What are the different vinyl printing types?
Self-adhesive vinyl printing is a plastic film that is used to cover signs and vehicles. There are many different types of self-adhesive vinyl available for the production of large format graphics. In this blog, we look at the different types, material limitations and the pros and cons of each.
What is Calendared vinyl printing?
‘Calendared’ vinyl is produced by being formed with heat and pressure through rollers; this process is called ‘extrusion. As a result, calendared vinyl is less stable than cast films. The loss of stability of calendared vinyl films is due to the manufacturing process. Being formed by heat and pressure, so have creates a memory of the plastic structure. This memory means that if you try and mould or heat/stretch into a recess over a short period, the vinyl will shrink and try and move back to its original shape (memory).
Different calendared types
Below we look at the two types of calendared vinyl. Monomeric and Polymeric
Monomeric vinyl printing
Monomeric film is an entry-level vinyl, lost cost film and uses plasticisers with short molecule size. The shorter molecule chains make this vinyl less conformable and less stretchy. Over time a monomeric vinyl can become brittle. A monomeric vinyl is suitable for application to flat surfaces only. Monomeric films will not conform to curves. Over time a monomeric vinyl will show signs of shrinking, visible a few days after application. For example, over time, if a blue vinyl is applied to a white panel, a visible white line around the signage panel will be seen. The line is due to the material shrinking.
Monomeric vinyl adhesives
Most commonly, a monomeric adhesive is water-based. Some more expensive monomeric films will use a solvent adhesive. A solvent-based adhesive is a much better option as the glue doesn’t deteriorate over time. Water-based adhesive can cause problems when trying to remove the film at a later date. The water-based glue breaks down over time, and upon removal, a thin film of glue will be left behind. Removing the glue is difficult and time-consuming. The cost saving on the vinyl is outweighed by the time it takes to remove the glue. It’s always better to use higher quality vinyl that is fit for purpose.
The standard external life expectancy of a monomeric vinyl is between 2-4 years.
Monomeric printed vinyl uses
• Ideal for flat panels with a short to mid-term lifespan
• Site boards and corrugated plastic boards
• Small stickers and decals for flat application only
• 2-4 year life span
Polymeric vinyl printing
A polymeric vinyl Features more high-quality plasticisers and large molecule chain. The polymeric film will tackle slight contours and curves, so slightly conformable to shapes. A good polymeric film has over 50% less shrinkage than a monomeric film. If appropriately applied, a good quality polymeric vinyl is more stable than a monomeric vinyl and is less likely to pull back out of recesses over time.
Polymeric vinyl adhesives
Polymeric adhesive is mostly solvent-based. The solvent adhesive means that the glue has a longer life expectancy. In addition, polymeric vinyl is easier to remove than monomeric more due to the solvent adhesive. Therefore, a polymeric vinyl applied to a vehicle will remove with relative ease, even if this is after a few years.
Polymeric vinyl uses
• Ideal for flat panels with a short to mid-term lifespan
• Site boards and corrugated plastic boards
• Small stickers and decals for flat application only
• Life expectancy is between 5-8 years.
Cast vinyl printing
Used mostly on vehicle wraps and where a premium product is essential, cast vinyl is a high-grade product. Cast vinyl is mostly used on vehicle wrapping or where a superior quality, long-lasting product is required
Why is printed cast vinyl so expensive?
Manufactured using high-grade raw materials makes cast film very expensive. As a result, cast vinyl can be upwards of 4 times more expensive than monomeric vinyl. Cast or ‘casting’ refers to the manufacturing process. Cast films are highly stable and conformable and can stretch up to 50% larger than the original size. Cast films are generally softer and more malleable than a calendared vinyl and, in most cases, are up to 50% thinner than a calendared film. In addition, cast vinyl is usually more glossy compared to its calendared underdogs.
How is the cast vinyl made?
The liquified plastic resin is sprayed onto a high-quality silicon coated backing paper. The cast material is then left to settle on the paper and form naturally. When held up to a bright office light, you will notice that a cast has a randomness to the thickness of the film. The inconsistent thickness is due to the natural settling of the plastic mixture. The lack of mechanical or thermal force to create a cast film means that the film has no memory. The result is a film that can cope with deep recesses and should stay in place. Once the vinyl is applied, any vinyl covering recesses should be ‘baked’ or ‘superheated’. The process of baking the vinyl creates the forming of the vinyl. As the plastic was unformed when made by the lack of heat or pressure, the vinyl shouldn’t have any memory. When the vinyl is ‘baked’, the film now has had its memory set. The result means the vinyl should stay in the recess and not pop out over time.
Adhesive: Adhesives used are always solvent-based and of the highest quality.
Polymeric uses & benefits
• Ideal for deep recesses and complex curves
• High gloss appearance
• Vehicle wraps
• For use on items when only quality is important
• Life expectancy is between 8-10+ years.
