Significance of PMI Foam in Lightweighting
It is commonly believed that PMI foam is about 10-15% heavier than honeycomb cores when both materials offer the same mechanical properties. Therefore, honeycomb is often considered the lighter option. However, comparing only the weight of the core material is not meaningful. A more comprehensive evaluation is needed, considering the entire cured component, including the adhesive films, infusion resins, and surface fibers.
Since honeycomb cores require essential processes such as splicing and filling, large amounts of high-density bonding adhesives are introduced. These adhesives offset the lower density of the honeycomb core, ultimately resulting in a finished product that weighs about 10% more than one made with foam core material.
On the other hand, PMI foam is perfectly suited for various liquid molding processes, including RTM (Resin Transfer Molding) and VARI (Vacuum Assisted Resin Infusion). These processes increase the proportion of carbon fiber or glass fiber in the final product, while reducing the amount of resin. As a result, under the same performance conditions, the final product will be significantly lighter.
