Window film
It is usually made from polyethylene terephthalate (PET), a thermoplastic polymer resin of the polyester family, due to its clarity, tensile strength, dimensional stability, and ability to accept a variety of surface-applied or embedded treatments.
Window films are generically categorized by their construction components (dyed, pigmented, metallized, ceramic, or nano), by their intended use (automotive, marine or architectural), by substrate type (glass or polycarbonate), and/or by their technical performance (privacy, solar control, safety and security).
[1] There are many different grades, shades, colors, and thicknesses of available window films built to offer solutions to a variety of challenges.
Window films are a retrofit upgrade for existing glass that can be used to address problems inherent to glazing, including:[2] Window films are an extremely cost-effective method to reduce heating and cooling costs in existing buildings by reducing the amount of heat transfer through glazing.
[4] Ceramic window films cost slightly more but provide a substantial increase by reflecting and absorbing infrared radiation (IR or radiant heat).
Spectrally selective films act by blocking certain wavelengths of the sun's infrared radiation and reject heat without reducing natural light.
The most robust security films are capable of preventing fragmentation and the production of hazardous glass shards from forces such as bomb blasts.
A layer of film (of 100 μm thickness or greater) can prevent the ejection of spall when a projectile impacts on its surface, which otherwise creates small dagger-like shards of glass that can cause injury.
[7] Window films filter out over 99% of UV rays at 380 nm, reducing the main factor in fading.
However, additional factors such as solar heat, visible light, humidity, and presence or absence of chemical vapors also contribute to fading.
Therefore, the greatest protection from fading is offered by tinted or metallized window films that reject large levels of heat and visible light, in addition to UV.
The chances of glass breakage occurring subsequent to the application of film or sign writing or the hanging of drapes, are very small.
However, breakage can occur and it is impossible to predict the edge condition of the glass without removing it from the frame, an approach that is not practical.
[9] Window films are also used to apply see-through graphics to glass and other transparent surfaces, to provide advertising, branding, signage and decoration.
The larger window film manufacturers use these standards to guarantee the quality of their raw materials and finished products.
The pigment gives the glass a tint, but doesn't provide UV ray protection or heat rejection like most window films do.
