Process for production of directly spinnable poly(ethylene terephthalate)
Abstract
Abstract A PROCESS AND INSTALLATION THEREFOR TO PRODUCE A SPINNABLE POLYESTER COMPOSITION AND IS PARTICULARLY CHARACTERIZED IN THAT PULVERIZED DIMETHYLTEREPHTHALATE (DMT) AND ETHYLENE GLYCOL ARE FIRST MIXED TO FORM A HOMOGENEOUS PASTE (PREFERABLY IN A SCREW EXTRUDER WITH MESHING SCREWS AND HAVING A VERY SHORT DWELL TIME), THEN THE PASTE IS MELTED AND HEATED TO ITS ESTER-EXCHANGE TEMPERATURE AND IS AGITATED AT HIGH SPEED (PREFERABLY USING TWIN PADDLE SCREWS WITH PILGRIM-STEP OR RECIPROCATING STEP MOTIONS). AFTER THE ADDITION OF A SUITABLE CATALYST, THE MIXTURE IS INTRODUCED TO A SERIES OF SCREW-CONVEYOR TYPE REACTORS AT A TEMPERATURE OF ABOUT 280 DEGREES CELSIUS (536 DEGREES FAHRENHEIT) AND AT PRESSURES DECREASING FROM ABOUT 60 TORRS ABSOLUTE DOWN TO FROM 0.1 TO 0.3 TORR ABSOLUTE WITH THE GLYCOL CONTENT FROM 1% TO 3% AND THE VISCOSITY FROM 100 TO 300 POISES IN THE LAST REACTOR.
Inventors
- 👤 Herbert Ocker
Bibliographic Details
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