What is the Core structure and working principle of extruder ?

Core structure
Hopper: The entrance of raw materials (such as plastic particles) to ensure continuous feeding.
Barrel: It is equipped with a rotating screw inside, and a heating ring and cooling device are installed outside to control the melting temperature of the material.
Screw: The core component is divided into three sections according to its function:
Feeding section: Convey solid particles and preheat.
Compression section: Generate pressure by decreasing thread depth to melt the material.
Metering section: Homogenize the melt and stabilize the output pressure.
Die: Determines the cross-sectional shape of the product (such as tubular or sheet-shaped), and must be resistant to high temperature and high pressure.
Cooling system: Water cooling or air cooling device, quickly solidify the molded product.
Drive motor and reducer: Provide screw rotation power, adjust the speed to control production capacity.

Working principle
Plasticization process: The raw material enters the barrel from the hopper, the screw rotates to push the material forward, and the barrel is heated (or friction heat is generated) to melt the solid particles into a uniform viscous fluid.

Mixing and pressurization: The compression section of the screw compacts the melt and removes bubbles, while the shearing action enhances the homogeneity of the material.

Molding and cooling: The molten material is extruded through the die, shaped by the cooling system (such as water cooling in water pipes and air cooling in thin films), and finally cut or coiled into finished products.