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"One in five Americans will develop skin cancer within their lifetime." - US DEPT. OF HEALTH AND HUMAN SERVICES, CENTERS FOR DISEASE CONTROL AND PREVENTION

"Skin Cancer is the fastest growing cancer in the world." - THE SKIN CANCER FOUNDATION

"Chronic exposure to ultraviolet radiation has been linked to the development of cataracts and age related macular degeneration. And just because you're indoors or in your car does not mean you're fully protected. Ultraviolet light is still transmitted through glass." - DR. DOUGLAS F. LIVA, OPHTHALMOLOGIST, MEMBER, AMERICAN ACADEMY OF OPHTHALMOLOGY

"Excessive, prolonged UV exposure may be linked to the development of eye conditions such as cataracts and age-related macular degeneration." - AMERICAN ACADEMY OF OPHTHALMOLOGY

"Statistics show that American drivers develop skin cancer more frequently on their left side while Australian drivers suffer from cancers of the skin on their right side. " - DR. ALBERT KLIGMAN, M.D., Ph.D., DERMATOLOGIST, (FATHER OF RETIN A)

The facts don't lie. Skin cancer is the most common and rapidly growing form of cancer in the United States, striking one in five Americans. Doctors say you need to go on the defensive "outside " and "inside " to make sure you don't get burned. PHYSICIANS: The ozone layer is deteriorating. One in five Americans will develop skin cancer in their lifetime and, age-related macular-degeneration is becoming a growing concern in this country. So more and more patients are asking their physicians about sun safety and what they can do to help prevent becoming a statistic. As you are well aware, prevention is key when dealing with skin cancer, photoaging and the like. What you may not be aware of is the fact that glass does not block out UVA rays which account for 90% of all UV that reaches Earth.

From a research conducted by well-known automobile corporation, VOLVO, has found that when temperature in the car cabin increases from 21°C to 27°C, the driver will tend to be 50% more easily in making mistake, while 22% decrease in response to emergency. This has shown that improper temperature management in your car cabin can affect your EQ of driving dramatically. Proper tinting with good air-conditioning will improve awareness during driving and effectively prevent accident.

How Do Window Film Are Made ?

All window films start with the film of course, which is always polyester, 2 to 7 mils thick. Quite often, several thin layers of film are bonded together. One side is coated with either a pressure-sensitive or water-activated adhesive. The exposed surface of most films are also treated with a hard, scratch-resistant coating.

To filter out ultra-violet radiation, chemical uv blockers (cyclic imino esters) are incorporated.The film's purpose is to provide only UV protection and shatter resistance, no other materials need to be added.

Types Of Films

There are 6 basic categories of film construction.

Dyed Film

The dye pigments are applied to the polyester film itself or mixed into the laminating adhesive. Dyed films cut glare but do not reduce solar heat coming through the window effectively as these films control heat by absorbing solar energy. Because most films are applied onto the inner surface of windows, it’s easy to imagine that the absorbed heat would disperse indoors after the film is saturated with excessive heat. However, heat stored in the films will be drawn away by external air movement when the vehicle is moving. Dyed films are usually not stable and less durable, they tend to turn purple colour after a few short years.

Metallized Film

Metallic particles like tin, aluminium oxide and silver oxide are deposited on the polyester film, giving it a reflective coating. Metallized films reject heat by reflecting it before it can be transferred in through the glass. Metallized films maybe highly reflective both internally and externally. They also tend to corrode if ferrous oxide is extensively used.

Metallized-sputtered Film

Unlike conventional metal oxide deposition process, advanced sputtering technology has been successfully developed to allow the utilization of titanium as IR reflector. Titanium has excellent absorption characteristic over a wide wavelength range and is widely used in solar observations. In the sputtering process, titanium is scattered uniformly across the film at the atomic level to achieve highest heat rejection property. As titanium is also resistant to corrosion, it prolong the life span of sputtered film against oxidation.

Ceramic Film

Ceramic films are created by the innovation of new technology. Oxides like alumina, zirconia and carbide which are categorised as part of the Ceramic classification are coated onto polyester film. Ceramic film is neither dyed nor metallized film, it works by absorbing solar heat and thus block the heat from penetrating into car's cabin or room. Accumulated heat will however eventually radiate in from the window glass.

Hybrid Film

Solar control films which contain dyed and metallized layers offerings high heat rejection and low reflectivity. The disadvantage of the hybrid film is that the dye will still fade and turn purple in a few short years later.

Multi-layered Film

As it is named, multi-layered films consist many layers of micro-film polyester in order to hold and retain solar heat absorbed effectively.

Mechanism

Tint is created when tinting film is bonded onto a piece of window glass. Tinting film is usually made out of clear polyester film with a very thin and even layer of tinting agents such as dyes and/or metals deposited onto the film.

A common misconception is that window tint is dark, and night-time driving is impossible when a car is tinted. The truth is that there are films of ANY darkness that suits your preferences. Also, unlike sunglasses that do impair your ability to drive at night, tinting film is designed to reduce glare and not impede night-time driving.

Another misconception is that window tint is bonded onto the outer surface of auto glass. Window tint is applied on the inner surface which also protects the film itself from flying debris outside the car.

Once tinting film is applied to a window, the characteristics of how visible light comes into the car changes. Normal auto glass without tint reflects around 5% of visible light (known as VLR%), absorbs another 5% (known as VLA%), and transmits 90% of visible light (known as VLT%) into the car.

Depending on the type and quality of tinting film applied to a window, these percentages change dramatically. Some tint are more reflective, and others absorb more light. The number you will most commonly see is the VLT% (Visible Light Transmittance). VLT% tells you how much visible light is allowed to shine into the car, and also indirectly how dark the tint looks.

Tinting film doesn't just block visible light. It also blocks harmful cancer-causing ultra-violet (UV-A and UV-B) rays as well as infra-red (IR) rays that cause heat to build up in your car; however, how effective a film in blocking these rays depends on the type of film, the manufacturer, and the quality of installation.

Durability

Similar to car, all tinting film eventually break down. When this happens depends on the quality of the film itself, the amount of exposure to sunlight, and the workmanship of the tinter who installed the film.

The worst dyed window film can show signs of color fading in the matter of months under intense sunlight. The average hybrid type film lasts for 5 years, and the best quality metallized sputtered or deposition window film can last for nearly a decade.

Glossary

Film Thickness

Typical solar control window films range from 1 to 2 mil in thickness. For extra protection purpose safety & security films can be many times thicker, such as up to 10 mil.

Useful conversion: 10 mil = 0.01 inch = 0.254 millimetre

Deposition Process

A form of physical vapor deposition (PVD) often used for deposition of metal films. Film is drawn through a tank containing metal ingots where a vacuum is created by reducing the pressure in the tank, which is then flooded with argon gas and the ingots are heated. The heat causes the metal to give up particles that migrate to the film's surface.

Emissivity

The measure of surface's ability to absorb or reflect far-infrared radiation. The lower the emissivity rating, the better the insulating qualities of the window film/glass system.

Infrared Light

A form of electromagnetic radiation with wavelengths between 0. 7 micrometres (0.0007 millimetres) and 1 millimetre. These wavelengths are longer than those of visible light, but shorter than those of microwaves. (The prefix 'infra' means 'below; infrared refers to radiation below the frequency of red light.) Infrared light is primarily thermal radiation, and we can think of this as being heat.

Polyester Film

Polyesters are made from chemical substances found mainly in petroleum and are manufactured in fibers, films, and plastics. Polyester film (PETF) is a semi-crystalline film used in many applications such as videotape, high quality packaging, professional photographic printing, X-ray film, floppy disks, etc.

Reflectance

The amount that is bent or sent back by a medium.

Shading Coefficient

The ratio of solar heat gain passing through window film to the solar heat gain that occurs under the same conditions if the window were made of clear, unshaded double strength window glass. The lower the number, the better solar shading qualities of the window film/glass system.

Solar Absorptance

The percent of incident solar radiation that is absorbed by the window film/glass system. The lower the number, the less solar radiation absorbed.

Solar Heat Gain Coefficient

The ratio of total solar heat passing through a given window product relative to the solar heat incident on the projected window surface at normal solar incidence (I.E. perpendicular to the glazing surface). The lower the coefficient number for a particular window film/glass system, the better it is able to reduce heat.

Solar Reflectance

The percent of incident solar radiation that is reflected by the window film/glass system. The lower the number, the less solar radiation reflected.

Solar Transmittance

The percent of incident solar radiation that is transmitted through the window film/glass system. The lower the number, the less the solar radiation transmitted.

Sputtering Process

A form of physical vapor deposition (PVD) often used for deposition of metal films. Sputtering involves knocking metal atoms off a disc of pure metal with charged, energetic, chemically inactive atoms called ions (from a plasma). The metal atoms will re-deposit and build on top of polyester film.

Total Solar Energy Rejected

The percent of total solar energy (heat) rejected by the window film/glass system. The higher the number, the more total solar energy (heat) rejected.

Transmittance

The amount that is allowed to pass through a medium.

U-Value

The ability for heat to transfer through 1 square foot of window film for each 1° Fahrenheit difference in temperature. It is dependent upon the local climate or environment that the window is located in effects the level of heat transfer and the rate; in summer, heat transfers from the outdoor air to indoor air. In winter, heat transfers from indoor air to outdoor air. The lower the U-Value, the better insulating qualities of the window film/glass system.

Ultraviolet Light

Light having a shorter wavelength and higher energy than visible light. Ultraviolet light is potentially damaging to library, archive and museum objects. Removing UV light can reduce the rate of deterioration. Certain acrylic sheets have UV filtering chemicals built into them.

Ultraviolet Transmittance

The percent of ultraviolet light (UV) that is transmitted by the window film/glass system. The lower the number, the less ultraviolet transmitted.

Visible Light

electromagnetic radiation at wavelengths which the human eye can see. We perceive this radiation as colors ranging from red (longer wavelengths; ~ 700 nanometers) to violet (shorter wavelengths; ~400 nanometers).

Visible Light Absorptance

The percent of total visible light that is absorbed by the window film/glass system. The lower the number the less visible light absorbed.

Visible Light Reflectance

The percent of total visible light that is reflected by the window film/glass system. The lower the number the less visible light reflected.

Visible Light Transmittance

The percent of total visible light that is transmitted through the window film/glass system. The lower the number the less visible light transmitted.