Thermogravimetric Analysis of Non-Cellulosic Degradation Kinetics in Bast Fibres
Non-cellulosic thermogravimetric kinetic analysis quantifies binder levels to prevent hackling yield losses and wet-spinning breakage.
Bundle Cohesion
Fibre Uniformity
Parallel filament alignment characterizes bundle cohesion during the carding stage in Chinese flax mills, where mechanical friction holds the parallel strands together before drafting. The technical specification appears in the spinning mill quality ledger as a direct measurement of draft resistance across a standard span. Shear force applied on the roving frame pulls the aligned plant cells apart at a measurable threshold.
Short staple segments reduce the contact area between adjacent strands, dropping the measured tension limit below the mill acceptance threshold.
Draft Resistance
Machine operators verify draft resistance on the roving frame before passing the material to the wet spinning lines. Twist insertion depends entirely on the friction generated between neighbouring filaments as the drawing rollers accelerate. Insufficient lateral pressure causes premature separation of the strand, leading to thick spots in the yarn and subsequent breakage on the ring frame.
High friction values prevent smooth drawing action, forcing the supervisory team to adjust the pin density on the gill box.
Export Specification
Buyer acceptance criteria require specific bundle cohesion limits for linen yarns destined for international weaving houses, differing significantly from the internal mill standards used for domestic grey goods. Mill laboratories record these values on the commercial test certificate accompanying each export lot. Low friction ratings trigger immediate rejection by the merchant inspector, who bases the final purchase decision on breaking length trials rather than visual appearance alone.
Final yarn strength depends on maintaining these frictional limits through every stage of preparation and spinning.