The rubber produced by natural rubber factory is briefly introduced. Commercial natural rubber is mainly made of latex of rubber tree with three leaves. Composition There are about 2000 different plants in the world that can produce polymers similar to natural rubber, and 500 of them have obtained different kinds of rubber, but the real practical one is rubber tree with three leaves. When the surface of the rubber tree is cut, the milk duct in the bark is cut off and the milk flows out of the tree. The latex collected from rubber trees is diluted, acid cured, washed, tabletted, dried and packaged to obtain natural rubber on the market. According to the different methods of making rubber, natural rubber can be made into cigarettes, air-dried films, crepes, industrial rubber and concentrated rubber. Standard rubber or granular rubber is a new type of natural rubber developed in 1960s. In the past, general traditional products, such as cigarette flakes, crepe flakes and air-dried flakes, hindered the development of natural rubber in classification methods and manufacturing methods. Therefore, Malaysia began to implement the standard rubber plan in 1965, and developed the production of granular rubber based on the classification of physical and chemical properties of raw rubber. Standard rubber refers to rubber classified according to mechanical impurities, plastic retention rate, initial plastic value, nitrogen content, ash, ash and color index. The standard rubber packaging is also relatively advanced, generally packed with polyethylene film and clearly marked. The bag is light in weight and easy to move. The packing weight in Malaysia is 33.3kg, and that in China is 40kg. The classification of standard rubber is more scientific, so this classification method was quickly accepted by major natural rubber producing countries and international standardization organizations, and the classification standards of standard rubber were formulated one after another. These standards are roughly the same, but they are not completely consistent. For example, ISO2000 stipulates five grades, while our national standard GB 808 1-87 stipulates four grades. Natural Properties The natural rubber we usually refer to refers to the natural latex collected from Brazilian rubber trees, which is made into an elastic solid through solidification, drying and other processing procedures. Natural rubber is a kind of natural polymer compound with polyisoprene as the main component, and its molecular formula is (C5H8) N. Its rubber hydrocarbon (polyisoprene) content is above 90%, and it also contains a small amount of protein, fatty acid, sugar and ash. Physical properties of natural rubber. Natural rubber has high elasticity at room temperature, slightly plasticity, very good mechanical strength, low hysteresis loss and low calorific value during repeated deformation, so its bending flexibility is also good, and because it is nonpolar rubber, its electrical insulation performance is good. Chemical characteristics of natural rubber. Because of unsaturated double bonds, natural rubber is a substance with strong chemical reaction ability. Light, heat, ozone, radiation, bending deformation, copper, manganese and other metals can promote the aging of natural rubber. Aging resistance is the fatal weakness of natural rubber. However, natural rubber with antioxidants can still be used as usual after being exposed to the sun for two months. Medium resistance of natural rubber. Natural rubber has good alkali resistance, but it is not resistant to strong acid. Because natural rubber is nonpolar rubber, it can only resist some polar solvents, but it will swell in nonpolar solvents, so its oil resistance and solvent resistance are very poor. Generally speaking, hydrocarbons, halogenated hydrocarbons, carbon disulfide, ethers, higher ketones and higher fatty acids can dissolve natural rubber, but their solubility is affected by the degree of plasticization, while lower ketones, lower esters and alcohols are non-solvents of natural rubber. Variety classification and quality standard Natural rubber can be divided into two categories according to its morphology: solid natural rubber (film and granular rubber) and concentrated latex. In daily use, solid natural rubber accounts for the vast majority. According to the different manufacturing processes and shapes, films can be divided into cigarette glue, air-dried film, white wrinkled film and brown wrinkled film. Tobacco flake adhesive is the most representative variety of natural rubber, and it has always been a kind of adhesive with large dosage and wide application. Tobacco flake adhesive is generally classified according to appearance, which is divided into six grades: super grade, first grade, second grade, third grade, fourth grade and fifth grade. * * *, those that fail to reach Grade 5 are classified as external glue. Granular rubber (that is, standard rubber) is classified according to internationally unified physical and chemical properties and indicators. These physical and chemical properties include impurity content, initial plastic value, plastic retention rate, nitrogen content, volatile content, ash content and color index. Among them, the impurity content is the leading index, which is divided into five grades: 5L, 5, 10, 20 and 50. The contract delivery grades of natural rubber in Shanghai Futures Exchange, China's futures trading market, are domestic first-class standard rubber SCR5 and imported tobacco flake rubber RSS3, among which domestic first-class standard rubber SCR5 is also commonly known as No.5 standard rubber, and all quality indexes of Natural Rubber GB/T 808 1 ~ 1999 issued and implemented by the State Bureau of Technical Supervision are implemented. Imported cigarette rubber RSS3 implements the International Standard for Grade Quality and Packaging of Natural Rubber (Green Paper) determined by the International Rubber Quality and Packaging Conference (version 1979). The main purpose of editing this paragraph is that natural rubber has the above-mentioned series of physical and chemical characteristics, especially its excellent resilience, insulation, water repellency and plasticity. After proper treatment, it also has valuable properties such as oil resistance, acid resistance, alkali resistance, heat resistance, cold resistance, pressure resistance and wear resistance, so it is widely used. For example, rain boots, warm water bags and elastic bands used in daily life; Surgical gloves, blood vessels and condoms used in the medical and health industry; All kinds of tires for transportation; Industrial conveyor belts, conveyor belts and acid alkali resistant gloves; Irrigation and drainage hoses and ammonia bags for agriculture; Sounding balloons for meteorological measurement; Sealed shockproof equipment for scientific experiments; Aircraft, tanks, cannons and gas masks for national defense; Even high-tech products such as rockets, artificial earth satellites and spaceships are inseparable from natural rubber. At present, there are more than 70,000 kinds of articles made of natural rubber partially or completely in the world. The history of natural rubber is 1492. Long before Columbus discovered America, local residents in Central and South America began to use it. 1736 It was not until 1736 that France first reported the origin of rubber, the method of collecting latex and the local utilization of rubber in South America, so that Europeans began to understand natural rubber and further studied its utilization value. After 1839, 100 years passed, until 1839, American C. Goodyear discovered that sulfur and basic lead carbonate were added to rubber. After being heated or exposed to the sun, rubber products are no longer as easy to soften and stick as before, but maintain good elasticity, thus inventing rubber vulcanization. 1888, an Englishman named J.B. Dunlop invented pneumatic tires, which promoted the rapid development of automobile tire industry, resulting in a sharp increase in rubber consumption. From 65438 to 0876, H.Wickham, an Englishman, collected rubber seeds from the mouth of Masson River in Brazil, transported them back to the Royal Botanical Garden for planting, and tried them in Ceylon (now Sri Lanka), Indonesia and Singapore, all of which were successful. This is the beginning of the settlement of Brazilian rubber trees in the Far East. Since then, the planting of rubber industry has developed very rapidly. 1997 The world output of natural rubber has reached 6.247 million tons. After the founding of New China, the scientific and technological workers of China Agricultural Reclamation broke the so-called 15 in foreign countries for a hundred years through scientific practice. To the north is the conclusion that the cultivation of rubber trees in Brazil is a "forbidden area", and it is successfully located at north latitude 18. 24 degrees north latitude. Hevea brasiliensis is planted in a large area in China with high yield. 1996 natural rubber production has reached 420,000 tons, making it the fifth largest natural rubber producer in the world. In 2007, the General Office of the State Council issued the Opinions on Promoting the Development of China's Natural Rubber Industry (Guo Ban Fa [2007] 10), which further clarified the strategic positioning of "Natural Rubber is an important strategic material and industrial raw material", affirmed the great contribution made by China's natural rubber industry, pointed out the existing problems and challenges in the development of China's natural rubber industry at present, and put forward the future development direction of China. The Opinions clearly state that by 20 15, the annual production capacity of natural rubber in China will reach more than 800,000 tons, and the overseas production and processing capacity will reach more than 600,000 tons. The Opinions clearly defined the direction for the rapid and healthy development of China's natural rubber industry, created a good environment and opened up a broad working space. This is an epoch-making programmatic document guiding the development of China's natural rubber industry in the new period, which has great practical significance and far-reaching historical significance. The characteristics and distribution of natural rubber rubber trees originated in the western part of Marayo, Brazil, and have now spread to more than 40 countries and regions in Asia, Africa, Oceania and Latin America. Countries with large planting areas include: Indonesia, Thailand, Malaysia, China, India, Viet Nam, Nigeria, Brazil, Sri Lanka and Liberia. Rubber planting areas in China are mainly distributed in Hainan, Guangdong, Guangxi, Fujian and Yunnan, and can also be planted in Taiwan Province Province, among which Hainan is the main rubber planting area. An evergreen tree with milky juice. The root system is straight, the compound leaves are trifoliate, and the leather is entire. Flowers unisexual, monoecious, panicle. The fruit is a capsule with oval seeds. Rubber tree in Brazil has great variability and adaptability. The annual average temperature is 26 ~ 27℃, and there is no absolute minimum temperature below15℃. The annual rainfall is more than 2500mm, which is evenly distributed; The annual average relative humidity is above 80%; The soil depth is above 1m, the surface layer is 20 ~ 30cm, the organic matter content is above 3%, and the soil pH value is 5 ~ 6. The soil quality is loam, and the groundwater level is more than 1.5 ~ 2m. The altitude is generally below 300 m, and it is planted in areas where there is no strong wind.