Accounting for Wet Finishing Mass Additions in Commercial Mill Procurement
Accounting for wet finishing mass additions separates greige fiber weight from chemical solids to prevent yield overbilling and structural fabric downgrades.
Dry Add-on Calculation
Measurement Method
Quantitative assessments determine the amount of solid chemical residue fixed to a fabric surface after the moisture has been evaporated. Dry add-on calculation compares the weight of the untreated fabric to the weight of the fabric after it has been padded and cured.
Industrial Logic
Manufacturers use this figure to verify that the application of flame retardants or water repellents meets the technical specification. A dry add-on calculation provides a more accurate measure of chemical efficiency than wet pickup alone because it accounts for the concentration of the chemical bath.
Chemical Yield
Solid content levels influence the physical properties and the cost of the finished textile. During the dry add-on calculation, the laboratory must ensure that the fabric has reached a state of equilibrium with the ambient humidity to avoid errors caused by residual moisture. This process involves weighing a sample, applying the chemical, drying the sample and weighing it again to find the mass of the solids.
Natural Fluctuations
Fibre density or weave structure cause small differences in chemical retention across a production lot. While the dry add-on calculation provides a target, commercial contracts usually permit a small percentage of variance to account for these natural differences in fabric behavior.