Real Time Size Add on Sensing and Adaptive Squeeze Control in High Speed Bast Warp Sizing
Real time microwave sensing and adaptive squeeze roll pressure tuning stabilize bast warp size add-on to maximize loom efficiency and cut yarn breaks.
Non Newtonian Fluid Shear Thinning
Rheological Behavior
Deformation behaviour in complex liquids is characterized by a decrease in viscosity when the rate of mechanical agitation increases. The phenomenon of non Newtonian fluid shear thinning is highly relevant to the application of starch sizing on flax warp yarns. This flow property ensures the liquid remains stable during pumping but becomes highly fluid when applied under high mechanical pressure.
It allows the protective sizing to spread evenly over the yarn surface.
Fluid Dynamics
High shear forces inside the sizing box temporarily break the weak intermolecular bonds of the polymer starch chains. As these long molecules align parallel to the flow direction, the internal friction of the fluid drops significantly. This molecular alignment allows the sizing to penetrate into the yarn interstices before the liquid exits the pressure rolls.
Once the shearing action stops, the fluid returns to its highly viscous state, locking the coating onto the outer sheath of the yarn to prevent fuzz formation. This reversible transition ensures that the yarn receives a uniform coating that remains intact during subsequent spooling and weaving operations.
Process Outcome
Continuous monitoring of the viscosity index in the storage tank is recorded on the batch production log sheet. The mill team uses this data to maintain the correct solids concentration of the sizing paste. Inadequate control of the rheological properties leads to either excessive yarn stiffness or insufficient protection during weaving.
Consistent management of non Newtonian fluid shear thinning prevents yarn shedding and breakages in high-speed looms.