Angular Variance
Measurement of the spatial discrepancy between the theoretical and actual yarn path at the receiving side of a loom provides a metric for insertion stability. A high arrival angle deviation indicates that the filling yarn is not arriving in a straight, predictable line, often caused by inconsistent air pressure or mechanical wear in the rapier head. This parameter determines the reliability of the selvedge formation and the overall efficiency of the weaving machine.
Insertion Impact
Airflow fluctuations or yarn hairiness can disrupt the flight path of the thread across the shed. When arrival angle deviation increases, the yarn may miss the catchment zone of the receiving gripper or suction tube. This failure leads to machine stoppages known as filling stops.
Regular monitoring of this deviation allows technicians to adjust the timing of the main and relay nozzles.
Fabric Quality
Misalignment at the point of arrival creates loops or kinks near the fabric edge. If arrival angle deviation remains uncorrected, the resulting cloth exhibits uneven selvedges and potential structural weaknesses in the outermost warp ends. These defects are particularly problematic in high density technical fabrics where edge uniformity is a primary requirement for subsequent coating or lamination.
Control Logic
Optical sensors or contact probes at the far end of the reed measure the precise moment and angle of yarn arrival. Advanced loom controllers use these data points to modify the solenoid valve firing sequence in real time. Consistent arrival ensures that every pick is laid at uniform tension across the entire width of the machine.
