The blooming of rubber products is the appearance of liquid or solid compounding agents moving from the inside of the rubber to the outside of the rubber. Rubber frosting includes frosting on the surface of the rubber and frosting on the surface of the product. It can be seen that the internal compounding agent of the rubber is separated, which constitutes a spray, and the rubber surface spray has a complex composition, and is rarely a single one. There are always primary and secondary components in the complex components of blooming, because the compounding agents affect each other in the rubber. As long as one compounding agent is sprayed out, the uniformity of the entire compounding agent in the rubber will be destroyed, and a concentration gradient will be generated. It is easy to eject the other compounding agent along with the ejection of the former compounding agent. Therefore, in order to prevent blooming, we must first analyze the main components in blooming, and then take measures to prevent it according to the cause of blooming.

(1) Adjust the formula
Blossom mainly depends on the formula design of the rubber. If the dosage of compounding agent exceeds its maximum dosage in rubber during formulation design, it will cause blooming on the rubber surface.

First, limit the dosage of compounding agents: When formulating, the dosage of compounding agents must be limited to the maximum amount allowed by the conditions of rubber storage and use (including temperature, pressure, medium, humidity, etc.). To this end, a compounding agent with a solubility parameter close to that of the raw rubber can be selected; or several compounding agents can be used in combination, which not only achieves the same effect, but also avoids the blooming of the compounding agent.

Secondly, improve the type of raw rubber: the same compounding agent has different solubility in different raw rubbers, and different raw rubbers have different solubility parameters. For this reason, in the case that the rubber properties meet the requirements of use, the raw rubber with high solubility can be selected or used in combination; the raw rubber with similar solubility parameters to the compounding agent is selected; Dosage and other measures to avoid the blooming of the compounding agent.

(2) Improve the process
First, improve the dispersibility of the compounding agent: improve the dispersibility of the compounding agent in the rubber by reducing the mixing temperature, prolonging the mixing time, increasing the number of thin passes, the number of cuts, or adding a dispersant (homogeneous agent) to the formula. to disperse it evenly.

Secondly, improve the degree of vulcanization of the product: increase the degree of vulcanization by extending the vulcanization time and increasing the vulcanization temperature, so as to avoid the blooming caused by the lack of sulfur of the product.

(3) Improve storage conditions
First of all, to improve storage conditions and avoid rubber frosting, the following measures should be taken. Reduce the storage temperature and strictly prohibit sunlight; reduce the air humidity, make the storage environment dry and ventilated; shorten the inventory cycle and avoid long-term storage; avoid rubber squeezing and rubbing each other, so that they can be placed alone or on a shelf.