Enzymatic treatment of flax fibre at the roving stage for production of wet-spun yarn

In the past few years, an acute shortage of good quality flax has compelled wet-spinners to seek alternative process steps for maintaining consistent quality of bleached yarns. The objective of the current investigation was to develop process recipes for the production of better quality yarn from lower grade fibre supplies. A laboratory method was developed to screen enzyme and chemical formulations, using hanks of fibre in the form of roving. The splitting of fibre, after treatments with ethylene diaminetetraacetic acid (EDTA) at 40 °C and two enzyme formulations containing, pectinases, xylanase and laccase at 40 °C was monitored by a tensiometer to assess tenacity and extension under load. The treatments were compared with an industry standard caustic boil (4% NaOH) treatment at 95 °C. The duration for all process conditions was 3 h. The selected treatments were scaled up in a twin pilot scale unit using rovings, followed by H2O2 bleaching and wet-spinning. The resulting yarns were evaluated for tenacity and regularity. The recommended process steps were pre-treatment of fibre with EDTA followed by sequential treatments of a mixture of pectinases and xylanase enzymes and H2O2 bleaching. The results of this investigation have shown that laccase enzyme can be used for roving treatment to improve yarn regularity.