Quantifying Structural Yarn Tension Variance across Multi-Beam Creels in High-Speed Warping
Creel position frictional differential and package diameter decay drive warp tension variance, requiring dynamic compensation to limit loom stoppage rates.
Slasher Wet Draft
Elongation Measure
A ratio of the change in length that occurs when a yarn sheet passes through the aqueous sizing zone of a slasher machine. Calculation of slasher wet draft involves comparing the speed of the squeeze rollers in the size box to the speed of the drying cylinders. This measurement accounts for the stretching of the yarn while it is saturated with liquid.
Mechanical Stretch
Control over the tension is necessary to prevent the permanent loss of yarn elasticity. High slasher wet draft occurs if the drying section pulls the yarn faster than the size box feeds it. Because wet yarns are more plastic than dry yarns, even a small speed differential can lead to elongation which reduces the subsequent weaving performance.
Excessive stretching ruins the yarn.
Moisture Influence
The percentage of draft varies based on the fibre type and the viscosity of the sizing agent. Natural fibres like cotton tend to swell when wet, making them more susceptible to slasher wet draft compared to hydrophobic synthetic yarns. Monitoring the moisture content at the exit of the size box ensures that the yarn has absorbed enough size to protect the fibres without becoming overly stretched.
Process Limit
Excessive elongation during this stage leads to frequent yarn breaks in the loom. The slasher wet draft should typically remain below one point five percent for most weaving applications. If the draft exceeds this limit, the yarn loses its ability to recover from the cyclic stresses of the shedding motion during weaving.
Maintaining low draft levels preserves the weaving efficiency of the warp.