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Common questions about Security Window Film

By December 2, 2014Uncategorized

Here are a few answers to some of the most common questions about

Security Window Film. Enjoy!

Question: How Does Security Window Film work?

Answer: Security Window Film, which is available in a variety of thicknesses and tints, is generally installed on the interior side of the glass, though specialized exterior films are available. In the event of an impact or explosion, the film serves to reduce the likelihood of glass breakage, but where shattering does occur the film firmly holds the pieces of glass safely in place. The films have an exceptionally strong, energy-absorbing mounting adhesive, and are composed of polyester film layers that are extremely high in tensile-strength and break-strength.

Question: Is it BULLETPROOF?

Answer: NO, not to any measurable standard anyway.  There are many reported instances where glass windows protected with security film have stopped bullets.  There are even some dealers purportedly showing videos of specially prepared windows stopping bullets, albeit with their security film applied to ½ inch laminated glass which is not commonly used in schools or commercial applications.  However, the ballistic variables are too numerous to allow generalizations.  The size, shape, mass, velocity, and trajectory of the bullet as well as the composition and type of glass on which the film is installed make it impossible to make any precise, warrantable claims.  Generally, smaller caliber bullets can be, in some circumstances, deflected, slowed, or occasionally stopped altogether.  But no reputable film company in the industry is justified in making warranted statements about their films being “bullet-proof” or even “bullet-resistant”.  Until such time as fully defined criteria and controlled tests are in place that are nationally or internationally recognized, and comprehensive product testing is actually performed by reputable testing organizations, there will be no bullet resistant window film.

Here is the official position from the International Window Film Association on Bullet Resistant Window Film:


The International Window Film Association (IWFA) has the utmost concern about any written specification or recommendation that would call for the use of any type of window film, such as a safety or security film, as a primary component of a “bullet-resistant glazing”. Safety/security films are being used in conjunction with various designed and tested bullet resistance glazings, but primarily as a “spall shield” to reduce the “spalling” off of small fragments of the glazings on the interior side in the event of being penetrated by ballistics.

Our industry believes there are adequate and acceptable standards and methods for testing of products as protection against ballistics. Since window films are an addition to a glazing and not intended for use as the glazing itself, we firmly believe that an individual glazing should be tested both with and without film installed on it for any comparison of improvement in total performance. In some cases, we have seen demonstrations or claims that the use of film imparted some bullet resistant value when, in fact, the glazing itself without film had almost those same bullet resistant qualities. Extreme caution should be taken, however, to make sure that any claims about performance due to the addition of a film layer clearly state the specifics of the glazing itself as supplied by the glazing manufacturer, the specifics of the film itself as supplied by the film manufacturer, and all relevant specifics of the ballistics used and the conditions of the test. Any attempt to imply performance due to the application of the film under any other conditions (different manufacturer, different glazing, different ballistics, different conditions), we believe, would be irresponsible as the margin for error could be one of life safety.

Darrell Smith
Executive Director, IWFA
(276) 666-4932

Question:  What is Security Window Film made of?

Answer: Security Window Film is made of Polyethylene Terephthalate (PET).  PET film is very optically clear and largely unaffected by heat or moisture.  PET used in the manufacture of window film is a bi-axially oriented crystalline form of PET.  The crystallinity of the PET is why the film retains its optical clarity, as opposed to the PET used in the manufacture of a water bottle, which is amorphous (having no crystalline structure), causing distortions when you look through it.

  • Some decorative window films that do not require great optical clarity use Polyvinyl Chloride (PVC) as the formulation will enable the manufacturer to import textures, patterns or colors to the film.  Security window film is not made of PVC.
  • Polyvinyl Buteral (PVB) is used in the glass industry as the inner layer of laminated glass.  PVB is generally quite thick when compared to window films (up to 30 times thicker) and it is significantly viscous and puncture resistant.  However, PVB can become brittle during extremely cold weather, weakening the structural strength of the laminated glass.
  • Security Window Film is typically manufactured as a multi-ply laminate, meaning that there are two or more layers of PET bonded together to make up the film.  For example, Madico’s SafetyShield® 800 film is a two-ply laminate (two x 4-mil layers), while Madico’s SafetyShield® 1500 is a three-ply laminate (3 x 5-mil layers).
  • The Adhesive used to mount the film to glass is a pressure sensitive adhesive which is used to aggressively hold the glass to the film (as opposed to holding the film to the glass as in normal window film).  Once cured, the adhesive will have a peel strength exceeding 5-6 pounds per inch.
  • Both the PET used in the manufacture of the film and the adhesive have UV blockers blended in to protect the film against the damaging effects of the sun.  Consequently, all Madico Security Window Film reduces Ultra-Violet solar radiation by >99%.
  • The outer layer of Madico’s Security Window Film has an acrylic coating to provide scratch resistance.