Three‐dimensional modeling of reaction injection molding. I

Lo, Yu‐Wen; Reible, Danny D.; Collier, J. R.; Chen, Cheng‐Ho

doi:10.1002/pen.760341805

Cited by 11 publications

(7 citation statements)

References 11 publications

(2 reference statements)

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“…These values are less than analytical ÿlling times of 8.667 and 2:639 s, respectively, because some air is trapped behind the insert. Also, the cells near the boundary are not ÿlled completely because the critical fractional volume value f c , which is used for switching the boundary condition from tractionfree to no-slip, is 0.9 in our case (see Equations (13) and (14)).…”

Section: Mold ÿLlingmentioning

confidence: 99%

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Numerical simulation of mold filling in foam reaction injection molding

Seo

Youn

Tucker

2003

Numerical Methods in Fluids

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SUMMARYA numerical simulation of reaction injection molding (RIM) of polymeric foam is developed, using a ÿnite volume method (FVM). In this study we predict mold ÿlling with a variable-density uid that ÿlls a mold by self-expansion. We deal with two-dimensional, isothermal cases. With the assumptions of ideal mixing and rapid bubble nucleation, the foam is modelled as a continuum with a time-dependent density. The continuum is assumed to be a Newtonian uid. We develop a pressure-based FVM for unstructured meshes that includes the SIMPLE algorithm with treatment of uid compressibility. Cellbased, co-located storage is used for all physical variables. To treat the moving interface, an explicit high-resolution interface capturing method is used. Foam ow in a slit is investigated, and the numerical calculations are in good agreement with an approximate analytic solution. For fountain ow in a rectangular cavity, the shape of the ow front is atter and the traces of the particles are more complicated for an expanding foam than for a constant-density uid. An example of mold ÿlling by an expanding foam demonstrates the geometric exibility of the method.

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Section: Mold ÿLlingmentioning

confidence: 99%

“…For this reason, there have been few studies reported on FRIM. There have been some numerical simulations of the RIM process [10][11][12][13][14]. In these studies, numerical methods similar to those used for injection molding were used to simulate the process.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of mold filling in foam reaction injection molding

Seo

Youn

Tucker

2003

Numerical Methods in Fluids

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“…In addition, the model assumes that the formed chain from each reaction step is not involved in further reactions. Although this kind of model has been suggested by some researchers [32][33][34][35][36], the applicability is limited due to the complex nature of the reaction and the multiple phases that the reacting thermoset goes through.…”

Section: Kinetic Calculationmentioning

confidence: 99%

Experimental modeling of the cure behavior of a formulated blend of DGEBA epoxy and C12-C14 glycidyl ether as a reactive diluent

Ali

Hammami

2005

Polym. Compos.

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Microwave curing of polymer matrix composites has been suggested as an attractive substitute for conventional thermal curing. Formulations of epoxy and reactive diluents have the advantage of better wettability and uniform fiber impregnation. However, higher peak exotherms in large masses, and thus thermal overshoot, presents a challenge for cure cycle optimization. Therefore, building a reliable curing model will not only predict the behavior of these materials during actual processing, but also facilitate numerical modeling of the process and comparison of other resin formulations. In this study the effect of the reactive diluent on the isothermal cure kinetics of low viscosity epoxy was investigated using differential scanning calorimetry (DSC). A formulated blend of diglycidyl ether of bisphenol A (DGEBA) and C 12 -C 14 aliphatic glycidyl was cured using diethylene triamine as the curing agent. Using a standardized procedure, ISO 113571-5, the epoxy formulation was isothermally cured at several temperatures and the heat flow monitored and recorded. Using the heat flow data from DSC, the rate of cure was determined experimentally and a proper autocatalytic model with a total order of about 2.3 was fit to describe the process. Leastsquare regression and isoconversion methods were used to find the model parameters and the activation energy, respectively. The accuracy of the model shows fine correlation with experimental data. By comparison to other epoxy resin without diluents, the analysis of the data shows that the reactive diluent increased the curing rate, while the values of activation energy and process parameters remained within the typical values of epoxy formulations. Based on these data, the future use of these types of resins in nonthermal curing of epoxy matrix composites is discussed. POLYM. COMPOS., 26: 593-603, 2005.

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“…This is determined by the initial chemical recipe (i.e., isocyanate, polyol, and blowing agents structure and concentration, catalyst and surfactant type and concentration), the injection dynamics and the flow history of the foam into the mold. However, the relationship between the process conditions and the final foam characteristics is highly empirical, and the development of mathematical models is identified as the most efficient way to establish a more reliable and quantitative approach to the problem …”

Section: Introductionmentioning

confidence: 99%

“…However, the relationship between the process conditions and the final foam characteristics is highly empirical, and the development of mathematical models is identified as the most efficient way to establish a more reliable and quantitative approach to the problem. [5][6][7][8][9][10][11][12] Our objective is to develop a three-dimensional model, based on computational fluid dynamics (CFD), capable of simulating the mold filling process. The model also incorporates a population balance equation (PBE) that describes the evolution of the BSD due to bubble growth, caused in turn by physical and chemical blowing agents, and bubble coalescence, caused by shear-induced bubble collisions.…”

Section: Introductionmentioning

confidence: 99%

A Baseline Model for the Simulation of Polyurethane Foams via the Population Balance Equation

Karimi

Marchisio

2015

Macro Theory & Simulations

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In this work, a novel approach, based on the population balance equation (PBE), is presented and applied for the first time to the simulation of expanding polyurethane foams. The solution of the PBE allows to determine the evolution of the bubble size distribution (BSD) of the foam, which in turn defines the mechanical and thermal properties. The approach includes a kinetic model for the polymerization and blowing reactions, accounts for the presence of a physical blowing and for the total energy balance. Model predictions are compared with experiments from the literature for 12 different chemical recipes, highlighting acceptable agreement.

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Three‐dimensional modeling of reaction injection molding. I

Cited by 11 publications

References 11 publications

Numerical simulation of mold filling in foam reaction injection molding

Numerical simulation of mold filling in foam reaction injection molding

Experimental modeling of the cure behavior of a formulated blend of DGEBA epoxy and C12-C14 glycidyl ether as a reactive diluent

A Baseline Model for the Simulation of Polyurethane Foams via the Population Balance Equation

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