As a dedicated supplier of Surlyn skin film, I understand the critical importance of quality control in ensuring that our product meets the highest standards and customer expectations. Surlyn skin film, known for its excellent clarity, toughness, and heat-sealing properties, is widely used in various industries such as food packaging, electronics, and medical devices. In this blog post, I will discuss the key quality control indicators for Surlyn skin film to help our customers better understand the quality assurance process and make informed decisions when purchasing our products.
1. Thickness Uniformity
Thickness uniformity is one of the most fundamental quality control indicators for Surlyn skin film. The thickness of the film directly affects its mechanical properties, barrier performance, and heat-sealing characteristics. A film with inconsistent thickness may lead to uneven sealing, poor appearance, and reduced product performance.
To ensure thickness uniformity, we use advanced extrusion equipment and precision control systems. During the production process, we continuously monitor the thickness of the film at multiple points using online thickness gauges. These gauges provide real-time feedback, allowing us to make immediate adjustments to the extrusion parameters if any deviations are detected. Our target is to maintain a thickness variation within ± 5% across the entire width and length of the film.
2. Tensile Strength and Elongation
Tensile strength and elongation are important mechanical properties that measure the film's ability to withstand stretching and deformation. High tensile strength ensures that the film can resist tearing during handling, packaging, and transportation, while sufficient elongation allows the film to conform to the shape of the packaged product without breaking.
We conduct regular tensile tests on our Surlyn skin film samples using a universal testing machine. The samples are cut into standard rectangular strips and pulled at a constant speed until they break. The maximum force applied during the test is recorded as the tensile strength, and the percentage increase in length at the break point is defined as the elongation. Our Surlyn skin film typically has a tensile strength of 20 - 30 MPa and an elongation at break of 300 - 500%.
3. Heat-Sealing Strength
Heat-sealing strength is a crucial quality control indicator for Surlyn skin film, especially in packaging applications. A strong heat seal ensures that the package remains intact during storage and transportation, preventing the entry of moisture, oxygen, and other contaminants.
We use a heat-sealing tester to measure the heat-sealing strength of our film. Two layers of film are placed together and sealed under controlled temperature, pressure, and time conditions. After cooling, the sealed samples are pulled apart using the universal testing machine, and the force required to separate the seals is recorded. Our target heat-sealing strength is typically 5 - 10 N/15mm, depending on the specific application requirements.
4. Clarity and Haze
Clarity and haze are optical properties that affect the visual appearance of the Surlyn skin film. High clarity allows consumers to clearly see the packaged product, enhancing its marketability, while low haze ensures a smooth and transparent surface.
We use a haze meter to measure the clarity and haze of our film. The haze is defined as the percentage of light that is scattered when passing through the film, while the clarity is the percentage of light that passes through the film without being scattered. Our Surlyn skin film typically has a haze value of less than 2% and a clarity value of greater than 90%, providing excellent visual appeal.
5. Moisture Vapor Transmission Rate (MVTR)
Moisture vapor transmission rate (MVTR) is an important quality control indicator for Surlyn skin film, especially in food and pharmaceutical packaging applications. A low MVTR ensures that the packaged product remains dry and fresh by preventing the entry of moisture.
We use a moisture permeability tester to measure the MVTR of our film. A sample of the film is placed in a test cell, and a controlled humidity gradient is established across the film. The amount of moisture that passes through the film over a specific period of time is measured, and the MVTR is calculated. Our Surlyn skin film typically has an MVTR of less than 1 g/m²/day at 38°C and 90% relative humidity, providing excellent moisture barrier properties.
6. Oxygen Transmission Rate (OTR)
Oxygen transmission rate (OTR) is another important quality control indicator for Surlyn skin film, especially in food and beverage packaging applications. A low OTR ensures that the packaged product remains fresh and free from oxidation by preventing the entry of oxygen.
We use an oxygen permeability tester to measure the OTR of our film. A sample of the film is placed in a test cell, and a controlled oxygen gradient is established across the film. The amount of oxygen that passes through the film over a specific period of time is measured, and the OTR is calculated. Our Surlyn skin film typically has an OTR of less than 10 cm³/m²/day/atm at 23°C and 0% relative humidity, providing excellent oxygen barrier properties.
7. Chemical Resistance
Surlyn skin film may come into contact with various chemicals during its use, such as cleaning agents, solvents, and food additives. Therefore, it is important to ensure that the film has good chemical resistance to prevent degradation and maintain its performance.
We conduct chemical resistance tests on our Surlyn skin film samples by immersing them in various chemicals for a specific period of time. After immersion, the samples are visually inspected for any signs of swelling, discoloration, or degradation. We also measure the changes in the mechanical properties of the samples, such as tensile strength and elongation, to evaluate the effect of the chemicals on the film. Our Surlyn skin film has good chemical resistance to most common chemicals, including acids, bases, and solvents.
8. Surface Roughness
Surface roughness is an important quality control indicator for Surlyn skin film, especially in applications where the film needs to be printed or laminated. A smooth surface ensures good ink adhesion and lamination quality, while a rough surface may cause printing defects and poor lamination bond strength.
We use a surface profilometer to measure the surface roughness of our film. The profilometer scans the surface of the film and records the height variations along a specific line. The average roughness (Ra) and the maximum roughness (Rz) are calculated based on the measured data. Our target surface roughness for printing and lamination applications is typically Ra < 0.5 µm and Rz < 5 µm.
Conclusion
In conclusion, quality control is of utmost importance in the production of Surlyn skin film. By monitoring and controlling these key quality indicators, we ensure that our Surlyn skin film meets the highest standards and provides our customers with a reliable and high-performance packaging solution.
If you are interested in our Surlyn Skin Film, Dupont Surlyn Film, or Dupont Surlyn Skin Packaging Film, please feel free to contact us for more information and to discuss your specific requirements. We look forward to the opportunity to work with you and provide you with the best quality Surlyn skin film products.
References
- ASTM International. (2023). ASTM standards for plastic films.
- DuPont. (2023). Technical information on Surlyn resins and films.
- Packaging Machinery Manufacturers Institute (PMMI). (2023). Best practices for packaging film quality control.