Pressurized Infusion: A New and Improved Liquid Composite Molding Process

Abstract

Vacuum-assisted resin transfer molding (VARTM) has several inherent shortcomings such as long mold filling times, low fiber volume fraction, and high void content in fabricated laminates. These problems in VARTM mainly arise from the limited compaction of the laminate and low resin pressure. Pressurized infusion (PI) molding introduced in this paper overcomes these disadvantages by (i) applying high compaction pressure on the laminate by an external pressure chamber placed on the mold and (ii) increasing the resin pressure by pressurizing the inlet resin reservoir. The effectiveness of PI molding was verified by fabricating composite laminates at various levels of chamber and inlet pressures and investigating the effect of these parameters on the fill time, fiber volume fraction, and void content. Furthermore, spatial distribution of voids was characterized by employing a unique method, which uses a flatbed scanner to capture the high-resolution planar scan of the fabricated laminates. The results revealed that PI molding reduced fill time by 45%, increased fiber volume fraction by 16%, reduced void content by 98%, improved short beam shear (SBS) strength by 14%, and yielded uniform spatial distribution of voids compared to those obtained by conventional VARTM.

Fiber-Reinforced Polymer Composites: Manufacturing, Properties, and Applications

“…Vacuum force causes the resin to be sucked through the perforated tubes over the fibers to consolidate the laminate structure, as shown in Figure 7. This process leaves no room for excess air in the composite structure, making it popular for manufacturing large objects like boat hulls and wind turbine blades [141,142]. For the improvement in the strength of textile composites, natural fibers are surface treated.…”

Physical and Mechanical Properties of Natural Leaf Fiber-Reinforced Epoxy Polyester Composites

“…The vacuum force causes the resin to be sucked through the perforated tubes over the fibres to consolidate the laminate structure. This process leaves no space for excess air in the composite structure, making it famous for producing large objects like boat hulls and wind turbine blades [ 55 , 56 ]. Compression moulding is a high-volume thermoset moulding process that employs costly but extremely durable metal dies.…”

Carbon nanotubes in carbon/epoxy multiscale textile preform composites: A review

“…Resin is applied on the fiber preforms placed inside a female mold or on a male mold with a subsequent curing process to ensure the desired composite shape. Compression molding, injection molding, pultrusion, resin transfer molding (RTM), [ 119,120 ] vacuum‐assisted resin transfer molding (VaRTM), [ 121‐123 ] and resin film infusion (RFI) [ 124,125 ] processes are most commonly utilized in the composite industry. Figures 13 and 14 show schematically some of the closed molding composite fabrication methods such as vacuum bag molding, [ 126 ] VaRTM, [ 127 ] and RFI molding, [ 128 ] respectively.…”