PET Preform Mould Maintenance and Refurbishment: Maximising Mould Life and Production Uptime
A PET preform mould is one of the most significant capital investments in a bottling operation. A systematic maintenance programme and timely refurbishment can double its productive life — and prevent the unexpected downtime that costs far more than the maintenance itself.
Planned Preventive Maintenance Schedule
| Interval | Tasks | Objective |
|---|---|---|
| Daily | Visual inspection of gate area; check cooling water flow rates and temperatures; inspect preform quality (weight, clarity, gate quality) | Early defect detection |
| Weekly | Check hot runner temperature stability across all zones; inspect ejector pins; verify cycle time stability | Process drift detection |
| Per 500K shots | Inspect gate inserts and nozzle tips; check valve pin condition (if valve gate); check core pin surface for scoring | Wear part inspection |
| Per 1M shots | Full disassembly of hot runner; clean all manifold channels; replace O-rings and seals; re-polish cavity surfaces; descale all cooling circuits | Preventive overhaul |
| Per 2–3M shots | Dimensional inspection of cores, cavities, and neck finish tooling; replace worn gate inserts; check manifold heater elements; re-certify mould to specification | Life extension overhaul |
Wear Indicators — When to Act
| Symptom | Root Cause | Action Required |
|---|---|---|
| Gate scar quality deteriorating (strings, vestige) | Nozzle tip wear; valve pin tip damage | Replace gate insert or valve pin tip |
| Preform weight variation increasing (cavity to cavity) | Manifold channel imbalance; blocked or worn nozzle orifice | Hot runner service; nozzle tip inspection |
| Cycle time increasing over weeks/months | Cooling circuit scale build-up | Chemical descaling of all cooling circuits |
| Surface haze or crystallisation spots on preform body | Hot spot in cooling circuit — partial blockage | Cooling circuit inspection and flush |
| Preform dimensional drift | Core or cavity surface wear; neck tooling wear | Dimensional inspection; grinding and re-plating if applicable |
| Increasing flash at parting line | Parting face wear; mould clamping issue | Parting face grinding; check machine clamp force |
Hexamech Mould Refurbishment Service
Hexamech offers mould refurbishment services for preform moulds — including those not originally manufactured by Hexamech. Our refurbishment scope can include:
- Hot runner manifold strip-down, cleaning, and reassembly
- Gate insert and nozzle tip replacement
- Core pin and cavity re-polishing to original surface specification
- Cooling circuit chemical cleaning and flow verification
- Dimensional inspection and report against original specification
- Conversion kits for format changes or neck finish updates
- Full mould qualification after refurbishment — T1 trial and sign-off
Need to adapt an existing mould to a new preform format, different neck finish, or changed resin? Hexamech conversion kits provide a flexible and cost-effective way to extend mould utility without the capital cost of a new tool. Fast changeovers, validated performance — designed and manufactured in Ahmedabad.
Mould Refurbishment, Spare Parts & Conversion Kits
Hexamech supports customers beyond mould delivery — with refurbishment services, spare parts supply, and conversion kits that extend mould life and production flexibility.
Enquire About Mould Services