How to avoid micro cracks inside the epoxy resin board during processing?

1. Choose a crack resistant grade Optimization of glass fiber content: Priority should be given to using epoxy resin boards reinforced with medium alkali glass fibers (such as EC10-13) or hybrid fibers (glass fiber+aramid), which have a 20% -30% higher elongation at break than high alkali fiber boards (ordinary boards have about 1.5% -2%, and crack resistance can reach 2.5% -3%), and better toughness. Toughening modification process: When high crack resistance is required, epoxy resin boards modified with rubber elastomers (such as CTBN) or thermoplastic resins (such as polysulfone) can be selected, and their impact strength can be increased by 40% -60% (ordinary boards have an impact strength of about 25-35 kJ/m ², while modified boards can reach 40-55 kJ/m ²).

2. Eliminate internal stress hazards Time treatment: Before processing the new board, it should be insulated in a 60-80 ℃ oven for 2-4 hours to release any residual internal stress during the production process (which can reduce the initial stress by 30% -50%). Humidity control: The processing environment humidity should be ≤ 60%. Wet boards (with a moisture content greater than 0.3%) should be dried at 80 ℃ for 12 hours to avoid moisture vaporization and microcracks during processing.