Process for manufacturing a hollow body and the manufactured body

A process for manufacturing a gasoline tank or a filler pipe for a gasoline tank, a diesel tank and/or a filler pipe for a diesel tank comprising

• providing a extrusion-blow molding machine comprising
• a coextrusion head comprising at least one extruder and configured to manufacture at different time periods, a first multilayer parison comprising a barrier layer and a second multilayer parison that does not comprise a barrier layer, and
• said extruder being connected to a feeding line which is connected to a hopper,
• said hopper being connected
• by a first inlet to a source of a first material for pushing said first material towards said extruder to form said barrier layer of said first multilayer parison and
• by a second inlet to a source for a second material for pushing said second material towards said extruder to form said non-barrier layer of said second multilayer parison,
• wherein said first inlet and said second inlet are controlled such that said first material and said second material enter the hopper one at a time;
• during a first period of time
• extruding the first multilayer parison comprising the first material with the extrusion-blow molding machine, and
• blow-molding the first multilayer parison to form a gasoline tank or a filler pipe for a gasoline tank;
• during a second period of time
• stop pushing said first material towards the extruder by closing the first inlet, and
• start pushing said second material towards the extruder by opening the second inlet;
• during a third period of time
• extruding the second multilayer parison comprising the second material with the extrusion-blow molding machine, and
• blow-molding the second multilayer parison to form a diesel tank or a filler pipe for a diesel tank;
• wherein the first material is a fuel-impermeable resin, and
• wherein the second material is high density polyethylene or a mixture of high density polyethylene and adhesive.