Preparation And Properties Of Water-Soluble Core-Materials Applied For RTM

Composite components with complicated internal structures were difficult to be manufactured integrally by traditional RTM process because it is hard to remove the core mould for the process. Water-soluble core-mould materials could be used to solve the problem due to their mechanical properties and water solubility. In this paper, manufacturing process and properties of water-soluble core-materials made of quartz sand and adhesive were studied(1) Basic properties, such as viscosity and gel-forming time of Poly vinyl pyrrolidon(ePVP) solution and MERKA2405 were studied. FT-IR was used to analyze main groups of the two adhesive. The two adhesives were stable at room temperature but theviscosity increased with time due to the volatilization of solvent in the adhesives.(2) Manufacturing process of the water-soluble core-mould materials was developed. Effects of temperature, ratio of adhesives and quartz sand, diameters of the quartz sand and surface treatment of the quartz sand on the process were investigated. Results show that the curing temperature of 130℃and 140℃for PVP and MERKA2405 adhesives may obtain core mould samples with better mechanical properties. Higher flexure and compressive strength will benefit from ratio of adhesives and quartz sand of 1.6:10 and surface treatment.(3) Dissolving mechanism and measuring method of the water-soluble core-mould materials was developed. Effects of ratio of adhesives and quartz sand, diameters of the sand, temperature and pH values of water on dissolving rates were investigated. The results show higher dissolving rates will benefit from smaller ratio of adhesives and quartz sand, bigger diameters of the sand, higher temperature of water.(4) Finally, a small water-soluble core-mould structure with typical features was fabricated by the method developed in this paper and was used to manufacturing a composite product by RTM process. The properties of the composite product show that the manufacturing method of the water-soluble developed in this paper is suitable for RTM process.