Patent ID: 8354051

Claim:
A method of thermally treating thermoplastic parisons for use in blow molding operations, the method comprising the steps of: transporting a series of parisons through a path of a heating unit of a blow molding machine, wherein each of the parisons has a neck and the heating unit is configured to heat the parisons while the parisons are oriented neck up in the heating unit; irradiating the parisons using one or more sources of coherent electromagnetic radiation at one or more wavelengths in a wavelength band between 700 nm and 1600 nm; and heating the parisons to at least one desired temperature, wherein the path is defined by opposing a first wall and a second wall which comprises: slits disposed on a side of the second wall proximate the path, and the sources of coherent electromagnetic radiation which are disposed on other side of the second wall, distally from the path, and emit the coherent electromagnetic radiation through the slits across the path toward the first wall and across substantially an entire length of a body of each parison which follows the path.