JPH0160082B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention solves the difficulty of secondary processing after molding, especially cutting and polishing, in the production of reinforced plastic helmets using high modulus fibers such as polyamide fibers as reinforcement materials. .

High modulus fibers are highly flexible and have excellent mechanical strength and impact resistance, so they have come to be widely used as reinforcing materials for reinforced plastics. The present inventors are currently developing a helmet using high-modulus fibers as a reinforcing material, but in the past it has been extremely difficult to perform secondary processing after molding the helmet, particularly cutting unnecessary parts around the helmet, deburring it, and polishing it afterwards. This is due to the characteristics of the high elastic fiber itself.

As a result of various studies to solve this difficulty in cutting the circumferential edge of a helmet, we decided to place relatively low-elastic fiber reinforcement around the circumferential edge of a helmet reinforced with high-modulus fibers, and to use thermosetting resin. It is possible to solve this difficulty by impregnating both of these fiber reinforcement materials and curing the thermosetting resin so that the high modulus fibers and low modulus fibers are integrally bonded and molding the helmet. Summer.

In the present invention, the two types of fiber reinforcing materials can be in any form such as woven fabric or nonwoven fabric. As the highly elastic fibers, polyamide fibers (aliphatic polyamide, aromatic polyamide), polyester fibers (particularly aromatic polyester), etc. are used. On the other hand, glass fibers are mainly used as relatively low elastic fibers.

The thermosetting resin may be an unsaturated polyester resin, an epoxy resin, a phenol resin, etc., and is not particularly limited. The thermosetting resin is impregnated into the fiber reinforcing material before or after the reinforcing material is placed in the mold. In the former case, it is preferable to bring the resin to the B stage by heating or at room temperature after resin impregnation. In the latter case,
After the reinforcing material is placed in the female mold of the mold, resin is injected into the mold to impregnate it.

An example of a method for molding the helmet of the present invention is as follows:
The case where polyamide fiber woven fabric and glass fiber nonwoven fabric are used will be explained.

A polyamide fiber woven fabric is cut into roughly the same shape, slightly smaller than the desired size of the helmet, and a predetermined number of sheets are laminated and placed in the center of the inner surface of the female mold 1 of a preheated helmet molding mold as shown in FIG. Place it. A predetermined number of glass fiber nonwoven fabrics 4 are laminated on the peripheral edge of the laminated polyamide fiber woven fabric 3 along the inner peripheral edge of the female mold 1, and then a predetermined amount of thermosetting resin 5, such as unsaturated polyester resin, is laminated. Inject (Figure 2). The male mold 2 of the molding mold is gradually installed and the mold is closed to impregnate both of the reinforcing materials with the thermosetting resin (Fig. 3), and the helmet is formed by heating and pressurizing for a predetermined period of time with the mold closed. to form. In this case, as shown in FIG. 5, the gap 7 between the sliding portions of the female die 1 and the male die 2 is made extremely small.

This prevents the resin from flowing out of the mold, and when the mold is closed, excess glass fiber nonwoven fabric around the area is crushed or cut by the molding pressure, making secondary processing of the molded helmet extremely easy. .

After opening the mold, the molded helmet 6 is taken out (FIG. 4), and the unnecessary parts 8 generated around it are cut off along the cut points 9 using scissors or the like. If a mold as shown in FIG. 5 is used, secondary processing such as cutting and polishing of unnecessary portions 8 is extremely easy since the glass fibers at the locations to be cut are crushed or cut as described above.

Finally, a finished helmet is obtained by performing post-processing such as polishing the cut portion, painting the surface, and attaching interior parts.

For comparison, when a helmet was molded only from polyamide fiber woven fabric without using glass fiber, it was not easy to cut off unnecessary parts around it after molding.
Special cutting methods, such as water jet cutters or gas lasers, must be used. Even in this case, the time required for cutting was at least about 15 minutes, and the cut surface remained with whisker-like fuzz of polyamide fibers, and the subsequent polishing process also required a great deal of labor and time.

In the method of the present invention, since the cutting area around the helmet is made of low elastic fibers such as glass fibers, secondary processing such as cutting and polishing is easy.

Therefore, there is no need for expensive equipment investment due to the use of a special cutting method, which greatly contributes to lowering the cost of the helmet.

The above-described method can also be used when molding a helmet by placing prepreg in which the high modulus fibers constituting the center portion of the helmet and the low modulus fibers constituting the peripheral portion are impregnated with a thermosetting resin in advance in a mold. Molding and secondary processing can be easily performed in exactly the same manner as in the example.

Note that the present invention also includes the use of fiber materials other than high-elastic fibers, such as glass fiber nonwoven fabric, as a reinforcing material for the outermost surface layer of the helmet in order to improve the appearance and coat the helmet.

As described above, the present invention provides a method for manufacturing a helmet that is easy to perform secondary processing such as cutting and polishing even though high-modulus fibers are used as a reinforcing material, and in which the toughness of high-modulus fibers is sufficiently exhibited. It is something to do.

[Brief explanation of drawings]

1 to 4 are diagrams showing an example of the molding process of the helmet of the present invention. FIG. 5 is an enlarged view of the main parts of the mold. 1: female type, 2: male type, 3: polyamide fiber woven fabric, 4: glass fiber nonwoven fabric, 5: thermosetting resin,
6: Molded helmet, 7: Gap between mold sliding parts,
8: Surrounding unnecessary area, 9: Cutting point.

Claims (1)

[Claims] 1. In a method for manufacturing a helmet made of fiber-reinforced plastic, a high-modulus fiber-reinforced material constituting the central portion of the helmet and a low-modulus fiber-reinforced material constituting the peripheral portion of the helmet are impregnated with a thermosetting resin, and A method for manufacturing a helmet, characterized in that the resin-impregnated reinforcing material is pressurized and cured to form a helmet, and the peripheral portion of the obtained helmet molded body made of the low-modulus fiber reinforcing material is subjected to secondary processing.