Determining Fibre Commercial Mass under International Regain Standards
Determine commercial mass by calculating clean oven-dry mass from certified core samples and adding standard international commercial regain allowances to settle invoices.
Dynamic Thermodynamic Equilibrium
Moisture Balance
State of simultaneous moisture absorption and desorption between a textile material and its surrounding atmosphere represents the stable point of conditioning. In laboratory tests, dynamic thermodynamic equilibrium occurs when the rate of water molecules entering the fibre equals the rate of those leaving it. This state depends on both relative humidity and ambient temperature.
Chamber Conditioning
Standard testing chambers maintain a controlled environment of twenty degrees Celsius and sixty-five percent relative humidity to achieve this balance. When a textile lot reaches dynamic thermodynamic equilibrium, its physical properties become stable. This stability is required before any official strength, weight, or count test is conducted.
Vapour Transfer
Fibres continuously exchange water molecules with the air through active diffusion. In this process, the water vapor pressure at the fibre surface aligns with the partial pressure of water vapor in the surrounding environment. To confirm this state is reached, the sample is weighed at progressive intervals of two hours.
If the change in mass between consecutive weighings is less than zero point one percent, the system is deemed to have reached its steady state. This ensures that subsequent physical measurements are both reproducible and accurate across different testing laboratories.
Processing Consistency
Production yield depends on this stable moisture state because dry or over-moist fibres behave differently under mechanical strain. Reaching the balance ensures that fabric behaves predictably during cutting and sewing. Variations in this state lead to dimensional changes in finished garments.