Safety technology of the hottest coating and coati

2022-07-29
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Safety technology for coating and coating operations in recent years, China's plastic machinery enterprises have increased their efforts to open up emerging markets for extruders. Most of the raw materials used in coating production and coating operations contain volatile organic solvents, resins, pigments, etc. that are easy to catch fire and harmful to human health. Therefore, there is always the possibility of fire and even explosion in coating production and coating operation

fire: 1. Gas fire; 2. Oil ignition; 3. Flammable fire; 4. Electrical fire; 5. Metal fire; 6. Excess oxygen fire

explosion: 1. Mixed gas explosion; 2. Explosion of gas decomposition; 3. Dust explosion; 4. Explosion caused by mixed dangerous substances; 5. Explosion of explosive compounds; 6. Vapor explosion

hazardous substances: 1. Combustible gas; 2. Flammable liquid; 3. Flammable substances; 4. Combustible dust; 5. Nature of explosives; 6. Pyrophoric substances; 7. Avoid water-based substances; 8. Mixing hazardous substances

ignition source: 1. Impact friction; 2. Open flame; 3. High temperature surface; 4. Optional heating; 5. Adiabatic compression; 6. Electrical sparks; 7. Electrostatic spark; 8. Light and ray

dangerous substances may cause fire or explosion when encountering fire source

for this reason, the use of solvents, pigments and resins in the world is more stringent every year. The United States has developed from "regulation 66" to "regulation 1113". The U. EPA pays great attention to some special industries. They are focusing on the composition of waste generated in the manufacturing process of some organic pigments, studying the toxicity of these chemicals, and listing some pigment intermediates in the list of 2800 harmful chemicals with swing restriction function. The Chinese government has also issued a series of regulations on the safety of coatings and coatings

therefore, it is a very significant event to study and understand the safety technology in the process of coating production and coating construction, and do a good job in safety production, which should be highly valued by all parties

2 main film-forming substances of coatings

composition of general coatings are as follows:

composition of general coatings: (1) main film-forming substances a, natural resin; B. Synthetic resin; C. Vegetable oil; D. Others

(2) secondary film-forming substances a and pigments; B. Physical pigments

(3) additive A, solvent, cosolvent and diluent forming the film; B. Additives (toughening agent, drying agent, solid agent, leveling agent, etc.)

generally speaking, the resin and vegetable oil in the main film-forming substances are harmless or do little harm, but some free monomers are toxic, and the more serious ones are isocyanates. These compounds mainly exist in polyurethane coatings, which have irritating effects on human mucosa and upper respiratory tract

there are many toxic and harmful substances in the raw materials of synthetic resins. For example, phenolic resin is formed by heating and condensation of phenol, cresol, xylenol, etc. with formaldehyde. Phenols can be used as disinfectants, but phenol vapor inhaled from the respiratory tract will cause poisoning. High concentration phenols can cause acute poisoning, even coma and death. When the concentration of phenol in the water is high, it will cause the death of fish. When the concentration of phenol containing wastewater is greater than 100mg/l, it will cause the withering of crops or reduction of production. Formaldehyde has the function of destroying protein and sterilization, which can cause inflammation of respiratory tract, contact dermatitis and damage to eyes and cornea. Its pungent smell will also cause people's disgust. In recent years, the restrictions on formaldehyde in indoor decoration have been gradually tightened. Secondly, materials with high hardness of amino resin (formaldehyde should also be used) are very brittle. 1 pull off alkyd resin and polyester resin (phthalic anhydride should be used, which will cause bronchitis, ophthalmia, emphysema and other symptoms, and also stimulate the skin). Epoxy resin should use phenols and epichlorohydrin, and aliphatic amine should be used when curing. Polyurethane, vinyl chloride resin, acrylic resin, etc. will bring harm to human body. In particular, when the application of coatings in construction and industry is greatly increased, people's living standards are improved, the family decoration heat is heating up again and again, and the adverse factors to human body caused by decoration are increasing, people also put forward stricter requirements for the toxicity and application of coatings. In many foreign countries, the requirements for coatings have also changed from general technical standards to technical standards + biological toxicity, that is, to people's friendly and healthy standards. This standard greatly limits the application of many toxic compounds. China has issued a series of mandatory standards to strictly limit the exhaust gas from indoor decoration

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