Everyone in the sign industry knows the term “Cast Vinyl”, but not everyone really understands what it means. This video describes what cast vinyl, or cast film, is and what it means to your sign and graphics business.
What is Cast Film?
In making cast film, we’re taking PVC, plasticizer and different pigments and making them into a paint. Then we actually paint or coat it right onto a substrate, or a mold. We call it “casting” because we paint it right onto a mold. We don’t think of a mold as being 6,000 feet long and 60 inches wide, but it is a mold nonetheless. When we finish casting that film, the face that you would use and print on is actually resting right on that mold. If we wanted to make a carbon fiber cast film we’d cast on a carbon fiber base. In the same way, if we wanted to make a matte film we would cast on a matte base.
The key here is that we made a paint. When making that paint we can use very high molecular weight or large polymers. Polymers are difficult to work with in their raw state, but make a film that is very stable in application.
Once the casting is finished you’ve got a product that has gone through an oven “wet”, slowly dried out and finally brought up to temperatures around 400°f in order to cure; but when you cure materials with that high of energy it usually means it takes a lot of energy to destroy them, and that really ends up being the difference. While calendered film is almost three mils thick, cast film is only two-mils thick and lasts almost twice as long.
When to use Cast Film
We put cast film through almost every application that vinyl film can survive. While calendered film can cover about 70% of those applications, it’s that top 70% that separates the men from the boys. You can see why cast film is a more expensive product to buy. It certainly a more expensive product to make! However, the end user benefits when you are able to take a thin film that is flexible and malleable. This makes it perfect for use in areas such as fenders and car mirrors and in complex applications like thermoforming. Calendered film doesn’t have a prayer at meeting those applications.
The process of manufacturing a thermoformed sign exposes the vinyl to very high heat, over 400°F. At the same time, it stretches vinyl up to 50% while demanding that color stay consistent and that the film lasts more than seven years. Cast film is your only option. Now think about a vehicle wrap. A vehicle wrap is the hardest application for vinyl; the film needs to be durable, conformable and absolutely perfect. It must conform to door jams, deep channels and all those other difficult areas of a vehicle. That is a job that only cast film can do.