China's textile dyeing and finishing industry has achieved rapid growth for many years. In.2008, more than more than 2000 printing and dyeing enterprises have been developed in China, and the total output of printing and dyeing cloth has reached 49 billion 433 million meters. Among them, the output of printing cloth accounts for about 45%. And the output of rotary screen printing has more than 2/3 of the total amount of printing. Rotary screen printing machine because of simple operation, low labor intensity, high production efficiency, wide adaptability, and is developing very quickly, at the same time, as the main consumption of rotary screen printing supplies a nickel net increases significantly. According to reports, the annual consumption of various specifications of nickel screen network in 500~600, the annual consumption of nickel metal about ten thousand tons. Because of the shortage of nickel ore resources, the cost of nickel network is also increasing.
First, the status of nickel mesh stripping and reuse
Round net costs accounted for a larger proportion in the round net printing costs, how to deal with a large number of idle after printing mesh, which can be repeatedly used, has been of concern for the printing and dyeing enterprises. By the importance of scientific research institutions.
In order to solve the recycling problem of waste nickel screen in printing and dyeing enterprises, the key is to do a good job of stripping, cleaning and reusing the nickel screen, but the former membrane cleaning technology is not ideal. There are some problems as follows:
1, removal of membrane cleaning is not thorough, after cleaning there are still clogging two times when using a mesh quality is not good;
2, both sides of the fence off the bulkhead in the process. The mouth swell deformation bulkhead on the second time to break off;
3, in the process of cleaning fence stripping nickel net diagentic, in the repeated use of the process for nickel net brittle lead off the net;
4, the use of liquid toxicity. Damage to the environment, the operator slightly careless, it will cause harm.
Many manufacturers fence cleaning degumming of one-sided pursuit of economic interests, only consider lowering stripping potion cost, use and membrane cleaning agent with sodium fluoride or sodium hypochlorite based cleaning mesh, this process is low processing cost. But there are more problems.
The cleaning process is as follows: the degumming solution fence into sodium fluoride, in high temperature above 90 DEG to boil for about an hour, the sodium fluoride penetration into the photosensitive film, and in alkaline conditions to soften, then in dilute sulfuric acid tank, produce hydrofluoric acid and sulfuric acid reaction, the hydrogen fluoride the photosensitive film swelling and peeling off the Internet. Sodium fluoride is a toxic chemical reagent is strong, has a great harm to the human body, long-term work in such an environment, easily lead to fluorosis, such as acromegaly. At the same time will bring some serious problems, such as: the formation of hydrogen fluoride sodium fluoride with dilute sulfuric acid reaction, net washing wastewater is high fluorine water, not mixed with other waste water into the biochemical pool. Once discharged into a sewage treatment system, not only does it cause serious pollution to water quality, but also hydrogen fluoride is a highly toxic bactericide. It kills biological bacteria in the biochemical pool, which can lead to paralysis of the biochemical system. In addition. Hydrogen fluoride is also very harmful to the sewage biochemical treatment unit.
Sodium hypochlorite and sodium fluoride removal membrane degumming principle is basically the same. Although not by sodium hypochlorite stripping high fluoride wastewater, sodium hypochlorite but highly toxic chlorine removal in membrane cleaning in the process of labor protection fence, improper operation personnel are easy to cause acute pulmonary emphysema. Within a short period of time can cause suffocation. A company in Shandong has had an accident in which the operator suffocated.
Two, environmental cleaning agent, membrane removal agent JJJ, 1 implementation of the application
After years of research and practice, the membrane cleaning agent has also been constantly updated and improved. At present, the market has a low toxicity, no corrosion (toxicity is not higher than the toxicity of industrial ethanol) new membrane sales. The use of the film release agent not only improves the efficiency and quality of the membrane cleaning, but also improves the working conditions of the membrane cleaning, and conforms to the policy orientation of the national circular economy.