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Application of EVA hot melt adhesive

2024-11-25

Hot melt adhesive is solvent-free, almost odorless, pollution-free, and easy to apply, so it is widely used in many fields. Hot melt adhesive with ethylene-vinyl acetate random copolymer (EVA) as the base resin is one of the most important varieties of hot melt adhesive, which can be used in packaging materials, book binding, wood processing and other industries.

 

The development of EVA hot melt adhesive in my country began in the early 1970s. In the 1980s, due to the rapid development of related industries and industries such as printing, food and beverage, wood processing, and electronics, various production lines were introduced to stimulate the rapid growth of new product development and production capacity of EVA hot melt adhesive. EVA hot melt adhesive is mainly used in the following fields in my country.

 

1 Book binding

EVA hot melt adhesive is used for wireless binding, which changes the cumbersome processes of threading round backs, gluing, and covering the cover used in the past for binding books with latex, greatly shortening the book publishing cycle and improving work efficiency and book binding quality.

2 Wood processing

In wood processing, EVA hot melt adhesive is mainly used in combination with panel furniture edge banding machines for furniture edge banding, which has changed the backward appearance of manual operation in the past, and is easy to fold and assemble, which improves labor efficiency.

3. Clothing lining

EVA and EVAL powders are inexpensive and have good adhesion. They are suitable for various coating processes such as powder coating, powder dot coating, and slurry coating. The hot melt lining made of EVA hot melt adhesive can make the clothing beautiful, crisp, non-deformed, and low-cost.

4 Packaging

The bonding ability of EVA hot melt adhesive is relatively stable, not affected by changes in temperature and humidity in the working environment, and eliminates the inherent gluing and peeling problems of packaging machinery. Therefore, EVA hot melt adhesive can be used in the packaging industry in the fields of cardboard and cardboard boxes, cement bags, labeling, food packaging, protective packaging, and packaging container sealing.

 

EVA hot melt adhesive is also used in the manufacture of electrical appliances such as televisions, air conditioners, refrigerators, as well as the shoemaking industry, PET blow molding bottles, cigarette filter winding, outer packaging tear strips, cable joint sealing, oil pipeline anti-corrosion and other fields.

 

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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.

Application of thermal conductive PVA film

2024-11-25

With the rapid development of modern electronic technology, thermal conductive materials are increasingly used in electronic devices. As a new type of thermal conductive material, thermally conductive PVA (polyvinyl alcohol) film has received widespread attention due to its excellent thermal conductivity, good mechanical strength and processing performance. Thermally conductive PVA film has a wide range of application prospects in the field of electronic equipment due to its excellent performance.

 

1. LED lighting: LED lamps generate a lot of heat during operation, and thermally conductive materials are required for effective heat dissipation. Thermally conductive PVA film can be used as a heat dissipation substrate or insulating gasket for LED lamps to improve heat dissipation efficiency and service life.

 

2. Electronic components: Electronic components will generate heat accumulation when working, affecting performance and life. Using thermal conductive PVA film as an isolation material or heat dissipation pad between components can effectively reduce the operating temperature and improve reliability.

 

3. New energy vehicles: The battery packs in new energy vehicles will generate a lot of heat when working and need to be dissipated in time to ensure safe and stable operation. Adding thermal conductive PVA film between battery packs can achieve effective heat dissipation and extend battery life.

 

4. Communication equipment: The power amplifiers, filters and other components in communication equipment will generate a lot of heat when working and need to be dissipated to avoid equipment damage or performance degradation. Using thermal conductive PVA film to wrap or fill around these components can achieve good heat dissipation and ensure normal and stable operation of the equipment.

 

 

Applications of PVA optical films

2024-11-25

PVA optical films have a wide range of applications, including optical lenses, display devices, filters and optical sensors. By using PVA optical film, the performance of optical devices can be improved and better optical effects can be achieved.

 

PVA optical film has high transparency and excellent optical properties. It can be used as a coating on the surface of optical lenses to improve the optical properties of the lenses. At the same time, PVA optical film also has the characteristics of wear resistance and anti-pollution, which can protect the lens surface and reduce damage.

 

With the development of electronic products, the demand for display devices is also getting higher and higher. PVA optical film has excellent polarizing effect and high contrast, which is especially suitable for polarizers of LCD displays. It can also be used as anti-reflective coating for touch screens, effectively reducing reflected light and improving the viewing experience.

 

PVA optical film has good tunability and can be used to make various optical filters. An optical filter is an optical component that selectively transmits or reflects light of specific wavelengths. Such as infrared filters, UV filters, etc. These filters have a wide range of applications in optical imaging, spectral analysis and other fields.

 

PVA optical films have excellent optical properties and stability and can be used to make high-sensitivity, high-resolution optical sensors. An optical sensor is a device that can convert optical signals into electrical signals and is widely used in optical measurement, optical communications and other fields.

 

With the continuous development of science and technology, the application prospects of PVA optical films in the optical field will be broader.

 

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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.

EVA resin properties and applications

2024-11-25

EVA resin is short for ethylene acetate-ethylene resin, which is a polymer made of ethylene acetate and ethylene monomer. According to the different contents of ethylene acetate, the copolymers of ethylene and ethylene acetate were divided into EVA resin, EVA rubber and VAE emulsion. .Products containing less than 40% vinyl acetate are EVA resins. 

 

EVA resin has good softness and shock-absorbing properties. It is one of the materials widely used in the footwear manufacturing industry and can be used to make soles, insoles, uppers and other components. It is also often used as a cushioning material, such as knee pads, wrist pads, and ankle pads in sporting goods, as well as car seat pads, motorcycle seat pads, etc.

 

EVA resin can be molded through various processing methods, such as extrusion, injection, calendering, etc., and it also has shock-absorbing properties. It is an excellent packaging material such as protective film, liner, protective cover, etc. to protect items during transportation and storage. No damage is caused during the process.

 

The chemical resistance of EVA resin can resist the erosion of many chemical substances. In medicine, EVA resin is often used to make medical instruments and equipment, such as surgical instruments, medical tapes, gloves, etc. It has good chemical resistance and transparency, and meets hygiene and health requirements. It is also an insulating material for electronic products, such as cable insulation tubes, insulating gaskets, etc. It can also be used as a protective material for batteries, with excellent chemical resistance and heat insulation properties.

 

In terms of building materials, EVA resin can be used as building materials, such as sound insulation panels, heat insulation panels, etc. It has good sound absorption, heat insulation and weather resistance properties, and can improve the comfort of buildings.

 

Agricultural use EVA resin can be used as agricultural covering film. It has good weather resistance and light transmittance, and can protect crops from bad weather.

 

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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.

Introduction to EVA hot melt adhesive

2024-11-25

EVA hot melt adhesive is a solvent-free, water-free, 100% solid fusible polymer. It is solid at room temperature and becomes a liquid adhesive that can flow and has a certain viscosity when heated and melted to a certain degree. It is light brown translucent or white after melting.

 

EVA hot melt adhesive is mainly made of the following four components: base resin, namely EVA resin, tackifying resin, wax, antioxidant, and a small amount of filler can be added in some occasions to increase the gap filling and reduce costs.

 

EVA hot melt adhesive has the following characteristics:

(1). It has fast curing, low pollution, strong adhesion, and the adhesive layer has certain flexibility, hardness, and toughness;

(2). After the adhesive liquid is applied to the adherend and cooled and solidified, the adhesive layer can be heated and melted again to become an adhesive body and then bonded to the adherend, with a certain degree of re-adhesion;

(3). When using, just heat and melt the hot melt adhesive into the required liquid state and apply it to the adherend. After pressing, the bonding and curing can be completed within a few seconds, and the hardening, cooling and drying can be achieved within a few minutes.

 

The type of EVA determines the cohesive strength, flexibility, adhesion to the substrate and processability of the hot melt adhesive. For hot melt adhesive, the following properties of EVA should be paid attention to: molecular weight and its distribution, vinyl acetate (VA) content, crystallinity, softening point, melting point, melt index (MI) and melt viscosity, etc., because these properties directly affect the various properties of hot melt adhesive.

 

As the melt index of EVA increases, its strength, hardness, softening point and viscosity all decrease regularly; and the more VA content in EVA, the greater the elongation at break and the lower the hardness. In addition, when the VA content exceeds 30%, although the adhesion to polar and various non-porous non-polar substrates is improved, this EVA polymer is incompatible with wax, which is a point to be noted when designing hot melt adhesive formulas. In a formula, it is often necessary to use EVA with different MI or EVA with different VA content to obtain satisfactory comprehensive performance.

 

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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.

Introduction to polyvinyl acetate

2024-11-25

Polyvinyl acetate (PVAC), also known as polyvinyl acetate. It is a polymer of vinyl acetate (vinyl acetate) with the chemical formula (C4H6O2)n. It is a colorless viscous liquid or light yellow transparent glassy particles, soluble in solvents such as benzene, acetone and chloroform. Vinyl acetate, the raw material used in PVAc emulsion, is one of the fifty most produced chemical raw materials in the world and is also the cheapest polymer monomer.

 

China's vinyl acetate output ranks among the top in the world. At present, more than 80% of the domestic vinyl acetate is used in the production of vinylon and polyvinyl alcohol. At the same time, downstream products such as PVAc emulsion, polyvinyl acetal and other copolymers are derived. At present, the domestic production of PVAc emulsion is more than 1 million tons.

 

The application fields of PVAc emulsion are very wide:

1. Construction industry, can be used for interior wall decorative coatings, colorful coatings, etc. It is also used for cement modification to improve the tensile strength, adhesion and chemical stability of cement mortar or concrete, and to prevent cracking, etc.

2. In the building materials industry, adhesive glue can be produced, such as woodworking glue, white latex, furniture glue, super glue, etc.

3. Paper industry, can be used as adhesive, impregnating agent, rewetting adhesive,

4. Packaging printing, can be used for plastic-plastic bonding, aluminum-plastic bonding, and post-processing of printed paper products

In addition, it has certain applications in textile printing and dyeing, fiberglass processing, and biomedicine.

 

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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.

Introduction to Polyvinyl Butyral resin

2024-11-25

PVB (Polyvinyl Butyral) is a synthetic resin, which is the product of the acid-catalyzed condensation of polyvinyl alcohol and butyraldehyde. It has many features and a wide range of applications. PVB molecules contain long branch chains, have good flexibility, low glass transition temperature, and high tensile strength and impact strength. PVB resin has good thermal bonding properties and can be connected to other materials through hot pressing or hot melting methods. It has excellent transparency, good solubility, good light resistance, water resistance, heat resistance, cold resistance and film-forming properties.

 

PVB resin has good weather resistance against ultraviolet radiation and atmospheric oxidation, and can provide long-term protection. Bonds well to glass and other materials. This makes PVB film an important material for manufacturing laminated glass, which can enhance the impact resistance and safety of the glass. This safety glass has good transparency and high impact strength, and is widely used in the aviation and automotive fields.

 

Because PVB resin has good transparency and optical properties, it is a transparent material with a high refractive index and low hygroscopicity. It is widely used in fields such as optical coatings, optical films and optical glasses.

 

PVB can also be used for flexo printing, gravure printing, embossing printing, screen printing, and thermal transfer printing in the printing industry. Because it is soluble in alcohol and non-toxic, the printed parts do not retain odor, and can be used in packaging that is sensitive to odor in the food industry. Such as teahttps://www.elephchem.comcigarettes, etc. Because the resin is cationic, it has adhesion to glass surfaces with strong anions, and is especially suitable for glass plate decorative silk screen printing.

 

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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.

Introduction to the production process of vinyl acetate

2024-11-25

Vinyl acetate is a colorless flammable liquid with a strong odor. Its vapor is irritating to the eyes. It is insoluble in water but soluble in most organic solvents. Vinyl acetate monomer is flammable and reacts rapidly with chlorine, bromine, and ozone. There are two production process routes for vinyl acetate monomer: the ethylene method and the acetylene method. The acetylene method can be divided into a liquid phase method and a gas phase method, and the ethylene method can also be divided into a liquid phase method and a gas phase method.

 

Acetylene gas phase method: desulfurized and dephosphinated calcium carbide acetylene and acetic acid are used as raw materials, the catalyst is zinc acetate-activated carbon (15:100), and a promoter is added. The reaction temperature is 170~200℃, the pressure is atmospheric pressure, and the space velocity is 200~400https://www.elephchem.comh. Reaction results: acetic acid single-pass conversion rate is 25~40%, acetylene single-pass conversion rate is 12~16%. The selectivity of VAM is 92~96% for acetylene and 95~98% for acetic acid. The total yield of VAM is 97~98% for acetic acid and 92~96% for acetylene.

 

The catalysts for the ethylene gas phase process are mainly Pd-Au, Pd-Pt and Pd-Cd supported catalysts, and the carriers are mainly silica gel and alumina. The two main factors affecting the catalyst are the coordination ability of Pd and the ability of acetic acid or acetate to oxidize Pd(0) to Pd(II). The single-pass conversion rate of ethylene in this process is 8~10%, the single-pass conversion rate of acetic acid is 8~20%, and the VAM selectivity based on ethylene is 90~94%.

 

In the past few years, the acetylene process has been gradually replaced by the ethylene process due to the high cost of raw materials. However, with the continuous rise in oil prices, the acetylene process has regained economic vitality, especially the acetylene process using natural gas as raw material. At present, the acetylene process still occupies an important position in China. The ethylene gas phase process occupies a dominant position in the market due to its good processability and economic performance. At present, the ethylene production technology in China accounts for more than 55% of the total national production capacity.

 

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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.

Medical applications of polyvinyl alcohol microspheres

2024-11-25

Polyvinyl alcohol (PVA) is a water-soluble polymer material widely used in the preparation of hemostatic fibers, artificial skin, plasma substitutes, etc. It can also be used as a drug sustained-release carrier material to prepare targeted microspheres. Animal experiments have shown that it is completely harmless and has good biocompatibility. It can be slowly degraded in the body, so it is widely used as a drug carrier. Polyvinyl alcohol microspheres with a particle size of less than 10 microns release drugs into the human body to achieve the purpose of treatment and immunity. For example, PVA microspheres made of erythropoietin, interferon, and cholera toxin B subunit can be absorbed orally. Through dispersion polymerization, polyvinyl alcohol microspheres with a size of 1-10μm can be prepared, and they can also be further chemically converted into various types of functionalized microspheres according to the different requirements of the application field.

 

Polyvinyl alcohol foam embolic microspheres are medical substances used for embolization of blood vessels. They are mainly composed of polyvinyl alcohol andhttps://www.elephchem.comor polyglycolide and are specially treated to enable them to swell and embolize blood vessels. Such microparticles are often used in intravascular surgery to prevent blood from flowing into and contaminating the surgical area. In addition, they can also be used to treat ischemic stroke and other vascular diseases.

 

Features of polyvinyl alcohol foam embolic microspheres include: it can swell upon contact with blood and quickly solidify, thereby effectively embolizing blood vessels. The microspheres are degradable and will be absorbed by the body after a period of time, which helps reduce the risk of complications. In addition, it can be combined with other substances (such as drugs) to achieve specific therapeutic purposes. When using polyvinyl alcohol foam embolic microspheres, strict guidelines and standard operating procedures need to be followed. These microspheres are usually inserted into blood vessels by medical professionals when using endovascular procedures.

 

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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.

Preparation of thermal conductive PVA films

2024-11-25

As a new type of thermal conductive material, thermal conductive PVA (polyvinyl alcohol) film has excellent thermal conductivity, good mechanical strength and processing performance. The preparation of thermal conductive PVA film mainly includes raw material selection, blending modification, film forming process and post-processing.

 

Raw material selection: The main raw material of thermal conductive PVA film is polyvinyl alcohol resin, and a certain amount of thermal conductive filler, such as oxygen, needs to be added Aluminum, boron nitride, etc. The addition of these fillers can effectively improve the thermal conductivity of PVA films.

 

Blending modification: the polyvinyl alcohol resin is mixed with the thermal conductive filler in a certain proportion, and the blending modification is carried out by high-speed stirring, ball milling and other methods. During the blending process, the filler particles are uniformly dispersed in the resin matrix to form a thermal conductivity network, thereby improving the thermal conductivity of the material.

 

Film forming process: the blended modified slurry is made into a film by casting, calendering or extrusion processes. In the film forming process, parameters such as temperature, pressure and speed need to be controlled to ensure the thickness, uniformity and surface quality of the film.

 

Post-treatment: Post-treatment processes such as drying and heat setting need to be carried out after film formation to eliminate the internal stress inside the film and improve dimensional stability.

 

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