Weft Insertion Monitoring and Short Pick Detection
topic
Air-jet weft insertion monitoring uses optical or capacitive sensors at the receiving selvedge to detect weft tip arrival time, with late arrival below the programmed window indicating insufficient insertion velocity triggering loom stop to prevent the short pick weaving-in that would create a fabric defect, with arrival time data from consecutive picks being used by adaptive control systems to automatically adjust relay nozzle timing and air pressure to maintain consistent insertion velocity as yarn lot characteristics or ambient conditions change.
Role
Prevents the short pick fabric defects that are the most common quality problem in air-jet weaving by detecting insertion failures before the incomplete pick is beaten into the fabric, with real-time insertion monitoring being particularly important at high weaving speeds where the narrow time window between pick insertion and beat-up leaves no opportunity for human observation of incomplete insertions that would otherwise only be discovered in subsequent fabric inspection.