Needle punched nonwovens are widely used in various industries, including Needle Punched for Sofa Mattress, Needle Punched for Automotive Interior, and Needle Punched Nonwoven For Furniture Decoration. However, one of the challenges faced by needle punched nonwoven products is their relatively poor anti-UV property, which can lead to degradation, color fading, and reduced physical performance over time when exposed to sunlight. As a needle punched nonwoven supplier, I understand the importance of enhancing the anti-UV property of our products to meet the diverse needs of our customers. In this blog, I will share some effective ways to improve the anti-UV property of needle punched nonwovens.
Understanding the Mechanism of UV Damage
Before delving into the improvement methods, it is essential to understand how UV radiation damages needle punched nonwovens. UV rays, especially UV-A (320 - 400 nm) and UV-B (280 - 320 nm), can penetrate the surface of nonwoven materials and cause chemical reactions within the polymer chains. These reactions can break the chemical bonds, leading to chain scission, cross - linking, and oxidation. As a result, the nonwoven may lose its strength, become brittle, and change color.
Selection of UV - Resistant Fibers
One of the most fundamental ways to improve the anti-UV property of needle punched nonwovens is to select fibers with inherent UV resistance. Some synthetic fibers, such as polyester and polypropylene, have better UV resistance compared to natural fibers like cotton and wool.
Polyester
Polyester fibers are known for their excellent dimensional stability and relatively good UV resistance. The aromatic structure of polyester provides some protection against UV radiation. However, to further enhance its anti-UV performance, it can be modified during the fiber - spinning process. For example, adding UV - absorbing additives to the polyester polymer melt before extrusion can significantly improve its ability to block UV rays.
Polypropylene
Polypropylene has a high strength - to - weight ratio and is widely used in needle punched nonwovens. Although it is more prone to UV degradation than polyester, it can be treated with stabilizers and UV absorbers. Hindered amine light stabilizers (HALS) are commonly used in polypropylene to scavenge free radicals generated by UV radiation, thereby preventing chain scission and oxidation.
Incorporation of UV - Absorbing Additives
Another effective approach is to incorporate UV - absorbing additives into the needle punched nonwovens during the manufacturing process. These additives work by absorbing UV radiation and converting it into heat, which is then dissipated.
Organic UV Absorbers
Organic UV absorbers, such as benzophenones and benzotriazoles, are commonly used in the nonwoven industry. Benzophenones can absorb UV rays in the 280 - 350 nm range, while benzotriazoles have a broader absorption spectrum, covering both UV - A and UV - B. These additives can be added to the fiber matrix during the spinning process or applied as a coating on the surface of the nonwoven after needle punching.
Inorganic UV Absorbers
Inorganic UV absorbers, such as titanium dioxide (TiO₂) and zinc oxide (ZnO), are also popular choices. TiO₂ and ZnO have high refractive indices and can scatter and absorb UV radiation effectively. They are non - toxic, stable, and can provide long - term UV protection. These inorganic particles can be incorporated into the nonwoven during the fiber - forming process or applied as a surface treatment. For example, a fine dispersion of TiO₂ nanoparticles can be sprayed onto the nonwoven surface, creating a thin layer that blocks UV rays.
Surface Coating
Applying a UV - resistant coating on the surface of needle punched nonwovens is an effective way to enhance their anti-UV property. The coating acts as a barrier, preventing UV rays from reaching the underlying fibers.
Polymer - Based Coatings
Polymer - based coatings, such as acrylic and polyurethane coatings, can be formulated with UV - absorbing additives. Acrylic coatings are known for their good adhesion, flexibility, and weather resistance. They can be applied to the nonwoven surface by methods such as dipping, spraying, or knife - coating. Polyurethane coatings, on the other hand, offer excellent abrasion resistance and can provide a durable UV - protective layer.
Sol - Gel Coatings
Sol - gel coatings are another option for improving the anti-UV property of nonwovens. These coatings are formed by the hydrolysis and condensation of metal alkoxides, such as tetraethyl orthosilicate (TEOS). The sol - gel coating can be doped with UV - absorbing agents, such as organic dyes or inorganic nanoparticles. The advantage of sol - gel coatings is their ability to form a uniform and porous layer on the nonwoven surface, which can effectively block UV radiation while maintaining the breathability of the nonwoven.
Post - Treatment Processes
In addition to the above methods, some post - treatment processes can also enhance the anti-UV property of needle punched nonwovens.
Heat Treatment
Heat treatment can improve the crystallinity of the fibers in the nonwoven, which in turn can enhance their UV resistance. By heating the nonwoven to a specific temperature and holding it for a certain period, the polymer chains can rearrange into a more ordered structure, making it more difficult for UV rays to penetrate and cause damage.
Plasma Treatment
Plasma treatment is a surface - modification technique that can improve the adhesion of UV - protective coatings or additives to the nonwoven surface. The plasma can activate the surface of the nonwoven fibers, increasing their surface energy and allowing better wetting and bonding of the subsequent treatments. This can lead to a more effective and durable anti-UV protection.
Quality Control and Testing
After implementing the methods to improve the anti-UV property of needle punched nonwovens, it is crucial to conduct quality control and testing. There are several standard tests available to evaluate the anti-UV performance of nonwovens, such as the Ultraviolet Protection Factor (UPF) test and the Xenon - arc lamp accelerated aging test.
UPF Test
The UPF test measures the effectiveness of a fabric in blocking UV radiation. It indicates the ratio of the amount of UV radiation that can penetrate the fabric to the amount of UV radiation that is incident on the fabric. A higher UPF value means better UV protection.
Xenon - Arc Lamp Accelerated Aging Test
In this test, the nonwoven sample is exposed to a xenon - arc lamp, which simulates natural sunlight. The sample is subjected to a specific amount of UV radiation for a certain period, and then its physical and chemical properties are evaluated. This test can quickly assess the long - term anti-UV performance of the nonwoven under accelerated aging conditions.
Conclusion
Improving the anti-UV property of needle punched nonwovens is a multi - faceted task that involves fiber selection, additive incorporation, surface coating, and post - treatment processes. By understanding the mechanism of UV damage and implementing these effective methods, we can produce needle punched nonwovens with enhanced UV resistance, meeting the high - quality requirements of various applications, including sofa mattresses, automotive interiors, and furniture decoration.
As a needle punched nonwoven supplier, we are committed to providing our customers with high - performance products. If you are interested in our needle punched nonwovens with improved anti-UV properties or have any questions regarding UV protection, please feel free to contact us for further discussion and potential procurement. We look forward to establishing long - term partnerships with you.
References
- Zweig, A., & Domaszkiewicz, W. (2017). Influence of UV radiation on non - woven fabrics. Fibres & Textiles in Eastern Europe, 25(2(121)), 83 - 88.
- Ge, J., & Yang, G. (2016). A review on the development of ultraviolet protection of textiles. Journal of Industrial and Engineering Chemistry, 38, 279 - 289.
- Wypych, G. (2016). Handbook of UV Degradation and Stabilization. ChemTec Publishing.