Abrasion

The term "abrasion" refers to the wear process in which material is removed from the surface of components through mechanical action. In the context of elastomers or their products such as seals, O-rings, hoses or various molded parts, abrasion is a critical aspect that significantly influences the service life and reliability of these components. The wear behavior or material loss is influenced by the mixture composition as well as the design and the type of stress. Where seals are used, abrasion of the material can occur in both static and dynamic sealing applications.

abrasion of static seals

In static sealing applications, where there is no continuous movement between the components being sealed, wear is caused by the subtle but effective movements of the sealing element within its installation environment. For example, O-rings or other sealing elements that do not move obviously can nevertheless be slightly displaced along the sealing surfaces. This happens, for example, due to:

• Changing pressure conditions : Fluctuating pressures within the system can cause the sealing ring to move slightly within its groove. This movement, although slight, is enough to cause abrasion on the sealing surfaces.
• Surface finish of sealing surfaces : The condition of the surfaces with which the sealing ring comes into contact plays a crucial role. Rougher surfaces increase the likelihood of abrasion, while smoother surfaces minimize the risk.
• Cyclic pressure changes : Especially under extreme and repetitive pressure conditions, the sealing ring experiences a kind of micro-movement within its guide groove, which further increases the abrasion.

Abrasion in dynamic seals

In dynamic sealing applications, where sealing elements move relative to other components or slide continuously over the contact surfaces of the components, the abrasion is much greater than in static applications - here it is a natural consequence of friction. In this context, there are factors that increase the abrasion on dynamic seals:

• Low surface quality : Relatively rough surfaces accelerate abrasion. On the other hand, the smoother the surface of the running surfaces, the lower the friction and thus the abrasion of the sealing material.
• Lack of or insufficient lubrication : Here too, the thermal load is increased by friction, so that seals wear out faster.
• Hard particles : Small particles in the media in contact with dynamic sealing applications can have an abrasive effect on the elastomer material, thus leading to further abrasion. These can be, for example, metal chips that are in the lubricant.

Reduction and testing of abrasion on elastomer materials

Careful selection of the sealing material and management of sealing conditions are critical to minimize abrasion and maximize the life of the material. Specially developed elastomer compounds can be specifically optimized for improved abrasion resistance.

To assess abrasion resistance, standardized abrasion test procedures are used, which make it possible to test different elastomer materials under comparable conditions. These tests are essential both for the development of new elastomer products and for quality assurance.