Determine the topic of the question-answer pair. Question: "what is Polyester in packaging PET?"; Answer: "Polyethylene terephthalate (sometimes written poly(ethylene terephthalate)), commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers ; beverage, food and other liquid containers ; thermoforming applications; and engineering resins often in combination with glass fiber."? Topic:
Answer:
Polyethylene terephthalate