Sheath extrusion is an extrusion method in which liquid metal is coated on the core wire material. This method is specially used for cable sheathing, so it is also called cable sheathing extrusion. There are two types of lead sheathed cable extrusion and aluminum sheathed cable extrusion. The process is: inject molten lead or aluminum into a vertical extrusion cylinder, the extrusion rod exerts a slight pressure on the liquid metal in the cylinder, and when the metal solidifies to an appropriate temperature, two strands of metal flow into the cavity at the lower part of the extrusion cylinder. It is wrapped on the core wire material introduced in the horizontal direction, and is extruded from the die hole together with the core wire welding to form a uniform, continuous and complete sheath (see picture). The thickness of the sheath is mainly controlled by adjusting the relative position of the mold and the core wire material. Cable sheath extrusion diagram The original sheath material is lead. Due to its poor strength and high density, it has been replaced by aluminum with low density, corrosion resistance, good plasticity, and sufficient strength.