The core of improving the anti-aging PVC baseball material lies in enhancing the material’s weather resistance, mechanical properties and processing stability through chemical modification, blending modification and the addition of additives. The following is an analysis from the aspects of material formula design, modification technology and performance optimization:
First, material formula design
Selection of base resin
When PVC is used as the main material, models with higher molecular weight and better thermal stability should be given priority to reduce the risk of thermal degradation during processing. High polymerization degree PVC can reduce molecular chain breakage and enhance the anti-aging performance of the material.
Plasticizer optimization
Traditional plasticizers are prone to migration, causing materials to become brittle. High-molecular-weight and environmentally friendly plasticizers (such as trimellates) can be used instead, which can not only maintain the flexibility of the material but also reduce volatilization losses. Meanwhile, the amount of plasticizer used needs to be precisely controlled to avoid a decrease in strength due to excessive use.
Anti-aging additive system
Light stabilizer: The addition of hindered amine light stabilizers (HALS) can capture free radicals and inhibit photo-oxidation reactions, thereby extending the outdoor service life of materials.
Heat stabilizer: Calcium-zinc composite stabilizers are used to replace traditional lead salts, reducing heavy metal pollution while enhancing thermal stability.
Antioxidants: The combination of hindered phenolic and phosphite ester antioxidants synergistically inhibits thermal oxidative aging.
Second, the modification technology path
Blending modification
Blending with elastomers: The addition of acrylate elastomers (ACR) or chlorinated polyethylene (CPE) can significantly enhance the impact toughness of the material and simultaneously improve its low-temperature performance.
Blending with inorganic fillers: Adding nano-scale calcium carbonate or talcum powder can not only enhance the rigidity of the material but also improve dimensional stability. However, attention should be paid to the surface treatment of the packing to avoid agglomeration.
Chemical modification
Chlorination modification: By increasing the chlorine content of PVC through chlorination reaction, the heat resistance and flame retardancy of the material can be enhanced, but the degree of chlorination needs to be controlled to avoid increased brittleness.
Grafting modification: Grafting functional monomers (such as acrylate) onto the PVC molecular chain can improve the compatibility and interfacial bonding force of the material.
Cross-linking technology
The use of radiation crosslinking or chemical crosslinking agents (such as peroxides) to form a three-dimensional network structure of PVC molecular chains can significantly enhance the material’s heat resistance, solvent resistance and mechanical properties. However, the crosslinking degree needs to be optimized to avoid embrittlement.
Third, performance optimization direction
Improvement of mechanical properties
The tensile strength and flexural modulus of the material can be enhanced through blending modification or fiber reinforcement (such as glass fiber).
Optimize the processing techniques (such as injection temperature and pressure) to reduce internal defects and enhance the density of the material.
Enhanced weather resistance
Adding ultraviolet absorbers (such as benzotriazole) to the formula in synergy with light stabilizers can effectively shield ultraviolet rays and delay the yellowing and aging of materials.
The weather resistance of the material is verified and the formula is optimized through aging tests simulating outdoor environments (such as accelerated aging with xenon lamps).
Improvement of processing performance
Add internal and external lubricants (such as calcium stearate, polyethylene wax) to reduce melt viscosity and improve fluidity.
The pre-plasticizing technology or twin-screw extruders are adopted to enhance the mixing effect and ensure the uniform dispersion of additives.
Fourth, environmental protection and safety
Replace harmful additives
Avoid using stabilizers containing heavy metals such as lead and cadmium, and instead use environmentally friendly calcium-zinc stabilizers or organotin stabilizers.
Low volatile organic compounds (VOC)
Low-voc plasticizers and additives are selected to reduce the harm of materials to the environment and human health during use.
Recyclable design
By optimizing the formula and processing technology, the materials can be easily recycled and reused after being scrapped, which meets the requirements of sustainable development.