Compaction behavior and permeability property tests of preforms in vacuum-assisted resin transfer molding using a combined device

A device was designed to study compaction behavior and permeability of preforms in vacuum-assisted resin transfer molding, consisting of a pressure control module, a pressure test module, a thickness test module, and an experimental plate. It can also be used to test the effects of resin flow and the post-filling process on the thickness variation of preforms. Four tests were conducted with the device: (1) compaction tests on preforms of 1, 15, 20, and 25 layers in dry and wet states; (2) in-plane permeability tests on preforms of 1, 5, 10, and 20 layers; (3) transverse permeability tests for 20 layers preforms; (4) determination of the effects of resin flow and post-filling time on preform thickness variation with two liquids. The results show the in-plane permeability decreases as the number of layers increases, and the value for 20 layers is about 62% of one layer. Preform thickness is affected by the liquid viscosity and post-filling time, and the averaged thicknesses of edible oil and Cycom890 resin were 2.12 and 2.03 mm, respectively, at post-filling times of 30 and 40 min, which represent a decrease by 1.9% and 2.9%, respectively, compared with the cases in which there was no post-filling process.