BOPP heat-seal film It is a highly important flexible packaging material. BOPP heat-seal film is colorless, odorless, tasteless, and non‑toxic, and it boasts high tensile strength, impact resistance, rigidity, toughness, and excellent transparency. Due to its low surface energy, BOPP heat-seal film requires corona treatment prior to adhesive coating or printing. After corona treatment, it exhibits excellent printability, enabling multi‑color overprinting for an attractive appearance, which is why it is commonly used as the surface layer in composite films.

　　Commonly used BOPP heat-seal films include: standard biaxially oriented polypropylene, heat-sealable biaxially oriented polypropylene, packaging film, pearlescent biaxially oriented polypropylene film, metallized biaxially oriented polypropylene film, and matte‑finish film, among others.

　　BOPP heat-seal films are prone to static buildup and lack inherent heat‑sealability. On high‑speed production lines, static electricity can easily accumulate, making the installation of an electrostatic eliminator necessary. To produce heat‑sealable BOPP films, their surfaces can be corona‑treated and coated with heat‑sealable resin adhesives, such as PVDC latex or EVA latex, or with solvent‑based adhesives. Heat‑sealable BOPP films can also be manufactured via extrusion coating or co‑extrusion, and are widely used for packaging bread, clothing, footwear, and socks, as well as for book cover laminates. After stretching, the initial tear strength of BOPP film improves, but its secondary tear strength remains very low. Consequently, BOPP film should not be slit at both ends, as it is easily torn during printing and lamination. When coated with pressure‑sensitive adhesive, BOPP can be used to produce sealing tape, a market segment with substantial volume.

　　BOPP heat-seal films can be produced using either the tubular‑film or flat‑film process. The properties of the film vary depending on the manufacturing method. Films produced by the flat‑film process, which typically employs a higher draw ratio (up to 8–10), exhibit greater tensile strength and superior thickness uniformity compared to those made by the tubular‑film process.

　　To achieve superior overall performance, multilayer lamination is commonly employed during production. It can be combined with a wide range of materials to meet specific application requirements. For example, it may be laminated with LDPE (CPP), PE, PT, PO, PVA, and others, yielding enhanced gas barrier properties, moisture resistance, transparency, resistance to high and low temperatures, retortability, and oil resistance. Different composite films are suitable for packaging oily foods, delicacies, dried goods, dipping sauces, cooked foods, monosodium glutamate, pancakes, rice cakes, and more.

　　BOPP heat-seal film manufacturers consider that standard films and intermediate‑grade films are generally classified 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 categorized as specialty films, mainly serving other industrial sectors. Among these, PET film boasts excellent physicochemical properties, dimensional stability, transparency, and recyclability, making it widely applicable in magnetic recording, photosensitive materials, electronics, electrical insulation, industrial films, and packaging and decorative applications.