Off the Line
news about glass and autos
Windshields and Standards
by Monica Mathews
This issue of AGRR heralds the new AGRSS standards. These standards concern the
replacement of auto glass, but any safety equation must include a look at the materials
Windshields are part of that equation, too. The U.S. and Canadian governments have written into law an approved American National Standards Institute (ANSI) standard (Z26.1) which outlines the minimum acceptable performance requirements of windshields. Making a windshield that only meets those standards is comparable to handing someone a spoon to dig a hole.
Vehicle manufacturers have input into the design of windshields. They know that design and styling are two of the most important features of a vehicle that will influence a consumers purchase decision. Vehicle manufacturers design windshields to both complement their vehicles and simultaneously act as crucial components for performance.
The OE glass suppliers work closely with the vehicle manufacturers during the design and production stages. They have the ability to take the vehicle manufacturers design and determine whether it can be produced and can also make recommendations that will improve the design and make sure that it is able to be manufactured. They then put the design through computer simulation to make sure that the final product can be manufactured free of defects and distortion. Finally, they use the improved design to support the building phase of the production tools. When at last the parts are produced, they are tested to confirm the product meets all requirements, from governmental to the specific vehicle design through vehicle manufacturing, including meeting the final consumers needs.
There are low- and medium-grade windshields that have not been put through all the internal and external testing required of a high-quality windshield such as one from an OE manufacturer. Some performance characteristics may not have as strong of an impact to the safety and performance of the vehicle, but some things, such as premature aging of the plastic laminate in the windshield, do have an impact. If the laminate does not bond well to the glass, there may be potentially dangerous repercussions in the event of a vehicle crash. A windshield is also in the car to protect the occupants and keep them in the vehicle in the event of crashes.
Testing done on quality windshields such as Pilkingtons include visual inspection, ball drops, optical properties, heat tests, break-pattern tests, stress analysis, mirror-mount adhesion, plastic laminate adhesion, moisture checks, dimensional checks, monogram checks and paint-band adhesion, opacity and appearance. These tests all serve to assure that the product will perform as intended.
I applaud the AGRSS Council for a job well-done in getting the standard approved. I know it has been a long time in the works. We all need to be more aware of the products we are using and the process with which we use them. It is not acceptable to buy the best products and then not follow the directions for using them, nor should we skimp on the products and try to make it up in the end.
Monica Mathews works in the auto glass replacement division of Pilkington North America in Columbus, Ohio, as a technical services specialist.
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