Vinyl film covers the surface of many products, including automobiles, signs and floors. Polyvinyl chloride polymer, known as PVC, is a main ingredient of vinyl. Other ingredients include pigments, solvents, heat stabilizers and substances which improve ultraviolet light absorption. According to Sign Industry, polymeric and monomeric plasticizers add flexibility to the vinyl films. Casting and calendaring production methods produce vinyl films with different properties and uses.
Cast vinyl producers combine ingredients in a specific order and at a set speed to produce a mixture called organosol. The organosol pours onto a moving casting sheet which creates the film’s finish and sends the mixture through a solvent-evaporating process. On production rolls, the remaining solvent-free film receives an adhesive coating. Calendered vinyl begins with the same ingredients as cast vinyl, without the solvents. The ingredients form a dough-like substance which passes through a series of flattening rolls. After it reaches the desired thickness, calendered vinyl receives a gloss or matte finish.
Cast vinyl film is thinner than calendered vinyl film. A casting sheet can hold the quantity of organosol needed to produce a film that is only 2 mm thick. Calendered vinyl is usually between 3 and 10 mm thick because the rollers cannot press the dense mixture into a thinner sheet. Cast vinyl is sometimes called 2 mm vinyl and calendered vinyl is also known as 4 mm vinyl.
Although cast film is thinner, it is more durable and more heat-resistant than calendered vinyl. The casting process creates a thin film without adding stress to the mixture, while the extrusion process stresses the calendered film mixture. After it passes through the rollers, calendered film has a material "memory" which promotes shrinkage at hot temperatures. On the other hand, thick calendered film resists abrasion better than cast film. According to Blueprint Concepts, cast vinyl surfaces last seven to 10 years, while calendered surfaces last up to five years.
Thin, durable cast vinyl film can conform to curved or irregularly shaped surfaces and withstands outdoor temperature changes. Cast vinyl covers automobiles or other products that require a flexible, long-lasting surface. According to Sign Industry, cast vinyl matches and retains color better than calendered vinyl. Calendered vinyl is less expensive than cast vinyl because its production process is faster and it is easier to handle than cast vinyl because it is thicker. Due to its poor heat tolerance and high shrinkage rate, calendered vinyl is suitable for indoor signs, stickers, floors and other products that require frequent resurfacing.
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