There are several process points that need to be paid attention to during the manufacturing process of HDPE pipes to ensure product quality and performance. Here are the main process points:
Raw material selection and pretreatment: First of all, high-quality high-density polyethylene particles should be selected as raw materials to ensure that the raw materials are free of impurities and meet relevant standards. The raw materials need to be pre-treated, including drying and melting, to remove moisture and impurities and prepare them for the subsequent extrusion process.
Extrusion process: Extrusion is the core link of HDPE pipe manufacturing. In this process, parameters such as temperature, pressure and speed of the extruder should be strictly controlled. Temperature is a key factor affecting plasticizing and product quality, which needs to be set according to the raw material formula and extruder head structure. Cooling of the screw is also necessary to prevent the decomposition of the screw stickiness or rough inner wall of the pipe due to excessive frictional heat.
Cooling & Setting: Extruded tubing needs to be quickly cooled through a cooling system to cure and stabilize the shape. Cooling can be spray cooling or sink cooling to ensure uniform cooling of the tube to avoid deformation or cracking.
Traction speed and length control: Traction speed directly affects the wall thickness and inner and outer diameter dimensions of the pipe. The traction speed should be closely matched with the extrusion speed to ensure the uniformity and consistency of the pipe. At the same time, the cut-to-length is carried out according to the needs to ensure that the length of the pipe is accurate.
Quality inspection and control: Strict quality inspection and control are required in all aspects of the manufacturing process. This includes quality inspection of raw materials, parameter monitoring during extrusion, dimensional inspection after cooling and shaping, and final inspection of the finished product. Ensure that each section of pipe meets the relevant standards and requirements.
Cleaning & Packaging: HDPE pipes that have passed the quality inspection need to be cleaned to remove dirt and impurities from the surface. Then, pack it in accordance with the prescribed packaging to ensure that it is not damaged during transportation and storage.