During this stage of the PET process, the molecular chain length is extended to increase the viscosity and hence the strength of the final polymer. Most of the equipment in the Solid State Polymerization (SSP) facility was supplied by Būhler.
Amorphous chips from the 266 CuM feed Silo are fed by gravity through a 6 TPH rotary airlock into the 5 SqM Būhler crystallizer, which heats and dries the chips and begins the crystallization of the chips. Process air is circulated around a loop and a slight purge from the loop (to atmosphere) allows removal of moisture and acetaldehyde from the drying and crystallization process. Product leaves the crystallizer by displacement over an adjustable weir plate and is fed forward into the reactor. The crystallizer is actually fluid bed dryers from Būhler and made of stainless steel.
From the crystallizer, chips are fed into the top of the reactor, where a combination of gas temperatures and residence time within the reactor control the final chain length (IV) of the product leaving the reactor. The reactor was built by KSK out of 1.4541 stainless steel. The hot chips leave the reactor an pass through a water cooled chip cooler, then into (2) Mutschnk multi stage spin dryers. From the dryers the chips are conveyed to the 48 Cu M 1.4541 SS Chip Silo, before transfer to bulk storage.
Click Here to View the SSP1 Flow Diagram