Auditing Chinese Spinning Shed Moisture Regain and Processing Mass Shortfalls
Linen yarn buyers eliminate moisture invoice inflation by calculating landed payments on laboratory oven-dry mass plus official 12 percent regain.
GB/T 9994
Moisture Standard
National textile standards in China establish conventional moisture regain values for major textile materials to regulate trade and weight calculations. This regulatory document, designated GB/T 9994, defines the official regain percentages that must be applied when calculating the commercial weight of fibers and yarns. It ensures a uniform baseline for commercial transactions across the domestic supply chain.
By setting these specific limits, the standard prevents commercial disputes arising from moisture variation during transport.
Testing Protocol
The document prescribes the drying and weighing methods used to determine the moisture regain of fiber samples under laboratory conditions. Technicians must dry the textile specimen in a ventilated oven at one hundred and five degrees Celsius until it reaches a constant mass. The difference between the original mass and the oven-dry mass is then calculated as a percentage of the dry mass.
This protocol is applied by customs laboratories and mill quality control departments to verify compliance during yarn shipment handovers. The standard stipulates distinct regain values for raw flax, spun linen yarn and blended fabrics to account for the different moisture capacities of these materials, ensuring that each fiber type is assessed under its appropriate physical parameters.
Market Application
Commercial contracts for yarn deliveries within the Chinese market must reference these official regain figures to determine final payments. When moisture testing shows that a batch of yarn exceeds the stipulated regain limit, the transaction price is adjusted using the standardized formula. This requirement stabilizes the linen trade by ensuring that material yields are calculated fairly for both the spinner and the fabric producer.
Compliance with this standard is a prerequisite for mill certification.