scholarly journals Optimizing Bladder Resin Transfer Molding Process to Manufacture Complex, Thin-Ply Thermoplastic Tubular Composite Structures: An Experimental Case Study

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4093
Author(s):  
Somen K. Bhudolia ◽  
Pavel Perrotey ◽  
Goram Gohel ◽  
Sunil C. Joshi ◽  
Pierre Gerard ◽  
...  
Keyword(s):  
Process Parameters ◽  
Composite Structures ◽  
Resin Transfer Molding ◽  
Low Permeability ◽  
Molding Process ◽  
Mechanical Fracture ◽  
Transfer Molding ◽  
Injection Process ◽  
Liquid Injection

The bladder molding process is primarily used in sporting applications but mostly with prepregs. Bladder-Assisted Resin Transfer Molding (B-RTM) presents the tremendous potential to automate and mass produce the complex hollow-composite profiles. Thin-ply, non-crimp fabrics (NCFs) provide excellent mechanical, fracture toughness, and vibration damping properties on top of the weight saving it offers to a final product. However, these fiber architectures are difficult to inject due to the resistance they provide for the polymer flow using the liquid injection process. Therefore, it is mandatory to optimize the process parameters to reduce the time for injection and simultaneously achieve better consolidation. This work presents a first, detailed, experimental case study to successfully inject a low-permeability, thin-ply, complex, thermoplastic tubular structure, and the effect of process parameters, boundary conditions, the associated manufacturing challenges, and proposed solutions are deliberated in this paper.

Multiconstraint Optimization of Composite Structures Manufactured by Resin Transfer Molding Process

2005 ◽  
Vol 39 (4) ◽  
pp. 347-374 ◽  
Author(s):  
Chung Hae Park ◽  
Woo Il Lee ◽  
Woo Suck Han ◽  
Alain Vautrin
Keyword(s):  
Composite Structures ◽  
Resin Transfer Molding ◽  
Molding Process ◽  
Transfer Molding

A new methodology for race-tracking detection and criticality in resin transfer molding process using pressure sensors

2018 ◽  
Vol 52 (29) ◽  
pp. 4087-4103 ◽  
Author(s):  
Nihad A Siddig ◽  
Christophe Binetruy ◽  
Elena Syerko ◽  
Pavel Simacek ◽  
Suresh Advani
Keyword(s):  
Pressure Gradient ◽  
Resin Transfer Molding ◽  
Pressure Sensors ◽  
General Rule ◽  
Cost Effective ◽  
Flow Patterns ◽  
Manufacturing Strategy ◽  
Molding Process ◽  
Transfer Molding ◽  
Injection Process

In this study, a simplified cost effective simulation-based methodology is proposed to assist manufacturing engineers in the design and development phase of the resin transfer molding process. Race-tracking is unavoidable in the resin transfer molding and can lead to entrapment of air pockets, which results in parts being discarded as scrap. A purely numerical methodology is presented to distinguish between the critical and non-critical race-tracking scenarios, that will guide the design and production engineers plan an efficient and effective manufacturing strategy. The detection methodology is based on computing the pressure evolution with time during the injection process. The novelty relies on the superimposition of the computed pressure gradient maps that reveals unsuspected common features in the numerous race-tracking cases investigated in the various geometries of increasing complexity considered. The pressure sensors are meant to detect and evaluate different race-tracking scenarios and their level of criticality. The minimum number and locations of pressure sensors arise directly from the highest pressure gradient zones for simple geometries. Sensors placement guidelines are introduced for a simple rectangular shape, then this information is used to qualitatively apply the guidelines to parts of more complex shapes. A general rule that all parts, no matter how complex, can be considered as a combination of simpler ones is presented. Furthermore, a new failure criterion is proposed based on the flow patterns that highlights the likely flow patterns to entrap voids.

Use of Resin Transfer Molding Simulation to Predict Flow, Saturation and Compaction in the VARTM Process

2002 ◽  
Author(s):  
N. C. Correia ◽  
F. Robitaille ◽  
A. C. Long ◽  
C. D. Rudd ◽  
P. Sˇima´cˇek ◽  
...  
Keyword(s):  
Resin Transfer Molding ◽  
Molding Process ◽  
Transfer Molding ◽  
Injection Process ◽  
Software Packages ◽  
Compaction Force ◽  
Thickness Variations ◽  
Filling Simulation ◽  
Complex Parts ◽  
Vartm Process

Vacuum Assisted Resin Transfer Molding (VARTM) and Resin Transfer Molding (RTM) are among the most significant and widely used Liquid Composite manufacturing processes. In RTM preformed-reinforcement materials are placed in a mold cavity, which is subsequently closed and infused with resin. RTM numerical simulations have been developed and used for a number of years for gate assessment and optimization purposes. Available simulation packages are capable of describing/predicting flow patterns and fill times in geometrically complex parts manufactured by the resin transfer molding process. Unlike RTM, the VARTM process uses only one sided molds (tool surfaces) where performs are placed and enclosed by a sealed vacuum bag. To improve the delivery of the resin, a distribution media is sometimes used to cover the preform during the injection process. Attempts to extend the usability of the existing RTM algorithms and software packages to the VARTM domain have been made but there are some fundamental differences between the two processes. Most significant of these are 1) the thickness variations in VARTM due to changes in compaction force during resin flow 2) fiber tow saturation, which may be significant in the VARTM process. This paper presents examples on how existing RTM filling simulation codes can be adapted and used to predict flow, thickness of the preform during the filling stage and permeability changes during the VARTM filling process. The results are compared with results obtained from an analytic model as well as with limited experimental results. The similarities and differences between the modeling of RTM and VARTM process are highlighted.

Manufacturing Fiber-Reinforced Polymer Composite Using RTM Process: An Analytical Approach

2017 ◽  
Vol 380 ◽  
pp. 60-65 ◽  
Author(s):  
M.J. do Nascimento Santos ◽  
A.G. Barbosa de Lima
Keyword(s):  
High Performance ◽  
Separation Of Variables ◽  
Resin Transfer Molding ◽  
Surface Finishing ◽  
Constant Thickness ◽  
Molding Process ◽  
Transfer Molding ◽  
Dimensional Precision ◽  
Good Surface ◽  
Injection Process

The Resin Transfer Molding process (RTM) has been widely used for manufacturing of high performance components in aerospace and automotive industries. It is an economical and faster method when compared to open molding process because it allows the molding of complex parts with constant thickness, dimensional precision, good surface finishing and an excellent control of mechanical properties. In this sense, this work aims to study theoretically the manufacture process of polymeric composites reinforced with fibers via resin transfer molding. The governing equations of conservation of mass and momentum, and Darcy's law are presented, and the exact solution of the problems is obtained via method of separation of variables. Predicted results of the flow front and the pressure fields of the resin inside the model during the injection process are presented, compared with experimental data and analyzed. It was verified a good agreement between the results.

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.

Development of resin transfer molding process using scaling down strategy

2013 ◽  
Vol 35 (9) ◽  
pp. 1683-1689 ◽  
Author(s):  
Raghu Raja Pandiyan Kuppusamy ◽  
Swati Neogi
Keyword(s):  
Resin Transfer Molding ◽  
Molding Process ◽  
Transfer Molding ◽  
Scaling Down

scholarly journals Resin transfer molding process: a numerical and experimental investigation

2013 ◽  
Vol 7 (2) ◽  
pp. 125-136 ◽  
Author(s):  
Iran de Oliveira ◽  
Sandro Amico ◽  
Jeferson Souza ◽  
Antonio de Lima
Keyword(s):  
Experimental Investigation ◽  
Resin Transfer Molding ◽  
Molding Process ◽  
Transfer Molding

A Closed Form Solution for Flow During the Vacuum Assisted Resin Transfer Molding Process

1999 ◽  
Vol 122 (3) ◽  
pp. 463-475 ◽  
Author(s):  
K-T. Hsiao ◽  
R. Mathur ◽  
S. G. Advani ◽  
J. W. Gillespie, ◽  
B. K. Fink
Keyword(s):  
Closed Form ◽  
Scaling Laws ◽  
Resin Transfer Molding ◽  
Closed Form Solution ◽  
Form Solution ◽  
Flow Front ◽  
Molding Process ◽  
Transfer Molding ◽  
Front Region ◽  
Insight Into

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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