Rubber products in the heavy metal content is not only from one or two key raw materials, is all the raw materials (including raw rubber) heavy metal content of the sum. Some raw materials, although very heavy metal content (such as white carbon and kaolin), but also pay attention to "accumulate."
Rubber products in the vulcanization, the rubber is vulcanized rubber products often appear when the quality defects, not only affect the appearance of the product quality, and even affect the inherent quality of the product. Through the observation and analysis of the scene on the causes of the bubble generation, developed a solution to the problem, to minimize the occurrence of bubble phenomenon, improve the appearance of the product quality.
Rubber products vulcanized product bubbles are many factors, the key reasons are raw materials, compound mixing processing, process operation, curing equipment and mold and other factors.
The main materials of rubber products are raw rubber, with agents, fiber materials and metal materials. (Cotton, hemp, wool and all kinds of man-made fibers, synthetic fibers) and metal materials (steel wire, copper wire), and the material is used as the base material; Is used as a skeleton material for rubber products to enhance mechanical strength and restrict product variants.
During the preparation of the raw material, the ingredients must be accurately weighed according to the formula. In order to make the raw gum and the compounding agent can be mixed with each other, some materials need to be processed:
Raw rubber to cut rubber, broken into small pieces;
Such as paraffin, stearic acid, rosin, etc. to be crushed;
Powder containing agent containing mechanical impurities or coarse particles need to be removed;
Liquid compounding agent (pine tar, ancient malon) need to heat, melt, evaporate moisture, filter impurities;
Matching agent to be dry, or easy to agglomerate, mixing the old can not be dispersed evenly, when the vulcanization of bubbles, thus affecting product quality;
Raw rubber is flexible, lacks the necessary performance (plasticity) during processing, and therefore is not easy to process. In order to improve its plasticity, it is necessary to plasticize the raw rubber; so that when the mixing agent is easy to evenly dispersed in the raw rubber; at the same time, in the rolling, molding process also helps to improve the permeability of the compound (infiltration Fiber fabric) and molding fluidity. The long-chain molecules of raw rubber degradation, the formation of plasticity process called mastication. There are two kinds of plastic molding and thermoplastic mixing. Mechanical plasticization is at a very high temperature, through the plastic mill mechanical squeeze and the role of friction, so that long-chain rubber molecules become shortened, from high elastic state into a plastic state. Thermoplastic refining is to the raw rubber into the hot compressed air, under the action of heat and oxygen, so that long-term degradation of the long chain molecules, resulting in plasticity.
In order to adapt to a variety of different conditions of use, to obtain a variety of different performance, but also to improve the performance of rubber products and reduce costs, must be added in the raw rubber with a different agent. Mixing is the plastic blend of raw rubber and mix agent, placed in the mixing machine, through the mechanical mixing, so that with the agent completely and evenly dispersed in the raw rubber in a process. Mixing is the rubber products in the production process of an important process, if the mixing is not uniform, can not give full play to the role of rubber and mix agent, affecting the use of products performance. The compound obtained after mixing is known as a compound, which is a semi-finished material for the manufacture of various rubber products, commonly known as a compound, which is usually sold as a commodity. The purchaser can use the compound to be directly processed and vulcanized Need for rubber products. Depending on the formulation, the blend has a range of different grades and varieties offering different options.