JPH0284973A - Manufacture of golf shaft - Google Patents

Abstract

PURPOSE:To easily manufacture a smooth shaft to have a linear pattern on a surface by covering a plastic-made shaft main body with a knit-shaped body, for which a fiber bundle is knitted in a cylinder shape, further covering the knit-shaped body with a prepreg sheet to include glass fiber and setting the prepreg. CONSTITUTION:At first, a shaft main body S before or after the thermosetting of the prepreg is inserted through a knit-shaped body 4 which is knitted in the cylinder shape. For the knit-shaped body 4, for example, high strength fiber such as aramid fiber etc., or a cotton or silk thread, etc., is knitted in the cylinder shape and the knit-shaped body is composed of one type or the different two or more types of the fiber bundle. Since the fiber bundle of two or more types is knitted, the multi-color linear pattern can be formed. After this knit-shaped body 4 is wound, the prepreg sheet to include the glass fiber is wound and a transparent layer 5 is provided. This transparent layer 5 covers unevenness, which is generated by the covering of the knit-shaped body 4, and makes the surface of the shaft 5 smooth. Then, as the resin of the prepreg to be the base material of the transparent layer 5, epoxy resin or unsaturated polyester resin is used. After that, a pressing tape is arbitrarily wound and the resin is set. Then, the shaft is obtained.

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention relates to a method for manufacturing a golf shaft, and more particularly, to a golf shaft having a line pattern on the surface of the shaft (prior art). Shafts made of plastic are common, but
Such shafts usually have the color of the material themselves, and are not provided with various colors or patterns. That is, steel shafts generally have a metallic color, and carbon shafts generally have a black color.

However, in recent years, as the number of female golfers has increased, golf shafts of various colors have been developed and put on the market.

Golf shafts with a color different from the color of the material itself are generally golf shafts made of plastic, and are colored by painting the surface of the shaft or adding pigments to the resin that makes up the shaft. Ta.

However, when applying color to the shaft by painting, for example, there is a risk that the paint will peel off over a long period of use, making the design undesirable, and in the case of shafts containing pigments, the plastic layer may become brittle.

Furthermore, with the above-mentioned coloring methods such as painting or adding pigments, it is difficult to achieve anything other than simple coloring, and it is virtually impossible to create a pattern on the shaft. was there.

(Object of the Invention) The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a method for manufacturing a golf shaft provided with a line pattern.

(Outline of the invention) In order to achieve the above object, the golf according to the present invention is characterized in that the knitted body is further covered with a prepreg sheet containing glass fiber, and the prepreg is cured.

According to the present invention, the shaft body is covered with a braided body made of fiber bundles knitted into a cylindrical shape, and is further covered with a transparent glass fiber reinforced resin layer, so that the pattern of the braided body can be visually recognized through the transparent resin layer. Therefore, there is an advantage that a shaft having a mesh pattern on the shaft surface can be easily manufactured.

(Example) FIG. 1 is a partial perspective view of an example of a typical plastic golf shaft. A prepreg sheet arranged in the shaft is wound to form a torsion prevention layer 2, and a prepreg sheet with reinforcing fibers aligned in the axial direction of the shaft is wound around this torsion prevention layer 2 to form a rigidity retaining layer 3. After thermosetting the aforementioned prepreg sheet, a surface layer (
(not shown) was optionally provided.

In the manufacturing method as described above, according to the present invention, the second
As shown in the figure, the shaft main body S of the prepreg before or after thermosetting is inserted into a cylindrical knitted body 4.

Although such a knitted body 4 is not fundamentally limited in the present invention, it may be made of, for example, aramid fiber, tyranno fiber,
In addition, it may be a cylindrical knitted body made of ceramic fibers, high-strength fibers such as polyethylene fibers (for example, Techmilon R manufactured by Mitsui Petrochemicals), cotton, silk thread, or the like. It is clear that the fiber bundles constituting the above-mentioned knitted body can be one type of the above-mentioned fiber bundles, or can be two or more different types of fiber bundles. By knitting two or more types of fiber bundles in this way, a multicolored line pattern can be formed, and the knitted body used in the present invention can be easily manufactured as described below.

In particular, when a high-strength fiber bundle is used as the fiber bundle constituting the knitted body 4, an effect of preventing twisting of the shaft is also produced, so that there is also an advantage that, for example, the anti-twisting layer 2 can be made thinner.

The apparent number of lines in the length direction of the shaft S of such a knitted body 4 (the number of lines visible from the surface of the manufactured shaft) is preferably 0.5 to 3 lines/10 mm.

If the number is less than 0.5 fibers/10 mm, the line pattern will become rough and undesirable in terms of design, and even if high-strength fibers are used as visible fibers, it will be difficult to exhibit the twist prevention effect. This is because if it exceeds 10 mm, the line pattern becomes too fine, which is also undesirable in terms of design. Similarly, the number of fiber bundles in the circumferential direction is preferably 4 to 16. This is because if it deviates from the above range, the twist prevention effect may not be exhibited or the design may become undesirable.

The thickness of the visible fiber bundle as described above is preferably 5
It is preferably 0 to 600 deniers. If it is less than 50 denier, the line pattern will be less visible than the shaft surface;
This is because if it is thicker than 0.00 denier, the braided body 4 will be thick, resulting in the golf shaft being thicker and heavier.

It is desirable to knit the knitted body 4 with the number of visible fiber bundles as described above into a cylindrical shape, but if the number of fiber bundles is too small, it will be difficult to manufacture the above-mentioned knitted body. . Therefore, it is possible to weave fiber bundles that cannot be visually recognized through the transparent layer 5, such as glass fiber bundles, so that the apparent number of fibers falls within the above-mentioned range. By making 2/3 of the visible fiber bundles glass fibers, the apparent number of fibers is 16 in the entire circumferential direction.
It is possible to manufacture a knitted body 4 with 2.2 pieces/10 mm in the length direction, and by making 11/12 glass fibers, for example, an apparent knitted body 4 with 8 pieces in the circumferential direction and 1.1 pieces/10 mm in the length direction can be produced. body 4 can be manufactured.

In other words, fibers that are visible from the surface of the manufactured shaft,
By manufacturing a knitted body by knitting fibers (such as glass fibers) that cannot be visually recognized from the surface after manufacture, a knitted body with a small apparent number of fibers can be easily manufactured.

After winding the knitted body 4 in this manner, a prepreg sheet containing glass fiber is wound to provide a transparent layer 5. This transparent layer 5 covers the unevenness caused by covering the above-mentioned knitted body 4 and smoothes the surface of the shaft S.

The resin of the prepreg that becomes the base material of the transparent layer 5 is as follows:
In the present invention, basically any transparent material can be used. For example, it can be an epoxy resin, an unsaturated polyester resin, a phenolic resin, a vinyl ester resin, etc.

The amount of glass fiber contained in such a prepreg is preferably 100 to 250 parts by volume per 100 parts by volume of the resin. If the amount is less than 100 parts by volume, the strength of the transparent layer 5 may not be sufficient, while if it exceeds 250 parts by volume, the glass fibers may impede the transparency of the transparent layer 5.
This is because it becomes undesirable in terms of design. Further, the thickness of the added glass fiber is preferably 200 to 1000 deniers. If it is less than 200 denier,
The reinforcing effect of the transparent layer 5 cannot be expected much, and the -1000
This is because if the denier is exceeded, the transparent layer 5 becomes opaque, and there is a risk that a slight cloudiness may be formed.

The thickness of this prepreg, that is, the thickness of the transparent layer 5 is preferably 100 to 300 μm. 100μm
If it is less than 300 μm, the unevenness caused by the knitted body 4 will not be smooth, and if it exceeds 300 μm, it will give a sense of opacity.

After winding the prepreg containing glass fibers onto the knitted body 4 in this manner, a pressure tape is optionally wrapped around the prepreg, and the resin is cured to form a shaft.

At this time, when a presser tape is used, the presser tape becomes uneven, so the surface is polished and optionally coated with a transparent decorative layer to prepare the product.

(Effects of the Invention) As explained above, according to the golf shaft manufacturing method according to the present invention, the surface of the conventional shaft is covered with a braided body and a transparent layer containing glass fiber is provided, so that a line pattern is formed on the surface. There is an advantage that a smooth shaft having a smooth shaft can be easily manufactured.

[Brief explanation of the drawing]

Figure 1 is a partial perspective view showing the configuration of the golf shaft, Figure 2 is a partial perspective view showing the configuration of the golf shaft.
The figure is a partial perspective view of one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Core metal, 2... Torsion prevention layer, 3... Rigidity maintenance layer, 4... Knitted body, 5... Transparent layer.

Claims (2)

[Claims] (1) A plastic shaft body is covered with a braided body made of cylindrical fiber bundles, and the braided body is further covered with a prepreg sheet containing glass fiber, and the prepreg is cured. A method for manufacturing a golf shaft. (2) The method for manufacturing a golf shaft according to claim 1, wherein the knitted body is manufactured by knitting fibers that are visible from the surface of the manufactured shaft and fibers that are not visible from the surface of the manufactured shaft.