Determining Dry Cellulosic Mass Yield in Wet Flax Roving Processing
Dry cellulosic yield in wet flax roving requires gravimetric tare subtraction, moisture regain adjustments, and chemical boil-off loss corrections per lot.
Centrifugal Hydroextraction
Mechanical Dehydration
Rotational force removes excess liquid from wet yarn packages or loose flax fibres after scouring and dyeing. Efficient centrifugal hydroextraction reduces the energy required for the subsequent thermal drying stage by lowering the initial moisture content. The material is placed in a perforated drum that spins at high speeds to force the water outward.
This process stops when the moisture regain reaches a level that prevents dripping.
Kinetic Dewatering
The force generated by the centrifuge pushes the water through the interstices of the yarn and out of the drum. Unlike thermal drying, centrifugal hydroextraction does not involve heat, which protects the natural lustre and strength of the flax. The duration of the cycle and the rotational speed are calibrated based on the density of the yarn and the weight of the load.
If the centrifuge is unbalanced, the resulting vibration can damage the machine and lead to uneven moisture removal across the batch. Operators must distribute the bobbins or loose fibre evenly to ensure a smooth operation. Most mills target a residual moisture content of forty to fifty percent before the yarn moves to the ovens.
Thermal Savings
Every litre of water removed by the centrifuge is a litre that does not need to be evaporated by steam or electricity. This step significantly lowers the operational cost of the finishing department. It represents a boundary between wet processing and final packaging.