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Resin Viscosity (resin + viscosity)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Influence of resin viscosity and vacuum level on mechanical performance of sandwich structures manufactured by vacuum bagging

ADVANCES IN POLYMER TECHNOLOGY, Issue 1 2010
A. Valenza
Abstract The choice of process parameters is critical in optimizing the mechanical properties of sandwich structures produced using the vacuum bagging technique. The aim of this paper is to analyze how the viscosity of the resin/curing agent system and the vacuum level influence the morphology and the mechanical behavior of sandwich beams with composite faces (epoxy resin and glass fiber fabric named COMBI 900) and a PVC foam core. Four different sandwich structures were produced by varying the viscosity of the epoxy resin/curing agent at constant maximum vacuum pressure. Three further structures were manufactured by varying the strength of the vacuum with the resin viscosity maintained constant at the minimum level. Three point bending tests were carried out on all seven sandwiches. The analysis shows that although both parameters affect the mechanical characteristics of the structure, the viscosity of the resin system is clearly the more influential of the two. The morphological structure of the sandwiches was analyzed both by scanning electron microscope (SEM) and by muffle furnace ignition to calculate the percentage of fibers, matrices, and voids present in the different samples © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:20,30, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20172 [source]

Reactive mold filling in resin transfer molding processes with edge effects

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2009
Yanyu Ding
Abstract Reactive mold filling is one of the important stages in resin transfer molding processes, in which resin curing and edge effects are important characteristics. On the basis of previous work, volume-averaging momentum equations involving viscous and inertia terms were adopted to describe the resin flow in fiber preform, and modified governing equations derived from the Navier,Stokes equations are introduced to describe the resin flow in the edge channel. A dual-Arrhenius viscosity model is newly introduced to describe the chemorheological behavior of a modified bismaleimide resin. The influence of the curing reaction and processing parameters on the resin flow patterns was investigated. The results indicate that, under constant-flow velocity conditions, the curing reaction caused an obvious increase in the injection pressure and its influencing degree was greater with increasing resin temperature or preform permeability. Both a small change in the resin viscosity and the alteration of the injection flow velocity hardly affected the resin flow front. However, the variation of the preform permeability caused an obvious shape change in the resin flow front. The simulated results were in agreement with the experimental results. This study was helpful for optimizing the reactive mold-filling conditions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]

Modeling and simulation approaches in the resin transfer molding process: A review

POLYMER COMPOSITES, Issue 4 2003
A. Shojaei
A review of current approaches in modeling and simulation of the resin transfer molding (RTM) process is presented. The processing technology of RTM is discussed and some available experimental techniques to monitor the process cycle are presented. A master model is proposed for the entire process cycle consisting of mold filling and curing stages. This master model contains the fundamental and constitutive sub-models for both stages. The key elements of the master model discussed in this study are: flow, heat and mass balance equations for fundamental sub-models, permeability, cure kinetics, resin viscosity and void formation for constitutive sub-models. At the end, numerical methods widely used to simulate the filling process are presented and published simulation results of mold filling and process cycle are reviewed. [source]