Calculating Raw Linen Greige Off-Loom Mass Loss
Off loom mass loss in linen greige averages 14 to 22 percent, requiring correction for sizing pickup, moisture regain, and non cellulosic scour extraction.
Boil off Mass Reduction
Quality Benchmark
Laboratory testing of yarn or fabric samples to determine the weight lost during a standardized boiling water treatment identifies the presence of soluble impurities. The result is recorded as the boil off mass reduction. Manufacturers use this figure to assess the cleanliness of linen after it leaves the spinning frame or the loom.
It accounts for the removal of sizing agents and natural oils that would otherwise interfere with uniform finishing.
Laboratory Procedure
Verification starts with weighing a conditioned sample before it enters a neutral or slightly alkaline boiling bath for a fixed duration. Once the treatment ends, the sample is rinsed, dried to a constant weight and re-weighed under identical atmospheric conditions. Calculating the difference reveals the boil off mass reduction as a percentage of the original dry mass.
This process ensures that the material is prepared for consistent penetration of liquid ammonia or other specialized linen treatments.
Finishing Implication
Samples from different flax crops show varying levels of weight loss due to differences in the retting process. Poorly retted fibres contain more pectins and therefore show a higher reduction during the boil. Mills set narrow tolerances for this value to maintain batch-to-batch consistency in the final cloth weight.