Window tinting film has some fairly straightforward benefits to a driver, not the least of which is heat dissipation, but there are many types of tint film on the market, made of different materials and serving a variety of roles. All window tinting films start with… well, the film, which is a polyester material anywhere from 2 to 7 mils thick (which equates to roughly.002 to.007 inches). In many cases, two or more layers of film are bonded together to form a multi-layered barrier against everything from UV exposure to scratches. Manufacturers of window tinting film may also incorporate chemical UV blockers (such as cyclic imino ester), and if the film is to serve only this purpose there are no additional materials required for use in the film.
The materials sandwiched between the mounting adhesive and the scratch resistant hardcoat are where most film types stand apart. The most basic of tint film contains a simple layer of dyed film, which serves to both absorb heat and reduce onlooker visibility. There is normally some impact on cockpit visibility from within the vehicle, however it will be minor. Due to the application of tint films on the interior side of vehicle windows, the heat rejected by the film is partially stored in the glass itself, and external air movement serves to draw most of this built up heat away during normal driving. Dyed film should never be used on the interior of thermal glass, as it will trap a significant amount of heat between the panes where there is no air movement.
Deposition technology involves a more intricate process where the film is drawn through a tank containing certain types of metal ingots, usually nickel-chrome or aluminum. The pressure in the tank is then reduced creating an artificial vacuum, which is then flooded with argon gas and the ingots are heated, causing the metal to emit particles that migrate to the film surface. The density of the metal deposition is controlled by the speed with which the film passes through the chamber. Deposition technology is relatively inexpensive and is commonly used, however it is limited by the types of metals that can be used in the manufacturing process, resulting in a fairly restrictive product line with few options.
Sputtered (Metallized) Films
This process is a bit more complex than that of deposited films. As with deposited film, sputtering is also done in a vacuum chamber, but the metallizing characteristic is achieved at the atomic level. With the use of electromagnetic fields, argon gas (or another type of inert gas) is directed toward the metal. This process causes very small groups of molecules to separate from the metal and uniformly deposit onto the film. Whereas deposited films must use a very limited number of metals due to the nature of that process, sputtering can be done with over 20 different types of metals, making the process far more versatile and results in a much lighter and thinner coating. These metallized films are a bit more expensive to produce than dyed films, putting this category up near the top of the price range for tinting film.
Hybrid films take the best of both worlds from the aforementioned film types, employing both a dyed film layer and a reflective metallized layer to achieve superior results. By combining the reflective properties of the metals with the absorption characteristics of dyed film, less of each material is required, generally resulting in a slightly lighter tint with equal or greater heat rejection than any of the previously mentioned film types on their own, with low reflectivity. This film type shatters the misconception that assumes darker films provide greater heat rejection. In most cases, the darker dyed films are chosen for little other than aesthetic value and greater privacy at a lower price.
Ceramic tint films are a relatively new development in the industry, and are absolutely top-tier. Utilizing neither the dyes nor metals found in other films, ceramic tint films are constructed with nanotechnology, and while surpassing the heat rejection capability of even the best metallic film, have none of the signal interference normally associated with it. In addition, this highly durable film serves to strengthen the glass to which it is applied, practically eliminating the possibility of glass shattering in a collision or other accident. Ceramic films are also highly resistant to fading, cracking, discoloration, bubbling, and many other drawbacks associated with other film types. It does, however, have one drawback – price. Often it is far more expensive than other applications, but if you are looking for the absolute best window tint solution available, ceramic film is certainly the highest quality film on the market.