The main substances harmful to the human body in paint include formaldehyde, benzene, TVOC, etc. TVOC stands for total volatile organic compounds, including benzene, toluene, p-xylene, etc. It is not only the precursor of PM2.5, but also the main component of photochemical pollution.
The outline of the “13th Five-Year Plan” clearly states that total emissions of volatile organic compounds will be controlled in key regions and key industries, and the total emissions nationwide will be reduced by more than 10%.
Key industries include petrochemicals, organic chemicals, surface coating, packaging, printing, etc.
One of the “Shenzhen Standards” (furniture category) led by the Shenzhen Furniture Industry Association – “Limited Standards for Hazardous Substances in Finished Furniture Products and Raw and Auxiliary Materials” has recently been Implemented after review and approval by the Shenzhen Municipal People’s Government. The “Shenzhen Standard” (furniture category) will be officially implemented from January 1, 2017. From May 1, 2017, the use of solvent-based coatings and solvent-based adhesives will be completely prohibited in Shenzhen.
What is solvent-based paint? Why is it banned? For consumers, how can they tell whether solvent-based paint is used on furniture? With these questions, the reporter interviewed relevant experts.
Why is solvent-based paint banned?
“Solvent-based coatings mainly contain harmful organic solvents.” Peng Yingdeng, a researcher at the National Urban Environmental Pollution Control Technology Research Center, said.
What are the organic solvents used in solvent-based paints? Why disable it? Zhang Ren, secretary-general of the Residential Decoration and Renovation Committee of the China Building Decoration Association, said that architectural coatings are divided into solvent-based coatings and water-based coatings based on different diluents. Solvent-based coatings are architectural coatings made with organic solvents as dispersion media, mostly using formaldehyde as diluent. They are currently the most widely used and mainstream coatings, and their main varieties are also called paints.
At present, the main type of coatings and adhesives used in the furniture industry is solvent-based, accounting for about 95%. Most of the diluents used in solvent-based coatings are toxic and harmful to the human body. In particular, solvent-based coatings will release toxic organic solvents during the curing process, which can cause chronic poisoning if inhaled by the human body for a long time.
In addition to affecting human health, organic solvents in solvent-based coatings can also have a negative impact on the environment. Peng Yingdeng explained: “The organic solvent volatilizes and becomes the precursor of atmospheric photochemical reactions, which is the main source of photochemical smog.” According to data released by the China Painting Industry Association, the total amount of VOCs emitted by the paint and coating industry into the atmosphere every year Approximately 4.3 million tons, of which paint accounts for approximately 98%. Banning the use of solvent-based paints can effectively reduce VOCs emissions in Shenzhen by about 40% and reduce the degree and scope of photochemical pollution.
Although solvent-based coatings are not friendly to the human body and the environment, due to their ability to provide a wide range of solubility, the polymer film-forming materials of solvent-based coatings have strong aging resistance , good adhesion, smooth coating, good wear resistance, acid resistance, water resistance and other properties. Therefore, solvent-based coatings are still widely used in many fields.
What should I use instead of solvent-based paint?
Since solvent-based paint has many shortcomings, what should be used to replace it? A new type of environmentally friendly paint, water-based paint, is expected to become a substitute for paint.
Zhang Ren said that water-based paint is a new high-tech material that is repolymerized by polymers and has zero formaldehyde and zero benzene. The essential difference between water-based paint and paint is that the solvent used in water-based paint is water, while paint uses organic solvents.
Peng Yingdeng told reporters: “Compared with paint, water-based paint does not contain organic solvents, so there is no VOCs emissions.” Therefore, compared with paint, water-based paint has low formaldehyde , low irritating odor, environmental protection and other characteristics, water-based paint is currently being promoted around the world. The usage rate of water-based paint in Western developed countries has reached more than 80%.
Data show that my country has an annual furniture consumption capacity of approximately 500 billion yuan, making it the world’s largest furniture consumer market. If all water-based paints are non-toxic, odorless, healthy and environmentally friendly, the air pollution problem caused by solvent-based paints will be completely solved, a large amount of VOCs will be reduced, and a positive impact will be had on human health and the environment. Zhang Ren pointed out: “The furniture industry should force the use of water-based paint and eliminate traditional paint.”
Although water-based paint is more environmentally friendly than paint, market awareness is not high. The relatively high cost and spraying process requirements hinder the market popularity of water-based paint. degree. The cost of water-based paint furniture is 30% to 50% higher than that of painted furniture. In addition, it is not only the replacement of paint, but also the transformation of production lines and product changes. It requires an investment of tens of millions of dollars and it will take at least two years to complete the entire transformation. Therefore, few businesses are willing to produce water-based paint furniture. At present, the market share of water-based paint furniture in my country is only 5%.
In order to promote environmentally friendly water-based paint, on July 1, 2015, Beijing officially implemented the “Air Pollutant Emission Standard for Wooden Furniture Manufacturing Industry” to promote the withdrawal of paint from the market and require 2017 Furniture manufacturing enterprises will be inspected and accepted in 2019 to reduce air pollutants and volatile matter. In 2017, the Shenzhen Municipal Human Settlements and Environment Commission will also focus on promoting the “oil-to-water” transformation of the furniture industry, increase support and inspections, and plan to introduce policies to provide financial support to enterprises, accelerate the application of water-based paint, and promote the “oil-to-water” transformation. ” and other environmentally friendly process developments.
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