By Melissa Donovan
Rough, textured surfaces provide a unique opportunity for brand owners looking for an alternative to traditional signage. Multiple printable materials are optimized for application on brick, concrete, cinderblock, or stucco—used either indoors or outdoors. Options include cast vinyl, calendered vinyl, polyurethane (PU) material, and aluminum foil. Each offer characteristics to achieve the user’s desired appearance, remain intact for the duration of the promotion, and remove cleanly and easily.
Above: East Stroudsburg University redesigned its fieldhouse with graphics printed on ORAFOL’s ORAJET 3954 Brick Stone Film and protected with ORAGUARD 290 Premium Cast Laminating Film. Photo courtesy of SevenPiece.
Materials with Conformability
Vinyl-, PU-, and aluminum foil-based media options are all used on rough, textured surfaces. The desired appearance and surface type help determine the best material choice for the specific print job.
In general, “high-conformability products are able to marry to the rough surface, allowing for better adhesion and not taking away from the natural look of the substrate. Without this conformability, they are more likely to tent and separate in a short amount of time,” explains Nate Goodman, product manager, Ritrama Inc.
When choosing a vinyl, cast is preferred over calendered for textured surfaces because calendered films are processed with tension. For this reason they tend to shrink more than cast. “Now when installing on a wall, you can imagine that a calendered film will shrink back to its original state, whereas a cast film will retain its properties after it is conformed and applied,” says Tammy Bui, product manager, Arlon Graphics, LLC.
Jodi Sawyer, market development manager, product branding business team, FLEXcon, agrees. “If a client wants to achieve a painted-on look and the surface is highly textured and rough, cast vinyl provides conformability, elongation, and the ability to withstand installation with a heat gun.”
However, Sawyer cites one disadvantage of cast vinyl is that it can be brittle when installed with heat and break into small pieces when removed, which causes increased time and cost to take down.
“Just as adherence is important, so are the elements of removability. It is key for installers to understand that getting a graphic to stick is half of the challenge. Utilizing vinyl films that remove easily will simplify the typically time-sensitive process and reduce labor costs,” share Beau Hommes, advanced application engineer, and Nate Place, senior application engineer, 3M Commercial Solutions.
“PU film provides excellent conformability to rough, textured surfaces. This allows the film to look more like a painted mural by conforming to the texture of the wall,” says Molly Waters, senior technical specialist, Avery Dennison Graphics Solutions.
PU systems in particular offer premium tensile, elongation, heat resistance, and removability, according to Sawyer. One flaw in these products, in her opinion, is they may be over engineered for shorter term graphics.
“Aluminum foil has a natural ability to conform to irregular surfaces,” explains Sandra Wagner, marketing communications manager, Jessup Manufacturing Co.
Since it is so pliable, points out Micah Causey, VP of business development, FloorSignage, LLC, it conforms to surfaces without the need for heat, which minimizes the time it takes to install. A bonus, it can be disposed of with aluminum—making it environmentally friendly.
Another attractive benefit of aluminum films is how they offer durability and protection even without using a laminate, says Laura Reid, VP of marketing, FDC Graphic Films, Inc.
The adhesive on a material that is eventually used on a rough, textured surface must work well with the film and be durable.
“Depending on how textured the surface is, you want an adhesive that provides as much contact to the surface as possible along with an adhesive that adheres to challenging or low surface energy surfaces. It is important to have a good balance between adhesion and film,” explains Bui.
Bui provides an example of an aggressive adhesive that is so strong that it overcomes the tension in a calendered film. This pairing is a way to solve the challenge of calendered film shrinking back to its original state after installation. Combined with installation techniques that minimize the tension, calendered vinyl is an option for rough surface applications when paired with the right adhesive.
“Selecting a product with an adhesive specifically designed and tested for these surfaces is critical—the peel adhesion to stay on the surface, the right coat weight to ensure adhesive contact, and the optimal shear properties to remove from the surface cleanly are all important considerations,” lists Sawyer.
Adhesive chemistries vary depending on whether it will be used on an unpainted or painted surface. “The material should offer a specially formulated high-tack adhesive designed to grab the exposed textured surface, and work uniformly with the face film when burnished with extreme heat and pressure during the installation process,” suggests Josh Culverhouse, graphic innovations market manager, ORAFOL Americas.
With unpainted surfaces in particular, Culverhouse recommends working with designated films stated for use on unpainted rough and textured surfaces. Conversely, traditional PVC cast vinyl and PU films utilized for vehicle wraps are used on painted brick and block applications. “This is due to the adhesive having a better surface to anchor or adhere to,” he continues.
“Using a high-coat weight and aggressive adhesive meant for low surface energy surfaces allows it to really bite into the nooks and crannies of the rough surface using a vinyl or PU,” agrees Goodman.
A modified acrylic pressure-sensitive adhesive (PSA) works best, in Wagner’s opinion, especially in regards to aluminum foil-based media. This type of adhesive offers good moisture resistance, as water will seep under the graphic. When water does get underneath the decal, the PSA can lose its “grab” on the surface.
Aluminum foil-based media works in tandem with an adhesive, instead of against it. “Aluminum foil does not lift since it has no memory. This allows it to work with the adhesive, holding it in place,” adds Causey.
Proper Install Technique
Most rough, textured surface materials are adhered using a combination of heat and foam roller. Elongation and heat resistance help avoid graphic failure.
“Strength, elongation, heat stability—meaning the ability to be heated and conformed without the film burning and tearing, and ultimately its ability to thermal set so it holds to the rough texture of the walls when an application is complete are all requirements to consider when choosing a film for this application,” explains Jeff Stadelman, marketing manager, Mactac Distributor Products.
For both vinyl- and PU-based products, lay-in versus stretch-in material installation is preferred. The reason for this is best explained using the example of the grout line commonly found in brick and tiled surfaces, which is porous and usually unclean. “Applying the graphic using the lay-in method ensures complete coverage and reduces film tension. Sometimes this graphic gets overlooked and pockets of air are entrapped between the crevices of the textured surface, which allows for expansion and potential lifting when exposed to higher temperatures,” warns Bui.
Vinyl and PU materials are best installed using heat as it makes the material more malleable. “It’s inevitable that some contraction will occur when using extreme heat for adherence. It is important to find a solution that endures extreme temperatures and resists panel contraction,” advise Hommes and Place.
The proper tools are necessary to achieve successful adhesion. Culverhouse recommends a high-end heat gun that can exceed 1,000 degrees Fahrenheit and high-end foam rollers designed for high-heat contact.
“Foam rollers offer equal pressure across the width of the application. The give in the foam allows for pressure to be applied into the nooks of the substrate to help the adhesive grab hold,” says Reid.
Prior to using a heat gun and roller, Waters suggests using a squeegee to set the graphic in place. Then the heat and foam roller can conform the film to the textured surface.
Aluminum foil-based materials don’t require heat to conform to the surface. While heat softens other products to allow them to flow better into crevices and cracks of irregular surfaces, an aluminum foil product is malleable without that aid. “You have the PSA bond in combination with the mechanical strength of the material conforming to the surface,” explains Wagner.
The only tool Causey recommends for installing aluminum foil-based film is a hard rubber roller. This compresses the material to the texture of the wall without friction and achieves a painted-on finish.
Vendors warn that using a media not optimized for challenging surfaces will lead to graphic failure. Issues include the material lifting from the wall and the adhesive losing its stickiness.
“The most common issue is that material will not remain conformed to the texture, allowing air and moisture to get behind it, causing the adhesive to lose its bond. Another issue is that inks can lift off films not intended to conform to texture,” shares Causey.
The failure that Hommes and Place see most often is lifting edges. This is due to poor adhesion on the textured surface. “Not only can this reduce longevity of the graphics, it also results in wasted time and increased labor on the redo,” they warn.
Stadelman adds that graphics could prematurely fade and bubbles and blisters may form under the graphic if a film or combination of films not designed for rough surface applications are used.
Media also could not convey the desired painted-on look and there could be a brittle breakdown of the product in pieces, requiring the graphic to be power washed off the surface, says Sawyer.
Films for rough, textured surfaces like brick and concrete are not new. However, trends in architectural design and functional purposes influence and advance these products. “Using all available surfaces at your disposal to present a message causes manufacturers to think more outside of what they are used to and create better, more dynamic products,” cites Goodman.
Sawyer believes this specific material is becoming a replacement technology for paint. In addition, there is an increased use in urban renewal projects. “This would be architectural applications where building surfaces are older such as brick or unsealed/sealed concrete,” she says.
Architectural trends like buildings constructed from a hybrid of newer materials as well as incorporating older elements influence the use of media for challenging surfaces. According to Goodman, this forces the adhesives in the films to be more aggressive in order to hold to the surfaces.
“We are also seeing plotter cut designs for rough, textured surfaces. This way, the viewer is able to see the rough surface behind the graphic to add an extra industrial or vintage look,” adds Stadelman.
Reflective materials compatible with textured surfaces are trending. “In fact, reflective films are gaining more traction in parking garages and building entry points as oncoming traffic and pedestrians can benefit from added visibility,” say Hommes and Place.
Ease of application is always a concern. “We’re seeing trends to further ease the application of the product through media type, such as aluminum foil-based media, or addressing it through air egress,” explains Bui.
Succeed with the Right Material
A vinyl, PU, or aluminum foil film paired with the right adhesive and dimensional stability can succeed on multiple rough, textured surfaces like brick, stucco, concrete, and cinder block. It’s no surprise that brand owners and media buyers consider this application when looking for ways to differentiate themselves from the competition.
Feb2019, Digital Output