Laminating machine problems usually go something like this…“How do I get the film to stick properly?” and “How do I stop getting bubbles under the film?”
These are 2 of the most common troubleshooting questions printers ask me about laminating, and they reflect a lot of pent-up frustration.
After all, finishing issues like these delay jobs, waste film and waste stock. So how do you solve them? In this blog post, I give basic solutions to these problems and more. Use these mini-checklists to help you streamline production and give your customers better quality.
1. The film isn’t sticking
This is particularly common with digital print, and it’s because of the ink composition and the way inks bond to the adhesive. The denser the ink coverage, the harder it is to get the film to stick.
- Use the right film – Films react differently to different stocks, inks and machines because no film is universal. Start by choosing the right one for the print job (get advice on this!). Sometimes you might even need encapsulation film, check out my article about the differences between encapsulating and laminating.
- Turn the machine on early so it’s full of heat – Often, printers turn the machine on right before they want to use it. When you start laminating from cold, you risk having different temperatures on parts of the roll, which affects the quality of the finishing. If you have cool spots on the product, it means there’s an area on the roll that’s not hot enough to melt the adhesive
- Make sure the ink is dry – Leave time for the print to cure before laminating. When you try to finish straight off the back of digital print, you’re more likely to have issues with film sticking
2. There are bubbles under the film
Bubbling is generally a combination of many factors, so there’s no single quick fix.
- Adjust the tension on the feed spool based on the film spec – If there’s insufficient tension, air can get trapped between the film and the print. The correct tension depends on the film (the thicker the film, the more tension it needs), so check the specification
- Feed more slowly – You shouldn’t feed the print into the machine faster than the laminator speed
- Make sure the ink is dry – This is the same as with the issue around film sticking. It’s one of those instances where waiting saves time in the long run
- Ensure there’s a consistent temperature – When you have hot spots on the rolls, the ink can boil. If bubbling is due to hot spots, make sure you’re not leaving the machine idle for long (so roll temperature stays consistent), speed up the laminator and try reducing the temperature slightly.
3. The print ends up with orange peel
If you’re finding fine wrinkles or waves, it’s usually because the machine is too hot.
If you laminating film is becoming wrinkled you may need to reduce the temperature
- Temperature – Use the recommended working temperature for the particular film
- Speed up the laminator – This is worth trying as a quick fix, because when you run the film faster it doesn’t heat up as much
- Change the film – Sometimes you get orange peel when the prints have solvent residues, so use a film that’s suited to this situation
4. The print won’t lie flat after encapsulating
A bit of print curl is normal but should resolve with gentle smoothing. If this doesn’t work, try to:
- Adjust the laminator tension – If you use the same tension for the top and bottom films, the bottom will end up stretching more during laminating and then tightening more during cooling (which causes curling)
- Use the right film on both sides – Curling can happen when there’s a heavy film on one side and a thin film on the other
5. There are marks on the print
This is usually due to something stuck on the roll or a feeding issue causing the image to distort.
- Clean the rolls – Repeating marks are usually caused by adhesive, film or paper sticking to the roll
- Feed the print parallel to the roll – This helps prevent infeed waves
6. The film keeps wrapping around the rear rolls
This is a particular problem with lighter films, and it’s because of the effects of static electricity. You can gently pull the wrapped film off the rear rolls by running the machine in reverse. To prevent the problem:
- Laminate in a continuous feed – The weight will help hold the film away from the rear rolls
- Leave a few inches of extra film between each sheet if encapsulating – This also adds weight, which mitigates the effects of static trying to pull the film back
- Ground your machine – Not only is this a safety issue, but it also helps drain off static from partial conductors
- Use tinsel – this is the most common way of neutralising static, but make sure you choose one with a metal core, stretch it tight, place it 0.25 inches from what you want to neutralise and give it free airspace
Laminating isn’t an exact science
There are lots of pitfalls, which is why it’s good to get expert advice – particularly as ink and stock keep changing. I estimate that when I help printers troubleshoot their laminating, 60% of the time it’s operator error, 20% of the time it’s the wrong stock and 20% of the time it’s the wrong choice of film.
Get in touch for some free support if you have more questions. Give me a ring on 01179 414 999 or email me at firstname.lastname@example.org.