Molding simulations

This interplay of the many variables is extremely complex and involves a matrix of the many variables. As an example in the molding simulation TMconcept system programmed Molding Cost Optimization (MCO) of Plastics Computer Inc., Dallas, TX, there are well over 300 variables. It is not reasonable to expect a person using manual methods to calculate these complex interactions even if molding only a modest shaped product without omissions or errors. Computerized process simulation is a practical tool to monitor the influence of design alternatives on the processability of the product and to select molding conditions that ensure the required product quality (3). 

Rheology is a complex subject, and in the formulated colorant industry two simplified approaches have served well in the majority of cases. These are the single-point method, melt flow, and the molding simulation test, spiral flow. 

The advent of high-speed computers, availability of sophisticated algorithms and state-of-the-art computer graphics have made plausible the use of computationally intensive methods such as QM, MM and molecular dynamics (MolD) simulations to determine those physical and structural properties most commonly involved in molecular processes. The power of molecular modeling rests solidly on a variety of well-established scientific disciplines including computer science, theoretical chanistry, biochemistry and biophysics. Molecular modeling has become an indispensable complementary tool for most experimental scientific research. 

Contour plots of the wall thickness distribution for the injection blow molding simulations. 

Injection-molding simulation has a high return on investment. 

In short, compared to other production processes, injection molding demands more of part and mold designers—experimentation after the mold is built is expensive in terms of time and money. Injection-molding simulation is relatively inexpensive in terms of project cost and offers great benefits to those using it early in the manufacturing process. 

We will not discuss the details of simulation for these processes, as many of the fundamental ideas are common to injection-molding simulation. 

Earlier we mentioned that a model exists for injection-molding simulation that allows simulation to be carried out in reasonable time on relatively inexpensive computers. This model is based on the fact that in a thin-walled part we may neglect any pressure variation in the normal direction. This assumption underlies the basis of most commercial plastic CAE analysis. 

There are three main types of analysis in injection-molding simulation ... 

TABLE 11.3 Data Needed for Injection-Molding Simulation—Simple Mold Filling Analysis of Thermoplastics and Thermoplastic Elastomers... 

TABLE 11.5 Data Needed for Molding Simulation—Mold Filling, Packing, and Cooling Analysis of Reactive Materials Including Thermosets... 

TABLE 11.6 Data Needed for Injection-Molding Simulation—Additional Data for Shrinkage and Warpage Analysis ... 

The individual costs of generating material data needed for performing injection-molding simulation, including advanced shrink-age/warpage analysis (Table 11.26), comes to almost 8400 compared to a discounted price of 3000 to 4000 for group tests offered by some of the independent laboratories. 

TABLE 11.26 Individual Costs of Generating Data Needed for Injection-Molding Simulation... 

Simpol, Molding simulation and flow analysis, part quoting, Injection Molding Industries... 

D QuickFill, Desktop molding simulation solids-based, C-MOLD... 

TMcmicept, Injection molding simulation software system. Plastics Computer Inc. 

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