Method and apparatus for infrared welding of thermoplastic parts

Apparatus for heat welding thermoplastic materials with infrared radiation comprising:

• an energy source for producing radiation in the infrared band;
• and
• a radiation-directing structure for directing radiation from the source to an area to be welded;
• said structure including,
• (a) a first reflector which at least in one cross-sectional plane is parabolic and has a focus;
• and
• (b) a second reflector joined substantially end to end with the first reflector and having, at least in said cross-sectional plane, a non-imaging shape and an aperture at an end remote from the first reflector;
• said source being essentially located at said focus whereby radiation from the source is collimated by the first reflector and caused to emerge essentially entirely through said aperture.

A method of thermally fusing thermoplastic materials in an abutting or layered relationship comprising the steps of:

• providing a source of infrared radiation;
• collimating the illumination from the source using a first reflector the reflective portions of which are parabolic in at least one cross-sectional plane;
• and
• directing the radiation toward the layered thermoplastic materials to be welded.