7.10 Liquid Molding

Liquid molding is a composite fabrication process that is capable of fabricating extremely complex and accurate dimensionally parts. One of the main advantages of liquid molding is part count reductions, in which a number of parts that would normally be made individually, and either fastened or bonded together, are integrated into a single molded part. Another advantage is the ability to incorporate molded-in features, such as a sandwich core section in the interior of a liquid molded part.

Resin transfer molding (RTM), the most widely used of the liquid molding processes, is a matched mold process that is well suited to fabricating three-dimensional structures requiring tight dimensional tolerances on several surfaces. Excellent surface finishes are possible, mirroring the surface finish of the tool. The major limitation of the RTM process is the relatively high initial investment in the matched-die tooling. Sufficient part quantities, usually in the 100 5000 range, are necessary to justify the high non-recurring cost of the tooling. A summary of the advantages and disadvantages of the RTM process are given in Table 7.5.