Investigation of unsaturated flow in woven, braided and stitched fiber mats during mold-filling in resin transfer molding

2001 ◽  
Vol 22 (4) ◽  
pp. 491-505 ◽  
Author(s):  
J. Slade ◽  
K. M. Pillai ◽  
S. G. Advani
Keyword(s):  
Unsaturated Flow ◽  
Resin Transfer Molding ◽  
Mold Filling ◽  
Fiber Mats ◽  
Transfer Molding

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.

The effect of different variables on in-plane radial permeability of natural fiber mats

2016 ◽  
Vol 37 (19) ◽  
pp. 1191-1201 ◽  
Author(s):  
Michael Ehresmann ◽  
Ali Amiri ◽  
Chad Ulven
Keyword(s):  
Fiber Volume Fraction ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Resin Transfer Molding ◽  
Limited Information ◽  
Fiber Volume ◽  
Fiber Mats ◽  
Transfer Molding ◽  
Fiber Size ◽  
Wax Content

There has been a vast growth in manufacturing of fiber reinforced plastics by means of liquid composite molding such as resin transfer molding and vacuum-assisted resin transfer molding processes. In these processes, compression of the porous media and pressure of the injected resin result in in-mold forces that need to be determined. Limited information exists regarding the processing parameters and extent of reinforcing potential natural fibers have in polymer matrices. Current study investigates the effect of different variables such as fiber volume fraction, shive content, fiber size, wax content, and resin viscosity on permeability of five different natural fiber mats. Flax fiber with low-, medium-, and high-shive content as well as hemp and kenaf fiber mats was selected for this study and an original experimental device was setup to measure the permeability of the mentioned fiber mats based on different variables. It was found that increasing fiber volume fraction will result in reduction of permeability of all mats. The presence of shive and larger fiber size increased the permeability. Higher wax content lowered the permeability. These competing factors could be used by manufacturers to produce a mat which had optimum permeability while still maintaining acceptable strength.

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.

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