As a traditional rubber variety, natural rubber occupies an important position in the rubber product industry and is widely used in various industries. When using natural rubber to produce rubber products, sulphur spraying is a common problem, which directly affects the appearance, bonding strength and quality of the natural rubber products. In actual production, there are many reasons that cause sulfur to precipitate on the surface of natural rubber. Rubber product manufacturers need to take appropriate measures to deal with the cause of sulfur injection.
1. The solubility of sulfur in natural rubber
Sulfur can be easily dissolved in natural rubber. The higher the temperature, the higher the sulfur solubility. When the amount of sulfur in the natural rubber product formulation is in a supersaturated dissolved state, the excess sulfur 2LLYY831 will precipitate on the surface of the rubber compound; when the ambient temperature decreases, the solubility of sulfur in the natural rubber decreases, and the excess sulfur will also precipitate on the surface.
In the actual production process, when the dissolution temperature is 20℃, 100g natural rubber can dissolve 1g sulfur; when the dissolution temperature is 29℃, 100g natural rubber can dissolve 1.5g of sulfur; when the dissolution temperature is 39℃, 100g natural rubber can dissolve 2g Sulfur: When the amount of sulfur continues to increase, at a certain temperature, sulfur may precipitate on the surface of natural rubber. Theoretically, if 1-2 parts of sulfur are used in 100 parts of natural rubber, there will be basically no sulfur spray.
2. Reasons for vulcanization of natural rubber
When natural rubber is vulcanized with sulfur, the excessive amount of sulfur itself is one of the reasons for the vulcanization phenomenon; when natural rubber is mixed, uneven mixing and high mixing temperature cause uneven sulfur dispersion, and excessive amount of sulfur precipitates on the surface. ; When the natural rubber compound is parked, the solubility of the rubber or the local rubber exceeds the saturated solubility limit or the supersaturated solubility limit at room temperature, and sulfur will crystallize out of the rubber; if the sulfur is improperly combined or is severely under-sulfur, natural Rubber products can also suffer from vulcanization problems.
Sulfur spraying of unvulcanized natural rubber will seriously affect the uniformity of sulfur distribution in natural rubber. It will not only affect the appearance of natural rubber products, but also cause a sharp decline in the adhesion and anti-aging properties of natural rubber. Therefore, rubber products manufacturers must adopt Certain measures should be taken to avoid the problem of sulphur spraying in natural rubber, especially in rubber products with a large amount of sulphur.
Specific problems are analyzed in detail. Rubber products manufacturers need to analyze the causes of natural rubber vulcanization and take corresponding measures. Tomorrow, the editor will continue to discuss solutions to the problem of natural rubber vulcanization.
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