If your shrink wrap machine isn’t producing tight, professional-looking packages, the problem is usually easy to identify and correct. Issues such as poor shrink, wrinkles, weak seals, burned film, or tunnel temperature inconsistencies are typically caused by incorrect machine settings, unsuitable shrink film, or worn components.
This troubleshooting guide explains the most common shrink wrapping problems, their likely causes, and practical solutions to help restore consistent packaging quality.
One of the most common shrink wrapping problems is loose film after it exits the shrink tunnel.
Dog-ears are excess folds of film that remain on package corners after shrinking.
Burn-through occurs when the shrink film develops holes or melts during the shrinking process.
Poor seals can cause packages to open during transport or handling.
Inconsistent tunnel temperatures create inconsistent packaging quality.
If products move too quickly or slowly through the shrink tunnel, the finished package quality suffers.
If the product shifts after shrinking, the package may appear untidy.
Film that tears easily usually indicates either excessive tension or unsuitable film.
Small amounts of odour are normal, but excessive smoke indicates a problem.
If the seal bar leaves uncut film or uneven edges:
Replace worn blades as part of routine maintenance.
Many shrink wrapping problems can be prevented through regular maintenance.
| Problem | Most Likely Cause | Recommended Fix |
|---|---|---|
| Loose shrink | Temperature too low | Increase tunnel temperature |
| Burned film | Temperature too high | Lower temperature |
| Wrinkles | Film too wide | Use narrower film |
| Weak seal | Low seal temperature | Increase seal heat |
| Seal won’t cut | Worn blade | Replace blade |
| Tunnel inconsistent | Faulty thermostat | Check controller |
| Film tearing | Incorrect film | Use correct film |
| Product moves | Oversized film | Select correct film width |
Some issues require professional servicing rather than operator adjustments.
Contact a qualified technician if:
Professional servicing can minimise downtime, extend machine life, and help maintain consistent packaging quality.
Loose shrink wrap is usually caused by tunnel temperatures that are too low, conveyor speeds that are too fast, or using the wrong type or size of shrink film.
Burn-through typically occurs when the tunnel temperature is too high, the product remains in the tunnel for too long, or the film is not suitable for the required shrink temperature.
Wrinkles and dog-ears are often caused by oversized film, uneven heat distribution, or incorrect product positioning before sealing.
Weak seals may result from low seal bar temperatures, worn Teflon tape, insufficient sealing pressure, or a dirty sealing blade.
Basic cleaning and inspections should be performed daily, while more detailed maintenance should be completed weekly and monthly according to the manufacturer’s recommendations.
If you’ve tried adjusting your machine settings and are still experiencing poor shrink quality, weak seals, film burn-through, or other packaging issues, our team is here to help.
At SA Packman, we provide expert technical support, machine servicing, spare parts, and advice to help you minimise downtime and keep your packaging line running efficiently. Whether you operate a manual L-bar sealer, side sealer, sleeve sealer, or fully automatic shrink wrapping system, our experienced team can assist with diagnosing and resolving common machine problems.
Contact SA Packman today for professional support, maintenance services, or advice on optimising your shrink wrap process.
Call us today or complete our online enquiry form to speak with one of our packaging specialists.
