Research on the Effect of Dielectric Barrier Discharge (DBD) Plasma Remote Treatment on Drag Force of Polyethylene Terephthalate (PET) Yarns in Air Flow with Different Humidities

In this paper, long-lived free radicals in atmospheric-pressure DBD plasma were used to treat PET yarn surface. Subsequently, the drag force of treated yarns in air flow at four humidities (40 ± 3, 50 ± 3, 60 ± 3, 70 ± 3%) was measured. The results suggest that with the increase of flow humidity, the air drag force of untreated yarn decreased while that of plasma-treated ones on average increased gradually. The average growth rates of the drag force under each humidity were 5.33, 7.58, 10.08 and 12.28% respectively. Meanwhile, the air drag force of the yarns treated at different specific input energy (SIE) densities and treatment time varied obviously under different flow humidity. The X-ray photoelectron spectroscopy analysis was performed to characterize the yarn surfaces chemically. The topology and roughness of PET yarns were measured by atomic force microscopy. The tensile test was carried out to characterize the mechanical strength. The ozone, nitrate and nitrite radicals and total organic carbon in tail gas of plasma were also analyzed. The maximal atomic concentration of N element on PET surface could reach 8.0%. The obtained results can improve the understanding of the property of long-lived reactive species from DBD plasma source generated at different SIE and the difference in PET surface etching and modification during remote treatment at different SIE. Moreover, the results also provide an experimental guideline for the improvement of weaving efficiency in air-jet weaving.