Fabrication of Mechanically Robust Water-Soluble Core Molds and Experimental Validation to Manufacture a Composite Part

In this work, a core mold which combines excellent high-temperature compressive properties and rapid water solubility was successfully fabricated by using polyvinyl alcohol (PVA) as the adhesive and quartz sands as reinforcing particles. The influence of the molecular weight and alcoholysis degree of PVA, the concentration of PVA and the size of the quartz sands on the compressive performance and water penetration rate of core molds was studied in detail. The results revealed that core molds which were prepared using PVA-4 (i.e., a degree of polymerization of 2400 and an alcoholysis degree of PVA of 88%) and 160–200 mesh quartz sands with a mass ratio of 1.2:10 possessed a 160 °C compressive strength of 7.4 MPa, a 160 °C compressive modulus of 179.3 MPa and 50 °C water penetration rate of 0.94 mm/s. Furthermore, a validation experiment was conducted to verify the efficacy of using the as-prepared core mold to fabricate a hollow composite part, which shows a promising application in industrial sectors.