Patent ID: 8343299
Filing Date: 2013-01-01
Classification: B29C,B29K,B29L

Abstract:
1. A method for welding first and second plastic parts in a low absorption through-transmission infrared welding process wherein the parts are tubular parts with the first part coaxially surrounding the second part and the tubular parts are surrounded by a mirror, the method comprising; directing a beam of infrared laser light from a source of infrared laser light to the parts where it impinges the first part, transits through the first part to a weld interface at a junction of the first and second part where there is low absorptivity to infrared laser light at the weld interface, and a portion of the infrared laser light passes through the second part and exits the second part, the infrared laser light exiting the second part being unabsorbed infrared laser light; refracting the infrared laser light with the tubular parts as the infrared laser light passes through the tubular parts so that the unabsorbed infrared laser light is fanned out; and redirecting with the mirror surrounding the tubular parts the fanned out unabsorbed infrared laser light back to the weld interface in an infinite loop where the redirected infrared laser light impinges and transits through the first part, is partially absorbed at the weld interface, and a portion of the redirected infrared laser light not absorbed continues through the second part and exits a far side of the second part wherein in each pass of the infinite loop, more infrared laser light is absorbed at the weld interface.