Technical Glossary Oil Bleed, Silicone Oil

[Oil Bleed, Silicone Oil]

Certain plastics and rubbers are softened by the addition of oils (plasticizers) to their base mixture. When used, plasticizers can separate and bleed out of the material surface. This is called bleeding or oil bleed. There is a similar phenomenon called blooming, when solid additives appear as a powder on the material surface.
Bleeding and blooming are usually avoided due to their negative effect on the appearance and texture of materials. However, there are also silicone products which use these phenomena to their advantage. For example, self-lubrication can be achieved by mixing incompatible silicone oils, which produces continuous oil bleeding in the product.