Plant Starch Instead Of PVA Cotton Enterprises To Expand Energy Saving And Emission Reduction Channels

At the seminar on the application of new cotton technology and new product development, experts attended the PVA technology. Experts generally believe that the key to the popularization of PVA free sizing technology is to choose the right new environmental paste. At present, made in China. New environmental protection slurry The various technical indicators have largely met the requirements of replacing PVA. Many key cotton spinning enterprises in China have also been widely promoted and applied. Some experts give positive comments to them.

　　 No PVA is advancing

Some experts in the industry say that the cotton spinning and dyeing industry has made great efforts to promote the technology of PVA free sizing. The current situation is that printing and dyeing enterprises are more active in it.

This is because no PVA sizing technology can reduce the cost of slurry and improve weaving efficiency, but the effect is not obvious. For the process of desizing, dyeing and finishing of the back road, the use of PVA slurry directly affects the printing and dyeing effect and sewage discharge. Many environmental policies also aim directly at printing and dyeing enterprises, resulting in greater pressure on them. In addition, after several decades of popularization and application, most cotton spinning enterprises have already had a mature PVA sizing process. Therefore, both the technicians and the truck drivers prefer to use PVA slurry to sizing the yarns.

Li Dezhi, executive deputy general manager of Cotton Textile Technology Co., Ltd., believes that no PVA sizing technology has three advantages. First of all, it is in line with the requirements of post finishing. No PVA sizing cloth is desizing easily, and the cost is relatively low, so that the cost of dyeing and finishing can be greatly reduced. The two is to reduce the cost of sewage treatment, especially for COD (chemical oxygen demand) and BOB (biochemical oxygen demand). Three, it is more suited to the needs of the market. Now developed countries have set up various kinds of developing countries. Trade barrier Some merchants from the US and Europe put forward the technology without PVA sizing directly. Therefore, the company has been actively looking for a new environment-friendly slurry that can replace PVA.

Cotton spinning enterprises, of course, know that there is no advantage of PVA sizing technology, but they are more concerned about whether the new environmental slurry can really replace PVA and make the sizing process meet the requirements of the latter. Lin Yuanjie, chairman of the company, thinks that the starch used in sizing before is hard and brittle and has poor ductility. Therefore, PVA must be added to improve the toughness and wear resistance of the film, and at the same time, the environmental protection pressure of cotton spinning enterprises is not large enough. Some enterprises are afraid to use PVA without sizing up.

Therefore, no PVA sizing technology should be a joint project promoted by the upstream textile and chemical industry, the cotton textile industry in the middle reaches and the downstream printing and dyeing industry.

Slurry breakthrough is the key.

In fact, after the vigorous development of the industry and the continuous exploration of enterprises, there is already a new type of environmental protection slurry that can replace PVA in a certain extent. The sizing technology without PVA has also been widely applied in many domestic enterprises, and achieved good results.

Zhao Zhihua, assistant general manager of the PVA group, thinks that there are many kinds of pulp to replace the PVA in the market. Generally, corn starch and potato starch are used as raw materials to develop high performance starch with better performance than the original single modified starch through two or more denaturation. Its adhesive properties, film properties, gel properties, sizing properties are better than the original single. Modified starch It provides a material basis for advancing the sizing technology without PVA. However, the properties of these high performance starch are very different. Some high performance starch also contains PVA and other unenvironment-friendly ingredients. Some high performance starch can not reach the full or most of the sizing performance of PVA. This requires enterprises to seriously analyze and test the performance of each product, and be familiar with the advantages and disadvantages of these products in order to make reasonable use.

As a pulp production enterprise, the company has put forward the proposal that you should join me in saving water. The CD-DF868 size of the company can be used for sizing 40S, 50S, 60S, 80S, 100S cotton, T/C, T/R, Rayon, Tencel and so on, completely replacing the PVA, thus improving the weaving efficiency and reducing the sizing cost of the cotton spinning enterprises. At present, the company's new environment-friendly slurry has been extended to the world. Many domestic cotton textile enterprises such as Lu Tai, Lufeng textile, Dasheng, cotton and China 3542 and more than 100 foreign enterprises such as China, Vietnam, China, Vietnam and so on have not used PVA in different varieties.

Lin Yuanjie said that the 3542 Chinese company used CD-DF868 slurry instead of the traditional PVA for sizing the pure cotton yarn of 80S (high density and wide width). The cost of the slurry was reduced by more than 15%. The efficiency of the 480rpm high-speed loom remained above 90%. For the pure cotton yarn sizing of 100S (high density and wide width), the efficiency of the high-speed air-jet loom remained above 90% when the slurry cost was reduced by more than 10%.

Now, some places require printing and dyeing enterprises online COD not more than 120 mg / L, and some places require no more than 80 mg / L. Lin Yuanjie said that the ratio of 5 day biochemical oxygen demand to chemical oxygen demand (BOD5/COD) of completely alcoholysis of PVA was 0.01. The larger the size of the pulp, the better. More than 0.3 can be considered as an environmentally friendly slurry. The BOD5/COD of oxidized starch is about 0.4, and the BOD5/COD of CD-DF868 BOD5/COD is about the same as that of oxidized starch. Therefore, there is no green barrier to export products from the pulp of cedar pulp to Europe or other countries.

Advantage is more than environmental protection.

Through the use of CD-DF series slurry, the Dasheng group promotes no PVA sizing. The slurry has changed from PVA to PVA. The usage of PVA decreased from 52% of the main size to 2.9%. The proportion of PVA used in the whole year was reduced by 94.4%, and PVA slurry was used less than 500 tons per year. Over the past 5 years, the practice of no PVA sizing has proved that most varieties of yarns can be carried out. No PVA sizing 。

Because of the absence of PVA, sizing yarn is easy to divide, and the regenerated hairiness is obviously reduced. The definition of loom openings is obviously improved, and the average efficiency of looms is over 92%. The average efficiency of loom is increased by 4% over the original loom efficiency with PVA as the main sizing agent, and the annual economic benefit is increased by about 4000000 yuan. The cost of slurry is reduced by 8%, and the cost of slurry is reduced by about 700000 yuan a year. The use of high pressure sizing has been promoted, the use of steam in cylinder drying has been reduced, the consumption of steam and other energy consumption has been reduced, and the appearance of slurry pulp has been reduced, which has almost eliminated the defects of slurry spots. Through the treatment of residual slurry cascade and washing tank wastewater, the discharge has met the requirements of local governments for environmental protection. Products also meet the requirements of printing and dyeing mill to reduce sewage discharge.

Zhao Zhihua said that the stability of yarn quality and quality directly affects the advancement of PVA free sizing technology. No PVA sizing is used in production. In addition to determining the sizing formula, it is necessary to cooperate with the PVA sizing process through strict management to ensure that the sizing equipment has a good running state, strictly operate according to the technological process, and establish a yarn quality feedback system at the same time.