Plasma Surface Modification of Aircraft Tire Cords for Enhanced Adhesive Properties With Rubber

ABSTRACT Why can nylon 66 serve as an ideal reinforcement material for aircraft tires? Polyamide 66 (PA66) is extensively utilized in aircraft tires because of its superior properties, including high tensile strength, wear resistance, heat resistance, and impact resistance. These characteristics significantly increase the tire's capacity to endure substantial rated loads, intense impact energies, considerable deflections, and high‐temperature environments. However, PA66 has relatively low surface inertness, which results in poor interfacial adhesion with rubber. To address this, adhesive impregnation is commonly employed to improve bonding; nonetheless, challenges persist, such as the detachment of fiber cords from the rubber film and inadequate adhesion, leading to insufficient H pull‐out force. In this study, plasma treatment was applied for fiber surface modification before adhesive impregnation, with the goal of enhancing the bonding performance between the rubber matrix and PA66. The influence of various plasma processing parameters—including power, speed, and fiber twist level—on the performance of PA66 fiber cords was systematically investigated. The findings indicate that when the fiber twist level is 230, the processing power is 150 W, and a treatment speed of 5 mm/s is utilized, the highest H pull‐out force is 286 N, representing a 38% improvement in comparison with that of untreated fibers. Therefore, plasma surface modification is a promising technique for achieving enhanced interfacial PA66‐rubber adhesion, demonstrating its excellent promise for application in the manufacture of aircraft tires.