Solubility Correction
A standardized mathematical coefficient corrects for the minor loss of insoluble fibre during chemical dissolution testing of multi-component textile blends. Within quantitative fibre analysis, the empirical d-factor represents the mass correction factor applied to the remaining dry residue to calculate its original pre-extraction weight. This correction compensates for the action of aggressive solvents that may slightly attack the non-target fibre.
Quantitative Calculation
Applying this factor prevents systematic errors that would otherwise distort the calculated composition of the blend. When calculating the percentage of viscose in a wool-viscose blend, the empirical d-factor adjusted residue mass is used in the final equation. This formula ensures that the reported fiber percentages align with the actual content, allowing the mill to generate legally compliant care labels.
Without this step, the slight dissolution of the wool would lead to an incorrect overestimation of the viscose percentage in the fabric.
Analytical Variation
Specific factors are defined for each fibre-solvent combination in official testing standards such as ISO 1833. For example, a factor of 1.00 is used for nylon in cold formic acid, whereas polyester in boiling dimethylformamide requires a slightly higher factor due to minor mass loss.
Testing Protocol
Standardized calibration runs are periodically executed using pure fibers to verify the accuracy of these correction factors under local laboratory conditions. This quality check is essential because variations in solvent purity or heating equipment can alter the solubility of the reference fiber.
