Bottled water production: solve one problem
Water Bottle Date Code Problems: Find Where the Code First Fails
A code missing at packing may never have been applied, may have moved outside the inspection view, or may have deteriorated after marking. Buying a different coder before identifying that checkpoint can leave the original problem unresolved.
Segregate suspect product under the quality procedure. Check both the approved date/lot data and readability on identified bottles immediately after marking and after downstream contact. Keep inkjet, direct PET laser and label marking as separate application routes.

Compare the same bottle at defined checkpoints
Record the bottle or label material revision, actual marking location, coder model, approved job and line phase. Photograph identified samples using the same lighting, orientation and agreed reading distance. Keep product temperature, visible moisture and the interval before each observation with the sample record.
Check correctness separately from appearance: a sharp code can still contain the wrong lot, date or template. Ask the quality owner to define required content, readability, durability challenge and product disposition. Do not substitute a printer's 'print complete' signal for a bottle-level check.
Illustration, not a production result: 9 unreadable codes in 500 bottles is 1.8%; 4 in a separate 500-bottle window is 0.8%. Keep windows, conditions and inspection method explicit. A lower sample percentage neither proves the cause nor authorizes release of earlier suspect stock.
Distinguish four failure patterns
Keep matched samples from startup, steady running and restart. Use safe external observations; do not reach into a moving line to retrieve a bottle. A final packing sample alone cannot locate the first failure.
| Pattern | Evidence | Review boundary |
|---|---|---|
| No mark immediately after coding | Sample identity, approved job, product-detect and permitted status records | Trigger/data/marking execution, not assumed abrasion |
| Readable at first, damaged after contact | Linked before/after images, first contact location and elapsed time | Handling and qualified material/process review |
| Code shifts or distorts on restart or one format | Bottle orientation, pitch, speed-reference record and inspection view | Presentation/timing and format-specific integration |
| Clear but incorrect date or lot | Approved master data, selected job and changeover approval | Data control; improving contrast cannot correct wrong content |
Retest the approved marking route
This is not an ink, solvent, air-pressure or laser-power recipe. Qualified personnel must follow OEM isolation, chemical, guarding and extraction procedures. Laser trials also require assessment of the actual container and approved marking zone; never bypass a laser enclosure or interlock.
- 01
Retain the original job, approved master data and identified good/suspect samples. Agree the checkpoint and challenge method before a change.
- 02
Compare before/after-contact samples under matched bottle, surface and line-phase conditions. Record both wrong-data and unreadable-code counts.
- 03
Authorize one OEM-permitted change through the responsible specialist, documenting old/new state. Do not simultaneously change ink, bottle and positioning.
- 04
Repeat the agreed startup, steady-run and restart sample windows. Challenge any supplied inspection/reject function safely and record its actual response.
- 05
Have quality review correctness, readability, durability and product segregation together. A successful coder demonstration is not connected-line acceptance.
Request evidence before specifying replacement equipment
If the code exists initially but fails later, define the downstream exposure before replacing the printer. If an independent reference reads it but the inspector rejects it, review presentation and inspection separately. Do not assume either drying equipment or laser marking solves every defect.
Ask Allot Tech for a written boundary covering marking method, approved substrate/zone, retained interfaces, data responsibility, any inspection/rejection supply and a connected sample test. Inkjet and laser need their own material trials; catalog wattage is not proof of bottle compatibility, line capacity or code durability.
- Machine identity and actual inkjet/laser/label route
- Bottle or label drawing, material revision and lots
- Approved message, date basis and job-change record
- Matched checkpoint photos and observation intervals
- Startup/run/restart counts and first damaging contact
- Quality criteria, segregation and proposed supply responsibilities
Questions buyers ask
Will changing to laser stop every date code from rubbing off?
No universal result is established. First identify whether the problem is missing marking, wrong data, positioning or later damage. Direct PET laser needs a substrate-specific trial and a qualified safety/container review, not just a power comparison.
Does code-presence inspection prove the date and batch are correct?
Not necessarily. Presence, readability and correct content are distinct checks. Define what the supplied system actually verifies, challenge it with approved samples and retain an independent comparison to the authorized job data.
Related troubleshooting guides
Water filling machine low output
Water filling machine low output →Water bottle shrink-pack problems
Water bottle shrink-pack problems →Cap leaks after capping
Cap leaks after capping →Wrinkled or skewed bottle labels
Wrinkled or skewed bottle labels →Uneven fill levels and underfill
Uneven fill levels and underfill →Conveyor jams and tipping
Conveyor jams and tipping →Ask Allot Tech to review the evidence
Send your machine identification, package drawing and timed observations. State what is unknown so the proposed scope follows the actual problem.