The Importance of Proper Capping
The capping machine ensures package integrity, product shelf life, and consumer safety. A poorly performing capper causes leakers, under-torqued closures, and production stoppages. On the used market, cappers from manufacturers such as Arol, Zalkin, Nortan, Robino & Galandrino, and integrated monoblock systems from KHS, Krones, and Sidel are commonly available.
Capping Technology Types
| Type | Closure | Application | Key Check |
|---|---|---|---|
| Screw capper | Flat/sport caps | Water, soft drinks | Chuck/spindle wear |
| Press-on capper | Snap-fit caps | Dairy, juice | Pressing force consistency |
| ROPP capper | Aluminium roll-on | Wine, spirits, oil | Threading head condition |
| Crown capper | Crown caps | Beer, cider | Die and punch wear |
| Cork inserter | Natural/synthetic cork | Wine, spirits | Jaw compression, cork feed |
Critical Inspection Points
- Chuck or jaw wear causing inconsistent torque
- Cap sorting and feeding system reliability
- Torque monitoring system calibration
- Star-wheel and container handling precision
- Magnetic clutch condition on screw cappers
Torque Testing
Always perform torque testing during inspection. Application torque should be consistent across all capping heads (±5% variation maximum). Removal torque must meet your product specifications. Use a calibrated torque meter and test at least 50 containers across all heads.
Common Issues
Capper Problems to Watch
- Worn chucks causing cross-threading — replacement sets cost €2,000–€8,000
- Inconsistent pick-up from cap sorter — causes line stoppages
- Missing or bypassed torque monitoring — creates quality control risks
- Magnetic clutch deterioration — causes gradual torque drift
- Cap chute design incompatible with your specific closure — verify before purchase
Frequently asked questions
How do I know which capper type I need?
The closure type determines the capper required. Screw cappers for threaded closures, ROPP for aluminium roll-on caps, press-on for snap-fit closures. Your packaging supplier can confirm the exact closure specification.
Can a screw capper handle different cap sizes?
Yes, with appropriate change parts (chucks, sorting bowls, guides). Verify the machine range covers your required cap diameters.
How often should capping chucks be replaced?
Typically every 2–5 million cycles depending on material and closure type. Inspect for wear patterns and torque drift during regular maintenance.