Mass Determination
Precision weighing techniques measure minuscule changes in specimen mass to determine chemical residue or moisture content after solvent extraction. Microbalance gravimetry is used in mill laboratories to measure the weight of wax and pectin residues extracted from small linen samples with high accuracy. This analytical technique provides a reliable way to assess the efficiency of chemical scouring and bleaching treatments.
Analytical Method
Dried samples are placed on the suspended pan of a microbalance inside a draft-free enclosure to prevent air currents from disrupting the measurement. The balance measures the sample weight to the nearest microgram before and after the extraction process to calculate the exact percentage of non-cellulosic components removed. This quantitative measurement is used to adjust the concentration of sodium hydroxide in the scouring bath, which optimizes chemical consumption and reduces processing costs.
This precision is necessary because small changes in wax content have large effects on the fiber’s dye absorption.
Environmental Influence
Laboratory temperature and humidity must be kept constant to prevent moisture from altering the sample weight during weighing. Specimen containers are kept in desiccators until the moment of weighing to ensure that the fibers remain dry. This precaution is necessary to ensure the repeatability of the test results.
