What is the Polypropylene Film?
The polypropylene film is produced by first forming the polymer polypropylene melt into a sheet or a thick film through a narrow head, and then at a certain temperature and a set speed in a dedicated stretching machine, simultaneously or separately. The film is stretched in two perpendicular directions (longitudinal, transverse) and subjected to appropriate cooling or heat treatment or special processing ,such as corona, coating, etc.. Commonly used polypropylene films include: conventional biaxially oriented polypropylene films, heat-sealed biaxially oriented polypropylene films, cigarette packaging films, biaxially oriented polypropylene pearl films, biaxially oriented polypropylene metallized films, matt films, etc. .
Polypropylene film is a very important soft packaging material. Polypropylene film is colorless, odorless, odorless, non-toxic, and has high tensile strength, impact strength, rigidity, toughness and good transparency. The surface energy of polypropylene film is low, corona treatment is required before gluing or printing. After corona treatment, the polypropylene film has good printing adaptability, it can be color-printed to obtain a beautiful appearance, and is therefore often used as a surface layer material of a composite film.
|Polypropylene film also has deficiencies, such as easy accumulation of static electricity, no heat sealability and so on. In a high-speed production line, polypropylene film is prone to static electricity and an electrostatic remover is required. In order to obtain a heat-sealable polypropylene film, a heat-sealable resin adhesive such as PVDC latex, EVA latex, etc. may be applied after the corona treatment on the surface of the polypropylene film, or a solvent adhesive may be applied, and extrusion coating or coating may be used. The co-extrusion method produces a heat-sealable polypropylene film. The film is widely used in the packaging of bread, clothes, shoes and socks, and the cover of cigarettes and books. The tearing strength of polypropylene film is improved after stretching, but the secondary tearing strength is very low. Therefore, no cuts can be left on both ends of the polypropylene film, otherwise the polypropylene film is easily torn during printing and compounding. After polypropylene coating adhesive can produce sealing tape, it is a market with a large amount of polypropylene.|