Vulcanized rubber refers to vulcanized rubber, has the same viscosity, not easy to break and other characteristics, high temperature resistant silicone strip products are mostly made of this rubber. The vulcanized rubber has a three-dimensional structure and has high elasticity, heat resistance, tensile strength and insolubility in organic solvents.
The factors of vulcanization are mainly as follows. Vulcanization temperature of rubber vulcanization temperature is the most basic condition of vulcanization reaction of rubber, rubber vulcanization speed and the quality of products has a direct impact. The vulcanization reaction of rubber is accelerated as the temperature rises. If the temperature is 10℃, the vulcanization time of the plate vulcanizing machine is shortened by about half. Because rubber is a poor thermal conductor, the vulcanization process of the product varies with the temperature of its various parts. In order to ensure a more uniform degree of vulcanization, thick rubber products generally adopt gradual heating, low temperature and long time vulcanization. With the increase of room temperature vulcanization compound and the appearance of high temperature vulcanization, vulcanization temperature tends to two extremes. In terms of improving vulcanization efficiency, it should be considered that the higher the vulcanization temperature is, the better, but in fact, the vulcanization temperature cannot be increased wirelessly. Rubber is a high polymer, high temperature will make the molecular chain of rubber cracking reaction, leading to the fracture of crosslinking bonds, that is, the phenomenon of "vulcanization back", so that the physical and mechanical properties of vulcanized rubber decline. Rubber vulcanization time is an important part of the vulcanization process. Too short time, insufficient curing degree. Too much time, too much vulcanization. Plate vulcanizing machine only the appropriate degree of vulcanization, to ensure the best comprehensive performance. Under a certain temperature, molding, in order to make the rubber material from plastic to elastic, and achieve the maximum crosslinking density, the time used for the optimization of physical and mechanical properties is called the vulcanization time of rubber products. Rubber vulcanization time and rubber vulcanization temperature is closely related, in the process of vulcanization, the physical and mechanical properties of vulcanization rubber reach or close to the optimal point, the degree of vulcanization is called positive vulcanization or the most suitable vulcanization. The vulcanization time is called the vulcanization time. A certain vulcanization temperature corresponds to a certain vulcanization time. Rubber vulcanization pressure rubber vulcanization pressure refers to the pressure on the unit area of rubber vulcanization process. Rubber vulcanization pressure is an important factor to ensure the structural density, geometric size and physical machinery of rubber parts, but also to ensure the smooth surface of parts without defects, to achieve the sealing effect of rubber products.
The following five points are the principle of rubber vulcanization pressure selection: (1) rubber hardness is low, the pressure should choose small, high hardness should choose large; (2) simple structure, small selection, product structure complex selection; (3) thin products choose small, thick products choose large; ④ When the vulcanization temperature is higher, the pressure can be smaller, and when the temperature is lower, the pressure should be higher; (5) mechanical properties require low selection, high selection.