Classification Logic: Dual Dimensions of Material and Process

The classification system of plastic films centers on polymer materials, forming a multi-level technical map by combining molding processes and functional characteristics. The current mainstream classification covers eight major substrate types, including polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyester (PET), nylon (PA), etc. Each type derives unique properties and application scenarios due to differences in molecular structure.

 

Core Categories and Technical Characteristics

 

Polyethylene Film (PE)

 

Low-Density Polyethylene (LDPE): Outstanding flexibility and transparency, excellent moisture resistance, widely used in food packaging bags, agricultural mulch films, and thermal sealing layers of composite films.

High-Density Polyethylene (HDPE): High mechanical strength and chemical corrosion resistance, suitable for heavy packaging bags, anti-seepage geotextile films, and industrial containers.

Linear Low-Density Polyethylene (LLDPE): Excellent puncture and tear resistance, suitable for heavy logistics stretch films and agricultural greenhouse covering films.

 

Polypropylene Film (PP)

 

Cast Polypropylene (CPP): Uniform thickness and high transparency, mainly used as the inner layer material of composite packaging, suitable for oily food and retort packaging.

Biaxially Oriented Polypropylene (BOPP): After molecular orientation stretching, physical stability and gloss are significantly improved, widely used in food outer packaging printing layers and adhesive tape substrates.

 

Functional Films

 

Polyester Film (PET): High strength and excellent temperature resistance, serving as core materials for insulating layers of electronic components, lithium battery separators, and high-end food retort bags.

Nylon Film (PA): Extremely puncture-resistant and outstanding oxygen barrier performance, specially used for vacuum packaging of meat products and oil-resistant food packaging.

Aluminized Film: Vacuum aluminization process endows the substrate with light-shielding and UV blocking capabilities, replacing aluminum foil for outer packaging of puffed foods and pharmaceuticals.

High-Barrier Films: Such as PVA coated films and EVOH composite films, with excellent oxygen and moisture barrier properties, extending the shelf life of dairy products and fruit juices.

 

Vertical Differentiation of Application Scenarios

 

Food Packaging: PE cling film, CPP retort bags, and PA meat vacuum bags form a three-level protection system, balancing safety and shelf life.

Industry and Agriculture: HDPE anti-seepage films for water conservancy projects; LLDPE agricultural shed films to optimize crop microenvironment; PVC mulch films (restricted by environmental policies) are gradually replaced by degradable alternatives.

Electronics and Medical: PET insulating films ensure circuit safety; medical sterilization packaging relies on the sterile barrier properties of PA/PE composite films.

 

Industry Trends: Green and Intelligent Co-Evolution

 

Accelerated Degradable Substitution

Traditional PVC faces elimination due to plasticizer migration risks, and bio-based PLA and PBAT films are increasing in penetration in agricultural mulch films and food bags.

Upgrading of Composite Technology

Multi-layer co-extrusion technology promotes the development of single-material structures (such as all-PE packaging), balancing high barrier properties and recyclability to solve the separation problem of composite films.

Refined Functional Extension

Nano-coating technology imparts antibacterial and antistatic properties to films; intelligent temperature-controlled films achieve dynamic preservation in cold chain logistics.

 

Conclusion

The classification system of plastic films is a precise reflection of materials science and industrial needs—from molecular-level barriers protecting food safety to insulating barriers supporting electronic precision; from lightweight coverings improving agricultural efficiency to green substrates reconstructing the circular economy. In the future, with the deep integration of degradable technology and intelligent processes, this "thin yet powerful" material family will continue to break through the boundaries of performance and sustainability, providing efficient and responsible solutions for global industries.