Continuous Solid-state Polycondensation of Polyesters

The SSP process enables higher molecular weights to be reached which are either technically or commercially not feasible in the melt phase. The main advantages of further increasing the molecular weight in the solid state compared to the melt phase are as follows  

Modem Polyesters Chemistry and Technology of Polyesters and Copolyesters. Edited by J. Scheirs and T. E. Long 2003 John Wiley Sons, Ltd ISBN 0-471-49856-4 

Indeed, the increasing industrial significance of the SSP process can be directly related to the success of the PET bottle. PET was introduced for use in drinking bottle applications in the mid 1970s and the SSP process was required to reduce the AA level below that achievable in the melt phase while increasing 

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