Mass Measurement
Solids content remaining on a textile substrate after finishing and drying quantifies the amount of chemical agent applied. The dry add on weight excludes the weight of the water or solvent used as the carrier during padding or coating. The measurement represents the actual amount of resin or functional softener fixed to the fibres.
Calculations compare the weight of the treated fabric to its original weight at the same moisture level.
Calculation Method
Subtracting the initial fabric weight from the final dry weight provides the total mass of the added chemicals. The dry add on weight is often expressed as a percentage of the original substrate mass. If a 300 gram sample weighs 315 grams after finishing and bone drying, the value is five percent.
This figure verifies that the chemical concentration in the bath matches the physical deposit on the cloth.
Process Control
Variations in the pickup of the wet solution or the concentration of the mix alter the final result. Monitoring the dry add on weight allows production managers to adjust the squeeze rollers or the speed of the line. Insufficient loading might lead to a failure in functional performance such as water repellency.
Overloading wastes expensive chemicals and may degrade the physical strength of the fabric.
Standard Compliance
Testing for specific finishes requires the deposit to fall within a narrow window. The dry add on weight serves to confirm that the factory met the specification defined in the technical data sheet.
