Production process of PE pipe extrusion line

In the PE pipe extrusion molding system, the mold is the key to the product quality and production efficiency. This paper mainly analyzes the influencing factors of high-speed extrusion production of PE pipes from the mold aspect .

Influence of extrusion die. In the extrusion production of pipes, the quality of the extrusion die plays a very important role in the quality of the product. For processing PE materials, high-speed production extrusion dies should have the following requirements:

(1) The material can be further fully mixed in the die and then extruded from the die with a uniform melt;

(2) Ensure that the tube blank does not have a flow orientation effect in the extrusion die, ensure that the material maintains a low melt pressure and a stable extrusion balance in the extrusion die, and minimize the compression ratio;

(3) It can provide the most appropriate time for the material to stay in the extrusion die;

(4) It can ensure that the material maintains a low material temperature in the die to prevent the material from lateral flow and premature oxidation when it is extruded in the extrusion die.

Extrusion produced grades typically have melt indices less than 1 and medium to broad MWD . During processing, low MI can achieve suitable melt strength. Wider MWD grades are more suitable for extrusion because they have higher production speeds, lower die pressures and a reduced tendency to melt fracture.

PE has many extrusion applications such as wire, cable, hose, pipe and profile. Tubing applications range from small section yellow pipe for natural gas to 48in diameter thick wall black pipe for industrial and urban piping. Large diameter hollow wall pipes are growing rapidly as a replacement for rainwater drains and other sewer lines made of concrete.

Sheets and Thermoforming: Thermoformed liners for many large picnic coolers are made of PE for toughness, light weight and durability. Other sheet and thermoformed products include fenders, tank liners, pan guards, shipping boxes and tanks. A large and rapidly growing sheet application is mulch or pool bottoms, which are based on MDPE 's toughness, chemical resistance and impermeability.

When the pipe is extruded through the extrusion die, it must pass through the high-pressure water cooling sizing system. The influence of the cooling sizing device, the cooling and sizing system in the pipe production line is also an important part in the pipe extrusion production line, and its performance directly affects the entire line. The performance of the production line affects the efficiency of production and the quality of the inner and outer surfaces of the pipe. The molten material is cooled down on the inner surface of the sizing sleeve, and forms a layer of agglomerate surface layer, which ensures the accurate outer diameter of the pipe, and ensures the stability and normal traction and extrusion of the pipe. Therefore, the structure, machining accuracy and cooling method of the sizing sleeve are very important to the quality of the processed PE pipe.