Environmental sizing requires urgent policy encouragement

Business Club July 19 In 1997, for the textile sizing "less use, no PVA" is a starting point. After more than ten years of appeal and active promotion, with the increasing emphasis on environmental pollution from all walks of life, the industry has reached consensus on the use of PVA for textile sizing. With the enhancement of people’s environmental awareness, the introduction of the national energy conservation and emission reduction policy, and the restriction on the import of PVA-containing pulp fabrics in developed regions such as Europe, the problem of no-PVA sizing has gradually moved from an ideal state into the development reality of the company.

However, as pointed out by Gao Weidong, vice president of Jiangnan University and director of the Textile Sizing Professional Committee, due to the existence of various constraints, there is still a long way to go to achieve PVA-free sizing. It is still a long way to go further to promote “green sizing” on the basis of “no PVA sizing”. Promote environmental protection sizing to enter the critical period.

The target of cost factors leading companies to choose “no PVA sizing” has been proposed for more than ten years. Although the proportion of PVA slurry is gradually decreasing, it is estimated that the annual amount of PVA in textile sizing is still as high as 150,000 to 200,000. Ton. At the 2011 National Slurry and Sizing Technology Conference, corporate representatives still questioned the complete absence of PVA. What are the main reasons for promoting environmental sizing resistance?

Wang Hongtao, deputy general manager of Luoyang Baima Group Co., Ltd. believes that the main reason is that upstream and downstream companies do not pay enough attention to environmental protection. They have not yet realized that environmental protection sizing will determine the survival of enterprises and affect the sustainable development of the industry.

Zhu Bunana, president of the China Cotton Textile Industry Association, believes that at present, weaving companies are simply pursuing reductions in slurry costs and pursuing improvements in the efficiency of looms. Printing and dyeing companies only pay attention to the raw material costs for purchasing grey fabrics and do not attach importance to the cost of sewage treatment, resulting in non-degradable pulps. Occupy the market. In the absence of PVA environmental protection sizing has not implemented supervision and assessment, the cost of slurry is still a key factor in determining the choice of companies or to abandon the use of PVA.

The reporter learned that since the beginning of this year, PVA prices have fluctuate drastically. When the price of PVA rose, the cost of sizing the company after using PVA-free pulp decreased, and the enthusiasm of some companies increased; once the price of PVA fell, the low-cost benefits drove some companies to return to PVA. In this regard, Wang Hongtao believes that companies must recognize that environmental protection sizing is not a cost issue but a problem that determines the future survival of enterprises. They must plan ahead and act as soon as possible.

Xiao Wei, general manager of Jiangsu Yulon Textile Group Jingjiang Yufu Textile Co., Ltd., said that currently the implementation of PVA-free sizing by cotton textile companies depends entirely on the social responsibility of the corporate leaders themselves, while the risk of producing difficult-to-produce varieties without PVA sizing is still present. It is borne by cotton textile companies. Especially in the current difficult textile situation, cotton textile companies have not received the benefit of printing and dyeing companies to reduce desizing costs and reduce carbon emissions. In addition, when weaving companies use green pulp, some printing and dyeing companies do not understand it and did not use the corresponding process in the desizing process.

Due to the lack of attention paid by enterprises to environmental protection sizing, coupled with the current lack of incentives and corresponding restrictions on the use of PVA sizing, there is a lack of market momentum for passive sizing. Many experts recommend that the government introduce relevant policies to reward environmental protection sizing pioneers and pass environmental protection taxes to limit the use of non-environmental slurry such as PVA.

Who can perfectly replace PVA

PVA has been proven on the sizing process for many years and is a good sizing material. According to experts, PVA has excellent film forming properties, adhesive properties, and compatibility with other slurries. It has been a good sizing agent for yarns used in high-count, high-density pure cotton fabrics for many years. Especially in the T/C sizing, its performance is unmatched by other slurry so far. Now, 40 pieces of pure cotton and the following, polyester-cotton ordinary products, etc. have basically been realized without PVA sizing, and product quality is stable. However, high cotton, high density, high tightness, and polyester/cotton special products cannot achieve complete PVA sizing.

The use of slurry is the basis for guaranteeing the effect of sizing. In order to further promote the process of sizing without PVA, all companies are focusing on the development and application of new sizing. The so-called substitute PVA slurry in the market has a wide range of types and application effects. However, environmental protection slurry with high technical content, excellent performance, high reliability, and industrial replacement of PVA is difficult to meet and cannot be satisfied. Textile companies' needs. At the annual sizing and pulping technology annual meeting, textile companies hope to have more green slurry available for screening. In addition to PVA, modified starches and polypropylene-based slurries are the most widely used slurries in textile companies. Modified starch has good biodegradability, can form a certain strength of the serous membrane, has a certain penetration and adhesion to the yarn, and has the most amount, but the starch film has a hard and brittle film. After application and practice, although the sizing performance of modified starch slurry is continuously increasing, there are still problems such as aged gel in the slurry. Acrylic slurries have the characteristics of strong film strength, appressed hairiness, good permeability, and easy desizing, but due to their strong hygroscopicity and high price, they are generally used as auxiliary slurries for sizing.

According to Shi Bosheng, chief engineer of Tianhua Enterprise Development (Suzhou) Co., Ltd., in recent years, although significant progress has been made in the development of new slurries that replace PVA, there have also been some tendency problems. The most prominent issue is the use of non-environmentally friendly slurries to replace PVA, which is contrary to promoting the use of sizing without the fundamental purpose of PVA—protecting the environment. He reminded everyone that terephthalic acid degraded from polyester slurries is not only poorly degradable but also toxic. PVA itself is non-toxic, so polyester slurry is less environmentally friendly than PVA. At present, the production volume of polyester pulp is increasing, and new resistance has been formed for the implementation of environmental protection sizing.

Environmental protection sizing is inseparable from the purpose of supporting the sizing process mainly to meet the weavability of the yarn in the weaving process. The effect of sizing depends not only on the size but also on the quality of the yarn, sizing equipment, sizing technology, and employee operating techniques. Many companies have shared their experiences and stated that only by following the principles of similar compatibility of fiber and pulp and green environmental protection principles, they should select pulp, be familiar with the properties of pulp, and control the ratio of soaking and coating, according to the quality and quality of yarn. The matching of the slurry is optimized to ensure the stability of the sizing effect.

Shandong Demian Co., Ltd. Li Xinshun said that how to use no or less PVA without affecting the weavability of the yarn does not affect the cloth machine efficiency and the quality of the cloth. This is a systematic problem, only from the pulp company research. It is not enough to replace PVA's environmental protection slurry. It is also necessary to start with raw materials, yarn quality, production equipment, and production processes.

With the increase in the product quality of yarns and fabrics, the technical difficulty of sizing increases. For example, in recent years, the variety of yarns has varied, and the promotion of multi-fiber blending, the development of high-branch cotton yarns, the emergence of ultra-conventional yarns, the ratio of polyester yarns and cotton blends have increased the difficulty of sizing technology; With the development of weaving to a shuttleless, high-speed, and large-tensile development, weaving varieties have a high degree of tightness, a large width, and an increased difficulty in weaving. New requirements have been put forward for the slurry and sizing technologies.

After adopting the environmental protection slurry, the film forming property of the slurry, the strength of the slurry film, and the wear resistance must be taken into account. Therefore, after removing the PVA, the sizing effect can reach the weaving requirements and be improved. This is a required technology. Innovative system technology engineering.

Xiao Wei said that since the 1960s, China began to use PVA in large quantities, and it has been more than 40 years since now. With PVA sizing, textile production has formed an intrinsic mode in management, operation, production processes, and equipment. With less or no PVA, it took more than a decade, so there must be breakthroughs in technology, management, equipment, and operations, adapting to PVA-free production, and expediting the exploration of new production models without PVA sizing.

In addition, the so-called "environmental sizing" on the one hand is that sizing must use environmentally friendly sizing, and on the other hand sizing must also be environmentally friendly and low-carbon. From the perspective of the exchange of slurry and sizing technology in the country in recent years, everyone's focus is still more on PVA-free slurries. Research on new process technologies such as environmental sizing and low-temperature sizing has just begun. Therefore, Wang Yuqi, secretary-general of the China Cotton Textile Industry Association, also appealed at the meeting to increase research and exploration for the production technology that does not use PVA's environmental protection sizing, to get rid of the shackles of the original PVA sizing conservative process, and to boldly innovate and practice energy-saving and environmentally friendly sizing. New technologies and new processes.