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The global consumption structure of polyvinyl alcohol (PVA) is: polymerization assistants account for about 24%, polyvinyl butyral (PVB) accounts for about 15%, adhesives account for about 14%, textile pulp accounts for about 14%, and paper pulp Materials and coatings account for about 10%, and others 23%.   The consumption structure of polyvinyl alcohol (PVA) in China is: polymerization assistants account for about 38%, fabric slurries account for about 20%, adhesives account for about 12%, vinylon fibers account for about 11%, papermaking slurries and coatings account for about 8% %, architectural coatings account for about 5%, and others 6%. Polymerization aids, fabric sizing and adhesives are the main downstream consumer markets for polyvinyl alcohol.   In the first half of 2023, the supply and demand of China PVA products were in a weak balance, and prices were running at low levels. The advantages of China PVA variety in supporting a stable market share. With the introduction of new technologies, new processes, and new products, the continuous expansion of new application fields, and the gradual replacement of imported products, new development opportunities have been brought to the domestic polyvinyl alcohol and vinylon industry. However, as various companies increase their export efforts and adopt fierce competition at the low end, and with the adjustment of China's industrial structure, rising wages and other costs, and high environmental protection requirements, some downstream industries, such as the labor-intensive textile industry, have relocated to Southeast Asia, making domestic Demand growth momentum has slowed, foreign consumption has increased, and exports have increased. After more than ten years of competitive integration and optimization, the industry is showing a new pattern of optimized production capacity, increased concentration, stable market varieties, slow growth in market demand, high technical barriers, moderate competition, and innovation-driven development, reaching a new balance between supply and demand. Develop into a benign new business format.   With the rapid development of PVA downstream industries such as PVA optical film, PVB film, polymerization additives, soil improvement, paper adhesives, ceramic adhesives, environmental protection, medicine and cosmetics, the demand for special PVA products is very strong, and Anhui The special PVA products of leading enterprises in the industry represented by ElephChem have developed rapidly, and they have increased their research and development efforts on PVA fiber, PVB resin, PVB film, PVA optical film, redispersible rubber powder and other products. Special varieties of PVA and The production technology of downstream new material products is becoming increasingly mature, filling many gaps in the country. New PVA products are gradually being put on the market, and their market share is also constantly increasing. Common varieties have basically achieved import substitution, and the downstream consumption structure of the domestic PVA industry has been further expanded.

China is one of the world's largest PVA production countries, since 1965 Beijing Oriental Petrochemical Co., LTD. (the former Beijing Organic Chemical plant) from Japan to introduce technology to build China's first set of calcium carbide acetylene method (from calcium carbide acetylene method to petroleum ethylene method in 1995) PVA production plant, China's PVA production has developed steadily.   According to statistics, in 2015, China's polyvinyl alcohol (PVA) production was about 700,000 tons, increasing to 802,000 tons in 2022, with a compound annual growth rate of 1.96% during the period. In terms of demand, the apparent consumption of PVA in China in 2022 was 639,600 tons, an increase of 2.16%. Common types such as PVA 2488, PVA 2088 and PVA 0588 are in great demand in various fields.   Output and consumption

Vinylon is the trade name of polyvinyl acetal fiber, also known as Vinylon. Its performance is close to cotton, known as 'synthetic cotton', is the largest variety of existing synthetic fibers in hygroscopicity. It is not easy to ignite, near the flame melting contraction, there is a little flame at the top of the burning, when the fiber is melted into a gel, the flame becomes larger, there is thick black smoke, emitting bitter aroma, and the black small beaded particles are left after burning, which can be crushed by fingers.   Vinylon is the most hygroscopic variety in synthetic fibers, with a hygroscopic rate of 4.5% to 5%, close to cotton (8%). Vinylon is soft and warm, and its relative density is smaller than cotton, so the same weight of Vinylon with cotton can weave more clothing. Its thermal conductivity is low, so the warmth is good. The wear resistance and strength of Vinylon are also better than cotton, so Vinylon can be blended with cotton in many ways to save cotton. Vinylon is mainly used in the production of garments, cotton sweaters, pants, sweatshirts and other knitted fabrics, can also be used in canvas, fishing nets, surgical stitches, bicycle tire cord, filter materials. More and cotton blend: muslin, poplin, corduroy, underwear, canvas, tarps, packaging materials, work clothes, etc.   The main component of Vinylon is polyvinyl alcohol(PVA), but vinyl alcohol is unstable, generally with stable performance of vinyl alcohol acetate (that is, vinyl acetate) as a monomer polymerization, and then the generated polyvinyl acetate alcohol hydrolysis to polyvinyl alcohol, spinning and then treated with formaldehyde, in the polymer chain to introduce a six-membered ring structure to generate polyvinyl formaldehyde, enhance its strength. To get water resistant Vinylon.   The manufacture of industrial vinylon fiber is to dissolve polyvinyl alcohol in water to produce about 15% aqueous solution, through the spinneret with a diameter of about 0.07 mm, in the saturated sodium sulfate aqueous solution solidification bath to produce fiber, and then stretching and heat treatment to improve strength and heat resistance; Then in the presence of catalyst sulfuric acid, acetal reaction with formaldehyde, the temperature is about 70℃, the time is 20 to 30 minutes, after washing, oil to obtain Vinylon fiber. Vinylon fiber has short fiber, tow and filament and other varieties, of which cotton type short fiber and tow are the most common.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.

The different mesh numbers of PVA should be selected according to the specific application needs, to ensure the best effect. The mesh number of PVA indicates its particle size, the larger the mesh number, the smaller the particle diameter. For example, ‌120 purpose polyvinyl alcohol particle size is smaller, ‌under the action of surfactants, can be better adsorbed and coated by liquid, the lubricity, and other properties are better than 80 purpose polyvinyl alcohol. ‌, therefore, ‌ when it is necessary to use polyvinyl alcohol, ‌ should be selected according to the specific application needs of different mesh of polyvinyl alcohol. In addition, the common mesh of ‌ polyvinyl alcohol includes 12 mesh, 20 mesh, 25 mesh, ‌80 mesh and 120 mesh, ‌ grinding into powder can improve the dissolution rate of polyvinyl alcohol, ‌ but not the finer the better, the powder will lump as long as it is soaked with water, especially when the dosage is large. On the contrary, it is not conducive to the dissolution of PVA.    When dissolving more than 80 mesh PVA powder, pay attention to the way of adding, need to stir quickly, add slowly, to prevent more powder together when encountering water. Dissolved larger particles of powder below 80 mesh PVA basically will not lump, but at room temperature dissolution is slower, you can stir or increase the dissolution temperature, thereby accelerating the dissolution of PVA.   Therefore, the appropriate mesh number should be selected according to the different requirements of the product and the situation of the reactor of the existing equipment.   ElephChem can provide a variety of PVA powder with different mesh sizes, welcome to consult: Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.

Using the existing coating machine, dry composite machine and other equipment of domestic flexible packaging enterprises, after coating PVA coating solution of only 0.5g/m2 ~ 0.8g/m2 (dry base) on the film with qualified surface tension (such as PET, BOPP, CPP, PE and other films), The oxygen permeability of the film is less than 2cm3/ (m2·24h·0.1MPa), or even less than 0.5cm3/ (m2·24h·0.1MPa). Obviously, the oxygen resistance of the product has been significantly better than the five-layer co-extruded film with EVOH as a barrier layer and PVDC high barrier coating film, which is close to the oxygen resistance of aluminum foil. Advantages1, high cost performanceThe production cost of modified PVA coated high barrier film is much lower than the production cost of paper aluminum-plastic composite and aluminum-plastic composite structure packaging materials, and also lower than the cost of PVDC coated composite film. 2, excellent oxygen resistanceThe modified polyvinyl alcohol (PVOH) composite film has good barrier property to oxygen, nitrogen, hydrogen and carbon dioxide, and its oxygen inhibition property is much better than PVDC composite film. 3, excellent perfuming performanceIt can maintain the original flavor of the food in the bag for a long time, and at the same time, it can effectively prevent the odor outside the packaging material from entering the bag. 4, excellent environmental protection materialsPVA coating liquid is composed of carbon, oxygen, hydrogen and silicon, which can be degraded, recycled and reused, and does not produce toxic gases after combustion. It is an ideal packaging material.   ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.

Polyvinyl alcohol defoamer is a kind of surfactants commonly used in the chemical field, and it is widely used in the chemical industry. Its main role is in the production process, can effectively reduce the foaming phenomenon, also known as foaming agent or foam inhibitor.   Properties of polyvinyl alcohol defoamer 1. With low surface tension, it can effectively destroy the tension on the surface of the liquid, so that the liquid molecules repel each other, and the molecular combination will no longer occur to produce foam.2.Polyvinyl alcohol defoamer has good dispersion performance, which can re-disperse dispersed bubbles in the liquid, thereby avoiding foam deposition and reducing energy waste.3. PVA defoamer can form a relatively stable dispersed liquid system, making its distribution in the liquid more uniform, thereby reducing the generation of foam.4. Its role is to change the interaction force between molecules, and the physical and chemical properties of the solution have no obvious relationship, will not affect the composition of the solution and chemical reaction.   The role of PVA defoamer in production 1. Reduce energy consumptionThe application of PVA defoamer can effectively reduce the resistance of air and bubbles to liquid, reduce the consumption of pumping energy and stirring energy, and thus save energy.2. Improve production efficiencyIn some special occasions, the generation of foam will have a negative impact on production efficiency, the use of PVA defoamer can effectively reduce the generation of foam and improve production efficiency.3. Improve product qualityThe use of polyvinyl alcohol defoamer can effectively control the foam generation, reduce the tension of the liquid surface, make the product surface more flat and smooth, so as to improve the product quality. To sum up, PVA defoamer is one of the excellent surfactants, which is widely used in various industrial fields. In practical application, we should choose the corresponding defoamer according to the specific production needs to achieve the best effect.   ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.

Polyvinyl alcohol 2688 is a polymer compound with the formula (C2H40)n, where the value of n is greater than or equal to 1000. It is a polymer in chemical structure, its molecular weight is very high, and it has very special physical and chemical properties. The most important thing about the properties of PVA 2688 is its viscosity. Viscosity is a basic property of liquid fluidity and describes the degree of viscosity of a liquid. The viscosity of PVA 2688 is often used to describe its viscosity in aqueous solutions, and its value is generally measured at 20 ° C.    PVA 2688 has a viscosity of up to 50(mPa.s), which makes it a very viscous polymer compound. Due to its high molecular weight, the interaction between molecular chains is very strong, so the molecular chain of PVA 2688 is difficult to flow, and its viscosity is high. At the same time, because the polyvinyl alcohol 2688 molecule contains a large number of hydroxyl (-OH) groups, these groups can form hydrogen bonds with water molecules, so that it has good solubility in water.   The viscosity of PVA 2688 directly affects its performance in practical applications, so it is usually necessary to select an appropriate viscosity range. According to the actual process and needs, different viscosities of polyvinyl alcohol 2688 can be selected for application. The high viscosity of PVA 2688 makes it widely used in industrial and agricultural fields. For example, it is used in the manufacture of textiles, paper, paint adhesives and other products. In addition, it can also be used for the preparation of certain pharmaceuticals, daily chemical supplies and so on. Due to its good solubility in water, it is also used as a precipitator, dispersant, lubricant, etc., and PVA 2688 has a wide range of application prospects.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com   ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.

Polyvinyl alcohol 1788 is a colorless, transparent, viscous polymer compound consisting of alternating arrangements of vinyl and hydroxyl units. It is often used in the preparation of glue, coatings, textiles, medicine and other fields.   Polyvinyl alcohol 1788 has good solubility, can be dissolved in water, can also be dissolved in alcohols, esters and other organic solvents. Its solubility decreases with the increase of molecular weight. In dry air, PVA 1788 is relatively stable, but it breaks down in sunlight.   Polyvinyl alcohol 1788 is an important polymer material, which is widely used in various fields. The main uses of PVA 1788 are as follows: 1. Glue preparationPVA 1788 can be used to prepare various glues, such as woodworking glue, paper glue and so on. Dissolve PVA 1788 in water, then add crosslinking agent and auxiliary agent, after stirring, filtration, defoaming and other process steps, you can get glue. 2. Coating preparationPVA 1788 can be used to prepare various coatings, such as wall coatings, wood coatings and so on. The polyvinyl alcohol 1788 is dissolved in water, and then added pigments, fillers, auxiliaries, etc., after mixing, grinding, filtration and other process steps, the paint can be obtained. 3. Textile processingPVA 1788 can be used in textile processing, such as the processing and printing of cellulose fibers. Dissolve PVA 1788 in water, then add dyes, additives, etc., after soaking, drying and other process steps, dyed cellulose fiber can be obtained. 4. The field of medicinePVA 1788 can be used to prepare medicine, such as oral medicine, injections, eye drops and so on. Dissolve PVA 1788 in water, then add drugs, auxiliaries, etc., after mixing, filtration, sterilization and other process steps, you can get the drug.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com   ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.

Dispersion polymerization is another kind of heterogeneous free radical polymerization of alene monomers except suspension polymerization and emulsion polymerization. Dispersion polymerization can be regarded as a polymerization between suspension polymerization and emulsion polymerization, and its characteristics are as follows: 1) Water or non-water solvent can be used as the medium. When water is used as a medium, the monomer must be insoluble in water or substantially insoluble in water.2) The dispersion of monomers in water is achieved by intense agitation, and the protective colloid added to the system plays a role in preventing the agglomeration of dispersed phases.3) Water-soluble initiators are required for dispersion polymerization with water as the medium.   In form, dispersion polymerization has many similarities with emulsion polymerization. But there are clear differences. Dispersion polymerization, for example, does not use typical emulsifiers but uses protective colloid to stabilize the polymerization system; The particles obtained by polymerization are larger than those obtained by emulsion polymerization. Let's wait.The polymerization of vinyl acetate in water with polyvinyl alcohol as a protective colloid is a typical dispersion polymerization. Vinyl acetate is a water-soluble monomer with a solubility of about 2.5% in water at room temperature and is easily hydrolyzed. The hydrolysis product acetic acid can seriously interfere with the normal process of polymerization. Therefore, the dispersion polymerization of vinyl acetate has more complicated factors than the common emulsion polymerization. It is believed that the dispersion polymerization of vinyl acetate does not occur in micelles, but the monomer dissolved in water is first polymerized, and when the molecular weight reaches a certain level, the polymer precipitates from the water to form latex particles on the protective colloid. In order to improve the stability of the polymerization system and products, an appropriate amount of emulsifier is added in the dispersion polymerization of vinyl acetate, but the role of emulsifier in polymerization is auxiliary.   Attentions： PVA usually has two specifications of 1788 and 1799 (17 indicates a degree of polymerization of 1700, 88 and 99 indicate an alcoholysis degree of 88% and 99%, respectively). When used as a dispersion polymerization protective colloid, it is best to use 1788, and the resulting product has good stability.2. In the polymerization process, the monomer droplet acceleration should be slow and not fast. Generally, a slight reflux in the condenser is appropriate.3. The boiling point of vinyl acetate is between 70-75℃. After adding drops, the heating rate should be slow, too fast and easy to caking.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com   ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.

The production process of polyvinyl alcohol can be divided into ethylene method and acetylene method according to raw materials. Acetylene synthesis can be divided into calcium carbide acetylene synthesis and natural gas cracking acetylene synthesis according to the different sources of raw materials. Calcium carbide acetylene synthesis, the first to achieve industrial production. Due to the high energy consumption, low quality and high cost of the products of this process route, the impurities generated by the production process pollute the environment is also more serious, and the lack of market competitiveness is gradually eliminated. In areas rich in natural gas, coal and electric power, natural gas acetylene synthesis is still vital.The process of synthesis of polyvinyl alcohol by ethylene method includes five steps: obtaining ethylene and synthesis of vinyl acetate, rectification, polymerization, alcoholysis of polyvinyl acetate (PVAc), recovery of acetic acid and methanol.   Vinyl acetate polymerization:   After preheating, ethylene acetate was mixed with solvent methanol and initiator azodiisobutyronitrile and sent to two tandem polymerization reactors for polymerization at 66 ~ 68℃ and atmospheric pressure. After polymerization for 4 ~ 6H, about 2/3 of vinyl acetate was polymerized into polyvinyl acetate. The heat generated by the polymerization reaction can be carried away by the evaporation of methanol, and the methanol vapor is condensed and returned to the polymerization kettle. The polymerization liquid is sent to the monomer to blow out the tower, and the unpolymerized vinyl acetate is blown out with methanol vapor. The ethylene acetate and methanol blown by the monomer blowout tower are separated and distilled, recovered and recycled. The polymerization solution was sent to the alcoholysis section for alcoholysis with methanol adjusted to 33% polyvinyl acetate.   Polyvinyl acetate alcoholysis: Polyvinyl acetate and sodium hydroxide methanol solution were mixed into a high-speed mixer at the ratio of polyvinyl acetate: methanol: sodium hydroxide: water at 1∶2∶0.01∶0.002 at the same time, and then entered the belt alcoholysis machine for alcoholysis at 50℃. The belt was moved at a speed of 1.1 ~ 1.2m/min, and the alcoholysis was completed in about 4 minutes. To obtain cured polyvinyl alcohol. After the solvent was removed by grinding, pressing and drying, the finished polyvinyl alcohol was obtained.   Recovery of methyl acetate: The extruded liquid contains a lot of methyl acetate and methanol. First, the azeotrope of methyl acetate and methanol is steamed in the azeotrope distillation column, and the bottom of the column is methanol aqueous solution. Methyl acetate and methanol azeotrope into the water extraction separation column and mixed with water, the top of the column separated methyl acetate, the bottom of the column is methanol aqueous solution. Methyl acetate was catalyzed by ion exchange resin in a hydrolyzer to obtain a mixture of acetic acid and methanol. The mixture is sent to a hydrolysate distillation column, where methanol and unhydrolyzed methyl acetate are steamed out and fed into a water extraction separation column. The bottom of the hydrolysate distillation column is dilute acetic acid, which is obtained after being sent to the dilute acetic acid concentration column to remove the water. The methanol aqueous solution obtained from the bottom of the azeotropic distillation tower and the water extraction separation tower can be reused by steaming the methanol in the methanol distillation tower.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.  

When VAE is mixed with sand slurry, many properties are improved, but the properties of mortar are also different due to the amount of emulsion mixed in mortar. According to research, from the comprehensive point of view of performance and economy, it is considered that the P/C (polymer weight/cement weight) value is between 0.1 and 0.4.   Increase mortar strength: The fluidity (flow value) of the mortar increases with the increase of the amount of emulsion added, and can rely on mixing with the emulsion to reduce the amount of water, so as to obtain a dense hardened substance, and can increase the strength, so that the shrinkage rate and water absorption decline. Improve the brittleness of mortar: When VAE emulsions are mixed into it, vibration-absorbing polymer particles fill the cement Spaces, thus improving the impact resistance of the mortar. Improve chemical resistance: The mixed VAE emulsion can improve the acid resistance of the mortar and prevent the corrosion of salt water, machine oil, ammonia, methanol and other chemicals.   The use of synthetic resins can improve the strength and adhesion of concrete, mortar, etc: The synthetic resin solution is applied to the surface of the original concrete or mortar, and then the surface is covered with new concrete or mortar, which can eliminate the "rough work" process. At present, polyvinyl acetate emulsions and styrene-butadiene rubber latex are commonly used, and VAE emulsions have greater bond strength than these two emulsions. Pure mortar has no bonding strength for wood, metal, plastic, etc., and only when the polymer is mixed in, the mortar can bond with wood, etc. High strength can be obtained by curing in the air (it is not necessary to spray water onto the poured mortar). If the hydration reaction of cement products is not sufficient, then it cannot get the inherent strength, so if the mortar is cured in the air, then it is brittle and easy to crack. If VAE emulsions are mixed in, the strong hydration force of the emulsions prevents the mortar from losing water too quickly, thus providing the moisture needed for cement curing.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.  

VAE(ethylene-vinyl acetate copolymer) emulsions are widely used in civil engineering and building structures because of their excellent water resistance, acid and alkali resistance, aging stability and low price.   VAE emulsion is non-toxic, odorless, green and environmentally friendly, and has excellent bonding effect on many different surfaces. It is an excellent adhesive. In the field of construction, it can be used to prepare tile adhesive, concrete repair, building insulation wall construction, self-leveling mortar and other fields.   The waterproof coating with VAE emulsion as the base material has excellent weather resistance, acid and alkali resistance and UV resistance. It can be used for waterproofing treatment of special-shaped roofing, repair of old roofing and construction of colored roofing, and for waterproofing coating of sanitary ware.   The addition of VAE emulsion to cement can not only greatly improve the strength of cement, but also achieve excellent results in repairing concrete and anti-seepage treatment of reservoir.   VAE emulsion mixed in mortar can increase the strength, can improve the adhesion to various substrates, can increase the resistance and impact resistance, can improve the water absorption and water permeability, can improve the chemical resistance, this polymer mortar due to its excellent performance, is now widely used.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com   ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.