FEP Extruder

FEP is a type of fluoroplastic characterized by a high melting point and high melt viscosity. During the melting process, fluoropolymer materials undergo melting, plasticization, and degassing pelletization. The fluorine ions released from the material exhibit strong corrosiveness, making the extrusion process for FEP particularly challenging.

Chuangbo recommends the TSH series twin-screw extruder for FEP extrusion, featuring barrels and screws made from Hastelloy C-276.

Chuangbo FEP pelletizing production line consists of a feeding system, a twin-screw extruder, a pelletizing system, and a control system.

As a high-performance fluoroplastic, FEP (Fluorinated Ethylene Propylene Copolymer) presents manufacturing challenges due to its high melting point, high melt viscosity, and the tendency for melt fracture and surface defects during processing. FEP melt behaves as a viscoelastic material, with lower critical shear rates and higher melt viscosity compared to polyethylene with the same melt index. This results in low extrusion efficiency and reduced surface smoothness during high-speed extrusion. Additionally, FEP’s narrow molecular weight distribution and short elastic relaxation time mean that significant elastic energy is stored in the extruder die. When released during extrusion, this elastic energy can cause surface defects like “sharkskin” or “ribbing” patterns.

FEP Extruder

Chuangbo’s FEP twin-screw extruder offers better shearing and plasticizing performance, improving FEP processing efficiency.

The FEP extruder provides precise temperature control to maintain stable melting without compromising the polymer quality. FEP processing temperatures typically range between 280°C and 380°C, with barrel temperatures controlled from 280°C to 380°C, and die head temperatures not exceeding 380°C. This helps reduce melt viscosity and prevents resin decomposition.

The FEP extruder enables better control over pressure and speed. Strictly regulating these parameters ensures smooth extrusion of FEP pellets, avoiding surface defects or excessive internal stress.

FEP extruders are made of corrosion-resistant materials. The barrel and screw of our extruders are crafted from Hastelloy C-276, which can withstand the chemical aggressiveness of molten FEP.

Chuangbo recommends high-torque twin-screw extruders for FEP. Due to FEP’s high melt viscosity, the extruder must generate sufficient torque and pressure for smooth extrusion without causing melt fracture.

A water-ring pelletizing machine is used in tandem with the extruder. This allows FEP pellets to solidify through a rapid cooling system and then be cut into granules by a cutting machine. The efficient cooling system ensures the extruded product is quickly solidified while maintaining dimensional accuracy.