Rubber can be divided into unvulcanized rubber (hereinafter referred to as rubber material) and vulcanized rubber (hereinafter referred to as product), and rubber frosting includes surface frosting of rubber material and surface frosting of product. Bloom is the phenomenon of liquid or solid compounding agents migrating from the inside of rubber to the surface of rubber. It can be seen that the compounding agents inside the rubber precipitate, forming a spray. There are generally three types of rubber frost spraying. That is, powder spraying, wax spraying, and oil spraying (also known as exudation).
Powder spraying is the precipitation of powder like additives such as vulcanizing agents, accelerators, activators, antioxidants, fillers, etc. on the surface of rubber, forming a layer of powder like substance. Wax spraying is the precipitation of wax like substances such as paraffin and floor wax on the surface of rubber, forming a wax film. Oil injection is the precipitation of liquid additives such as softeners, tackifiers, lubricants, and plasticizers on the surface of rubber, forming a layer of oily substance.
Rubber frosting is due to the fact that after the rubber internal ingredients reach the Supersaturation state, the ingredients near the surface of the rubber will first precipitate, and then migrate from the inner layer to the surface layer. When the ingredients in the rubber are reduced to its saturated state, the precipitation process will end. The main reasons for the formulation to reach Supersaturation state and rubber frosting are: improper rubber formulation design, improper process operation, fluctuations in raw material quality, poor storage conditions, product sulfur deficiency, product aging, etc.