Waterless Printing Successfully Breaks Through The Bottleneck Of Printing And Dyeing&Nbsp; Overcome Printing Problems Of Natural Fabrics

China is a large textile production country with a tradition of Printing and dyeing industry Dyeing fabrics with water as the medium, due to the incompleteness of the aqueous phase reaction, there are a lot of chemical pollutants in the water. Data shows that at present, every 10000 meters of printed fabric produced by the printing and dyeing industry can pollute 300 to 400 cubic meters of water. Due to the difficulty and large investment in wastewater treatment technology, textile printing and dyeing wastewater treatment has always been a bottleneck for the sustainable development of the textile industry.

In recent years, the emergence of waterless printing, especially transfer printing technology, seems to bring a glimmer of light to solve the problem of zero sewage discharge in the printing and dyeing industry. Because transfer printing belongs to gas phase reaction and does not rely on water as the medium, there is no or few wastewater discharge problems. However, transfer Printing technology Its "fatal injury" is that it cannot be used for natural fiber fabrics. In the context of people's pursuit of returning to nature, the limitations of transfer printing hinder its further development. Recently, Tong Xiang, an engineer of Xuebao Fine Chemical Research Institute, found the key to solve the problem that transfer printing cannot print natural fabrics. Recently, the reporter interviewed Tong Xiang.

Reporter: In order to solve the transfer printing problem of natural fiber fabrics, a lot of research has been done at home and abroad in the past decade. The main problem is that natural fibers are not easy to "retain" disperse dyes. How did you solve it?

Tong Xiang: Many people at home and abroad have used the methods of modification, bridging and coating Natural fiber The attempt of sublimation transfer printing was abandoned because of poor coloring rate, migration (migration) and color fastness. Therefore, how to solve the problems of coloring rate, color fastness and migration will be the key to success. The "pretreatment agent" developed by us has expanded the scope of transfer printing. The current technology of synthetic fiber, artificial fiber and natural fiber is "all in one".

Reporter: How did you solve the problem?

Tong Xiang: The "pretreatment agent" developed by us is a new way to solve the problem that natural fibers such as wool and silk cannot be heat transferred printed. We call it "natural fiber transfer printing color fixing regulator" and "bridging agent". It builds a "bridge" between natural fibers and dyes. Through chemical bond and fiber combination, it realizes copolymerization and cross-linking of macromolecular functional groups, thus solving the technical problem of transfer printing of natural fibers.

Reporter: Sublimation transfer printing uses heating method to make the heated disperse dye molecules diffuse into the fabric to achieve the purpose of coloring. This has been achieved on polyester. But how to solve the problem of thermal carbonization when it is used on natural fiber fabrics?

Tong Xiang: In order to adapt to the anhydrous printing and dyeing process, we made the "pretreatment agent" into a water based dispersion system (emulsion). It is a polyelectrolyte (polymer electrolyte) multi clock multi monomer copolymer, which belongs to the reactive functional material in functional polymer materials. Its reactivity plays a role through copolymerization and cross-linking of polymer functional groups. In sublimation transfer printing with wool and silk, chemical bond reaction takes place between auxiliaries and fiber surface, and cross-linking is formed between polymers. The ratio of two monomers is adjusted to improve the heat resistance of the fabric.

Reporter: How many kinds of "pretreatment agents" have you developed at present? How about the output?

Tong Xiang: In May 2006, with the support of Jiangsu Snow Leopard Daily Chemical Co., Ltd., we established the "Research Group of Natural Fiber Transfer Printing Color Fixing Regulator". At present, we have developed 81 formulations of "pretreatment agent", which can provide products according to different requirements of customers, with an annual output of more than 3600 tons. At present, we are expanding the production scale, and will form a production capacity of 30000 tons/year in May 2010.

Reporter: What are your plans for the next step?

Tong Xiang: On the basis of this research, we will further expand the application scope of "pretreatment agent". For example, the attempt of transfer printing on leather and wood has a broad market prospect.

Using zero emission sublimation transfer printing (waterless printing) to gradually replace traditional water printing and gradually transfer from wet printing to dry printing is a complex system engineering, involving multiple fields and disciplines. It needs to comprehensively consider many factors such as materials, processes, equipment, and national industrial policy guidance. However, this will undoubtedly become the development direction of the printing and dyeing industry. The attempt of the research group of Xuebao Fine Chemical Research Institute should be taken seriously. It is understood that this research is entirely based on their own exploration, and in their words, "blind people climb mountains", step by step to the top of the mountain. In the face of this innovative technology, the only thing we need to do is to encourage them to continue their career, so that transfer printing can be perfect sublimation.