Laser transmission welding of polyamide tubes to plates

A major technical hurdle to overcome in making an all-plastic heat exchanger is welding tubes to the base plates of tanks. A heat exchanger that must remove a large quantity of heat quickly requires a large number of tubes, usually closely packed. Various techniques to achieve this have been investigated. The materials for tubes and tank plates were all polyamides; various combinations of PA 66, PA 612 and PPA were studied. Data on successful laser welds are presented.