Temperature Limit
Chemical breakdown of cellulose molecules under the influence of elevated temperatures alters the physical properties of flax fibres during industrial drying and finishing processes. This phenomenon, known as thermal stress degradation, is monitored closely at the fabric finishing stage where wet woven linen is subjected to high-temperature stenter drying. Chemists record the temperature exposure limits in the finishing department’s process log to prevent loss of fabric strength.
Structural Damage
Excessive heat causes the polymer chains within the flax cell wall to depolymerise, which reduces both fibre elasticity and tensile strength. When thermal stress degradation occurs, the linen fabric becomes brittle and loses its natural luster, making it unsuitable for high-end garments. In addition, the damaged cellulose exhibits uneven dye absorption, resulting in visible color variations across the finished fabric surface.
Quality Check
Finishing mills measure the residual tear strength of the fabric after drying to ensure that the heat settings have not compromised the structural integrity of the linen. The laboratory compares these post-finishing test results against the buyer’s acceptance criteria to verify that the fabric meets international standards for wear resistance. This evaluation is recorded on the final product quality release form, which is signed off before the linen is packed for export.
By maintaining strict control over the stenter drying temperatures, the mill avoids the costly rejection of entire production batches due to heat damage.
