Abstract: A process for manufacturing a plastic pipe from recycled crushed PET starting material includes kneading the starting material under the influence of heat while removing moisture therefrom so as to prevent hydrolysis of the PET material and thereafter feeding the mixture to an extruder and passing the extruded mixture to a corrugator while cooling at a temperature gradient of between −10° C./min and −50°/min so as to form a crystalline plastic pipe.

Abstract: Metal-foil insulation formed of a multiplicity of substantially rectangular-shaped, air-enclosing metal foils disposed laterally adjacent and above one another and provided with spacers therebetween, the metal foils being packageable in thermally displaceable relationship into panels with connecting means for maintaining the foil in packaged condition, the panels, in turn being mutually alignable with sealable joints in a plurality of coordinate directions, includes bends formed in marginal zones of at least one side of an upper and a lower side of the metal foils in the respective panels, the bends having a shape and a shape elasticity such as to be deformable by a packaging force to a spacing between mutually adjacent metal foils determined by the spacers therebetween, the metal foils packaged into the respective panels being disposed with the bends thereof substantially linearly and sealingly engaging one another.