Composite materials. One of the most common materials for the back plate of the door head is a floor. Aluminum-plastic plate is a composite material made of coated aluminum after chemical treatment and processed on special aluminum-plastic plate production equipment. Door head bottom plate can be divided into color steel gusset plate, three-dimensional gusset plate, painted glass, aluminum-plastic plate, ecological wood, anticorrosive wood, PVC sculpture, iron sculpture, etc.