films start life as solid pellets othat are melted, extruded and drawn
through a series of rollers so stretching and flattenning it ouit to a
uniform thickness. 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 (see below).
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 stabilised 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.
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 alterative to cast. If there is any doubt as to
which film to use, avoid risk and choose cast film.
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. If there is any doubt as to
which film to use, always choose cast for its enduring quality and long
films use special pvc compounds and high quality pigments to create a
film with a high degree of dimensional stability and outdoor
durability. The softness that is inherent in this type of vinyl
makes it perfect for full vehicle wrap use.
European measurement commonly used to display the thickness of a vinyl
film. 1 micron (µ) equals one thousandth of a millimetre,
0.001mm. A typical 75µ
vinyl is therefore thinner than one tenth of a mm.
American measurement commonly used to display the thickness of a vinyl
film and not to be confused with mm. 1 mil (one thousandth of an
inch) equals 25.4µ
or 0.0254mm. A
vinyl could therefore be described a 3 mil.