What are the quality control points of HDPE Pipe Making Machine?

1. Raw material control
Purity and quality: Strictly screen the HDPE resin raw materials to ensure their purity. Impurities will reduce the physical properties of the pipe, such as strength and corrosion resistance. Check the qualifications of the raw material supplier and product quality certification to ensure that the raw materials meet the requirements for producing high-quality pipes.
Test the basic performance indicators of the resin, including melt flow rate (MFR) and density. MFR determines the processing performance of the resin, and the appropriate MFR range can ensure the smoothness and uniformity of the pipe extrusion process. Density affects the strength and hardness of the pipe and must meet the design specifications of the pipe.
Drying treatment: HDPE resin may absorb moisture during storage and transportation. Moisture will form bubbles during the pipe extrusion process, affecting the quality of the pipe. Therefore, before putting it into production, the raw materials must be dried to control the moisture content at an extremely low level, generally required to be less than 0.05%.
2. Extrusion process control
Temperature control: The temperature of the barrel and mold is a key factor. The barrel temperature should be precisely adjusted according to the characteristics of HDPE and the extrusion speed of the pipe. Usually, the barrel temperature is between 160 - 200 ° C, and the temperature in different areas can have an appropriate gradient change to ensure that the resin is fully melted and uniformly plasticized. The mold temperature also needs to be set reasonably. Too high or too low will affect the surface quality and dimensional accuracy of the pipe.
Screw speed and traction speed: The screw speed determines the material conveying speed and extrusion volume. According to the diameter and wall thickness requirements of the pipe, combined with the characteristics of the resin, the screw speed should be reasonably adjusted. At the same time, the traction speed must match the screw speed to ensure uniform wall thickness of the pipe. If the traction speed is too fast, the pipe will become thinner; conversely, the pipe will become thicker.
3. Tube molding quality control
Dimensional accuracy: Real-time monitoring of the outer diameter and wall thickness of the pipe. Use high-precision measuring equipment such as laser diameter gauges and ultrasonic wall thickness gauges to ensure that the pipe size meets the standard requirements. The outer diameter deviation should generally be controlled within ±1%, and the wall thickness deviation should be controlled within ±10%.
Surface quality: The surface of the pipe should be smooth and flawless. Check whether there are bubbles, cracks, corrugations and other defects on the surface of the pipe. These defects may be caused by raw material problems, inappropriate extrusion temperature, rough mold surface or uneven cooling. A comprehensive inspection of the production process is required to detect and solve problems in a timely manner.
Performance testing: Physical performance tests are performed on the pipe, including tensile strength, ring stiffness, environmental stress cracking resistance, etc. These performance indicators are directly related to the reliability and durability of the pipe in practical applications. Sampling tests are carried out in accordance with relevant standards to ensure that each batch of pipes can meet the requirements of use.
If you want to know more about the quality control points of HDPE Pipe Making Machine, please contact East Point Machinery, our technical team will tailor the most suitable product solution for you.