Key Takeaways
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.
Our own technicians service the machines we supply, with spares held in Johannesburg.
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.
How the sealing stage works is explained in how shrink wrap machines work.
Inconsistent tunnel temperatures create inconsistent packaging quality.
The shrink tunnel page explains how tunnel heat and airflow are set.
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.
Most shrink wrapping problems are prevented by routine maintenance: cleaning the seal bar and removing film residue every day, inspecting heating elements, checking temperature calibration and cleaning the tunnel fans every week, and replacing worn Teflon tape and checking belts and rollers every month. The full daily, weekly and monthly schedule is in the shrink wrap machine maintenance guide.
| 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 |
Call a service technician when a problem keeps coming back after the settings have been corrected, or when the fault is electrical or mechanical rather than a setting. That includes heating elements that fail repeatedly, temperature controllers showing errors, electrical breakers that trip, conveyor motors that stop unexpectedly, sealing mechanisms that have become misaligned, and a machine that still produces inconsistent packs after routine adjustments. Professional servicing shortens downtime, extends the life of the machine and keeps pack quality consistent.
Every machine we supply is installed and commissioned by our own technicians, who also service it, and spares are held in Johannesburg to keep downtime short. Contact us for service or a technician visit.
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 adjustments have not fixed the problem, our own technicians can service the machine, with spares held in Johannesburg to keep downtime short. Every machine we supply carries a one-year warranty and can be CE marked on request.
