JPS63163071A - Ring seal - Google Patents

Abstract

PURPOSE:To easily manufacture a ring seal, by linking non-bridged thermo- plastic fluorine-contained resin by irradiating radial rays. CONSTITUTION:A ring seal is formed by solid-state main unit part 1 of circular section and a coating layer 3 consisting of fluorine-contained resin with which a surface 2 of the main unit part 1 is coated. Here the main unit part 1 is formed by bridged thermo-plastic resin, and its component is a copolymer of TFE or the like. As the fluorine-contained resin, FEP, PFA, etc., are used. In manufacture, a wire rod material 1a, consisting of non-bridged thermo-plastic fluorine rubber, is formed being inserted into a tube unit 3a, consisting of fluorine-contained resin, and cut into a predetermined length. Forming the wire rod material into a ring shape and irradiating radial rays after both end surfaces 7 are welded, the non-bridged thermo-plastic fluorine resin rubber is linked. In this way, the ring seal is excellent in close seal quality facilitating even the manufacture with no generation of non-melted seam.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ring seal, and more particularly to a composite ring seal used in equipment installed in semiconductor manufacturing plants and the like that require extremely lean performance.

[Conventional technology and its problems]

Conventional ring seals of this type consist of a main body made of silicone rubber or fluorocarbon rubber, and a coating layer made of fluororesin that covers the outer surface of the main body. Alternatively, a main body made of fluororubber or the like is manufactured in a circular ring shape, and then a circular ring-shaped fluororesin coated half body having a half-circular cross section is covered from the top and bottom of the main body, and fused together. or (1) inserting a linear body of vulcanized rubber into a fluororesin tube and cutting it to a predetermined length to form a sizing body, and then forming the sizing body into a ring. There is a method of manufacturing by bending it into a shape and then fusing and integrating it.

However, in the above-mentioned method (2), the circular ring-shaped main body and the circular ring-shaped half body having a half-circular cross section must be manufactured separately, and then they must be made into a rod-shape. However, the manufacturing process is troublesome and the cost is high. In addition, in method (2), unfused joints were formed in the vulcanized rubber, the joints buckled, and the sealing performance deteriorated.

Therefore, in the present invention, by solving the above-mentioned conventional problems,
It is an object of the present invention to provide a ring seal that can be easily and quickly manufactured, contributes to cost reduction, and has excellent sealing performance.

[Means for solving problems]

In the ring seal of the present invention, a solid main body made of uncrosslinked thermoplastic fluororesin is inserted into a fluororesin type tube body, and both end faces of the solid body are fused to form a ring shape. The main body portion, which is a thermoplastic fluororesin, is crosslinked by radiation irradiation.

[Effect]

With the configuration as described above, there will be no unfused seams such as vulcanized rubber in the main body. In addition, there is no need to form a circular ring-shaped half body having a half-circular cross section, which facilitates its manufacture.

〔Example〕

Hereinafter, the present invention will be explained in detail based on drawings showing examples.

FIG. 1 shows an enlarged cross-sectional view of a ring seal according to the present invention. It consists of and. Further, the main body portion 1 is made of a crosslinked thermoplastic resin, and its components are copolymers of TFE, vinylicline fluoride, propylene hexafluoride, and the like. Furthermore, as fluororesins, FEP, PFA, ETFE, P
VF, PVF2, etc.

Next, a method for manufacturing such a ring seal will be explained.

As shown in FIG. 2, first, an elongated filament body 1a with a circular cross section is formed by extrusion molding or the like, made of uncrosslinked thermoplastic fluororubber, and then made of a fluororesin as described above. As shown in FIG. 3, the linear body 1a is inserted into the tube body 3a and cut to a predetermined length to form a sizing body 4. Then, as shown in FIG. 4, this sizing body 4 is bent as shown by the arrow to form a ring shape, and the ring-shaped sizing body 4 is molded into upper and lower molds as shown in FIG. The ring body 4 is heated and pressurized using a mold device equipped with 6.5 to fuse both end surfaces 7, 7 of the sizing body 4 to each other as shown in FIG.
Let it be a. That is, in this case, the lower half of the sizing body 4 is fitted into the ring-shaped groove provided on the upper surface of the lower mold 5, and the upper and lower molds 6.5 are brought close to each other to form the upper mold. The upper half of the sizing body 4 is fitted into a ring-shaped groove provided on the lower surface of the 6, and heated and pressurized to form an integrated ring body 4a.
shall be.

After cooling the upper and lower molds 6.5, the integrated ring body 4a is taken out and exposed to a radiation irradiation device (not shown).
As shown in FIG. 6, the ring body 4a is irradiated with radiation,
The striated body 1a (
In other words, the main body portion 1) is crosslinked.

Therefore, as shown in FIG. 1, a ring seal can be formed in which a solid body portion 1 with a circular cross section is covered with a tube body 3a (that is, a coating layer 3) made of fluororesin.

Further, the extrusion temperature when extrusion molding the above-mentioned filamentous body 1a is preferably about 170°C to 280°C, and the fusing temperature when fusing the filamentous body 1a and the tube body 3a with a mold device is The temperature is preferably about 160°C to 340°C, and the radiation irradiation conditions of the radiation irradiation device are preferably 5 Mrad or less.

It should be noted that the present invention is not limited to the illustrated embodiment, and the settings may be changed without departing from the gist of the invention. You are free to do so.

〔Effect of the invention〕

The ring seal of the present invention does not require the formation of a circular ring-shaped fluororesin semi-rigid body having a half-arc cross section and a circular ring-shaped vulcanized rubber main body, and is easy to use. In addition, since the thermoplastic fluororubber that is the main body portion 1 is crosslinked, there is no possibility of unfused seams as in conventional vulcanized fluororubber.

Therefore, this ring seal does not buckle from the seam as in the conventional case, and always has excellent sealing performance.

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view showing one embodiment of the present invention, and FIGS. 2, 3, 4, 5, and 6 are explanatory diagrams sequentially showing the manufacturing process thereof. DESCRIPTION OF SYMBOLS 1... Main body part, 3a... Tube body, 7... End surface.

Claims (1)

[Claims] 1. A solid main body made of uncrosslinked thermoplastic fluororesin is inserted into a tube made of fluororesin, and both end faces are fused to form a ring shape, and the body is heated by radiation irradiation. A ring seal characterized in that the main body portion made of plastic fluororesin is crosslinked.