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It is a liquid that flows out when the rubber tree is tapped. It is milky white with a solid content of 30% to 40%. The average rubber particle size is 1.06 microns.


1 category

Latex can be divided into three categories: natural, synthetic and artificial.

① Natural latex

It is a liquid that flows out from a rubber tree with a certain age when it is tapped according to a prescribed incision at a prescribed time. It is milky white with a solid content of 30% to 40% and an average rubber particle size of 1.06 microns. Fresh natural latex contains 27% ~ 41.3% (mass) rubber content, 44% ~ 70% water, 0.2% ~ 4.5% protein, 2% ~ 5% natural resin, 0.36% ~ 4.2% sugar, and 0.4% ash. To prevent natural latex from solidifying due to the action of microorganisms and enzymes, ammonia and other stabilizers are often added. Natural latex is mainly used to make sponge products, extruded products and impregnated products.

② synthetic latex

Generally made by emulsion polymerization, such as polybutadiene latex, styrene-butadiene latex and the like. In order to achieve a solid content of 40% to 70%, the rubber particles are first agglomerated into larger particles, and then concentrated by a method similar to natural latex. Synthetic latex is mainly used in industrial sectors such as carpet, paper, textile, printing, coatings and adhesives.

③ artificial latex

It is a non-emulsion polymerized rubber latex. Water and a surfactant are added to the colloid formed by the solution polymerization to disperse the rubber particles in water, and then the solvent is distilled off. If the rubber cannot be sufficiently dissolved in the solvent, the raw rubber and the rubber compound can be continuously kneaded in the presence of an aqueous phase containing an emulsifier until a stable aqueous rubber dispersion is formed. The use of artificial latex and synthetic latex is basically the same.

2 functions

1.Anti-mite and anti-bacteria

According to medical reports, pillows, bedding, and mattresses are breeding grounds for bacteria and dust mites, and pillows contain 10% of mold, mite feces, and mite corpses throughout the three years of use. According to medical information, 12% to 16% of people have allergies, and 25% of these patients are allergies caused by dust in the home; in addition, up to 90% of patients with asthma are caused by dust in the home From this, we can know the degree of harm to people from dust.

The oak protein in latex can inhibit the germs and allergens from latent, meet the requirements of environmental protection, can inhibit the breeding of germs and mites, and is static-free. It has a natural milky fragrance, making it deeply troubled by asthma and allergic rhinitis and other respiratory diseases. People benefit.

2, breathable

Natural latex pillows have thousands of fine mesh structured vent holes. These holes can dissipate residual heat and moisture from the human body, promote natural ventilation, and provide a natural air conditioning system to keep the air inside the pillows fresh and healthy.

3 price status

Hujiao 1301 gapped and opened lower, intraday trading fluctuated upward, and finally closed at 24845, closing down 15 yuan. Funds have been shrinking to increase positions, and the top 20 members have been short to reduce their positions, and long positions have significantly increased their positions.

In the spot market, the spot price of all latex generally fell on Monday, and traders were not enthusiastic in quoting, and the trading was deadlocked. The price of private latex in Yunnan was 23,400, and the spot discount was 1,400 yuan. The ex-factory price of synthetic rubber is basically stable. The ex-factory price of Qilu Petrochemical's butadiene rubber model BR9000 is reduced by 50 yuan.

In terms of 彩乐乐网, the National Bureau of Statistics announced that China ’s tire output in September was 77.22 million, a year-on-year increase of 2.3%. The end of the U.S. tire special insurance case is good for the export of Chinese tires to the United States. Therefore, it is expected that China's tire output will continue to rebound in October.

Technically, Hujiao 1301 rose in late trading and closed above the 20-day moving average. If the futures price continues to stand firm at 24800 tomorrow, it will be backed by 24800 light warehouses, referring to the 20-day moving average stop loss.

4 natural latex

composition

Natural latex is a milky white liquid that looks like milk. Natural latex is a biosynthetic product. Due to differences in tree species, geology, climate, and other related conditions, there may often be huge differences in its composition and colloidal structure. In fresh latex without any added substances, rubber hydrocarbons only account for 20% -40% of the total, and the rest are a small amount of non-rubber components and water. Non-rubber components include proteins, lipids, sugars, and inorganic components. Some of them form a composite structure with rubber particles, and some of them are dissolved in whey or form non-rubber particles.

Physical properties

(A) concentration

The concentration of the latex is expressed by the total solids content and the dry rubber content. The dry rubber content refers to the content of dry rubber in the latex, and the total solid content refers to the content of all solid substances in the latex after removing water and volatile components, expressed as a percentage. There is generally a difference between the total solid content and the dry rubber content. This value is called the total dry difference, which is used to explain the content of nonvolatile non-rubber components in the latex. These indicators are of great significance for guiding production and product quality.

The concentration of fresh latex varies with tree age, season, and tapping system, and generally only has a total solid content of 20% -40%.

(2) Relative density

The relative density of fresh latex is about 0.96-0.98, which is determined by the relative density of whey (1.02) and the relative density of rubber hydrocarbons (0.9064). From the relative density, the content of rubber hydrocarbons in latex can be approximated. The higher the rubber hydrocarbon content, the lower the relative density of the latex, as shown in the table.

(Three) viscosity

Fresh latex with a total solid content of about 35% has a viscosity of about 12-15 mPa · s, which varies greatly with the collection period and other factors. Generally, the higher the total solids content is, the higher the viscosity is, but the latexes of the same total solids content will be relatively different in viscosity due to different storage methods, storage time, and particle size.

(Four) surface tension

The size of the surface tension indicates that the latex is evenly distributed on the surface of the solid-the so-called wetting performance. Rubber is insoluble in water, but latex contains a large amount of surface-active substances, such as proteins and fatty acids, which can reduce the surface tension of water. For example, the latex with a total solid content of 38% to 40% has a surface tension of about 38 to 40mN / m, which is much lower than that of water (72mN / m), so it has the ability to wet and penetrate hydrophilic surfaces such as cloth and leather. The energy often increases with the decrease of its surface tension. When the latex still cannot meet the process requirements in production, some surfactants need to be added to further improve the surface properties and increase wettability.

(E) PH value

The pH of the latex has a great influence on its stability. Fresh latex is neutral and slightly alkaline, with a pH of 7 ~ 7.2. After several hours to more than ten hours, due to the effects of bacteria and enzymes in the latex, the pH value will decrease and become acidic, causing coagulation. For this reason, ammonia or other bases are often added to increase the pH to 10 ~ 10.5 so that it can be stored for a longer period of time.

use

Mainly used in latex impregnated products: (meteorology, festivals, toys) balloons, (medical, household, industrial) gloves, pacifiers, condoms; sponge products: sponges (mattresses, pillows, shoe soles); injection molded products : Latex toys, gas masks, make-up appliances, footwear; Molded products: Latex and silk, medical supplies; Other applications: (wool, brown, animal and plant and artificial synthetic fibers, artificial leather) bonding, flocking, non-woven fabrics , Carpet, textile, paper, and adhesives, etc.

References

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