What Is Rubber Blooming And What Causes It?

You might find it amusing, but not all the defects in rubber are considered bad. Rubber blooming (white milky powdered film on the surface of rubber) is one such defect in rubber that people often consider bad. But in reality it is supposed to be there. One of the real-life examples of this white milky substance on the rubber surface can be found in the new tires. This small dull film of white milky substance can be easily wiped out revealing the fresh black tire underneath it.

This bloom typically will not affect the performance of rubber, instead, it offers ozone protection to the rubber.

What Causes Blooming In Rubber?

All the rubber materials degrade with exposure to external environmental factors. Oxygen, heat, and UV, are remarked as the factors that cause free radicals to form, which attach to the polymer chains and cleavage bonds in rubber, and result in weak cross-linking making rubber hard.

To avoid this and make sure rubber will not lose its characteristics, antioxidants are added to the rubber mixture. It will help to scavenge free radicals that are hurting the characteristics of rubber. These antioxidants will ultimately come out on the surface, causing defects on the rubber surface making it look dull, causing the bloom.