Amine Catalyst for Refrigerator Rigid Foam Application

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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“…Using the discretized continuity equation (15), the transient terms in Equation (22) can be changed into the following relation:…”

Section: Momentum Equationmentioning

confidence: 99%

“…Arai et al [15] did experiments in which pre-mixed foam reactants were poured into an L-shaped mold, and allowed to ÿll the mold as the mixture foamed and expanded. The distribution of the foam density was then evaluated in the solid part.…”

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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“…A standardized formulation for automotive seating, as shown in Table 2, was employed as a standard system for producing the HR foam samples. The reaction profiles, such as, cream time, gel time and rise time, for each catalyst evaluated, was determined in free rise foam parts by conventional hand mixing method [4]. The concentration of each catalyst was adjusted to give 80 second gel times.…”

Section: Catalytic Activity and Physical Propertiesmentioning

confidence: 99%