What is EdgeGuard, how does it work, and why is it of value to you?

What is EdgeGuard?

EdgeGuard is a patented application of a thin, transparent layer of high-impact, durable plastic installed around the outer edge (2-3'') of your windshield. 

What does it look like installed on a windshield?

Very much like the windshield wipers, rear view mirror, and windshield itself, drivers and passengers alike very quickly forget it's even present.

Even though the EdgeGuard material is around the entire perimeter of the windshield, it's only visible on the lower passenger side of the windshield.


View of EdgeGuard from inside the same vehicle; passenger side. Note: field of view not impaired.

What does EdgeGuard do?

Hard as it may initially be to believe (see below) , it prevents the leading cause of windshield replacements from occurring.

How can a piece of plastic installed around the perimeter of a windshield prevent cracks that can lead to your windshield needing to be replaced?

Because of the way windshields are manufactured, bending and rapid cooling of the glass results in stresses being concentrated in the outer 2-3" of the windshield.  These "manufacturing" stresses are further amplified when the windshield is installed within the rigid frame of your vehicle.  This effect is documented in a study conducted by engineers at Daimler Chrysler and Stress Photonics in a paper entitled "Windshield Investigation - Manufacturing and Installation Stresses" published in 1999 by the Society of Automotive Engineers.  Photographs taken using a stress-indicating polariscope illustrate this effect.

Outer edge of windshield prior to installation showing manufacturing stresses.


Same area of windshield after installation showing manufacturing & installation stresses.

Stresses within materials naturally seek to be relieved.  One way this can be accomplished is by cracking - the greater the stress, the easier it is to crack the material.  When a piece of road debris strikes your windshield, it may or may not crack the glass - it all depends on the energy the debris transmits to the glass and the amount of stress inherent it the area it strikes.  Because the outer 2-3" perimeter of the windshield has a much higher concentration of stress than the inner portion, the likelihood of a given piece of debris causing a crack is significantly greater when it hits the outer perimeter vs. the center. 

This was proven out by an independent study carried out by Knott Laboratory published in a paper entitled "A New Polycarbonate and Glass Laminate and Its Affects on the Relationship Between Residual Tensile Stresses and Impact Resistance of Windshields" also published in 1999 by the Society of Automotive Engineers.  In this study, windshields from six different manufacturers were tested for the amount of energy required to initiate cracks in different areas of the windshield.  They found on average that the amount of kinetic energy required to cause a crack in the center of the windshield was over 2.5 times greater than on the outer 2-3" perimeter!

We've also confirmed this phenomenon in the real world.  In surveys of over 10,000 vehicles in shopping mall parking lots, 83% of all windshield cracks were initiated by an object striking the vulnerable outer 2-3" area of the windshield - the very same area protected by EdgeGuard.

To evaluate the effectiveness of EdgeGuard, the Knott's Laboratory study also compared the amount of energy required to cause a crack the perimeter area of windshields protected and not protected with EdgeGuard.  In this portion of the study, they found that on average, the amount of energy required to cause a crack was over 1.8 times greater in areas protected by EdgeGuard vs. those that were not.

Still not convinced?  Consider the following analogy.  A windshield is like a baseball batter.  Both have objects thrown at them.  The batter has a vulnerable area he or she protects - their head.  The windshield has a vulnerable area as well - its perimeter.   The batter protects his or her head with a helmet.   The windshield can be protected by EdgeGuard.

OK, that's all nice - so what?  Why do I care if I have a cracked windshield?

Several reasons:

  1. Your windshield plays a critical role in protecting you and your passengers in the event of an accident. A damaged windshield significantly increases your chances of head and neck injuries in a roll over! To learn more, click here .
  2. It's important to keep your original windshield for as long as possible.  Your original windshield is the safest windshield your vehicle will ever have. To learn more, click here .
  3. It's a hassle to get your windshield replaced and chances are, it won't be done properly. To learn more, click here .

By prolonging the life of your original windshield for as long as possible, EdgeGuard maximizes your safety and reduces the time and money you spend replacing windshields.

EdgeGuard is also friendly to the environment in that it reduces the number of windshields sent to landfills.

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EdgeGuard Inc.
2458 East Main St., STE B1
Grand Junction, CO. 81501

Tel: (970)256-0200
Fax: (970)256-1786







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