The Monitoring Method Of The Plastic Injection Molding Process Based On The Mold Cavity Pressure Measurement

Plastic injection molding has the advantages of high producing efficiency, stableproducing equality, easy to mass production and complex product geometries, and thusbecomes the most primary processing techniques in plastic industry. During the process,Mold cavity pressure has been recognized as a critical process parameter for the injectionmolding of high quality plastic parts. Mold cavity pressure sensing technology offers aneffective method to help engineers scientifically analyze the processing procedure.Furthermore, the mold cavity pressure sensing technology can be used in monitoring thefactories producing to enhance the product quality and the capabilities of replication,which brought significant outlook in industry application. Hence, this paper creates anapproach to analyze as well as monitor the plastic injection molding procedure based onthe mold cavity pressure sensing technology.The theory of mold cavity pressure sensing technology is discussed in the chapter two.In order to get the precise data inside the mold during the processing, the research isfocused on the aspects of work principles of the different pressure sensors, the rightplacement in the mold and the establishment of mold cavity pressure controlling system. Atypical mold cavity pressure curve is given as an example to show the sequences toscientifically analyze the processing procedure, including the processing parameters canbe shown on the curve.The characteristics of curve shape are great influence by the processing parameterssetting. Based on the self-developed mold cavity pressure measuring system, this paperchooses4main processing parameters of injection rate, mold temperature, packingpressure and packing time as the experimental factors, and adopt the one-fact completerandomized design method to run the experiments. The influences of processingparameters variation on the curve shape characteristics are summarized based on theexperiments results.In order to realize the injection process monitoring, it is very important to determinethe standard mold cavity pressure curve of high product quality, and the suitable tolerance range of curve shape. This paper proposes a method to find out the standard mold cavitypressure curve based on the produce quality trials, and then discusses the determination oftolerance range of curve shape based on the statistical process control method.According to the above research, this paper discusses the method of monitoring theplastic injection molding procedure based on the mold cavity pressure sensing technology,and gives out some examples about the procedures of processing parameters optimizationused the mold cavity pressure sensing technology.