Process for assembling tubes of plastics material and assemblies resulting from said process

Claim 1

Process for manufacturing a heat exchanger having parallel tubes and radiating plates assembled with the tubes, comprising simultaneously extruding in extruders a series of coplanar laterally spaced-apart parallel tubes of thermoplastic material having an elastic memory; simultaneously drawing by pulling the extruded tubes through die heads coaxial with the outlets of the extruders and having a cross-sectional size less than the cross-sectional size of the tubes issuing from the extruders, the tubes being cooled down to a temperature in the neighbourhood of the softening point of said material before entering the die heads; simultaneously passing the tubes issuing from the die heads through a cooling tank while maintaining the pulling force on the tubes; feeding two radiating plates on both sides of the series of tubes issuing from the tank in contact with opposed generatrices of the tubes; press-forming the two plates so that the plates conform to the shape of the tubes and come in contact with each other in regions thereof corresponding to the lateral spaces between the tubes; fixing the plates together in said regions, and reheating the assembly of the tubes and the plates to said temperature.