As a supplier of Medical PEVA Film, I've witnessed firsthand the importance of understanding how this material performs during long - term storage. In the medical field, the reliability and integrity of packaging materials are non - negotiable, and long - term storage can pose various challenges to the quality of Medical PEVA Film.
Physical and Chemical Properties of Medical PEVA Film
Medical PEVA Film is a blend of polyethylene (PE) and vinyl acetate (VA). This combination results in a material that is flexible, transparent, and has good moisture resistance. The vinyl acetate content can vary, typically ranging from 10% to 40%. A higher VA content generally leads to increased flexibility and transparency but may also affect the film's resistance to certain environmental factors during storage.
The physical properties of Medical PEVA Film, such as its tensile strength and elongation at break, are crucial for its performance. Tensile strength measures the maximum stress the film can withstand before breaking, while elongation at break indicates how much the film can stretch before failure. These properties can change over time during storage, especially if the film is exposed to unfavorable conditions.
Chemically, the PEVA structure can be affected by factors like oxidation. Oxidation occurs when the film comes into contact with oxygen, which can break down the polymer chains. This process can lead to a decrease in the film's mechanical properties, such as becoming brittle and losing its flexibility. UV light can also accelerate oxidation, so proper storage to prevent light exposure is essential.
Impact of Storage Conditions on Medical PEVA Film
Temperature
Temperature is one of the most significant factors affecting the long - term storage of Medical PEVA Film. High temperatures can cause the film to soften and lose its shape. If stored at temperatures above its melting point range (which can vary depending on the VA content), the film may even fuse together, making it unusable. On the other hand, extremely low temperatures can make the film brittle. For most Medical PEVA Films, a storage temperature between 10°C and 30°C is recommended to maintain its physical properties.
Humidity
Humidity can also have a profound impact on Medical PEVA Film. High humidity levels can lead to moisture absorption by the film. While PEVA has some moisture resistance, excessive moisture can cause swelling and a decrease in the film's mechanical strength. It can also promote the growth of mold and bacteria, which is a serious concern in the medical field. To prevent these issues, the relative humidity in the storage environment should be kept between 40% and 60%.
Light Exposure
As mentioned earlier, UV light can accelerate the oxidation process of Medical PEVA Film. Prolonged exposure to sunlight or other sources of UV light can cause the film to yellow, become brittle, and lose its transparency. Therefore, the film should be stored in a dark place or in opaque packaging to protect it from light.
Testing the Performance of Medical PEVA Film during Long - Term Storage
To ensure the quality of Medical PEVA Film during long - term storage, various tests can be conducted.
Physical Property Testing
Periodic testing of the film's tensile strength and elongation at break can provide insights into how its mechanical properties are changing over time. Samples can be taken from the stored film and tested using a universal testing machine. If there is a significant decrease in these properties, it may indicate that the storage conditions need to be adjusted.
Chemical Analysis
Chemical analysis techniques, such as Fourier - transform infrared spectroscopy (FTIR), can be used to detect any chemical changes in the film. FTIR can identify the presence of oxidation products or other chemical degradation products. This information can help in understanding the extent of chemical changes and taking appropriate measures to prevent further degradation.
Microbiological Testing
Since Medical PEVA Film is used in the medical field, microbiological testing is essential. Samples of the film can be tested for the presence of bacteria, fungi, and other microorganisms. If any microbial growth is detected, it may be a sign of improper storage conditions, such as high humidity or contamination during handling.
Case Studies of Long - Term Storage of Medical PEVA Film
In one case, a medical facility stored a large quantity of Medical PEVA Film in a warehouse with poor temperature and humidity control. Over a period of six months, the film started to show signs of degradation. The film became brittle, and its transparency decreased. Physical property testing revealed a significant decrease in tensile strength and elongation at break. Chemical analysis showed the presence of oxidation products, indicating that the film had been exposed to oxygen and possibly UV light. Microbiological testing also detected the presence of mold, which was likely due to the high humidity in the warehouse.
In contrast, another medical facility stored their Medical PEVA Film in a climate - controlled environment with proper temperature, humidity, and light protection. After two years of storage, the film maintained its physical and chemical properties. Physical property testing showed only minimal changes in tensile strength and elongation at break, and chemical analysis did not detect any significant oxidation products. Microbiological testing was also negative for microbial growth.
Comparison with Other Films in Long - Term Storage
When comparing Medical PEVA Film with other films used in the medical field, such as polyethylene (PE) film and polyvinyl chloride (PVC) film, it has some unique advantages and disadvantages in long - term storage.
PE film is known for its excellent moisture resistance and chemical stability. However, it is less flexible than PEVA film, which can be a drawback in some medical applications. During long - term storage, PE film is less likely to be affected by oxidation due to its simple chemical structure.
PVC film is more rigid and has good mechanical properties. However, it can release plasticizers over time, which can cause environmental and health concerns. In long - term storage, PVC film may be more prone to degradation if exposed to high temperatures or certain chemicals.
Medical PEVA Film strikes a balance between flexibility and chemical stability. It has better flexibility than PE film and is less likely to release harmful substances compared to PVC film. However, it requires more careful storage conditions to prevent oxidation and microbial growth.
Best Practices for Long - Term Storage of Medical PEVA Film
Based on the above analysis, the following best practices can be recommended for the long - term storage of Medical PEVA Film:
- Temperature and Humidity Control: Maintain a storage temperature between 10°C and 30°C and a relative humidity between 40% and 60%. Use climate - controlled storage facilities if possible.
- Light Protection: Store the film in a dark place or use opaque packaging to prevent UV light exposure.
- Proper Handling: Ensure that the film is handled with clean gloves to prevent contamination. Avoid rough handling that can cause scratches or damage to the film.
- Regular Inspection and Testing: Conduct regular physical, chemical, and microbiological testing of the stored film to monitor its quality.
Conclusion
In conclusion, the performance of Medical PEVA Film during long - term storage depends on various factors, including storage conditions, physical and chemical properties, and proper handling. By understanding these factors and following best practices for storage, the quality of the film can be maintained over an extended period. If you are interested in learning more about Medical PEVA Film or other related products such as PEVA Shower Curtain Film, please feel free to contact us for procurement and further discussions.
References
- ASTM International. ASTM D882 - 18: Standard Test Method for Tensile Properties of Thin Plastic Sheeting.
- ISO 11137 - 1:2015: Sterilization of health care products - Radiation - Part 1: Requirements for development, validation, and routine control of a sterilization process for medical devices.
- European Pharmacopoeia 10.0. General chapter 5.1.4. Microbiological quality of non - sterile pharmaceutical preparations and substances for pharmaceutical use.