Blue Sky Defense War Typical Cases | Spraying Production Line Water-based Substitution Project Promotes Green Environmental Protection Development of Enterprises

In view of the treatment of organic waste gas from the coating process in the bicycle industry, the two production lines of Zhejiang Deqing Jiusheng Vehicle Industry Co., Ltd. all use water-based industrial paint instead of oil-based paint, which solves the problem of VOCs emission from the source, reducing VOCs by about 100 tons per year and promoting the green and environmental protection development of enterprises.

Project Overview

Zhejiang Deqing Jiusheng Vehicle Industry Co., Ltd. is a national high-tech export-oriented enterprise that produces all kinds of bicycles and children's bicycles. It has formed an annual production capacity of 2 million vehicles. The company has 2 surface spraying production lines for bicycle frame forks, which are the main source of VOCs exhaust gas. The painting links of the frame, front fork, handlebar, chain cover, etc. are treated with solvent-based antirust paint. The waste gas generated in the production process needs to go through water spraying, filter cotton filter screen to remove paint mist and then enter UV photolysis treatment and other multiple treatments to meet the emission standards. When the treatment effect is not good, it is easy to cause certain impact on the environment.

In 2017, the company actively responded to the national call, and through continuous research and testing by technicians, it was determined to use water-based acrylic resin industrial paint to replace solvent-based paint. The painting process is carried out in the full-automatic painting room, and the lower half of the painting line is equipped with a manual painting process, which not only reduces the escape of paint mist, but also improves the painting efficiency. The water-based replacement work of this project has greatly reduced the generation of VOCs and made a positive contribution to environmental protection.

automatic spraying line

water-based paint

Highlights of work

project key technology

The use of water-based acrylic paint instead of oil-based paint reduces the generation of VOCs at the source, and the quality of products produced under certain production conditions is guaranteed, and certain economic benefits are obtained while doing a good job in environmental protection.

Project innovation point

The application of water-based paint is completed by means of closed automatic paint spraying room and manual paint repair, which not only prevents the paint mist from escaping in the process, but also makes it economical and efficient.

Fully enclosed automatic spray booth

Artificial paint repair room

Technical and economic indicators

1. Before the water-based substitution, the paint consumption of the enterprise was 140t/a, and the thinner accounted for about 40%. In 2017, the enterprise replaced two spraying production lines with water-based paint, and 100 was replaced with environmentally friendly water-based paint. The environmental protection composition ratio of water-based paint is: ① water-based acrylic resin 65-70%;② 8-10% of water-based silver paste; ③ 10-15% of deionized water; ④ 5-7% of water-based additives. The diluent is ordinary tap water (completely removed the use of the original diluent xylene), and the VOCs content is greatly reduced.

2. Water-based paint uses water as diluent. 70%-90% of its composition is water. It does not contain toxic organic solvents such as benzene and halogenated hydrocarbons and heavy metal compounds such as formaldehyde, lead and chromium. It does not need curing agent and has no volatilization problem of free TDI (toluene diisocyanate). Therefore, it can greatly reduce VOCs emission from the source and ensure the physical and mental health of employees. It is a safe and low-pollution environment-friendly paint.

3, water-based paint superior performance, easy to operate, spraying process is not easy to appear bubbles, particles and other common problems of oil paint, and the film is plump, crystal clear, good flexibility and has fast drying, water resistance, wear resistance, aging resistance, yellowing and other characteristics, making the product lasting as new.

Social and environmental benefits

After the source substitution, the annual reduction of VOCs is about 100 tons, which greatly reduces the generation of VOCs from the source in line with the development concept of green environmental protection.

2. Water-based paint is not flammable and has no special requirements for storage, which reduces the risk factors and troubles in the storage process of the enterprise. Benzene, xylene, natural water, etc. are highly flammable items, and there are potential safety hazards during storage, while water-based paint is safe and non-flammable, which can avoid such storage safety hazards.

3, oil paint to water-based paint not only from the source to fundamentally solve the problem of VOCs emissions, while the investment in environmental protection facilities and daily environmental management operating costs are significantly reduced. Compared with the original oil paint, the comprehensive cost can be reduced by about 20%, the cost can be saved by 4 million yuan in one year, and the environmental protection brand degree of the product is improved, and the win-win situation of economic and environmental benefits is realized.

In view of the treatment of organic waste gas in the coating process of bicycle industry, Zhejiang Deqing Jiusheng Vehicle Industry Co., Ltd. has overcome the technical problem of water-based substitution, comprehensively updated the raw and auxiliary materials, and changed 100 percent of the spraying production line to water-based coating, thus achieving a win-win situation of economic and environmental benefits. This case is applicable to the treatment of organic waste gas in the metal surface spraying industry and can be vigorously promoted in this industry.