Article

Low-cost manufacturing and recycling of advanced biocomposites

Taylor & Francis
Journal of Natural Fibers
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Abstract

In this paper, the capabilities of Specialized Elastomeric Tooling for Resin Infusion, a low-cost and low-energy autoclaving alternative for consolidating and curing resin-infused thermoset composite parts, are expanded to biobased composites. Specifically, multiple flat laminate parts (10-ply stack of woven cellulose fiber with a high bio-content, recyclable epoxy resin matrix) are infused with bioresin, consolidated between a temperature-controlled rigid tool and matching rubber-faced tool specially engineered to provide uniform pressure under load, and then thermally cured in place. As expected, parts made using this process are thinner, have higher stiffness and strength, and have fewer surface voids as consolidation pressure is increased. Experimental results reported include resin infusion observations, part thickness, surface roughness, microscopy, tensile strength/modulus, and flexural strength/modulus. Following consolidation and curing, the recyclability of the cellulose textile is assessed by dissolving the commercially available bioresin in a dilute acetic acid bath to create a recyclable thermoplastic.

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Article
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An alternative process to autoclaving, called Thermal Press Curing (TPC), is proposed, whereby an uncured composite laminate is pressed between a heated curing mold and customized rubber-faced mold that are designed to provide uniform temperature and pressure conditions. TPC was demonstrated by designing a complex 3-D ‘benchmark’ part shape, applying a simple computational algorithm to derive the required tool shapes, and fabricating the tooling. A comparative study was performed involving the benchmark part made from four plies of woven carbon/epoxy prepreg material. Identical laminates were pre-formed by double diaphragm forming and then cured and consolidated by autoclaving, Quickstep, and TPC using standard industry practice. Results of the study indicate that the TPC part is of similar quality as compared to those made by autoclaving and Quickstep, but, more importantly, requiring significantly less energy and resource consumption, lower cost (capital and recurring), and less preparation and cycle time.
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Recylable by design: a chemical approach to recyclable epoxy composites
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