Braiding techniques were often kept secret and detailed instruction about it was rarely described in the documents. Therefore, braiders needed to accumulate experience and cultivate own skill by learning through trial and error. The expert unconsciously used braiding technique learned from substantial experience. In this paper, specific behavior to the expert was investigated. And then, coaching comment of the expert was analyzed to figure out how they determine subject’s skill and transfer their own implicit knowledge. It was found that the complicated movement of fingers is one of the specific behavior to the expert and they coach the subject by explaining the differences from their movement. The difference between the expert and subject is identified by deriving from a feeling of strangeness against the subject’s behavior.

The structures and properties of para-aramid yarn were investigated under different treatment temperatures from 80 °C to 200 °C with supercritical CO₂ and air, respectively, which were observed by Scanning electron microscopy (SEM), Dynamic wetting measurements, Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), and Thermogravimetric instrument (TG). It is confirmed that the surface morphology of para-aramid yarn was changed remarkably with the supercritical CO₂ treatment temperature increasing compared to untreated yarn and treated with air, and the oligomers and disaggregates of yarn were migrated to the yarn surface. Furthermore, the water contact angle of para-aramid was reduced significantly from 136.22° to 91.37° with supercritical CO₂ treatment at 200 °C, and the wettability was improved. Overall, supercritical CO₂ modification for para-aramid has been proved to be feasible.