Cardboard paper generally refers to the upper and lower layers of the carton, if there is a multi-layer carton. Corrugated paper refers to the layer that is pressed into the middle of the carton. The two paper production equipments are the same, but the raw materials and technical requirements are different. For example, there is a layer of noodles on the surface of the cardboard paper to be printed, so the raw materials are different and the requirements are different. The surface, middle and bottom of the corrugated paper are the same raw materials. In fact, this type of cardboard is divided into liner paper, core paper, corrugated paper according to the purpose of the carton.