Cable extrusion is an industrial process used to coat metal wire with a plastic insulating layer. It involves several stages to ensure the production of a high-quality, defect-free product. Here is a breakdown of the components and stages involved in cable extrusion:

Feeding: The process starts with loading bare copper wire, aluminum wire, or multiple insulated wires into the payoff.

Tensioning: Proper tensioning is crucial to prevent stretching or breaking of the wire. Tension brakes or dancer accumulators can be used to maintain optimal tension during the extrusion process.

Extrusion: Thermoplastic resin pellets are loaded into a gravity-fed hopper, which supplies the feed area of the extruder. The extruder screw melts and mixes the pellets into a homogeneous liquid, which is then forced to envelop the wire as it passes through a small hole or die. This results in a thin, even layer of insulating material around the wire.

Cooling: After passing through the crosshead, the molten plastic coating needs to be cooled quickly to form a smooth, defect-free surface. Cooling also causes the material to contract snugly around the wire at a consistent diameter and wall thickness. The coated wire is drawn through a chilled water trough and may require multiple cooling stages to solidify.

Pulling: The coated wire is pulled through the extrusion line using a belt wrap, caterpillar, or dual-wheel capstan. The speed of the puller follows the extruder speed to control the diameter of the product. A laser diameter control system can be added to trim the capstan speed for accurate diameter control.

Wire Marking & Inspection: At this stage, the wire is coated with a solid thermoplastic coating, and printing or marking can be applied. Inspection protocols may include laser diameter inspection and checking the integrity of the coating. The inspection system can adjust the capstan speed to ensure consistent diameter.

Coiling: In the final production stage, the coated wire is wound onto a reel. The size and speed of the reel determine the appropriate coiling machine setup. Different types of coiling machines are available, depending on the application requirements.