Abstract: In this paper, a new combined process that consists of UV-freezing-heating, enzyme-treatment and HTHP treatment was adopted for the degumming of hemp fiber, and the influence of different process conditions on residual gum rate and mechanical property was investigated. Hemp fibers before and after degumming were characterized by using SEM, FTIR and TG, the changes of overall performance and structure and chemical composition before and after degumming of hemp fiber were analyzed. It showed that the lignin content reduced to 0.71% from 14.13%, the residual gum rate reduced to 2.26% from 43.12%.The fiber has smooth surface, increased whiteness, reduced diameter but improved evenness as well as better mechanical property, compliance and thermal stability. . Chemical reagent dosage has reduced by about 1/3, which means energy conservation and emissions reduction.

Key words: hemp fiber; HTHP; degumming; residual gum rate