How many times have we heard that pressure-sensitive or cold laminates are too expensive to use when compared to thermal laminates? When you look at the actual costs of thermal laminates as well as differences in application and performance issues, this assumption doesn’t necessarily stand up—particularly when laminating vinyl-based products or water-based inkjet media.
In fact, most manufacturers of water-based and solvent media recommend that pressure-sensitive laminates be used due to better bonding and the need for only single-sided lamination protection.
Consider Application Needs
When evaluating the pros and cons of thermal laminates versus pressure-sensitive laminates, determine what media will be used, type of lamination needed for the application, and finally, the projected cost.
The material being printed on is important to your lamination choice. Thermal laminates can affect the performance of adhesive backed and vinyl-based products. With adhesive backed media, the heat applied to thermal laminates can lead to adhesive failure by causing premature curing of the adhesive and the loss of adhesive peel strength. Vinyl media doesn’t like heat, and thermal lamination can cause abnormal shrinkage and media failure. Gloss-based media such as photo gloss paper may also react adversely to thermal laminates by not adhering well due to the composition of water-based inks. Meanwhile, pressure-sensitive laminates will adhere well to virtually any material without heat.
Looking at the application is very important. Consider whether your finished product needs to be flat or curved, rolled-up for shipping or storage, or used indoors or outdoors. Prints finished with a pressure-sensitive laminate are flexible and roll easily; prints protected with a thermal laminate, however, don’t roll easily. For images such as trade show graphics and POP displays, which typically must be rolled for transportation and storage, the need for flexibility is very important. Because of the rigidity of thermal laminates, pressure-sensitive laminates are more appropriate. If flexibility is essential for your project, you can also look at pressure-sensitive laminates that are designed for curved applications such as vinyl. Most pressure-sensitive and thermal polyester films (polypropylene and polycarbonate films) are better suited for applications where media is applied to flat rigid substrates.
Because most prints are laminated to protect from being scratched or defaced, rather than to protect them from moisture, one-sided pressure-sensitive lamination typically offers sufficient protection. The most commonly used pressure-sensitive laminates are cast and calendered vinyl films in 2 to 3.5 mil thickness in matte, satin, luster, and gloss finishes. Other regularly used pressure-sensitive laminates are polyester films, polypropylene films, velvet polycarbonates, and various textured and rigid films, and can be purchased in up to 15 mil thickness if needed.
Weigh the Investments
When comparing costs between thermal and pressure-sensitive laminates, consider that most thermal laminates require you to laminate both sides of a print. Encapsulating a print between two layers of laminate automatically doubles your material usage and, therefore, increases your cost.
You will also need to factor in the costs of the equipment. Thermal laminates require an investment in a hot laminator, which is an expensive piece of equipment to purchase and maintain. A pressure-sensitive laminator can cost over 50 percent less, and has fewer additional maintenance costs. Pressure-sensitive laminators can also be used with most 110 outlets while thermal laminators require a 220 outlet.
Follow the Rules
The same rules apply to mounting your media when using pressure-sensitive or thermal mounting films. Regardless of which laminating method you decide to use, it is recommended that you allow your print to dry for at least 24 hours prior to lamination. Certain media may require the ink to dry longer.
Without following the appropriate procedures for laminating your prints, a few problems may arise. Delaminating is likely to occur when laminating graphics while the ink is not fully dry. Blistering may also take place. This is when the inks are, again, not fully dry and the print is then exposed to excessive heat by roller temperature or speed. Inadequate pressure when laminating can cause poor adhesion and silvering of your media, giving the surface of the laminated print a silver or hazy appearance. For these reasons, it is very critical that you laminate a print at the right time, with the appropriate roller temperature and speed.
The Bottom Line
Before making a choice between thermal laminates and pressure-sensitive laminates, ask around, shop around, and get the facts. Don’t avoid using pressure-sensitive laminates because you’ve heard they’re too expensive. Many companies sell pressure-sensitive laminates that are cost-competitive with thermal laminates and provide excellent protection. You owe it to yourself, and your customers, to investigate and understand all of your lamination options.