Rubber products

Rubber product refers to the activities of producing various rubber products with natural and synthetic rubber as raw material, including rubber products reproduced from waste rubber.

Basic characteristics of rubber products

1. When rubber products are formed, after large pressure pressing, the cohesive force of the elastomer cannot be eliminated. When forming from the mold, the shrinkage rate of rubber is often extremely unstable (the shrinkage rate of rubber is different because of different types of rubber). Therefore, when a rubber product design at the beginning, regardless of formula or mold, need to be carefully calculated and coordinated, if not, it is easy to produce product size instability, resulting in low product quality.

2. Rubber belongs to the elastomer of hot melt and thermosetting, and plastic belongs to the hot melt and cold solid. Rubber due to different types of sulfide main body, its molding curing temperature range, there is a considerable gap, even due to climate change, indoor temperature and humidity. Therefore, the production conditions of rubber finished products need to be adjusted moderately at any time, if not, it may produce the difference in product quality.

Sponge rubber products

Sponge rubber is a kind of porous elastomer material, usually known as foam rubber, foam rubber or microporous rubber, it is a general term for a variety of rubber with hole structure. ASTM D1055 and ASTM D1056 respectively define and classify latex sponge and dry glue sponge, and develop a method for the determination of routine physical properties. The standard definition of this kind of porous material hole should be in material as a whole, depending on the pore structure can be divided into obturator (without feeling) between the hole and the hole, hole (between hole and the hole is not completely separated by the hole wall, with a certain degree of connectivity) and mixed hole with two structures of bore (both open and closed) three. Accordingly, microporous rubber mainly includes expansion rubber and sponge rubber two types. Due to the different use habits, the meaning of "sponge rubber" in domestic scientific and technological literature does not distinguish the opening of the bubble hole and the obfuscator mechanism. There are many varieties of sponge rubber, and the classification methods are various: 1. The classification of foam mechanism: closed microporous rubber and open microporous rubber;

2, foaming rate classification: low foaming (apparent density ≥0.5g/ square cm) and high foaming (apparent density < 0.5g/ square cm);

3, rubber matrix classification: NR rubber, SBR rubber, DPDM rubber, NBR rubber, silicone rubber sponge, rubber sponge, rubber and plastic sponge, etc.;, performance and performance classification: soft sponge, hard sponge, microbubble sponge, conductive sponge, magnetic sponge, water expansion sponge, composite sponge, etc.

Compared with solid rubber, sponge rubber because of its structural particularity, that is, porosity, so that it has a lot of special valuable properties, such as :(1), small density, light material; (2), full of elasticity and softness, with excellent dustproof, waterproof gas sealing effect; (3), improve the heat insulation performance, with low thermal conductivity; (4) Improve the ability to absorb the impact load, has excellent damping performance; (5), improve the sound insulation, sound absorption effect; (6) Improve the tactility and comfort; (7) The range of physical properties is large, and the corresponding properties of sponge rubber can be obtained by changing the apparent density or the pore structure. Therefore, sponge rubber products are widely used in sealing, shock absorption, heat insulation, sound insulation, printing and dyeing and ion exchange, etc., in aviation, automobile, instrument, instrument, home appliances and packaging industry are playing a wide range of applications. Its shape is plate, strip, tube, roller, gasket, etc., various specifications, different shapes. Different use conditions require different hole structure and aperture size. Therefore, it is required to adjust the formula design and processing technology to achieve the corresponding performance

Classification of rubber products

Rubber is divided into natural rubber and synthetic rubber. Natural rubber mainly comes from three leaf rubber tree, when the skin of this rubber tree is cut open, it will flow out of milky juice, called latex, latex by condensation, washing, forming, drying natural rubber. Synthetic rubber is made by synthetic methods, using different raw materials (monomers) can be synthesized into different kinds of rubber. Such as butadiene rubber, neoprene rubber, styrene butadiene rubber and so on. The yield of synthetic rubber has greatly exceeded that of natural rubber, among which the largest yield is styrene-butadiene rubber.

General rubber

Refers to part or all of the rubber used to replace natural rubber, such as styrene-butadiene rubber, butadiene rubber, isoprene rubber, mainly used in the manufacture of tires and general industrial rubber products. General rubber demand is large, is the main synthetic rubber varieties.

Styrene butadiene rubber

Styrene-butadiene rubber [1] is made from the copolymerization of butadiene and styrene, is the largest yield of general synthetic rubber, latex polystyrene butadiene rubber, dissolved polystyrene butadiene rubber and thermoplastic rubber (SBS).

Butadiene rubber

Butadiene is prepared by solution polymerization, butadiene rubber has particularly excellent cold resistance, wear resistance and elasticity, but also has good aging resistance. Butadiene rubber is mostly used in the production of tires, a small part of the manufacturing cold-resistant products, cushioning materials and tape, rubber shoes, etc. Butadiene rubber has the disadvantage of poor tear resistance and poor wet slip resistance.

Isoamyl rubber

Isoprene rubber, short for polyisoprene rubber, is produced by solution polymerization. Isoprene rubber, like natural rubber, has good elasticity and wear resistance, excellent heat resistance and good chemical stability. The strength of raw isoprene rubber (before processing) is significantly lower than that of natural rubber, but its quality uniformity and processing performance are better than that of natural rubber. Isoprene rubber can replace natural rubber to make truck tires and off-road tires can also be used to produce a variety of rubber products.

Ethylene propylene rubber

Ethylene propylene rubber with ethylene and propylene as the main raw materials synthesis, aging resistance, electrical insulation and ozone resistance performance. Ethylene propylene rubber can be filled with oil and filled with carbon black, the price of products is low, ethylene propylene rubber chemical stability is good, wear resistance, elasticity, oil resistance and styrene butadiene rubber close. Ethylene propylene rubber has a wide range of uses. It can be used as tire side, rubber strip and inner tube as well as auto parts. It can also be used as wire and cable covering and high voltage and super high voltage insulation material. Can also manufacture rubber shoes, sanitary products and other light - colored products.

neoprene

It is chloroprene as the main raw material, through homopolymerization or a small amount of other monomer copolymerization. Such as high tensile strength, heat resistance, light resistance, aging resistance, oil resistance are better than natural rubber, styrene butadiene rubber, butadiene rubber. It has strong fire resistance and excellent flame resistance, high chemical stability and good water resistance. The disadvantages of neoprene rubber are electrical insulation performance, cold resistance performance is poor, raw rubber is unstable in storage. Neoprene is used in a wide range of applications, such as transportation belts and transmission belts, the wrapping material for wires and cables, the manufacture of oil-resistant hoses, gaskets and chemical resistant equipment linings.

Rubber products material structure composition

Linear structure: a common structure for unvulcanized rubber. Due to the large molecular weight, no external force, a fine cluster. When the external force acts, remove the external force, the entanglement of the fine group changes, the molecular chain rebounds, producing a strong tendency to recover, which is the origin of high elasticity of rubber.

Branched chain structure: Aggregation of branched chains of rubber macromolecular chains to form a gel. Gelation is detrimental to the properties and processing of rubber. In rubber refining, various additives often improve the gel area, forming a local blank, can not form reinforcing and cross-linking, become the weak part of the product.

Crosslinking: Linear molecules linked to each other by bridging atoms or groups to form a three-dimensional network. With the process of curing, the structure is strengthened. In this way, the free movement of the chain segment decreases, the plasticity and elongation decrease, the strength, elasticity and hardness increase, and the permanent deformation and swelling degree of compression decrease.

The advantages and disadvantages and uses of different kinds of rubber materials

Natural rubber NR

Natural Rubber is made from latex collected from Rubber trees and is a polymer of isoprene. Good wear resistance, high elasticity, tensile strength and elongation. It is easy to age in air, and become sticky when heated. It is easy to expand and dissolve in mineral oil or gasoline. It is resistant to alkali but not strong acid. Advantages: Good elasticity, acid and alkali resistance. Disadvantages: not weather resistant, not resistant to oil (resistant vegetable oil) is the production of tape, hose, rubber shoes of raw materials, and suitable for the production of shock parts, in the automobile brake oil, ethanol and other products with hydroxide liquid used.

Styrene butadiene rubber SBR

The Styrene Butadiene Copolymer has more uniform quality, less foreign body, better wear resistance and aging resistance than the natural rubber, but its mechanical strength is weak, so it can be mixed with the natural rubber. Advantages: low cost non-oil resistant material, good water resistance, hardness below 70 with good elasticity, high hardness with poor compressibility, disadvantages: not recommended to use strong acid, ozone, oil, oil ester and fat and most hydrocarbons. Widely used in tire industry, footwear industry, cloth industry and conveyor belt industry.

Butyl rubber IIR

The Butyl Rubber is formed by polymerization of isobutylene and a small amount of isoprene, because the movement of methyl stereo obstacle molecules is less than other polymers, so the gas transmission is less, the resistance to heat, sunlight, ozone, electrical insulation is good; High resistance to polar capacitors, generally used in the temperature range of -54-110 ℃. Advantages: impermeable to most general gases, good resistance to sunlight and odors, can be exposed to animals or vegetable oils or gasizable chemicals. Disadvantages: It is not recommended to use the inner tube, leather bag, rubber paste paper, window frame rubber, steam hose, heat-resistant conveyor belt of automobile tires at the same time with petroleum solvent, rubber kerosene and aromatic hydrogen

Hydrogenated butadiene HNBR

Hydrogenate Nitrile is used to remove part of the double chain after hydrogenation. After hydrogenation, its temperature resistance and weather resistance are much higher than that of general Nitrile, and its oil resistance is similar to that of general Nitrile. The general operating temperature range is -25~150 ℃. Advantages: compared with butane rubber has better wear resistance, excellent corrosion resistance, tensile resistance, tear resistance and compressibility characteristics

Good resistance to ozone and other atmospheric conditions, generally used in laundry or dishwashing detergent. Disadvantages: it is not recommended to be used in alcohols, esters or aromatic solutions in air-conditioning refrigeration industry, widely used in environmental protection refrigerant R134a system seals.

Automotive engine system seals.

Ethylene propylene Rubber (EPDM) is made from Ethylene and propylene copolymer, so it has excellent heat resistance, aging resistance, ozone resistance and stability, but sulfur and sulfur cannot be added. In order to solve this problem, a small amount of the third component with double chain can be imported into the EP main chain and sulfur can be added to form EPDM, the general operating temperature is -50~150 ℃. Excellent resistance to polar solvents such as alcohol, ketone and other advantages: good weather resistance and ozone resistance, excellent water resistance and resistance to chemicals, alcohols and ketones can be used, high temperature vapor resistance, good permeability to gas. Disadvantages: Not recommended for food use or exposure to aromatic hydrogen. Seal for high temperature water vapor environment. A rubber component in a braking system. A seal in a radiator (car water tank).

Nitrile butadiene rubber NBR

(Nitrile Rubber) is made of acrylonitrile and butadiene copolymerization, acrylonitrile content from 18% to 50%, the higher the content of acrylonitrile, the better the resistance to petrochemical oil hydrocarbon fuel oil, but the low temperature performance is poor, the general use temperature range of -25~100 ℃. Butane rubber is one of the most commonly used rubber for oil seals and O-rings at present. It has good oil resistance, water resistance, solvent resistance and high pressure oil resistance

Good compressibility, resistance to wear and elongation.

Disadvantages: Not suitable for use in polar solvents such as ketones, ozone, nitrohydrocarbons,MEK and chloroform. Used for making fuel tank, lubricating oil tank and rubber parts used in petroleum hydraulic oil, gasoline, water, silicone oil, diester lubricating oil and other fluid media, especially sealing parts. Can be said to be the most widely used, the lowest cost of rubber seals

Neoprene CR

(Neoprene, Polychloroprene) from the polymerization of chloroprene monomer. Vulcanized rubber has good elasticity and wear resistance, is not afraid of direct sunlight, has particularly good weather resistance, is not afraid of fierce distortion, is not afraid of refrigerant, is resistant to dilute acid, silicone ester lubricating oil, but is not resistant to phosphate ester hydraulic oil. It is easy to crystallize and harden at low temperature, with poor storage stability and large expansion in mineral oil with low aniline point. The general operating temperature range is -50~150 ℃. Advantages: good elasticity and good compression deformation, the formula does not contain sulfur, so it is very easy to make. It is resistant to animal and vegetable oils, and will not be affected by neutral chemicals, fats, oils, various oils and solvents

Disadvantages: It is not recommended to use R12 refrigerant seals among strong acids, nitrohydrocarbons, esters, chloroforms and ketones, rubber parts or seals on household appliances. Suitable for making all kinds of direct contact with the atmosphere, sunlight, ozone parts. Applicable to all kinds of fire resistant, chemical corrosion resistant rubber products.

Development of rubber products industry

Rubber industry is one of the important basic industries of national economy. It not only provides people with indispensable daily life, medical and other light industrial rubber products, but also to mining, transportation, construction, machinery, electronics and other heavy industries and emerging industries to provide a variety of rubber production equipment or rubber parts. It can be seen that the rubber industry has a wide range of products, and the backward industry is very broad.

In recent years, the rubber industry has been a lot of development, the segmentation industry has been growing steadily, the new rubber segmentation industry is developing rapidly, but at the same time, the rubber industry also exists environment, resources, disasters, innovation and other problems.

In 2004, the total planting area of natural rubber was 696,200 hectares, the cutting area was 451,900 hectares, and the production of dry rubber was 573,300 tons. Among them, the rubber planting area of agricultural reclamation is 411,000 hectares and that of private enterprises is 285,200 hectares, accounting for 59.03% and 40.97% of the total rubber area of China, respectively.

In 2005, hainan was hit by the rare drought in 50 years and the worst typhoon in 100 years, which hit the natural rubber production heavily. In order to excavate the development potential of domestic natural rubber planting and processing and increase self-sufficiency, China's rubber industry has made unremitting efforts, earnestly implemented the national security, energy saving, environmental protection and clean production guidelines, and made great achievements. In particular, the rubber additives industry actively adjusted the product structure, the green environmental protection additives increased substantially, the yield proportion of excellent varieties of anti-aging agent has reached 80%, promoters up to 50%, toxic, harmful, high carcinogenic NOBS production has been effectively controlled; The comprehensive utilization rate of waste rubber is above 65%, and the field of processing and utilization of recycled rubber and rubber powder is expanded.

In 2006, the third council of the sixth session of China Rubber Industry Association discussed and approved and issued the Opinions on scientific Development Plan of China rubber Industry in the 11th Five-Year Plan period and the opinions on implementing strategic planning of famous brand in the 11th Five-Year Plan period of China rubber Industry. This is the first industry plan organized by an association. The plan indicates that the rubber industry should take the road of independent innovation during the eleventh Five-Year Plan period, and the whole industry should effectively turn into the track of scientific development, so that China will become a powerful country in the world rubber industry.

The development prospect of China's rubber industry is broad. By 2010, China