The process of curing rubber seal
Rubber molecules under heating and crosslinking agent sulfur attack chemical reaction and crosslinked to form three-dimensional network structure in the process. After the vulcanized called vulcanizated rubber. Vulcanization is rubber processing in the final process to finalize the design with practical value of rubber seal. In the reticular structure of the rubber, sulfur crosslink bonds (during which the sulfur atom number n is more than or equal to 1; and not crosslinke by sulfu atoms SX and SY) density determines the rubber sealing piece the vulcanization degree. The latter in technical practice is sizing microscopic physical machinery function or rubber viscosity change to determine the.
"Curing" word has its historic, because the beginning of natural rubber sealing parts with sulfur as crosslinking agent, the crosslinking named, along with the development of rubber industry, now can use a variety of non-sulfur crosslinking agent for crosslinking. Therefore vulcanized more scientific meaning should be "crosslinking" or "bridging", namely linear polymer by crosslinking effect and a polymer mesh technology process. Accessory is the plastic rubber into the process of elastic rubber or hard rubber. The meaning of "curing" includes not only practice crosslinking process, also includes crosslinking occurs between the way.
Rubber seal is formed first vulcanization process, the main factors influencing the vulcanization process is sulfur dosage, curing temperature and curing time. The amount of sulfur. The more the amount of sulfide, faster curing degree can reach the higher solubility of sulfur in rubber is limited, excessive sulfur will appearance precipitated by glue, commonly known as "spray sulfur." in order to reduce the sulfur spray appearance, demand at temperatures as low as possible, or at least below the melting point of sulfur  . On the basis of rubber seals use demand, amount of sulfur in the soft rubber usually does not exceed 3%, the amount of semi hard rubber is usually about 20%, in hard rubber vulcanization conditions in the amount of curing conditions can be as high as 40%. The curing temperature. If the temperature is 10 DEG C higher, vulcanization time is about half shortened. Because the rubber is poor conductors, rubber seal vulcanization process for The difference between the temperature of each part and not the same. In order to ensure uniform contrast the vulcanization degree, thick rubber product usually choose gradually warming, low-temperature curing a long time. The curing time. This is the important link of the vulcanization technology. Time is too short, the vulcanization degree insufficient (also known as less sulfur). Time is too longer, the vulcanization degree is too high (commonly known as sulfur). As long as suitable vulcanization degree (commonly known as vulcanization), ability ensures the best comprehensive function.

It can be divided into four periods, each with characteristics.
After the glue material tensile strength (or sulfide analyzer) measurement can be seen, the curing process can be divided into sulfide induced, pre sulfur, vulcanization and sulfur (for natural rubber is vulcanized back to the original four period.

   Curing induction period (char burn time), the crosslinking has not yet started, the gel has excellent mobility.During this period, the security of the coke and the process of the adhesive was decided. The end of the period, the rubber material began to cross link and loss of mobility.Curing induction period length except with the rubber vulcanization rubber molecules change figure vulcanized rubber molecules change figure body is related to the nature, depends on the additives used, such as delayed accelerant can get longer scorch time, and has high processing safety.

   Induction period of cure in the future is the crosslinking precured period to a certain speed. Pre vulcanization crosslink degree is low, even late vulcanizate tensile strength, elasticity is not arrived at the expected level, but dynamic tearing and tear but than the corresponding vulcanization.

   Arrived during vulcanization, the physical function of the separation of vulcanizates arriving at or near the best point, or arrive at the function of the composite balance.