Overview of Power Cord Manufacturing

Manufacturing a high-quality power cord involves multiple precise processes, each requiring specialized equipment and skilled operators. From raw copper wire to the finished, tested cord set ready for shipment, every step contributes to the final product’s safety, reliability, and performance. Zhejiang Jinting Nuclear Cable Co., Ltd. operates fully integrated manufacturing facilities covering the complete power cord production process.

Step 1: Raw Material Inspection and Procurement

Quality begins with raw materials. Copper conductors are sourced from certified suppliers and verified for purity (typically 99.9% minimum), correct gauge, and strand count. PVC and rubber compounds are tested for electrical properties (resistivity, dielectric strength), mechanical properties (tensile strength, elongation), and thermal properties (temperature rating verification). Plug and connector components (brass pins, plastic housings) are dimensionally inspected against specifications with complete material traceability maintained throughout production.

Step 2: Cable Production (Extrusion)

At Jinting, flexible cables are produced through extrusion. Copper conductors are drawn and stranded to the specified cross-section and flexibility class. For PVC cables, PVC compound is extruded over each conductor as insulation, then multiple insulated conductors are cabled together, and an outer PVC sheath is extruded over the cabled core. For rubber cables, rubber compounds are extruded and then vulcanized (cross-linked) through a continuous vulcanization process. Throughout, on-line monitoring checks insulation thickness, concentricity, and surface quality. Spark testing detects any insulation defects immediately after extrusion.

Step 3: Cable Cutting and Stripping

Finished cables are cut to specified lengths using automated cutting machines that cold-cut or hot-cut with precise length control (typically ±5mm or better). The ends are then automatically stripped to the correct length, removing the outer jacket to expose the individual insulated conductors, and stripping the conductor insulation to expose the bare copper for termination. Our automated stripping machines ensure consistent strip lengths critical for proper termination in the subsequent processes.

Step 4: Terminal Attachment

Depending on the plug/connector type: for injection-molded plugs, the stripped conductors are inserted directly into the plug mold; for mechanical assembly, terminals or contacts are crimped or soldered to the conductors, then assembled into plug/connector housings. Crimping quality is critical—each crimp must achieve proper mechanical grip and electrical conductivity. Our automated crimping presses apply controlled force and verify crimp height for each terminal.

Step 5: Injection Molding

Injection molding is the critical process where the plug or connector body is formed around the cable end. Precisely positioned conductors are placed in a mold, heated PVC or other thermoplastic is injected under high pressure filling the mold cavity, the material cools and solidifies forming the complete plug body with integrated strain relief, and the molded assembly is ejected and trimmed. Key process parameters include injection temperature, injection pressure, mold temperature, cooling time, and holding pressure. At Zhejiang Jinting Nuclear Cable Co., Ltd., injection molding is performed under tightly controlled conditions to ensure consistent quality, proper conductor positioning, and reliable strain relief in every molded termination.

Step 6: Testing and Quality Control

Every power cord undergoes 100% electrical testing including hi-pot (dielectric withstand) test typically at 1500-2500V AC for 1-60 seconds, ground continuity test for 3-wire cords (resistance typically < 0.1 ohm), and polarity verification to ensure correct conductor-to-pin mapping. Sampling tests include pull-force testing on molded plugs, flexing endurance tests, temperature rise under rated load, and full compliance verification to applicable standards. Only cords passing all tests proceed to packaging.

Step 7: Printing, Packaging, and Shipment

Qualified cords receive identification printing (manufacturer, ratings, certifications, traceability codes). They are then coiled/formed to specified configuration, packaged per customer requirements (bulk, individual bag, retail packaging), labeled with required information, packed in export-quality cartons, and prepared for shipment through Ningbo or Shanghai ports. Every carton is labeled with product details, quantity, production batch, and destination information for full supply chain traceability.