End-Point Control of Holding Phase Based on Cavity Pressure for Injection Molding

2011 ◽  
Vol 221 ◽  
pp. 333-337
Author(s):  
Jian Wang ◽  
Peng Cheng Xie ◽  
Wei Min Yang
Keyword(s):  
Injection Molding ◽  
Control Method ◽  
Holding Time ◽  
Control Mode ◽  
Cavity Pressure ◽  
End Point ◽  
Sensor Position ◽  
Molded Parts ◽  
Point Control

While the switchover from filling to packing is particularly crucial during injection molding, the transfers from holding to screw recovery also significantly affects the quality of molded parts. In this study, the end-point control of the holding phase based on cavity pressure was presented. It was compared with the traditional control method by holding time. The purpose of this study was to validate the feasibility of the end-point control of holding phase by cavity pressure, and to examine its consistency. The weight of the molded parts served as the main measure to probe the process’s capabilities. The results of the verification experiments revealed that the end-point control mode based on cavity pressure could yield better consistency of part weight than the traditional control method by holding time, however, the benefits were not significant. The trigger value of cavity pressure and sensor position should be considered for achieving such high process capabilities.

Study on the End-Point Control of Holding Phase during Injection Molding

2009 ◽  
Vol 87-88 ◽  
pp. 222-227 ◽  
Author(s):  
Jian Wang ◽  
Peng Cheng Xie ◽  
Yu Mei Ding ◽  
Wei Min Yang
Keyword(s):  
Injection Molding ◽  
Mold Temperature ◽  
Control Methods ◽  
Cavity Pressure ◽  
Precise Control ◽  
End Point ◽  
Control Change ◽  
Molded Parts ◽  
Point Control ◽  
Product Weight

While the transfer from filling to packing is particularly crucial during injection molding, the transfers from packing to holding and holding to screw recovery also significantly affect part quality. In this study, the control of the transfer from holding to screw recovery, that is the control of the end-point of the holding phase, was examined. The holding end-point control by time, cavity pressure and cavity temperature were presented. The purpose of this study was to validate the feasibility of the control methods of holding end-point by cavity pressure and cavity temperature. The qualities of injection-molded parts, weight, will serve as measures to probe their process capabilities. Recently found to be a good indicator of product quality, both cavity pressure and temperature profiles are applied here to obtain more precise control. Change of mold temperature was specially considered. After the experimental verification is conducted, the results reveal that the innovative holding end-point control by cavity temperature yields a more uniform product weight with mold temperature. It proved that the holding end-point control by cavity temperature can be used to obtain the optimum holding time and accommodate the product weight to the change of mold temperature, which is the other holding control methods cannot obtain.

Filling-to-Packing Switchover Mode Based on Cavity Pressure for Injection Molding

2012 ◽  
Vol 501 ◽  
pp. 168-173 ◽  
Author(s):  
Jian Wang
Keyword(s):  
Injection Molding ◽  
Crucial Role ◽  
Mold Temperature ◽  
The Other ◽  
Injection Time ◽  
Cavity Pressure ◽  
Part Quality ◽  
Molded Parts ◽  
Screw Position

Filling-to-packing switchover control during injection molding plays a crucial role in ensuring the quality of the molded parts. In this study, a filling-to-packing switchover mode based on cavity pressure was presented, and it was compared with other two switchover modes by injection time and screw position. The objective of this study was to validate the accuracy of the switchover mode based on cavity pressure, and examine its consistency. Weight of the molded parts served as the main measure to probe the process capabilities. In this study, the change in mold temperature was monitored; variation of mold temperature affecting the process was examined. The results of the verification experiments revealed that the switchover mode based on cavity pressure could yield a better part quality and consistent part weight compared with the other two traditional switchover modes. It was proved that the switchover mode by cavity pressure can be used to improve the precision of the injection molding. However, a suitable switchover pressure must be used for achieving such high process capability, and the position to get the pressure signal and mold temperature should also be considered.

scholarly journals Tie-Bar Elongation Based Filling-To-Packing Switchover Control and Prediction of Injection Molding Quality

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1168 ◽  
Author(s):  
Jian-Yu Chen ◽  
Chun-Ying Liu ◽  
Ming-Shyan Huang
Keyword(s):  
Injection Molding ◽  
Pressure Sensors ◽  
Clamping Force ◽  
Cavity Pressure ◽  
Testing Specimen ◽  
Injection Speed ◽  
Novel Approach ◽  
Pressure Profiles ◽  
Molded Parts ◽  
Short Shot

Filling-to-packing switchover (also called V/P switchover) is critical for assuring injection molding quality. An improper V/P switchover setting may result in various defects of injection-molded parts, such as excessive residual stress, flash, short shot, and warpage, etc. To enhance a consistent molding quality, recent V/P switchover approaches adopt cavity pressure profiles requiring sensors embedded in mold cavities, which is invasive to mold cavities and more expensive. Instead of using cavity pressure sensors, by working with the most popular screw position switchover control, this study hereby proposes a novel approach of tuning V/P switchover timing using a tie-bar elongation profile. In this investigation, a dumbbell testing specimen mold is applied to verify the feasibility of the method proposed. The results show that the mold filling and packing stages can be observed along the tie-bar elongation profile, detected by mounting strain gauges on the tie bars. Also, the characteristics of the cavity pressure are similar to those of the tie-bar elongation profile under a proper clamping force condition. Moreover, the varying process parameter settings which include injection speed, V/P switchover point, and holding pressure, can be reflected in these profiles. By extracting their characteristics, the application of the V/P switchover is proved to be realistic. This research conducted an experiment to verify the proposed V/P switchover decision method based on the tie-bar elongation profile. The result showed that the fluctuation of the part’s weight corresponding to a slight change of the barrel’s temperature from 210 °C to 215 °C can be successfully controlled with this method. Besides, the maximum clamping force increment extracted from the tie-bar elongation profile was found to be a good indicator for online monitoring of the reground material variation.

Study of the Structural Characteristics of Mold for Precise Injection Molding

2011 ◽  
Vol 291-294 ◽  
pp. 610-613
Author(s):  
Hong Lin Li ◽  
Zhi Xin Jia
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Structural Characteristics ◽  
Injection Mold ◽  
Industrial Products ◽  
Balance System ◽  
Molded Parts ◽  
Manufacturing Accuracy ◽  
Injection Molded

With the improvement of accuracy requirements for industrial products, the precise injection molding is replacing the traditional injection molding quickly and widely. Many factors influence the quality of injection-molded parts greatly, such as the property of the plastics, mold structure and the manufacturing accuracy, injecting machine and the injecting process parameters. In this paper, the work is emphasized for the influence of mold structure on the quality of injection-molded parts. Eight portions of injection mold are analyzed, including the cavities and cores, the guide components, the runner system, the ejection system, the side-core pulling mechanism, the temperature balance system, the venting system and the supporting parts. The structural characteristics of the above eight portions are presented.

The Deformation Analysis and Optimization of the Injection Molded Parts Based on the Moldflow and Minitab Software

2013 ◽  
Vol 753-755 ◽  
pp. 1180-1183 ◽  
Author(s):  
Na Li ◽  
Hong Bin Liu ◽  
Hai Tao Wu
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Optimization Design ◽  
Deformation Analysis ◽  
Molded Parts ◽  
Injection Molded ◽  
The Common ◽  
Plastic Parts ◽  
Cae Technology

The deformation seriously affects the quality of the products, which is one of the common defects of plastic parts in the injection molding. Factorial design and CAE technology was used to study the product's warping rate influence in this paper. The minimum warping rate was obtained through the Minitab software and the optimized process parameters are verified with the Moldflow software. Experimental results show that the optimization design is effective and the warpage of the product is reduced.

Status Analysis of Quality Prediction for Automotive Injection Molded Parts

2014 ◽  
Vol 998-999 ◽  
pp. 534-537 ◽  
Author(s):  
Chun Neng Wang ◽  
Xi Ying Fan
Keyword(s):  
Injection Molding ◽  
Coupling Effect ◽  
Kriging Model ◽  
Development Trend ◽  
Quality Prediction ◽  
Molded Parts ◽  
Injection Molded ◽  
Status Analysis ◽  
The Development Trend

Injection molding is a very complex multi-factor coupling effect and a nonlinear dynamic process. Therefore, under the influence of nonlinear and multi-factor, injection molding goal is to effectively predict and guarantee the quality of injection molded parts. In this paper, the common methods used to predict the quality of injection molded parts are introduced, including: Taguchi method, artificial neural network, response surface method, radial basis function method and Kriging model method. Research progresses as well as application examples of forecasting methods at home and abroad is summarized. Besides, the development trend of the injection molding quality prediction is discussed.

Influence of Injection Molding Parameters on the Consistency of Molding Process

2013 ◽  
Vol 446-447 ◽  
pp. 398-402
Author(s):  
S. Azmoudeh ◽  
H. Zamani ◽  
K. Shelesh-Nezhad
Keyword(s):  
Injection Molding ◽  
Signal To Noise Ratio ◽  
Injection Molding Process ◽  
Process Conditions ◽  
Cavity Pressure ◽  
Molding Process ◽  
Injection Speed ◽  
Taguchi Design Of Experiments ◽  
Pressure Profiles ◽  
Molded Parts

The existence of variations in the injection molding process conditions leads to the inconsistency of molded parts quality during the molding cycles. In this research, the variations of cavity pressure-time profiles integrals over the molding cycles were accounted as the molded parts quality variations. Thereafter, the correlations between injection molding process settings and the degree of consistency of molding process were investigated by applying cavity pressure measurement, Taguchi design of experiments approach and signal to noise ratio. The results derived from experiments indicated that an increase approximately as high as five times in the capability of injection molding may be achieved. Under the best setting condition, the cavity pressure profiles were relatively smooth and similar. Low screw rotational speed, high injection speed and short packing time led to the inconsistency elevation of injection molding.

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