JPH04112014A - Production of resin hollow molded form - Google Patents

Abstract

PURPOSE:To obtain a fiber-reinforced resin molded form which has an enough rigidity, can be made lightweight and has a hollow structure by pinching a balloon made of heat resistant resin between the stamping material made of glass fiber for reinforcement which is impregnated with thermoplastic resin, heating and setting the stamping material in a mold and molding the same while blowing compressed air into the balloon. CONSTITUTION:Thermoplastic resin reinforced with a glass mat of continuous fibers is utilized as the molding material. A balloon 1 made of heat resistant resin such as silicon resin is set between the stamping materials 2, 2 made of continuous glass fibers which are impregnated with e.g. polyprolylene resin and formed into a mat shape. The stamping materials are heated by a far-infrared ray heater 3 and placed on a bottom force 4 with a cavity 4a formed therein. A top force 5 is set and mold clamping is performed. The stamping materials are molded while blowing air into the balloon 1 through an air supply pipe 6. A hollow part 8 is formed in the central part of a molded form 7 by the balloon 1. The upper and lower stamping materials 2 are melt-bonded at the peripheries into an integral structure. When the mold is opened and the air supply pipe 6 is taken off from the molded form 7, the molded form having a hollow structure is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing a resin hollow molded product, particularly a fiber III' reinforced resin hollow molded product.

(Prior Art) Recently, FRP (glass fiber reinforced thermosetting resin) products have come to be used for various molded products such as automobile outer panels. For example, in the case of an engine foot, molding of such a fiber-reinforced resin molded product is carried out by inserting a foam material or the like as a core material into the molded product in order to ensure the rigidity and strength of the molded product. It's there. In this way, the compression molding method of fiber reinforced resin using 51@ material is disclosed in JP-A No. 63-246214f.
It has been proposed in the following publication. As shown in Figure 2, this is a sheet-like member made by impregnating a reinforcing mat of glass fiber 1 with thermoplastic resin! A filler material 15 such as a foamed material is placed between the members 14 having recesses formed therein using a material similar to the above material, and the filler materials 15 are placed in the cavities of the molds 11 and 12 and press-molded.

In addition to the above-mentioned engine hood, fiber-reinforced resin molded products are attracting attention because they can be widely used in automobile bodies, chassis, frames, etc. to reduce vehicle weight and improve fuel efficiency.

(Problem to be solved by the invention) In order to ensure the rigidity of a fiber-reinforced resin molded product and reduce its weight, it is best to use a hollow structure, but as shown in Table 1, conventional construction methods However, it was impossible to create hollow structures in fiber-reinforced resin molded products.

The present invention aims to provide an intelligent method for producing fiber-reinforced resin molded products that has a rigidity comparable to that of conventional steel plates without using fillers such as foam materials, and can be made lighter due to its hollow structure. The target is

(One step and action of Utanu to solve the problem) Uninvented is 1 reinforced gravity → Stamp pin made of fiber impregnated with thermosetting resin.
This is a method for producing resin hollow molded products, in which a balloon of liF# mature resin is sandwiched between 7 materials, heated, set in a mold, and pressurized air is blown into the balloon.

The molded product has a hollow part formed in the center thereof, and the stamping material is melted around the hollow part to form an integral structure, thereby obtaining a fiber-reinforced resin molded product having a hollow structure.

(Example) Embodiments of the present invention will be described with reference to the drawings.

The molding method of the present invention is based on the conventional stamping method, and the molding material used is a thermoplastic resin reinforced with a continuous fiber glass mat.

Figure 1 shows the molding process. First, as shown in Figure 1 (A), polypropylene (PP) is applied to continuous glass fibers.
Stamping material impregnated with resin and made into matte shape 2.2
In between, there are 2 balloons made of #mature resin like silicone resin.
To se-nod.

In the 18th H'n 18), I added the infrared heating machine 3 to the 420 Jf and installed the gear hitter r4a as shown in form ρ
Doya I4 can cut it. The temperature of the mold should be 25 to 70"C. As shown in No. 11-4 (D), set 55 and tighten the mold 1, and supply air to the balloon 1 through the air pipe 6. Blow and shape. Air pressure is 6 to 7 Kg/cm".

A hollow part 8 is formed in the center of the molded product 7 by a balloon l, and the stamping material 2 under L is fused around the hollow part 8 to form an integral structure. When the mold is opened and the air pipe 6 is removed from the molded product 7, a molded product with a hollow structure is obtained.

In addition to the above-mentioned vonopropylene (PP) resin, the matrix resins to be impregnated into the Mbe glass fibers include polyethylene terephthalate (PBTP), polyethylene terephthalate (PETP), polyamide (PA), polycarbonate (PC), polycenenylene ether fPPE, etc. ) and other thermoplastic resins such as PC/PBTP alloys, polyphenyleneoxycyto, /polyamyl CPP0/'P, A) Alloy Kasakasa]■.

Further, the balloon material may be a heat-resistant resin such as fluorocarbon resin or nylon resin.

Table 2 shows examples of molding materials and molding conditions.

Table 1 Table [Effects of the invention] 7 (The invention is a fiber-reinforced tree with a hollow structure that secures the rigidity of conventional steel J & curtains and is 11 ft# lighter!■ Molded products can be easily obtained There is an effect.

[Brief explanation of drawings]

FIGS. 1(A) to 1D) are explanatory diagrams of the molding process of the present invention, and FIG. 2 is a 4ζ cross-sectional view of the conventional molding method. 1: Balloon 2 Stamping material 3: Far infrared heating machine 4 Lower mold 5: E type 6: Air pipe 7/molded product 8: Hollow part Figure 1 Figure 2 Procedural amendment (voluntary) Monari 2w1o month

Claims (1)

[Claims] Heat-resistant resin balloons are sandwiched between stamping materials made of reinforcing glass fibers impregnated with thermosetting resin, heated, and then set in a mold and molded while blowing pressurized air into the balloons. A manufacturing method for resin hollow molded products characterized by: