Moisture Removal
Dry mass determination requires the removal and exclusion of ambient moisture during the weighing process. The practice of desiccation testing ensures that textile samples do not reabsorb water vapor from the laboratory air before their weights are recorded. This method uses sealed chambers containing drying agents to maintain a low humidity environment.
Equipment Specification
Dry chambers must be airtight and contain effective desiccants such as silica gel or anhydrous calcium chloride. In desiccation testing, these chemicals absorb any residual moisture that enters the chamber when the lid is opened.
Laboratory Procedure
Heated specimens are transferred from the oven to the desiccator and allowed to cool to room temperature. This cooling phase in desiccation testing prevents convection currents from affecting the balance readings. Once cooled, the specimens are weighed immediately to secure the dry mass.
Technicians wear protective gloves to prevent transferring moisture from their hands to the weighing bottle. The bottle remains closed until it is placed on the balance pan.
Testing Accuracy
Moisture regain calculations can be distorted if even a fraction of a percent of water is absorbed during weighing. Consistent desiccation testing is therefore critical when analyzing highly absorbent fibers like wool or viscose. Reliable measurements ensure that blend percentages are calculated correctly.
These calculations prevent financial loss during large-scale yarn procurement.
