PET shrink film is a commonly used packaging material known for its high transparency, good shrinkability, and strong abrasion resistance. However, in practical use, PET shrink film sometimes whitens after heat shrinking, affecting the appearance and aesthetics of the product.
Causes of PET Shrink Film Whitening
The main reasons for PET shrink film whitening are as follows:
- Factors of PET Material Itself: PET material contains small amounts of moisture and impurities. During heat shrinking, these can precipitate out, causing the PET shrink film to whiten.
- Improper Heat Shrinking Process: Excessive heat shrinking temperature or duration can cause PET material decomposition, resulting in white substances and thus whitening of the PET shrink film.
- Surface Contamination of Shrink Film: If the surface of PET shrink film is contaminated with oils, dust, or other foreign substances, these can react with the PET material during heat shrinking, leading to whitening.
Solutions to PET Shrink Film Whitening
To address the issue of PET shrink film whitening, the following measures can be taken:
- Choose High-Quality PET Material: When selecting PET material, choose types with lower moisture and impurity content.
- Adjust Heating Temperature: Attempt to lower the heating temperature, especially initially. Test different temperatures gradually to find suitable heating conditions that prevent whitening.
- Keep Shrink Film Surface Clean: Before using PET shrink film, thoroughly clean its surface to prevent contamination.
- Consider Changing Shrink Film Brand or Type: Consider switching to another brand or type of shrink film. Specific materials or designs may be more suitable for certain heating conditions, avoiding whitening issues.
- If PET shrink film still whitens after adjusting furnace temperature, transmission speed, and working in conjunction with air circulation, suggest changing heat shrink equipment.
Here are some specific suggestions
- Request material testing reports from suppliers when selecting PET materials to understand their moisture and impurity levels.
- Before using the heat shrink machine, carefully read the operating manual to understand its setup methods.
- During the heat shrinking process, closely observe changes in PET shrink film and adjust heating temperature or time promptly.
- If the surface of PET shrink film is contaminated with foreign substances, promptly wipe it clean with a cleaner.
Preventing PET Shrink Film Whitening
To prevent PET shrink film from whitening, pay attention to the following:
- Store PET shrink film in a cool, dry place to avoid direct sunlight and high-temperature, high-humidity environments.
- Ensure PET shrink film is thoroughly dried before use.
- Wear gloves when handling PET shrink film to prevent sweat or grease from hands contaminating the film surface.
Conclusion
Whitening of PET shrink film is a common issue during its use. By implementing the above measures, you can effectively solve the problem of PET shrink film whitening, thereby enhancing its quality and aesthetic appeal.
I hope these suggestions are helpful to you! If you have further questions or need additional assistance, please feel free to contact us anytime.