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
2017 ◽  
Vol 742 ◽  
pp. 807-814 ◽  
Author(s):  
Christoph Doerffel ◽  
Ricardo Decker ◽  
Michael Heinrich ◽  
Jürgen Tröltzsch ◽  
Mirko Spieler ◽  
...  

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.


2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Jang Min Park ◽  
Seong Jin Park

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.


Author(s):  
Sridhar P. Ramamurthy ◽  
Lyle Steenson ◽  
Zhong Hu

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.


2007 ◽  
Vol 23 (1) ◽  
pp. 31-39 ◽  
Author(s):  
C.-M. Lin ◽  
T.-C. Lin ◽  
H.-M. Chu ◽  
Y.-L. Chen

AbstractThis paper adopts a three-dimensional (3D) finite element method to simulate the injection molding of organic 3D stacked-chip assemblies. The geometry model of the assembly is simplified to a five-layered structure of stacked-chips with no solder bumps. The injection molding process incorporates 3D stacked-chip packaging and encapsulation techniques, and comprises primarily of multi-layer cavity-filling and reactive-thermosetting curing processes. The current investigation considers the effects of specifying different entrances on the resultant flow fronts, air-traps, and weld-lines. In general, the present results confirm the value of performing numerical simulations of the 3D stacked-chip packaging process to support the injection molding CAE approaches which are commonly applied nowadays to improve the packaging assembly design and to facilitate the rapid set up of mass-production conditions. The simulation results indicate that the best packaging results are obtained when the melt is introduced either at the center of the periphery side of the stacked-chip modulus or at its corner.


2012 ◽  
Vol 472-475 ◽  
pp. 2859-2863
Author(s):  
Guang Si Luo

The crux to the 3D design of cavity of injection molds for involute plastic gears is to solve the difficulty in zooming the cavity of molds and the accurate molding of the involute tooth profile. Researches have shown that the shrinkage of involute tooth profile is non-linear during the injection molding process of plastic gears. This paper presents the 3D design of cavity of injection molds for involute gears based on SolidWorks after offering an introduction to the relationship between the cavity tooth profile of injection molds for small-modulus plastic gears and the tooth profile of injection molding part.


1992 ◽  
Vol 114 (2) ◽  
pp. 213-221 ◽  
Author(s):  
K. Himasekhar ◽  
J. Lottey ◽  
K. K. Wang

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.


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