JPS6147878B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a packing having excellent properties in terms of sealing effect, thermal stability, and lubricating effect, and particularly relates to a packing for a rotating shaft sealing device such as a pump or an agitator. Conventionally, natural fibers such as cotton, hemp, and asbestos have been used as gaskets for water-based fluids. However, cotton and linen have poor heat resistance, and in recent years have become unable to meet the usage conditions required for packing materials.In addition, asbestos is a material that will no longer be used as a raw material for packing materials, as the dust generated during manufacturing and processing has an adverse effect on the human body. It is expected that it will become difficult to obtain. For this reason, various chemical fibers such as polypropylene, polyester, polyamide fibers, and polynosic fibers have been devised, but tests have shown that these chemical fibers shrink due to heat generated by sliding with the rotating shaft. It has been found that the range of use is extremely limited because phenomena such as softening, melting, etc. occur, and the properties are unfavorable as a packing material. Furthermore, it appears that the packaging made using these chemical fibers is actually provided to the industrial market and does not contribute to the industry. The present invention was made in view of these drawbacks and circumstances, and focuses on cellulose triacetate fibers that are commercially available for clothing, and uses triacetate fibers that are made heat resistant by subjecting these fibers to a predetermined treatment. Furthermore, in order to obtain the sealing effect and lubricity of the packing, we provide a packing that has excellent sealing effect, thermal stability, and lubrication effect by impregnating the fiber gaps with lubricant and applying impervious treatment such as interposition. The purpose is to That is, the present invention involves tightly bundling a large number of fiber base materials to form a knitting yarn, forming a packing body by braiding a plurality of the knitting yarns, and adding a lubricant to the outer surface and internal gap of the packing body. This is a triacetate fiber packaging in which the fiber base material is triacetate fiber spun from secondary cellulose acetate obtained by partially hydrolyzing cellulose triacetate by solvent treatment. The present invention will be explained in detail below. The main raw material of the present invention, "triacetate fiber with heat resistance", is commonly called "acetate rayon", "cellulose rayon",
It is not a fiber that means "cellulose triacetate." In other words, rayon, which is a recycled cellulose fiber, and acetate, which is a semi-synthetic fiber, are different fibers in terms of production method and properties, and the term "acetate" generally refers to cellulose triacetate, which is obtained by acetylating the three hydroxyl groups of cellulose. "triacetate fiber with heat resistance" of the present invention
is a triacetate fiber (Soalon manufactured by Mitsubishi Rayon Co., Ltd.) obtained by dry spinning this cellulose triacetate, which is further hydrolyzed in part by treatment with a solvent (mixed solution of methylene chloride and methanol) to obtain secondary cellulose acetate. It has excellent heat resistance, and has a high strength retention rate even when held for long periods in high-temperature atmospheres. Incidentally, Table 1 shows the results of comparative experiments on strength retention by dry heat.

[Table] In addition, the "triacetate fiber with heat resistance" that is the raw material for the packing material of the present invention can be further provided with excellent properties that meet the characteristics required for the packing material, and can be processed by wet or dry processing after the above-mentioned solvent treatment. By holding the product in an atmosphere of 200℃ to 300℃ for a certain period of time, 1) Heat resistance increases slightly. (Softening temperature increases) 2) Decreased swelling property. 3) It was confirmed that it can be improved to have properties such as a reduction in shrinkage rate. Therefore, as mentioned above, the "triacetate fiber with heat resistance" which is a raw material for packing of the present invention refers to a fiber that has been improved in various ways and is extremely suitable as a packing material (hereinafter referred to as "T fiber"). . Here, to explain the basic structure of the packing of the present invention based on the drawings, the above-mentioned T fiber is used as the base material 1, this base material 1 is tightly bundled in a large number to form the knitting yarn 2, and the knitting yarn 2
A packing main body 3 is formed by braiding (square knitting, lattice knitting, twisting, etc.) a plurality of the packing main bodies 3, and lubricants 6, 7 are applied to the outer surfaces 4, 4' and internal gaps 5, 5' of the packing main body 3. This is a package obtained by dispersion. Therefore, since the packing body 3 is fibrous, the lubricants 6 and 7 can be uniformly dispersed arbitrarily and freely in the gaps formed in the packing body 3, and after tightening, the packing becomes extremely uniform in density. The lubricants 6 and 7 may be selected from heat-resistant grease 6 or solid lubricant 7 alone or in combination depending on the purpose. In addition, when impregnating the lubricants 6 and 7, it may be carried out when a large number of the above-mentioned T fiber base materials are tightly bundled. You may. Next, an example in which the packing of the present invention can be suitably implemented will be described. Example 1 Using T fiber as a base material, this base material was tightly bundled into a large number of fibers, and four types of heat-resistant grease solid lubricants (graphite, mica, talc, and tetrafluoroethylene resin particles) were combined with heat-resistant grease. A knitting yarn is made by applying an impermeable treatment using a mixture of
12 types were formed. Example 2 Using T fiber as a base material, this base material is tightly bundled into a large number of yarns to form a knitting yarn, and multiple yarns are tied together and braided (for three types: square knitting, lattice knitting, and twisting). A packing body was formed using the above method, and a solid lubricant was dispersed in the outer surface and the internal gap of the packing body. In this case, a total of seven types of solid lubricants were selected: tetrafluoroethylene resin particles (impregnated with an aqueous suspension to remove moisture), silicone resin particles, heat-resistant liquid paraffin, metal fine particles, and graphite particles. Dozens of types of packings were prepared using either a single agent or a mixture of two types of agents. Experiments were conducted on the gaskets formed in Examples 1 and 2 above, and they all had excellent sealing effects and lubricity, and there was almost no difference in the performance of the gaskets, and it was found that the gaskets should be selected appropriately depending on the intended use. confirmed. Example 3 T fiber (in this case Soalon manufactured by Mitsubishi Rayon Co., Ltd. was used), 200 denier, 52 filament was used as the base material. After tightly converging this base material into many fibers, heat-resistant grease and four-layered filament were used. The knitting yarn was made impermeable using a lubricant mixed with ethylene chloride resin particles, and an 8 mm square string was formed by eight-stroke square knitting, which was then molded using a roller to obtain a patch. . This packing was more flexible than the conventional braided packing made mainly of asbestos. It was also confirmed that it had excellent lubricity. That is, shaft diameter 20mmφ,
As a result of an experiment as a gland packing for shaft sealing of a rotary pump with a shaft rotation speed of 3600 r.pm and a circumferential shaft speed of 3.77 m/s, the requirements of the packing of the present invention were confirmed under conditions of room temperature water and water pressure of 6 kg/cm ² G. The torque is 0.24Kg・m, whereas the torque is 0.64 for the conventional packing made of asbestos.
It was Kg・m. (In this case, the amount of leakage was the same and both the seals were good.) Therefore, the seal of the present invention has excellent lubricity and is significantly advantageous in preventing heat generation and deterioration of the seal. I understand that. As mentioned above, the packing material of the present invention uses fiber as its main raw material, which is available in large quantities at a low price, similar to asbestos.
Since this is a gasket that has been improved in terms of material and structure so that it has the various properties required for a gasket, it has extremely high industrial utility value compared to conventional products.

[Brief explanation of the drawing]

The drawing is a sectional view of a packing showing an example of a suitable packing of the present invention. 1... Base material, 2... Knitting yarn, 3... Packing body,
4, 4'...Outer surface portion, 5, 5'...Internal gap, 6...Lubricant (heat-resistant grease), 7...Lubricant (solid lubricant).

Claims (1)

[Claims] 1 A large number of fibrous base materials are tightly bundled to form a knitting yarn, a plurality of the knitting yarns are braided to form a packing body, and a lubricant is dispersed and interposed between the outer surface and the internal gap of the packing body. In Patsukin,
A triacetate fiber packing characterized in that the fiber base material is triacetate fiber spun from secondary cellulose acetate obtained by partially hydrolyzing cellulose triacetate by solvent treatment.