How to Choose PMI Foam Density for Lightweight UAV Sandwich Structures
Introduction: Five weighted checks and three process variables help select PMI density, controlling final mass, resin uptake, and repeatable UAV sandwich performance. 1. Choosing PMI Foam Density for Stable UAV Sandwich Panel Mass A lightweight UAV sandwich panel is not defined by the mass of its dry core alone. The finished structure contains skins, resin, adhesive, local reinforcements, inserts, paint, and a production history that can add unexpected weight. PMI foam density is therefore a design input rather than a shortcut to a target mass. The relevant question is whether a chosen density supports the required load path and cure cycle while helping the factory produce conforming components within a stable mass range. This distinction matters because a panel that is light in a flat coupon trial can become inconsistent once it includes curvature, cutouts, hard points, and production-scale infusion. A lower-density core may reduce dry mass, yet it can still be the wrong cho...