The material properties of UV-resistant PVC baseball are mainly reflected in the following aspects:
1. Uv resistance
Molecular structure characteristics: There are a large number of chlorine atoms in the PVC (polyvinyl chloride) molecular chain, the intermolecular forces are relatively weak, and the chlorine atoms on the tertiary carbon atoms are highly active. Under the influence of ultraviolet rays and oxygen, PVC is prone to dehydrochlorination reactions, generating conjugated double bonds, which disrupts the regularity of molecular chains and crystallinity, leading to a decline in mechanical properties. Therefore, unmodified PVC itself does not have the ability to resist ultraviolet rays.
Additive modification: To enhance the UV resistance, additives such as heat stabilizers and anti-aging agents need to be added to the PVC material. These additives can inhibit the photolysis reaction caused by ultraviolet rays, delay oxidation and aging, and thereby maintain the mechanical properties and appearance stability of the material.
2. Weather resistance
Environmental adaptability: UV-resistant PVC baseball needs to maintain stable performance under long-term exposure to light, high temperature, high humidity and other environments. By adding additives, the material’s tolerance to damp and hot environments can be enhanced, reducing quality changes, hardness increases and flexibility losses caused by environmental factors.
Aging inhibition: The addition of additives can effectively inhibit the generation of free radicals, delay material aging, and ensure that the baseball can maintain good physical properties and appearance even after long-term outdoor use.
3. Mechanical properties
Basic properties: PVC material features high strength, high rigidity and high hardness, with a tensile strength of approximately 60MPa and an impact strength of 5-10kJ/m². These characteristics make it suitable for manufacturing baseballs that need to withstand frequent impacts.
Performance maintenance: The PVC material modified for UV resistance can maintain the stability of its mechanical properties under the influence of light and oxidation, avoiding performance degradation caused by material aging and thus extending the service life of the baseball.
4. Chemical stability
Corrosion resistance: PVC material has extremely strong resistance to acids, alkalis and other chemical substances, and can maintain chemical stability in various harsh environments. This feature makes it suitable for outdoor sports scenarios and reduces material damage caused by environmental factors.
Flame retardancy: PVC material is self-extinguishing. When burning in a flame, it releases HCl and extinguishes itself. This characteristic enhances the safety of the material, making it particularly suitable for public sports equipment.
5. Processing performance
Molding characteristics: PVC is an amorphous material with low moisture absorption but poor fluidity. By adjusting the processing technology parameters (such as temperature, pressure, etc.), precise forming of the material can be achieved, ensuring the dimensional accuracy and surface quality of the baseball.
The synergistic effect of additives: The addition of additives such as heat stabilizers and lubricants not only enhances the material’s UV resistance but also improves its processing fluidity, reducing the risk of defects such as bubbles and dead corners.