Komatsu 721-98-00590 7219800590 Bucket Cylinder Seal Kit Fits PC490LC-10 PC490HRD-11E0 Bucket Cylinder Repair Kit

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What Characteristics Should The Material Of The Seal Have?

Seals are materials or parts that prevent fluids or solid particles from leaking from adjacent joint surfaces and prevent foreign impurities such as dust and moisture from intruding into the internal parts of the machine and equipment. The storage room temperature of the seals is best to be below 30 degrees Celsius to avoid sealing High temperature aging phenomenon of parts;

Seals are usually made of elastic natural rubber or synthetic rubber. Synthetic rubber is cured by a combination of various chemical ingredients. The ingredients generally fall into the following C.A.Tegories: polymers, inert fillers, reinforcing agents, C.A.Talysts, anti-degradants , Plasticizers, process aids to promote forming. Selecting the characteristic combination of ingredients and the ratio can be made into synthetic rubber materials suitable for various specific engineering appliC.A.Tions.

Now let's make some classifiC.A.Tion and summary of the characteristics of the rubber materials used to make seals:

1. Resilience: the best is natural rubber;

2. Tensile strength: natural rubber and polyurethane rubber have high tensile strength;

3. Compression and permanent deformation resistance: urethane polyurethane ester, silicone, fluorocarbon rubber are better;

4. Corrosion resistance: natural rubber, styrene butadiene, propylene ethylene, neoprene, nitrile, and polyurethane rubber have excellent corrosion resistance;

5. Cold and heat resistance: best propylene ethylene, silicone and fluorosilicone rubber;

6. Acid resistance: fluorocarbon rubber is the best, polyacrylate and polyurethane rubber are poor in acid resistance;

7. Oil resistance: polyacrylate, nitrile, and fluorocarbon rubber have excellent oil resistance.

Common failure causes and improvement measures of seals:

The failure of seals due to raw materials is mainly manifested in two aspects: improper material selection and quality problems in the material itself. When the sealing material is not compatible with the fluid, the rubber absorbs the liquid and swells, resulting in permanent deformation; or the rubber material If the hardness is improperly selected and the elasticity is not good, it will not be able to play a sealing role, resulting in seal failure and leakage.

Considering the convenience of process operation, materials that can theoretically achieve the performance of rubber seals are selected, but the rubber seals fail due to the formulation or vulcanization process. Or the selected rubber friction coefficient is not suitable, the rubber compound is mixed unevenly or impurities are accidentally mixed in the mixing process, the amount of additives exceeds the standard or segregation, pores, porosity, and poor interface between the reinforcing agent and the matrix material. , will cause the performance of the seal to decline and fail.