Multiscale Model of the RTM Process: From Mesoscale Anisotropic Permeability of Woven Structures to Macroscale Resin Impregnation

2021 ◽  
Author(s):  
Yang Xiao ◽  
Junbo Xu ◽  
Min Wang ◽  
Bingyin Wang ◽  
Shaojun Yuan ◽  
...  
Keyword(s):  
Multiscale Model ◽  
Anisotropic Permeability ◽  
Rtm Process ◽  
Resin Impregnation ◽  
Woven Structures

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.

Fabrication of T-Shaped Structural Composite through Resin Transfer Molding

1995 ◽  
Vol 29 (16) ◽  
pp. 2192-2214 ◽  
Author(s):  
Wen-Bin Young ◽  
Min-Te Chuang
Keyword(s):  
Low Cost ◽  
Resin Transfer Molding ◽  
Mold Filling ◽  
Transfer Molding ◽  
Rtm Process ◽  
Resin Impregnation ◽  
Composite Fabrication ◽  
Fiber Reinforcements ◽  
Fiber Materials ◽  
Dry Spot

Resin transfer molding (RTM) combines resin impregnation and composite fabrication in one process. It simplifies the process for composite fabrication and has the advantages of automation, low cost, and versatile design of fiber reinforcements. The RTM process was used in this study to fabricate T-shaped stuctural composites. Edge effects due to the gap between the fiber mats and the mold or the imperfect sealing of the matting mold resulted in edge channeling flows, leading to dry spot enclosure in the composite. It was found that a vacuum in the mold cavity could reduce the size of the dry spot. Proper control or prevention of the edge flows will reduce the possibility of dry spot formation. Numerical simulations of the mold filling were conducted to study the effect of gate locations on the mold filling patterns and edge channeling flows. Mechanical pulling tests were conducted to investigate the joint strengths of the T-shaped structure for different fiber materials. Fiber stitching on the rib provided an improvement in the joint strength while different fiber materials without fiber stitching tended to have the same joint strengths.

Cross-sectional monitoring of resin impregnation using an area-sensor array in an RTM process

2012 ◽  
Vol 43 (4) ◽  
pp. 695-702 ◽  
Author(s):  
Ryosuke Matsuzaki ◽  
Seiji Kobayashi ◽  
Akira Todoroki ◽  
Yoshihiro Mizutani
Keyword(s):  
Sensor Array ◽  
Cross Sectional ◽  
Rtm Process ◽  
Resin Impregnation

Study on Compression Transfer Molding

1995 ◽  
Vol 29 (16) ◽  
pp. 2180-2191 ◽  
Author(s):  
Wen-Bin Young ◽  
Cheng-Wey Chiu
Keyword(s):  
Low Cost ◽  
Fiber Reinforcement ◽  
Mold Filling ◽  
Thickness Direction ◽  
Molding Process ◽  
Transfer Molding ◽  
Rtm Process ◽  
Resin Impregnation ◽  
Filling Time ◽  
Part Dimension

Resin transfer molding (RTM) finishes the resin impregnation and composite fabrication at the same time. It simplifies the process for composites fabrication and has the advantages of automation, low cost, and versatile design of fiber reinforcement. Therefore, the RTM process is widely used in the architecture, automotive, and aerospace industries. However, in the RTM process, resin must flow through the fiber reinforcement in the planar direction, which, in some cases such as fabrications of large panels, may need a long time for the mold filling. If the part dimension is too large or the fiber permeability is too low, the mold filling process may not be able to complete before the resin gels. Therefore, some modification for the RTM process is necessary in order to reduce the mold filling time. In the compression transfer molding, the mold opens a small gap for the resin to fill in between fiber mats and the mold, and then compresses the fiber reinforcement to be impregnated by the resin in the thickness direction. In this way, since resin is forced into the fiber reinforcements in the thickness direction, the damage of the fibers will be minimized. In addition, the mold filling time will be reduced due to the different flow path of the resin inside the mold. This study explored the possibility of using the compression transfer molding process and also identified the key parameters regarding the process.

Artifacts caused by dehydration and epoxy embedding in TEM

1991 ◽  
Vol 49 ◽  
pp. 338-339
Author(s):  
Hilton H. Mollenhauer
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Volume Change ◽  
Tissue Damage ◽  
Beam Specimen ◽  
Chemical Fixation ◽  
Resin Impregnation ◽  
Storage Vesicles ◽  
A Cell ◽  
Tissue Shrinkage

Various means have been devised to preserve biological specimens for electron microscopy, the most common being chemical fixation followed by dehydration and resin impregnation. It is intuitive, and has been amply demonstrated, that these manipulations lead to aberrations of many tissue elements. This report deals with three parts of this problem: specimen dehydration, epoxy embedding resins, and electron beam-specimen interactions. However, because of limited space, only a few points can be summarized.Dehydration: Tissue damage, or at least some molecular transitions within the tissue, must occur during passage of a cell or tissue to a nonaqueous state. Most obvious, perhaps, is a loss of lipid, both that which is in the form of storage vesicles and that associated with tissue elements, particularly membranes. Loss of water during dehydration may also lead to tissue shrinkage of 5-70% (volume change) depending on the tissue and dehydrating agent.

A MULTISCALE MODEL OF RATE DEPENDENCE OF NANOCRYSTALLINE THIN FILMS

2012 ◽  
Vol 10 (5) ◽  
pp. 441-459 ◽  
Author(s):  
Fernando V. Stump ◽  
Nikhil Karanjgaokar ◽  
Philippe H. Geubelle ◽  
Ioannis Chasiotis
Keyword(s):  
Thin Films ◽  
Multiscale Model ◽  
Rate Dependence ◽  
Nanocrystalline Thin Films

Fiber energy efficiency Part I: Extended entropy model

2014 ◽  
Vol 29 (2) ◽  
pp. 322-331 ◽  
Author(s):  
Anders Karlström ◽  
Karin Eriksson
Keyword(s):  
Energy Efficiency ◽  
Temperature Profile ◽  
Dynamic Models ◽  
Fluid Dynamic ◽  
Multiscale Model ◽  
Process Conditions ◽  
Entropy Model ◽  
Refining Zone ◽  
Energy Balances ◽  
Flat Zone

Abstract This is the first in a series of papers presenting the development of a comprehensive multiscale model with focus on fiber energy efficiency in thermo mechanical pulp processes. The fiber energy efficiency is related to the defibration and fibrillation work obtained when fibers and fiber bundles interact with the refining bars. The fiber energy efficiency differs from the total refining energy efficiency which includes the thermodynamical work as well. Extracting defibration and fibrillation work along the radius in the refining zone gives information valuable for fiber development studies.Models for this process must handle physical variables as well as machine specific parameters at different scales. To span the material and energy balances, spatial measurements from the refining zone must be available. In this paper, measurements of temperature profile and plate gaps from a full-scale CD-refiner are considered as model inputs together with a number of process variables. This enables the distributed consistency in the refining zone as well as the split of the total work between the flat zone and the CD-zone to be derived. As the temperature profile and the plate gap are available in the flat zone and the CD-zone at different process conditions it is also shown that the distributed pulp dynamic viscosity can be obtained. This is normally unknown in refining processes but certainly useful for all fluid dynamic models describing the bar-to-fiber interactions. Finally, it is shown that the inclusion of the machine parameters will be vital to get good estimates of the refining conditions and especially the split between the thermodynamical work and the defibration/fibrillation work.

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