Sulphur, a common mineral in nature, has a very important medicinal value. But in the eyes of the rubber man, sulfur yellow has a more important use than medicine - the vulcanizing agent in rubber products.

Sulfur is the most commonly used vulcanizing agent, vulcanizing agent is an essential rubber industry additives, its production and application level affects the development of rubber products and rubber processing industry, the current largest amount of vulcanizing agent is sulfur. With sulfur belongs to the same family of selenium and tellurium. There are two kinds of sulfur yellow: rhombic and amorphous (or insoluble sulfur yellow).

Rubber, an ancient material, was used by our ancestors at a very early stage, when it was mostly used only as an adhesive and to make waterproof clothing. Rubber has one fatal disadvantage: it is too sensitive to temperature. It becomes soft, sticky and smelly at higher temperatures, and brittle and hard at lower temperatures.

Traditional rubber to have excellent performance, it must be from the linear macromolecular chain through crosslinking to form a three-dimensional network space structure. The cross-linking process is often also referred to as vulcanization of rubber, simply because the initial cross-linking is achieved with sulfur. After vulcanization of rubber, as the structure changes, the performance also changes: rubber is no longer flowed by heat, no longer soluble in its good solvent, modulus and hardness increase, mechanical properties improve, aging resistance and chemical stability.

Rubber vulcanization process is the chemical reaction process of vulcanization, the complete vulcanization system consists of vulcanizing agent, active agent, accelerator three parts. The vulcanization of rubber is a multi-chemical reaction, including rubber molecules and the chemical reaction between the vulcanizing agent and other agents, but the reaction of sulfur yellow is the main one.

The vulcanizing agents used in the rubber industry are sulphur powder, insoluble sulphur, colloidal sulphur, precipitated sulphur, sublimated sulphur, deacidified sulphur and non-crystallized sulphur.

The amount of sulfur yellow in the rubber material should be based on the nature of the specific rubber products. Rubber products can be divided into three categories according to their nature: soft rubber (such as tires, hoses, tapes, rubber shoes, etc.); sulfur yellow dosage is generally 0.2-5.0 parts. Semi-hard rubber (such as rubber rollers, textile rollers, etc.); sulfur dosage is generally 8 to 10 parts. Hard rubber (such as battery shells, insulating rubber plates, etc.); sulfur dosage is generally 25-40 parts.