Nitrogen has a wide range of applications in industry as an inexpensive and chemically stable inert gas. The wire and cable manufacturing industry has extremely high requirements for the cleanliness and product quality of the production environment. Nitrogen can provide an oxygen-free, dry production atmosphere, which effectively prevents the impact of oxidation and impurities on material properties. We will detail the application of nitrogen in the wire and cable industry, covering multiple scenarios from production and processing to scientific research and testing, while demonstrating the technical advantages of high-performance gas solutions such as nitrogen generators and deep-cooled air separation equipment provided by Shenger Gas (Hong Kong) Co., Ltd.
Nitrogen applications in cable production processes
In process sections such as line insulation layer extrusion, nitrogen is mainly used as a protective gas to provide an inert environment to prevent oxidation and moisture introduction. Common nitrogen application scenarios in cable production include:
- Wire Insulation Extrusion: During the insulation material extrusion stage, the pure nitrogen supplied by the nitrogen generator forms a sealed protective atmosphere around the wire surface, isolating oxygen and moisture. This effectively prevents oxidation or coating defects, ensuring uniform insulation thickness and excellent electrical performance.
- Nitrogen Foaming: In certain high-frequency or communication cables, nitrogen can be injected into molten polyethylene material to achieve physical foaming, forming a fine cellular insulation structure. Such foamed insulation reduces the dielectric constant and loss, improving signal transmission performance.
- Galvanized Wire Cleaning: In cable production, galvanized steel or copper wires are often treated with hot-dip galvanization. After coating, high-pressure nitrogen spray is used to remove residual molten zinc from the wire surface. Nitrogen purging not only aids in cleaning but also helps achieve a more uniform zinc coating, enhancing the wire’s corrosion resistance.
- Conductor Annealing: During the annealing of metal conductors (such as copper or steel wires), nitrogen is introduced into the heating furnace to maintain an inert atmosphere. This environment effectively prevents oxidation at high temperatures, ensuring that the annealed conductors possess excellent electrical conductivity and flexibility.
- Finished Product Packaging and Storage: After production, cables are typically wound and packaged. Before packaging or storage, nitrogen is used to purge the wound cables, replacing the air and moisture inside the packaging. This process maintains an inert atmosphere within the package, greatly reducing the risk of insulation material aging and metal oxidation, ensuring long-term stability and quality of the stored cables.
Atmospheric control of the cross-linking process
During cable cross-linking, nitrogen plays the role of pressurized heat transfer and inert protection. The high-pressure sealed cross-linked tube filled with high-temperature nitrogen gas, in addition to providing uniform heat transfer to the polyethylene insulation layer, is also able to isolate oxygen and avoid oxidation of the insulating material at high temperatures. Usually the nitrogen purity should be kept above 98% and the temperature controlled at about 220°C to ensure sufficient uniformity of the cross-linking reaction. After the cross-linking is complete, nitrogen continues to cycle through the purge of the coil, taking away the generated water vapor and byproducts while working with the cooling system to slowly reduce the cable temperature to a safe range.
Nitrogen Generator and Air Separation Equipment of Shenger Gas (Hong Kong) Co., Ltd
Sheng Er Gas (Hong Kong) Co., Ltd. is committed to providing high-quality nitrogen generation and air separation equipment for the cable manufacturing industry. Among them, the PSA nitrogen generator products (such as model SEN59-300) adopt advanced molecular sieve adsorption technology, enabling continuous and stable production of high-purity nitrogen. Through the PLC automatic control system, precise adjustment of both flow rate and purity can be achieved. The SEN59-300 nitrogen generator delivers 300 Nm³/h of nitrogen with a purity exceeding 99.999%. Users can adjust the gas output according to their needs. The equipment features a compact structure, low operating energy consumption, and outstanding energy-saving performance.
For large-scale production needs, we also offer cryogenic air separation units, such as the SDON-1000 model. This system utilizes multi-stage compression and high-efficiency heat exchange technology to simultaneously and stably produce high-purity nitrogen and oxygen. The SDON-1000 features a vacuum-insulated distillation column that further reduces energy consumption. The entire unit is highly automated, supports remote monitoring, and offers excellent economic performance and reliability — meeting the long-term, continuous nitrogen supply requirements of the wire and cable industry.
Scientific Research and Special Applications
Scientific Research Scenarios: In the field of cable research and testing, nitrogen is also an essential tool. To evaluate the electrical performance and reliability of new insulation materials, researchers often conduct withstand voltage, arc resistance, and dielectric strength tests in a nitrogen environment to eliminate interference from oxygen and moisture. In addition, nitrogen inert atmospheres are commonly used in thermal aging tests — for example, placing insulation materials in a Differential Scanning Calorimeter (DSC) or Thermogravimetric Analyzer (TGA) and heating them under pure nitrogen protection to accurately measure the thermal degradation behavior and lifetime characteristics of the materials.
Special Manufacturing Applications: In addition to cable production, nitrogen can also be applied to other manufacturing processes. For example, laser cutting equipment commonly uses high-purity nitrogen as an assist gas to create an inert cutting environment, reducing oxidation in the cutting zone and helping achieve smooth, oxide-free cut surfaces. At the same time, nitrogen is also widely used in electronics manufacturing and LED fabrication processes as a cleaning, purging, and inerting gas to maintain cleanliness and safety along the production line.
Overall, the application of nitrogen in the wire and cable industry covers multiple levels from production links to scientific research and testing, providing key guarantees for product quality and stability. With its advanced gas equipment and perfect technical services, Shenger Gas (Hong Kong) Co., Ltd. continues to provide customers with high-purity, adjustable-flow nitrogen solutions to help cable enterprises achieve efficient production and technological innovation.
