This machine tutorial explains how to operate and troubleshoot fat for bag making lines: operator-centric checklist that prevents surprises on factory acceptance, commissioning, and operator standard work. It is written for shift supervisors, maintenance technicians, and application engineers who need repeatable procedures—not theory alone.
Machine scope and operating context
Yaoshg field teams use this discipline on presses and converting lines built in Wenzhou—from early stack flexo units through CI, gravure, laminating, slitting, bag making, and paper container equipment. The steps below assume normal safety lockout rules, OEM manual limits, and documented substrate specifications for each job.
Many FAT sessions overemphasize maximum speed and under-test daily operating realities. An operator-centric FAT should include startup repeatability, changeover effort, and fault recovery behavior.
Prepare a structured FAT checklist before travel with clearly defined pass criteria. Ambiguous statements like runs smoothly should be replaced with measurable values such as reject rate, length tolerance, and restart time.
Step-by-step machine procedure
Require demonstrations at low, nominal, and high speed because instability can appear only in one band. Speed-window testing also verifies control loop robustness beyond showcase settings.
Factory acceptance on export orders follows dry-run mechanical verification, wet run at agreed speed, and SAT criteria signed with register photos. Operators should participate in FAT—not only engineering managers—because night crew runs the line after install.
Centerlining captures the settings that produced first good output. Without centerline data, every shift restart becomes informal trial and error.
Operator shift checklist
- Complete dry-run mechanical checks before wet stock.
- Capture FAT photos, torque sheets, and sign-off criteria.
- Centerline critical settings after first stable production run.
- Train backup operator on emergency stop and restart sequence.
Common defects and corrective adjustments
Operator interface quality matters as much as mechanical output. Alarm text clarity, guided recovery steps, and parameter access levels should be evaluated while real faults are intentionally introduced.
End FAT with a documented punch list and owner assignment for each open item. Clear closure tracking reduces commissioning delay and avoids scope disputes after shipment.
SAT disputes usually trace to undefined substrate, ambiguous speed target, or missing utility spec—not hidden machine defects. Resolve assumptions in writing before witness tests.
Maintenance records and when to call service
Store FAT checklists, torque sheets, and training sign-offs with serial number. Update centerline after major maintenance or substrate platform changes.
If mechanical adjustment, drive parameter changes, or repeated defects exceed on-site scope, log serial number, job recipe, and photos before contacting Yaoshg service. Commissioning engineers can remote-review HMI trends when VPN or data export is available—faster resolution when shift records are complete.