Discontinuous fiber composites (DFC) are a type of composite material that are made by compressing pre-impregnated fiber chips, or prepreg chips, which consist of unidirectional fibers and a matrix material. These chips are typically arranged in a specific orientation and then compressed under high pressure and temperature to form the final composite part.
One potential issue with the manufacturing process for DFCs is the occurrence of cracks between the chips. This can happen when the curing cycle is not well monitored, as thermal stresses can build up between adjacent chips when they are heated to the curing temperature. These thermal stresses can cause the matrix material to crack or fracture, resulting in gaps or voids between the chips in the final composite part.
To prevent this issue, it is important to carefully monitor and control the curing cycle, including the temperature and pressure applied during the compression molding process. Additionally, the use of thermoplastic matrices instead of thermoset matrices may also help to reduce the occurrence of cracks, as thermoplastics typically have better toughness and can better handle the thermal stresses generated during the curing process.
