In any application, labour inevitably accounts for the bulk of your production costs. This makes choosing the right materials vital. By selecting the best possible materials for the job, you can improve quality, enhance productivity and minimise wastage whilst maximizing your profitability. Here is an introduction to the different types of products to help you make your selection.
At first sight, there is little to distinguish between the three types of vinyl available today: cast, polymeric calendered and monomeric calendered films. However, the difference between them is obvious after they have been applied for any length of time. The film that looks as good as the day it was applied is manufactured using a process known as casting and is described as a cast film.
A cast film is a premium grade vinyl that starts life as a liquid, which is then allowed to spread out to an extremely thin layer. Cast films have no memory and are stable, so shrinkage is barely perceptible. Because cast films are thinner and softer, they are easier to cut, weed and apply. Cast films conform over substrate irregularities such as rivets and textures, making them the preferred option for the most extreme exterior applications – especially vehicle wraps. Cast films are also often used for interior or less challenging applications when special or PANTONE® colours are required.
- Long term solution
- Highly conformable
- More dimensionally stable and resistant to shrinkage
- Highly resistant to fading
- Highly resistant to chemicals
Calendered films start life as a lump of plastic that is then flattened by being passed through two pressure rollers. Though not as high quality as cast films in demanding applications, film produced by this process can nevertheless be adequate in less demanding conditions. Calendered films come in two types: polymeric and monomeric.
- Polymeric calendered films
Polymeric calendered films have added polymers to reduce shrinkage. However, although they have developed significantly over the years, they still fall short of the stability and durability of cast films. Polymeric films fare much better in exterior applications than monomeric films but are not suitable for application over surface irregularities such as rivets and corrugations. For less demanding exterior work, polymeric films offer a workable alternative to cast. If there is any doubt as to which film to use, however, avoid risk and choose cast film.
- Monomeric calendered films
The least expensive vinyl film is monomeric calendered. These films are not suitable for demanding exterior applications such as vehicle liveries or fascia signs. The face film of monomeric film is not stabilized so it will almost certainly shrink to reveal the adhesive beneath. Dirt will adhere to this revealed adhesive and will be clearly visible as a sticky, black outline around the lettering and other elements. The sticky black outline is usually only the start of more severe degradation to come. Eventually, the vinyl face film will begin to curl up and flake off like peeling paint. Monomeric films, therefore, are best suited to short-term exterior applications and interior work.
In addition to the three basic types of vinyl film described above, the following films are also available.
- Polyester films usually have a very high gloss finish. They do not stretch so are suitable only for application to flat surfaces.
- PVF films are chemically inert to the solvents found in stains and paint and are typically used as a protective measure where graffiti is likely.
- Scrimmed PVC films are used for banners and stretched sign faces because of their enhanced strength. The scrim can be black to prevent “show-through” on double-sided banners.
- Brittle cast films, as the name suggests, are brittle in make up and very difficult to remove. This makes them ideal for security labelling.
- Hybrid films are typically a combination or construction of two or more materials. Introducing the characteristics of two material types makes it possible, for example, to print on a material with an otherwise non-receptive print surface.
As with all product choices, understanding the broad types of materials will help you make adequate selections but if in doubt, you can always contact Spandex and speak with one of our experts whose job is to guide you to purchase the right products for every application.