Posted 21 Dec 2010 02:06
Simply put: plastic and rubber is the most essential difference between the plastic deformation when plastic deformation occurs, while the rubber is elastic deformation. In other words, plastic deformation is not easy to restore the original state, while the rubber, relatively speaking, much easier. Flexible plastic is very small, usually less than 100%, while the rubber up to 1000% or more. Plastic molding process in forming the vast majority of finished product will end the process; and after the molding process of rubber vulcanization process have needed. Plastics and rubber belong to polymer materials, mainly carbon and hydrogen atoms, while some contain small amounts of oxygen, nitrogen, chlorine, silicon, fluorine, sulfur atom, the performance of special use is also special. At room temperature, plastic is solid, very hard, not tensile deformation. and rubber hardness is not high, elastic, can stretch longer, stop stretching can be reinstated. This is because they are caused by different molecular structure. The other difference recycled plastic can be reused many times, but can not be directly recycled rubber, recycled rubber can only be made into, and then be available. plastics in more than 100 degrees to 200 degrees and rubber in the form of 60 to 100, the degree of similar shape. plastic does not include the rubber. complex, said: Broadly speaking, the rubber is actually a kind of plastic, plastic, including rubber. Is one of detail, the formation of gum: gum natural rubber, respectively, and synthetic rubber for the two categories: 1. Natural rubber: rubber tree cut from the mouth of the outflow of mortar collected through to the impurities, freezing, smoking smoked, dried, and other processing procedures, and the formation of the raw rubber material. 2. Synthetic Rubber: A byproduct of the petrochemical industry, according to different needs, different physical properties of synthetic raw rubber material. Commonly used, such as: SBR, NBR, EPDM, BR, IIR, CR, Q, FKM and so on. But the difference synthesis methods, the same compound could be divided into several different raw rubber, also set by formula, any type of plastic material, can change into a thousand kinds of products meet the needs of the raw rubber material. Natural rubber from rubber trees in tropical and subtropical. The rubber in industry, agriculture, national defense, has an important role in the field, so it is an important strategic materials, which led first to the lack of rubber research and development resources of national synthetic rubber. Second, the chemical composition of rubber, natural rubber by the chemical composition analysis, found that its basic composition is isoprene. So inspired by people with isoprene as the monomer polymerization reaction, and synthetic rubber, known as isoprene rubber. Isoprene rubber in the structure and properties of natural rubber is basically the same. Since isoprene was obtained only from the turpentine, limited sources of raw materials, while the butadiene is a rich source, and therefore developed a series of butadiene-based synthetic rubber. Such as butadiene rubber, styrene butadiene rubber, nitrile rubber and chloroprene rubber. With the development of the petrochemical industry, from oil gas, refinery gas by pyrolysis and separation and purification, can be ethylene, propylene, butylene, isobutene, butane, pentene, prenyl, and other gases, which are manufactured good synthetic rubber raw materials. World rubber production, the natural rubber accounted for only about 15%, the rest are synthetic rubber. Many varieties of synthetic rubber, performance varied, in many cases can replace or even more than natural rubber. Rubber, synthetic rubber can be divided into general and special rubber. Larger amount of general purpose rubber, synthetic rubber such as styrene-butadiene rubber production accounted for 60%; followed by butadiene rubber, 15%; in addition to isoprene rubber, neoprene, Buna, ethylene-propylene rubber, butyl rubber so, they are of general rubber. Third, the rubber raw material preparation: preparation of rubber materials can be divided into three basic processes: 1. Plasticating: plastic practice is to cut raw rubber and raw rubber to plastics, homogenization, mixing agent to help with the job. The effect is to improve the dispersion of drugs to prevent the friction heat generated in operation that may cause rubber scorch phenomenon occurs, and then change the processing of rubber. 2. Mixing: mixing drugs is evenly mixed with the completion of the raw rubber plastic mixing, while mixing the merits, whether good products directly affected. Uneven spread of ****, molecular structure can not fully cross-linked rubber can not achieve the desired properties. 3. Extrusion: mixing the raw rubber to complete, after pressing out the operation, the rubber compound containing the excess air pressure out and complete the required thickness, in order to facilitate the mold of the molding operation. Fourth, rubber molding: raw rubber molecular structure of unsaturated elastomer long bond, so forming the elements, the need for appropriate **** additives and external environmental factors (such as time, temperature, pressure, etc.), it is not saturated bond destruction, re-combination of unsaturated bonds, and vacuum-assisted, the extract containing the air completely. So, in order to make the rubber molding to play its proper characteristics. If there is any lack of the molding process (such as **** errors, lack of time, temperature, misconduct, etc.), can result in loss of properties, the excess of **** release, deformation, accelerated aging, all serious adverse phenomenon. Fifth, the aging of rubber: rubber products according to the environmental conditions in which, with the lapse of time, causing cracking or hardening, degradation of physical phenomena such as rubber, known as aging. Caused by aging causes, external factors and internal factors: 1. External factors: External factors oxygen, oxides, ozone, heat, light, radiation, mechanical fatigue, lack of processing and so on.