Assessment of flow and cure monitoring using direct current and alternating current sensing in vacuum-assisted resin transfer molding

2000 ◽  
Vol 9 (6) ◽  
pp. 727-736 ◽  
Author(s):  
Uday K Vaidya ◽  
Nitesh C Jadhav ◽  
Mahesh V Hosur ◽  
John W Gillespie ◽  
Bruce K Fink
Keyword(s):  
Direct Current ◽  
Resin Transfer Molding ◽  
Alternating Current ◽  
Current Sensing ◽  
Transfer Molding ◽  
Cure Monitoring

Assessment of Flow and Cure Monitoring Using Direct Current and Alternating Current Sensing in Vacuum Assisted Resin Transfer Molding

1999 ◽  
Author(s):  
Nitesh C. Jadhav ◽  
Uday K. Vaidya ◽  
Mahesh V. Hosur ◽  
John W. Gillespie ◽  
Bruce K. Fink
Keyword(s):  
Direct Current ◽  
Large Scale ◽  
Resin Transfer Molding ◽  
Alternating Current ◽  
Composite Panel ◽  
Current Sensing ◽  
Transfer Molding ◽  
Cure Monitoring ◽  
The Matrix ◽  
Automated Fiber Placement

Abstract Vacuum Assisted Resin Transfer Molding (VARTM) is an emerging manufacturing technique that holds promise as an affordable alternative to traditional autoclave molding and automated fiber placement for producing large scale structural parts. In VARTM, the fibrous preform is laid on a single sided tool, which is then bagged along with the infusion and vacuum lines. The resin is then infused through the preform, which causes simultaneous wetting in its in-plane and transverse directions. An effective sensing technique is essential so that comprehensive information pertaining to the wetting of the preform, arrival of resin at various locations, cure gradients associated with thickness and presence of dry spots may be monitored. In the current work, direct current and alternating current sensing/monitoring techniques were adopted for developing a systematic understanding of resin position and cure on plain weave S2-Glass preforms with Dow Derakane vinyl ester VE 411-350, Shell EPON RSL 2704/2705 and Si-AN epoxy as the matrix systems. The SMARTweave DC sensing system was utilized to conduct parametric studies a) to compare the flow and cure of resin through the stitched and non-stitched preforms, b) influence of sensor positioning, i.e., top, middle and bottom layers, c) influence of positioning of the process accessories, i.e., resin infusion point and vacuum point on the composite panel. The SMARTweave system was found to be sensitive to all the parametric variations introduced in the study. Furthermore, the results obtained from the SMARTweave system were compared to the cure monitored from embedded IDEX dielectric sensors. The results indicate that SMARTweave sensing was a viable alternative to obtaining resin position and cure, and more superior in terms of obtaining global information in contrast to the localized dielectric sensing approach.

scholarly journals Applicability of fiber Bragg grating sensors for cure monitoring in resin transfer molding processes

2020 ◽  
pp. 073168442095811
Author(s):  
Yannick Blößl ◽  
Gergely Hegedüs ◽  
Gábor Szebényi ◽  
Tamás Tábi ◽  
Ralf Schledjewski ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Resin Transfer Molding ◽  
Sol Gel ◽  
Bragg Grating ◽  
Gel Point ◽  
Strain Response ◽  
Resin System ◽  
Transfer Molding ◽  
Cure Monitoring ◽  
Fiber Bragg Grating Sensors

This article examines the use of fiber Bragg grating sensors for cure monitoring purposes in resin transfer molding processes. Within a resin transfer molding test series a thermoset epoxy-amine resin system was used in combination with a woven flax fiber reinforcement. Particular attention was paid on the location of the optical fiber sensor and its sensitive Bragg grating element inside the mold cavity. Three different installation approaches were tested and the correlation of the corresponding strain response with the actual cure state of the resin system was investigated at 50°C and 70°C isothermal cure temperature, respectively. We could demonstrate that characteristic, conspicuous strain changes are directly related to the sol–gel conversion of the thermoset polymer, which was analyzed considering different approaches for the gel-point detection based on rheological measurements. With the installation of the sensor inside a controllable, capsuled resin volume, we could achieve the most reliable strain response that provides capabilities to give in-situ information of the cure state beyond the gelation point.

Graphene nanocomposites: A review on processes, properties, and applications

2021 ◽  
pp. 152808372110242
Author(s):  
Kadir Bilisik ◽  
Mahmuda Akter
Keyword(s):  
Textile Industry ◽  
In Situ Polymerization ◽  
Resin Transfer Molding ◽  
Single Layer ◽  
Chemical Vapor ◽  
Synthesis Process ◽  
Graphene Nanocomposites ◽  
Transfer Molding ◽  
Potential Applications ◽  
Nano Graphene

In this paper, graphene, graphene/matrix, and graphene/fiber nanocomposites, including their synthesis process, fabrication, properties, and potential applications, were reviewed. It was found that several synthesis techniques for nanographene were developed, such as liquid-phase exfoliation and chemical vapor deposition. In addition, some fabrication processes of graphene/matrix and graphene/fiber-based nanocomposites were made, including in-situ polymerization, nanostitching in that single layer nano graphene plate could be interconnected by means of carbon nanotube stitching, resin transfer molding, and vacuum-assisted resin transfer molding. Several properties, including mechanical, thermal, and electrical, on the graphene nanoplatelets materials were summarized in this review paper. It was realized that graphene, graphene/matrix, and graphene/fiber nanocomposites have extraordinary mechanical, thermal, and electrical properties used in advanced engineering applications, including soft robotics, microelectronics, energy storage, biomedical and biosensors as well as textile industry.

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.

Optimization of Resin Infusion Processing for Composite Pipe Key-Part and K/T Type Joints Using Vacuum-Assisted Resin Transfer Molding

2016 ◽  
Vol 23 (5) ◽  
pp. 1065-1078 ◽  
Author(s):  
Changchun Wang ◽  
Guanghui Bai ◽  
Guangquan Yue ◽  
Zhuxi Wang ◽  
Jin Li ◽  
...  
Keyword(s):  
Resin Transfer Molding ◽  
Resin Infusion ◽  
Transfer Molding ◽  
Composite Pipe
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