Investigation of residual stress behavior in injection-molded parts using numerical simulation
Abstract
Identifying the optimal process parameters was the main objective of the present work which will enhance the operational performance and dimensional stability via examining the growth and development of residual stresses in a PC injection moulded electric switch socket. These residual stresses are affected by a combination of temperature, flow and pressure which are considered during the molding and it helps in the careful evaluation of these parameters. Taguchi L 27 orthogonal array was adopted and numerical simulations were carried in Inspire (Altair) mold to evaluate the effect of different parameters in mold filling, packing, cooling reactions, residual stresses and deformations. Obtained results indicate that mold temperature was the primary determinant in the work carried and mold filling and mold packaging efficiency was found to be increasing by 10% within the range of 353.15 to 393.15 K. Also, residual stresses were found to be decreased by 15% at a moderate temperature of 373.15 K. Meanwhile it is observed that modifications in melt temperature had an effective impact on deformation and increased it from 553.15 k to 593.15 K which resulted in a 22% increased deformation. A normalized melt temperature of 573.15 K resulted in the lowest residual strain, with an 8% reduction due to enhanced flow uniformity. At an intermediate pressure of 150 MPa, residual stress decreased by 5–7% relative to both 100 MPa and 200 MPa, suggesting a nonlinear relationship between injection pressure and residual stress. Peak residual stress was reduced by 23% when the number of cooling channels was increased from 6 to 8, and further improvements were no longer noticeable after that. Results show that with eight cooling channels, an injection pressure of 150 MPa, a mold temperature of 373 K, and a melt temperature of 573 K, PC electrical components experience the least amount of residual stress and deformation possible during processing.