by Digital Output Staff
Digitally printed wallpaper, wall graphics, and wallcoverings are often subject to wear and tear in environments from offices to retail. Whether in a commercial or residential space, the image may be touched or splattered with a cleaning solution, food, or some other contaminant.
Film laminates are a consideration for protecting wallcoverings, in addition they can enhance the aesthetic of the graphic with a specific texture or visual overlay. Another alternative is liquid coating. Both options offer advantages. Choosing between one or the other depends on environment, longevity, and media type.
Above: CKL Wraps printed this wallcovering using Avery Dennison MPI 2611 Matte Removable Wall Film.
Fluid and Stagnant
Wallcoverings are placed in a number of different environments for short and long periods of time. A liquid coating is sometimes preferred over a film laminate and vice versa. In addition, paper- and pressure-sensitive adhesive-based materials dictate whether a liquid or film is required.
Liquid coatings are ideal for use when a wallcovering includes textured or raised elements. Paul Roba, OEM relationship manager, Avery Dennison Graphics Solutions, says this is because the liquid can cover “peaks and valleys.” These can come from either textured media or if UV inks are used, as they can convey a textured finish, he shares.
With the liquid coating filling in those peaks and valleys, the result is a smoother, more natural look, according to Ash Weekley, business development manager, wide format and graphics, Mac Papers. He adds that the process of applying a liquid coating is generally less labor intensive, but does require a skilled operator.
Another benefit of liquid coating, it’s easy to apply after the wallcovering is completely installed, shares Lisa Schultz, operations manager, DreamScape. So, if protection or a certain aesthetic finish is an afterthought, adding a liquid coating can help meet the desired goal even after the material is applied.
Film laminates are also used to protect or enhance wallcoverings. For many, using a film laminate actually adds dimension instead of downplaying texture like a liquid coating might do. “Pressure-sensitive adhesive film overlaminates provide a more consistent finish and are ideal for adding unique dimension to traditional wall graphic applications. You can create the unexpected with film overlaminates by mixing different finishes into the equation,” suggests Josh Culverhouse, graphic innovations market manager, ORAFOL Americas.
That added layer of film also provides enhanced protection against the elements. “For environments such as wall graphics and/or coverings where longer term use and resistance to damage are important, film laminates offer superior resistance to chemicals, solvents, moisture, humidity, and abrasion as well as UV resistance to prevent fading,” recommends Jodi Sawyer, marketing development manager, product branding business team, FLEXcon.
Brian Biegel, marketing communications specialist, D&K Group, points out that matching the print media with the correct overlaminate or coating is essential to avoiding graphic failure. For example, a vinyl-based print media benefits from a vinyl-based overlaminate.
“Vinyl wallcoverings—especially those located near windows or heat sources—may require a vinyl laminating film rather than a liquid coating. A vinyl laminating film and the vinyl print media both expand and contract at the same rate when the temperature changes. This helps prevent the coating from cracking or popping because the materials share similar properties,” he explains.
Film laminates are also helpful because the extra layer of material adds some rigidity to the wallcovering, making installation and removal of the graphic easier, shares Tim Boxeth, marketing manager, 3M Commercial Solutions.
There are a number of ways to apply both liquid coatings and film laminates—foam roller, spray, or laminator. Manual, semi-automatic, and automatic are additional considerations. With a wallcovering, the overall surface area may dictate which method works best.
Shorter runs and one offs benefit from manual application of a liquid coating. For example, Schultz suggests applying liquid coating using a 0.25-inch nap paint roller, manually rolled over the image using a thin, even coat. This method is ideal for when the graphic is already applied to the wall.
“For smaller areas, spray can be used but it does not produce as consistent of a finish,” cautions Weekley.
There are automated roller coaters that apply liquid laminates. “Typically, longer production runs utilize the roller coating process for less labor and simple application. This process provides even, consistent coverage,” suggests Roba.
Pressure-sensitive film overlaminates are best applied using a cold roll laminator. Heat is generally not required in this scenario, according to Sawyer, because the adhesives used in the pressure-sensitive film require pressure and not heat for activation, she explains.
A heat assist or thermal laminator is really only required in a situation where a specialty-type film is only available as a hot laminate or if a thermal option is requested, adds Weekley.
“A laminator provides even and consistent pressure when applying protective films to wallcoverings. This method reduces wrinkles and trapped air pockets, also known as silvering, between the wallcovering and film layers. Some laminators also offer roll-to-roll processing capabilities to easily and efficiently apply film laminates to long rolls of printed material,” says Biegel.
Certain laminators can also apply adhesive—this broadens a print provider’s media selection in relation to wallpaper applications. “Most roller laminators can simultaneously apply a protective laminating film to the front of a wallcovering and a two-sided mounting adhesive to the back of the material. This allows graphic providers to produce wallcoverings using paper media rather than self-adhesive paper or vinyl,” shares Biegel.
Roba admits that film laminates can be hand applied, but the best results are with multi-roll or flatbed laminators.
Looking strictly at the cost of a liquid coating versus a film overlaminate is difficult, as the investment is more than materials. The cost of labor is also an important consideration.
“Part of the cost of a liquid coating is paying someone to apply the coating after the material has been applied to the wall,” says Mark Elvester, senior application engineer, CSD application engineering, 3M.
Roba agrees and says that while liquid coating is typically less expensive than film laminates, “the cost differential is absorbed into the overall cost of production and passed through to the ultimate end user.”
For example, the cost of DreamScape DreamGuard to the print provider is approximately $0.08 per square feet plus the labor to apply the liquid coating.
According to Weekley, liquid laminate costs are $0.03 to $0.05 per square foot and end user pricing should be between $0.04 to 0.07 per square foot. Film laminates can be from $0.12 to $0.22 per square foot, adding in labor cost to the provider is close to $0.50 per square foot. End user pricing should be $0.70 to $1 per square foot.
“Film laminate costs vary depending on the volume and type of material used. Many standard pressure-sensitive laminating films cost print providers approximately $0.10 to $0.15 per square foot. Thermal laminating films offer a more inexpensive finishing solution for as low as $0.03 cents per square foot,” shares Biegel.
Boxeth says laminates typically range from mid $0.60 to $1.05 a square foot depending on performance and appearance.
UV-curable and LED ink sets are paving the way for applications that require no coating or overlaminate. For wallcoverings, despite these advances, liquid coatings and film laminates are still used for many reasons—ease of installation, building code specifications and health-related issues, protection from abrasion, and enhancement of the graphic.
“It’s definitely a preference whether or not to laminate an interior wall graphic, but installers appreciate having an overlaminate applied. Overlaminates provide additional support or structure to the graphic during installation to the wall. This makes panel alignment much easier for the installer as the panels are less likely to overstretch or sag,” shares Culverhouse.
Another benefit, coatings or laminates can further booster eco-friendly certifications, more specifically in environments like hospitals or childcare centers. “If the print is going to be in a nursery, hospital, or nursing home environment and solvent or eco-solvent is used, even with GREENGUARD Gold certifications, I would still recommend coatings,” says Weekley.
“The addition of these protective coatings and laminates can also help meet specifications for building codes, such as ASTM, NFPA, and other building code safety requirements,” agrees Roba.
Some overlaminates, Sawyer points out, help prevent the spread of germs by inhibiting the growth of bacteria on the surface.
Schultz admits that UV inks are quite durable, and unless the wall graphic is in a super-high traffic area, an additional liquid coating topcoat to prevent abrasions and scuffing may not be required. However, latex- and solvent-based images may require additional protection. “Latex and solvent ink printed images would generally benefit from an application of a liquid topcoat to help prevent abrasions and/or scuffing in high-traffic areas,” she adds.
“Although the quality of inks is improving and some inks are adding anti-scratch coatings to their formulations, you will not have the same abrasion resistance, UV resistance, or color fastness that you can get with a film laminate or liquid coating,” admits Roba.
Boxeth notes that if a wallcovering or wallpaper is applied without a coating or laminate, and it is washed or wiped down, sometimes the ink will become scratched or smudged.
“Although film laminates are often best known for their protective qualities, they can also be used to enhance the graphic in ways that neither films nor inks can accomplish on their own. Take for example the range of finishes and textures available. Fillers can be added to liquid laminates to create a matte look, however, a variety of finishes—from matte to embossed/textures—reduce glare from direct lighting on a vertical surface and add a unique look and feel to match the look of a particular texture, such as brick,” concludes Sawyer.
Wallcoverings benefit from either liquid coating or film laminate depending on the environment, length of the application, and base media type. While not always required, they are recommended to achieve optimal protection or enhance appearance. “The location, performance expectations, and print materials used dictate whether or not a protective coating is necessary. A liquid coating or film laminate adds a cleanable surface that protects the printed material below, while also enhancing the look and feel,” concludes Biegel.
Feb2019, Digital Output