The Three Elements of Rubber Vulcanization

Vulcanized rubber refers to rubber that has been vulcanized and has characteristics such as no stickiness and resistance to breakage. Most rubber products are made from this type of rubber. After vulcanization, a three-dimensional structure is formed inside the rubber, which has high elasticity, heat resistance, tensile strength, and insolubility in organic solvents.

The main factors affecting rubber vulcanization are as follows: the temperature of rubber vulcanization is the most basic condition for rubber to undergo vulcanization reaction, which has a direct impact on the speed of rubber vulcanization and the quality of the product. The rubber vulcanization reaction accelerates with increasing temperature. If the temperature is 10 ℃ higher, the vulcanization time of the flat vulcanizing machine is reduced by about half. Due to the poor thermal conductivity of rubber, the vulcanization process of rubber products varies due to temperature differences in different parts. In order to ensure a relatively uniform degree of vulcanization, thick rubber products are generally vulcanized gradually at high temperatures and low temperatures for a long time. With the increase of room temperature vulcanized rubber and the emergence of high-temperature vulcanization, the vulcanization temperature tends towards two extremes. In terms of improving vulcanization efficiency, it should be considered that the higher the vulcanization temperature, the better, but in reality, the vulcanization temperature cannot be infinitely increased. Rubber is a high molecular weight polymer, and high temperatures can cause cracking reactions in the rubber molecular chains, leading to the breakage of cross-linking bonds, resulting in the phenomenon of "vulcanization returning to its original state", thereby reducing the physical and mechanical properties of vulcanized rubber. The vulcanization time of rubber is an important step in the vulcanization process. The time is too short and the degree of vulcanization is insufficient. Excessive time and high degree of vulcanization. Only with an appropriate degree of vulcanization can a flat vulcanizing machine ensure optimal comprehensive performance. The time required to optimize the physical and mechanical properties of rubber products at a certain temperature and during molding, in order to transform the rubber material from plasticity to elasticity and achieve maximum cross-linking density, is called the vulcanization time of rubber products.

The vulcanization time and temperature of rubber are closely related. During the vulcanization process, when the physical and mechanical properties of the vulcanized rubber reach or approach the optimal point, this degree of vulcanization is called positive vulcanization or optimal vulcanization. The vulcanization time required to achieve positive vulcanization is called positive vulcanization time, and a certain vulcanization temperature corresponds to a certain positive vulcanization time. The pressure of rubber vulcanization refers to the pressure per unit area that the rubber compound is subjected to during the vulcanization process. Rubber vulcanization pressure is an important factor in ensuring the structural density, geometric dimensions, and physical and mechanical properties of rubber parts, while also ensuring a smooth and defect free surface of the parts, achieving the sealing effect of rubber products.