Link to Elvex main safety products page.

High Impact Safety Glasses!

The new ANSI Z87.1-2003 includes a test for high velocity impact.

Requirement: Spectacles shall be capable of resisting impact from a 6.35 mm (1/4 in) diameter steel ball traveling at a velocity of 45.7 mps (150 fps). For sample size of 20, no failure may occur.

All safety glasses do not have to meet the high velocity impact requirements. However, models that have been tested to this requirement shall carry a marking on the lens or in some cases on the frame. You should find the marking on the lens: E + or on the frame: E Z87+, where E is an example only of a manufacturer's mark. (Each manufacturer has selected a letter or other symbol, so that parts can be identified).

If you want to read more about the test procedures of ANSI Z87.1-2003, please click on this link.

"Elvex UniWraps Safety Glasses, SG-20, have passed Ballistic Resistance requirements of Mil Spec MIL-PRF-31013, clause3.5.1.1. This requirement is 4 times the impact velocity requirement of ANSI for industrial safety applications."

If you want to check out Elvex models that meet the ANSI Z87+ high velocity requirements, click on this link.

How strong is Polycarbonate?

Polycarbonate is used in many applications, such as "bullet proof" windows, and in other applications requiring great flexibility and strength. This material can be molded in opaque or clear material. In clear form it is an excellent material for optical lens manufacturing. Most safety glass lenses are today made from Polycarbonate, or varieties of this material such as Lexan (a General Electric trade mark).

How strong is a Polycarbonate safety glass lens? If you take a look at the illustrations above and below, you will get an idea of the strength of this material. You will see a nail that has been hammered through the lens, and it is now anchored in the lens. Notice that the lens has not shattered or cracked as we might expect.

Elvex UniWraps™, with nail hammered through its center

Model SG-20C

In order to hit the nail through the lens without damaging the glasses, we held a small wood block behind the lens, when we hammered the nail through the lens.

What are the other characteristics of Polycarbonate? One might expect a material that is as strong as Polycarbonate to also be very strong in other respects, such as scratch resistance. In fact Polycarbonate gets its strength from being flexible, so that it gives a little when impacted. Consequently Polycarbonate lenses usually need to be coated with a scratch resistant coating, in order to extend their life span.

Traditional hardened safety glass that was and is still used in safety glass lenses are only one tenth as impact resistant as a safety glass made from Polycarbonate. Glass lenses do not meet the high velocity impact requirements. On the other hand lenses made from hardened glass offer much better scratch resistance, and this is the reason that they are still preferred in some environments.

Blinking Eye

High Impact Safety Glasses!

How strong is Polycarbonate?

Elvex UniWraps™, with nail hammered through its center

E-mail: Info@elvex.com

Copyright © 1997-2007, Elvex Corporation