Flow front measurements and model validation in the vacuum assisted resin transfer molding process

A closed form solution to the flow of resin in vacuum assisted resin transfer molding process (VARTM) has been derived. VARTM is used extensively for affordable manufacturing of large composite structures. During the VARTM process, a highly permeable distribution medium is incorporated into the preform as a surface layer. During infusion, the resin flows preferentially across the surface and simultaneously through the preform giving rise to a complex flow front. The analytical solution presented here provides insight into the scaling laws governing fill times and resin inlet placement as a function of the properties of the preform, distribution media and resin. The formulation assumes that the flow is fully developed and is divided into two regimes: a saturated region with no crossflow and a flow front region where the resin is infiltrating into the preform from the distribution medium. The flow front region moves with a uniform velocity. The law of conservation of mass and Darcy’s Law for flow through porous media are applied in each region. The resulting equations are nondimensionalized and are solved to yield the flow front shape and the development of the saturated region. It is found that the flow front is parabolic in shape and the length of the saturated region is proportional to the square root of the time elapsed. The results thus obtained are compared to data from full scale simulations and an error analysis of the solution was carried out. It was found that the time to fill is determined with a high degree of accuracy while the error in estimating the flow front length, d, increases with a dimensionless parameter ε=K2xxh22/K2yyd2. The solution allows greater insight into the process physics, enables parametric and optimization studies and can reduce the computational cost of full-scale 3-dimensional simulations. A parametric study is conducted to establish the sensitivity of flow front velocity to the distribution media/preform thickness ratio and permeabilities and preform porosity. The results provide insight into the scaling laws for manufacturing of large scale structures by VARTM. [S1087-1357(00)02002-5]

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A flow-front refinement technique for the numerical simulation of the resin-transfer molding process

Composites Science and Technology ◽

10.1016/s0266-3538(99)00029-9 ◽

1999 ◽

Vol 59 (11) ◽

pp. 1663-1674 ◽

Cited By ~ 39

Author(s):

M Kang

Keyword(s):

Numerical Simulation ◽

Resin Transfer Molding ◽

Flow Front ◽

Molding Process ◽

Transfer Molding

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Numerical Analysis of the Resin Transfer Molding Process via PAM-RTM Software

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.365.88 ◽

2015 ◽

Vol 365 ◽

pp. 88-93 ◽

Cited By ~ 3

Author(s):

I.R. Oliveira ◽

Sandro Campos Amico ◽

J.A. Souza ◽

Antônio Gilson Barbosa de Lima

Keyword(s):

Room Temperature ◽

Polyester Resin ◽

Resin Transfer Molding ◽

Injection Pressure ◽

Flow Front ◽

Molding Process ◽

Transfer Molding ◽

Front Profile ◽

Flat Flow ◽

Half Length

This work aims to investigate the infiltration of a CaCO3filled resin in fibrous porous media (resin transfer molding process) using the PAM-RTM software. A preform of glass fiber mat (fraction 30%), with dimensions 320 x 150 x 3.6 mm, has been used in rectilinear injection experiments conducted at room temperature and injection pressure 0.25, 0.50 and 0.75 bar. The polyester resin contain 0% and 40% CaCO3. The numerical results were evaluated by direct comparison with experimental data. The flat flow-front profile of the rectilinear flow was reached approximately half length of the mold. It was observed, that the both velocity infiltration and permeability have decreased with increasing the CaCO3content, thus, increasing the time to processing of the composite material.

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The Thickness and the Inerior Quality of Composite Panel in the Vacuum Assisted Resin Transfer Molding Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.686.468 ◽

2011 ◽

Vol 686 ◽

pp. 468-473

Author(s):

Yan Liang Li ◽

Xiao Su Yi ◽

Bang Ming Tang

Keyword(s):

Fiber Composite ◽

Low Cost ◽

Resin Transfer Molding ◽

Composite Panel ◽

Flow Front ◽

Carbon Fiber Composite ◽

Molding Process ◽

Transfer Molding ◽

Vartm Process

The objective of this paper was focused on predicting the thickness and the interior quality of carbon fiber composite panel during the vacuum assisted resin transfer molding (VARTM) process. The character of the VARTM process determined that it was low cost. A panel made of Epoxy resin, and carbon fibers, was used as the simplest article to experiment and except routine items, the thickness and the interior quality was focused. In the process, the flow front of the resin was record using a digital camera. Darcy’s law was the model of resin flow. The results showed that the flow front history would reach unanimous, thickness near the edges was difficult to control, and most of the porosity came from the injection line where more resin cumulated.

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Correction to: numerical study to control the filler distribution in fibrous media during the particle-filled resin transfer molding process

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-021-07062-x ◽

2021 ◽

Author(s):

Ahmed El Moumen ◽

Abdelghani Saouab ◽

Nihad A. Siddig ◽

Laurent Bizet ◽

Abdellatif Imad

Keyword(s):

Numerical Study ◽

Resin Transfer Molding ◽

Fibrous Media ◽

Molding Process ◽

Transfer Molding ◽

Filler Distribution

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A Conceptional Approach of Resin-Transfer-Molding to Rosin-Sourced Epoxy Matrix Green Composites

Aerospace ◽

10.3390/aerospace8010005 ◽

2020 ◽

Vol 8 (1) ◽

pp. 5

Author(s):

Sicong Yu ◽

Xufeng Zhang ◽

Xiaoling Liu ◽

Chris Rudd ◽

Xiaosu Yi

Keyword(s):

Composite Laminates ◽

Resin Transfer Molding ◽

High Viscosity ◽

Ramie Fiber ◽

Liquid Composite Molding ◽

Curing Agent ◽

Molding Process ◽

Transfer Molding ◽

Low Viscosity ◽

Composite Molding

In this concept-proof study, a preform-based RTM (Resin Transfer Molding) process is presented that is characterized by first pre-loading the solid curing agent onto the preform, and then injecting the liquid nonreactive resin with an intrinsically low viscosity into the mold to infiltrate and wet the pre-loaded preform. The separation of resin and hardener helped to process inherently high viscosity resins in a convenient way. Rosin-sourced, anhydrite-cured epoxies that would normally be regarded as unsuited to liquid composite molding, were thus processed. Rheological tests revealed that by separating the anhydrite curing agent from a formulated RTM resin system, the remaining epoxy liquid had its flowtime extended. C-scan and glass transition temperature tests showed that the preform pre-loaded with anhydrite was fully infiltrated and wetted by the liquid epoxy, and the two components were diffused and dissolved with each other, and finally, well reacted and cured. Composite laminates made via this approach exhibited roughly comparable quality and mechanical properties with prepreg controls via autoclave or compression molding, respectively. These findings were verified for both carbon and ramie fiber composites.

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