Study On Uniform Curing Mechanism And Equipment Of Thick Rubber Products With The Method Of Electromagnetic Induction Pulse Heating

Vulcanization is one of the main technology of rubber processing, to improve the physical and mechanical properties of rubber and other performance, and make products better able to adapt and satisfy the use of requirement is very important. And curing pressure, temperature and time are the main factors constituting the vulcanization process conditions, which have a decisive impact on the quality of vulcanization, commonly referred to as "vulcanization three elements", reasonable regulation and control of curing pressure, temperature and time to improve the quality of vulcanization and then enhance the comprehensive performance of rubber is essential. The whole process of rubber vulcanization can be divided into four stages:charred, heat curing, vulcanization and over-vulcanization. Charred phase refers to the mixing, thermal refining, rubber molding process and the movement of the rubber mold heating. Vulcanization broad sense beginning from heat curing, heat curing stage requires a sharp rise in the temperature of vulcanization, at this stage, at this stage, the tensile strength increased quickly, then the thermal curing temperature reaches a certain value, vulcanization process into is vulcanization phase, which is also called flat vulcanizing stage, rubber vulcanization net structure tend to be more complete, crosslinking reaction tends to be slow, maximum strength and constant. Normal curing should be at the end of this stage within the appropriate time, to ensure the high performance of rubber products, if continue to vulcanization into over-vulcanization phase, namely this stage rubber network structure cracking becomes significant, product strength decline. The optimum state of rubber vulcanization is equal to the partial curing effect of the products, and the products with similar physical properties and uniform curing degree are obtained; in fact, the rubber is a poor conductor of heat, while achieving the vulcanization of each part is difficult, especially for thick wall products, when the center of the thick wall products just in vulcanization, the face of the rubber has been injured in even serious over-vulcanization, the overall performance of products suffered severe damage. For thick wall-products current vulcanization process, often in the coordination of different parts of work in process with different degree of wall thickness and the rubber with different curing speed, to adapt to the huge difference in internal and external temperature and degree of cure, or through the use of low temperature curing to reduce unevenly, but it would has a enormous influence on the rate of production.For thick-walled rubber products, the accurate choice of curing temperature and time is often more difficult, now most of the manufacturers methods is the use of vulcanizing temperature measuring instrument for each portion of products to determine the actual curing temperature, Then putting each part rubber through thermal process into semi-finished products under the isothermal curing of equivalent vulcanization time, in order to obtain the actual degree of cure of each part, then respectively comparing with using rubber semi-finished products which are in vulcanized state, according to the vulcanization overall matching state, and ultimately determine the vulcanization process conditions.Induction heating vulcanization technology of thick walled rubber products is the use of electromagnetic induction and electromagnetic heat conduction principle for thick walled rubber vulcanization heating, which using electromagnetic induction heating methods to make products vulcanization mold heating, through to rubber mold heat transfer, heat transmit by the rubber face for center portion. The induction heating is generated by electromagnetic induction in the conductor of the eddy current heating work products to achieve the electrical heating, it is depend on the sensor through the electromagnetic induction convey electricity to the heated metal, electrical energy changing into heat energy within the metal, achieve the purpose of heating metal. Electromagnetic induction heating is characterized by quick temperature rise, low power consumption, electromagnetic coil easy configuration, the electric parameters of hot convenient adjustment, etc. This paper intends to use the form of the pulse heating, intermittent heating apparatus for curing, so that heat the surface of the rubber have enough time to transfer to the central portion, to achieve a uniform vulcanization of rubber each part.Electromagnetic induction heating vulcanization technology of thick walled rubber product can reduce the products on the surface of over-vulcanization level, make the product vulcanization uniformity greatly improved, thus improve the performance of the articles. However, let it in the direction of center equivalent vulcanization, shorten the curing time of products, enhance the efficiency of the production of rubber products; On the basis of the characteristics of the pulse heating, the actual energy consumption greatly shorten the time, and significantly reduce energy consumption.