Anti-Aging Methods for Plastic Molds of Photovoltaic Modules

The hardness and toughness of the mold shall be reasonably matched. While resisting the wear and aging caused by continuous scouring of glass fiber, it can slow down the material degradation under repeated high temperature, and prevent surface peeling, oxidation and blackening of the cavity surface. Reasonable material selection and heat treatment can effectively improve the overall structural stability of the mold, reduce the sensitivity to harsh molding environments, and lay a solid foundation for long-term anti-aging operation of the mold.

2. Cavity Surface Strengthening and Protective Coating Treatment
Most mold aging starts from surface damage. Acidic precipitates produced by high-temperature decomposition of photovoltaic modified materials will continuously erode key areas such as cavities, runners and gates, resulting in pitting corrosion and oxide layers. Targeted surface strengthening shall be carried out for high-load molding positions, including nitriding treatment, PVD hard coating, nano-ceramic coating and hard chrome electroplating, to form a dense isolation protective film on the metal surface.
Nitriding treatment can significantly improve the high temperature oxidation resistance and fatigue resistance of the mold, and strengthen the surface hardness; various hard coatings can isolate corrosive gas and moisture from contacting the metal substrate, reduce the surface friction coefficient, and relieve mold sticking, carbon deposition and chemical aging caused by plastic residue adhesion. The use of release agents and oily auxiliaries shall be strictly controlled to prevent chemical agents from penetrating into mold gaps for long-term erosion, so as to further delay the process of surface corrosion and aging.
3. Molding Process Optimization to Reduce Working Condition Damage
Unreasonable injection molding parameters will accelerate the thermal aging and mechanical aging of molds. In daily production, the barrel temperature and mold temperature shall be strictly controlled to prevent excessive temperature melting and long-term material retention, and reduce the accumulation of corrosive flue gas and carbon deposition caused by excessive decomposition of plastics. The injection speed, holding pressure and cooling time shall be adjusted scientifically to weaken the high-speed scouring wear of glass fiber melt on the cavity wall and reduce the cumulative micro damage on the surface.
The opening and closing rhythm of the injection molding machine shall be standardized to slow down the mold clamping impact and friction loss, protect guide pins, guide sleeves, positioning locks and parting surfaces, and reduce mechanical fatigue aging caused by frequent movement and friction. Avoid long-time high-temperature standby of the mold, and cool down slowly after shutdown to prevent structural stress cracking caused by rapid cooling and heating, so as to improve the overall thermal cycle resistance of the mold.

4. Standard Daily Maintenance and Anti-Corrosion Management
Moisture, workshop dust and shutdown rusting are important inducing factors for natural aging of molds. During continuous production, the cooling water circuit shall be kept unobstructed, scale and impurities in the water circuit shall be cleaned regularly to ensure uniform and stable mold temperature, and prevent cavity rust caused by condensed water formed by local temperature difference. After daily production, the glue stains, carbon deposits and acidic residues in cavities, runners and exhaust grooves shall be thoroughly cleaned with neutral special cleaning agents, and strong acid and alkali solvents are prohibited from wiping the mold surface.
After cleaning, dry rust inhibitors or anti-rust oil shall be evenly coated in cavity gaps, thimble holes and parting surfaces for sealing protection. For long-term shutdown and stored molds, overall moisture-proof packaging shall be adopted and placed in a dry and constant temperature environment, with regular re-inspection of anti-rust status to comprehensively block oxidation and rust aging.
5. Mold Structure and Exhaust System Optimization
Flame-retardant photovoltaic materials are easy to produce a large amount of cracked gas during molding, and gas retention will cause local corrosion, yellowing and pitting aging. The exhaust structure of parting surfaces, inserts and product ends shall be optimized, the depth and layout density of exhaust grooves shall be reasonably increased, and harmful waste gas shall be discharged in a timely manner to reduce the adhesion and retention of corrosive gas inside the cavity. The layout of runners and gates shall be adjusted to reduce dead angles of melt retention, lower the generation of plastic carbon deposition, and avoid long-term adhesion of stubborn carbon deposits to corrode the mold surface.
Worn and corroded local parts adopt modular insert design, which can be replaced and maintained independently after aging without overall mold renovation. This mode not only reduces the loss cost, but also maintains the long-term molding accuracy and surface state of the mold.
Conclusion
The aging of plastic molds for photovoltaic modules is the comprehensive result of chemical corrosion, high temperature oxidation, alternating cold and heat, mechanical wear and other multiple factors. A single protection method cannot achieve long-term anti-aging effects. Only by constructing a complete protection system covering material selection and heat treatment in the early stage, surface strengthening and protection in the middle stage, reasonable control of production processes, daily cleaning and anti-corrosion maintenance, and mold structure optimization, can it adapt to the special molding working conditions of photovoltaic modified plastics.
Scientific and standardized anti-aging schemes can effectively solve common aging problems such as mold rust, wear, cracking and carbon deposition corrosion, stabilize the appearance and dimensional accuracy of photovoltaic plastic parts, extend mold service life, reduce maintenance and replacement frequency, and provide reliable guarantee for large-scale and low-cost sustainable production of photovoltaic accessories.