| abstract |
A method and apparatus for extruding a radiant energy heat exchanging panel structure (10) having a multiplicity of parallel passages (14, 22, 28 or 34) extending longitudinally therethrough defined by a multiplicity of longitudinally extending integrally interconnected exterior and interior thin wall sections (16, 18, 20, 24, 30, 26), in which the temperature of the plastic material moving longitudinally away from the extrusion outlet (66, 68, 70, 72, 74, 76) is reduced by flowing fluid (92, 96, 100, 104, 114) into said passages and on the exterior sides thereof, by contacting the exterior sides with pairs of cooled rollers (148, 184), by rolling a liquid medium (153) upon the operative exterior side, and by flowing a liquid spray (240) thereon to provide a radiation absorbing coating on the exterior side of the panel structure opposite from the operative side thereof. Certain of the flowing fluids are reactant fluids which chemically react with the hot plastic material or condense thereupon to form molecular coatings thereon enhancing the properties thereof as a panel structure. |