Polypropylene films produced by the casting process

Cast polypropylene film (cpp) is a polypropylene film produced by the casting process, which can be divided into general-purpose CPP film, aluminised grade CPP film and cooking grade CPP film.

It can be divided into General CPP (General CPP, referred to as GCPP) film, aluminised grade CPP (Metalize CPP, referred to as MCPP) film and retort CPP (RCPP) film. It has good transparency, uniform thickness and uniform longitudinal and transversal properties, and it is generally used as the inner material of the composite film. Ordinary CPP film thickness is generally between 25 ~ 50μm, and OPP composite transparency is good, bright surface, feel firm, general gift bags are used in this material. This film also has good heat sealability. Cooking grade CPP film thickness is generally between 60 ~ 80 μ m, can withstand 121 ℃, 30 min of high-temperature cooking, oil resistance, airtightness is better, and the heat sealing strength is higher, the general meat packaging inner layer of the cooking grade CPP film.

According to industry insiders, in the world market of packaging materials, cast film production is a continuous upward trend, cast film industry is entering a new round of investment boom. China's cast film production started in the 1980s, with nearly 20 years of continuous development and growth in the packaging industry has become a considerable production capacity and production level of the sunrise industry.

Polypropylene cast film (CPP) is a non-stretch, non-directional flat extruded film produced by melt cast quenching. Compared with blown film, it is characterised by fast production speed, high yield, good film transparency, gloss, thickness uniformity and excellent balance of properties in all directions. At the same time, because it is flat extruded film, subsequent processes such as printing, laminating, etc. is extremely convenient, and therefore widely used in textiles, flowers, food, daily necessities of packaging.

CPP can be produced in two ways: single-layer casting and multilayer co-extrusion casting. Single-layer film mainly requires low-temperature heat sealing performance and flexibility of the material. Multi-layer co-extrusion cast film can generally be divided into three layers of heat sealing layer, support layer, corona layer, in the choice of materials wider than the single-layer film, can be individually selected to meet the requirements of each level of the material, endowed with different functions and uses of the film. Among them, the heat sealing layer should be processed for heat sealing, which requires low melting point of the material, good hot melt, wide heat sealing temperature, and easy sealing; the support layer plays a supportive role for the film to increase the film's stiffness; the corona layer should be processed for printing or metallisation, which requires moderate surface tension, and there should be strict limitations on the addition of additives.

CPP can be used individually for the outer packaging of foodstuffs, garments, sanitary napkins, flowers, etc. after printing and bag making. In addition, because of its excellent transparency, low heat sealing temperature, can also be used as a variety of composite film base film, such as composite with PET film, BOPP film, etc., for packaging fast food products, tea, etc.; and barrier resins EVOH, PA, PVDC, etc., through the adhesive composite, to package food containing oil or soup. Others such as high and medium temperature cooking film, vacuum aluminised film are also important application areas.

With the increasing market demand, cast film products and materials used are also increasingly updated. new product development of CPP mainly focuses on ultra-low temperature heat sealing film, cold-resistant film, high-temperature cooking film and so on. Some special-purpose films are also being developed and applied, such as anti-static film, pesticide film, highly transparent and super-soft film, etc., which are gradually being introduced to the market and occupying new application fields.

Nanjing Suminoe Precision Machinery Co., Ltd. has professional sheet production line, the company's main sheet machine manufacturing production line: PET/PRET sheet production line, PP sheet production line, PP vacuum profile extrusion line, PP/PC vacuum sheet production line, PC/PP corrugated sheet production line, PVDF photovoltaic backing sheet production line, PMMA acrylic sheet production line, PE waterproofing membrane production line, high-performance barrier sheet production line. High-performance barrier sheet production line, optical panel production line, multilayer co-extruded sheet production line, etc.