Development of Cotton Candy Method for High Productivity Polypropylene Fibers Webs

The cotton candy method (CoCAM) is developed for high productivity of polymer micro-and nano-fibers. Polypropylene was molten in a single screw extruder of the CoCAM at air pressures of 0.2-0.5 MPa with nozzle temperatures of 280-350 °C and the constant air temperature of 600 °C. The distance from the nozzle to the collector was set at 10-90 cm. Thermal images informed the accumulation of PP fibers flows at shorter collector distance. The diameters of PP micro-fibers decreased with increasing the air pressures and the nozzle temperatures. Crystallinity of the PP micro-fibers increased when increasing the nozzle temperature due to higher occasion of molecular orientation. The degree of the fiber entanglement in the PP micro-fibers decreased when increasing the collector distance, which affected on the declination of tensile strength. Ductility of the PP micro-fibers improved at high collector distances. The optimum condition of the PP micro-fibers was found at the average diameter of 2.3 μm at 0.5 MPa with the nozzle temperature of 340 oC collected at 60 cm. The productivity of the PP micro-fibers webs from the CoCAM was 144 g/h.