A Study on the Preparation and Performance of Ultrafine Powder Made of Industrial Hemp Degumming Residue.

Industrial hemp, one of the most widely available and extensively produced varieties, generates a substantial amount of waste in the form of hemp cellulose. This study uses a recycling method combining crushing and acid treatment to convert leftover hemp fiber into ultrafine powder. A scanning electron microscope (SEM), an atomic force microscope (AFM), Fourier transform infra-red spectroscopy (FTIR), and X-ray diffraction (XRD) were used to examine the morphology of acid-treated hemp fiber heated to 200 °C and crushed into powder. The decrease in intensity, fiber surface crystalline, and grain size was analyzed. It became apparent that fiber strength decreased, and fiber roughness significantly increased after acid treatment. The degree of crystallinity of the broken fibers decreased significantly. The proposed method was a simple and effective method for converting leftover hemp fiber into ultrafine powder. In approximately 3 to 5 min, about 1 kg of dry ultrafine powder with a particle size of 38.68 μm was produced. This production method will significantly enhance future industrial applications of hemp residue.