Failure analysis of rubber seals


There are four common causes of failure for rubber seals: design errors, material selection errors, seal quality issues, and improper use.

1. Design errors are usually caused by designers having insufficient understanding of the product.

For example, insufficient estimation of the pressure borne by the sealing element, incorrect understanding of the distribution of contact stress on the sealing surface, and unreasonable design of the groove for placing the sealing element. Finite element analysis (FEA) is often used to assist in the design and failure analysis of seals.

2. Material selection error

Common rubber sealing materials include EPDM, NBR, VMQ, FKM, and CR. These rubbers have different characteristics and applications. The selection of materials should be considered from multiple aspects, such as the temperature of use, whether the material is resistant to the medium, the hardness of the material, compression permanent deformation, and wear resistance.

Material selection errors are often caused by designers being unfamiliar with the performance of various materials. An experienced rubber seal supplier can point out material selection issues from the beginning.

3. Seal quality

The production quality of seals is closely related to the reliability of the final product. Common problems include unstable raw material quality, incorrect feeding of raw materials during rubber mixing, improper storage of raw materials or mixed rubber (cross contamination), uneven mixing of rubber materials, improper vulcanization conditions (temperature, time, pressure, etc.), improper storage of sealing products, and improper use of molds. These issues often involve quality control in the production process. The ordering party should conduct multiple inspections, research, and product testing when selecting a sealing component manufacturer. During the supply process, the manufacturer of the seal can also be required to provide a true and accurate inspection report.

4. Improper use of seals

A good seal, if used improperly, can also cause the entire product to fail, such as incorrect use of lubricating oil.

Another common problem is installation errors. For example, distortion occurred during the assembly process of the O-ring; Uneven compression of the sealing element due to improper installation; Insufficient lubrication of seals and other errors. If these errors are caused by the manufacturer of the seals, then this is considered a matter of production quality


Post time: Mar-06-2024