JPS58103477A - Water sliding board and production thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides hydroplaning boards, such as sailboards,
Concerning boards such as surfboards and methods of manufacturing them.

Conventionally, such boards were made by molding the upper skin, which makes up the deck surface, and the lower skin, which makes up the bottom surface, out of synthetic resin using a hand lay-up method, and then glued these skins together in a monaka style. It is then made by injecting a foaming polyurethane liquid into the cavity between the outer skins and causing it to foam. With this structure, peeling easily occurs at the bonded surfaces, and there are also problems in terms of strength.

An object of the present invention is to provide a hydroplane board that is free from peeling and has sufficient strength.

According to the invention, the board includes a skin of a rigid foam material (e.g. polyurethane) and a similar, single-layer body encased in this skin. The specific gravity includes a core made of a foamed material with low specific gravity. The skin is covered with a layer of reinforcing material, which is further covered with a layer of synthetic resin. Therefore, not only is there no problem of peeling, but the strength is also increased. Preferably, the reinforcement is glass fiber and the synthetic resin is polyester.

Another object of the invention is to provide a method for manufacturing a hydroplane board as described above.

According to the method of the present invention, the deck-side skin and the bottom-side skin are molded from a foamable synthetic material using two mold parts having cavities that correspond to their external shapes in an open, down position.

At this time, it is preferable to form the outer skin by spraying a liquid of this material onto the surface of each cavity to form a uniform layer and foaming. After that, these mold parts are combined to form a cavity between the foam skins, and the foam composite is applied there.
Inject the material and foam. The intermediate product thus produced is covered with a reinforcing material such as glass fiber, placed in an injection mold, and a synthetic resin that will form the outer surface of the board is injected to form a board in the desired shape.

The present invention will now be described with reference to the accompanying drawings.

Referring to FIG. 1, to make the hydroplaning board of the present invention, a skin is first formed using two separable mold sections. The mold part 1 shown on the left side of FIG.
On the other hand, the mold part 3 shown on the right side of FIG. 1 has an open cavity 4 that matches the outer shape of the outer skin part constituting the decking surface of the board. A foamable synthetic material, for example, a stock solution of foamable polyurethane having a specific gravity of about 046, is uniformly sprayed onto the surfaces of these open cavities 2 and 4, and foamed to form outer skins 5 and 6, respectively.

Next, as shown in FIG. 2, the foamed outer skins 5, 6- are placed in the open cavities 2, 4, and the mold parts 1 are assembled with the open cavities 2, 4 facing each other.

Match 3. . A sprue 7 is provided in the mold part 3 for the deck shell 6, and after mold alignment and mold clamping, the sprue is passed through from an injection nozzle 8 of an injection machine (not shown).
A material such as foamable polyurethane with a specific gravity of about 0.0.23 is injected into the cavity between the outer skins 5 and 6 and foamed to form the core. Let's call it part 10. In this way, a foamed intermediate product 11 is obtained (FIG. 3) consisting of two combined outer skin parts 5, 6 and a core part 10 between them.

Next, a reinforcing material layer 12 is formed on the outer peripheral surface of this intermediate product 11, as shown in FIG.

This layer 12 can be formed, for example, by applying glass fiber threads all over the surface of the intermediate product 11.

The intermediate product 11 covered with glass fiber in this way is then
As shown in FIG. 5, it is installed in the mold cavity 15 of the injection mold 14, leaving a predetermined gap 16 around the periphery. Next, a synthetic resin, for example polyester, forming the outer surface of the board is injected into the mold cavity 14 from an injection molding nozzle 19 through a sprue 18 at a weight of, for example, about 7 kg/as2.
The synthetic resin layer is formed around the intermediate product. The synthetic resin uniformly impregnates the glass fiber layer 12 and fixes it. When taken out after curing, as shown in FIG. 6, there is a foam 10 with a relatively low specific gravity in the innermost part, surrounded by foam skins 5 and 6 with a higher specific gravity, and then It is possible to obtain a new hydroplane board which has a glass fiber layer 12 impregnated with synthetic resin and has a synthetic resin surface layer 20 on the outermost side, which is free from peeling and has improved strength.

If the outer skin is formed by spraying and foaming a foamable material on the surface of the open cavity, the surface density of the outer skin will be very high and hard, so in the final process, synthetic resin is injection molded. Inclusion of r+ into the foam shell
t is small, and the board body weight can be reduced. Furthermore, for the same reason, the fluidity of the synthetic resin on the surface of the outer skin is improved, so dents and the like do not occur and variations in quality are eliminated.

[Brief explanation of drawings]

Figure 1 is a diagram showing the outer skin being molded using a mold part that can be used when carrying out the method of the present invention, and Figure 2 is a diagram showing the mold parts in Figure 1 being combined to form a foam core part. Fig. 3 is a sectional view showing the intermediate product produced in this way, and Fig. 4 is a cross-sectional view showing the intermediate product of Fig. 3 with a reinforcing material layer formed. Figure 5 is a diagram similar to Figure 3, Figure 5 is a diagram showing the stage of injection molding the outer surface of the board around the intermediate product in Figure 4, Figure 6 is an enlarged view of the circular part of Figure 5. Yes. 5.6...Outer skin lO...Core 12...Glass fiber layer 20...Synthetic resin layer Attorney Akira Kawano

Claims (1)

[Scope of Claims] (1) - An outer skin portion made of a hard foam material that constitutes the deck surface and bottom surface, a core portion made of a foam material with a smaller specific gravity and surrounded by the outer skin, and a core portion of the outer skin portion made of a foam material with a lower specific gravity. A hydroplaning board comprising a reinforcing material layer on the outer surface and a synthetic resin layer covering the reinforcing material layer. (2. A hydroplane board according to claim 1, characterized in that the foam material forming the outer skin portion and the core portion is foamed polyurethane. (3) Claims A hydroplane board according to claim 1, wherein the reinforcing material layer is made of glass fiber. (4) The method according to claim 1, wherein the synthetic resin A hydroplane board characterized in that the layer is made of polyester. (5) A method for producing a hydroplane board having a deck surface and a bottom surface, the upper skin forming the deck surface and the lower skin forming the bottom surface. The side skins are formed from a synthetic material of relatively low specific gravity using two open mold parts with open cavities that match the shape of their respective external surfaces, and these skins are inserted after foaming and curing. The mold parts are placed together with their cavities facing each other to form a space between the outer skins, and after the mold is closed, a foamable synthetic material having a specific gravity smaller than that of the foamable synthetic material is filled in the space. injecting and foaming to form an intermediate product consisting of upper and lower skins and a foam sandwiched between them, and after removing this intermediate product from the fan, forming a layer of reinforcing material on its outer circumferential surface; A method characterized by placing this in an injection mold and injecting a synthetic resin to form the outer surface of the board to mold a board having a desired external shape. (6) Claim No. In the method described in item 5, the step of forming the upper and lower outer skins in the respective mold parts includes spraying a foamable synthetic material liquid to a uniform thickness on the cavity surface of each mold;
A method comprising the step of foaming.