PPG is a global supplier of coatings, glass, fiber glass, and chemicals. The PPG plant in Tipton, PA, specializes in the manufacture of side, quarter, and rear “lites” (windows) for domestic and foreign automobiles.  Recently, the Tipton plant has made an addition to the production line in which laminated lites are manufactured with a Sungate coating that reflects infrared light.  The coating is critical in reducing the amount of heat produced within the vehicle.  DaimlerChrysler, in particular, has requested this coating be applied to all of their new Mercedes E-class vehicles.    

With the addition of the Sungate coating, the current method of analyzing the glass form is insufficient.  The glass being observed is approximately 1.7 mm in thickness.  The mere weight of the glass itself produces a bend, causing inaccurate measurements and little reproductive accuracy.  The second problem arises with the taper gauge measuring system.  Due to the fragility of the Sungate coating, when the taper gauge comes in contact with the glass surface, the coating is damaged.  The tested piece of glass can no longer be used.  

Approach and Results  

Glass Innovations acted as engineering consultants for PPG in determining an appropriate method of non-contact measurement.  G.I. contacted several North American engineering firms specializing in optics, lasers, line generators, digital cameras, and non-contact measurement systems.  A detailed analysis was conducted on three of the firms that had strong potential in providing PPG with a suitable system.  One of the three companies, Bauer Associates, Inc. in Wellesley, MA, was chosen by G.I. as the best designer of a non-contact measurement system since it satisfied PPG’s specific specifications and tolerances.  

Bauer’s design includes the following:  
 

• A triangulation based measurement system using one digital camera 
• A “user-friendly” system that can be easily understood by manufacturing personnel 
• A system that can be integrated into the current production line. 
• Tolerance of 0.25 mm 
• Reproducibility of 1 sigma. 
• Cost of $100,000

Conclusions  

G.I recommends that PPG uses Bauer’s design for a non contact measurement system since it provides PPG with an accurate and cost effective system.  
 

  Project Objectives

Design Alternatives

  Project Deliverables

Recommendation

  PPG Specifications