Polyethylene terephthalate (PET) is currently the most commonly used thermoplastic. It is a weakly polar high molecular polymer known for its transparency. Bottle-grade PET is used in processes such as injection stretch blow molding, extrusion, injection molding, and blow molding to produce bottles, sheets, boxes, films, and other products. It finds applications in packaging for beverages, spirits, electronics, pharmaceuticals, and more. Being food-grade, PET is entirely suitable for food and beverage packaging. It can be recycled, cleaned, granulated, and adhesive-enhanced for cyclic use, making it increasingly favored in the food packaging industry.
However, PET has its drawbacks due to its material characteristics. These include a high glass transition temperature and melting point, along with a low crystallization rate, which lead to poor stability, high shrinkage during molding, and difficulty in controlling product forms in the field of engineering plastics. Additionally, PET exhibits poor toughness, low weather resistance, and low surface energy, impacting its electroplating performance and leading to issues such as brittleness and poor adhesion after electroplating.
