The main source of air pollution in steel structure factory is the surface painting process. The traditional coating is used in the surface coating of steel structure factory now, which leads to pungent odor, excessive pollution and failure of environmental assessment. The environmental protection bureau often inspects it, which seriously affects the production and development of enterprises.
1、 Main reasons for failure of EIA of steel structure plant
Steel structure factory products must be surface coated before leaving the factory, mainly antirust and anti-corrosion. The coatings used are mainly chlorosulfonated polyethylene anticorrosive coating, iron red phenolic resin antirust coating and a small amount of alkyd blending coating. These coatings produce a lot of organic waste gas in the process of spraying and curing, which not only has a pungent taste, but also causes serious environmental pollution.
2、 Harm of spraying high concentration VOCs coating in steel structure factory
1. Serious air pollution
Coatings are widely used in steel structure plants. A large amount of organic volatiles are discharged into the atmosphere during the use process, which makes the atmospheric environment a victim of enterprise development.
Experts analyze that traditional coatings contain a large number of VOCs, which will volatilize a large number of toxic chemical substances in the process of use. Among them, benzene, formaldehyde and xylene are toxic and harmful chemical gases. In China, 7 million tons of organic volatiles are emitted into the atmosphere every year in the use of coatings. Therefore, the huge "influence" of VOCs on air pollution can be seen.
The impact of air pollution on human health is fatal. According to the latest statistics released by who, 7 million people died of "air pollution" in 2012, more than double the previous figure. It is equivalent to one out of every eight deaths in the world caused by air pollution.
2. Serious waste of resources
More than 50% of traditional coatings are organic solvents extracted from petroleum. In the process of film-forming, organic solvents will volatilize into the air, which causes a lot of waste of resources.
Experts pointed out that if a coating enterprise with a production capacity of 125000 tons is taken as an example, it will consume 200000 tons of oil every year, which is equivalent to the consumption of 268000 tons of coal per year. And this is only the data of an enterprise. If the oil consumption of coating production in the industry is accumulated every year, the total oil consumption will be huge.
3. Safety issues
VOCs are flammable and explosive gases, which have great potential safety risks in the process of production and use. Like a hidden bomb around people, VOCs will threaten the safety of users at any time. At present, VOCs have been listed in the environmental management registration of hazardous chemicals.
In the past many reports, the explosion cases of traditional coatings in the use and storage process are numerous, and the tragic cases of injury and death are worrying.
4. Fatal "occupational diseases"
Experts believe that the life safety of workers exposed to high concentrations of VOCs is even more worrying. The working environment of workers is like a dangerous "minefield". There are a lot of toxic volatile substances in coatings, including formaldehyde, benzene, xylene, etc. Some research reports hold that: long term exposure to organic compounds may lead to fatigue, memory loss and inattention; in severe cases, persistent personality and emotional changes such as fatigue, emotional instability, decline of self-control and autonomy will occur; and even more serious, mental impairment, dementia and loss of work ability will occur. Long term repeated exposure to low concentrations of benzene can cause chronic poisoning and damage the nervous system and hematopoietic system. At the same time, it will also affect the growth and development of the next generation, such as causing birth defects. However, these serious symptoms in the eyes of outsiders are only "mild symptoms" of occupational diseases in the eyes of workers.
When working in the workshop, workers must wear special masks to reduce the inhalation of organic volatiles in the production process. However, for people who have been engaged in production for a long time, wearing masks has limited effect on preventing inhalation of toxic substances. It is common for workers to faint and vomit during operation. However, most of the workers who have been engaged in coating production for many years suffer from occupational diseases and even lead to permanent disability of some workers.
3、 The best substitute for coating in steel structure factory
The best substitute for traditional coatings is new environmental protection coatings, such as waterborne industrial coatings. Water based coatings all use water as diluent, no organic solvent, no organic solvent, no benzene, toluene, xylene, formaldehyde, free TDI toxic heavy metals, non-toxic, no pungent smell, harmless to human body, no pollution to the environment, the paint film is plump, transparent, flexible, water-resistant, wear-resistant, aging resistant, yellowing resistant, fast drying, easy to use.
4、 Performance advantages of waterborne industrial coatings
1. Fast drying
Starting from the innovative film-forming mechanism, water-borne industrial coating adopts new water-borne polymer and advanced production process, optimizes the crosslinking density of the film, improves the mechanical properties and weather resistance of the coating film, and discards the incomplete matching process currently used abroad, which not only realizes the one-time coating of water-borne high gloss color losing finish (no need to spray varnish again), The drying process can be simplified by reducing the operation process, saving energy and reducing consumption. The drying process can be dried at 75 ℃ for 20 minutes and can also be dried at room temperature.
2. Simple construction
No need to use special spraying tools, ordinary spray gun can be used for high-quality construction. Water is used as solvent from primer to topcoat, which simplifies the cleaning process of equipment and tools. The use of water as cleaning agent reduces the consumption of organic solvents, eliminates the pollution of surrounding environment caused by excessive use of benzene containing solvents, and greatly reduces the occurrence of occupational diseases, which is more conducive to the health of front-line operators.
3. Energy saving and consumption reduction
Water based industrial coatings, from primer to topcoat, all use water as diluent and cleaning agent, which fundamentally eliminates the storage consumption and use of organic solvents.
Water based industrial coatings do not contain xylene, butyl acetate and other harmful components, reducing environmental pollution.
Water based industrial coatings improve the drying conditions, reduce energy consumption, reduce the requirements for equipment, and reduce a series of work requirements such as safety production, fire prevention measures and so on.
