Troubleshoot from evidence, not repeated random adjustment
Record the product batch and condition, film and artwork revision, machine recipe, lane, time, alarm history, recent maintenance and the exact defect. Retain affected and acceptable packs. A fault that looks similar can have different causes, and changing several settings at once destroys useful evidence.
Start by checking whether the problem is product, film, dosing, sealing, cutting, coding, downstream handling or an interface between them. Return only authorised settings to their approved baseline and follow the machine manual and safe isolation procedures.
Dose variation or missing product
Check product supply, hopper or tank level, refill disturbance, air in the feed, temperature, density, viscosity, aeration, bridging, pump priming, auger condition and the ready/dose-complete signal sequence. On multi-lane machines, compare lanes rather than relying on a combined average.
Confirm the measurement method and tare. A volumetric dosing movement can be repeatable while mass changes because product density has changed. A weighing result can still be affected by vibration, product in flight or unstable settling.
Weak, open or contaminated seals
Retain the exact film reel and record its structure, thickness and storage condition. Inspect sealing surfaces for contamination, damage or misalignment and check approved temperature, pressure and dwell settings. Product in the seal can come from overfill, dust, drips, strings, poor settling or mistimed dosing.
Do not compensate indefinitely by increasing temperature. Excess heat can distort film or reduce operating margin. Use the film supplier’s data and a controlled seal trial, then verify integrity with the agreed method.
Print drift, incorrect cut or unstable sachet length
Check mark quality and contrast, sensor position, web tracking, tension, reel winding, print repeat and approved recipe. Inspect the film path and rollers for contamination or damage. Record whether the fault appears after a reel change, splice, speed change or stop/restart.
A registration system controls the relationship between the mark and machine cycle; it cannot correct inconsistent print repeats beyond its designed range. Compare the affected reel with the approved artwork and film data.
Missing, blurred or misplaced code
Check coder-ready status, consumables, substrate compatibility, print head condition, trigger/encoder signals, code data and the physical code area. Determine whether the code is absent, incorrect, unreadable or simply outside its intended location.
Challenge the agreed fault response. A coder alarm may need to stop the machine, prevent release or trigger a verified reject depending on the line design and quality procedure.
Film tracking, wrinkling or poor forming
Check reel alignment, web threading, guide and roller condition, forming-part cleanliness, tension and film consistency. Confirm that the web width, thickness, winding and core match the approved specification. Wrinkles can propagate into longitudinal or transverse seals.
Do not use excessive guide force to hide an upstream alignment or material problem. Mark the point at which the web first deviates and work backwards through the path.
Poor cutting, perforation or strip separation
Inspect cutter or perforation condition, alignment, approved settings and the relationship to registration. Check whether product, seal thickness or web tension changes the load. On multi-lane webs, identify whether the defect follows one lane, one slit line or the whole width.
Handle blades and cutting assemblies only under the approved safe method. Replace or service components according to the machine documentation rather than improvising adjustments.
Fault-isolation table
| Dose outside acceptance | Product condition and feed; level/refill; filler priming or screw condition; recipe; timing; lane; measurement method. |
|---|---|
| Product in seal | Overfill; nozzle cut-off; dust or stringing; drop/settling time; sachet volume; dosing-to-jaw sequence; product feed pressure. |
| Weak or leaking seal | Film structure/condition; contaminated or damaged jaws; approved temperature, pressure and dwell; cooling; pack handling. |
| Print/cut drift | Eye mark; sensor; print repeat; web tension/tracking; reel/splice event; speed or restart; recipe. |
| Missing or wrong code | Coder status; data; trigger/encoder; consumables; substrate; code area; access control; fault response. |
| Intermittent empty pack | Product-low logic; ready/dose-complete handshake; hopper bridging or tank interruption; fault/restart sequence. |
| One weak lane | Lane-specific filler, nozzle or auger; web/seal alignment; code/cut path; sample identity; disabled-lane logic. |
| Downstream jam | Discharge orientation; static; strip/single-pack setting; conveyor capacity; counting/collation; stop and restart signals. |
Know when to stop and escalate
Stop production when a defect affects safety, guarding, electrical condition, uncontrolled product hazard, critical pack integrity or any quality rule requiring hold. Do not bypass interlocks, defeat guards or continue with an unexplained recurrent fault.
Provide support with machine identification, alarm text, recipe, product and film data, photos or video, retained samples, timeline and changes already made. Good evidence shortens diagnosis and prevents repeated unsafe intervention.
Safety reference: HSE guidance on maintenance of work equipment. Troubleshooting and maintenance must follow the supplied machine instructions, safe isolation and a competent site-specific assessment.