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Detailed Description Of Printing Technology For Reactive Dyes Instead Of Sodium Alginate

2013/5/28 20:31:00 44

Printing And Dyeing Industry Printing And Dyeing Technology Printing And Dyeing Association Printing Technology

technical introduction 
Since p a < href= > //www.sjfzxm.com/news/index_c.asp > reactive dye > /a >, sodium alginate has been used as printing paste for reactive dyes at home and abroad. It does not react with reactive dyes, has a moderate amount of color and good paste removal, but also has poor rheological properties. However, alginate has caused a lot of pollution in the production process. Due to environmental protection requirements, the price of sodium alginate has not increased in recent years, resulting in higher printing costs. Therefore, both domestic and overseas are actively looking for alternatives to alginate. Many of them are mainly modified starch paste, modified cellulose paste and synthetic thickener. Although the single property is better than sodium alginate, it can not meet the comprehensive performance requirements of reactive printing paste. 
In view of the shortage of sodium alginate, P has developed various synthetic thickeners to replace sodium alginate, and has made some progress. However, both of them can not meet the comprehensive performance requirements of reactive dye printing, especially the property of degelling is obviously less than that of sodium alginate. 
 New thickener instead of sodium alginate is applied to reactive dye printing with the following characteristics: 
 1., it is easy to make pulping, low in dosage and strong in thickening ability. 
 2. with stable performance, no corruption and no APEO, it belongs to environmental protection products. 
 3., good leveling ability, strong water holding capacity, fine pattern and no infiltration. 
 4., the amount of dyestuff is high and the brightness is good, which can reduce the dosage of dyes and reduce the discharge of sewage. 
 5., compared with sodium alginate, it is easier to remove paste and less water to make the printed fabric feel softer. 
 technical principle 
 in view of the market demand for sodium alginate reactive dye < a href= "//www.sjfzxm.com/news/" > printing > /a > thickener demand, the company uses seed emulsion polymerization method, using acrylic acid, methacrylic acid, ethyl acrylate, twenty-two alkyl polyoxyethylene ether methacrylate, 2- acryl acyl -2 methyl sulfonic acid monomer to copolymerate, through polymerization reaction to produce sodium alginate reactive dye thickening agent. 
 1., the action mechanism 
 acrylic acid, methacrylic acid, ethyl acrylate, twenty-two alkyl polyoxyethylene ether methacrylate, 2- acryl -2 Methylpropane sulfonic acid monomer are copolymerized, wherein 2- acryl -2 Methylpropane sulfonic acid monomer can make the polymerization product have excellent water holding capacity. The twenty-two alkyl polyoxyethylene ether methacrylate monomer can make the polymer have hydrophobic association function. The polymer is mainly intramolecular association in dilute solution. When the concentration is greater than the critical association concentration, the super molecular structure with intermolecular association is formed, forming a network structure, increasing the volume of fluid mechanics, thereby exhibiting good thickening effect. Especially in the presence of electrolytes (dyes), hydrophobic association is further strengthened. It also shows that the viscosity decreases under strong shear, and the association of new hydrophobic groups can form from low shear to form a high viscosity fluid. It has good thixotropy and is more suitable for printing circular screen and flat screen printing. The product has excellent performance, easy operation and low cost. It has the characteristics of thickening and associating performance, good water retention, clear print product profile, good desizing, soft handle and simple production process. The printing paste made of 4% of the product has good thixotropic properties. The circular printing is not towed, it is bright and colourful, the color is high, the water retention is good, the desizing is easy, the handle is soft, and the printed pattern is more complete and plentiful. 
 2. synthesis process 
 2.1 the selection of process route 
 on the synthetic route, the requirements for printing thickeners of reactive dyes instead of alginate were designed accordingly. 
 2.2 initiator selection 
 initiator is the power source of polymerization. In the process of polymerization, ammonium persulfate alone is used to initiate the system. The initial input is 20%, and the remaining 80% are continuously added. In the polymerization stage, the initiator is quantitatively decomposed according to its half-life, and the continuous addition of the remaining 80% parts can keep the reaction rate steady, speed up the reaction and shorten the reaction time. 
 2.3 water selection 
 the requirement for water is similar to that of general emulsion polymerization. There are strict requirements for heavy metal ions in water. Therefore, softened water should be chosen and the hardness of water is below 50PPM. 
 2.4 temperature selection 
 theoretically, the higher the reaction temperature, the faster the reaction rate. However, if the temperature is too high, it will increase the gel content of the system, resulting in difficulty in discharging. If the temperature is too low, the reaction time will be prolonged. After several tests, it is proved that 80~85 C is suitable. 
 2.5 monomer selection 
 to provide a product that has strong thickening, strong water retention, clear print, good desizing, soft handle and simple production process, through experiments, acrylic acid, methacrylic acid, ethyl acrylate, twenty-two alkyl polyoxyethylene ether methacrylate, 2- acryl -2 methyl sulfonic acid monomer are copolymerized to produce an environmental protection instead of sodium alginate reactive dye thickening agent. 
 2.6, time selection 
 through a large number of theoretical discussions and experimental summarization, the polymerization time is 3~4 hours. 
 2.7 key equipment 
 pre emulsion kettle, multi-function reaction kettle, speed regulating motor and circular pump. 
 technical key and innovation point 
 technical key: the seed emulsion polymerization method is used to copolymerize acrylic acid, methacrylic acid, ethyl acrylate, twenty-two alkyl polyoxyethylene ether methacrylate and 2- acryl -2 methyl sulfonic acid monomer, wherein 2- acryl -2 Methylpropane sulfonic acid monomer can make the polymerization product have excellent water holding property. The alkoxy polyethylene glycol methacrylate monomer can make the polymer have excellent thickening association effect, and produces reactive printing thickener instead of sodium alginate. 
 Innovation: using 2- acryl -2 Methylpropane sulfonic acid monomer can make the polymerization product have very little dosage and excellent water holding capacity. The twenty-two alkyl polyoxyethylene ether methacrylate can make the polymerization product have excellent Association thickening ability, good thixotropy and soft handle, and make the synthetic thickener achieve or even exceed the sodium alginate paste removal performance. 
 application scope 
 pure cotton woven fabric, < a href= "//www.sjfzxm.com" > knitted fabric < /a >, towel coated reactive dye < a href= "//www.sjfzxm.com" > printing process < /a >. 
 energy saving and emission reduction effect 
 compared with sodium alginate, the amount of reactive dye can be reduced by 5%~15%. When compared with the synthetic thickener, the water consumption can be reduced by 30%~40% and the steam consumption will be reduced by 20%~30% when the same degelling rate is achieved. The softness finishing can achieve the same handle and reduce the softener dosage 15%~30%.