New "Carrier" For Printing Process

For any printing and dyeing enterprise, the printing process is in the whole process. printing and dyeing The primary position of links. The batik industry is also the same. In view of the characteristics of African cloth, the printing of batik industry is mainly printed on reactive dyes with pure cotton fabric. The largest amount of the printing is the "carrier" - paste, which is used to dye the fabric. Today, alginate paste has always been an important position in reactive dye printing. However, with the continuous depletion of world resources and the growing awareness of environmental protection, it is urgent to develop new types of paste which are more widely distributed and easy to degrade.

Recently, Qingdao Phoenix dyeing and Printing Co., Ltd. uses alginate, modified starch and Botany The new type of reactive printing paste has been successfully prepared by using seed glue as raw material. This technology not only improves the quality of the product, but also reduces the production cost. More importantly, the paste used in the product is an environmentally friendly product, which is the major trend of environmental protection production vigorously advocated by the printing and dyeing industry.

Reactive paste paste palm door

According to Shi Kun, engineer of Qingdao Phoenix dyeing and printing company, many manufacturers in China have tried to replace the sodium alginate with natural plant modified starch instead of active printing paste. However, the application rate is far less than that of alginate paste, and the rate of color loss is inferior to that of seaweed paste. Many manufacturers use natural paste to mix with organic or inorganic synthetic paste instead of traditional paste. Although the color yield has been improved, it is still a difficult problem. Therefore, developing new environmentally friendly reactive printing paste is an important topic for printing enterprises to survive and develop.

Obviously, paste has become an important part of printing paste. As printing paste, the paste should have a high paste ability. The chemical and dispersive state of the paste should be stable and suitable for rheological properties, adhesion, cohesion, low affinity for dyes and easy washing. There are many kinds of paste. Most of the paste used by most enterprises can be classified into the following categories: natural hydrophilic polymers, denaturant of natural hydrophilic polymers and synthetic hydrophilic polymers.

It is understood that reactive dye direct printing is currently used for purity. Cotton weaving The most commonly used technology. The reactive dye has the advantages of wide chromatography, good wet fastness, low cost, convenient printing and good uniformity, but it can react with the hydroxyl group in the raw sugar paste, thereby reducing the fixation rate of the dye, and making the original paste difficult to wash and hard to handle. Sodium alginate is an ideal paste. It has strong paste ability, good permeability, no reducibility and wide application range of pH. Each ring contains a carboxyl group, which is a hydrophilic organic substance. It can be ionized into negative ions and reacts with reactive dye pigments. It is not easy to react with reactive dyes. However, calcium ions in printing will form insoluble calcium alginate, and the secondary alcohol group on the ring will react with reactive dyes. Therefore, softened water should be used when using sea paste. In addition, a high degree of substitution of carboxymethyl starch, polyacrylic acid and other anionic synthetic paste can also be used as a reactive dye paste, the latter is also better than sodium alginate in the color dosage, but its electrolyte resistance is poor. For this reason, sodium alginate is usually used as raw paste in industry. Because alginate has been widely used in food industry, the price is increasing. Therefore, finding a substitute for sea paste to reduce the production cost is a research topic at home and abroad.

Looking for alternatives

Qingdao Phoenix printing and dyeing Co., Ltd. in the process analysis of new reactive printing paste, the fabric selected is 100% cotton fabric and yarn size of 24/24, and the paste is selected from seaweed glue, modified starch, natural plant seed glue and so on.

By analyzing the properties of paste, R & D personnel understand the merits and demerits of each paste, and lay the foundation for compounding to meet production needs and replace the paste used now. The new products developed can improve the quality of products, reduce costs, and save energy and reduce emissions. In addition, its application performance has reached the requirements of high paste rate, fine paste, good solubility, simple operation and so on. It is reported that the paste has good chemical stability, good compatibility with dye chemical additives, and is not easy to decay during storage. Its water holding capacity, rheology, thixotropy and PVID value can reach or surpass alginate paste and have good net penetration. Especially in high volume flat screen printing, it can achieve good printing effect with uniform block surface, high profile and smooth lines. In addition, the paste has good permeability, high color yield, rich color, good fastness and good debinding rate. After washing, the fabric feels soft and the washing wastewater is biodegradable, which can lighten the burden of sewage treatment.

After studying the ratio of printing and dyeing of various natural reactive printing paste, in addition to the characteristics of the paste itself, the best proportion is chosen for the printing proofing test, and the compound paste which is equivalent or surpassed with sodium alginate paste is selected.

The company carries on the hand feeling after printing and washing various paste. Analysis 。 Hand feeling is one of the most important properties of printed fabrics. Whether the texture of printed fabrics is hard or not is related to whether the paste has been washed or not. Therefore, the defuzzability of printing paste is further determined. After comparing the viscosity of each paste, the contrast of printing and color and the contrast of the hand prints after printing, it was found that the properties of seaweed gum were moderate, but the price was high. In order to ensure the quality of products and reduce the cost, the compound ratio should be controlled below 50%. Modified starch paste is high in color and cheap in price, but its viscosity is low. It also affects the handle of the fabric, so its compound ratio should be controlled below 50%. Tamarind gum is moderate in price and good in osmosis. Combined with the double-sided penetration of batik print, this paste can be added with a small amount of auxiliary, and the ratio can be controlled below 10%.

After a lot of experiments, the results showed that compared with the original seaweed paste, the new type of reactive printing paste which was compounded with the dosage of 30%~40%, modified starch dosage 40%~30%, tamarind gum 10% and assistant 10% ratio had higher viscosity than the original seaweed paste. The stability of the paste was slightly better than that of the original seaweed paste. After printing, the color of the printing paste was higher than that of the original seaweed paste. The impression after printing was similar to that of the original seaweed paste, and the cost was also lower than that of the original seaweed paste.