PVC fiber reinforced hose is produced by CO extrusion of two extruders.
First, the inner tube is extruded, then the reinforcing fiber is knitted by the braiding machine, and then extruded through the second extruder dies. It is not difficult to understand the close combination of the two layers.
The processing technology of the extruder: the depth of his screw rib is graded, divided into the feeding section (the front, the depth, the space), the compression section (the depth of the shallow), the melting section (more shallow), the homogenization section (sometimes with the melting section); the raw material enters the feeding section, the heat becomes soft, and the screw is pushed forward to the compression section. The section temperature setting is higher than that of the feeding section. It begins to melt and reaches its two stage. It is plasticized. After extrusion, the temperature is still very high and the surface is very sticky. When the inner tube passes through the outer tube mold (its temperature soft product is above 120 degrees), the outer surface melts, and the materials of the second extruders are naturally combined.
In fact, the PPR tube that later appeared, it quickly replaced the aluminum plastic pipe, the reason is that the joint is molten welding, never leakage.