Extrusion Grade FEP Pellet
Brief Specification of Extrusion Grade FEP Pellet DS618
1: Appearance: Translucent particle
2: Melting Index :12-28 g/min
3:Melting Point :265 around
4:Volatile: 0.1% Max
Technical Specification of Extrusion Grade FEP Pellet DS618
Translucent particles,without impurities such as metal debris and sand,containing visible black particles percentage point less than 2%
Elongation at break ≥
Heat stress Cracking Resistance
Extrusion Grade FEP Pellet is a crystalline polymer with lower crystallinity than polytetrafluoroethylene. When Extrusion Grade FEP Pellet melt slowly cools to below the melting point of crystal, macromolecules recrystallize and crystallinity is 50%-60. Between %; when the melt is rapidly cooled by quenching, the degree of crystallinity is small, between 40% and 50%. The crystal structure of Extrusion Grade FEP Pellet is spherulitic structure, and it has certain differences depending on the resin and processing temperature and heat treatment method.
Extrusion Grade FEP Pellet has better processing performance. The insulating layer of the wire and cable can be covered by a usual extrusion method. In order to properly design the extruder and mold, control and master the processing conditions ofExtrusion Grade FEP Pellet, we should first understand the rheological properties of Extrusion Grade FEP Pellet. The relationship between shear stress and shear rate of Extrusion Grade FEP Pellet at 390 °C. Its viscosity μA decreases as the shear rate increases. The critical shear rate of Extrusion Grade FEP Pellet, if the shear rate exceeds this value, causes a uniform flow of the plastic, resulting in a rough, matte and delaminated surface. The critical shear rate of Extrusion Grade FEP Pellet is quite different from that of polyethylene and nylon, so the problem of melt fracture is particularly serious.
Extrusion Grade FEP Pellet has two characteristics in processing, namely, a tendency to melt fracture and a particularly high stretchability in a molten state. In order to eliminate or improve melt fracture and improve productivity in wire and cable production, the following measures are usually taken: First, the extruded mold is used to expand the opening of the mold to slow down the flow rate of the polymer at the die, making it low. Extruding the resin at a moderate extrusion speed at a critical shear rate and increasing productivity; second, increasing the temperature of the molten resin as much as possible without decomposing the resin to lower the viscosity of the resin, thereby increasing its critical shear rate.
Main Application of Extrusion Grade FEP Pellet DS618