The paper presents a comprehensive study of the surfaces of plastic samples (90% polysulfone (PSU) + 10% polycarbonate (PC)) modified with the help of an ultrasonic resonator to reduce friction in contact between the material of aluminum skins and a covering puncheon. Comparative characteristics of surfaces have been obtained. such as: microhardness. coefficient of friction and wear r... https://lecoureures.shop/product-category/course-a-pied-accessoires-hydratation-sac-a-dos/