Effect of The Screw-Barrel Clearance and The Cooling Fan on Non-Wheat Noodle Extruder Performance

This research was related to the development of technology for making non-wheat noodles. The process of making non-wheat noodles requires special treatment because of their different characteristics from wheat noodles. One solution that can be used is extrusion technology. Therefore, a single-screw extruder with a small capacity was developed which is expected to meet the needs of SMEs producing non-wheat noodles. This technology is supposed to be capable of supporting an industry based on the utilization of local raw materials, hence enhancing economic growth and sustainable development. Extruder design parameters should be adapted to the dough characteristics; thus, an experimental investigation was done to determine the appropriate design. The first design extruder needed fixing. Dough backflow occurred during the extrusion process, resulting in blocked dough feeding. The wide clearance between the screw and the barrel caused the dough to backflow. Because of friction in the process, a poorly controlled working temperature raised the temperature continually. The poorly controlled working temperature caused an overheated and puffed product. The second design extruder had the clearance smaller, with the size of 0.5 mm, had the die equipped with a breaker plate, and complemented with the cooling fan. The experimental investigation included extruder performance in throughput, energy consumption, operating temperature stability, and noodle quality at various screw rotational speeds. The screw rotational speed was set by setting the inverter at the operation frequency, which resulted in the screw rotational speed of 30 and 40 rpm. The optimum screw rotational speed was resulting the highest noodles throughput with the specific energy consumption (SEC) lower than the other screw rotational speed. The result indicated that the smaller screw-barrel clearance could minimize the backflow, and the cooling fan could maintain the working temperature, so the product puffing could be prevented, and noodle quality was better, but the specific energy consumption was higher than the previous one.