At present, in the production process of wires and cables, it is necessary to use an extruder to spray insulation on the outside of exposed wires to ensure good insulation properties of the wires and cables. After the extruder sprays the outside of the wire, the surface smoothness and flatness of the insulator often cannot meet the requirements, which leads to difficulties in ink adhesion to the insulator surface during subsequent printing processes on the insulator surface. To improve the surface properties of the insulation on the cable surface, plasma treatment is generally performed on the cable surface. Plasma treatment can modify the surface of polymer materials without changing the inherent properties of the material matrix after treatment. Its modification only occurs on the surface of the material, greatly improving the adhesion of the cable surface and facilitating subsequent printing processes.

Principle of Cable Plasma Processing Machine

Plasma is an ionized gas composed of electrons, positive ions, and neutral particles (including all uncharged particles such as atoms, molecules, and atomic clusters) that are electrically neutral to the outside world. The cable plasma processing machine consists of a plasma generator, gas delivery pipeline, and plasma nozzle. The plasma generator generates high voltage and high frequency energy, which is activated and controlled in the nozzle steel pipe through glow discharge to generate low-temperature plasma. With the help of compressed gas, the equivalent ions are sprayed onto the surface of the wire. The compressed gas can be inert gas (N2, Ar, etc.) or active gas (air, O2, etc.). When plasma meets the surface of a wire, physical and chemical changes occur, causing some molecular chains on the insulation surface of the wire to break and produce some active functional groups, resulting in surface cross-linking. If the compressed gas is an active gas, polar functional groups such as hydroxyl (- OH) and carboxyl (- COOH) will also be introduced, which will change the chemical properties of the cable surface, greatly improve its surface energy, clean the wire surface, and increase the roughness caused by wire surface etching, thereby improving the adhesion performance between the wire surface and the ink.

Plasma treatment has the advantages of good processing uniformity, short action time, high efficiency, simple process, and convenient operation. After plasma treatment, the surface of the cable has better wettability and chemical activity. In the subsequent printing process, the ink can better adhere and spread on the surface of the cable, forming clear, firm, and durable handwriting. The common printing methods include screen printing, inkjet printing, etc. Regardless of which method, the surface of the cable after plasma treatment can significantly improve the printing effect.

The factors that affect the plasma treatment effect include power, treatment time, compressed gas pressure, and the distance between the nozzle and the wire. These parameters can be adjusted during the plasma treatment of cables to achieve different treatment effects.