Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Analysis of injection molding process of plastic propeller fan based on the Robust Design method
Submission Author:
Gabriela Buzzi , SC , Brazil
Co-Authors:
Gabriela Buzzi, Diogo Lôndero Da Silva
Presenter: Gabriela Buzzi
doi://10.26678/ABCM.COBEM2021.COB2021-0341
Abstract
Despite the wide use of polymers in the production of industrial components, it is observed that the natural dimensional variability of this type of material is difficult to control. In a large number of applications, this characteristic can compromise the final performance of the product. For this reason, different techniques are employed to minimize the negative effects of the dimensional variability, among them, the Robust Design, also known as Taguchi Method, stands out. The Robust Design method assists in the development of products and processes capable of reducing the undesired effect of noise. These noises are usually present in the operating conditions of the product or process and the variability of its components. In this work, the Robust Design method will be used to reduce the variability of an injection molding process of plastic propeller fan. Based on a preliminary investigations of the rejection rates, it was observed that 94.0% of the problems were associated with propeller unbalance. Thus, the Robust Design method was employed to identify the factors of the injection molding process responsible for this problem and to determine their effects on the process. During the experimental work, 4 parameters of the injection molding process were investigated. The melt temperature ranging between 250 ºC and 280 ºC, injection time ranging between 3 s and 4 s, cooling time ranging between 17 s and 19 s and hold pressure ranging between 91 and 93 bar. A vibration meter equipment was used to measure the vibration of the fans with the collected propellers, where the maximum acceptable value of vibration displacement was assumed to be 0.30 mm. Different combinations of the factors were investigated in three production batches, with thirty samples in each batch. Based on the experimental results, the signal-to-noise ratio was evaluated to identify the factors levels that reduced the process variability by 88% and the rejection rate by 100%.
Keywords
Taguchi method, Plastic injection molding, Process variability, Propeller fan, robust design
