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.
Viscoelastic Roll Deformation
Physical Phenomenon
Time-dependent structural change in rubber-covered cylinders occurs when they are subjected to continuous rotational and compressive stresses. This phenomenon is known as viscoelastic roll deformation, and it significantly affects the squeezing action in textile mills. The continuous alteration of the roll shape modifies the width of the pressure zone where the yarn sheet is squeezed.
It is a critical factor in determining the uniformity of sizing application.
Mechanical Behavior
When the rotating roller presses against its metal counterpart, the rubber layer experiences both elastic compression and viscous flow. Because the rubber cannot recover its original shape instantaneously, the point of maximum compression shifts slightly in the direction of rotation. This asymmetry causes heat generation and alters the pressure profile across the contact zone of the yarn sheet.
The temperature of the rubber rises, which further lowers its resistance to deformation and changes the viscosity of the passing adhesive. To prevent these changes from compromising the yarn quality, mills must use rollers with specialized elastomeric compounds designed to withstand the cyclic stress of high-speed textile processing without excessive heat buildup.
Quality Impact
The mill technician measures the roll profile and monitors the surface temperature during regular maintenance inspections. The diagnostic report is recorded in the equipment logbook to plan the regrinding schedules for the roll covers. If the rubber cover is allowed to distort beyond the allowable limits, it produces uneven sizing along the yarn sheet.
Continuous monitoring of viscoelastic roll deformation prevents yarn defects and ensures stable weaving performance on high-speed looms.