POF vs. PEF Shrink Film: A Concise Comparison of Molecular Structure, Manufacturing Process, and Performance
Shrink Films have become essential materials in modern packaging industry due to their efficiency in packaging, product protection, and appearance enhancement. Among various types, POF Shrink Film is widely recognized and extensively used in the industry for its stable shrinkage rate, high toughness, and good transparency. Meanwhile, PEF Shrink Film, as an emerging packaging material, demonstrates promising market potential with its eco-friendly sustainability and high performance. The two exhibit significant differences in molecular structure, production processes, and performance characteristics. This article provides analysis of their core features, offering valuable insights for procurement professionals and businesses.
1.Differences in Molecular Structure
POF is a multilayer co-extruded polyolefin shrink film, typically composed of linear low-density polyethylene (LLDPE) as the middle layer and copolymer polypropylene (PP) as the inner and outer layers. It is produced through processes such as extrusion, molding, and bubble inflation. This composite structure gives Pof Film with superior physical and processing properties—PP enhances strength and rigidity, while PE improves flexibility and heat-sealing performance.
PEF is a mono material, biaxially stretched polyolefin shrink film primarily made from LLDPE. Its mono material structure provides significant advantages in recycling and reuse, aligning with the growing trend toward sustainable packaging solutions.
2.Differences in Manufacturing Processes
Most commercially available POF films are produced using three- or five-layer co-extrusion with a downward and watercooled blown process. Additionally, Cross-linked POF Film—a special type—are manufactured using radiation or chemical cross-linking technology. This process alters the molecular structure, significantly enhancing heat resistance and mechanical strength.
PEF film is produced by a five-layer co-extrusion double bubble method, eliminating the need for physical cross-linking. This process ensures uniform shrinkage and optimal performance through precise control of extrusion speed, temperature, and cooling rates during production.
3.Performance Comparison
Due to differences in molecular structure and manufacturing techniques, POF and PEF Shrink Film exhibit distinct performance characteristics.
Recyclability:
PEF Film meets mono material polyethylene standards, making it easy to separate and recycle, thereby supporting environmental sustainability. In contrast, POF's composite structure complicates material separation during recycling, posing greater challenges.
Flexibility and Transparency:
PEF Film offers outstanding flexibility and high transparency, making it ideal for industries such as electronics, cosmetics, and handicrafts, where aesthetic appeal and eco-friendliness are prioritized. POF film, on the other hand, is known for its toughness and consistent shrinkage, making it suitable for products requiring robust mechanical protection but with lower recycling demands.
Shrinkage temperature:
Cross-linked POF Film exhibits enhanced heat resistance due to physical cross-linking, ensuring stable performance under high temperatures. Meanwhile, PEF Film can shrink and form within the temperature range of 135℃-145℃ (compared to POF’s typical >145°C), potentially reducing production costs for manufacturers.
POF and PEF Shrink Film differ significantly in molecular structure, production processes, and performance. Businesses should consider product requirements, market demands, and environmental factors when selecting packaging materials. For general-purpose packaging, conventional POF Films remain a cost-effective and reliable choice due to their mature technology. For high-performance applications, Cross-linked POF Film may be preferable. As technology advances and environmental awareness grows, PEF Shrink Film is poised to play an increasingly vital role in the future of sustainable packaging.