First, the basic process
There are many kinds of rubber products, but the production process is basically the same. The basic process of rubber products using general solid rubber-raw rubber as raw materials includes six basic processes of mastication, mixing, calendering, extrusion, molding and vulcanization. Of course, basic processes such as raw material preparation, finished product finishing, and inspection and packaging are also indispensable. The rubber processing process is mainly to solve the contradiction process of plasticity and elastic properties. Through various processes, the elastic rubber is transformed into a plasticized plastic compound, and then various compounding agents are added to make a semi-finished product, and then the semi-finished product having plasticity is turned into a rubber product with high elasticity and good physical and mechanical properties by vulcanization. .
Second, raw material preparation
1. The main raw material of rubber products is raw rubber, which is grown in the tropics. The subtropical rubber trees are collected by artificially cutting the bark.
2. Various compounding agents are auxiliary materials added to improve certain properties of rubber products.
3. Fiber materials (cotton, hemp, wool and various rayon, synthetic fiber and metal materials, steel wire) are used as the skeleton material of rubber products to enhance mechanical strength and limit product modification. In the raw material preparation process, the ingredients must be weighed accurately according to the formula. In order to allow the raw rubber and the compounding agent to be uniformly mixed with each other, the material needs to be processed. The raw rubber should be softened in a 60--70 ° C drying room, then cut into pieces, broken into small pieces, and the compounding agent has a block shape. Such as paraffin, stearic acid, rosin, etc. to be crushed. If powdery contains mechanical impurities or coarse particles, it is necessary to screen and remove liquid such as pine tar. Gumaron needs heating, melting, evaporating water, and filtering impurities. If the compounding agent is to be dried, it will be easy to agglomerate and if it is not dispersed during mixing. Air bubbles generated during uniform vulcanization can affect product quality.
Raw rubber is elastic and lacks the plasticity properties necessary for processing, so it is not easy to process. In order to improve the plasticity, the raw rubber is masticated, so that the compounding agent is easily dispersed uniformly in the raw rubber during the kneading, and also helps to improve the permeability of the rubber into the fiber fabric during the calendering and molding process. And molding fluidity. The process of degrading the long-chain molecules of raw rubber to form plasticity is called mastication. There are two kinds of raw plastic mastication methods: mechanical mastication and thermoplastic refining. Mechanical mastication is a process in which the degradation of long-chain rubber molecules is shortened from a highly elastic state to a plastic state by mechanical extrusion and friction of a plasticizer at a relatively low temperature. Thermoplasticing is the introduction of hot compressed air into the raw rubber to shorten the degradation of long-chain molecules under heat and oxygen to obtain plasticity.