Roller Force
Mechanical pressure applied by a heavy steel cylinder operating within a flax drawing frame compresses plant slivers to consolidate parallel fibres before roving takes place. The draft roller mechanism operates by rotating at a surface speed exceeding the delivery speed of the preceding pair, thereby drawing out the ribbon of flax into a thinner and more uniform strand. Excessive pressure applied by the top weight causes fibre breakage in long line flax, while insufficient force permits uncontrolled slipping and produces irregular sliver density.
Tension limits govern the boundary of the process, beyond which the mechanical drawing action strips natural waxes from the flax stalks and weakens the spun yarn.
Surface Velocity
Speed differentials between consecutive pairs of cylinders determine the degree of extension imparted to the flax sliver during drafting operations. Linear metres per minute measure the feed rate against the delivery rate, establishing the numerical ratio required for fine spinning preparation. Mill floor technicians calculate this mechanical stretch to prevent fibre rupture inside the high humidity atmosphere of the production hall.
Production logs record the rotational speed of each steel cylinder during every shift change to maintain consistent sliver weight across all spinning frames.
Drawing Yield
Finished output weight divided by total raw flax input mass defines the production efficiency achieved through mechanical drawing stages within the mill. Grams per linear metre quantify the resulting sliver density recorded by laboratory balances situated near the output hopper of the drawing frame. Buyer specifications demand strict adherence to these density tolerances before raw flax roving proceeds to wet spinning and subsequent weaving into linen cloth.
Commercial acceptance relies on physical verification of the drawn sliver rather than reliance on processing speeds alone.
