Moisture Regain Corrections in Gravimetric Linear Density Testing of Hackled Line Flax
Accurate gravimetric testing of line flax linear density demands dry mass weighing and standard twelve percent regain adjustment per ISO 6741.
Test Specimen Conditioning
Moisture Equilibrium
Allowing fiber samples to reach a stable moisture level in a controlled environment is the necessary first step for all physical testing. Executing test specimen conditioning ensures that the flax fibers have the same moisture content before their strength or linear density is measured. This process removes the influence of previous storage conditions on the test results.
Standard Procedure
Conducting this process requires placing the flax samples in a laboratory where the temperature is held at twenty degrees Celsius and the relative humidity is kept at sixty-five percent. The test specimen conditioning must continue for at least twenty-four hours to allow the moisture to distribute evenly throughout the fiber bundle. This holding time is critical because flax is a dense fiber that absorbs moisture slowly from the surrounding air.
When the sample weight stabilizes, the material is ready for tensile testing or micronaire analysis.
Testing Accuracy
Eliminating moisture variations between samples is necessary to obtain reproducible results that can be compared across different laboratories. Without proper test specimen conditioning, the measured fiber strength can vary by up to twenty percent, leading to incorrect grading and potential disputes with buyers. This preparation guarantees the fairness of the quality certificates.