KR930011259B1 - Filling material for spiral winding gasket - Google Patents

Abstract

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Description

Filling material for spiral winding gasket

1 is a cross-sectional view of a spiral winding gasket.

* Explanation of symbols for main parts of the drawings

1 hope 2 filler

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to filler materials for spiral wound gaskets, and more particularly to fillers suitable for spiral wound gaskets used for sealing high temperature fluids such as automobile exhaust gas.

As shown in FIG. 1, the spiral winding gasket is formed by winding a belt-shaped hoop material 1 and the filler 2 in a spiral winding a plurality of times, and generally between the connection flanges. It is used to seal.

This type of filler is generally made of inorganic paper obtained by weaving inorganic fibers. However, asbestos fillers have traditionally been used in spiral wound gaskets used under high temperature conditions.

However, in recent years, the use of asbestos tends to be restricted or prohibited from the viewpoint of hygiene and pollution of the human body. In other words, asbestos, due to its nature, it is easy to generate a large amount of dust during handling, which may cause lung cancer or asbestos disease or mesothelioma in which asbestos dust is deposited on lungs or skin. It is being done. Moreover, asbestos is a pollution source, and regulations on the global environment are only tightened year by year.

Therefore, the development of the filler which does not use asbestos is strongly requested | required, and the non-asbestos filler which used glass fiber, for example is proposed conventionally.

However, in the case where the glass fiber is used, the glass fiber melts and shrinks, so that the glass fiber cannot be used under a high temperature condition of 600 ° C. or higher, and thus it is hardly applicable to a high temperature fluid such as automobile exhaust gas.

Thus, in terms of heat resistance, it is a fact that not only the superior asbestos filler but also a substitute for this have not been proposed yet.

An object of the present invention is to provide a filler of a spiral wound gasket which can be sufficiently used as an alternative to an asbestos filler, and which has better heat resistance than an asbestos filler.

The purpose of the present invention is not less than 36.5% by weight of fibrous material consisting of 5 to 20% by weight of ceramic fiber, 13.5 to 25% by weight of sepiolite (also called disintegrated stone) and 1 to 10% by weight of organic fiber, and 59% by weight or less. Achievement by forming with an inorganic powder and a binder of 1 to 10% by weight, by using a filler of such a configuration can meet the request of the era of non-asbestos, and asbestos filler It is possible to provide a gasket using a spiral wound gasket capable of exhibiting a suitable sealing function even under high temperature conditions.

The fibrous material is blended to impart resilience and strength to the filler, but if less than 36.5% by weight, sufficient resilience and strength cannot be secured. Therefore, the compounding quantity was 36.5 weight% or more. Usually, it is preferable to set it as weight% or less so that the porosity in a filler may not become high, ie, sealing property is not impaired.

The fibrous material is composed of ceramic fiber, sepiolite and organic fiber. The ceramic fiber has a fiber diameter of about 1 to 5 µm, and forms a mesh-like structure inside the filler and has excellent heat resistance. It gives a stable strength to the fillers regardless of the time of heating and heating. On the other hand, when the ceramic fibers are interlocked or compressed, the fibers are broken. In view of such a point, the blending amount of the ceramic fiber was 5-20% by weight.

In addition, as a sepiolite, the alpha type thing which has a fiber diameter of about 0.2 micrometer is used. Sepiolite forms a dense net-like structure inside the filler. Sepiolite retains its solidity at room temperature and exhibits sintering properties as it is heated, and thus functions as a binder having heat resistance. Such a function is not fully exhibited when the blending amount is less than 13.5% by weight. Sepiolite does not bend fibers like ceramic fibers, but when the blending amount exceeds 25% by weight, the filler becomes harder than necessary, and the sealing property is lowered. For this reason, the blending amount was 13.5% by weight.

Moreover, hemp pulp etc. are used as organic fiber. The organic fiber forms a net-like structure inside the filler at room temperature, thereby securing the strength required for the preparation of the filler or during the manufacture of the gasket. However, when the blending amount is less than 1% by weight, sufficient strength can be obtained. none. However, when the compounding quantity exceeds 10 weight%, the heat resistance of a filler or a gasket will be impaired.

For this reason, the blending amount is set to 1 to 10% by weight.

As the inorganic powder, talc, calcium carbonate, clay, barium sulfate and the like are used, and the inorganic powder is blended to improve the sealing property of the gasket. For example, talc is a flexible mineral in the form of flakes, which is densely packed in a mesh-like structure by a fibrous material to improve sealing properties. Although the compounding quantity of an inorganic powder is 59 weight% or less, More preferably, it is 45.5 weight% or more.

As a binder, natural, synthetic rubber latex, resin emulsion, etc. are used, but in order to extract the function as a binder, 1-10 weight% is mix | blended.

Hereinafter, embodiments of the present invention will be described in detail.

As an example, the filler I which forms the blending composition shown in Table 1 and the blending composition shown in Table 6, and the filler V which forms the blending composition shown in Table 7 by the initial bath were obtained. Moreover, as a comparative example, filler II of the compounding composition shown in Table 2 and filler III of the compounding composition shown in Table 3 were obtained with an initial bath. Filler II is of the same composition as filler I, except that glass fiber is used instead of ceramic fiber, and filler III is a conventional asbestos filler. The bulk density was 1.0 g / cm 3 for fillers I, IV, V, and II, and 0.82 g / cm 3 for filler III. Using the fillers I, IV, V, and III thus obtained, spiral wound gaskets (see FIG. 1) having an inner diameter of 43.5, an outer diameter of 57 mm, and a thickness of 5.0 mm were prepared, respectively, and the seal characteristics test and the impact resistance characteristics of each gasket. Test was made.

The seal characteristic test measures the amount of nitrogen gas leaking to the outer circumferential side of the gasket by inserting 0.5 kg / cm 3 of nitrogen gas into the inner circumferential side of the gasket while the gasket is joined so that the thickness thereof is 4 mm. In addition, the leak amount of nitrogen gas guides the leaked nitrogen gas to a measuring cylinder, and is measured by the moving speed of the soap film in this graduation cylinder.

In the impact resistance test, a weight of 200 g is dropped from a height of 500 mm on a gasket, a shock is placed in the direction of the gasket, and the dropping of the filler after repeated 50 times (that is, scattering of the filler due to the impact of the weight) is performed. The loss by) is measured, and the impact strength of the filler is evaluated by this. That is, the smaller the weight loss (dropping amount) of the filler due to the impact, the greater the impact resistance.

These characteristic tests were carried out at room temperature, and after filling the fillers, that is, the gaskets at 400 ° C, 600 ° C, and 800 ° C for 3 hours, respectively, the results shown in Tables 4 and 5 were obtained.

As can be understood from the test results of the sealing properties shown in Table 4, in the gaskets using the fillers II and III, the sealing properties significantly decreased after 800 ° C heating. This is attributable to the fact that the glass fibers of the filler II melt and shrink by being heated to 800 ° C., and the asbestos of the filler III discharges the crystal water. On the other hand, in the gasket using the fillers I, IV, and V according to the present invention, the sealing property is not impaired even under a high temperature condition of 800 ° C., and the same sealing function as in the condition of 600 ° C. or less can be exhibited.

In addition, as can be understood from the test results of the impact resistance characteristics shown in FIG. 5, in the filler II using glass fiber, the weight loss due to dropping after 800 ° C heating is large, resulting in a significant decrease in strength at high temperature conditions. On the other hand, although fillers I, IV, and V are inferior to filler III in 600 degrees C or less, on the conditions after 800 degreeC heating, the loss by falling out of filler III is less and excellent in intensity | strength.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

Claims (5)

(1) at least 36.5% by weight fibrous material consisting of 5 to 20% by weight of ceramic fibers, 13.5 to 25% by weight of sepiolite, and 1 to 10% by weight of organic fibers, (2) inorganic powders of not more than 59% by weight, and (3) Filler of a spiral winding gasket comprised from 1 to 10 weight% binder. The filler material for a spiral wound gasket according to claim 1, wherein the organic fiber is hemp pulp. The filler material for a spiral wound gasket according to claim 1, wherein the inorganic powder is selected from talc, calcium carbonate, clay, and barium sulfate. The filler material for a spiral winding gasket according to claim 1, wherein the ceramic fiber has a fiber diameter of 1 to 5 mu m. 2. The filler material for a spiral wound gasket according to claim 1, wherein the sepiolite is α-sepiolite and has a diameter of about 0.2 mu m.