JP2001208208A - Gland packing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gland packing with high stability of rotational torque, high sealing capability, and high fitting capability to a shaft. SOLUTION: The gland packing 2 is constituted by bundling plural meta- aromatic polyamide fibers impregnated with a lubricant, forming a knitting yarn 1, and braiding plural knitting yarns in a string shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a gland packing which is loaded into a stuffing box of a rotary device such as a pump or a stirrer to prevent leakage of fluid from a shaft sealing portion.

[0002]

2. Description of the Related Art Conventionally, as a gland packing used to prevent leakage from a rotating shaft (hereinafter, referred to as a shaft), inorganic fibers such as asbestos fiber and glass fiber are knitted in eight knits, sack knitting or lattice knitting. A so-called braided packing, which is braided and impregnated with a lubricant or the like or subjected to a surface treatment, is often used.

With the recent development of artificial synthetic fibers,
Numerous braided packings made of carbon fiber or para-aromatic polyamide fiber have been produced,
The properties of the gland packing, such as heat resistance, chemical resistance, and abrasion resistance, have also been greatly improved.

[0004]

However, carbon fibers and para-aromatic polyamide fibers are characterized by high strength and high modulus, but have drawbacks in that they are inferior in elongation and flexibility. Therefore, the gland packing formed by braiding these fibers is inferior to the shaft.Therefore, the gland packing is often dealt with by setting a large initial tightening surface pressure or using a large amount of lubricant. In some cases, it may be difficult to maintain the performance of the device for a long time.

Furthermore, carbon fibers and para-aromatic polyamide fibers have a problem in the production of a gland packing in that a surface treatment agent such as a lubricant is difficult to uniformly adhere to the fiber surface because the fiber surface is very smooth. .

[0006] Further, carbon fibers and para-aromatic polyamide fibers are characterized by their own hues due to their composition and crystal structure. Carbon fibers are black, and para-aromatic polyamide fibers are yellow. When gland packing using such fibers is used in food-related equipment or paper-related equipment that manufactures high-quality paper, sufficient control may be required for outflow of abrasion powder, etc. .

The object of the present invention has been made in view of the above problems, and has been made in view of the heat resistance of aromatic polyamide fibers,
While maintaining the excellent effect of chemical resistance and abrasion resistance,
An object of the present invention is to provide a gland packing which has good conformability to a shaft, is easy to be uniformly attached to a surface treatment agent, and has a white appearance.

[0008]

In order to achieve the above object, a gland packing according to the first aspect of the present invention comprises a plurality of meta-aromatic polyamide fibers impregnated with a lubricant and converged to form a knitting yarn. The gist is that a plurality of these knitting yarns are braided in a string shape.

In the gland packing according to the second aspect of the present invention, a plurality of meta-aromatic polyamide fibers are impregnated with a lubricant to converge, and these are used as a knitting yarn, and the plurality of knitting yarns are braided in a string shape. Thereafter, the gist is that the lubricant is impregnated on the surface and inside by 20 to 60% by weight by impregnation with the lubricant.

A gland packing according to a third aspect of the present invention is a solid lubricant comprising, as the lubricant, a liquid lubricant such as silicone oil or fluorine oil and a fine particle having a particle size of 1 μm or less such as paraffin or tetrafluoroethylene resin. The gist is to use.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As a preferred embodiment of the present invention, for example, as shown in FIG. 1, a liquid lubricant such as silicone oil or fluorine oil is added to meta-based aromatic polyamide fiber, paraffin or tetrafluoride. After impregnating with a solid lubricant composed of fine particles having a particle diameter of 1 μm or less such as ethylene resin and converging a plurality thereof, using the knitting yarn 1 as a knitting yarn and knitting the knitting yarn in a string shape, the lubricant Is further impregnated to form a cord-shaped gland packing 2 having the lubricant adhered to the surface and the inside in an amount of 20 to 60% by weight.

The present inventors have conducted intensive studies on the fibers used for the knitting yarns and the lubricant impregnated in the fibers in a gland packing formed by converging a plurality of fibers and knitting them into a string as a knitting yarn. As a result, a meta-aromatic polyamide fiber is used as the fiber, and a liquid lubricant such as silicone oil or fluorine oil is used as a lubricant; and a solid lubricant composed of fine particles having a particle size of 1 μm or less such as paraffin or ethylene tetrafluoride resin. By using, a gland packing that exhibits excellent effects of not only heat resistance, chemical resistance, wear resistance, but also good conformability to the shaft and the uniformity of the surface treatment agent adhesion is easy. Knowing that the present invention can be obtained, the present invention has been completed based on this finding.

This is because aromatic polyamide fibers are generally
Its molecular skeleton is roughly classified into a linear para-type and a zig-zag meta-type. The meta-aromatic polyamide fiber has heat resistance and chemical resistance due to this zig-zag molecular skeleton. While maintaining the basic characteristics of para-aromatic polyamide fiber, such as having excellent mechanical strength such as elongation and flexibility, which are insufficient, the fiber cross section and its surface properties are unique. It is presumed to be due to the soft texture and excellent adhesion of processing agents such as lubricants, and good conformability to the required shaft as a characteristic of the gland packing. ing.

A liquid lubricant such as silicone oil or fluorine oil used as a lubricant exhibits a lubricating effect immediately after tightening, and is a solid lubricant composed of fine particles having a particle size of 1 μm or less, such as paraffin or ethylene tetrafluoride resin. The agent can maintain its performance for a long time immediately after the packing is fastened due to the combined effect that a stable lubricating effect is expected for a long time.

[0015]

EXAMPLES Examples 1 to 4 and Comparative Examples 1 and 2 of the present invention will be specifically described below with reference to the structure of a cord-shaped gland packing shown in FIGS. 1 (A) and 1 (B). In addition,
(A) is a partial side view showing an embodiment of the gland packing according to the present invention, 1 is a knitting yarn, and (B) is a passage 1 of the knitting yarn 1 constituting the gland packing shown in (A).
It is explanatory drawing which shows a, 1b, 1c.

Example 1 A paraffin emulsion (Toho Kagaku Kogyo Kogyo Kogyo Co., Ltd.) was prepared by mixing meta-aromatic polyamide fiber (Cornex yarn, 500d, Teijin Ltd., 500d) with 5 parts of a silicone oil emulsion (SH490, Toray Silicone Co., Ltd.). 1 part of Parax 40K-3) was immersed in 1 part of a mixed and adjusted lubricant for 5 minutes and air-dried at room temperature for 8 hours or more.
This was used as a knitting yarn, and braided by lattice knitting using 18 of the knitting yarns to obtain a 9.5 mm square cord-like gland packing.

Example 2 A paraffin emulsion (Toho Chemical Industry Co., Ltd.) was added to 5 parts of a silicone oil emulsion (SH490 manufactured by Toray Silicone Co., Ltd.) using a meta-based aromatic polyamide fiber (Cornex yarn, 500d, manufactured by Teijin Limited). 1 part of Parax 40K-3) was immersed in 1 part of a mixed and adjusted lubricant for 5 minutes and air-dried at room temperature for 8 hours or more.
This is used as a knitting yarn, and the knitting yarn is braided by lattice knitting using 18 knitting yarns to form a string-shaped gland packing. Further, the string-shaped gland packing is dispensed with an ethylene tetrafluoride resin dispersion (Daikin Industries, Ltd.) Polyflon THE D
-1) 5 parts of paraffin emulsion (1 part of Toho Kagaku Kogyo Co., Ltd., Parax 40K-3) was immersed in a mixed lubricant for 5 minutes and air-dried at room temperature for 8 hours or more.
A 9.5 mm string-shaped gland packing was obtained.

EXAMPLE 3 A meta-aromatic polyamide fiber (Cornex yarn, 500d, manufactured by Teijin Limited) was immersed in a lubricant diluted with a silicone oil emulsion (SH490, manufactured by Toray Silicone Co., Ltd.) for 5 minutes. , 16 pieces air-dried at room temperature for 8 hours or more are converged, this is used as a knitting yarn,
This was braided by lattice knitting to obtain a 9.5 mm square string-shaped gland packing.

Example 4 Meta-aromatic polyamide fiber (Cornex yarn, 500d, manufactured by Teijin Limited) was immersed in a lubricant diluted with paraffin emulsion (Parox 40K-3, manufactured by Toho Chemical Industry Co., Ltd.) for 5 minutes. Then, 16 yarns air-dried at room temperature for 8 hours or more were converged, used as a knitting yarn, and braided with 18 knitting yarns in a lattice knitting to obtain a 9.5 mm square string-shaped gland packing. .

Comparative Example 1 A para-aromatic polyamide fiber (Cornex yarn, 500d, manufactured by Teijin Limited) was immersed in a lubricant diluted with a silicone oil emulsion (SH490, manufactured by Toray Silicone Co., Ltd.) for 5 minutes. , 16 pieces air-dried at room temperature for 8 hours or more are converged, this is used as a knitting yarn,
This was braided by lattice knitting to obtain a 9.5 mm square string-shaped gland packing.

Comparative Example 2 Carbon fiber (Bestfight yarn, 500d, manufactured by Toho Rayon Co., Ltd., 500d) was immersed for 5 minutes in a lubricant obtained by diluting a paraffin emulsion (Parax 40K-3, manufactured by Toho Chemical Industry Co., Ltd.). 1 air-dried at room temperature for 8 hours or more
Six convergences were obtained, this was used as a knitting yarn, and the knitting yarn was braided by lattice knitting using 18 knitting yarns to obtain a cord-shaped gland packing.

The gland packings obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were used as specimens P, and a high-speed rotation tester (shaft diameter 50 mm, stuffing box inner diameter 70 mm, stuffing box depth) shown in FIG. (60 mm), two sets of 5 rings each, and the packing retainer was tightened at a predetermined surface pressure. Then, the rotation torque and the leakage amount when the shaft was rotated at a peripheral speed of 4.6 m / s for 100 hours while applying a water pressure of 0.34 MPa at room temperature were measured. In addition,
In FIG. 2, 3 is a tester main body, 4 is a packing presser, 5
Is a shaft, and 6 is a torque meter.

Table 1 shows the results of measuring changes in the rotational torque and the leakage amount after the packing was tightened and after the shaft was continuously rotated in the tester.

[0024]

[Table 1]

As shown in Table 1, the gland packing obtained in the example according to the present invention has better rotation torque stability and sealing properties than the gland packing of the comparative example, and has excellent conformability to the shaft. It was confirmed that.

[0026]

As described above, according to the present invention, it is possible to obtain a gland packing capable of maintaining a stable rotation torque and a good sealing property as compared with the conventional gland packing.

[Brief description of the drawings]

FIG. 1A is a partial side view showing one embodiment of a gland packing of the present invention, and FIG. 1B is an explanatory diagram showing a passage of a knitting yarn.

FIG. 2 is a sectional view of a performance tester for a gland packing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Knitting yarn 1a, 1b, 1c Path through which knitting yarn 1 passes 2 String-shaped gland packing 3 Testing machine main body 4 Packing presser P Gland packing 5 Axis 6 Torque meter

Claims (3)

[Claims] 1. A gland packing characterized in that a plurality of meta-aromatic polyamide fibers are impregnated with a lubricant and converged, and these are used as a knitting yarn, and a plurality of these knitting yarns are braided in a string shape. 2. A method in which a plurality of meta-aromatic polyamide fibers are impregnated with a lubricant to converge, a plurality of these are used as a knitting yarn, and a plurality of the knitting yarns are braided in a string shape. A gland packing characterized in that the lubricant adheres to the surface and the inside in an amount of 20 to 60% by weight. 3. A liquid lubricant such as silicone oil or fluorine oil and a solid lubricant composed of fine particles having a particle diameter of 1 μm or less such as paraffin or tetrafluoroethylene resin are used as the lubricant. Item 3. The gland packing according to any one of Items 1 to 2.