Construction of a pilot plant for producing fine linen fibers for textiles

A newly built 200-L-pilot plant was used for testing a novel chemo-enzymatic process for producing fine flax fibers without the weather-associated risks of dew retting. Raw, green and decorticated flax fibers were placed inside trays in the tempered main tank of the pilot plant, where a vertically acting mechanism gently moved the parallel fiber bundles. The fibers were incubated in an alkaline bath, in a pectinolytic culture of Geobacillus thermoglucosidasius PB94A and in a peroxide-softener bath. Finally the fibers were dried, combed and hackled into a sliver that is ready for wet-spinning of linen yarns. A total of 140kg of raw fibers were treated in 40 different experiments in the pilot plant. The resolution of the raw fibers improved from 7.3 to 2.7±0.3 after the treatment. The fineness was enhanced from 37.4dtex to 11.1±1.2dtex. The proposed pilot-plant process produced constant-quality fibers and could be easily up-scaled.