PET heat-seal film Manufacturers refer to PET polyester film simply as PET film. It is characterized by its high-temperature resistance, excellent printability, ease of processing, superior dielectric strength and insulation properties, and fire‑retardant compliance with UL 94 VTM‑2 certification, as well as environmental certifications from SGS and RoHS. The material is produced by extruding a thick sheet from polyethylene terephthalate resin and then subjecting it to biaxial stretching. It appears as a colorless, transparent, glossy film with outstanding mechanical properties, including high rigidity, hardness, and toughness, along with resistance to puncture, abrasion, extreme temperatures, chemicals, oils, air permeation, and the retention of fragrance. As such, it is one of the most commonly used base materials for barrier composite films. However, PET film tends to be relatively expensive, typically available in a thickness of 0.12 mm. It is frequently employed as an outer layer in food‑processing and packaging applications, offering excellent printability.

　　PET heat-seal film manufacturers contend that PET film boasts excellent physicochemical properties, dimensional stability, transparency, and recyclability, making it suitable for a wide range of applications, including magnetic recording, photosensitive materials, electronics, electrical insulation, industrial films, and packaging and decorative uses. With the advancement of specialty functional polyester films, new applications continue to emerge.

　　PET heat-seal film manufacturers define polyester film as a thin film produced from polyester chips as the primary raw material, using advanced processing formulations and undergoing drying, melting, extrusion, cast‑film formation, and stretching. It boasts excellent transparency, gloss, superior gas barrier properties, long-lasting fragrance retention, moderate moisture resistance, and outstanding mechanical performance, making it widely used in industries such as liquid crystal displays, medical packaging, electrical appliances, and new energy.

　　PET heat-seal film manufacturers classify polyester films according to their thickness into ultra-thin, thin, medium‑thickness, and thick types. Among these, the thin and medium‑thickness grades are generally referred to as general‑purpose films, with thicknesses typically ranging from 6 to 65 µm, and are primarily used in packaging and related applications. In contrast, ultra‑thin and thick films are classified as specialty films and are mainly employed in other industrial sectors.

　　PET heat-seal film manufacturers classify polyester films into uniaxially stretched polyester film and biaxially stretched polyester film, depending on the stretching process. Uniaxially stretched polyester film (abbreviated as CPET) is produced by using a semi‑matte material—prepared by adding titanium dioxide to polyester resin pellets—followed by drying, melting, extrusion, cast‑film formation, and longitudinal stretching. It is the lowest‑grade and most cost‑effective type of polyester film. Biaxially stretched polyester film (abbreviated as BOPET) is a mid‑to‑high‑grade film made from a bright‑finish material; it is also referred to as a bright‑finish material, meaning that the raw polyester pellets contain 0.1% titanium dioxide. This material undergoes drying, melting, extrusion, cast‑film formation, and horizontal biaxial stretching. With its wide range of applications, BOPET has been extensively adopted across numerous industries and continues to expand into new areas.

　　PET heat-seal film manufacturers note that the primary raw materials for polyester film are polyester chips, PTA (purified terephthalic acid), and MEG (ethylene glycol), making it one of the most widely used film materials. Its downstream applications have steadily expanded to encompass packaging, electronic information, electrical insulation, aerospace, construction, agriculture, and other manufacturing sectors.