Window Tinting: From invention to film selection
Invention of window tinting film
The first patent for solar control window film was granted to the Minnesota Mining and Manufacturing company (now 3M) in 1966.
Manufacture of window tinting film
Window tinting is made from a polyester base material and then coated with materials to block heat, light and UV rays.
At first, window film was little more than “coloured” polyester. The “coloured” polyester film was termed a dyed film and provided only limited UV, heat and glare protection.
The breakthrough in window film design came in the form of metalized coatings. Metal, usually aluminium, is super heated in an electric furnace to form a vapour and the aluminium vapour is passed over the polyester film. A very thin layer of metal is "deposited" onto the polyester film. This thin metal coating serves to reflect the heat and reduce the temperature inside the building.
The next step in the evolution of window tinting film happened when NASA decided to send Man into space. Window films made using the aluminum deposition process were not up to the extreme conditions of space and NASA was forced to find a better way to protect the astronauts from the heat of the sun.
NASA turned to a metal coating process discovered 150 years earlier, in 1852. Silver is one of the best heat “reflectors” and can be deposited onto a polyester film by a process called "sputtering". However, the sputtering process was not restricted to silver and multiple layers of different metals can be deposited on the polyester film. This means that different metals can be selected for their unique spectral properties and allow truely "smart" films to be made. Films that will block certain wavelengths in the electromagnetic spectrum while letting other wavelengths to pass through - eg. films "smart" enough to block the heat and let in the light so our home won't feel dark.
A vast choice of window tinting films
The evolution of window tinting films over the past 50 years has created a vast range of window tinting films which offer customers the ability to choose a film to fulfill very specific priorities. Eg A customer may want a film that will block the heat, protect soft furnishings against fading and not spoil a beautiful view of the city at night, another customer may want a low cost solution to heat and glare to make it more comfortable for staff working at a computer near a window facing the the afternoon sun.
This vast choice of films can be bewildering for customers. Tintplus has written a short paper titled "How to choose the "right" film for the job" to help customers avoid some of the more common mistakes.
Window tinting films performance standards
Along with the evolution of a vast range of window tinting films that has been developed over the past 50 years has been an equally vast range of performance claims. Customers became totally confused by not only how much heat the film blocks but also by UV blocked, visible light reflected, visible light transmitted, solar energy absorbed and solar energy reflected and more. The customer confusion about film performance enabled the sharp operators (or crooks) to make untruthful performance claims and charge high prices for lower cost films. For example, the highest heat reduction films are actually the lowest cost.
In the USA, the US Department of Energy funded the Lawrence Berkley Laboratory within the University of California to establish an International Glazing Database (IGDB). The IGDB lists the solar performance data for window glazing and related products like solar control films. To get listed on the IGDB the product suppliers must get their product's performance data independently tested and verified.
Similarly in Australia, products listed in the IGDB may be Windows Energy Rating Scheme (WERS) rated in Australia using different glass and window frame types, so that customers can be confident the information on which they are basing their purchasing decision is correct. Find out about Energy Efficiency Rating and the Mandatory Disclosure Act and how it will affect the sale and purchase of residential and commercial property in Australia