Today, stretch film is widely used in China's industrial production. As a crucial packaging material, stretch film plays an essential role in protecting goods. It is no exaggeration to say that if stretch film cannot reliably protect the packaged goods, it loses its value as a packaging material and fails to be selected for use.


 

Diverse Protective Functions of Stretch Film

Stretch film offers a variety of protective functions for goods. Different products and packaging methods have varying requirements for the protective capabilities of stretch film. Below are the main protective features that demonstrate the excellent protection provided by stretch film:

1. Reliable Mechanical Protection

Mechanical protection primarily includes preventing damage and contamination caused by packaging breaches during transportation and storage. Key indicators reflecting the mechanical protection function of stretch film are its mechanical strengths, such as tensile strength, tear strength, impact resistance, and puncture resistance. The higher the strength values, the better the protective effect, effectively preventing leakage of goods inside the package or the entry of foreign objects from outside.

2. Good Adhesion Strength

To ensure that stretch film securely holds the goods, good adhesion strength is essential. Insufficient adhesion strength can lead to gaps in the stretch film, causing packaging failure and compromising the stability and safety of the goods. Ordinary bi-axially oriented polypropylene (BOPP) film has good mechanical strength but poor adhesion properties, making it generally unsuitable for bag making. For applications requiring bag formation, a composite BOPP film with a heat-sealing layer (CPP) should be selected, as it offers superior adhesion. The adhesive performance of stretch film is typically measured by adhesion strength (N/15mm), with higher values indicating better adhesion.

3. Other Important Features

In addition to mechanical protection and adhesion strength, stretch film also provides isolation and shading functions crucial for protecting goods.

• Isolation Function: Stretch film can block oxygen, carbon dioxide, nitrogen, and other non-polar gases, as well as moisture and other substances. This is particularly important for preventing oxidation, spoilage, and the spread of odors within the packaged goods.

• Thermal Insulation Function: For many products, especially food items, the thermal insulation properties of stretch film are key to ensuring long-term storage quality. Different products have varying requirements for thermal insulation, and stretch film should be selected accordingly to meet specific needs.

• Shading Function: Certain goods are highly sensitive to light, particularly ultraviolet (UV) light, which can cause photo-oxidation, leading to discoloration and degradation. The shading performance of stretch film is assessed by measuring its light transmittance at specific wavelengths. Stretch films with low light transmittance have strong shading effects, effectively protecting light-sensitive goods.

Conclusion

Stretch film plays a multifaceted role in packaging, providing mechanical protection, secure adhesion, isolation, and shading. Understanding and selecting stretch film with excellent performance can significantly enhance packaging quality, ensuring the safety and stability of goods during transportation and storage. By effectively utilizing the various protective functions of stretch film, businesses can improve packaging efficiency and product quality, meeting the diverse needs of different products and packaging methods.