Detailed Production Process Analysis
1.Preparation: First, the PE-RT raw material is sucked into the dryer through a vacuum feeder to ensure the dryness of the raw material. This is the first step to avoid air bubbles in the raw material pipes and to ensure quality.
2.Screw-based plasticizing: After drying, the raw materials enter the heart of the production line-the single-screw compressor. The screw, through rotation, shearing, and heating, gradually restores the raw materials to a homogeneous melt. To accommodate high-speed production, the screw typically employs a barrier or high-efficiency BM-type design with a length-to-diameter ratio of approximately 33:1. The barrel heating temperature is precisely controlled between 180-225℃ depending on the raw material to ensure optimal plasticizing effect and output.
3.Mold forming: The adapter's plastic is pushed into a spiral mold. This specialized mold ensures uniform melt distribution, stable pressure, and eliminates weld lines, thus preventing the production of smooth, flawless tube blanks.
4.Sizing and Cooling: These are crucial steps determining the dimensional accuracy and performance of the pipe.
Vacuum Sizing: The soft pipe blank enters a vacuum sizing chamber and, under a negative pressure of -0.02 to -0.06 MPa, is tightly fitted onto the sizing sleeve, precisely shaping the outer diameter and roundness of the pipe. Advanced equipment uses disc-type sizing sleeves with lower hardness to avoid scratching the pipe surface.
Stage Cooling: The pipe then passes through several cooling tanks, typically employing a critical cooling method of warm water pre-cooling and cold water shaping to eliminate internal stress and ensure the long service life of the pipe. The total cooling length of the entire production line can reach 17-23 meters or even longer.
5.Traction, coding, and cutting: The cooled and shaped pipes are pulled out at a constant speed using a tracked traction machine. The traction speed and error speed are precisely synchronized to ensure uniform wall thickness. During the traction process, an inkjet printer prints product specifications, brand, production date, and other information online. Finally, according to production needs (straight pipes or coils), a cutting machine or winding machine cuts the pipes to the required length or coil length.
6.Winding and Packaging: For small-diameter pipes such as underfloor heating pipes, a dual-station automatic winding machine sequentially winds continuous pipes into bundles and automatically switches stations to achieve intermittent production. Constant winding tension ensures a tight and aesthetically pleasing coil appearance. After passing inspection, the coils are packaged and stored.