JPH04144716A - Manufacture of synthetic-resin molded form - Google Patents

Abstract

PURPOSE:To prevent the adhesion of sheets for both molding positively by interposing a spacer obviating the adhesion of these sheets for both molding between the sheets for both molding when the sheets for both molding are disposed between molding dies. CONSTITUTION:Two sheets 91, 92 for molding made of a thermo-setting synthetic resin under an uncured state are disposed between molding dies 131, 132 the molding dies 131, 132 are closed and the peripheral sections of the sheets 91, 92 for molding are held, and one molding surface sheet 91 is contact-bonded with the molding surface 141 of the first molding die 131 and a first shell 31 is molded and the other sheet 92 for molding is contact-bonded with the molding surface 142 of the second molding die 132 and a second shell 32 is molded respectively. Both shells 31, 32 are heated and thermoset by the molding dies 131, 132 while these peripheral sections are joined mutually. When the sheets 91, 92 for molding are arranged between the molding dies 131, 132, a spacer 6 preventing the adhesion of these sheets 91, 92 is interposed between the sheets 91, 92 for molding.

Description

Detailed Description of the Invention A1 Object of the Invention (13 Industrial Fields of Application) The present invention relates to a method for manufacturing a synthetic resin molded article, and in particular, to a method for manufacturing a synthetic resin molded article, in which first and second molds with molding surfaces facing each other are opened, and a pre-molding process is performed. a step of arranging two uncured thermosetting synthetic resin molding sheets between the molds; a step of closing both molds and sandwiching the peripheral edges of both molding sheets between the molds; Pressing one of the molding sheets onto the molding surface of the first mold
a step of press-bonding the shell and the other molding sheet to the molding surface of the second mold to mold a second shell, respectively, and heating and thermosetting both shells with both molds and curing their peripheral edges; The present invention relates to an improvement in a method for manufacturing a synthetic resin molded product in which the steps of joining parts are sequentially performed.

This type of manufacturing method was developed by the present inventors, and is more economical than the case of manufacturing a synthetic resin molded product by joining separately molded first and second shells, and is It is effective in reducing the manufacturing cost of products.

(2) Prior art When disposing a molding sheet between the preceding molds, the inventors adopted a method of spraying a lubricant on the opposing surfaces of the two molding sheets in order to prevent them from coming into close contact with each other. Was.

(3) Problems to be Solved by the Invention However, if the lubricant is sprayed as described above, the two molding sheets may stick together due to their increased tackiness due to preheating. There was a problem in that the molding sheet could not be pressure-bonded to each molding surface, resulting in molding defects.

In view of the above, an object of the present invention is to provide the above-mentioned manufacturing method that can reliably prevent the two molding sheets from coming into close contact with each other.

B0 Structure of the Invention (1) Means for Solving the Problems The present invention involves opening first and second molds with their molding surfaces facing each other, and inserting two uncured thermosetting sheets between the front molds. a step of arranging a synthetic resin molding sheet; a step of closing both molds and sandwiching the peripheral edges of both molding sheets between the molds; and placing one of the molding sheets in the first mold. a step of press-bonding the molding sheet to a molding surface to form a first shell, and pressing the other molding sheet to the molding surface of the second mold to mold a second shell, and heating both shells with both molds. A method for manufacturing a synthetic resin molded product, which sequentially performs the steps of thermally curing the molded product and joining the peripheral edges thereof. A feature is that a spacer is interposed between them to prevent them from coming into close contact with each other.

(2) Effect By using the spacer as described above, it is possible to reliably prevent the two molding sheets from coming into close contact with each other.

(3) Example 1. FIG. 2 shows a fiber-reinforced synthetic resin molded product 1, which includes first and second dish-shaped shells 3, . 3□, a foam 5 filled between the opposing main bodies 48.4□ of both shells 31.3□, and a cage-shaped spacer 6 embedded within the foam 5. Each shell 31 . It was formed during manufacturing.

FIG. 3 shows a molding sheet 9 used to obtain the molded product 1, and the molding sheet 9 includes a flexible film 10.
A synthetic resin liquid layer 11 and an uncured base material layer 12 are sequentially laminated on one surface of the substrate.

The flexible film 10 is made of flexible thermoplastic synthetic resin such as vinylon, polyvinyl alcohol, nylon, etc.
It functions as a support for the uncured base material layer 12 and the synthetic resin liquid layer 11, and is peeled off from the molded article 1 after molding.

The uncured base material layer 12 is composed of a reinforcing fiber aggregate and a synthetic resin liquid impregnated into the aggregate.

Examples of reinforcing fibers include glass, carbon, metal, and Kevlar (
Various types of fibers are used, including (trade name, aramid resin), Tetron (trade name, polyester resin), etc., and as synthetic resin liquids, unsaturated polyester resin, epoxy resin,
Thermosetting synthetic resin liquids such as unsaturated polyurethane resins and epoxy (meth)acrylate resins are used.

The synthetic resin liquid layer 11 is cured during the curing process of the uncured base material layer 12 to form the surface layer 8 of the molded product 1, and is mainly composed of the thermosetting synthetic resin liquid, and contains pigments and crosslinked resin. agent,
It is prepared by adding a curing catalyst, etc.

Here, the synthetic resin liquid means a synthetic resin that has high viscosity at room temperature, but has the property of deforming or flowing during the preheating or pressing stage of the molding sheet 9, and is liquid at room temperature. , that doesn't mean.

Next, an example of manufacturing the molding sheet 9 will be described.

Product name: Borac N-325) Silicic acid anhydride powder: 2 parts by weight Titanium dioxide pigment: 10 parts by weight Styrene (crosslinking agent)
Then, 1.5 parts by weight of magnesium oxide and 1 part by weight of t-butylperoxy-2-ethylhexano were added to 100 parts by weight of the mixed solution. A synthetic resin liquid was prepared by adding ate (curing catalyst).

This synthetic resin liquid was applied to one side of a flexible film 10 made of vinylon with a thickness of 50 μm to a thickness of 1 to 211II11, and then the applied layer was subjected to a thickening treatment at 40°C for 13 hours to form a synthetic resin liquid layer. 11 was formed.

1 part by weight of L-butylperoxy-2-ethylhexanoate was added to 100 parts by weight of an unsaturated polyester resin (manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd., trade name Borac C, -105) to synthesize an uncured base material layer. A resin liquid was prepared. In addition, a reinforcing fiber aggregate was prepared by overlapping three glass fiber cloths (manufactured by Nittobo Co., Ltd., trade name C-450A). This aggregate is impregnated with the synthetic resin liquid layer 11.
An uncured base material layer 12 having a thickness of 2 to 3 m was formed by laminating on the upper surface of the laminate, and then the laminate was subjected to a defoaming treatment to obtain a molding sheet 9 having a thickness of about 4 mm.

FIG. 4 shows a method for manufacturing the molded product 1.

The manufacturing apparatus used in this manufacturing method is configured as follows. That is, in FIG. 4(a), the fixed first mold 1
3. A second mold 13□ is disposed above the mold so that it can be raised and lowered. The image forming molds 13+ and 13z have concave forming surfaces 14 facing each other.
．． ．． 142, and a plurality of exhaust holes 15.142 on each molding surface 141.142. ．． 152 is open. Also number 1. Molding surface 14 of second mold 13°13. ．． 142 surrounding the upper and lower end surfaces 16. ．． Concave portions i7+ and i7□ are formed in 16□ to face each other.

In manufacturing the molded product 1, the following steps are performed in sequence. In this case, the temperature of the drawing mold 13113□ was set at 120°C.

(1) As shown in FIG. 4(a), the second mold 132
Raise both molds 131, 13! Open and place two preheated molding sheets 9°9 between them! A cage-shaped spacer 6 made of a metal wire such as a reinforcing bar was also provided. That is,
As shown in FIG. 4A, the lower molding sheet 91 is
The first mold 13 is made with the flexible film 10 facing downward.
1 so as to cover the molding surface 14 of the molding surface 16. Then, the dragon-shaped spacer 6 is placed on the lower molding sheet 9I, and then the upper molding sheet 93 is placed on the cage-shaped spacer 6 with its flexible film 10 facing upward.

At that time, the recesses 171 and 17 on the upper and lower end surfaces 16+ and 162
□) 9. ．． The gate member 18 is sandwiched between the gate members 92.

The gate member 18 is connected to a supply source 19 for liquid synthetic resin unfoamed material.

If the cage-shaped spacer 6 is interposed between the image forming sheets 91' and 9z as described above, it is possible to prevent the sheets 9° and 9t from coming into close contact with each other.

(11) As shown in FIG. 4(b), the second mold 1
32 is lowered to close both molds 131.13□, and both molding sheets 9.
．． The peripheral edge of 92 was sandwiched. As a result, the upper and lower end surfaces 16
．． ．． 16! In between are both molding sheets 9, . 9. The gate member 18 is also sealed through the upper and lower end surfaces 16 . ．． 16
! held between.

(ii) As shown in FIG. 4(C), the supply source 19 is activated, and the remolding sheet 93,
Liquid synthetic resin unfoamed material 20 was injected between 9z and 9z.

(iv) As shown in Figure 4 (b), the unfoamed body 2
0 is foamed, and the foaming pressure causes the lower molding sheet 9I to be molded into the first mold 13. Molding surface 14. Crimp the first
Shield 3. The upper molding sheet 92 is pressed onto the molding surface 142 of the second mold 132 to form the second shell 3.
z was molded respectively. In this case, since the spacer 6 has a cage shape, the foaming pressure is allowed to propagate to both molding sheets 91.9g.

Next, both shells L and 3g are heated and thermosetted using both molds 13° and 13mm, and they are joined via the foam 5, and their peripheral portions, and therefore the uncured base material layers 12, are bonded together. Molded product 1 was obtained by joining.

(v) The molded product 1 was released from the mold, the flexible film 10 was peeled off from the surface layer 8, and the gate member 18 was removed.

By removing the gate member 18, a cylindrical portion 2a is formed between the flange portions 21 and 28. Also, both flange portions 23, 2
! In this case, the uncured base material layer 12 of both shells 33, 32
As the two are fused together, a large bonding force can be obtained. Further, since the cage-shaped spacer 6 made of a metal wire such as a reinforcing bar functions as a reinforcing material, the strength of the synthetic resin molded product 10 can be significantly improved.

In the present invention, it is also possible to use fluid pressure such as compressed air or compressed liquid instead of the foaming pressure.

The present invention is effective, for example, in manufacturing fiber-reinforced synthetic resin fan blades.

Conventionally, in manufacturing this type of fan blade, a pair of shells that will serve as the outer skin material are formed into one piece using the hand lay-up method, a reinforcing core material is bonded to one of the shells after curing with an adhesive, and curing is performed. Various processes such as bonding the other shell to the reinforcing core material with adhesive, simultaneously bonding the peripheral edges of both shells with adhesive, and injecting unfoamed liquid synthetic resin between both shells to foam them. However, there is a problem in that the manufacturing process for fan blades is complicated and the productivity is poor.

According to the present invention, by molding both shells, joining them to the reinforcing core material, joining the peripheral edges of both shells, and injecting and foaming the unfoamed material in the same mold, the fan blade It is possible to simplify the manufacturing process and improve productivity.

Furthermore, since both shells in an uncured state are joined together when they are cured, a greater joining force can be obtained than in the conventional case where shells are joined after being cured.

C0 Effects of the Invention According to the present invention, by employing an extremely simple means such as using a spacer, a sound synthetic resin molded product can be obtained by preventing the image forming sheet from coming into close contact with each other.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of a molded product, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, FIG. 3 is an enlarged sectional view of a molding sheet, and FIG. 4 (a) to (d) are explanatory diagrams of the manufacturing process, and FIG. 4A is an explanatory diagram showing the orientation of two molding sheets. 1...Synthetic resin molded product, 3I, 3t...1st. Second
Shell, 6...Cage-shaped spacer, 9.91.92...
Sheet for molding, 13. ．． 13g...1st. Second mold, i4+, i4z...molding surface, 20...liquid synthetic resin unfoamed material

Claims (3)

[Claims] (1) The first molding surface (14_1, 14_2) facing each other
and a step of opening the second mold (13_1, 13_2) and disposing two uncured thermosetting synthetic resin molding sheets (9_1, 9_2) between both molds (13_1, 13_2). and a step of closing both molds (13_1, 13_2) and sandwiching the peripheral edges of both molding sheets (9_1, 9_2) between the molds (13_1, 13_2), and one of the molding sheets (9_1). to the molding surface (14_1) of the first mold (13_1) to form the first shell (3_1), and the other molding sheet (9_2).
) on the molding surface (14_2) of the second mold (13_2)
The process of molding the second shell (3_2) by pressing the two shells (3_1, 3_2) into the molds (13_2)
1, 13_2), and the steps of heating and thermosetting them and joining their peripheral parts to each other are sequentially performed.
_2) When disposing both molding sheets (9_1, 9_2) between them, a spacer (6) is interposed between both molding sheets (9_1, 9_2) to prevent them from coming into close contact. Method for manufacturing synthetic resin molded products. (2) When pressing each molding sheet (9_1, 9_2) onto each molding surface (14_1, 14_2), fluid pressure is applied between both molding sheets (9_1, 9_2), and the spacer (6) The method for manufacturing a synthetic resin molded article according to item (1), wherein the synthetic resin molded article is formed into a cage shape to allow propagation of the fluid pressure. (3) The method for manufacturing a synthetic resin molded article according to item (2), wherein the fluid pressure is the foaming pressure of the unfoamed synthetic resin body (20).