By Jenni Whalen
Pressure-sensitive materials come in all shapes and sizes and are used for a number of different applications—vehicle wraps, signage, graphics for point of purchase advertising, bumper stickers, wallcoverings, and window graphics.
Most pressure-sensitive mediums are designed to bond at room temperature, only losing stickiness in extreme conditions. Engineered to withstand many different environments, they will only last for their intended lifespans with the proper care. This includes preparing the surface prior to installation and conducting routine maintenance.
Prior To and During Application
Installers of pressure-sensitive material must take certain precautions throughout the entire process. Vendors provide a number of different tools, tips, and tricks to ensure success.
3M Commercial Graphics informational materials recommend using masking tape to mark alignment before installing pressure-sensitive materials. This includes floor, window, and vehicle graphics. Grease pencils should be avoided, as the grease can embed in the material’s texture and permanently stain the media.
Floor graphics adhere more strongly if the surface is swept. “If you’re dealing with an indoor tile or sealed concrete surface, a dampened towel will lift any dirt or dust,” says Jason Yard, marketing manager – distribution products, MACtac Distributor Products.
Before installing window graphics, Jim Halloran, VP sales and marketing, Lintec of America, Inc., recommends removing debris from the window with a razor blade. “Windex can be used for cleaning, but be sure to completely dry the surface prior to installation because trapped ammonia can cause adhesives to yellow.”
Halloran also suggests cleaning around the edges of windows with wooden frames in case the wood polish contains wax, which could leach onto the edges of the glass. After cleaning the surface, Yard says isopropyl alcohol removes any film that glass cleaners can leave behind.
ORAFOL Americas provides products for pre-application cleaning of vehicle wraps, which may be helpful for preventing the bubbling or scratching of pressure-sensitive media. The ORACAL 259500030 Pre-Wrap Surface Cleaner decreases and removes cleaning agent residue before the application of a self-adhesive wrapping film. This cleaner can be applied with a soft sponge.
Molly Waters, technical specialist, Avery Dennison Graphics Solutions, recommends using a wet squeegee method when applying vehicle graphics, as this method helps to avoid scratching the vinyl. This means covering the wrap with soapy water, then using a squeegee to remove air bubbles from under the wrap. Avoid leaving the water on the wrap for too long though, as the water can get stuck in the small air bubbles and make installation more difficult.
Squeegees can be purchased through most vendors, but make sure the correct squeegee is used. According to Judy Bellah, PR manager, Clear Focus Imaging, Inc., using the wrong type of squeegee during initial installation or to remove excess water can leave marks on the film. A felt-edge squeegee is recommended to protect against scratches and marring.
A heat gun also helps remove scratches after application. However, it’s important to note that a heat gun can alter the surface of a finish permanently—and many scratches disappear when exposed to sunlight.
Matt Kading, technical service engineer, 3M, recommends—if possible—keeping pressure-sensitive graphics at room temperature for a short time after installation. “If graphic films go outside too soon, the adhesion doesn’t get to set up,” he says. “If things don’t get set up, you’ll have chipped or failing edges. Give it 12 hours at room temperature.”
Keep it Clean
Cleaning is the easiest way to extend the life of pressure-sensitive materials. In fact, most vendors recommend weekly cleaning to avoid the erosion that comes from environmental elements. This involves washing the external surface, as the adhesive backing is no longer open to the air and doesn’t react well to water.
This cleaning can be done with soap and water. Use a soft bristle brush and detergent, but check the pH level of the cleaner before use. Avoid cleaners that are too basic or acidic, aiming for a pH range of between three and 11. Kading suggests using a non-abrasive cleaner. “No strong solvents or acetones, and something without grit,” he says.
Halloran agrees. “Always use soft, clean materials to wash and dry,” he adds. “Never use harsh chemicals or cleaning agents—like Windex—to clean the surface of the adhesive. The chemicals used in harsh cleaning agents can attack the adhesive at the edge of the film causing it to curl.”
On its Web site, Avery Dennison recommends testing any cleaning solution on a small section of a graphic before using it on the entire image. This prevents unnecessary damage. Then, mix detergent and clean water in a cleaning bucket, spray down the graphic with clean water, and begin washing the graphic from the top down to allow dirt and debris to run downward. Once the graphic has been washed, use a garden hose to spray clean water on the material. The graphic can then air dry or be dried by hand with a microfiber cloth.
ORAFOL sells kits for the cleaning and care of glossy and matte surfaces. Each kit contains shampoo, intensive cleaner, a fast care agent, long lasting seal, and special sponges. The products feature recommended pH levels and low grit.
Lintec’s company materials recommend the use of baby shampoo or scentless dishwashing detergent for washing window or wall graphics. When dealing with window graphics, extra care is required. Avoid spraying soapy water directly onto the surface of the adhesive, which can reduce resistance to UV-curable inks. “Spray the soap directly into a clean cloth and then proceed to wipe down the film surface,” says Halloran.
Some pressure-sensitive media—like large signs or graphics on the sides of trucks—might require a pressure washer for cleaning. If this is the case, Waters recommends keeping the pressure below 1,200 psi. “Use a 40 degree angle,” she says. “The concern is that you don’t want to get too close and catch an edge of the graphic. Sometimes we use pressure washers to remove graphics, so keep that in mind and be careful.”
Kelly Kwo, technical service manager, Arlon Graphics, LLC, agrees. “You could lift the vinyl off with high pressure,” she says. “Just wipe the graphics down with soap and water to get the dirt off. That’s safer.”
Pressure washers should only be used on pressure-sensitive media when all other cleaning methods have been tested without success. When working with difficult air pollutants or debris, spot clean the effected area with isopropyl alcohol and a clean rag.
Although vehicle owners may be tempted to take their wrapped vehicles through a car wash, many vendors recommend hand washing, as the seams and edges of an adhesive are susceptible to damage. “Water can seep through the edges and cause them to curl,” says Kwo.
Dean Strohmenger, senior product support specialist, ORAFOL, reminds the company’s customers that car washes are mechanical. “They won’t stop if they grab an edge of the graphic,” he says. If you do decide to use a car wash, make sure it’s brushless.
Wax is another concern for vehicle wraps. Most pressure-sensitive media reacts badly to paste waxes—the image will haze—so check the bottle before applying wax. Waterless wash or spray waxes probably won’t ruin the wrap, but most vendors caution against the use of any waxes or polishes at all, especially for graphics with textured finishes.
In hot climates, dust and debris settle on pressure-sensitive media and bake in, causing the horizontal areas of the media to fail. Often, owners will notice browning or cracking.
In fact, 3M offers a reduced warranty for pressure-sensitive media sold in the desert because of UV damage and extreme heat. These graphics are intended to last for seven years, but have a three-year warranty in hotter climates.
If UV damage or hot weather is a concern, Yard suggests laminates help prevent premature aging. But graphics in harsh conditions will always have shorter life spans. To lengthen the lifespan of pressure-sensitive materials, store objects indoors as much as possible and clean even more frequently than you already would.
“A controlled environment helps a graphic last longer,” says Yard. “The more often it gets hot or cold, the weaker adhesives become.”
It’s also important to consider environmental contaminants. Strohmenger recommends rinsing vehicle wraps, window graphics, or signage after a rainstorm to remove elements like acid rain. “Also, spot cleaning after exposure to things like bird droppings,” he says. “You want to clean it off right away.”
Kwo points out abrasion as an issue, especially for vehicle wraps. “Once you wrap a car, the film isn’t abrasion resistant,” she says. “If you put luggage on the bumper, you may scratch the vinyl. It’s not paint, so you have to be gentle to make sure you don’t destroy it.”
The Bottom Line
When dealing with pressure-sensitive media, it’s important to first apply the materials correctly. Without proper application, they may be susceptible to curling, cracking, or blurred edges. Clean the surface before application, and use a kit to make application easy, avoiding bubbling or scratching in the process.
Moving forward, cleaning the media frequently by hand with soap and water will push graphics to the end of intended lifespan and often beyond. Humidity, extreme temperatures, or environmental pollutants can shorten the lifespan of pressure-sensitive media, although laminates will help ensure that the graphic will last for the appropriate amount of time.
Click here to view the Printable Pressure-Sensitive Materials Target Chart – an all-inclusive information resource!
Sep2014, Digital Output