Quantitative State
Total weight of a textile specimen when all hygroscopic water is removed by heating. Finding the anhydrous mass requires drying the sample in a ventilated oven at 105 degrees Celsius until a constant weight is reached. This value provides the baseline for all subsequent calculations of moisture content or commercial allowance.
Analytical Sequence
Laboratory technicians use a weighing bottle and a desiccator to prevent the dry sample from absorbing atmospheric humidity before measurement. Because anhydrous mass excludes the weight of water, it represents the actual dry matter of the fiber plus any non-volatile finishes. Small deviations in oven temperature or drying time can lead to inaccurate readings that affect the valuation of large fiber shipments.
Commercial Yield
Financial settlements for raw fiber often rely on the dry weight as a fixed starting point for applying standard regain percentages. Knowing the anhydrous mass allows a buyer to verify that they are paying for polymer rather than water weight accumulated during transit or storage. This calculation protects both parties by removing the variable of ambient humidity from the price.
Boundary Condition
Volatile substances other than water, such as certain spinning oils or low-boiling finishes, can evaporate during the heating process. Consequently, anhydrous mass measurements might slightly underestimate the true solid content if these additives are present in high concentrations. Standard test methods usually specify a pre-extraction of oils to ensure the result reflects only the fiber material.
