Active Control of Reactive Resin Flow in a Vacuum Assisted Resin Transfer Molding (VARTM) Process

Light Resin Transfer Molding (LRTM) is a variation of the conventional manufacturing process known as Resin Transfer Molding (RTM). In general terms, these manufacturing processes consist of a closed mould with a preplaced fibrous preform through which a polymeric resin is injected, filling the mold completely, producing parts with complex geometries (in general) and good finish. Those processes differ, among other aspects, in the way that injection occurs. In the RTM process the resin is injected through discrete points whereas in LRTM it is injected into an empty channel (with no porous medium) which surrounds the entire mold perimeter. There are several numerical studies involving the RTM process but LRTM has not been explored enough by the scientific community. Based on that, this work proposes a numerical model developed in the FLUENT package to study the resin flow behavior in the LRTM process. Darcy’s law and Volume of Fluid method (VOF) are used to treat the interaction between air and resin during the flow in the porous medium, i.e. the mold filling problem. Moreover, two three-dimensional geometries were numerically simulated considering the RTM and LRTM processes. It was possible to note the huge differences about resin flow behavior and filling time between these processes to manufacture the same parts.

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Similarity Relations of Resin Flow in Resin Transfer Molding Process

Advanced Composite Materials ◽

10.1163/156855109x428745 ◽

2009 ◽

Vol 18 (2) ◽

pp. 135-152 ◽

Cited By ~ 2

Author(s):

Moon-Kwang Um ◽

Joon-Hyung Byun ◽

Isaac M. Daniel

Keyword(s):

Resin Transfer Molding ◽

Resin Flow ◽

Molding Process ◽

Transfer Molding ◽

Similarity Relations

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Feedback control of the vacuum-assisted resin transfer molding (VARTM) process

10.1117/12.339956 ◽

1999 ◽

Cited By ~ 8

Author(s):

Dirk Heider ◽

A. Graf ◽

Bruce K. Fink ◽

John W. Gillespie, Jr.

Keyword(s):

Feedback Control ◽

Resin Transfer Molding ◽

Transfer Molding ◽

Vartm Process

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NUMERICAL ANALYSIS OF INFUSION STRATEGIES IN VACUUM ASSISTED RESIN TRANSFER MOLDING (VARTM) PROCESS

International Journal of Modern Manufacturing Technologies ◽

10.54684/ijmmt.2021.13.3.117 ◽

2021 ◽

Vol 13 (3) ◽

pp. 117-124

Author(s):

Himanshu V. Patel ◽

◽

Harshit K. Dave ◽

Keyword(s):

Resin Transfer Molding ◽

Mold Filling ◽

Vital Role ◽

Simulation Approach ◽

Gating System ◽

Composite Manufacturing ◽

Transfer Molding ◽

Filling Stage ◽

Filling Time ◽

Vartm Process

The Liquid composite Molding (LCM) process, such as Vacuum Assisted Resin Transfer Molding (VARTM), offers a fast and high-quality production of composites laminates. In the VARTM process, the simulation tool is found beneficial to predict and solve composite manufacturing issues. The part quality is dependent on the resin mold filling stage in the VARTM process. The infiltration of resin into a porous fibrous medium is taken place during the resin mold filling stage. The permeability has a crucial role during the resin mold filling stage. In this study, simulation of resin infusion through multiple injection gates is discussed. The various infusion schemes are simulated to identify defect-free composite manufacturing. The simulation approach is applied to five different stacking sequences of reinforcements. In this transient simulation study, permeability and resin viscosity is essential inputs for the resin flow. The simulation approach found that a gating scheme plays a vital role in mold filling time and defect-free composite fabrication. It is found that the line gating system can be useful for fast mold filling over the point gating system.

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A Semi-Analytical Model to Predict Infusion Time and Reinforcement Thickness in VARTM and SCRIMP Processes

Polymers ◽

10.3390/polym11010020 ◽

2018 ◽

Vol 11 (1) ◽

pp. 20 ◽

Cited By ~ 9

Author(s):

Felice Rubino ◽

Pierpaolo Carlone

Keyword(s):

Resin Transfer Molding ◽

Resin Flow ◽

Liquid Composite Molding ◽

Molding Process ◽

Transfer Molding ◽

Deformable Porous Media ◽

Filling Time ◽

Composite Molding ◽

Fabric Deformation ◽

Porosity And Permeability

In liquid composite molding processes, such as resin transfer molding (RTM) and vacuum assisted resin transfer molding (VARTM), the resin is drawn through fiber preforms in a closed mold by an induced pressure gradient. Unlike the RTM, where a rigid mold is employed, in VARTM, a flexible bag is commonly used as the upper-half mold. In this case, fabric deformation can take place during the impregnation process as the resin pressure inside the preform changes, resulting in continuous variations of reinforcement thickness, porosity, and permeability. The proper approach to simulate the resin flow, therefore, requires coupling deformation and pressure field making the process modeling more complex and computationally demanding. The present work proposes an efficient methodology to add the effects of the preform compaction on the resin flow when a deformable porous media is considered. The developed methodology was also applied in the case of Seeman’s Composite Resin Infusion Molding Process (SCRIMP). Numerical outcomes highlighted that preform compaction significantly affects the resin flow and the filling time. In particular, the more compliant the preform, the more time is required to complete the impregnation. On the other hand, in the case of SCRIMP, the results pointed out that the resin flow is mainly ruled by the high permeability network.

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EVALUATION OF MECHANICAL PROPERTIES OF CFRP BY VARTM AND ITS APPLICATION

International Journal of Modern Physics B ◽

10.1142/s0217979206040556 ◽

2006 ◽

Vol 20 (25n27) ◽

pp. 3896-3901 ◽

Cited By ~ 2

Author(s):

YUN-HAE KIM ◽

JIN-HO SON ◽

BYUNG-KUN CHOI ◽

YOUNG-DAE JO ◽

KUK-JIN KIM ◽

...

Keyword(s):

Mechanical Properties ◽

Physical Properties ◽

Resin Transfer Molding ◽

Mechanical Tests ◽

Resin Content ◽

Automobile Engine ◽

Transfer Molding ◽

Mechanical And Physical Properties ◽

Physical Tests ◽

Vartm Process

In the present study, we contrast the change of mechanical and physical properties between VaRTM (Vacuum Assisted Resin Transfer Molding) and hand lay-up process. In the results of mechanical tests, VaRTM specimen is stronger than hand lay-up specimen and hand lay-up specimen became delamination. In the results of physical tests, the resin content of VaRTM specimen is lower than hand lay-up specimen. On micrograph, the strength of specimen by VaRTM between fiber and resin is stronger than that of one by hand lay-up. And the specimen by hand lay-up contains more defects than one by VaRTM. So, VaRTM process can practically apply for automobile engine hood. This paper shows that VaRTM process is one of the most suitable processes for composite parts of automobile.

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