JPH0674346A - Packing and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve cushionability, compession recovery and stress resistance relaxing performance of a cord-shaped gland packing which is manufactured by braiding using a knitting yarn, formed of a flexible expansion graphite tape and a reinforcing knitting bag unit consisting of fiber material. CONSTITUTION:A flexible expansion graphite tape 1 is coated with a knitting bag unit 2 of metal wire by a bag knitting machine, and this graphite tape- contained knitting bag unit A1 is folded in a width direction by a folding machine, comprising a male piece 3 and a female piece 4, and formed into knitting yarn A2, to constitute a cord-shaped gland packing 5 by braiding using this knitting yarn A2. In this way, since the knitting yarn A2 is formed into a sandwich structure, by integrally connecting the graphite tape and the knitting bag unit 2 through folding action, and also rich in elasticity further into a uniform fine knitting yarn, a packing braided by this knitting yarn obtains an effect of increasing cushionability, compression recovery and further stress resistance relaxing performance or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gland packing suitable for shaft sealing of fluid equipment such as valves and pumps, and in particular, a packing constituted by using a flexible expanded graphite sheet and a method for manufacturing the same. Regarding the improvement of.

[0002]

2. Description of the Related Art Conventionally, as a packing using a flexible expanded graphite sheet having good bearing property and self-lubricating property, Japanese Patent Application Laid-Open No. 4-25671 discloses an expanded graphite tape in which a mountain fold and a valley are formed in the longitudinal direction. Fold it in at least one of the folds to form a cord-like body of a folding layer, and coat the outer periphery of this cord-like body with a braided body made of stainless steel wire, Inconel wire, carbon fiber, aramid fiber, or other reinforcing yarn. There is proposed a gland packing which is made into a knitting yarn and is formed by bundling or twisting a plurality of the knitting yarns.

[0003]

According to the structure of the gland packing described above, since the folding layer obtained by folding the expanded graphite tape is a string-like body, a knitting yarn which does not cause slippage between the folding layers can be obtained. The first feature is that the expanded graphite tape is not cut during braiding for manufacturing the gland packing, so that the braiding is easy and a gland packing having a high sealing function is obtained.

Further, since the cord-like body is reinforced by the braided body of the reinforcing yarn, the integral binding force between the cord-like body and the reinforcing braided body is enhanced, and the cord-like body and the reinforcing braided body are separated from each other. The second characteristic point is that the shape retention of the knitting yarn is improved and the braiding can be facilitated to improve the sealing function of the gland packing from this point as well.

However, the gland packing having the above structure is
Since the entire folding layer obtained by folding the expanded graphite tape is covered with the reinforcing braid to form the knitting yarn, the expanded graphite and the reinforcing braid are not integrally joined together, and the cushion obtained by surely joining the both It does not maximize its properties, compression recovery rate and stress relaxation resistance.

[0006]

It is an object of the present invention to obtain a knitting yarn which further enhances the integral bonding of the expanded graphite tape and the reinforcing braid.
An object of the present invention is to provide a packing capable of maximizing the cushioning property, the compression recovery rate, and the stress relaxation resistance and a manufacturing method thereof.

[0007]

In a packing according to the first invention of the present application, a flexible expanded graphite tape is covered with a reinforcing knitted bag body made of a fiber material, and the knitted bag body containing the graphite tape is folded in the width direction. The gist is that the dented yarn is used as a knitting yarn, and a plurality of these knitting yarns are braided or twisted into a cord without a core or with a core. Further, in the packing manufacturing method according to the second invention of the present application, a step of forming a knitted bag body by knitting and covering a flexible expanded graphite tape in a bag shape with a fiber material, and a step of forming the knitted bag body containing the graphite tape in the width direction. The gist is that it comprises a step of folding it into a knitting yarn and a step of braiding or twisting a plurality of the knitting yarns without a core or with a core into a string shape.

[0008]

The knitting yarn of the above construction is formed by covering the flexible expanded graphite tape with the reinforcing knitting bag made of fiber material and then forcibly folding it in the width direction. Due to its folding action, the body becomes a structure that is firmly and integrally connected. As a result, the cushioning property of the packing braided or twisted using the knitting yarn, the compression recovery rate, and the stress relaxation resistance are increased.

[0009]

1 (a), 1 (b), 1 (c) and 1 (d) show a manufacturing process of a braided packing according to an embodiment of the present invention.

FIG. 1 (a) Flexible graphite tape 1 having a width of 7.0 mm and a thickness of 0.381 mm
Was coated with a knitting bag body 2 of SUS316 metal wire having a wire diameter of 0.1 mm by a bag knitting machine. The knitted bag body containing the graphite tape is indicated by A ₁ .

FIG. 1 (b) The knitted bag body A ₁ containing the graphite tape is attached to the male piece 3 and the female piece 4
Then, it was bent into a width of about 1/2 of the original width. As a result, the graphite tape and the knitted bag body were integrally bonded.

FIG. 1 (c) The knitting yarn A ₂ was obtained by the bending process. This knitting yarn A ₂ is pulled by the feed drive roller with a pulling force of 3 kgf.
Was stretched. By this drawing treatment, the knitting yarn A ₂ in the folded state is further narrowed down, the graphite tape is plastically deformed in the width direction, and both edges in the width direction thereof are slightly serrated from the stitches of the knitting bag body. The protrusions further strengthened the bond between the graphite tape and the metal wire. The drawing process of the knitting yarn A ₂ may be omitted.

FIG. 1 (d) Next, eight of the above-mentioned knitting yarns A ₂ are used, and the number of gears is 30 upper and 4 lower.
No. 0, 640 g 8 knitting knitting, 16 knots of 8 knitting knitting, upper 40 gears, bottom 70, 600 g of weight 0 16 g circular knitting, and then the circular knitted material in weight% : Graphite: Toluene = 6: 94: 150 Immersed in a mixed solution for several seconds and air dried for 24 hours to evaporate the solvent.
The cord-shaped braid was rolled on four points to obtain a cord-shaped gland packing 5 having a square cross section with a length of 9.5 mm, a width of 9.5 mm, and a density of 1.3 g / cm ³ .

FIG. 2 shows a string-like gland packing 7 in which the core 6 is covered with the knitting yarn A ₂ in a bag knit. The core 6 is
Flexible graphite by weight: graphite: rubber: toluene = 70: 2
The kneaded product of 0:10:19 was extruded to have a diameter of 7.4.
It was molded into a round bar with a thickness of 7.3 mm and a density of 0.
A 7 g / cm ³ bar was used. The outer circumference of this rod-like material is 16 round knitted up to 16 knitting yarns of FIG. 1 (c), the number of gears is 40, the lower 40, and the weight is 450 g.
Then, it was dipped in a mixed solution of rubber: graphite: toluene = 6: 94: 150 for several seconds, air-dried and the solvent was volatilized, and the obtained string-like body was rolled on 4 points, and the length was 9.5 mm, width 9 .5m
The gland packing has a square cross section with m and a density of 1.1 g / cm ³ .

[0015]

As described above, according to the present invention,
The flexible expanded graphite tape is covered with a reinforcing knitted bag body made of a fibrous material and then forcibly folded in the width direction is used as the knitting yarn. Therefore, the knitting yarn is composed of the graphite tape and the knitting bag body. Due to the folding action, it becomes a sandwich structure that is integrally combined, and it is rich in elasticity and is a uniform thin knitting yarn, so the packing obtained by braiding or twisting with this knitting yarn has a cushioning property. The excellent effects such as increase in the compression recovery rate, increase in the compression recovery rate, increase in stress relaxation resistance, and reduction in the number of maintenances are exhibited.

Further, according to the packing manufacturing method of the present invention,
The step of covering the flexible expanded graphite tape with the reinforcing knitted bag body and the step of folding the knitted bag body containing the graphite tape are simple and easy operations, and can be performed continuously,
The packing manufacturing workability can be improved and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a packing manufacturing process diagram showing an embodiment of the present invention, in which (a) is a perspective view of a knitted bag body containing a graphite tape;
(B) is an explanatory view of a folded state of the knitting bag containing the graphite tape, (c) is a perspective view of a knitting yarn obtained by folding, and (d) is a perspective view of a gland packing formed by braiding with the knitting yarn. Is.

FIG. 2 is a perspective view of a gland packing showing another embodiment of the present invention.

[Explanation of symbols]

A ₁ Knitted bag containing graphite tape 1 Flexible expanded graphite tape 2 Reinforced knitted bag made of fiber material 3 Male piece 4 Female piece A ₂ Knitting yarn 5 Braided packing 6 Braided packing with center core

Claims (2)

[Claims] 1. A flexible expanded graphite tape is covered with a reinforcing knitted bag body made of a fibrous material, and the knitted bag body containing the graphite tape is folded in the width direction to form a knitting yarn. The packing is characterized in that it is braided or twisted into a cord without a core or with a core. 2. A step of knitting a flexible expanded graphite tape into a bag shape by covering it with a fiber material to form a knitted bag body, and a step of folding the knitted bag body containing the graphite tape in a width direction to form a knitting yarn. And a step of braiding or twisting a plurality of the knitting yarns without a core or with a core to form a cord.