Blooming effect
What is the blooming effect?
During blooming—also known as “Ausblühen” in German—soluble components migrate from the interior of the elastomer to the surface. There, they deposit as a fine, often whitish film. This is caused by components in the compound that are not fully bound within the material and migrate over time or under the influence of temperature. This effect is particularly noticeable during prolonged storage. It is a surface phenomenon and, in and of itself, says little about the mechanical quality of the O-ring.
Why the Blooming Effect Is Important for O-Rings
Visually, an O-ring that has bloomed often looks dirty or worn, which can lead to complaints during goods receipt, even though its function is usually not impaired. In sensitive applications, such as in the food or pharmaceutical industries, this residue is nevertheless undesirable because it could contaminate the medium. A carefully formulated compound with well-bound components reduces blooming. Proper storage in accordance with DIN 7716 also helps to minimize this effect.
- Blooming is a light-colored coating of migrating mixture components on the surface.
- It is usually a visual phenomenon and generally does not affect function.
- However, this coating should be avoided in food and pharmaceutical applications.
The data sheets indicate which compounds are suitable for sensitive applications. You’ll find approved materials for food and pharmaceutical applications in our product line.
You can find the right material for your application in our product range.