Using too much tension when applying the overlaminate to the magnetic sheet can result in delamination.
+ Tension Issues. This happens when you use too much tension when applying the overlaminate to the magnetic sheet. This will pull the magnet (creating a “curling” effect). Your end-result will be delamination. Solution: Use the lowest tension settings to allow the product to lay flat. “Test a small piece first with the overlaminate process and the least tension setting,” says Sheridan. “Let the magnet relax to ensure that it lays flat.” + Heat Issues. Be careful that you’re not using too much heat. And if you have to apply hot glue to the back of a laminate, this can cause the vinyl to shrink—thereby cracking the magnet and damaging the laminate. Solution: “Instead of hot glue, use a pressure-sensitive overlaminate (like a peel-and-stick),” remarks Sheridan. + Adhesion Issues. The overlaminate being used isn’t consistently sticking to the mounting substrate. Solution: “Use consistent pressure when you apply the overlaminate to avoid inconsistent stick,” says Sheridan. “If the overlaminate doesn’t stick consistently over the printed parts of the mounting substrate, you need to pay attention to the ink coatings. The ink flood coat can cause the overlaminate to stick differently than the unprinted surface.” + Magnetic Memory Issues. When approaching the end of the roll, you may find that the magnet will not lay flat for 64
Sign Builder Illustrated // July 2013
printing. This is because the magnet is rolled on a three-inch core, which means the magnet will curl due to “memory.” Also you can find bubbles in the middle of the roll when approaching the end. Solution: “The magnet will need to lay flat for a little while to relax before printing,” suggests Sheridan.
Final Exam: Storing Flexible Magnet Sheeting Most magnetic media is safe to store for one year, but keeping this material in your shop (whether in flat sheets or rolls) requires a low humidity and a constantly cool storage area. “What also helps in storing magnetic material is to buy material with a clear protective coating on the back side of it to prevent it from adhering to other magnetic material while being stored, otherwise known as ‘blocking,’” says De Leon. “This clear coating will also prevent the promotional magnet from sticking to its mounting surface, as long as normal cleaning procedures are followed.” Once you’ve finished printing onto the magnet, lay the product flat until you’re sure the ink is completely dry. “Then if you’re going to roll the magnets after print, always roll onto a cardboard core with the printed side facing out,” states Thompson, noting that this will prevent the curling effect from taking place on the applied surface. (Note: And be sure to store the finished magnet in a container, so the exposed graphics won’t get damaged.) Remember earlier when we said to store magnets in a constantly cool area? Well you have to make sure the room is not too cool. signshop.com
all photos: magnum magnetics.
ditional problems and solutions: