Window film

Window film, also called window tint or Lustalux, is transparent plastic film or metallic laminate which is applied to glass windows specifically to reduce heat and radiation from the sun. It is available in many different compositions with varying effects on the optical and mechanical properties of the underlying glass. Because window film is applied to finished glass it is easier to install and less costly than chemically-altered specialty glass.

Primary properties

Heat rejection films are normally applied to the interior of flat glass windows to reduce the amount of infrared, visible light, and ultraviolet (UV) radiation entering windows. Such films are either dyed or metalized (which can be transparent to visible light) to convert incoming solar radiation to infrared radiation, which is then rejected back through the glass to the exterior. They usually cost 10-15 percent more than regular windows but can reduce energy loss by as much as 30-50 percent." [http://www.eere.energy.gov/consumer/your_home/windows_doors_skylights/index.cfm/mytopic=13430 Your Home: Low-emissivity Window Glazing or Glass] ." "A Consumer's Guide to Energy Efficiency and Renewable Energy". United States Department of Energy Energy Efficiency and Renewable Energy.]

To keep the sun's heat out of the house, the Low-E coating should be applied to the outside pane of glazed windows. If the windows are designed to provide heat energy in the winter and keep heat inside the house (typical of cold climates), the Low-E coating should be applied to the inside pane of glazed windows. [http://www.eere.energy.gov/consumer/your_home/windows_doors_skylights/index.cfm/mytopic=13430] Such films also reduce the amount of visible and ultraviolet light entering a window, and are often applied to reduce fading of the contents of a room. Silvered film may also be employed to the same end.

Security films are applied to prevent glass from shattering. Typically applied to commercial glass, these films are made of heavy-gauge plastic and are intended to maintain the integrity of glass when subject to heavy impact. The most robust security films are capable of preventing fragmentation and the production of hazardous glass from forces such as bomb blasts." [http://www.fema.gov/txt/plan/prevent/rms/428/FEMA428_ch6.txt Safe Rooms Within Schools] ." Federal Emergency Management Agency, United States Department of Homeland Security.]

These security films, if applied properly, can also provide protection for vehicles." [http://www.iwfa.com/PreProduction_copy(1)/consumer_info/safety.html Safety/Security Film] ." International Window Film Association.] These security films are often tinted and can be up to 400 micrometers (µm) thick, compared to less than 50 µm for ordinary tint films. If anchored correctly, they can also provide protection for architectural glazing in the event of an explosion. A layer of film (of 100 µm thickness or greater) can prevent the ejection of spall when a projectile impacts on its surface, creating small dagger-like shards of glass that can cause injury.

Graphic design films are generally colored vinyl or frosted. Frosted finish films closely resemble sandblasted or acid-etched glass, while vinyl films are available in a range of colors. Both types of films are commonly used in commercial applications.

Privacy films reduce visibility through the glass. Privacy film for flat-glass commercial and residential applications may be silvered, offering an unimpeded view from the low-light side but virtually no view from the high-light side. It may also be frosted, rendering the window translucent but not transparent. Privacy films for automobiles are available in gradients of darkness, with the darker tints commonly known as "limo tint."

Correctly-applied mirror film can create one-way mirrors.

Other benefits includes protection for passengers in the rear, protection from UV rays (which have some harmful effects), cooling for pets, greater privacy, reduced chance of theft (because valuables are less visible), reduced glare and reflection on liquid crystal display (LCD) screens, and protection for those who have conditions involving photosensitivity or skin sensitivity, such as lupus (SLE). Window film is also considered more effective and practical than stick-on blinds.

Certification and standards

The thicker window films known as safety and security window film are designed to perform under extreme conditions, and as such there are specific standard criteria these films should meet, such as American standards ANSI Z.97, CPSC 16 CFR 1201, Cat II (400 ft-lb), and the British Standards BS 6206 (Class A, B, C). The European Committee for Standardization offer the EN12600 standard Classification of Resistance of Glazing to Impact. Often, building codes dictate that a film must have a report verifying that it has met at least one of these standards.

Solar window film is usually subject to less critical testing. However, standards are in place to maintain a level of quality in the industry. The ANSI Standards ASTM E903 and ASTM D1044-93 relate to the solar/UV transmission properties and abrasion resistance, respectively. The larger window film manufacturers use these standards to guarantee the quality of their raw materials and finished products.

Regulations for automotive use

Automobile window tinting reduces the "visible light transmission" (VLT) through car windows. This can be problematic at night, when motorists must be able to see through the windows of other vehicles in order to spot hazards which would otherwise be obstructed. Police also may want to be able to identify the passengers in a vehicle.

In many jurisdictions, there are laws to ensure darkness of films do not present a danger to motorists:

Tint Limits by U.S. state:

Fact|date=July 2008(Lower number is less light transmittance, thus darker tint)

*In the United States, the Federal Motor Carrier Safety Administration, an administration within the federal Department of Transportation (DOT), specifies a minimum of 70 percent VLT for window tinting on the windshield and the windows to the immediate left and right of the driver for commercial vehicles (the DOT does not regulate private vehicles). The DOT does not specify any VLT requirements for rear windows." [http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.asp?section=393.60 Part 393 (Parts and Accessories Necessary for Safe Operation), Subpart D (Glazing and Window Construction), Section 393.60 (Glazing in specified openings)] ." Federal Motor Carrier Safety Administration Regulations. United States Department of Transportation.] State law may regulate laws for private vehicles and may go further than the requirements those set forth by the DOT; private vehicles may have tint on the windows to the immediate left and right of the driver as dark as 20 percent VLT, depending on the state." [http://www.iwfa.com/PreProduction_copy(1)/consumer_info/auto_statelaws.html Automotive State Window Tinting Rules & Laws Chart] ." International Window Film Association.]
*In Canada, automobile tinting laws are set at the provincial level." [http://www.iwfa.com/iwfa/Consumer_Info/auto_provincelaws.html Canadian Window Tinting Rules & Laws] ." International Window Film Association. 28 April 2003.]
*In the United Kingdom, regulations set forth by the Vehicle and Operator Services Agency under the Road Vehicles (Construction and Use) Regulations 1986 provide that all front windows in front of the B post can have no less than 70 percent VLT. Windscreens are only allowed tinting outside the sweep of the windscreen wipers to a maximum of six inches from the top of the windscreen." [http://www.vosa.gov.uk/vosacorp/repository/Tinted%20Windows%20Nov%202005.pdf Tinted Windows: Your Questions Answered] " (PDF). Vehicle and Operator Services Agency. October 2005.] British police are increasingly cracking down on illegal tinting on vehicles.Rohrer, Finlo. " [http://news.bbc.co.uk/1/hi/magazine/6707873.stm Tinted windows to the soul] ." 31 May 2007 BBC News Magazine.]

Installation

Window films are usually professionally installed; however, most films require few specialized tools to install and may be installed by consumers. Incorrectly installed films may bubble or peel.

It is especially difficult to install tint film on auto glass with curvature, for example, in the case of rear windows of cars, because of the care required in cutting and sizing the film. Auto tint is best installed by professionals; without the proper tools and techniques, amateur filming is prone to bubbling and separation from the glass.

Window film is typically installed after surfaces are thoroughly cleaned and wiped, typically using a commercial cleaner and a scraper blade, and then a simple soap solution is squirted on the glass before the film layer is mounted.Most manufacturers will only warranty their window films when installed by a certified, trained installer.

Removal

Window tint and the adhesive that adheres it to the glass is difficult to remove. While it is generally best done by experts, the consumer can remove it with appropriate materials and care. The process involves heating the film with a hair dryer or a steamer to soften the adhesive, pulling the film off in small sections, and dissolving the glue with a strong ammonia solution which may then be wiped off. Some professional tinting companies remove the glass during tint installation for a perfect finish, making removal of the film very difficult for the novice. As a side note, IGU ( insulated glass units)should not have hair dryers put to them to remove film.

This technique is for the rear window, with the defroster. One way to remove the film is to create humidity inside the vehicle. This is done by using soapy water, a black trash bag, and the sun. 1. Cut open a black leaf trash bag, along the bottom and one side. 2. Lay the bag on the outside of the rear window.3 Trim to the size of the rear window glass.4 Remove to the inside of the car, 5 Spray the inside of the back window with soapy water (water and a few drops of dish soap). 6 Lay the trash bag inside the window, as flat as possible against the glass, also as wet. 7 Shut all doors and make sure the windows are shut. 8 Try to aim the rear window to the sun. 9 Let sit for about 15 minutes, check to see if you can see a difference in the way the adhesive looks. Grab a corner of the film and try to peel it, if this has worked the film will almost fall off. If it is still hard to get off, try again, with the soap. If this doesn't work, take your car to a professional to remove the film.

References