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.

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

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 20 ◽  
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.

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.

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

Aerospace ◽  
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.

Determination of the Thermal Dispersion Coefficient During Radial Filling of a Porous Medium

2003 ◽  
Vol 125 (5) ◽  
pp. 875-880 ◽  
Author(s):  
Mylene Deleglise ◽  
Pavel Simacek ◽  
Christophe Binetruy ◽  
Suresh Advani
Keyword(s):  
Porous Media ◽  
Dispersion Coefficient ◽  
Resin Transfer Molding ◽  
Liquid Composite Molding ◽  
Thermal Dispersion ◽  
Transfer Molding ◽  
Thermoset Resin ◽  
Composite Molding ◽  
Fibrous Porous Media

Resin Transfer Molding is one of the Liquid Composite Molding processes in which a thermoset resin is infiltrated into a fibrous porous media in a closed mold. To reduce the curing time of the resin, the mold may be heated, influencing other filling parameters such as the resin viscosity. Analysis of the non-isothermal effects during filling will help to understand the manufacturing process. One of the issues of non-isothermal filling in porous media is the variation of the velocity profile at the micro scale level, which as it is averaged, cannot be included in the convective term. To account for it, the thermal conductivity tensor is modified and a thermal dispersion coefficient Kd is introduced to model the micro convection effects. In this paper, we explore the temperature profile under non-isothermal conditions for radial injection during Resin Transfer Molding in order to determine the thermal dispersion coefficient. An approximate solution is derived from the series solution and validated with a numerical method. Experiments using carbon fibers and polyester resin were conducted. The thermal dispersion coefficient is determined by comparing experimental results with the steady state analytical solution. The comparison between radial and linear injection results shows that the same degree of dispersion is present in isotropic fibrous porous media.

scholarly journals Mold Filling Simulation of Resin Transfer Molding Combining BEM and Level Set Method

2011 ◽  
Vol 62 ◽  
pp. 57-65 ◽  
Author(s):  
Renaud Gantois ◽  
Arthur Cantarel ◽  
Gilles Dusserre ◽  
Jean Noel Félices ◽  
Fabrice Schmidt
Keyword(s):  
Level Set ◽  
Resin Transfer Molding ◽  
Mold Design ◽  
Liquid Composite Molding ◽  
Two Dimensional ◽  
Dimensional Approach ◽  
Present Contribution ◽  
Transfer Molding ◽  
Composite Molding ◽  
Filling Simulation

Liquid Composite Molding (LCM) is a popular manufacturing process used in many industries. In Resin Transfer Molding (RTM), the liquid resin flows through the fibrous preform placed in a mold. Numerical simulation of the filling stage is a useful tool in mold design. In this paper the implemented method is based on coupling a Boundary Element Method (BEM) with a Level Set tracking. The present contribution is a two-dimensional approach, decoupled from kinetics, thermal analysis and reinforcement deformation occurring during the flow. Applications are presented and tested, including a flow close to industrial conditions.

Relaxation-Compression Resin Transfer Molding under Magnetic Field

2020 ◽  
Vol 847 ◽  
pp. 81-86
Author(s):  
Ahmed Ouezgan ◽  
Said Adima ◽  
Aziz Maziri ◽  
El Hassan Mallil ◽  
Jamal Echaabi
Keyword(s):  
Magnetic Field ◽  
Volume Fraction ◽  
Resin Transfer Molding ◽  
Molding Process ◽  
Fiber Volume ◽  
Transfer Molding ◽  
Resin Impregnation ◽  
New Variant ◽  
New Process ◽  
Compression Resin Transfer Molding

Relaxation-compression resin transfer molding under magnetic field is a new variant of VARTM (“vacuum assisted resin transfer molding”) process, which uses a flexible magnetic membrane controlled by a magnetic force, in order to govern the relaxation and compression phases by changing the permeability of the fabric preform. Thus permits to the resin to enter easily into the mold and to increase the resin impregnation velocity and the fiber volume fraction. This innovation is based on the application of the TRIZ theory (“the theory of inventive problem solving”), which allows us to answer to the shortcomings and the conflict links exist inside the VARTM processes. The objective of this paper is to present this new process and to study the effect of the current intensity and the separated gap between the flexible magnetic membrane and solenoid on the permeability of the preform.

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.

Optical measurement of local permeability of flax fiber fabrics before liquid composite molding

2018 ◽  
Vol 52 (24) ◽  
pp. 3289-3297 ◽  
Author(s):  
Benoît Cosson
Keyword(s):  
Optical Method ◽  
Fiber Volume Fraction ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Optical Measurement ◽  
Transmission Measurement ◽  
Liquid Composite Molding ◽  
Fiber Volume ◽  
Filling Time ◽  
Composite Molding

Tracking the variability of natural fiber-based fabrics properties, such as local areal weight, fiber volume fraction, and therefore permeability, is crucial to optimize the parts processing of the bio-composites. This paper aims at developing a cost-effective and efficient optical method in order to predict the permeability of flax fabrics used in liquid composite molding processes. This method using an LCD monitor as light source and a reflex camera as a measurement device is based on light transmission measurement through fabric thickness. The raw data given by the camera are gray scale maps, transformed into areal weight maps. FEM software based on levelset method is finally used to highlight the influence of the local variability of the fiber volume fraction, and of the related fabrics porosity and permeability on the mold filling time. The proposed method can be directly implemented on the manufacturing line of the composites. It can be used to optimize, part-to-part, the resin consumption by predicting the resin flow through perform. Interestingly, this novel optical method is auto-calibrated and does not depend on picture resolution.

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.

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