PVC PVC-U products from raw powders are formed through a process pressure and temperature. Two main processes are used in the production include continuous extrusion products such as pipes and molded to separate products such as fittings.
Modern scientific-industrial process PVC-U requires advanced methods for precise control of process variables. Polymer material used, the powder is free flowing require adding various stabilizers and lubrication. For this reason, the formulation, and then mixing, two factors are vital in the production process.
Polymers and additives are carefully weighed and then mixing unit (mixer) are. High-speed mixers, raw materials are mixed to a dry mixture is homogenous. At this stage, a temperature of about ° C190 caused by friction and shearing mixer. Different stages of mixing, additives and melted PVC cover grains on the surface. After reaching the right temperature, the mixture is automatically transferred to a cooling tank and its temperature quickly decreases to around ° C40.
Heart extruding PVC-U pipe manufacturing process, which has a cylinder can be controlled with heating elements in the spiral / spin elaborate mazes. New extruders are highly sophisticated machines which are carefully designed to push and cut the material in the whole process is controllable.
Product previous step is sent to the cylinder and spiral heat, pressure and cut into a "molten" to reach. While passing through the spiral, PVC particles from a number of districts that have passed thermal density, melt flow is more uniform and degassing. Last increases the pressure inside the mold to melt the pass and based on the size and profile pipes to form. The design template is very important, because a large impact on uniformity properties of the final product.
After the tube was removed from the extruder die, a calibrator to help the flow of air or vacuum reaches the optimal size. Calibrator during about three times the diameter of the pipe. The length for fixed before at the end of the pipe diameter in a water bath temperature-controlled cooling is necessary.