Silicone straps are widely used in smartwatches and sports equipment due to their softness, skin-friendliness, and weather resistance. However, prolonged exposure to ultraviolet light and environmental factors can lead to aging phenomena such as yellowing, hardening, and cracking. Improving their anti-aging and UV resistance requires a comprehensive approach encompassing four dimensions: optimized material formulation, improved processing technology, enhanced surface treatment, and standardized use and maintenance. This aims to extend the strap's lifespan and maintain its aesthetic appeal.
Material formulation is fundamental to performance improvement. Adding UV absorbers to the silicone substrate is a direct and effective method. For example, benzotriazole and benzophenone compounds can absorb UV light and convert it into harmless heat energy, reducing the damage to the molecular chains caused by photochemical reactions. Simultaneously, fillers such as nano-silica and carbon black not only enhance mechanical properties but also shield UV light through scattering. Nano-zinc oxide, in particular, possesses photocatalytic properties, decomposing surface organic contaminants. Furthermore, choosing a platinum vulcanization system instead of traditional peroxide vulcanization can reduce oxidation reactions caused by residual peroxides during vulcanization, thereby improving resistance to yellowing.
Processing technology significantly impacts performance. During the vulcanization process, appropriately increasing the vulcanization temperature and extending the vulcanization time can increase the cross-linking density of silicone, forming a denser molecular network and enhancing its resistance to UV corrosion. The secondary vulcanization process, through high-temperature heat treatment, can remove unreacted low-molecular-weight substances from the surface, reducing porosity caused by later volatilization and improving overall stability. In the molding stage, controlling the uniformity of silicone strap thickness and surface smoothness is crucial; areas that are too thin or have a rough surface are more prone to accelerated aging due to stress concentration.
Surface coating technology provides a physical barrier for the silicone strap. Spraying UV-resistant coatings such as polyurethane and fluorocarbon resins can form a dense protective film, preventing UV rays from directly penetrating to the silicone substrate. Some coatings also have self-healing capabilities; when micro-cracks appear on the surface, the active ingredients in the coating can migrate to the damaged area and undergo a chemical reaction, achieving automatic repair. Nano-coating technology, by constructing nanoscale structures on the silicone surface, not only enhances hydrophobicity and reduces stain adhesion but also reduces UV transmittance through multiple scattering, making it particularly suitable for outdoor sports scenarios.
Material selection must be matched to the intended use case. Fluorosilicone rubber, due to the introduction of fluorine atoms into its molecular chain, possesses excellent weather resistance and chemical stability. Its UV resistance is significantly superior to ordinary silicone, making it suitable for products exposed to strong UV environments for extended periods. For light-colored or transparent straps, phenyl silicone rubber, by introducing a benzene ring structure, enhances molecular rigidity and effectively inhibits UV-induced yellowing. To balance cost and performance, anti-aging formulations, such as a composite system of antioxidants and UV absorbers, can be added to ordinary silicone to balance protection and economy.
Daily usage habits directly affect the lifespan of the strap. Avoiding prolonged exposure to sunlight is crucial, as UV-A and UV-B rays accelerate the breakage of silicone molecular chains, leading to surface embrittlement. After contact with sweat, wash promptly with a neutral detergent and dry with a soft cloth to prevent salt residue from causing electrochemical corrosion. Alternating between multiple straps reduces continuous tensile fatigue on a single strap, extending its elastic recovery period. Store in cool, humid environments, avoiding high temperatures and humidity. Humid conditions accelerate the moisture absorption and expansion of silicone, leading to a looser structure and reduced UV resistance.
Regular maintenance can slow down the aging process. Wipe the watch strap quarterly with a silicone-specific care product. The silicone component in the product forms a hydrophobic film on the surface, reducing contact with UV rays and oxygen. If the strap slightly hardens, apply a small amount of hand-applied oil to soften the surface, but avoid using solvent-based oils to prevent dissolving the silicone. Replace the strap immediately if it develops noticeable cracks or loses its elasticity to prevent breakage and watch loss.
Improving the anti-aging and UV resistance of silicone straps requires a comprehensive approach throughout their entire lifecycle, from material research and development to manufacturing and maintenance. Through formula optimization, process improvement, surface treatment, and scientific application, the service life of watch straps in complex environments can be significantly extended, meeting consumers' dual demands for product durability and aesthetics.
