GB981235A - Spinning of bast fibres - Google Patents

Abstract

Flax or hemp fibres are obtained by a process which includes, instead of biological retting, subjection of the straw, in the presence of water, to a temperature which is sufficiently high to cause hydrolysis of the material binding the fibre to the woody core to an extent which renders the latter readily separable by subsequent mechanical treatment. As described, harvested de-seeded flax is placed in a kier and water, which may include a wetting agent and be rendered mildly alkaline e.g. by addition of sodium carbonate, is added. The liquor with the water soluble matter which has been removed from the straw is withdrawn after one hour, the kier is scaled and the straw is subjected to saturated steam at superatmospheric pressure therein for forty minutes followed by drying with a circulation of hot air therethrough. The straw is removed and converted into rove by successive treatments of switching or breaking, hackling and drafting, and wound under low tension. The rove is bleached by boiling the wound bobbins in an alkaline solution for one hour, running off the liquor, rinsing, treating with bleaching liquor(s) and washing. The bobbins are mounted in the creel of a wet, controlled draft, spinning frame and the rove is spun into yarn which is then dried and rewound. The draft may be controlled by means of an apron system or an adjustable breast beam deflecting the rove from a direct path between the nips of the drafting rollers, Figs. 1 and 2 (not shown).