Design, construction and evaluation of a fiber extracting machine from Calotropis (milkweed) stems

Due to many advantages, natural fibers have been of great interest recently in many researches and industries. Calotropis stem has valuable fibers with various applications in the industry. Regarding this; a fiber extracting machine is designed and constructed, based on mechanical method. The machine performance is evaluated in this research as well. The machine consists of three separation units and two feeding units. Each separation unit is comprised of; a frame, a pair of blades, a pair of roller, two yoke and power transmission system. Some physical and mechanical properties of stems and barks are determined as predesigning steps. Analyzing extracting efficiency at three speed levels and two moisture contents shows that the maximum extracting efficiency (with 98%) is at rotational velocity of 40 rpm with the moisture content of 75% w.b. Experimental test shows that maximum consumed power was about 958 W while whole stem is located in the machine. The capacity of extraction machine based on dried mass of barks and fibers was 2 kg/h approximately.