Rubber Chem Encyclopedia

Reduce the amount of sulfur Recycled rubber products can avoid sulfur spray?

Create Date:2018-12-25 08:56:57Click volume:111
Reduce the amount of sulfur Recycled rubber products can avoid sulfur spray?

Although the reclaimed rubber processed from waste rubber products undergoes a desulfurization process in the production process, the finished reclaimed rubber itself also contains a small amount of vulcanizing agents, accelerators and other components that are not completely removed. When the rubber product manufacturers design reclaimed rubber products, It is necessary to calculate this part of the compounding agent. Otherwise, the amount of sulfur used is too much, and it is easy to cause sulfur spray. However, in actual production, the problem of sulfur injection occurs in the recycled rubber product, just because of excessive sulfur, how to avoid the problem of sulfur injection. ?

Q: What is sulphur?

A: The so-called sulphur spray is simply a phenomenon in which excessive sulfur is deposited on the surface of the reclaimed rubber compound to form crystals. There are many types of reclaimed rubber products, and the solubility of sulfur in reclaimed rubber of different varieties and different indexes is different; For example, the general latex rubber and natural rubber have the most similar molecular structure and performance characteristics. Therefore, sulfur is easily dissolved in the latex reclaimed rubber. As the processing temperature increases, the solubility of sulfur in the latex reclaimed rubber increases, but the temperature increases. After the lowering, the solubility of sulfur in the latex reclaimed rubber will also decrease, and the sulfur exceeding the solubility will precipitate on the surface of the rubber.

Q: What are the hazards of sulfur injection in recycled rubber products?

Answer: When using rubber produced by recycled rubber, the problem of sulfur injection occurs. The most obvious is the discoloration and migration of the rubber surface, which causes the appearance of rubber products to be damaged. The problem of sulfur injection during the production of recycled rubber products will also cause the adhesion of the rubber surface to decrease. As a result, the rubber cannot be tightly bonded to other parts of the rubber product, causing irreversible damage to subsequent production.

Q: What are the causes of sulfur spray on recycled rubber products? Just because of excessive sulfur?

A: In theory, the reason why the sulfur injection problem occurs during the processing of recycled rubber products is that the sulfur consumption exceeds the solubility in the rubber compound. The simplest explanation is the excessive sulfur, but this is not the main reason; the mixing temperature Excessively high, long parking time, and severe sulfur sulphur can cause sulphur spray problems in recycled rubber products.

Q: How to solve the problem of sulfur spray on recycled rubber products?

A: At the beginning of the article, we have already mentioned that there is a certain amount of vulcanizing agent in the reclaimed rubber itself. Therefore, when designing the reclaimed rubber product formula, it is necessary to calculate this part of sulfur to avoid the excessive amount of sulfur in the reclaimed rubber formula to cause sulfur injection; Reduce the mixing temperature, control the refining glue mixing temperature below the melting point of sulfur, ensure uniform mixing, reduce the probability of sulfur sprayed by reclaimed rubber; add some specific softener after refining rubber mixing and then add sulfur; The proper amount of channel black carbon can be used; the appropriate amount of selenium can be used together with the reclaimed rubber product with sulfur as the main vulcanizing agent; the replacement of ordinary sulfur with insoluble sulfur can obviously alleviate the problem of reclaimed rubber spray.

In fact, compared with the original rubber, the probability of the sulphur-spraying problem of the reclaimed rubber itself is low, and many rubber product manufacturers will choose to use a small amount of reclaimed rubber in the rubber product formulation to reduce the probability of sulphur injection; therefore, the reclaimed rubber is used. The rubber products manufacturers of the main raw materials do not have to worry too much.