Manufacturer's Overview of Shrink Film Classification and Characteristics

Shrink film is a versatile packaging material widely used for wrapping and bundling purposes. By utilizing heat shrink technology, shrink film ensures protection against contamination and damage. Based on different raw materials and manufacturing processes, shrink film can be classified into four main categories: PVC shrink film, PE shrink film, POF shrink film, and other shrink films.

Characteristics of PVC Shrink Film
PVC (Polyvinyl Chloride) shrink film is one of the earliest types of shrink film. It is produced through a secondary expansion process of polyvinyl chloride. Key features of PVC shrink film include high transparency, rigidity, and a low shrinkage temperature. While POF shrink film has gained significant market share in the display packaging field, PVC shrink film continues to dominate the shrink sleeve label market. This is due to its cost-effectiveness, high shrinkage rate, and ease of printing. However, its usage is increasingly restricted because harmful gases are generated during processing, posing environmental concerns.

Characteristics of PE Shrink Film
PE (Polyethylene) shrink film is another longstanding type of shrink film. Produced using the conventional blown film process, PE shrink film requires high processing temperatures, significantly above the melting point of polyethylene. Typically, low-density polyethylene with numerous long-chain structures is used to ensure adequate shrinkage. Advances in catalyst and polymerization technologies have led to the development of new metallocene polyethylene and linear low-density polyethylene, offering excellent mechanical properties and shrinkage rates. Consequently, the market now offers high-transparency, high-strength PE shrink films.

Characteristics of POF Shrink Film
POF (Polyolefin) shrink film has seen rapid development in recent years. Standard POF shrink film features a three-layer co-extruded structure, with a terpolymer polypropylene outer layer and a linear low-density polyethylene core layer. Similar to PVC shrink film, POF shrink film is produced using the double bubble method. The second film bubble's stability is challenging to maintain, demanding high-quality linear low-density polyethylene in the formulation. Cross-linked film represents a high-end product within the POF category. Unlike regular POF film, cross-linked film comprises a pure polyethylene structure and is produced using electron beam irradiation cross-linking technology. This process transforms the polymer chains from a linear to a network structure, enhancing the film's shrinkage and heat sealing properties, making it suitable for various packaging machinery and contents.

Conclusion
Shrink films are essential in modern packaging, offering protection and durability. Each type—PVC, PE, and POF—brings unique advantages suited to different applications. While environmental considerations are shifting the industry away from PVC, advancements in PE and POF technologies continue to enhance their performance and applicability in diverse packaging scenarios.