By Cassandra Balentine
Polyvinyl chloride (PVC) media is a staple in wide format printing. More simply referred to as vinyl, it is widely used for its affordability and versatility. PVC is durable, printable by many different ink technologies, and can be coated with a variety of adhesives to produce a great surface for graphic applications. However, vinyl products are not without controversy.
As print buyers and providers strive to make more environmentally driven decisions, vinyl raises some red flags. However, its advantages are clear and manufacturers are working to continually improve vinyl products in response to concerns and demands.
Here, we specifically look at the evolving role of a popular vinyl segment, pressure-sensitive adhesive (PSA) vinyl, which despite some environmental and health concerns is still very much in use within the sign and display industry.
Above: High-performance cast film like 3M Controltac Graphic Film with Comply v3 Adhesive IJ180Cv3 is a popular and common vinyl film used in the graphic arts.
Durable and Versatile
Vinyl has many performance and affordability benefits.
“PSA vinyl remains the best media for cost and printability, and the range of adhesive and film options make it the most versatile for a range of applications,” says Jay Kroll, product manager for cut and craft films, wall and transit media, General Formulations.
The versatility of vinyl lies in the additives—plasticizers, stabilizers, lubricants, and pigments—which can be modified in the manufacturing process to create different levels of desired functional performance. “Vinyl can be made rigid or flexible, making it ideal for graphics applied to flat or curved surfaces. It can also be made in a wider range of thicknesses as compared to alternative media, allowing for it to be used in label applications that will be automatically applied or large outdoor graphics that will be hand installed,” explains Jodi Sawyer, strategic business unit manager – retail, FLEXcon Company, Inc.
It is this wealth of physical and performance characteristics that make PSA vinyl a popular media for a range of application requirements. “While other PSA media may have some of these properties, historically, none have had them all,” she adds. “For example, the advantages of PSA vinyl compared to alternative media such as PSA polyester, polyethylene, and polypropylene are inherent printability without surface treatment, outdoor durability, and conformability.”
The flexible form of PVC is a popular medium in sign and display markets, particularly for PSA products.
This type of media is water and heat resistant, so it can be used indoors and outdoors. “It adheres to almost any substrate and prints beautifully and can be contour cut. PSA vinyl works for endless applications compared to other media,” offers Shaun Jaycox, product specialist, Brand Management Group.
PVC is very durable, can be printed onto with many different ink technologies, and can be coated with a variety of adhesives to produce a great surface for graphic applications. “These can be adhered onto flat, smooth surfaces and conformed to textured surfaces including vehicles. Given this variety of applications, PVC is used for many types of printing purposes,” says Shaun Holdom, global product manager, Drytac.
PSA vinyl is ubiquitous in the industry. “This translates to many choices for products that will run on a variety of printing devices,” notes Wayne Colbath, national sales manager, Continental Grafix USA, Inc. He adds that PSA vinyl is used so often that everyone from the end user and print service provider (PSP) to installer are familiar and comfortable with it.
Available in cast and calendared configurations, “PSA vinyl products offer longer life. There aren’t too many limits on what adhesives can be used, offering a large variety of application options,” shares Michael Aldrich, product manager, FDC Graphic Films, Inc.
Having the print media and adhesive built into a product simplifies selection and inventory, speeds up graphic fabrication, and lowers the cost of production versus printing on a media, then having to laminate an adhesive to the graphic, points out Colbath.
Adhesive-backed vinyl—otherwise known as self-adhesive vinyl (SAV)—eliminates the step of placing a double-sided adhesive on the back of a printed graphic mounting to a substrate. “There is a cost savings associated with this step in consumables and in the production process. SAVs have become a commodity and are reasonably priced compared to ten or even five years ago. Vinyl will withstand environmental changes better than paper graphics,” explains Brian Gibson, wide format graphics specialist, GBC, a division of ACCO Brands.
The impact of vinyl on the environment and its association with health concerns is a big negative and driving force of alternative options.
The base material for SAVs is typically PVC, which according to Gibson is the world’s third most widely produced synthetic plastic polymer after polypropylene and polyethylene. About 40 million tons are produced every year. PVCs are manufactured to be rigid or soft, the latter is popular in graphic arts applications. “To soften PVCs, a plasticizer is used, the most common plasticizer being phthalates. While acceptable in certain products at low levels, Europe and North America have identified phthalates DBP, DEHP, and BBP as reproductive toxicants and prohibits their use in cosmetics and other wearable goods,” says Gibson.
Humans are exposed to phthalates in many ways, including inhalation, ingestion, and—to a lesser degree—absorption through the skin, he adds.
“While PSA vinyl may be fantastic from a functional standpoint, there is much debate about its impact on the environment and safety due to the toxicity of certain vinyl feedstocks, the byproducts of its production, and the many additives required to make it usable,” agrees Sawyer. “Additives can migrate over time. Of particular concern is a group of chemicals in vinyl called phthalates which are often used as plasticizers to make vinyl flexible,” she reiterates.
With all the different chemicals in the phthalate family, Sawyer stresses that making a sweeping statement about the effects of all possible phthalates in all vinyl grades would be ill informed. “However, the perception of consumers—that these chemicals, and PVC in general, are hazardous to the environment and human health—is putting pressure on manufacturers to minimize its use.”
In addition to concerning additives, another negative associated with vinyl and PSA vinyl is its recyclability.
“PVC can be harmful to the environment and humans if it’s not collected and disposed of in the right way. If it is dumped in a landfill, PVC will take literally hundreds of years to degrade, and the plasticizers used to make the product can leach into the ground and contaminate the soil and water,” cautions Holdom.
Due to the many additives in PVC, Sawyer admits it is generally more difficult to recycle post-consumer material back into the supply chain. “This is not to say that PVC cannot be recycled, but there are more barriers to avoiding the landfill. The method used to repurpose or recycle can have an impact on toxicity as PVC is more toxic if burned.”
Kroll points out that adhesive coated materials are excluded from recycling programs, so used vinyl typically ends up in landfills or incinerators.
Every year, more graphics get disposed into landfills. “End users, PSA manufacturers, and print providers are more aware of their impact on the environment than ever before,” asserts Colbath. He says many large end users are looking at or requiring more sustainable solutions for their graphics. “PVC films, a standard in our industry, are particularly scrutinized as they can take quite a long time to decompose in traditional landfills. Ways to combat this include using PSAs made from materials that decompose faster, are manufactured with post-consumer products, or are completely biodegradable.”
While products are produced with different amounts of phthalates and plasticizers, which can be viewed as an improvement on the previous versions, the problem still remains about waste and recycling. “How we use the products is also a big issue. The loop needs to be addressed at all levels—from the manufacturers and printers through to the installers and the end-user customers,” says Holdom.
Kroll agrees, noting that manufacturing methods have improved to where the production of the various materials are less concerning as a whole, but there is a lot of work to do on disposal of the material after the job is printed, installed, and removed. “Vinyl breaks down over time and the present day chemicals used have less negative impact on the environment.”
Although PSA vinyl is known to have a negative impact on the environmental and public health, as we’ve hinted to above, there are differences in ingredients and processes that change the affect.
“Cast and calendered vinyl both start with similar components but have vastly different manufacturing methods, and neither is inherently better than the other. The same goes for adhesives, providing they are formulated and processed responsibly, and any volatile organic compounds from production are neutralized and filtered safely,” says Kroll.
Alan Miller, application engineering manager, 3M Commercial Solutions, says that whether you use a cast or calendared vinyl film for graphic production, the film is primarily made of PVC. “There are different plasticizers, phthalates, and other components affecting flexibility and durability, but it doesn’t change the fact that the film contains PVC.”
“All PVCs are very similar in make up; it is simply the quality of the ingredients that change,” echos Holdom. Monomeric vinyl is a lower grade and uses cheaper raw materials and therefore has a shorter life. Polymeric vinyl uses better quality materials and has a longer life and stability.
He points out that both monomeric and polymeric are calendared vinyls, meaning the PVC is rolled out a bit like pizza dough. “As with dough, after a certain amount of time the vinyl wants to shrink, and this will happen quicker with monomeric vinyl as it is fabricated from cheaper ingredients,” he explains.
On the other hand, cast vinyls use the same type of ingredients but these are all very high quality. “In addition, the mix is poured into a casting tray to produce the material and it a lot more stable. This could be compared to a cake mix where you pour your mixture into a tin and bake in the oven. The material is formed in that tray and doesn’t have a memory and won’t shrink back like a calendared vinyl,” shares Holdom.
“Some films such as polyethylene are primarily resin while vinyl film has more additives mixed in with the resin. Determining the impact of a PSA vinyl product or alternative media on the environment goes beyond the type of film used,” adds Sawyer. To identify the impact, she says it’s necessary to look at the entire product construction—the film, adhesive, and liner. Adhesive types can vary from water-based and solvent-based acrylic adhesives to rubber-based and hybrid acrylic/rubber-based adhesives. “Liners can be silicone coated paper or plastic. Because the combination of raw materials used to make a PSA vinyl product can vary, when evaluating the impact of a product on the environment, it’s important to work with the manufacturer who can provide content and compliance information for the particular PSA solution.”
The Drawbacks of Evolution
While it is apparent that vinyl products must evolve to continue to serve eco- and health-conscious populations, it is important to understand any potential compromise.
“PVC films have been around for awhile, and it takes time and incentives for customers to make the switch to non-PVC films. However, we are starting to see a change in the industry where end users and graphic manufacturers are insisting on using non-PVC films for their projects. As more customers become aware of the environmental concerns regarding PVC, they will investigate other solutions. The great thing with some of the non-PVC options is they are not giving up any product attributes but are actually getting a wider range of attributes with a sustainability edge for a slightly higher cost,” says Miller.
Kroll admits that challenges of availability, cost, and performance are the main concerns with many of the new vinyl alternatives. “Often the ‘green’ alternatives are considered such due to technicalities and spin—they are still polyolefin films that are produced from non-renewable resources. These films often rely on additional coatings to support limited print capabilities, adding more manufacturing overhead and introducing more chemicals to the process and waste stream.”
While phthalate-free vinyl is a much better option for the environment, there are many challenges with these products. “First, they’re not as flexible, they’re rigid and brittle. Second, they’re restricted to more flat or light contour applications, for example, cargo vans, since they don’t have the polymers that PVC vinyl has. Third, they’re limited to around five year outdoor durability. And finally, they can cost more,” notes Aldrich.
“The biggest advantages are using products that are better for the environment, and drawing attention to your company as being green to customers, municipalities, and others where this matters,” says Colbath. The drawbacks are limited choices as the market is emerging, higher cost as the products can be specialized, and learning to work with the new products.
Holdom stresses that while more PVC-free options are coming onto the market, not all are truly green. “They are still by-products of oil—be it polypropylene or polyester. Once again, it’s about using the right products for the right applications and considering the correct adhesive options. Unfortunately for the environment, in terms of value and conformability, PVC is still the best option.”
Sawyer says the biggest advantage is the increased compliance of the materials used to manufacture vinyl films. “Cleaner vinyl means it is moving in a better direction from an environmental impact perspective. Any difference in performance characteristics will depend on the additive being changed. Stabilizer updates may or may not affect durability, where a modification to a plasticizer may or may not change the handle of the film.”
With most of the altercations being made to vinyl film, she doesn’t expect to see a significant difference in performance for printers. “Compliant components should be able to mimic the performance of the non-compliant components. That’s the goal when manufacturers are making changes.”
The Future of PSA Vinyl
While there is a need and demand for PVC alternative vinyl, we’re a long way off from discontinuing the use of these products.
There are pros and cons to PSA vinyl. “Impact goes beyond product content to the method for manufacturing the product and environmental and sustainability management systems in place to reduce carbon footprint and waste, and to increase opportunities for recycle and reuse circularity in the process,” explains Sawyer.
Despite our push for alternatives, Kroll says we have yet to discover anything as versatile as PSA vinyl. “Its cost, performance, and adaptability for different applications will keep PSA vinyl relevant well into the future and it will continue to improve in formulation and sustainability as well,” he concludes.
Despite some health and environmental concerns, PSA vinyl continues to dominate the sign and display industry thanks to its range of physical and performance characteristics.
Jan2022, Digital Output