Many industrial applications require optically transparent thermoplastic components and structural joints almost invisible to the human vision. Traditional transmission laser welding of plastics joining is limited by the process conditions when one thermoplastic is optically transparent and the second absorbing laser energy. Advanced Clear-Weld (clear-welding)1 laser technology may satisfy these specific requirements in joining various similar and dissimilar optically transparent thermoplastics. These innovative design-joining technology considerations require the following conditions at the interface between the joined surfaces: 1) laser absorbing material; 2) optimized laser energy for heat generation between joined thermoplastics. The analysis of representative test results shows that clear-welding technology is highly efficient also for use with various transparent nylon grades. The tensile strength of the clear-weld butt joint is similar to the results achieved for nylon with other advanced plastics joining methods such as linear, orbital, hot plate and regular infrared (laser through-transmission) technologies. The developed comprehensive recommendations will help designers and technologists with welded parts design, material(s) and process selection and optimization for laser welding applications when the joined thermoplastic part requires optical transparency, as well as flash and particle free conditions.

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