Stretch film frequently encounters varying temperature fluctuations during scenarios such as warehouse storage, cross-border transportation, and workshop processing. Its high-temperature tolerance limit and thermal stability directly impact packaging integrity and cargo safety. Wrap films made from different materials exhibit significant variations in their temperature tolerance ranges, high-temperature performance characteristics, and suitable applications due to differences in molecular structure and manufacturing processes. Currently, mainstream polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), and biodegradable wrap films each emphasize distinct aspects of high-temperature resistance. The following provides a comprehensive analysis based on specific temperature parameters, performance changes, and practical application scenarios.

PE stretch film, as the dominant category accounting for over 80% of the market share, exhibits high-temperature resistance significantly influenced by density and processing techniques. It is generally suited for low-to-medium temperature applications, covering most general packaging needs. Linear low-density polyethylene (LLDPE) stretch film sees the widest application. Leveraging the advantages of its three-layer co-extrusion process, it maintains continuous high-temperature resistance up to 60-80°C. It can withstand short-term peak temperatures of 80-90°C. However, exposure above 90°C causes rapid softening, with tensile strength plummeting by over 30%, potentially leading to adhesion to goods and surface contamination. This material is ideal for ambient storage and short-distance transport of hardware components, cardboard stacks, and similar applications, making it the preferred choice for industrial packaging. Low-density polyethylene (LDPE) stretch film exhibits slightly weaker thermal stability, with a continuous use limit of only 50-70°C. It tends to deform and lose transparency at elevated temperatures, making it suitable only for ambient storage packaging of lightweight daily goods, clothing, and similar items. High-density polyethylene (HDPE) stretch film, due to its high crystallinity, offers superior heat resistance compared to the previous two types. It can withstand continuous use at temperatures of 80-100°C and short-term exposure up to 110°C. It maintains a certain level of rigidity and puncture resistance even at high temperatures, making it suitable for medium-temperature logistics scenarios requiring protective strength, such as building materials and mechanical components.

PVC stretch film exhibits poor high-temperature resistance, being a typical low-temperature compatible material. Its application scenarios are gradually shrinking due to environmental policy restrictions. Its safe continuous operating temperature range is limited to -5°C to 60°C. When ambient temperatures exceed 65°C, not only does it suffer packaging failures such as softening, adhesion, and tensile rupture, but it may also release harmful substances like plasticizers, posing safety hazards. At temperatures above 80°C, it rapidly degrades and deforms, completely losing its protective function. Due to these characteristics, PVC stretch film is only suitable for ambient-temperature bundling applications without high-temperature exposure requirements, such as wire and cable packaging or small retail goods. It has been fully replaced in sectors demanding safety and temperature stability, including food and pharmaceutical industries.

PP stretch film stands out as the most heat-resistant category among mainstream materials. Leveraging the high crystallinity of polypropylene molecules, it delivers exceptional thermal stability and high-temperature conformability. It can withstand continuous temperatures of 100-120°C and short-term exposure to 130-140°C. Even in high-temperature environments, it maintains good toughness, transparency, and tensile strength, resisting softening and adhesion with a performance degradation rate below 15%. Additionally, PP stretch film exhibits strong weather resistance, making it suitable for outdoor storage with significant temperature fluctuations or medium-temperature processing and logistics scenarios. It is particularly well-suited for applications with explicit high-temperature requirements, such as high-temperature packaging of electronic products, post-processing food items (e.g., freshly baked pastries, cooked food transfers), and temporary packaging of automotive components after drying. Note that its low-temperature performance is weaker; it becomes brittle and prone to cracking below -10°C, rendering it unsuitable for outdoor transportation in cold regions.

The high-temperature resistance of biodegradable stretch film varies significantly depending on the substrate type, with overall performance inferior to traditional plastic materials. Its applications are primarily confined to ambient temperature scenarios where environmental sensitivity is a priority. PLA (polylactic acid) biodegradable stretch film exhibits the poorest thermal stability, with a maximum continuous operating temperature of only 50-60°C. Exposure above 70°C causes rapid softening, degradation, and loss of tensile strength, rendering it unsuitable for medium-to-high temperature applications. It is primarily used for ambient freshness packaging of vegetables, fruits, and fresh foods, as well as short-distance cold chain auxiliary packaging. Bio-based PE biodegradable stretch film, optimized through modification processes, exhibits slightly improved heat resistance with a continuous operating temperature of 60-80°C, approaching conventional LLDPE film levels. It can be used for eco-friendly packaging of room-temperature daily necessities and agricultural products. However, it accelerates degradation at high temperatures, reducing its service life to 60%-70% of conventional film. Starch-based biodegradable stretch film exhibits the poorest high-temperature resistance, deforming or breaking at temperatures exceeding 50°C. It is suitable only for packaging lightweight goods in low-temperature, short-distance transportation.

In summary, the high-temperature resistance of stretch wrap must be precisely matched to its application scenario: PP film is suitable for medium-to-high temperature processing and logistics environments; HDPE film is ideal for medium-temperature protection scenarios; LLDPE and LDPE films cover general packaging at ambient and low temperatures; while PVC film and most biodegradable films are only applicable at ambient temperatures. When making actual selections, beyond considering continuous operating temperatures and short-term high-temperature peaks, comprehensive evaluation must incorporate cargo characteristics, storage duration, and environmental requirements to prevent packaging failure due to temperature mismatches. Looking ahead, as modification technologies and biodegradable material R&D advance, enhancing high-temperature resistance while balancing environmental sustainability and practicality will become the core direction for overcoming application limitations in biodegradable stretch wrap.