Flax Fibre Non Cellulosic Content Impact on Hackling Yield
Non-cellulosic content above 3.5% lowers hackling line yield, increasing tow waste and landed line fibre cost per finished metre.
Lignin
Organic Binder
Complex phenolic polymers found within the cell walls of woody plants provide the compression strength and rigidity necessary for upright growth. Within the flax plant, lignin acts as the waterproofing agent that helps protect the internal structure from microbial decay. Excess amounts of this substance within the harvested flax make the resulting fibre coarse and difficult to separate into fine strands.
The concentration of this compound remains low in the highest grades of linen fibre targeted for apparel use.
Removal Stage
Mechanical and chemical actions during the scutching and hackling stages aim to remove as much woody material as possible. While residual lignin provides some essential structural stability to the stem, too much inhibits the penetration of dyes and finishing chemicals into the fibre. Mills use specific oxidative treatments to reduce the content of these brownish molecules without weakening the overall fibre integrity.
Effective control at this level prevents the development of stiff patches in the final woven cloth.
Fibre Evaluation
Measurement of the non cellulose fractions often targets this polymer to determine the purity of a sample. Laboratory results showing higher than average lignin percentages usually correlate with brittle straw or under retted crops. Managing the levels of this resinous binder ensures that the spinning process runs smoothly without build up on the machine rollers.
The balance between flexibility and strength defines the success of the flax refining process.