A simplified chemorheological model of viscosity evolution for solvent containing resol resin in RTM process

2017 ◽  
Vol 134 (36) ◽  
pp. 45282 ◽  
Author(s):  
Xiaolin Yi ◽  
Xiao Kuang ◽  
Lei Kong ◽  
Xia Dong ◽  
Zhihai Feng ◽  
...  
Keyword(s):  

2011 ◽  
Vol 236-238 ◽  
pp. 241-246 ◽  
Author(s):  
Yuan Bo Huang ◽  
Zhi Feng Zheng ◽  
Hao Feng ◽  
Hui Pan

The resol-type resin was prepared with a high yield from the liquefied products of walnut shell in phenol, which was reacted with formaldehyde under low alkaline conditions. The effects of reaction temperature and time on the yield and viscosity of the resol resin were investigated. Results showed that the optimum resol resinification conditions were a reaction temperature of 80°C and a reaction time of 2 h. The biomass-based resol resin from liquefied products of walnut shell was successfully applied to produce phenolic foam with diisopropyl ether as the blowing agent, Tween 80 as the surfactant and hydrochloric acid as the catalyst, respectively. The obtained foams showed satisfactory mechanical properties and a uniform fine cellular structure.



2010 ◽  
Vol 46 (6) ◽  
pp. 1237-1243 ◽  
Author(s):  
J.C. Domínguez ◽  
M.V. Alonso ◽  
M. Oliet ◽  
E. Rojo ◽  
F. Rodríguez


2000 ◽  
Author(s):  
David Nielsen ◽  
Ranga Pitchumani

Abstract Variabilities in the preform structure in situ in the mold are an acknowledged challenge to effective permeation control in the Resin Transfer Molding (RTM) process. An intelligent model-based controller is developed which utilizes real-time virtual sensing of the permeability to derive optimal decisions on controlling the injection pressures at the mold inlet ports so as to track a desired flowfront progression during resin permeation. This model-based optimal controller employs a neural network-based predictor that models the flowfront progression, and a simulated annealing-based optimizer that optimizes the injection pressures used during actual control. Preform permeability is virtually sensed in real-time, based on the flowfront velocities and local pressure gradient estimations along the flowfront. Results are presented which illustrate the ability of the controller in accurately steering the flowfront for various fill scenarios and preform geometries.



2001 ◽  
Vol 83 (7) ◽  
pp. 1415-1424 ◽  
Author(s):  
Byung-Dae Park ◽  
Bernard Riedl ◽  
Yoon SooKim ◽  
Won Tek So


2021 ◽  
Author(s):  
Jie Wang ◽  
Peng Wang ◽  
Nahiène Hamila ◽  
Philippe Boisse

During the forming stage in the RTM process, deformations and orientations of yarns at the mesoscopic scale are essential to evaluate mechanical behaviors of final composite products and calculate the permeability of the reinforcement. However, due to the high computational cost, it is very difficult to carry out a mesoscopic draping simulation for the entire reinforcement. In this paper, a macro-meso scale simulation of composite reinforcements is presented in order to predict mesoscopic deformations of the fabric in a reasonable calculation time. The proposed multi-scale method allows linking the macroscopic simulation of the reinforcement with the mesoscopic modelling of the RVE through a macromeso embedded analysis. On the base of macroscopic simulations using a hyperelastic constitutive law of the reinforcement, an embedded mesoscopic geometry is first deduced from the macroscopic simulation of the draping. To overcome the inconvenience of the macro-meso embedded solution which leads to unreal excessive yarn extensions, local mesoscopic simulations based on the embedded analysis are carried out on a single RVE by defining specific boundary conditions. Finally, the multi-scale forming simulations are investigated in comparison with the experimental results, illustrating the efficiency of the proposed approach, in terms of accuracy and CPU time.



2009 ◽  
Vol 2 (S1) ◽  
pp. 181-184 ◽  
Author(s):  
D. Soulat ◽  
S. Allaoui ◽  
S. Chatel


2000 ◽  
Author(s):  
Zhongman Ding ◽  
Shoujie Li ◽  
L. James Lee ◽  
Herbert Engelen

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.



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 ◽  
...  

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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