As an indispensable and important part of modern power, communication and automation control systems, the manufacturing process of plastic wires and cables needs to go through a series of precise and complex process steps to ensure the performance and quality of the final product. The following is the basic process of plastic wire and cable manufacturing, which mainly covers the key links such as monofilament drawing, monofilament annealing, conductor stranding, insulation extrusion, cable forming and shielding, sheath injection molding, inspection and packaging.
1. Monofilament drawing
Step description: Monofilament drawing is the first step in the production of wires and cables, that is, the raw materials (such as copper, aluminum and other metal bars) are continuously stretched through the wire drawing machine, so that the cross-sectional area is reduced and the length is increased, so as to obtain the metal wire that meets the requirements. The key to this step is to control the diameter, roundness and surface quality of the drawing.
Equipment required: wire drawing machine, heat treatment furnace, etc.
2. Monofilament annealing
Step description: Drawn metal wire usually affects its further processing performance and electrical properties due to work hardening, so it needs to be annealed. During the annealing process, the wire is heated to a certain temperature and then cooled slowly to eliminate internal stress, restore the softness and toughness of the material, and improve the conductivity.
Equipment required: annealing furnace, cooling device, etc.
3. Conductor stranding
Step description: In order to meet the requirements of the cable for current transmission capacity, it is necessary to twist multiple annealed monofilaments into a conductor according to a certain direction, pitch and twisting angle. This process improves the mechanical strength and flexibility of the conductor and reduces the risk of breakage that can occur due to bending of the cable during use.
Equipment required: conductor stranding machine, pressing device, etc.
4. Insulation extrusion
Step description: Insulation extrusion is to wrap the molten plastic (such as polyvinyl chloride PVC, polyethylene PE, etc.) on the periphery of the conductor through the extruder to form a continuous insulation layer. This process requires precise control of extrusion temperature, speed, and pressure to ensure that the insulation is uniform in thickness and free of bubbles and cracks.
Equipment required: extruder, cooling water tank, tractor, etc.
5. Cabling and shielding
Step description: Cable formation is the process of twisting multiple insulated cores into a cable core in a certain way to improve the overall mechanical strength and anti-external interference ability of the cable. Subsequently, shielding layers such as braided mesh or foil + braided mesh can be added as needed to reduce electromagnetic interference (EMI) and radio frequency interference (RFI).
Equipment required: cable forming machine, braiding machine, shielding winding machine, etc.
6. Sheath injection molding
Step description: Sheath injection molding is to wrap a layer of plastic sheath around the cable after it has been cabled and (possibly) shielded to protect the internal structure of the cable from the erosion and mechanical damage of the external environment. This process also requires precise control of injection temperature, pressure and speed to ensure that the jacket fits the cable tightly and is free of gaps and defects.
Equipment required: injection molding machine, cooling device, etc.
7. Inspection and packing
Step description: The manufactured wires and cables need to go through strict inspection procedures, including visual inspection, electrical performance testing, mechanical performance testing, etc., to ensure that the products meet relevant standards and customer requirements. After passing the inspection, it is packed for transportation and storage.
Required equipment: testing instruments (such as voltage testing machines, resistance testers, etc.), packaging machines, warehouse facilities, etc.
To sum up, the manufacturing of plastic wires and cables is a complex process involving multiple links, each of which needs to be precisely controlled and strictly managed to ensure the quality and performance of the final product.
