At present, the production method of the O-shaped rubbe […]
At present, the production method of the O-shaped rubber sealing ring is mainly mainly produced by the molding method, and the vulcanization methods of the molded product mainly include three types of flat molding, transfer molding and injection molding. The flat molding method has the longest history. Transfer molding began to be used around the 1950s, and the injection molding pressure gradually entered the rubber industry from the plastics industry since the 1960s. The current development trend is to gradually develop the injection method, but the scope of each adaptation is different. It is still a reality that the three will coexist and gain development. Rubber o ring are still mainly molded by flat plate molding according to their characteristics.
In the process of molding vulcanization, the temperature, time and pressure of vulcanization must be strictly and correctly controlled, and the changes of parameters such as temperature during vulcanization should be paid attention to and treated accordingly, otherwise the product will be sulphur or supersulfur. If an automatic control system is used, the entire vulcanization process is automatically recorded and controlled to ensure that the product is positively vulcanized.
The vulcanization temperature is one of the basic conditions for the vulcanization reaction of the rubber O-ring, which directly affects the vulcanization speed and product quality. High vulcanization temperature, fast vulcanization rate, high production efficiency; low vulcanization temperature and slow vulcanization rate. The vulcanization temperature depends on the formulation, the most important of which depends on the gum grade and the vulcanization system used. The most suitable vulcanization temperature of natural rubber is generally 143 ° C - 150 ° C, and the synthetic rubber is generally 150 ° C ~ 180 ° C. The vulcanization time is usually determined by testing according to the determined vulcanization temperature.
The rubber product is pressurized during the vulcanization process, and the purpose is to make the rubber material flow easily, fill the cavity, prevent bubbles from being generated during the vulcanization process, and improve the compactness of the product. The size of the vulcanization pressure depends on the hardness of the compound and the size of the mold. When the hardness of the rubber is high and the mold size is large, the pressure may be larger, and vice versa, the pressure should be appropriately reduced.