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Proper Lamination Techniques

Have you ever felt like just crushing your wide-format laminator? Many have at some point or another, especially when it seems like some sort of ghost inside the laminator keeps ruining your images! Waves, wrinkles, silvering, bubbles, curling and other unwanted effects can stress a shop owner time and again.

Well, take heart. In this article we’ll show you some laminating techniques, tips and tricks that may just make you fall in love with your laminator again.

Tip #1: Choose Your Equipment Carefully

Let’s begin by simply stating that not all laminating equipment is created equal. Some are simple, and some are quite complex. Some are made in the USA, some not. Your choice in manufacturer and quality can make the first difference in operating efficiency.

So the first tip? Choose your laminator carefully. Research the company as well as the machine and spend a little more money to get the quality needed in the equipment from the beginning. If you start with poorly made equipment, none of the following techniques will help much.

Tip #2: Web Your Laminator Properly

Webbing or threading is the process of adding your laminating film and media to the laminator and then threading it between the rollers. If done improperly, the results can be drifting of the film over the image and other negative effects.

Here’s a typical diagram of a simple laminator doing a single sided lamination application. Laminating film is added to the supply shaft. The backing paper is removed from the film and attached to a take-up reel. The exposed film is then routed through a roller that will eventually press it onto the image.

The critical technique here is to make sure that both the film and image are flat against the rollers before closing the rollers. Check for tiny gaps at either end of the media/roller or film/roller edges.

Of course the film and imaged media must also line up properly at the edges to avoid film drifting over the image. We would also recommend a generous margin be placed along each edge of the image to allow for this drifting. If the laminator is properly aligned and webbed, drifting should be minimal in a quality machine. (Note: Some lesser-quality machines may have roller alignment issues that may require a service call and adjustment to the rollers.)

Tip #3: Use the Correct Take-Up Tension and Film Supply Brake

One of the most common reasons for film wrinkling—where the film begins to form waves over an image and subsequent wrinkles—is using too much brake and tension. Every laminator must provide some brake on the supply shaft to keep the laminating film tight against the roller. Likewise when the laminating film backing paper is released from the film, there is a need for some tension in the backing paper to prevent it from entering the rollers. Too much of either can cause problems.

As a rule, less of both brake and tension is better. All that is needed is enough brake to hold the film firmly so it stays flat against the roller and enough tension on the release liner to make sure it doesn’t catch beneath the roller. Start with a little and slowly add more brake and tension until the film is tight against the roller and the backing paper releases from the film just before going into the rollers. Keep an eye on both settings as the job runs as adjustments may be required. If each is set properly, the film should release from the liner and adhere to the image perfectly.

Tips #4: Apply Just Enough Pressure

It’s a good idea to apply just enough pressure to make sure the film will adhere to the media. Now, this can be light pressure if applying film to a media such as vinyl, but more could be needed if applying a film to a rigid substrate. The operator will have to get a feel for the procedure. However, as a guide, remember this—just enough is enough! It is not necessary to add excessive pressure to set a film to the media. In fact, too much pressure can increase the chance of effects such as "boat-waking" waves.

Most high quality laminator rollers are slightly crowned, meaning they are slightly thicker in the middle of the roller than at the ends. When the proper pressure is applied, the footprint becomes even from roller-end to roller-end. Applying too much pressure can make the footprint uneven and result in negative effects.

If the laminator has a manual control for pressure, then the operator can vary the pressure, even during a job, to keep negative effects such as boat-waking from occurring.

Tip #5: Use the Right Film/Media Combination

It is vital to match the laminating film with your media type. Using a non-polyester film with a polyester media can result in delaminating and other negative effects. The best way to ensure that the film and media match is to purchase your film from the same company where you purchase the print media.

Tip #6:

Allow for Ink Curing

Another reason for delamination can be poorly cured ink in the print itself. In today’s wide format print world eco-solvent ink is very common. It is recommended that all prints are allowed to dry/cure for 24 hours before it is laminated. All too often, shops get in a rush and laminate too soon.

If a graphic is laminated too soon, gasses from inks that are trying to cure can continue to escape from the print, but the laminate prevents them from being released and—you guessed it—delaminating occurs. This is why it’s important to allow sufficient time for images to cure before laminating. However, with UV-curable and latex inks this is less of an issue. UV-curable and latex ink prints can be laminated immediately.

Tip # 7: Slow Down and Use a Little Heat

One of the best tips I can give you is this: Slow Down! Everyone wants to run their jobs at full speed, but a long history of experience tells us that when it comes to lamination, slower is better. Think of it this way: If you press a piece of masking tape onto a table for one second and another piece for five seconds, which one would you expect to adhere better? Of course it’s the one pressed down longer. The same is true in laminating.

The longer the film is pressed on the image the better it will stick. In fact, this will also limit “silvering”, an effect where the laminate sticks to the image but leaves behind a slight foggy look created by micro-bubbles.

Silvering will not really effect the final product and in fact may even disappear after 12 to 24 hours. One way to help eliminate silvering is to use a little heat (90-100° F) to warm the roller while laminating. In some cases, this will completely eliminate the silvering. Using a little heat to help adhesion and eliminate slivering is especially effective when applying a cold laminate to self-adhesive vinyl. The heat warms the adhesive, making it softer and more pliable. Using heat combined with a slower running speed will get you optimum adhesion resulting in a clear application of the laminating film.

Many laminators come with heated rollers, but some do not, so make sure you consider carefully what applications you will run before purchasing a laminator. Spending a little more money to get a heated roller is a wise investment.

Tip #8: Get Proper Training

Finally, we would like to recommend that you get proper training on how to use your laminator. Your reseller or even a third party company can spend just a few hours with you and improve your techniques dramatically. Learning the right techniques in laminating is simply the best way to fall back in love with your machine.