General Description
The efficiencies of solar control window films are closely related to local weather conditions, building orientation, window size, and other factors such as exterior shading conditions.
Solar control films also can help provide an element of appearance uniformity for large commercial buildings, residential high-rise apartments or condominiums.


Product Benefits
All types and varieties of window film exhibit three important primary product features:
. Solar heat control
· Ultraviolet radiation control
· Improved protection from shattering glass.

Solar Heat Control
This feature provides the following basic consumer benefits:
a. Improves energy cooling efficiencies
b. Reduces energy consumption and utility costs
c. Improves living comfort and working conditions
d. Balances hot/cold spots in buildings

Product Benefits
Solar control films contain ultraviolet absorbers, which reduce the amount of ultraviolet radiation being transmitted through glass doors or windows.

Improved Protection from Shattering Glass
Both solar control and safety film provide protection against the effects of glass breakage, helping to prevent glass that has been shattered from flying dangerously through the air causing personal injury or property damage.

Light and Glare Reduction
This product feature offers several related consumer benefits:
· Reduced glare
· Increased level of privacy
· Improved comfort and working conditions
· Improved visual appearance for window display merchandise
· Reduces the amount of visible light being transmitted through glass





Basic Window Film Manufacturing Principles
Window film is manufactured through a "converting" process. This film manufacturer converts several already existing products into a new product form.

Raw Materials Content
• Polyester Film

Polyester film is durable, tough, and highly flexible, absorbs little moisture, and has both high and low temperature resistances. Safety film usually features one or more layers of polyester film laminated together to form a tough and durable product.


Adhesives
Window film manufacturers utilized a variety of patented adhesive formulations to apply their films to the glass and to laminate one or more layers of polyester film together.

• Mounting Adhesives
Adhesives used to apply window film to the surface of glass fall into three main categories:
Pressure Sensitive Adhesives (a.k.a. PS)
· Detackified PS Adhesives (a.k.a. DPS)
· Water Activated Adhesives (a.k.a. Dry Adhesives)

Films utilizing all types of adhesive are installed in similar fashion, a soapy water or proprietary mounting solution is sprayed on both the glass surface and the film adhesive surface after the protective liner has been removed. The film is then positioned on the glass, cut to size, and squeegeed to remove excess water.

The main difference between pressure sensitive and dry types of adhesives is how they bond with the surface of the glass. PS Adhesives for a "flat" mechanical bond with the surface of the glass based on pressure between film and glass.

Regular PS versus DPS
PS and DPS Adhesive systems use the same adhesive formulation. When the silicone release liner is removed from regular PS, it exposes a relatively soft and tacky surface.
The DPS adhesive system has a protective gel coating that covers the Pressure Sensitive Adhesives. When the liner is removed its adhesive surface is not sticky, or as is called in the trade "detackified

The Difference between Solar and Safety Film Adhesives
The basic difference between safety film and solar control film, when it comes to adhesives, is as follows. The solar control adhesive system is designed to ensure that the solar control window film remains adhered to the existing glass window. Traditionally, solar control window films use PS, DPS, or Dry Adhesive Systems.
However, safety films are designed in such a manner that in the event of glass breakage, the glass itself remains adhered to the film substrate.

Laminating Adhesives
Laminating adhesives are typically used to bond two or more layers of film together. These layers may in turn be laminated to form a final product.

Ultraviolet UV Absorbers
Special ultraviolet UV absorbers are utilized to prevent the sun's ultraviolet rays from breaking down the polyester film or adhesives that laminate the layers of polyester film together.


Scratch Resistant Coating (SRC)
Manufacturers utilize numerous types of scratch resistant coatings applied to the exterior surface of the film to protect it from normal wear, tear, and abuse by humans or by the natural environment.

Release Liners
The mounting adhesive of window films is protected by either silicone or non-silicone coated release liners. The liners are removed in the installation process.



Basic Window Film Types and Structures
There are three categories of window films:
1. Clear (Non-Reflective)
2. Dyed (Non-Reflective)
3. Vacuum Coated (Reflective)
a. Metallized
b. Sputtered

Clear Film
Most clear film products fall into the category of Safety Films. These films offer safety protection and UV control to reduce fading.

Dyed Film
These films contain no metals and are considered non-reflective. They provide glare and fade control, and reduce heat gain by solar absorption. As these films do not contain metal, they are not very effective in terms of solar control.



Vacuum Coated Film
These films have tremendous solar control properties because they can reflect significant amounts of solar radiation. There are two basic manufacturing processes for metallized types of films:
1. Metallizing
2. Sputtering

Both processes are known as vacuum coating in the window film industry.

Metallizing
In simplest terms, metallizing (or vacuum coating) is a process whereby a metal (almost exclusively aluminum) is applied as a layer (coating) onto a clear polyester film, to which another layer of polyester film is laminated. These products are excellent solar control films capable of rejecting over 80% of all solar radiation.



Sputtered Films
The basic sputtering process involves a large vacuum chamber and an inert (or reactive) gas atmosphere as well as electrical energy.
There are two types of sputtered films:

· Films featuring a metal or metal alloy, e.g. stainless steel, nickel-chromium, etc.
· Films featuring a metal oxide.

Sputtered films have excellent solar heat control properties like those that are produced by the metallizing process.

Window Film Comparison
Films with roughly equivalent visible tight transmissions (VLT) will have similar solar control performance, depend on the individual constructions of the products. In some cases, films with the higher VLT may have a greater solar control benefit than products with a lower VLT.
The most efficient solar control films are vacuumed metallized films that have a low visible light transmission in the 15 to 20 percent range, and a high heat rejection factor in the 70 to 80 percent region.

• Manufacturer Warranties
Warranties for film cover most potential defects such as demetallizacion, peeling, bubbling, delaminating, and color change.

• Planning for the Installation
Neither window cleaning nor film installation should be done at night because both require plenty of natural light for careful inspection of and proper cleaning of the glass surface. Working shaded windows keeps the installer more comfortable and, because films dries more slowly, gives more time to maneuver the film and fix mistakes.

Decals and Stickers on Glass
Many windows have stickers, decals, burglar tape, and other such items on the glass. If they are not highly raised above the glass, film can be applied over them (with a poorer bond on the decal than on the glass). Burglar tape and alarm contacts are also found on windows. Film can be installed over such an irregular surface. Alarm contacts, however, must be removed before applying film, but should not be done by the installer.

Installation Instructions
Window films can typically be divided into 12 steps:
• Step 1 Film Inspection
Inspect all boxed of film before leaving for the installation site for the following reasons:
a. That the correct film as specified on the purchase order for that customer is in the proper box.
b. That the correct size of film for that customer's windows will be taken to the installation site to minimize waste.
c. That the adequate quantity of film is on the rolls to complete the application, thus reducing unnecessary travel time.

• Step 2 Window Preparation
a. Contact the customer to confirm with the proper person who will provide access to the installation site.
b. Each window must be prepared for installation.
1. The customer should always be responsible for providing clear access to the windows: moving all blocking furniture and removing drapes, blinds, shades, or any other window treatment that would limit access to the window.
2. Cover the floor or carpet with a clean canvas tarp. Do not use plastic tarps, as water might remain in puddles on the plastic. The canvas tarp protects the carpet from the water.
3. Cover ventilation ducts that are in close proximity to the window to minimize dirt from the moving air, and to help equalize the temperature of the glass.

• Step 3 Clean Glass and Frame
a. With a damp cloth and mild liquid detergent wipe down all of the window frames, including the sashes, stops, jambs, and casing to minimize the change for dirt.
b. While the window is still wet, razor scrapes the entire window to remove foreign particles that are adhered to the glass. Keep the window wet to lubricate the scraper blade to prevent scratching of the glass.
c. Wash the window with the manufacturer's recommended cleaning solution.
d. Re-spray the window and squeegee dry. Wipe down the window frame with a dry lint-free cloth or paper towels.

• Step 4 Cut the Film from the Roll/Dispenser
a. Re-measure the window. Cut the film 2" larger than the vertical dimension. Use of a dispenser in some cases will allow precutting the film so that only two film edges need to be trimmed.
b. Carefully full the film evenly from the dispenser or box, cutting the film to the set horizontal dimension. Pull the film to a length 2" longer than the vertical dimension of the window. Cut the film.

• Step 5 Remove Release Liner
a. If working alone, wet the window and adhere the non-adhesive side of the film against the window. Before doing this, spray the "back" of the film that is going to be placed on the window to ensure that any dust or particles that may be adhered are washed off.
b. Separate the liner starting at the left hand corner. As the liner is being removed, wet the adhesive side of the film thoroughly with mounting solution from a plastic or stainless steel pressure sprayer. Start at the top and wet the entire film to the bottom as the liner is removed.
c. The "Reverse Roll or California Method" can also be used. This method removes the release liner as the film is being pulled from its box.

• Step 6 Adhere Film to Glass
a. Keeping both the film adhesive and glass surface wet adhere the film adhesive side to the glass. Position the left and right top corners leaving a 1/16" to 1/8" border. This will overlap the right and bottom edge by 1" of film for trimming, or overlap entire window and trim all four sides to 1/8".
b. In some cases (hot glass) it will be necessary to add more soap or mounting solution to the water to facilitate positioning of the film on the glass. It is not recommended to apply film to hot windows.

• Step 7 Squeegee Film
a. Spray the non-adhesive side of the film.
b. Squeegee Technique.
1. Set the top of the film by squeegeeing horizontally across the top of the film.
2. For the edges that will be trimmed, squeegee up to 1" away from that edge.
3. Starting in the center of the film, squeegee down vertically one third of the way down the film. Then squeegee horizontally out from the center, pushing the water out from under the edge of the film.
4. Then repeat the above step for the next one third of the film and finish with the last one third of the film.
5. Always squeegee in a vertical direction.
6. After trimming edges (see Step 8) to proper border width, squeegee the film a second time following squeegee technique steps 1-5 from above.

• Step 8 Trimming Edges
a. Trim the edges of the film starting with the upper right hand corner. The use of a trim guide that is 1/16" to 1/8" thick will automatically produce the required border. Hold the trimming knife to the inside of the trim guide and with smooth motion cut down vertically with the trimming knife moving the trim guide and trimming knife together.
b. The 1/16" to 1/8" border is necessary to allow for water removal during squeegeeing and to prevent edge corrosion from moisture.

• Step 9 Splices
a. When the width and length of the window is greater than the width of the film, it will be necessary to splice the film. Two types of splice techniques are available.
1. Butt splice: Math factory edges of the film. Butt the two edges of the film together. Slowly squeegee parallel to the butt-splice.
2. Overlap Cut Splice: Overlap the second panel of film over the first about one inch. With a sharp trimming knife and a straight edge, cut through the exact center of the overlap section. Remove the small cut piece form the top, then lift the corner of the bottom panel, spraying water under the film, and remove the small cut piece of film.

• Step 10 Dry Edges
a. Wrap the squeegee or the trim guide in soft clean lint free colth. Bump all edges of the film to absorb the excess water.
b. The use of certain paper towels is not recommended because they may scratch the film.

• Step 11 Installation Time and Temperature
a. If possible, schedule film application timing to keep installer from working in the direct sun. The hot sun and hot glass will fatigue the installers and may cause handling or positioning problems with the film.
b. It is not recommended that film be installed when the outside air temperature is less than 30° F. Cold air temperatures could possibly cause mounting solution to freeze on the glass damaging the film.

• Step 12 Important Details of Installation
a. In all cases, provide the customer appropriate cleaning and maintenance instructions.
b. On completion of the job where possible inspect the entire job with the customer.
c. Explain to the customer that the film still has to dry and that it's appearance will improve dramatically as the film dries out.
d. Provide the estimated drying time to the customer. The actual time may vary considerably depending on the film type, thickness and numerous other factors.

Miscellaneous Window Film Information and Tips
• Window Cleaning Tips
1. A scratch resistant coating on the outside surface of the film is used to protect it from damage.
2. Use any normal household glass cleaning solutions, or plain soapy water.
3. Do not use any solutions that contains abrasive material, baking soda, Comet, etc. Be careful not to use sharp instruments that could cut or gouge the film.
4. Use soft clean lint-free towels or synthetic sponges to apply cleaning solutions.
5. Use soft cloth or rubber squeegee for drying the glass.

• Indoor Plants
The application of window film will not have any adverse affect on the growth of most indoor plants. Is recommended that owners move the plants (as a test) to another part of the room to simulate a less lighted area before film is applied to judge what the potential affects might be.

• Exterior Window Films
On occasion it may be necessary to apply window film to the exterior of a window. It may be difficult to reach the interior of the window due to fixtures, fittings or other items that are so close to the window.
Many window film manufacturers make a few products for exterior applicatons. These products generally have limited warranties for shorter periods of time. There are also films designed to be installed on the exterior of windows that have been specifically produced as a protection against graffiti on the glass itself.

• Application of Film to Plastics
Window film should not be applied to acrylic or polycarbonate windows, unless it is specifically designed for that purpose.

Window Film Applications for Different Types of Glass
• Wired Glass
Solar control window film should not be applied to the interior surface of wired glass. If it is necessary to install, the film should be applied to the exterior surface of the glass, using exterior window film.

• Tinted Glass
Tinted glass is a major absorber of heat, if the combiner absorption of the window film and tinted glass is very high, this can result in the glass cracking as a result of thermal stress.

• Patterned or Textured Glass
Patterned or textured surfaces will not allow window film adhesive to form an adequate or appropriately strong bong to the glass surface. In most cases, this type of glass is installed with the smooth side facing the exterior of the building; in this case, the window film can be installed on that surface.

• Glass Thickness
It should be noted that the thickness of glass does increase its absorption, and subsequently must add stresses. Extreme pressure required to squeegee the moisture may result in breaking the glass.

• New Construction
Window film should generally be installed in new or renovated buildings only when all other work has been concluded.

• Skylights and Window Film
The application of window film to skylights is much more restricted versus vertical glazing systems. If the film is installed on the outside surface of the skylight, it may have a shorter live span, because most skylights accumulate moisture as the result of rain, snow or humidity. Many manufacturers recommend edge sealants for exterior applications.