Safety glass is ubiquitous and takes many forms, ranging from polycarbonate material to glass laminates, and even to aluminum oxynitride ceramic. Safety glass is used in many, many applications (including automotive glass) where some degree of protection from foreign object strike is needed. “Bullet proof” glass laminate safety glass protects bank tellers and store clerks from actions of violent criminals. Polycarbonate lenses in safety glasses protect worker’s eyes. Any application where transparency is required but potential for damage from some sort of projectile is possible is a candidate application for safety glass. Rock strike damage, crack propagation, and delamination are known issues with laminated safety glass as is readily evident by the numbers of “free windshield repair” entrepreneurs gracing shopping mall parking lots and major street intersections. Those repair costs may be free to the auto owner but not to his/her insurance company. Data on the total cost to insurance companies isn’t available but is certain to be enormous.
Two current Army problems with safety glass, which the project will eliminate, are damage caused by rock strikes in military convoys and delamination of the layers. Damage to safety glass requires replacement; therefore both of these problems have increased the logistical and life cycle costs to the Army. The same problems plague auto and truck owners. Learning from this Army test bed can be extended to commercial automotive applications.
The intended solution for this project is to decrease the life cycle costs to the Army by developing safety glass without significantly increasing the weight or the cost of the solution. For the rock strike problem this can be in the form of, but not limited to, new sacrificial strike plies that can be replaced/repaired in the field, or coatings that increase the materials resistance to strike damage. For the delamination problem will be approached from three perspectives. The first is to develop new interlayers, or coatings, that would decrease delamination. The second is to investigate the effect of processing parameters on delamination. Thirdly investigate the effect of integration of the safety glass to metal frame work on delamination.
Those interested in participating in this initiative should contact Tony Haynes, (734) 995-4930