The production process of HDPE pipe (high-density polyethylene pipe) mainly includes the following steps:
Selection and treatment of raw materials: high-quality high-density polyethylene resin is selected as raw materials, and corresponding processing is carried out according to production requirements.
Extrusion: The processed resin is placed in the hopper of the extruder, and the raw material is heated and melted by the rotation of the screw. Subsequently, the molten raw material is extruded through the die of the extruder to form a tube. The material temperature and extrusion speed of the extruder should be adjusted and controlled according to the characteristics of the raw material and the size of the tube.
Tube cooling: Extruded tubing needs to be quickly cooled through a cooling system to solidify and stabilize the shape. Generally, the spray cooling method is used, and the cooling water is sprayed on the surface of the pipe to cool it down quickly.
Bending and cutting: After cooling, the pipe can be produced by a bending machine, or it can be lengthened or beveled by a cutting machine.
Inspection and quality control: Perform visual inspection on the finished pipe, such as the flatness, surface smoothness, color consistency of the pipe, etc., and also need to conduct pressure testing to verify its pressure-bearing capacity. At the same time, quality control is also carried out on raw materials and semi-finished products to ensure product quality.
In addition, there are two main ways to produce HDPE pipes:
Using a twin-screw extruder, the inner and outer walls of the pipe are extruded simultaneously through a double-layer flow channel in the machine head.
Two extruders are used to extrude the inner and outer layers respectively, and then a composite head is used together to extrude the HDPE pipe. Since the latter uses two extruders, the inner and outer layers can be two materials with different formulations.
In addition, there is a production process of HDPE winding reinforced pipe, which mainly uses HDPE resin as raw material and polypropylene (PP) corrugated pipe as the skeleton pipe, which is made by winding molding process. This kind of pipe is characterized by smooth inner surface and special-shaped reinforced structure externally, with excellent strength and rigidity, and environmental protection, safety and convenient construction.
In a word, the production process of HDPE pipes involves multiple steps and links, and the process parameters and quality requirements of each link need to be strictly controlled to ensure the quality and performance of the final product.