L. Triplett, J. DeAntoni, The Boeing Company, St. Louis, MO

Summary:

Boeing is working toward ways to reduce environmental and worker safety concerns and benefit from improved productivity. The most recent pressure to minimize hexavalent chrome is driven by OSHA’s Notice of Proposed Rule Making in October 2004 that proposes reducing the permissible exposure limit (PEL) from 52.0 to 1.0 ug/m³. There is also continued pressure for VOC reduction beyond the Aerospace NESHAP limits. When evaluating alternatives to reduce chrome and VOCs it became apparent that there were other potential benefits. A key aspect of lean manufacturing is creating product flow while eliminating non-value added steps. One common, non-value added step is the movement of assemblies from assembly to a paint facility and back to the assembly line. This non-value added movement of parts increases cycle time and adds cost. Paint-on-the-line is an effort to improve productivity by eliminating the need to move parts to a paint booth for paint application.

Technology elements necessary for paint-on-the-line are non-sanding methods of primer reactivation to avoid chromate containing dust during pre-paint preparation and intrinsically safe Zero VOC coatings that contain effective nonchromate corrosion inhibitors. Near term coatings are being developed for Boeings paint-on-the-line initiatives that have a conventional chemical cure and longer term coatings that can be cured with Ultra Violet (UV) light. Coatings undergoing testing are Zero VOC, nonchromate waterborne primers and topcoats and Zero VOC self-priming UV cured coatings. There are much greater technical challenges with UV cured coatings but they can cure in seconds, rather than hours and can be formulated as 100% solids. Paint-on-the-line provides many technical challenges, but offers significant environmental and productivity benefits to The Boeing Company.