Textile Machinery, Maintenance and Automation
Textile Machinery, Maintenance and Automation examines machine systems, drives, sensors, control and maintenance strategy. The exam tests machine function, preventive maintenance, condition monitoring, automation and OEE calculations.
Core concepts
- Major machines include blowroom, cards, draw frames, combers, speed frames, ring and rotor frames, looms, knitting machines, and dyeing and finishing ranges.
- Preventive maintenance schedules lubrication, belt tension, roller alignment, calibration and replacement of wear parts.
- Condition monitoring uses vibration, temperature, current and oil analysis to detect incipient faults.
- Automation uses sensors, PLCs, servo drives, vision and data acquisition; calibration and fail-safe design are essential.
- OEE = availability × performance × quality.
Worked example
A loom is scheduled 480 min; downtime is 48 min; ideal cycle is 0.5 min/unit; output is 720 units; good units are 684. Availability = 432/480 = 90%. Performance = (720 × 0.5)/432 = 360/432 = 83.3%. Quality = 684/720 = 95%. OEE = 0.90 × 0.833 × 0.95 = 71.3%. The largest loss here is speed or performance, not quality.
Traps
- Including planned maintenance in downtime without defining OEE scope.
- Confusing machine utilization with OEE.
- Ignoring calibration drift in automated inspection.
- Replacing parts without root-cause analysis.