Determining Dry Mass Regain in Flax Roving Processing
Determining dry mass regain in flax roving requires 105°C thermal drying coupled with solvent extraction corrections to separate water loss from spinning oils.
Roving Bobbin Sampling
Verification Protocol
Quality control inspections performed on the intermediate stage of the spinning process verify the uniformity of the fibre bundle before it reaches the fine spinning frame. During roving bobbin sampling, the lab technician selects several units from different rows of the roving machine to check the weight per unit length. This step identifies variations in the drafting process that would otherwise lead to thin or thick spots in the final yarn.
Random Selection
The measurement involves winding a specific length of the roving onto a reel and weighing it on an electronic scale. If the results from roving bobbin sampling deviate from the target grain or tex, the mechanic must adjust the gears on the drafting rollers. Consistent results here ensure that the twist is distributed evenly across the entire lot.
Random selection of the bobbins prevents the operators from presenting only the best work for inspection. Detailed records of these tests allow the mill to trace the performance of individual machines over several shifts.
Draft Accuracy
Problems found at this stage are much cheaper to fix than those discovered in the finished yarn. A failed sample usually leads to the immediate inspection of the preceding drawing frames.