Study of an Online Monitoring Adaptive System for Injection Molding Process Based on Nozzle Pressure Curve

Abstract

Injection molding is a popular process for mass production of polymer products but due to the characteristics of the injection process there are many factors that will affect product quality in long fabrication processes Therefore it is critical to find the parameters most highly related to products and to use adaptive adjustment systems to control these parameters In this study product weight is defined as product quality where the purpose of the system is to maintain variations in the product weight Based on the literature review and the preliminary experiment it was found that the peak pressure and viscosity index have a strong relationship with product weight This relationship can be used to obtain the master curve that can be used in the adaptive adjustment system In this study the relationship between product weight and specific parameters were used to build an adaptive adjustment system and the master curve obtained from the preliminary experiment was used to be the algorithm of the system if the quality of the product is qualified the parameter will not change; if the quality is unqualified then the system will adjust the correct injection speed and switchover position to machine depending on the master curve With this system an injection molding machine can sustain good quality during long fabrication processes In this thesis a comparison of the experiment results is used to prove that the proposed system can effectively and correctly adjust the injection speed and switchover position and can monitoring pressure data only depending on the nozzle pressure sensor With this system the coefficient of variation of product weight can be decreased to 0 05%

Date of Award	2020
Original language	English
Supervisor	Sheng-Jye Hwang (Supervisor)