Modeling and evaluation of the filling process of vacuum-assisted compression resin transfer molding

2013 ◽  
Vol 33 (3) ◽  
pp. 211-219 ◽  
Author(s):  
Chih-Yuan Chang
Keyword(s):  
Resin Transfer Molding ◽  
Injection Pressure ◽  
Compression Pressure ◽  
Compression Phase ◽  
Transfer Molding ◽  
Resin Injection ◽  
Compression Time ◽  
Filling Time ◽  
Time Injection ◽  
Compression Resin Transfer Molding

Abstract In the present study, a modified vacuum-assisted compression resin transfer molding (VACRTM) process has been developed to reduce the cycling period. The process uses an elastic bag placed between the upper mold and the preform to replace the mobile rigid mold in compression resin transfer molding. During resin injection, the bag is pulled upward by the vacuum applied in between the upper mold and the bag, and a loose fiber stack is then present. Resin is easily injected into the mold. Once enough volume of resin is injected, the compression pressure is applied on the bag, which compacts the preform and drives the resin through the remaining dry preform. Numerical results show that the bag compression phase is much longer than the resin injection one. A multistage compression strategy can be used to control the compression time. Due to inherent process defects, a higher volume of the injected liquid is essential and thus leads to a longer injection and compression phase in order to inject and squeeze the excess resin. The late compression is very slow in draining the residual resin. As compared with resin transfer molding, VACRTM can reduce the mold-filling time/injection pressure.

Compression Resin Transfer Molding Using Inflatable Seals

2021 ◽  
Vol 900 ◽  
pp. 3-8
Author(s):  
Ahmed Ouezgan ◽  
Said Adima ◽  
Aziz Maziri ◽  
El Hassan Mallil ◽  
Jamal Echaabi
Keyword(s):  
Resin Transfer Molding ◽  
Mold Cavity ◽  
Liquid Composite Molding ◽  
Transfer Molding ◽  
Resin Injection ◽  
New Variant ◽  
Filling Time ◽  
Composite Molding ◽  
Fiber Reinforcements ◽  
Compression Resin Transfer Molding

Compression resin transfer molding using inflatable seals is a new variant of LCM (“Liquid composite molding”) processes, which uses the inflatable seals to compress the fiber reinforcements and drive the resin to impregnate the fabric preform, resulting to fill the entire mold cavity. During resin injection, the preform is relaxed. Consequently, the resin enters easily and quickly into the mold cavity. After, the necessary resin is injected into the mold cavity, the compression stage takes place, in a stepwise manner, by swelling the inflatable seals. The objective of this paper is to present this new process and study the effect of the number of inflatable seals on the filling time.

Application of Calcium Carbonate in Resin Transfer Molding Process

2014 ◽  
Vol 353 ◽  
pp. 39-43 ◽  
Author(s):  
Iran Rodrigues de Oliveira ◽  
Sandro Campos Amico ◽  
R. Barcella ◽  
Antônio Gilson Barbosa de Lima
Keyword(s):  
Calcium Carbonate ◽  
Low Cost ◽  
Resin Transfer Molding ◽  
Injection Pressure ◽  
Molding Process ◽  
Transfer Molding ◽  
Industrial Sectors ◽  
Advanced Composite Materials ◽  
Filling Time ◽  
Manufacturing Techniques

Resin Transfer Molding (RTM) is one of the most widely known composite manufacturing techniques of the liquid molding family, being extensively studied and used to obtain advanced composite materials comprised of fibers embedded in a thermoset polymer matrix. Nowadays, RTM is used by many industrial sectors such as automotive, aerospace, civil and sporting equipment. Therefore, the objective of this study is to verify the effect of calcium carbonate mixed in resin in the RTM process. Several rectilinear infiltration experiments were conducted using glass fiber mat molded in a RTM system with cavity dimensions of 320 x 150 x 3.6 mm, room temperature, maximum injection pressure 0.202 bar and different content of CaCO3 (10 and 40%) with particle size of 75μm. The results show that the use of filled resin with CaCO3 influences the preform impregnation during the RTM molding, changing the filling time and flow from position, however it is possible to make the composite with a good quality and low cost.

A Theoretical Analysis on Resin Injection/Compression Molding

2007 ◽  
Vol 334-335 ◽  
pp. 209-212 ◽  
Author(s):  
Akbar Shojaei ◽  
A. Spah
Keyword(s):  
Analytical Solutions ◽  
Mold Filling ◽  
Compression Molding ◽  
Fiber Content ◽  
Flow Front ◽  
Transfer Molding ◽  
Unidirectional Flow ◽  
Resin Injection ◽  
Filling Time ◽  
Injection Compression Molding

In the present investigation, mold filling process of resin injection/compression molding (RI/CM) is compared with resin transfer molding (RTM) for simple mold geometry. To do this, analytical solutions are obtained for RI/CM in unidirectional flow. Based on the analytical solutions, flow front progression and pressure distribution are compared with RTM at different fiber content. The results indicate that the RI/CM reduces the mold filling time significantly, particularly for composite parts with higher fiber content.

Using Computer Simulation as a Process Design Tool for Resin Injection Pultrusion (RIP)

2000 ◽  
Author(s):  
Zhongman Ding ◽  
Shoujie Li ◽  
L. James Lee ◽  
Herbert Engelen
Keyword(s):  
Modeling And Simulation ◽  
Process Design ◽  
Resin Transfer Molding ◽  
Transfer Molding ◽  
Pultrusion Process ◽  
Rtm Process ◽  
Resin Impregnation ◽  
Heating Section ◽  
Resin Injection ◽  
Resin Injection Pultrusion

Abstract Resin Injection Pultrusion (RIP) is a new composite manufacturing process, which combines the advantages of the conventional pultrusion process and the Resin Transfer Molding (RTM) process. It is sometimes referred to the Continuous Resin Transfer Molding (C-RTM) process. The RIP process differs from the conventional pultrusion process in that the resin is injected into an injection-die (instead of being placed in an open bath) in order to eliminate the emission of volatile organic compounds (styrene) (VOC) during processing. Based on the modeling and simulation of resin/fiber “pultrudability”, resin flow, and heat transfer and curing, a computer aided engineering tool has been developed for the purpose of process design. In this study, the fiber stack permeability and compressibility are measured and modeled, and the resin impregnation pattern and pressure distribution inside the fiber stack are obtained using numerical simulation. Conversion profiles in die heating section of the pultrusion die can also be obtained using the simulation tool. The correlation between the degree-of-cure profiles and the occurrence of blisters in the pultruded composite parts is discussed. Pulling force modeling and analysis are carried out to identify the effect on composite quality due to interface friction between the die surface and the moving resin/fiber mixture. Experimental data are used to verify the modeling and simulation results.

scholarly journals COMPUTATIONAL MODELING OF RTM AND LRTM PROCESSES APPLIED TO COMPLEX GEOMETRIES

2012 ◽  
Vol 11 (1-2) ◽  
pp. 93 ◽  
Author(s):  
J. Da S. Porto ◽  
M. Letzow ◽  
E. D. Dos Santos ◽  
S. C. Amico ◽  
J. A. Souza ◽  
...  
Keyword(s):  
Porous Medium ◽  
Flow Behavior ◽  
Resin Transfer Molding ◽  
Three Dimensional ◽  
Complex Geometries ◽  
Resin Flow ◽  
Transfer Molding ◽  
Rtm Process ◽  
General Terms ◽  
Filling Time

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.

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

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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