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.

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.

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.

scholarly journals Investigation of Product and Process Fingerprints for Fast Quality Assurance in Injection Molding of Micro-Structured Components

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 661 ◽  
Author(s):  
Nikolaos Giannekas ◽  
Per Kristiansen ◽  
Yang Zhang ◽  
Guido Tosello
Keyword(s):  
Quality Control ◽  
Injection Molding ◽  
Quality Data ◽  
Efficient Production ◽  
Short Cycle ◽  
Part Quality ◽  
Molded Parts ◽  
Micro Features ◽  
Product And Process

Injection molding is increasingly gaining favor in the manufacturing of polymer components since it can ensure a cost-efficient production with short cycle times. To ensure the quality of the finished parts and the stability of the process, it is essential to perform frequent metrological inspections. In contrast to the short cycle time of injection molding itself, a metrological quality control can require a significant amount of time and the late detection of a problem may then result in increased wastage. This paper presents an alternative approach to process monitoring and the quality control of injection molded parts with the concept of “Product and Process Fingerprints” that use direct and indirect quality indicators extracted from part quality data in-mold and machine processed data. The proposed approach is based on the concept of product and process fingerprints in the form of calculated indices that are correlated to the quality of the molded parts. A statistically designed set of experiments was undertaken to map the experimental space and quantify the replication of micro-features depending on their position and on combinations of processing parameters with their main effects to discover to what extent the effects of process variation were dependent on feature shape, size, and position. The results show that a number of product and process fingerprints correlate well with the quality of the micro features of the manufactured part depending on their geometry and location and can be used as indirect indicators of part quality. The concept can, thus, support the creation of a rapid quality monitoring system that has the potential to decrease the use of off-line, time-consuming, and detailed metrology for part approval and can thus act as an early warning system during manufacturing.

scholarly journals Optimization of Process Parameters for Vertical-Faced Polypropylene Bottle Injection Molding

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Youmin Wang ◽  
Zhichao Yan ◽  
Xuejun Shan
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Dwell Time ◽  
Optimization Problem ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Orthogonal Test ◽  
Injection Molding Process ◽  
Injection Time ◽  
Melt Temperature

In order to obtain the optimal combination of process parameters for vertical-faced polypropylene bottle injection molding, with UG, the model of the bottle was drawn, and then, one module and sixteen-cavity injection molding system was established and analyzed using Moldflow. For filling and maintaining pressure during the process of infusion bottle injection molding, the orthogonal test table L25 (56) using CAE was designed for injection molding of the bottle, with six parameters such as melt temperature, mold temperature, injection pressure, injection time, dwell pressure, and dwell time as orthogonal test factors. By finding the best combination of process parameters, the orthogonal experiment was completed, the results were analyzed by range analysis, and the order of influence of each process parameter on each direction of optimization was obtained. The prediction dates of the infusion bottle were gained under various parameters, a comprehensive quality evaluation index of the bottle was formulated, and the multiobjective optimization problem of injection molding process was transformed into a single-objective optimization problem by the integrated weighted score method. The bottle parameters were optimized by analyzing the range date of the weighted scoring method, and the best parameter combination such as melt temperature 200°C, mold temperature 80°C, injection pressure 40 MPa, injection time 2.1 S, dwell pressure 40 MPa, and dwell time 40 S was gained.

Effect of Processing Conditions on the Shrinkage and Warpage of Glass Fiber Reinforced PP Using Microcellular Injection Molding

2012 ◽  
Vol 501 ◽  
pp. 294-299 ◽  
Author(s):  
Zhi Bian ◽  
Peng Cheng Xie ◽  
Yu Mei Ding ◽  
Wei Min Yang
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Process Conditions ◽  
Fiber Reinforced ◽  
Injection Speed ◽  
Glass Fiber Reinforced ◽  
Microcellular Injection Molding ◽  
Molded Parts

This study was aimed at understanding how the process conditions affected the dimensional stability of glass fiber reinforced PP by microcellular injection molding. A design of experiments (DOE) was performed and plane test specimens were produced for the shrinkage and warpage analysis. Injection molding trials were performed by systematically adjusting six process parameters (i.e., Injection speed, Injection pressure, Shot temperature, SCF level, Mold temperature, and Cooling time). By analyzing the statistically significant main and two-factor interaction effects, the results showed that the supercritical fluid (SCF) level and the injection speed affected the shrinkage and warpage of microcellular injection molded parts the most.

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.

scholarly journals Recycling of Cooking Oil Waste into Reactive Polyurethane for Blending with Thermoplastic Polyethylene

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Anika Zafiah M. Rus ◽  
N. Syamimi M. Salim ◽  
N. Haiza Sapiee
Keyword(s):  
Injection Molding ◽  
High Density Polyethylene ◽  
Waste Cooking Oil ◽  
The Other ◽  
Processing Temperature ◽  
Mechanical Behaviors ◽  
Melt Mixing ◽  
Cooking Oil ◽  
Better Than

Driven by the need of growing to a more sustainable and environmentally friendly future, this research is started by mixing in-house produced biorenewable polymers (BP) from waste cooking oil with the standard low density polyethylene (LDPE) and high density polyethylene (HDPE) via melt-mixing at low ratios. These mixtures are then compounded via injection molding to produce tensile samples. By using the quality of individual compounds injected, the parameters obtained for all ratios of LDPE/BP were the same with neat LDPE whereas some adjustments were required for the HDPE/BP compounds. The corresponding mechanical behaviors of each ratio were also examined and the results showed that both tensile strength and strain of the LDPE/BP were better than neat LDPE. On the other hand, increasing the BP content in HDPE/BP will increase the toughness of the compound if compared to neat HDPE. Therefore, not only does the presence of BP provide renewable properties, but it also improves the mechanical properties. Moreover, the processing temperature and composition of BP will both influence the quality and mechanical behavior of the product made. Thus, this study may aid any intention on processing these in-house produced polymers by injection molding.

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.

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