Weight Calculation
Fibre fineness testing relies on precise weight-to-length measurements of highly uniform samples. In professional testing houses, the gravimetric micro-cut represents a classic reference method where thousands of tiny filament sections are sliced to a known length and then weighed. This manual procedure provides an absolute value that does not rely on optical calibration.
Fibre Slicing
Cutting instruments slice the tensioned bundles of fibre using twin parallel razor blades separated by a precise distance. After performing the gravimetric micro-cut, technicians count the individual cut pieces on a microbalance. This step requires manual skill.
Calibration Standard
Moisture correction must be applied to the weighed sample because natural fibres absorb water from the surrounding air. The dry weight obtained after the gravimetric micro-cut is adjusted using standard regain percentages to calculate the true linear density in decitex. This calculation forms the basis for commercial transactions between raw material suppliers and spin mills.
Dyeing Correction
Finishing plants utilize this reference method to calibrate their automated airflow instruments. Airflow testing is faster but must be regularly adjusted against the absolute measurements derived from the gravimetric micro-cut to ensure accuracy. By maintaining this calibration loop, the factory avoids using incorrect yarn sizes that would lead to fabric weight discrepancies in the finished garment batches, protecting the company from financial penalties for failing to meet the tight tolerances specified by major apparel brands.
