The Production and Extraction of Flax-Fibre for Textile Fibres

Flax (Linum usitatissimum) is a bast fibre plant cultivated for the production of fibres, for use in a wide range of woven and non-woven end uses. Traditionally, the production of fibre from flax has focused on long fibres for use in the manufacture of linen yarns. However, short-fibre flax can also be produced and processed to be a 'cottonised' fibre for the production of textile yarns on cotton processing equipment. In the work described here, the production of a cotton compatible fibre from flax crops grown solely for a yield of short-fibres is evaluated and the performance of a novel 'picker' decortication and fibre cleaning pilot processing unit on fibre quality is measured. Short-fibre flax trials were established in the UK in 2006 and 2007 to assess the performance of short-fibre flax crops (cv. Agatha) as material for the production of cottonised fibre. The flax crops were retted using the stand-retting method with crop desiccation at mid-point flowering. After retting and harvesting, the crops were decorticated using a pilot decortication and fibre opening unit, to separate fibres from the woody core and foreign matter without damaging the fibre. The effect sowing density (450, 900, 1350 and 1800 seeds per m(2)) on crop yield and fibre quality (fibre fineness) was studied, while the effect of the decorticator on fibre separation and fibre sample cleanliness was also investigated. Short-fibre flax crops produced a straw yield of 6.3 t per ha in 2006, while in 2007 straw yields, varied from 5.0 to 6.8 t per ha with increasing sowing density. Fibre yields after processing through the pilot decortication and fibre opening unit were 1.6 t per ha in 2006 and ranged from 1.3 to 1.8 t per ha in 2007. After MDTA analysis of fibre this corresponds to a fibre yield of 25.4-26.2% of harvested straw.