Silicone Wire Insulation/Sheath Extrusion Line 80m/min

Thermoplastic Wire Extruders: Vertical Versus Horizontal
A horizontal extruder is typically the primary application method. However, a vertical extruder may be incorporated for coextrusion capabilities. Vertical extruders are often used to supply a secondary coating into the crosshead, for example applying a color coating, stripe, or alternative exterior coating material (usually for improved heat or moisture resistance.)

One major benefit of vertical co-extrusion is that color changes are easier to facilitate. For OEMs producing a range of color-coded materials, co-extruding a white PVC coating and a cosmetic layer via a vertical extruder expedites change from one color to another.

Thermoplastic resin pellets are loaded into a gravity-fed hopper supplying the feed area of the extruder. The feed throat area is cooled to prevent bridging, which occurs when material melts in the opening and clogs the extruder barrel.

The extruder applies the coating to the wire by forcing the melted polymer to envelop the wire as it passes through a small hole or die. The extruder screw augers the pellets into the barrel where they are melted and mixed into a homogeneous liquid. As the screw revolves inside the extruder barrel, it pushes out a constant stream of liquified thermoplastic resin matched to the speed of the wire as it moves through the crosshead. The result: a thin, even layer of insulating material around the wire. The die size, extruder speed, and temperature of the material all affect the resulting wall thickness.

Applications:

The production line is suitable for extrusion of silicone wires and cables.

Main process parameters:

Applicable conductor: 10mm²-120m²;

Finished outer diameter: φ6mm-φ24mm;

Design speed: 80m/min.