Aluminum composite panels (ACM) are a type of composite material made from two thin sheets of aluminum bonded to a polyethylene core. They are lightweight, durable, and easy to maintain. ACM panels are often used in exterior applications, such as cladding, roofing, and signage. Here are some of the benefits of using ACM panels: Lightweight. ACM panels are lightweight, which makes them easy to install and maintain. Durable. ACM panels are durable and can withstand the elements.