For more than 30 years, manufacturers have used infrared welding (IW) to assemble plastic components that are large, made of challenging materials or have high strength and hermetic requirements. During IW, two part halves are rigidly held in position near an infrared emitting platen to melt the joining surfaces. The platen is then removed, and the part halves are squeezed together and resolidify under pressure.
About four years ago, Shanghai-based Yanfeng Automotive Interiors installed an IW machine at its Louisville, KY, facility to assemble plastic parts of the defroster grille for the Ford Escape. After a short while, however, plant management realized that it needed to do a visual check of the welded parts to verify quality. This check required a stoppage of production and involved pulling apart welded parts.