Polyethylene terephthalate (PET) plastic is used to produce fibers and yarn, engineering plastics, photo and packing film, beverage and food containers.
PET is produced in the reaction of monomers purified terephthalic acid (PTA) and ethylene glycol (EG) in the presence of catalyst. In the reaction, there's excess EG and other reaction products such as s propylene glycol (PG) and triethylene glycol (TEG) which are later recovered and recycled.
It is important to measure reliably the concentration of EG in the recycling line in order to maintain the reactor feed at the desired level. The concentration of the EG feed has an important effect on the quality and opacity of the polymer product.
Vaisala K-Patents® Process Refractometer is used to measure the concentration of ethylene glycol in the recycle stream. The measurement taken by the refractometer helps adjust the feed ratio of fresh EG to ensure the correct quantity is fed to the reactor.
Learn the details of the polyethylene terephthalate production process from the application note.
Download the application note in PDF by filling the form.
Go back to all Chemicals & Allied Products applications