Answer: time, temperature, pressure, shape, weight, speed

What is the relationship between the six factors of vulcanization?

1. Molding temperature: when the formula is fixed, the temperature is the basis for curing. If the temperature is not enough, the rubber will not react. If the temperature is too high, the product will be brittle and deformed. Generally, the silica gel is lower than 170 ℃, the curing speed is slow, and the time must be extended; When the temperature is higher than 180 ℃, the vulcanization speed is very fast and the output is high, but it is easy to get dirty and shiny, the product is deformed, the size becomes smaller, the thinning thickness exceeds the standard, and the burr is brittle.

2. Vulcanization time: the length of vulcanization time directly affects the quality of products. The vulcanization time is short, the product is not ripe, the deformation is large, it is easy to turn white, and the product is not durable; If the time is too long, the product will produce excessive sulfur, and the strength and hardness will become worse, resulting in brittle or sticky surface; The relationship between temperature and time must be formulated according to the thickness and glue type of the product; Thick products must be vulcanized at low temperature for a long time; If it is found that the time is not enough after the mold is pulled out, the product is not mature and stuck on the mold, and it is difficult to clean the mold by digging and washing, the mold should be closed again and vulcanized, and the material can be stuck down basically. One of the biggest problems in molding is the waste products caused by employees' private adjustment of machines.

3. Machine pressure: refers to the set pressure of the molding vulcanizer, which is controlled by pressure gauge and computer. Sufficient pressure can allow the rubber to be completely pressed into the mold when the mold is closed, and prevent bubbles due to trace moisture generated by the rubber during vulcanization. The product bubbles can be controlled with exhaust. The rubber has high hardness and poor fluidity, so the selection pressure should be large; Too high pressure, easy to crush the die blade; The pressure is related to the overall dimension of the die. If the die is small, the pressure should be reduced accordingly to prevent the deformation of the die and vulcanizer plate. When adjusting the pressure of the vulcanizer, the maximum pressure shall not exceed the maximum pressure of the vulcanizer, otherwise the machine may be damaged. Non pressurization of empty mold (except injection mold) is an effective measure to protect the knife edge of mold and prolong the service life of mold.

4. Rubber shape: refers to the preformed shape of rubber, which can be a long strip, a small square or a circle. The thickness, length and width of the rubber must be close to the product. The closer the rubber shape is to the product shape, the shorter the rubber flow time in the mold, the shorter the flow distance, the thinner the burr, the less the amount of rubber used, and the higher the qualification rate of the product;

5. Rubber weight: the weight of rubber must be greater than the weight of the product, otherwise it will be short of rubber. However, the more rubber is placed, the thicker the burr of the product will be and the larger the size will be. The weight of the compound is directly related to the shape of the compound. How to use the least glue and produce with the most reasonable shape without lack of glue is the embodiment of the technical level of molding employees. The weight of the compound is enough, but the length is longer than the mold, and there will be lack of glue; The shape and weight of the compound are appropriate, but if it is placed too far, it will be thin at one side and thick at the other side. In serious cases, it will be short of glue and thick at the same time. The shape and total weight of the rubber material are appropriate, but the thickness and width of the shear are uneven, or the rubber supplement is uneven, which will also cause glue shortage. When the product is short of glue, don't worry about adding glue. First take the complete mold containing burr, check the weight, then see whether the thickness of the product is uniform, and finally decide whether to add material. The technical content and experience of the molding foreman are very important.

6. Operating speed: refers to the operating speed of sulfur chemical industry when putting glue and taking products. Rubber vulcanization the chemical reaction. The first mock exam will start to vulcanizing the rubber from the mold. The first time the glue is put on the last piece of glue, the shorter the time to put the glue. The glue should be immediately moulded, otherwise it will be dirty, the rubber is blanching, the edges are thick and the deformation is abnormal. When taking the product, it is easy to blow out the product with pneumatic assistance, but it will reduce the temperature of the mold. If you are not skilled in operation, it is most likely that the mold temperature is getting lower and lower, resulting in unfamiliar products and sticking molds. Novices are most likely to have this problem. In the production of smooth rubber plate, the speed of glue swing, mold closing and mold opening has the most obvious impact on the smooth quality. Why some products with strict appearance requirements choose to hang the mold for operation, one of the main principles is also here!