Kilos in against Metres out at a Jiangsu Mill Audit
Reconciling raw European flax dry mass against finished fabric metres out exposes certified fiber dilution, protecting buyers from origin fraud in Jiangsu mills.
Boiling off Weight Loss
Mass Evaluation
Measurement of the percentage of mass removed from raw yarn or fabric during the alkaline scouring process determines the efficiency of impurity removal. The boiling off weight loss represents the difference between the dry weight of the linen before treatment and its dry weight after being boiled in a caustic soda solution. Pectins, waxes, lignins and hemicelluloses naturally present in the flax fiber are dissolved during this stage.
Chemical Mechanism
High temperatures and chemical agents break down the non-cellulose components that bind the fiber bundles together. If the boiling off weight loss is too low, the fabric remains stiff and lacks the capacity to absorb dyes evenly. Excessive loss suggests that the cellulose itself is being degraded, which compromises the tensile strength of the finished cloth.
Technicians monitor the liquor ratio and chemical concentration to maintain a consistent result. Precise control of the boiling time prevents the weakening of the molecular chains in the flax.
Quality Specification
Acceptance criteria for bleached linen often specify a maximum allowable percentage for this reduction to ensure structural integrity. A typical boiling off weight loss for high-grade linen yarn ranges between 15 and 25 percent depending on the initial cleanliness of the flax. This value acts as a check for the consistency of the finishing line and informs the final costing of the dyed product.