L sealer machine UK
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Shrink tunnel guide
Shrink tunnel airflow guide
Shrink tunnel airflow influences how evenly the film shrinks around the pack. Temperature alone is not enough for a good finish.
When this search applies
Shrink tunnel airflow influences how evenly the film shrinks around the pack. Temperature alone is not enough for a good finish.
- Airflow around all pack sides
- Temperature and speed balance
- Avoid overheating products
- Consistent pack spacing
Airflow and presentation
A poor finish may be caused by airflow, speed, film type or pack spacing rather than temperature alone. The tunnel should be adjusted as part of the whole process.
Product protection
Sensitive products need careful control so shrink film tightens without overheating the carton or contents.
Information to send for an accurate recommendation
| Pack dimensions | Largest and smallest product sizes, pack weight, stability and whether products are single cartons, bundles or trays. |
|---|---|
| Required output | Target packs per minute, daily volume, shift length, changeover frequency and whether future output may increase. |
| Film and finish | Preferred shrink film if known, presentation requirements, seal position, retail display needs and barcode visibility. |
| Line layout | Available floor space, infeed method, conveyor height, power, compressed air and whether a shrink tunnel is needed. |
FAQ
Shrink tunnel airflow guide FAQs
Should I simply increase temperature?
Not always. Higher temperature can distort film or damage products if airflow and speed are wrong.
Does pack spacing matter?
Yes. Packs too close together can block airflow and cause uneven shrink.
Can this be solved during setup?
Often, yes. Trial settings help find the right balance.
Related pages
Next steps for shrink wrapping machinery buyers
Use these pages to compare L sealers, shrink tunnels, film route and quotation requirements.
Automatic L-sealers
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L sealer with shrink tunnel
Understand when a combined sealer and tunnel route is the best fit.
Shrink wrapping machines UK
Compare L sealers, chamber machines, tunnels and wider packaging routes.
Specification checklist
Prepare product and line details before requesting a quotation.
Get a quotation
Send pack sizes, output target and film needs to Lancing UK.
Tunnel airflow
Why airflow matters as much as tunnel temperature
Airflow distributes heat around the film. If air only reaches part of the pack, one face can shrink cleanly while another remains loose, wrinkled or overheated. For L-sealer lines, the tunnel should be assessed with real product spacing and the actual film because both influence how heat reaches corners and underside areas.
Temperature alone is not a reliable setup method. Belt speed, product spacing, tunnel loading, aperture size and cooling after discharge all change the finished result. A useful test records the settings that created the best pack so the operator can repeat them.
| Selection point | What to confirm | Why it matters |
|---|---|---|
| Air direction | Observe whether corners and underside areas shrink evenly. | Uneven air movement can create dog-ears and loose film. |
| Product spacing | Run products at the spacing expected in production. | Crowded packs can disturb airflow and reduce repeatability. |
| Tunnel loading | Avoid judging results from one isolated pack if production will run continuously. | Continuous loading can change temperature stability and airflow behaviour. |
| Cooling zone | Inspect packs after cooling, not only at tunnel exit. | The final appearance can change as film stabilises. |
Information to prepare before a quotation
- Film type and thickness.
- Pack dimensions and spacing.
- Tunnel temperature and belt speed used in the trial.
- Airflow observations around corners and underside.
- Final pack quality after cooling.
Temperature problems
Troubleshoot loose film, overheating and inconsistent shrink.
Tunnel size
Check tunnel aperture and product clearance.
Finished pack quality
Review seal and shrink presentation defects.
Buyer FAQs
Why does one side shrink better than the other?
Uneven airflow, product spacing, film allowance or pack shape can cause one-sided shrink.
Can more temperature fix wrinkles?
Not always. Excess heat can damage film or product; dwell and airflow may be the actual issue.
Should packs be cooled before judging quality?
Yes. Finished appearance and handling strength should be checked after the film has stabilised.
Does product spacing matter in the tunnel?
Yes. Spacing affects how air circulates around each pack.
What trial notes are useful?
Record film details, temperature, belt speed, product spacing and the observed result.
Related guidance: Heat tunnels · Troubleshooting guide · Sample testing