Evaluating Technical Flax Fiber Bundle Widths Using Optical Microscopy
Optical microscopy of resin-embedded cross sections determines true technical flax bundle widths, separating spinnable fine line from coarse drafting defects.
Tow
Short Fibre
Flax extraction separates raw crop material into long line fibres and a secondary output known as tow. This material consists of tangled, shorter stalks that drop away during the scutching process. Mechanical carding aligns these pieces to prepare them for drafting into a lower count yarn.
The standard defines this category by its shorter staple length compared to the primary line fibre extracted from the same crop. Because it lacks the high tensile strength of long flax, factories assign it to coarser textile applications.
Production Methodology
Scutching machines beat the dried flax stems to break the woody core while mechanical brushes pull the long strands free. Remaining material falls into collection bins located beneath the processing line. Operators then gather these remnants for cleaning to remove residual bits of shive or vegetative matter.
Refinement occurs through multiple passes of a carding engine where steel pins straighten the disordered tufts. Spinning mills process the cleaned output into different grades based on the remaining impurities and average staple length.
Market Classification
Export documentation distinguishes these grades from primary flax line to prevent confusion during customs valuation. Buyers examine the cleanliness and moisture content specified in the sales contract when assessing a delivery of tow. Spinning machines require specific staple lengths to maintain consistent tension during yarn formation.
Variations in the ratio of these fibres within a mix directly alter the mechanical properties of the finished linen thread. Mills price this input lower than line fibre because the processing waste reduces overall manufacturing efficiency.