Given the various amazing protective properties offered by window film, you might be tempted to think that it is a space-age material. If so, then you would be correct, because glass film technology was initially developed by NASA, which was seeking reflective technology solutions to protect spacecraft windows from the extreme temperatures found in space.
It didn’t take long for commercial ventures to realize that reflective technology in glass film had the potential for earth-based applications, and in 1966 the 3M™ Company patented the first window film for commercial building applications. Since then, glass film technology has significantly expanded, giving the material properties that can enhance glass safety, UV ray blockage, glare reduction, night vision, and so much more. Glass and window film technology continues to advance, with recent evolutions including a film that can cloak digital screens from prying eyes by selectively filtering light oscillations—a technology known as “privacy in plain sight.”
We here at ClimatePro wish we could lay claim to helping develop this technology, but that might be a stretch, despite what some of our more creative technicians might think. However, with 40 years of coming up with window tinting solutions for businesses and homeowners in the San Francisco Bay Area, we can lay claim to helping expand the use and application of window film. And our extensive experience gives us expertise in all things about window film.
Which begs the question, what do you want to know about window film?
Well, let’s start with the basics: what exactly is window film and how is it made?
What is window film?
Window film, also known as “window tint” and “glass film,” is a thin laminate film that can be applied to most glass (and other) surfaces to change various properties, such as transparency, resilience, UV ray absorption, insulation, and reflectivity, to name a few. Window film is typically used either solely or (more commonly) in combination for the following purposes:
- UV Protection
- Heat and Glare Reduction
- Thermal Insulation
- Sun Fade Inhibitor
- Safety (breakage and shatter resistance)
- Night Vision Enhancement
- Graffiti Protection
Primarily applied to windows on homes, commercial businesses, and vehicles, window films may be categorized and marketed under different parameters, such as by material composition (dyes, metals, ceramics, etc.), intended application (home, business, automobile, etc.), or primary property value (safety, UV protection, heat reduction, etc.). No matter how it is categorized or marketed, though, all films are manufactured under a similar process.
The Production Process
While specific window film manufacturers may have their own proprietary methodologies for producing window films, the overall process is similar for each. And it typically starts with rolled sheets of thermoplastic polymer resin, or similar plastic formulations, that come in a variety of widths and thicknesses to serve the wide range of film production needs.
When considering the film manufacturing process, picture the processing of the rolled sheets of plastic similar to how newsprint is rolled through the printing process to produce newspapers. Instead of ink, though, the plastic sheeting is coated with additives, adhesives, curing agents, and other chemicals as it rolls through processing, with the combination of materials depending upon the desired window film type. Additionally, while newsprint only requires the application of pressed ink, the materials applied to the plastic sheeting to make film often need other treatments, such as heat curing or vacuum application, to successfully produce the finished product.
As the rolled sheets of plastic unwind, the first step, or application, involves what is known as “advanced sputtering,” in which an ultra-thin, transparent layer of primary additive is applied to the plastic sheeting as it starts its roll down the processing line. This primary additive is the main component used to achieve desired film properties and can include dyes, metals, ceramics, nano-particles, and other materials or combination of materials. Depending upon the desired film properties, sputtering may be subject to conditions like heat or UV light that cause a reaction to the additive upon or shortly after its application, in order to achieve unique characteristics.
Depending upon the additive and desired properties, manufacturers might use a process known as vapor deposition or E-beam to apply the additive to the plastic sheeting. These processes take place in a vacuum chamber and rely on heat to evaporate the additive, which then adheres and solidifies onto the plastic sheeting.
The next step involves melding the additive-covered plastic with laminating chemicals, and additional dyes, if needed. This is followed by the application of a layer of adhesives and scratch-resistant hardening chemicals, creating additional layers on the plastic sheeting. In some cases, additional treatment—such as heat or UV curing—may be needed to influence particular properties in the film.
Some films are produced by layering the additive material(s), property inducing chemicals, and adhesives between two sheets of plastic, which are joined together under high pressure and heat. Exterior surfaces are then coated with an additional film layer of laminate and hardeners, and one side may receive a coating of adhesive for its application to the glass.
After laminating and hardening, the newly formulated film is precision cut to desired widths and lengths and re-rolled for shipping. Manufacturers typically subject the window film to intensive inspection and testing throughout the entire process, to ensure a defect-free final product.
Solar Gard. “How Our Window Film is Made.” November 7, 2016. Solar Gard. Retrieved at: https://www.youtube.com/watch?v=jlDTZqi0-B8
“Myths About Window Film.” Date Unknown. Convenience Group Inc. Retrieved at: https://www.conveniencegroup.com/myths-about-window-film
“How Its (sic) Made Window Film.” March 9, 2015. How Its (sic) Made. Retrieved from: https://www.youtube.com/watch?v=jKW8T4xmzqg
“Window Film Industry and How Film it’s (sic) Made.” Date Unknown. Tint Depot. Retrieved from: https://tintdepot.com/tint-depot-tinting-school/window-film-industry/
“Window Film.” No Date. Wikipedia. Retrieved at: https://en.wikipedia.org/wiki/Window_film