Match the source to the package
| Package | Technology to assess | Main checks |
|---|---|---|
| PET bottles | CO₂, often including 9.3 µm; UV for selected applications. | Frosted contrast, wall thickness, recycled content, distortion and bottle control. |
| HDPE or PP bottles and caps | CO₂, fibre or UV depending on resin, pigment and additives. | Contrast, surface change, curved presentation and material variation. |
| Glass bottles and jars | CO₂ or UV depending on speed and finish requirement. | Mark appearance, micro-surface effect, geometry, condensation and handling. |
| Aluminium cans or metal caps | Fibre for bare metal; CO₂ or fibre may remove a compatible coating. | Coating variation, base-metal exposure, curvature and high-speed code quality. |
| Paper labels and cartons | CO₂ for compatible paper, print and coatings. | Reserved mark panel, print contrast, abrasion and barcode verification. |
| Shrink sleeves and film | CO₂, UV or selected fibre after film qualification. | Layer construction, heat effect, perforation risk and registration. |
Why beverage-line speed is not one number
Products per minute alone do not define available marking time. The code length and density, bottle pitch, conveyor speed, number of characters, required code size and product stability all matter. A Data Matrix code may need more scan time than a short date; a rotating bottle can distort either.
The system should be tested using normal and peak conditions. An encoder can follow conveyor-speed changes, while a correctly positioned trigger establishes the start of each mark. Product guides, timing screws or side belts may be needed where bottles are unstable or closely pitched.
Engineer for moisture, washdown and changeovers
Condensation can affect the visible mark, optical path and extraction process. Wet areas also influence the required enclosure, ingress protection, cable routing and operator access. Confirm where the product is dry enough to mark consistently and how the lens will be protected and inspected.
Mixed-format beverage lines need stored recipes and controlled adjustments for focus, marking position and guides. Message selection should reduce the chance of applying the right-quality code to the wrong product. Where coding is a critical control, link message data and downstream vision to the line’s established reject or stop process.
What should be supplied for an application review?
- All package types: bottles, cans, caps, labels, sleeves and cartons from each supplier.
- Exact variable data: dates, batches, line IDs, barcodes, QR or Data Matrix content.
- Production figures: products per minute, conveyor speed, pitch and peak operation.
- Marking position: photographs, drawings and acceptable code window.
- Environment: condensation, washdown, temperature and cleaning routine.
- Quality criteria: permanence, visual finish and machine-readable code checks.
- Integration: controls, recipe data, vision, reject and line-stop requirements.
For PET in particular, see the dedicated CO₂ laser marking for PET bottles guide.