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US 6,521,155 B1Granted
Chimney-pipe and manufacture of same
OwnerHorst Wunschinventor
Life of this patent
Estimating the term…
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.
Claims10
A process for manufacturing plastic pipe from a recycled, crushed PET starting material comprising:
- providing a source of recycled, crushed PET starting material;
- feeding the starting material to a kneading unit;
- kneading the starting material under the influence of heat and removing moisture from the kneading unit to prevent hydrolysis and to form a homogenous, substantially moisture free, process viscous mixture;
- feeding the viscous mixture to an extruder;
- and
- providing the extruded mixture to a corrugator while cooling at a temperature gradient of between −10° C./min and −50° C./min so as to form a crystalline plastic pipe.
3 more elements
Dependencies are inferred from the claim text.