ASTM D1909

Regain Specification

Technical staff at the spinning stage utilize these specific regain constants to adjust the raw mass of flax and other natural fibres before chemical processing or yarn formation. Each fibre type possesses a distinct affinity for water, a physical characteristic that influences the final weight of a production batch. The standard provides a list of regain values expressed as a percentage of the oven dry mass of the material.

Spinning mills adopt these constants to verify that yarn yields match the quantity of raw fibre purchased from the source. Accounting departments apply these factors to determine the legal invoiced weight of textile goods. Accurate application of these constants ensures that moisture content does not artificially inflate the cost of goods sold.

Operational Variance

Variations between the commercial regain values mandated by the standard and the actual measured moisture in a fibre lot indicate the necessary mass adjustment for transaction integrity. Laboratories calculate the adjustment by subtracting the established standard regain from the measured moisture content of the specific sample. A positive result denotes that the fibre currently holds excess water above the commercial norm, requiring a downward correction of the total mass.

Mills implement this process to ensure that payment matches the actual dry fibre content contained within each bale. This practice stabilizes the valuation of natural fibres through the entire supply chain.