Composite material molds typically have a multi-layered structure, mainly consisting of a mold gel coat layer, reinforcing material layups, and an external support structure. The mold gel coat layer is the working surface of the mold, requiring excellent heat resistance, wear resistance, and gloss. Its thickness is usually controlled at around 1 mm, and it is applied in two layers. The layups are the main structure of the mold, composed of a resin matrix and reinforcing materials. Commonly used resin matrices include isophthalic resin, vinyl ester resin, and epoxy resin. Reinforcing materials often use chopped strand mat, surface mat, or carbon fiber to increase the mold's strength, stiffness, and thermal stability.
In the layup process, the first layup is crucial. Depending on the complexity of the mold shape, 30 g/m² surface mat, 300 g/m², or 450 g/m² chopped strand mat can be selected, using an M450×4~5+RX×N lamination process to ensure the mold reaches the required thickness. The primary function of the external structure of the mold is to evenly distribute external forces to the mold surface, preventing deformation. Its design must adhere to specific principles; for example, the structure should be suspended approximately 1/4 foot above the mold's surface. After demolding, the mold surface requires fine grinding and polishing, starting with 800-grit wet sandpaper and gradually increasing to 2000-grit to achieve Grade A surface quality.
Composite material molds typically possess characteristics such as accurate and stable dimensions, good surface quality, sufficient strength and toughness, good rigidity, ease of operation, and safety and reliability.