Primarily Study on Splitting Ability of Scrap Leather of Shoe Manufacturing into Fiber Form Materials

Abstract

In this research, methods for dissociation of leather fibers from scrap leather pieces of shoe manufacturing were examined. The types of scrap used were cowhide tanned by chrome tanning which is popular in shoe making in Vietnam. Dissociation techniques used include: (1) dry crushing and mechanical methods using a hammer mill and (2) chemical pretreatment-assisted wet milling using NaOH and H2SO4 at varied concentrations and retention time. Experimental results showed that both types are able to dissociate into fiber form materials by the two different treatment methods. When dried crushing using the pretreatment in H2SO4 is applied, fibers with rough surfaces and high shrinkage capability tend to swell easier in length. Meanwhile, pretreatment with NaOH is only suitable under mild conditions and requires relatively low concentrations and short processing times. Grinding directly by hammer mill is best used for clean leather without chemical pretreatment. The results are helpful in determining appropriate processes in the reuse and recycling of leather materials. It is also a premise for the development of processes to be applied to transform scrap leather into materials for other industrial purposes.