How to achieve energy saving and emission reduction in dyeing and finishing

"Printing and dyeing counterparts work together to make energy-saving and emission reduction more effective." Under such a common premise, various new technologies for dyeing and finishing at the 4 New Conference were well communicated and promoted by the participants. The R&D and promotion of some key technologies, as well as the direct benefits brought about by energy saving and emission reduction, were urgently desired by the participants. The operability of these dyeing and finishing technologies has received great attention.

Moderator: Will the experts talk about what new technologies, new processes and new products are brought in this conference? What are the backgrounds for the research and development of these projects? What are the impacts on the current related fields?

Wang Xingnan: Shanghai Yuhui Chemical Co., Ltd. brought this time a “spraying and dyeing process”. Yuhui Chemical concluded that spraying the foam has no free moisture in the fabric fiber gap, which reduces the energy required for drying or steaming balance. The spray foam method causes the fabric to have very little free moisture and is free from hydrolyzed dyes in the free water before fixing. Foaming method makes it possible to use direct injection, no stripping, and no salt to promote dyeing. The spray foam method basically does not take into account the occurrence of the migration phenomenon in fabric dye liquor or chemical solution. Due to no roller rolling pressure, the foam style is full and the hairiness is not affected. At the same time, the fabric can quickly reach the fixing temperature in the fixing stage, and the fixing is sufficient. After fixing the reactive dyes, water washing is very easy because it is a salt-free dry fabric with very little floating color.

Mao Weimin: “The development of key process technology for low-temperature dyeing and finishing” is the main research project of Zhejiang Chuanhua Co., Ltd. Therefore, the focus of sustainable development in the printing and dyeing industry is to study the environmental protection processing technology of cotton fabrics. It is particularly important to select low-energy and low-pollution processing technologies while ensuring the processing results.

Wang Xiaojun: Jiangsu Demeco Chemical Industry Co., Ltd. brought "the impact of reactive dyes on reducing the cost of finishing." This study is aimed at improving the dye fastness of dyes by adding additives to improve the color fastness. The W-type reactive dyes manufactured by Demeco Chemicals Co., Ltd. are all dual-reactive dyes that effectively increase the reactivity with the fibers. At the same time, we add special auxiliaries in the manufacture of dyes to increase the reaction capacity between dyes and fiber molecules during dyeing, improve the fixing ability of dyes, reduce the production of hydrolyzed dyes, and improve the color fastness of dyed products.

Through experiments on the effects of additives on the fixation of coloration and color development, we have reached the following conclusions: First, the color of a washed water color. Additive B <conventional additive A <additive C. The second is the color depth of soaping water: conventional additive A<additive C<additive B>. The analysis of the results is: the lighter the color of one wash, the better the fixation rate. The deeper the soaping color, the better the cleaning float color effect.

Moderator: What are the characteristics and advantages of these technologies in relation to traditional processes and products?

Wang Xingnan: The traditional rolling-bake-rolling-steaming (active) advantage is the most economical for mass production. The product produced by this method has a very good surface effect, a high color yield, and does not have a great influence on light and chlorine bleach fastness, and also has good reproducibility. However, the disadvantages are high salt content and high salt content in the sewage. It is not suitable for fabrics that may produce high migration. The drying process takes a long time and the relative investment is relatively large. Chemical tanks are not easy to balance and require water seals for feeding.

Yuhui's patented foam fixing process, the rolling-bake process is the same as the traditional process. The concentration of the alkali agent is converted by the traditional padding chemical solution, without losing the fixing and alkaline conditions. After the fixing solution is applied, it is baked to 140 degrees to 150 degrees, and the interior of the fabric can be rapidly maintained at a fixing temperature of 55 to 70 degrees. The humidity of the puffing in the oven is brought in by the fabric itself without the need for steam supply.

Mao Weimin: The characteristics of low-temperature bleaching and bleaching process are as follows: The current international and domestic attention to the ecological environment is increasing. New processes such as energy saving, consumption reduction, environmental protection, and short-flow processes are inevitable trends in the development of pre-treatment processes. Production practice has proved that compared with the traditional process, the low-temperature bleaching and bleaching process is more flexible, and the process can be freely combined according to factors such as equipment and processing types, and the application scope is more extensive.

The low-temperature bleaching and bleaching process ensures high whiteness, while the fabric strength is not substantially damaged, and the oxygen drift hole is greatly reduced. After processing, the fabric feels soft and plump, showing a natural luster. Low-temperature drilling and bleaching process can save energy and reduce emissions, and reduce the overall cost. After calculation, the overall cost of the process is reduced by 12% compared with the conventional process, in which the steam cost is reduced by 56%.

Wang Xiaojun: dye dyeing synergistic additives can improve the color fastness and reduce the amount of finishing fixatives. The use of Demeco's reactive dyes eliminates or minimizes the use of fixing agents, which reduces the cost of the finishing process. Saving 10 kilograms per 10,000 meters saves about 500 yuan in fixing costs. W-type dyes are suitable for all dark colors and high fastness requirements.

Pickling soaping keeps the PH value of the fabric slightly acidic. Demeco's reactive dyes are particularly suitable for cotton printing cloths with added value-added functions. In combination with acidic detergents, the surface of the cloth after washing is less likely to float. The pH value is neutral or slightly acidic, which lays a stable foundation for the finishing of various additional functions. It can fully meet the requirements of fluorine-based waterproofing, anti-fouling and easy decontamination, and it is slightly acidic on the fabric surface, giving full play to the application of additional functions after finishing.

Reactive dye additives improve dark hand. In general, when the reactive dye is dyed black, it has a stiff hand after dyeing, an excessive increase in the dye concentration to achieve the depth of dyeing, and a large number of surface-dyed dyes not only reduce the color fastness, but also feel astringent. The application of reactive dye additives enhances the incorporation of dyes into the fibers and the formation of covalent bonds in the fibers, so that the cloth looks deeper in color, and can reduce the amount of dyes and improve the stiffness and astringency of some dark blue and black products after dyeing. Reduced the amount of softener used in the after-treatment. Calculated at a rate of 10kg per liter, the cost per 10,000 meters can be reduced by 100 yuan.

Moderator: What are the intuitive benefits of these technologies and processes for energy conservation and emission reduction? What technologies are currently irreplaceable?

Wang Xingnan: Our analysis of the wet-short steam E-CONTROL process (Menfuji and DyStar Intellectual Property) came to the conclusion that its advantage is the use of less chemical additives and does not require the use of salt. It is suitable for dyeing on rayon and cotton blended fabrics that are difficult for other processes. High color yield, good fabric surface effect, no chemical liquid padding, no urea, no effect on the fastness. However, its disadvantage is that the limitation of the reactive dyes is large, and it is difficult to simulate the conditions of the wet and short steaming process by the use of the Dydaramimarin dye, and the equipment is expensive and the process conditions are difficult to control.

Yuhui patented foam spray? The solid color process highlights the advantages. No need to use salt, because there is no need for additional dye balance, no dye chemical tank off, low liquid to apply chemical liquid, shorten the oven equilibration time so that the oven instead of steaming efficiency is higher.

As the amount of liquid brought into the oven by this technology is reduced, the energy consumption of the wet drying oven is minimal. The use of salt-free, non-free hydrolysis of water dyes, can reduce the pressure of the washing process. There is no liquid waste generated between batches of chemical liquids, and filtered mercerized alkali can also be used.

Mao Weimin: We encountered some problems in the development of new processes: Short process processes need to be formulated according to specific conditions, the scope of application of enzyme preparations is limited, new types of auxiliary agents need to be developed simultaneously with the process, and new technologies remain in the laboratory stage.

The key technology of low-temperature dyeing and finishing technology is good for energy conservation and emission reduction, and at the same time it reduces the overall cost. After calculation, the overall cost of the process is reduced by 12% compared with the conventional process, in which the steam cost is reduced by 56%.

Among them, the low-alkali dyeing process - reactive dyes LA series: Alkali fixation, soda consumption is only 1/8-1/20 of the traditional amount. With this process, the dyeing rate is low, the color is not easy to be dyed, the dye is less hydrolyzed, and the various fastnesses can be improved. At the same time can quickly dye, save time and safety. It is easy to operate, reduces costs, has good cleansing properties on the fabric, and has a low discharge of waste water. Excellent compatibility and dyeing stability ensure reproducibility and primary success rate.

Wang Xiaojun: The special dyes for cold-rolled reactors selected by Demeco from the W-type have relatively complete chromatograms and high adaptability. They are used by printing and dyeing plants, and feedback reflects good performance. The cold pad-batch dyeing process that can be applied to environmental protection and energy-saving methods, has excellent low-temperature dyeing performance, high fixation rate, excellent color stability, direct consistency of all varieties, strong alkali-type dyes, moderate affinity , can achieve high reproducibility of cold roll. Can meet the dyeing of thick fabrics, save energy and achieve the purpose of reducing consumption.

Can prevent the extractable dyes can improve the quality of printed products, with the continuous adjustment of the market printing products, flower pattern and popular style changes reactive dye anti-printing, printing products deeply concerned by consumers. Our company develops and develops a complete set of W-type pullable and preventable environmentally friendly reactive dyes, which is the first choice for anti-printing, pull-out printing, and sculpting and printing. The printing effect of high-grade fabrics cannot be replaced by direct printing.

High-performance salt-free P-type dyes have significant energy saving and consumption reduction effects. High performance dual reactive P-type dyes, used for white-white products on orders. Its excellent properties derive from the use of organic dye additives from Demeco dyes instead of inorganic salt fillers, which can effectively achieve high-fixation and low stain on white. Orange P-GN, red P-4B, and blue P-5R salt-free dyes are recommended. With the reduction of inorganic salt emissions in water, waste water can be degraded by the current sewage treatment process, meeting the requirements of low-carbon environmental protection.