CAE of Mold Cooling in Injection Molding Using a Three-Dimensional Numerical Simulation

1992 ◽  
Vol 114 (2) ◽  
pp. 213-221 ◽  
Author(s):  
K. Himasekhar ◽  
J. Lottey ◽  
K. K. Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Injection Molding ◽  
Cooling System ◽  
Three Dimensional ◽  
Ambient Air ◽  
Injection Molding Process ◽  
Analysis Tool ◽  
Molding Process ◽  
Dimensional Boundary

In recent years, increased attention has been paid to the design of cooling systems in injection molding, as it became clear that cooling affects both productivity and part quality. In order to systematically improve the performance of a cooling system in terms of rapid, uniform, and even cooling, the designer needs a CAE analysis tool. For this, a computer simulation has been developed for three-dimensional mold heat transfer during the cooling stage of an injection molding process. In this simulation, mold heat transfer is considered as cyclic-steady, three-dimensional conduction; heat transfer within the melt region is treated as transient, one-dimensional conduction; heat exchange between the cooling channel surfaces and coolant is treated as steady, as is heat exchange with the ambient air and mold exterior surfaces. Numerical implementation includes the application of a hybrid scheme consisting of a modified three-dimensional, boundary-element method for the mold region and a finite-difference method with a variable mesh for the melt region. These two analyses are iteratively coupled so as to match the temperature and heat flux at the mold-melt interface. Using an example, the usefulness of the simulation developed here in the design of a cooling system for an injection molding process is amply demonstrated.

Computer Simulation of Warpage Formation in Polymer Injection Molding of a Step Pad

2006 ◽  
Author(s):  
Sridhar P. Ramamurthy ◽  
Lyle Steenson ◽  
Zhong Hu
Keyword(s):  
Injection Molding ◽  
Cooling System ◽  
Three Dimensional ◽  
Nonlinear Material ◽  
Injection Molding Process ◽  
Molding Process ◽  
Element Analysis ◽  
Polymer Injection ◽  
Fea Model ◽  
Polymer Injection Molding

Warpage is one of the most common defects of a plastic product in the polymer injection molding process. It is attributed to the differential shrinkage after the part is ejected from the die cavity due to the nonlinear material property of the polymer, improper design of the cooling system, geometry of the part and the related process parameters. In this paper, the warpage formation of a plastic part, Step Pad of polypropylene copolymer, in the cooling stage of the polymer injection molding process was simulated by finite element analysis (FEA). A three-dimensional FEA model, taking into account the nonlinear material (polypropylene copolymer) properties, with a thermal-structural sequential coupled approach of higher computing efficiency was developed. The effects of mold closed time and layout of cooling system on the dimension and shape of the part were investigated. Industrial experiments for the different mold closed times (25s, 30s, 35s, 40s, 45s, 50s, and 55s) were conducted. The simulation results were compared with the experimental results. The approach is effective in predicting warpage in the polymer injection molding processes.

Polypropylene Based Piezo Ceramic Compounds for Micro Injection Molded Sensors

2017 ◽  
Vol 742 ◽  
pp. 807-814 ◽  
Author(s):  
Christoph Doerffel ◽  
Ricardo Decker ◽  
Michael Heinrich ◽  
Jürgen Tröltzsch ◽  
Mirko Spieler ◽  
...  
Keyword(s):  
Injection Molding ◽  
Ceramic Powder ◽  
Three Dimensional ◽  
Conductive Filler ◽  
High Sensitivity ◽  
Injection Molding Process ◽  
Molding Process ◽  
Ceramic Particles ◽  
Wide Range ◽  
Ceramic Compounds

Polymer matrix compounds based on piezo ceramic and electrically conducting particles within a thermoplastic matrix show distinctive piezoelectric and dielectric effects which can used for sensor applications. The electrical and mechanical properties can be adjusted in a wide range by varying the ratio of active filling particles and the matrix materials. The sensor effect of the compound is generated by the ceramic particles. A large ratio of piezo ceramic powder facilitates a high sensitivity. The electrical permittivity of the otherwise insulating matrix polymer can be adjusted by the amount of conductive filler. An aligned permittivity leads to a stronger electrical field in the ceramic particles. In contrast, too many conductive particles create a conductive network in the compound which short-circuits the sensors. The piezo ceramic compounds can be processed via micro injection molding for application as ceramic sensors. This offers a wide range of new sensor design variants, notably three-dimensional and highly complex geometries. However, there are two main demands for a highly sensitive sensor, which are conflicting. On the one hand the filler content of piezo ceramic particles in combination with electrical conductive carbon nanotubes must be very high, on the other hand the wall thickness should be as thin as possible. For filling cavities with a high aspect-ratio in an injection molding process, low viscosity polymer melts are necessary. These process characteristics conflict with the increasing viscosity by filling the melt with the particles. The sensor measuring area has to be designed as thin walled as possible. In order to overcome this obstacle a dynamically tempered mold design is applied to avoid solidification of the melt, before the mold is completely filled. The mold can be tempered by Peltier elements. The fully electric tempering is cleaner, more precise and more reliable than conventional water or oil tempering.

Parallel three-dimensional simulation of the injection molding process

2009 ◽  
Vol 59 (7) ◽  
pp. 801-815 ◽  
Author(s):  
B. J. Araújo ◽  
J. C. F. Teixeira ◽  
A. M. Cunha ◽  
C. P. T. Groth
Keyword(s):  
Injection Molding ◽  
Three Dimensional ◽  
Injection Molding Process ◽  
Molding Process ◽  
Dimensional Simulation

scholarly journals Application of Intelligent Modeling Method to Optimize the Multiple Quality Characteristics of the Injection Molding Process of Automobile Lock Parts

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2515
Author(s):  
Wei-Tai Huang ◽  
Chia-Lun Tsai ◽  
Wen-Hsien Ho ◽  
Jyh-Horng Chou
Keyword(s):  
Temperature Distribution ◽  
Injection Molding ◽  
Process Parameters ◽  
Cooling System ◽  
Injection Molding Process ◽  
Molding Process ◽  
Conformal Cooling ◽  
Characteristic Index ◽  
Average Temperature ◽  
Gray Correlation

This study focuses on applying intelligent modeling methods to different injection molding process parameters, to analyze the influence of temperature distribution and warpage on the actual development of auto locks. It explores the auto locks using computer-aided engineering (CAE) simulation performance analysis and the optimization of process parameters by combining multiple quality characteristics (warpage and average temperature). In this experimental design, combinations were explored for each single objective optimization process parameter, using the Taguchi robust design process, with the L18 (21 × 37) orthogonal table. The control factors were injection time, material temperature, mold temperature, injection pressure, packing pressure, packing time, cooling liquid, and cooling temperature. The warpage and temperature distribution were analysed as performance indices. Then, signal-to-noise ratios (S/N ratios) were calculated. Gray correlation analysis, with normalization of the S/N ratio, was used to obtain the gray correlation coefficient, which was substituted into the fuzzy theory to obtain the multiple performance characteristic index. The maximum multiple performance characteristic index was used to find multiple quality characteristic-optimized process parameters. The optimal injection molding process parameters with single objective are a warpage of 0.783 mm and an average temperature of 235.23 °C. The optimal parameters with multi-objective are a warpage of 0.753 mm and an average temperature of 238.71 °C. The optimal parameters were then used to explore the different cooling designs (original cooling, square cooling, and conformal cooling), considering the effect of the plastics temperature distribution and warpage. The results showed that, based on the design of the different cooling systems, conformal cooling obtained an optimal warpage of 0.661 mm and a temperature of 237.62 °C. Furthermore, the conformal cooling system is smaller than the original cooling system; it reduces the warpage by 12.2%, and the average temperature by 0.46%.

scholarly journals Modeling and Simulation of Fiber Orientation in Injection Molding of Polymer Composites

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Jang Min Park ◽  
Seong Jin Park
Keyword(s):  
Finite Element ◽  
Injection Molding ◽  
Fiber Orientation ◽  
Flow Model ◽  
Three Dimensional ◽  
Coupled Analysis ◽  
Injection Molding Process ◽  
Molding Process ◽  
Orientation Tensor ◽  
Closure Approximations

We review the fundamental modeling and numerical simulation for a prediction of fiber orientation during injection molding process of polymer composite. In general, the simulation of fiber orientation involves coupled analysis of flow, temperature, moving free surface, and fiber kinematics. For the governing equation of the flow, Hele-Shaw flow model along with the generalized Newtonian constitutive model has been widely used. The kinematics of a group of fibers is described in terms of the second-order fiber orientation tensor. Folgar-Tucker model and recent fiber kinematics models such as a slow orientation model are discussed. Also various closure approximations are reviewed. Therefore, the coupled numerical methods are needed due to the above complex problems. We review several well-established methods such as a finite-element/finite-different hybrid scheme for Hele-Shaw flow model and a finite element method for a general three-dimensional flow model.

Analysis and Optimization on Injection Molding Process of Double Helical Gear Based on Moldflow

2015 ◽  
Vol 1096 ◽  
pp. 376-380
Author(s):  
Chang Yong Jiang ◽  
Hong Lei Shen
Keyword(s):  
Numerical Simulation ◽  
Injection Molding ◽  
Simulation Analysis ◽  
Cooling System ◽  
Process Analysis ◽  
Electrical Equipment ◽  
Helical Gear ◽  
Injection Molding Process ◽  
Feed System ◽  
Molding Process

In view of a kind of a plastic double helical gear in some office electrical equipment, injection molding process analysis was done, by means of Moldflow,to create feed system and cooling system for Moldflow analysis of helical gear, to make numerical simulation analysis, verification and optimization of injection molding process, to obtain some major parameters such as temperature, pressure and time to meet molding requirements of injection molding process of double helical gear.

Fabrication of pure aluminum nanowires by using injection molding process in ambient air

2015 ◽  
Vol 148 ◽  
pp. 30-33 ◽  
Author(s):  
Shih-Hsun Chen ◽  
Chiu-Yen Wang ◽  
Yung-Chang Chen ◽  
Chien-Wan Hun ◽  
Shih-Fan Chen ◽  
...  
Keyword(s):  
Injection Molding ◽  
Pure Aluminum ◽  
Ambient Air ◽  
Injection Molding Process ◽  
Molding Process
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