scope:

Abstract:

A video clip lesson learned on the topic of Process Control. A ?squeegee,? a wafer-thin wedge of plastic, is used on the Space Shuttle Solid Rockets to apply the adhesive that bonds critical insulation to the inside of the motor case. Silicone is widely used throughout industry as a release agent. In this use, it cannot be allowed to contaminate adhesive application tools? even in trace amounts. Its introduction into the adhesive application process can weaken bonds and allow hot gases to force a path between the insulation and the metal case. The supplier delivered squeegees that tested positive for trace amounts of silicone despite clear specifications prohibiting it. The supplier believed it had met this requirement because no silicone was used in the material used to form the squeegee. However, an investigation determined that the supplier had used a silicone-based release agent to ease squeegee removal from the manufacturing molds. If the supplier had known the reason for the no-silicone specification, they would have understood the mission-critical implications of silicone contamination on Space Shuttle components. Clear communications between customers and suppliers is critical to maintaining process control. This 3-minute, 15-second video is a product of the Space Shuttle Program and its Process Control Focus Group.