Study on the dyeing process of polylactic acid spunbond nonwoven fabric with low temperature disperse dye

Polylactic acid spunbond non-woven fabric is a new type of material that can be made from renewable resources (such as corn starch, etc.). With the increasing awareness of human beings to protect the earth's environment, more attention is paid to the research and development of environmental protection technology and environmental protection products. Biodegradable polylactic acid will have more and more extensive application prospects in non-woven fabrics. At present, the domestically developed polylactic acid non-woven fabrics include needle punching, spunlace, spunbond, meltblown, thermal bonding and other products, but there are relatively many studies on dyeing them. Polylactic acid spunbond non-woven fabric is a product formed by polymer direct spunbond filaments through hot rolling and reinforcement. The main structure is still in the form of fibers, so its dyeing performance is the same as that of polylactic acid fibers. Polylactic acid fibers are mainly dyed with disperse dyes. In this paper, low-temperature disperse dyes are used to dye polylactic acid spunbond non-woven fabrics under high temperature and high pressure conditions. The focus is on the effects of dyeing temperature, holding time, dyeing pH, and auxiliaries on the performance depth (K/S) and strength. . Conclusion (1) The increase of dyeing temperature and pH value of dyeing solution has a great influence on the tearing strength of polylactic acid spunbond nonwoven fabric. When dyeing with low-temperature disperse dye (disperse blue 2BLN), the temperature and pH value should be strictly controlled . The actual pH value during dyeing should be controlled at about 5, and the temperature should be 110℃. (2) When the dyeing temperature is lower than 70℃, the amount of disperse dye uptake is less, and when the dyeing temperature is higher than 80℃, the dyeing rate increases obviously, reaching a higher K/S value at 110℃. During the heating process, the heating rate must be strictly controlled after the temperature rises to 80°C to obtain better level dyeing properties and ensure dyeing quality. (3) The variety of auxiliaries affects the dyeing of polylactic acid spunbond non-woven fabrics with disperse dyes. Appropriate auxiliaries can be added during dyeing to improve dye uptake and leveling. (4) Polylactic acid spunbond non-woven fabrics dyed with low-temperature disperse dyes can basically reach the dyeing balance when kept at 110°C for 20 minutes, and the actual holding time can be controlled at about 20 minutes.