is applied to the inner wall surface of the mold. After a fibrous reinforcing material is arranged to the interior of the mold, a plastic material is injected in the hermetically closed mold to be integrally molded along with the surface layer material. A vacuum suction chamber 22 for applying the surface layer material having vacuum moldability to the inner wall surface of the mold and a clamp means 24 fixing the peripheral edge part of the surface layer material to the inner wall surface of the mold in a close contact state are provided to the mold. A part of the wall of the mold is constituted of a flexible material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a fiber reinforced plastic having a surface layer material for integrally forming a cosmetic / protective skin layer with a molded article without using the conventional gel coating method. And a mold.

[0002]

2. Description of the Related Art Molded products made of fiber reinforced plastic (FRP) are used in order to prevent the fibrous reinforcing material from appearing on the surface of the molded product so as not to be unsightly and to improve the appearance and physical properties of the surface of the molded product. A gel coat layer is provided which is made of a simple substance of resin and does not contain a fibrous reinforcing material. In order to form this gel coat layer, first, a gel-like composition comprising, for example, an unsaturated polyester and a curing agent therefor is brushed or sprayed on the inner wall surface of the mold. After the gel coat layer is cured, a FRP layer having a required thickness is formed on the surface of the gel coat layer by a known hand lay-up method or spray-up method, whereby a product coated with the gel coat layer is completed. Alternatively, a method is also used in which a fibrous reinforcing material is disposed on the upper surface of the gel coat layer, the molding die is sealed, and a plastic material is pressure-injected by a dedicated injection machine. The present inventor
With regard to the molding method by such pressure injection, a new FRP molding improved so that a low injection pressure of atmospheric pressure or less is sufficient and mold cost can be saved, and "void" does not occur even in thin products. He developed the technology and applied for a patent as "Japanese Patent Application No. 2-108221". As a technique for casting a plastic material integrally with a skin material, for example, as a manufacturing method for an automobile interior material, first, a plastic sheet such as a vinyl chloride sheet is vacuum-formed to follow the outer shape of the molded product. A method is known in which a skin material having a shape is formed, the skin material is applied to an inner wall surface of a molding die, and a foamable polyurethane resin is filled in the die.

[0003]

However, the conventional method of forming the gel coat layer on the surface of the mold in advance prior to filling the plastic material has a number of problems to be improved as listed below. . (1) It takes 1 to several hours to wait for the gel coat layer to cure. (2) The work of manually providing the gel coat layer is extremely inefficient, including the work of masking the unnecessary portions for application. (3) Needless to say, the worker is exposed to the environment in which the volatile harmful substance contained in the gel coat composition drifts, which is extremely unfavorable for hygiene. (4) The gel coat layer formed by hand tends to have an uneven thickness, and it is difficult to form a homogeneous molded product. (5) Since the gel coat layers have different thicknesses, the required curing time varies, which makes it difficult to smoothly manage the production process. (6) Although gel coat compositions having various properties have been developed so as to better suit the respective uses of various FRP products, at present, there is a limit to the variety of those properties. is there. Therefore, the purpose of the present invention is a difficulty in the production method of the conventional fiber-reinforced plastic product provided with a gel coat layer, low production efficiency, poor working environment, difficult to obtain a homogeneous product, even a gel coat layer with a corner, By utilizing the above-mentioned prior invention, various problems such as lack of variety of materials for imparting optimum surface characteristics to individual uses of molded articles can be solved by using the surface layer material. It is to provide a molding method and a molding die of the fiber-reinforced plastic provided.

[0004]

[Means for Solving the Problems] A method for molding a fiber-reinforced plastic having a surface layer material according to the present invention for attaining the above-mentioned object is as follows:
A method of integrating a surface layer material for beauty / protection, in which a surface layer material having a shape capable of being adhered to an inner wall surface of a molding die for molding a fiber reinforced plastic is used instead of the conventional gel coat layer forming step. Preliminarily prepared, the step of attaching this surface layer material to the inner wall surface of the molding die, the step of disposing a fibrous reinforcing material in the molding die, the molding die is sealed and a plastic material is press-fitted, and the surface layer The material is formed integrally with the material. Then, as a mold for molding the fiber-reinforced plastic, a mold having a function similar to a vacuum mold for sucking a sheet or thin plate-like surface layer material by vacuum suction and adsorbing it to the inner wall surface of the mold is used, and a conventional gel coat layer is used. Instead of the step of forming, the sheet-like surface layer material may be attached to the inner wall surface of the forming die by vacuum suction. Further, the molding die according to the present invention comprises a molding die body A having a split structure,
In order to attach a sheet or thin plate-like surface layer material B having vacuum formability to at least a part of the inner wall surface of the forming die body A by vacuum suction, the peripheral edge portion of the surface layer material B is attached to the forming die body A. Clamping means 24 for fixing in close contact with the mold matching surface or the inner wall surface of the mold, and a plurality of intake holes 21 provided in a portion of the mold wall of the molding die main body A to which the surface layer material B is attached, The vacuum suction chamber 22 is attached to the outer surface of the mold wall so as to cover the intake hole 21 of FIG. A mold clamping vacuum circuit 4 for clamping the mold by the atmospheric pressure is provided around the mold matching surface of the mold main body A, and a part of the mold wall is made of a flexible material. It is preferable that a part of the mold wall be reversibly bulged and deformed by the injection pressure.

[0005]

The method for molding a fiber reinforced plastic having a surface layer material according to the present invention includes a conventional surface layer material forming step in which a gel coat layer is formed in advance on the inner wall surface of the molding die of the fiber reinforced plastic. An outer shell-shaped surface layer material formed into a shape that follows the wall surface shape was prepared, and this surface layer material was replaced with a step of attaching the surface layer material to the inner wall surface of the mold. Therefore, the above-mentioned various problems (1) to (6) derived from the step of forming the gel coat layer are almost eliminated, and the material selection range of the surface layer material is significantly expanded. Further, the surface layer material can be made extremely efficiently by making full use of various known plastic molding techniques. If a forming die having a function similar to that of the vacuum forming die according to the present invention is used, the forming die for the surface layer material becomes unnecessary, and the labor for attaching the surface layer material to the inner wall surface of the die can be saved. Furthermore, a mold clamping vacuum circuit 4 is provided around the mold matching surface of a mold having a divided structure to enable mold clamping by atmospheric pressure, and a part of the mold wall is made of a flexible material, and is made of plastic. By adopting a structure in which a part of the mold wall can be reversibly bulged and deformed by the material injection pressure, the mold clamping mechanism required in the prior art becomes unnecessary, and troublesome mold clamping and mold opening work are performed. Remarkable labor saving. Also, since a low mold clamping pressure of atmospheric pressure or less is sufficient, a significant reduction in mold manufacturing cost and a reduction in mold weight can be achieved. Further, it is not necessary to separately prepare a mold for the surface layer material.

[0006]

EXAMPLE A first example in which the present invention is applied to a case of molding a cover body made of FRP will be described below with reference to FIGS. First, in FIGS. 1 and 2 showing the structure of the molding die body A, 1 is a lower mold made of FRP having sufficient rigidity. In this case, isophthalic acid type, bisphenol type, or vinyl ester type is used. It is manufactured by a conventional method using polyester such as and the like, and glass fiber chopped strand mat.

A molding cavity 2 is formed in the lower mold 1 as shown in FIG. A peripheral edge of the molding cavity 2 is provided with an edge portion 2a that gradually becomes shallower like a knife edge. Further, a wooden peripheral reinforcing material 3 is embedded in a portion of the lower mold 1 where the peripheral portion has an increased thickness. Reference numeral 4 denotes a mold clamping vacuum circuit, which is provided around the upper surface of the peripheral edge of the lower mold 1 and serves as a decompression seal portion of the molding die main body A, and has a shallow groove shape having a predetermined width. On the bottom surface of this groove, two packing grooves 5a, 5a for mounting the rectangular rod-shaped mold clamping packing 5 are provided in parallel at a predetermined interval over the entire length of the groove.

The mold clamping packing 5 has its lower end part fitted in the packing groove 5a, and its upper end side slightly protrudes from the mold matching surface of the lower mold 1. Reference numeral 6 denotes a pressure reducing pipe connected to the lower mold 1 so as to communicate with the mold clamping vacuum circuit 4 and connected to a pressure reducing device described later. Reference numeral 7 denotes a groove-shaped molding vacuum circuit provided around the mold matching surface of the lower mold 1, which is located inside the mold clamping vacuum circuit 4 and communicates with the molding cavity 2 via the edge portion 2a. The edge portion 2a has a height within a range of 0.1 to 0.5 mm and a length within a range of 10 to 60 mm according to the size and shape of the molding die.

Further, on the upper surface of the lower mold 1, a fitting groove 9a into which a long sealing material 9 is fitted is provided around the edge portion 2a. The upper end of the sealing material 9 is made to project somewhat above the mold matching surface of the lower mold 1. Further, on the mold matching surface of the lower mold 1, an engaging projection 11 for positioning the upper mold 10 is provided at a position outside the fitting groove 9a.

The upper mold 10 is made of a flexible material. In this case, the soft polyester is added to the chemically resistant polyester in an amount of 20 to 20.
It is made of 30% flexible polyester resin and chopped strand mat. As shown in FIG. 2, a peripheral portion of the upper die 10 is provided with a reinforcing structure similar to that of the peripheral portion of the lower die 1.

Above the reinforcing peripheral portion, the intake pipe 1
2 is provided so as to communicate with the molding vacuum circuit 7.
In the middle of the upper mold 10, a plastic material injection port 13 into the molding cavity 2 is provided. In addition, an engaging recess 14 into which the engaging projection 11 provided on the lower mold 1 is inserted is provided on the mold matching surface.

B shown in FIG. 1 is an outer shell-like surface layer material for protecting and dressing the surface of a molded product, which is replaced with a lower mold in place of the gel coat layer of the prior art prior to filling with the FRP material. 1
Applied to the inner wall of the. The surface layer material B in this case is made by vacuum forming an acrylic resin plate having a thickness of 0.5 mm inside and outside so as to be brought into close contact with the inner wall surface of the lower mold 1. Further, C shown in FIG. 1 is a glass fiber mat for reinforcement, which is arranged in the molding cavity 2 prior to the injection of the plastic material.

FIG. 5 shows the FR using the molding die body A described above.
It is a sketch of the whole structure of a forming system for forming a P product by what is called a casting method. Reference numeral 31 in the drawing is a molding apparatus main body, which is not shown, but includes a raw material tank for storing plastic materials such as raw material resin and a curing agent, a quantitative feeding device for plastic materials, a decompression device, and a control unit for them, It can be moved by casters. Reference numeral 32 denotes a plastic material mixing head which mixes and discharges a raw material resin and a curing material in a predetermined ratio, and is connected to a raw material tank via a raw material hose 33 and a raw material metering and feeding device.

Reference numeral 34 is a trap for accommodating the plastic material overflowing from the molding die A at the time of molding. The end of the suction pipe 12 extending from the molding die main body A and the start end of the suction pipe 35 connected to the decompression device are provided in the lid portion thereof. And are connected.
A valve 36 is interposed in the pressure reducing pipe 6 for mold clamping.

Next, the operation of the above configuration will be described. First,
With the upper mold 10 removed, the preformed surface layer material B is applied so as to be in close contact with the inner wall surface of the lower mold 1, and then the glass fiber mat C is placed on the surface layer material B. . After that, when the lower mold 1 is covered with the upper mold 10, the pressure reducing device is driven, and the valve 36 provided in the pressure reducing pipe 6 is opened, the pressure in the mold clamping vacuum circuit 4 is reduced. As described above, the upper mold 10 is naturally brought into close contact with the lower mold 1 by the atmospheric pressure without performing a troublesome mold clamping work using the mold clamping tool, and the mold clamping operation is completed very easily.

Therefore, the injection nozzle of the mixing head 32 is inserted into the injection port 13 to fill the molding cavity 2 with a predetermined amount of liquid plastic material. At this time, the molding vacuum circuit 7 is communicated with the atmosphere. However, when the material viscosity is extremely high, a slight negative pressure is applied to assist injection.
This filling pressure is about 0.93 Kg at the inlet 13.
/ Cm ² (about 0.9 atm) inside and outside, 3-6 kg of conventional technology
It is set much lower than / cm ² . Depending on the material of the surface layer material B, the coating of the mold release agent on the mold wall can be omitted for the portion where the surface layer material B is applied.

The injected plastic material is flow-inhibited by the glass fiber mat C arranged in the molding cavity 2, and as shown by the phantom line in FIG. Since the flat part is pushed up slightly, an extremely low injection pressure is sufficient as described above. At the stage where the filling of the plastic material is completed, an unfilled portion of the material remains in the peripheral portion of the molding cavity 2.

Therefore, when the injection port 13 is sealed with a plug (not shown) and the molding vacuum circuit 7 is connected to a decompression device, the air in the unfilled void is sucked out through the edge 2a. Therefore, the plastic material in the molding cavity 2 generally follows the fiber gaps of the glass fiber mat C and spreads throughout the molding cavity 2, and the bulged and deformed upper mold 10 returns to its normal original shape by its deformation restoring force.

The plastic material, which is somewhat overfilled in advance, is then sucked and stored in the trap 34. Thereafter, the plastic material is waited for curing in the depressurized state, but at the stage of curing progress during this period, the plastic material exhibits a strong adhesive force to the surface layer material B. The surface layer material B is firmly joined. Therefore, if the upper mold 10 is removed by releasing the reduced pressure, it is possible to take out a very good molded product with no or almost no air bubbles remaining. The surface material B is FR
It covers the glass fiber mat C appearing on the surface of the P-molded product to give a smooth and beautiful appearance, and also serves to enhance the physical properties of the surface.

Further, the surface layer material B which plays a role of the conventional gel coat layer which has been limited to the polyester resin in the past.
The material of is not limited to acrylic resin, and various types of plastics and rubbers that can be molded by various well-known molding techniques, or non-breathable cloth, etc. can be used for molding products. You can freely select the most suitable one.

Further, according to the above-mentioned molding method, since the injection pressure of the plastic material is not higher than the atmospheric pressure, the molding die main body A also has a simple structure, and the die manufacturing cost is greatly reduced as compared with the conventional technique. Weight reduction is achieved. Since the mold clamping is performed by utilizing the atmospheric pressure by reducing the pressure in the mold clamping vacuum circuit 4, the conventional mold clamping tool becomes unnecessary, and the valve of the pipe connecting the inside of the molding cavity 2 and the pressure reducing device is eliminated. Since opening and closing operations are sufficient, mold clamping and unlocking can be performed extremely efficiently.

3 and 4 show a second embodiment of the present invention. The difference from the first embodiment is that the mold body A has
This is where a function similar to a vacuum forming mold for vacuum forming the surface layer material B is added. That is, the lower mold 1 of the mold main body A is provided with a large number of intake holes 21, and the intake holes 2
The vacuum suction chamber 2 is provided on the outer surface of the mold wall so as to cover 1
2 is assembled. Reference numeral 23 is an intake pipe for connecting the inside of this chamber to a decompression device.

Further, on the mold matching surface of the lower mold 1, the clamping means 2 for fixing the peripheral portion of the surface layer material B to this surface in a close contact state.
4 is provided so as to be located outside the sealing material 9.
The clamping means 24 of this embodiment is provided around the upper surface of the peripheral edge of the lower mold 1 and has an insertion groove 24a for dropping the peripheral edge of the surface material B and the peripheral edge of the surface material B being pushed into this groove. , A plug 24b for fixing the pushed state.

The surface layer material B usable in this embodiment is limited to a sheet or thin plate material having vacuum formability.
For example, various thermoplastic plastic sheets or thin plates typified by vinyl chloride sheets can be mentioned. Further, natural or synthetic leather, a woven fabric or a non-woven fabric to which air permeability is imparted by sticking a thermoplastic film, or synthetic paper can also be used.

The operation of this embodiment utilizes the clamping function and the vacuum forming function of the surface layer material B of the lower mold 1 as shown in FIG.
As can be understood from the above, the surface layer material B is brought into close contact with the inner wall surface of the lower mold 1 while vacuum forming, and then the FRP is formed in the same manner as in the first embodiment. At that time, the sealing material 9 can surely prevent the plastic material from wrapping around between the surface layer material B and the inner wall surface of the mold to enter. According to this molding method, a molding die for the surface layer material B becomes unnecessary, and an apparatus for preliminarily molding the surface layer material B and a labor for molding can be omitted.

In each of the above-described embodiments, the object of the present invention can be achieved even if the detailed structure is appropriately changed. For example, if necessary, the vacuum suction chamber 2 may be provided on the upper mold 10.
2 can be assembled. In that case, the inlet 13
May be moved to an appropriate position on the mold body A. or,
If the shape of the molding cavity 2 is relatively flat, or
When it is sufficient to cover only the flat portion of the surface of the molded product with the surface layer material B, a sheet or thin plate-shaped surface layer material B having almost no elasticity can be used. In that case, as a clamping means for the surface layer material B, the arrangement of the intake holes 21 may be devised so that the peripheral edge portion of the surface layer material B is adsorbed to the inner wall surface of the mold. The molding method is not limited to FRP and is also suitable for molding plastic having poor fluidity during melting. Further, the reinforcing fiber is not limited to glass fiber, of course.

[0027]

As is clear from the above description, the molding method and mold of the fiber reinforced plastic provided with the surface layer material according to the present invention have various excellent effects as listed below. a) The conventional coating work of the gel coat layer, which influences the quality of the molded product, requires skill, but since this work can be omitted,
Even an unskilled worker can easily make a homogeneous product. b) Since the step of manually forming the gel coat layer and the waiting time for curing the gel coat layer can be omitted, the productivity can be significantly improved. c) The problem that harmful volatile substances contained in the gel coat composition deteriorate the working environment is also solved. d) Gelco materials are limited to a few types such as unsaturated polyester, whereas surface layer materials can be various materials as long as they can be molded into a shape that follows the shape of the inner wall surface of the molding die. From the extremely wide range of materials including plastics, cloth, non-woven fabric, leather, etc., you can freely select and use the most suitable one for the application of the product. e) Therefore, it is possible to freely impart, for example, good texture, sophisticated appearance such as patterning and coloring, chemical resistance, weather resistance, etc., which are not required in conventional fiber reinforced plastic products. f) Depending on the material of the surface layer material, it is not necessary to apply a mold release agent to the mold wall portion to which the surface layer material is applied, so that labor and cost can be saved accordingly. g) Since the molding technique of the above-mentioned prior invention by the inventor of the present application is also applied to the present invention, defective products such as "voids" are hardly generated even if the molded products are extremely thin. h) Needless to say, the low-pressure injection of the plastic material and the elimination of the mold clamping device make the molding die inexpensive and lightweight.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a structure of a mold body and a surface material, showing a first embodiment of the present invention.

FIG. 2 is an enlarged vertical cross-sectional view of the main part of the molding die body immediately after the molding is completed.

FIG. 3 is a view, corresponding to FIG. 1, showing a second embodiment of the present invention.

FIG. 4 is a view corresponding to FIG.

FIG. 5 is a sketch of the overall configuration of the molding system including the mold body.

[Explanation of symbols]

 A molding die B surface layer material C glass fiber mat 1 lower die 2 molding cavity 2a edge portion 3 peripheral reinforcement material 4 vacuum circuit for mold clamping 5 mold clamping packing 6 piping for decompression 7 vacuum circuit for molding 9 sealing material 9a fitting groove 10 Upper mold 11 Engagement protrusion 12 Intake pipe 13 Inlet 14 Engagement recess 21 Intake hole 22 Vacuum suction chamber 23 Intake pipe 24 Clamping means 24a Insertion groove 24b Plug 31 Molding device main body 32 Mixing head 33 Raw material hose 34 Trap 35 Suction Piping 36 valves

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area B29L 9:00

Claims (4)

[Claims] 1. A method for molding fiber-reinforced plastic at the same time as
A method of integrating a surface layer material for beauty / protection, which replaces the conventional gel coat layer forming step with a surface layer material having a shape capable of being brought into close contact with the inner wall surface of a mold for molding a fiber reinforced plastic. Pre-made, a step of attaching this surface layer material to the inner wall surface of the molding die, a step of disposing a fibrous reinforcing material in the molding die, and sealing the molding die and injecting a plastic material, the surface layer A method of molding a fiber reinforced plastic having a surface layer material, the method including molding the material integrally with the material. 2. Simultaneously with the molding of fiber reinforced plastic,
A method for integrating a surface layer material for beauty and protection, which is a vacuum forming method for forming a fiber reinforced plastic, in which a sheet or thin plate surface layer material is vacuum-sucked and adsorbed on the inner wall surface of the forming die. Instead of the conventional gel coat layer forming step, a step of vacuum suctioning and attaching the surface layer material to the inner wall surface of the forming die is used, which has a function similar to that of a die, and fiber reinforcement in the forming die. A method of molding a fiber-reinforced plastic having a surface layer material, comprising: a step of disposing a material; and a step of sealing the molding die, injecting a plastic material, and molding the material integrally with the surface layer material. 3. A molding die main body A having a divided structure and a sheet or thin plate-shaped surface layer material B are vacuum-sucked to at least a part of an inner wall surface of the molding die body A so as to be attached thereto. Clamping means 24 for fixing the peripheral edge portion of the mold die to the die mating surface of the die body A or the inner wall surface of the die, and a portion of the die wall of the die body A to which the surface material B is attached. And a plurality of suction holes 21, and a vacuum suction chamber 22 assembled to the outer surface of the mold wall so as to cover the plurality of suction holes 21. Molding of a fiber reinforced plastic having a surface layer material. Type. 4. The mold fitting surface of the mold body A is provided with a mold clamping vacuum circuit 4 for clamping under atmospheric pressure, and a part of the mold wall is made of a flexible material. The fiber-reinforced plastic molding die having the surface layer material according to claim 3, wherein a part of the mold wall can be reversibly bulged and deformed by the injection pressure of the plastic material.