Product
The appearance of PVC co-extruded board is relatively easy to identify. It has the same smooth surface as PVC celuka board, even a glossy surface. Therefore, sometimes we may not be able to tell whether it is PVC celuka board or PVC co-extruded board just from the surface. But looking at the side of the PVC co-extruded board, we can find that its two surface layers and the middle core have obvious delamination. The two surface layers are not foamed and therefore solid. And the cell pores in the middle core are all of the same size and uniformity. The co-extrusion process also belongs to controlled foaming process. The production equipment of PVC co-extruded board is different from that of PVC free foam board and PVC celuka board. The production equipment of PVC co-extruded board has more than one raw material barrel, but two. One of the barrels provides the raw material for the inner core and the other provides the raw material for the two surfaces. The PVC raw material melt enters the mold from two raw material barrels at the same time and extrudes to form the surface layer, inner core and bottom layer of the board respectively. The PVC foam board produced by the co-extrusion process has a relatively obvious three-layer structure. The top and bottom layers are not foamed, so the PVC co-extruded board has a harder outer layer.
