超声波对原位树脂鞣制过程的影响研究

Influence of Ultrasonic on Melamine- formaldehyde Resin via In- situ Tanning

实验对比了在有无超声波辅助作用下,三聚氰胺原位树脂鞣制过程中的反应时间、反应温度、鞣制效果以及胚革和废液中游离甲醛含量的区别,并对影响结果进行了探讨。结果表明,在超声波作用下,浴液温度随超声波作用时间的增加不断升高,鞣制过程中可利用其热效应控制浴液温度;超声作用可以促进皮化材料的渗透与结合,使鞣制得到胚革的湿热稳定性提高,在保证鞣制效果基本不变的前提下,超声波辅助作用可以有效缩短鞣制时间,提高鞣制效率。同时,有超声波作用的鞣革废液中游离甲醛含量由原来的53.7 g/kg降低到5.0 g/kg,并且随超声时间的增加,游离甲醛含量逐渐减少;胚革中游离甲醛含量由147.9 mg/kg降低到71.3 mg/kg,达到了国家标准。

Tanned by melamine- formaldehyde resin via in- situ polycondensation. The ultrasonic action was employed and the influence of reaction time,reaction temperature,tanning performance and the free formaldehyde content in waste liquor during the tanning process were investigated,by comparing the leather tanned with ultrasonic auxiliary or not. The results indicate that the temperature of aqueous solution increased with the rising of ultrasonic action time,which would be useful to temperature- control during the tanning process. Moreover,with an action of ultrasonic,the combination between tanning agents and gelatin is stronger than control,so that the hydrothermal stability of gelatin was improved in a relatively short period of time. At the same time,the free formaldehyde content in the tanning waste liquid decreased from 53. 7 g / kg to 5. 0 g / kg. Ultrasonic plays a role in promoting the penetration and combination of leather chemicals,effectively shorting the tanning time thus to improve the tanning efficiency and protect the environment from the pollution by reducing the content of free formaldehyde in the tanned leather and wastewater.