By Cassandra Balentine
Rigid substrates are often associated with being heavy and thick, ideal for longer term applications. However, as lower density options enter the market and gain popularity, the opportunity for boards evolves. In addition to lighter weights, features such as added textures and special effects like glow-in-the-dark properties further the reach of rigid substrates.
Above: Both Vycom DigiLite White and DigiLite Black provide brilliant color pop across all flatbed printer platforms.
Expanding Role
The role of rigid substrates expands as properties like added texture, special features, lighter weights, and lower densities come into play.
As the polymer industry grows, Mike Sherrod, market development manager, Vycom Plastics, points out that new offerings in rigid media are available. “Previously, white expanded PVC sheets were the only choice, with colored sheets introduced shortly after that. Now there are a range of textures and finishes. For example, Vycom manufactures Celtec Woodgrain, which features a wood-like texture for print service providers (PSPs) to offer alternatives to their customers.”
In another example of specialty rigid options, American Permalight, Inc. offers photoluminescent rigid PVC substrates that provide high-performance, glow-in-the-dark properties that are UL1994-listed by Underwriters Laboratories, Inc. (UL).
“Our Permalight rigid PVC substrates are code compliant and suitable for creating photoluminescent staircase identification signage,” says Marina Batzke, GM, American Permalight. She points out that this is important following building code improvements that came following the 9/11 tragedy in New York, NY. The nationwide requirement involves installing non-electrical, photoluminescent egress path markings in high-rise buildings. “Floor identification signs are part of this enforcement, which requires each access floor inside the enclosed emergency staircase to have one identification sign, which is photoluminescent, and a minimum of 12×18-inch dimension installed.” The building code spells out the exact sign text details, including letter height and required text message. The floor level is raised plus has braille underneath.
Batzke says Permalight offers five different glow durations from Basic Glow to Permalight rigid PVC substrate SKUs, including 81-1066 and 81-1077, which carry the UL1994-listing and are used by sign makers nationwide to add raised floor-level numbers/letters and braille beads inserted underneath. She says to give the 0.046-inch thick Permalight rigid PVC a thicker firmness, sign makers typically mount the 46-mil thick rigid to an opaque, non-glow backing.
Low Density
One change to rigid boards is the availability of lower density options. Lower density rigid substrates have become more prevalent over the years as digital flatbed printing equipment has evolved.
“The print platform is more accessible, and the quality continues to improve. This has led to experimentation and new types of everyday applications that may have featured more ‘traditional’ media options in the past,” says Sherrod.
There are many low-density materials such as polypropylene, styrene, and foam sheets but for digital printing, expanded PVC is the primary material, he shares.
Vycom considers its Celtec Expanded PVC and Celtec DigiLite to be standard and low-density foam PVC products, respectively. Celtec Ultra White is considered a solid PVC offering. The comparative specifications are Celtec DigiLite featuring a 0.48 grams force per square centimeter (g/cm2) density—tolerance of +/- 0.02—and thickness of three and six millimeters (mm); Celtec with a 0.58 g/cm2 density and one to 38 mm thickness in white, one to 25 mm in black, and three to 12 mm in colors; and Celtec Ultra White with a 1.42 g/cm2 density and two, three, and six mm thickness.
DigiLite is the newest addition to the Celtec family of products. Three characteristics set DigiLite apart from the competition—printability, ease of fabrication, and recyclability.
Sherrod points out that both DigiLite White as well as DigiLite Black provide brilliant color pop across all flatbed printer platforms. And in terms of fabrication, he says users can achieve smooth, clean cuts that deliver a professionally finished look. Further, the products are also 100 percent recyclable. “Through Vycom’s PVC and acrylic recycling program, users can now properly and effectively dispose of printed or unprinted scrap and end-of-life/use PVC sheets, preventing these items from ending up in landfills. This scrap will be reused for products manufactured by The AZEK Company, parent of Vycom,” he explains.
Vycom’s high-density printable products include Celtec and Celtec Ultra White, the latter being the highest density offering. “This is a solid construct PVC sheet that can stand up to four-season weathering while maintaining the ability to be die cut and thermoformed,” notes Sherrod.
He points out that similar to the entire Celtec line, the lower density DigiLite products are designed to be utilized as a high performance, 100 percent recyclable alternative to wood, metal, or other rigid material within the signage industry. “Key benefits of a lighter weight product are potential cost savings due to less material usage and reduced shipping costs. While very versatile, lighter density PVC sheets aren’t recommended for load bearing applications,” he notes.
When comparing high- and low-density rigid board construction, high-density options lend itself to a variety of fabrication processes including digital and screen printing, plus cutting. “It also ensures clean edges after cutting or routing, eliminating the time-consuming step of manual deburring. The substrate’s surface promotes superior ink adhesion, reducing chipping or cracking after cutting that can lead to substrate and ink waste; and ensuring an increased yield of sellable prints,” he offers.
“The density of a substrate shouldn’t affect the overall printability of a substrate when it comes print quality. It could possibly come into play if the weight of the sheet or substrate is too heavy for a printer,” admits Sherrod.
He adds that the density of a PVC sheet will not directly affect its visual appearance. “What would be a factor is the smoothness of a sheet. A smooth sheet will likely give off more of a glossy appearance than a textured surface. A rough or textured surface will produce more of a matte or eggshell finish. What would work better for any given application depends largely on the setting/surrounding area—indoor versus outdoor, dim versus bright lighting.”
Sherrod says Vycom Celtec products deliver consistency in flatness and gauge, resulting in distortion-free printing and effectively eliminating printhead strikes. Quality construction provides for a range of finishing processes including knife and die cutting; Celtec Expanded PVC and Celtec Ultra White sign material can also be thermoformed.
Rigid Rules
Traditional rigid substrates for digital printing are expanding to include lower density options as well as those with added effects.
Nov2021, Digital Output
