Determining Dry Mass Regain in Flax Roving Processing
Determining dry mass regain in flax roving requires 105°C thermal drying coupled with solvent extraction corrections to separate water loss from spinning oils.
Wet Spun Flax Regain
Commercial Allowance
Standardized moisture levels added to the dry weight of linen yarn produced in a heated water trough define the official mass for trading. The wet spun flax regain represents the accepted percentage of water that a buyer pays for as part of the total weight. Because the spinning process involves complete saturation, the yarn retains a specific amount of moisture even after passing through the drying oven.
This figure is higher than the allowance for dry spun products.
Technical Justification
The internal structure of the flax fibre changes when the pectins soften in the warm spinning bath. Wet spun flax regain accounts for the increased capacity of the cellulosic core to hold water molecules after the yarn is wound onto bobbins. Standard tests in the mill laboratory verify that the material has reached this equilibrium before it is packed into cartons.
Controlled cooling and conditioning rooms ensure that every batch meets the target percentage. Precise monitoring of the ambient air prevents the yarn from becoming too brittle or developing mould during transit. The spinning manager checks these levels every hour to maintain the quality of the fine counts.
Invoice Settlement
Financial transactions for export shipments use the calculated weight based on the laboratory result and the contract percentage. If the wet spun flax regain is found to be lower than the standard twelve percent, the seller might lose revenue. Conversely, a value that is too high results in a penalty for the supplier.
Accuracy in the oven-drying test protects the interests of both the mill and the weaving factory.