Aluminum Composite Panel

Aluminum composite panel, commonly abbreviated ACM, is a flat panel product made of two thin aluminum sheets bonded to either side of a non-aluminum core, typically a low-density polyethylene plastic, giving a rigid, flat, lightweight sheet far stiffer than a solid aluminum sheet of comparable weight. Developed in the 1960s and widely adopted from the 1980s onward, it became a common exterior cladding and sign material because it can be factory-finished in a broad range of colors and easily fabricated, cut and bent into rainscreen panels for curtain wall and facade systems. Its combustible plastic core became a subject of building-code scrutiny after several high-profile cladding fires, prompting a shift toward fire-retardant or mineral-filled cores in many jurisdictions.