Process and an apparatus for manufacturing bi-axially oriented polyester film from RPET
AssigneePolyplex Corporation Limited
InventorsPranay Kothari, Krishna Reddy
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Abstract
The present disclosure relates to a process for producing bi-axially oriented polyester (BOPET) film from the recycled polyethylene terephthalate (RPET) granules. The process involves preparing recycled PET (RPET) granules form post-consumer recycled PET (PCR PET) by depolymerization and polycondensation followed by preparing the biaxially oriented polyethylene terephthalate (BOPET) film having recycled polyethylene terephthalate (RPET) up to 100%. The bi-axially oriented polyester film has good elongation, mechanical and/or thermal properties and are similar in quality to virgin PET films useful in high end food and pharma packaging and industrial applications.
Claims13
A process for preparing a biaxially oriented polyethylene terephthalate (BOPET) film comprising, the steps of
- preparing a recycled polyethylene terephthalate (RPET) granules, comprises
- depolymerization by glycolysis of a pre cleaned PET products to produce monomers,
- polycondensation of monomers in a polycondensation reactor or an autoclave to produce recycled PET (RPET) granules,
- preparing the biaxially oriented polyethylene terephthalate film, comprises
- charging the RPET granules optionally along with a virgin PET granules, to an extruder to obtain a molten polyethylene terephthalate,
- extruding the molten polyethylene terephthalate through a die,
- quenching the extruded polyethylene terephthalate on chilled rollers and stretching to obtain biaxially oriented polyethylene terephthalate film,
- characterized in that, the glycolysis reaction is conducted in an esterification reactor by addition of glycol, at a temperature of 245-255° C. and at a pressure of 0.5-1 bar, and the RPET granules are charged to the extruder up to 100% for industrial applications in the mixture of the RPET and virgin PET granules, charged to the extruder or up to 90% for food or pharma packaging applications in the mixture of the RPET and virgin PET granules, charged to the extruder.
An apparatus for producing biaxially oriented polyethylene terephthalate (BOPET) film comprises,
- cleaning device for pre cleaning PET products to be recycled,
- esterification reactor for converting a pre cleaned PET product to a monomer,
- autoclave reactor operated at temperature of 275-295° C. and at vacuum pressure, for polycondensation of the monomers to obtain a recycled PET granules,
- extruders for extruding the recycled PET granules and optionally a virgin PET granules to obtain the molten polyethylene terephthalate (PET),
- chilled rollers for quenching the molten PET and stretching to obtain biaxially oriented polyethylene terephthalate,
- characterized in that, the esterification reactor involves glycolysis reaction by addition of glycol, at a temperature of 245-255° C. and at a pressure of 0.5-1 bar, and
- the RPET granules are charged to the extruder up to 100% for industrial applications in the mixture of the RPET and virgin PET granules charged to the extruder or up to 90% for food or pharma packaging applications in the mixture of the RPET and virgin PET granules, charged to the extruder.
Dependencies are inferred from the claim text.