Think cast vinyl is a must for this project? Think again

With a myriad of supply chain issues, some materials are more difficult to obtain than others. One such material is cast vinyl. However, for some applications calendered vinyl – which is more readily available and more cost effective – can replace cast. This article, sponsored by FLEXcon and written by Jodi Sawyer of FLEXcon, identifies where calendered vinyl is an acceptable substitute.

By Jodi Sawyer, FLEXcon

Train wrap produced with FLEXcon calendered vinyl.

While it’s not news that there are myriad supply chain issues in the industry, it’s worth noting why some raw materials are more scarce than others. One such material is cast vinyl. Part of the reason for its low supply is that the same resins used to create it are also used to create adhesives, and priority is given to crafting adhesives. This, of course, creates a challenge for print service providers (PSPs) who rely on cast vinyl for the large format graphics and packaging they produce. The good news is that for some applications calendered vinyl, which is more readily available and more cost effective, can replace cast and still provide the required performance without being over-engineered. The purpose of this article is to raise awareness of when calendered vinyl is an acceptable substitute and why.

There is no need to use more expensive cast vinyl on flat interior surfaces that will not be exposed to harsh conditions.

Cast vinyl is known for its five to seven year outdoor durability and conformability, making it ideal for exterior applications that will be exposed to UV rays and weather, as well as vehicle wraps that require the ability to conform the graphics around tight. compound rays and curves. It is also possible to have cast vinyl produced in custom colors, which is appealing to brands where a brand color match is critical to brand recognition. Calendered vinyl typically has an exterior durability of two years and an interior durability of up to five years. Although less conformable than cast, it works for short-term changing applications on simple flat and curved surfaces and can be used on complex surfaces with installation techniques that take into account the differences in behavior between the cast and calendered vinyl. Since calendered vinyl is less expensive, there are total savings applied for its use in certain applications.

What is the difference?

Cast vinyl is made from liquid resin which is cast onto a casting sheet. The process gives it dimensional stability in all directions while making it thin and flexible enough to conform to application requirements. It can also resist heat during installation, allowing installers to use heat guns to help it conform better to rough textured surfaces or around complex surfaces such as door handles and rivets to achieve a painted look.

Calendered vinyl starts out like taffy and passes through gigantic heated rollers that stretch it machine-wise into thin sheets. The result is a thicker, less flexible film that works well for flat to moderately curved surfaces. The application of heat, however, may cause a color change and produce a stronger bond to the application surface than desired.

The differences in thickness and conformability mean that the two films behave quite differently. The molding is rather flimsy and the flexible handle is what allows it to conform to complex surfaces. These attributes along with its dimensional stability allow cast vinyl to tolerate high temperatures such as summer weather in hot climates and south-facing surfaces with dark graphics. Calendered film is less flexible than cast and dimensionally stable in the machine direction only. If installed over rough textured surfaces such as a textured wall, a heavier adhesive coat weight may be required as the film will not conform to the surface topography as a cast product would. It offers better abrasion resistance than cast iron.

Key Attributes to Consider

PSPs looking to switch to calendered vinyl for certain applications should ask themselves these questions:

  • Will the graphic be installed indoors or outdoors?
  • Will the placement be vertical or horizontal?
  • In which geographic region will the graph be installed? UV exposure in Chicago is different than in Phoenix.
  • What is the duration of the application?
  • Are there any compound or tight radius curves that need to be covered?
  • Is a custom color film required or can the desired color be achieved through the printing process?

For example, a graphic placed on top of a canoe – a flat, horizontal surface – might look ideal for calendered vinyl. In New England this might be true, but in the Southwest it might not be, given the difference in UV exposure and duration. In this case, based on its long-term outdoor durability, cast vinyl would be the best choice. On the other hand, an interior wall or floor graphic, which would not be exposed to UV or other environmental conditions such as extreme heat, humidity or chemicals, would be a prime candidate for a vinyl. calendered versus long-term outdoor application. applied to compound curved surfaces. This is not to say that a calendered vinyl can never be used for a typical cast vinyl application. The Operation North Pole train graphics, a short term application for which FLEXcon has donated materials on several occasions, were printed on calendered vinyl. The key in a situation like this is to work with an experienced installer who understands the limitations of calendered vinyl – where to make relief cuts etc. – so that the material can do the job.

An experienced installer can help ensure successful installation of calendered vinyl over complex surfaces.

Rethink product selection

While cast vinyl may be the only reliable choice for some applications, there are many where calendered vinyl could be substituted without risk to the success of the application. Yet print shop customers quite often specify cast vinyl for applications that don’t require its levels of durability and flexibility. Why? Because that’s what they know works for their outdoor applications, and “if it ain’t broke, don’t fix it”. PSPs also have a certain level of comfort working with molding, and while they may be able to offer a more economical calendered vinyl in some cases, why take on the risk associated with a substitute rather than just going for it? stick to specs? However, current supply problems could force their hand. In fact, the demand for cast and calendered vinyl has increased and is expected to continue. According Grand View Search, the global vinyl wrap market reached US$3.23 billion in 2021 and is expected to reach US$4.42 billion by 2028. This growth is attributed to the growing demand for fleet vehicle graphics and the the rise of the signage and graphics industry. If supply chain issues persist, PSPs may need to reserve their cast vinyl supplies for applications that really need it and offer calendered vinyl for short-term changeable applications that don’t need it. Knowing when it is appropriate to make a substitution and how it will affect installation and performance will be critical to securing the business and ensuring customer satisfaction. When the choice is unclear, consulting the manufacturer may be the best choice.

For more information, visit FLEXcon online.

Jack L. Goldstein