Bamboo fiber stretch shirt fabric holds a unique position in the clothing industry due to its natural antibacterial properties, moisture absorption and breathability, and good elasticity. However, its UV protection performance is limited by the fiber structure, requiring optimization with additives to meet the needs of outdoor or high-UV environments. The mechanism of these additives is to enhance the bamboo fiber stretch shirt fabric's ability to reflect, scatter, or absorb UV rays through physical or chemical means, while simultaneously maintaining the natural properties of bamboo fiber and wearing comfort.
Nano zinc oxide (ZnO) is a commonly used additive to improve UV protection. Its electron-hole pairs in its crystal structure can reflect or scatter UV rays, forming a physical barrier. Applying nano ZnO dispersions to the surface of bamboo fibers through impregnation, coating, or spraying processes can form a uniform nanofilm layer between the fibers. This film layer not only reflects UV rays but also decomposes some organic pollutants through photocatalysis, extending the lifespan of the bamboo fiber stretch shirt fabric. For example, treating bamboo fiber stretch shirt fabric with a ZnO dispersion with an average particle size of approximately 50 nanometers can significantly improve its UV shielding effect while maintaining its elasticity.
Titanium dioxide (TiO₂) is another highly efficient ultraviolet (UV) absorber, especially effective against UVA and UVB. Combining TiO₂ with nano-ZnO provides full-spectrum UV protection. The composite additive is introduced into the bamboo fiber via sol-gel or blend spinning techniques, forming stable chemical bonds and preventing performance degradation due to washing or friction. For example, adding TiO₂/ZnO composite particles during the blending of bamboo fiber and spandex allows the bamboo fiber stretch shirt fabric to maintain over 90% UV shielding even after multiple washes.
Sodium copper chlorophyllin, as a natural UV absorber, exhibits excellent affinity with bamboo fiber. Its conjugated double bond system absorbs UV energy and converts high-energy UV radiation into low-energy heat through electronic transitions. After encapsulating sodium copper chlorophyllin extract using microencapsulation technology, it is applied to bamboo fiber stretch shirt fabric via padding or coating processes. This preserves the natural feel of bamboo fiber while enhancing its UV resistance. Microencapsulation also allows for the slow release of sodium copper chlorophyllin, extending the protective effect.
Organic UV absorbers, such as benzotriazoles and benzophenones, can be fixed to the bamboo fiber surface through chemical grafting or physical adsorption. These additives contain chromophores in their molecular structure, which absorb specific wavelengths of UV light and undergo intramolecular electron transfer, thereby reducing UV damage to the fiber. For example, finishing bamboo fiber with benzophenones can form a transparent protective film on the surface of bamboo fiber stretch shirt fabric, reducing UV transmittance to below 1%. However, it should be noted that some organic absorbers may experience performance degradation after long-term use due to insufficient photostability, requiring structural modification to improve their weather resistance.
Rare earth element additives, such as oxides of cerium (Ce) and lanthanum (La), can be introduced into the bamboo fiber structure through doping processes. Rare earth elements possess a unique 4f electron layer structure, enabling them to absorb high-energy ultraviolet radiation and undergo f-f electron transitions, converting energy into harmless heat. For example, loading cerium oxide nanoparticles onto the surface of bamboo fiber using a sol-gel method allows bamboo fiber stretch shirt fabric to maintain color stability under ultraviolet radiation while enhancing its anti-aging properties. The amount of rare earth additives used must be strictly controlled; excessive amounts may cause the bamboo fiber stretch shirt fabric to yellowish or become stiff.
The synergistic effect of additives is key to improving UV resistance. For instance, combining nano-ZnO with sodium copper chlorophyllin can simultaneously provide both physical shielding and chemical absorption, enabling the bamboo fiber stretch shirt fabric to achieve high-efficiency protection across a wide wavelength range. Furthermore, adding a small amount of silane coupling agent can enhance the bonding force between the additive and bamboo fiber, improving wash resistance; adding fabric softener can neutralize the stiffness of the additive, maintaining the elasticity and comfort of the bamboo fiber stretch shirt fabric.
Improving the UV resistance of bamboo fiber stretch shirt fabric requires comprehensive consideration of additive type, process parameters, and fiber characteristics. The combined use of nano-metal oxides, natural extracts, and organic compounds, along with advanced processes such as microcapsules and sol-gels, can achieve highly efficient and long-lasting UV protection while maintaining the natural advantages of bamboo fiber stretch shirt fabric. In the future, with the development of green chemistry and nanotechnology, environmentally friendly and multifunctional UV-resistant additives will open up even broader applications for bamboo fiber stretch shirt fabric.
