A large amount of uncured thermoset prepreg scrap is generated during manufacturing, including both ply cutter trim waste and out-of-spec material. While techniques to recycle end-of-life cured composite waste and reclaim carbon fiber are well established and commercialized, there is little effort made presently towards reusing uncured scrap prepreg. Here, we present a viable and scalable technique to process scrap prepreg into intermediate forms that can be readily manufactured into commercial end-products. Using out-of-autoclave carbon fiber/epoxy prepreg as an example, we report the mechanical properties, microstructure, and performance of composite laminates fabricated with scrap prepreg under various processing conditions. Demonstrator parts manufactured with scrap prepreg are also presented.
PickeringSJ. Recycling technologies for thermoset composite materials—current status. Compos Part A2006; 37: 1206–1215.
4.
PimentaSPinhoST. Recycling carbon fibre reinforced polymers for structural applications: technology review and market outlook. Waste Manage2011; 31: 378–392.
5.
GoodshipV. Management, recycling and reuse of waste composites, Boca Raton, FL: CRC Press, 2010.
6.
WitikRATeuscherRMichaudVet al.Carbon fibre reinforced composite waste: an environmental assessment of recycling, energy recovery and landfilling. Compos Part A2013; 49: 89–99.
7.
AsmatuluETwomeyJOvercashM. Recycling of fiber-reinforced composites and direct structural composite recycling concept. J Compos Mater2014; 48: 593–608.
8.
WardCPotterKIn-process composite recycling in the aerospace industry. In: GoodshipV (ed). Management, recycling and reuse of waste composites, Boca Raton, FL: CRC Press, 2010, pp. 458–494.
9.
UnserJF. Reuse of scrap prepreg. 42nd International SAMPE Symposium▪▪. Anaheim, CA, USA, 4–8 May 1997.
10.
Imparato SI, Pace G, Capasso L, et al. Method for recycling scraps of prepreg materials. Report No. US 8298359, 30 October 2012.
11.
US Department of Defense. Composite materials handbook, Volume 3: Polymer matrix composites: Materials usage, design, and analysis, MIL-HDBK-17-3F, Washington, DC: Author, 2002.
12.
Unser JF. Advanced composites recycling/reuse program. Final Report, WL-TR-95-7014, April 1995. FL, USA: Wright Laboratory, Armament Directorate, Eglin AFB.
13.
Composite prepreg scrap reclamation program, McDonnell Douglas Corporation, MDC 95P0078. Final Report, Contract Number N00014-90-CA-0002 for Great Lakes Composites Consortium, 1995.
14.
Allred RE. Recycling process for scrap composites and prepregs. In: 41st International SAMPE Symposium, Anaheim, CA, 24–28 March 1996, pp.21–31.
15.
Michaeli W and Oelgarth A. New technologies for processing of non-cured prepreg waste – preparation of high-strength DMC. In: 41st International SAMPE Symposium, Anaheim, CA, 24–28 March 1996, pp.1551–1562. Available at: www.sampe.org.
16.
Evans AJS. A moulding compound and a method of manufacturing the compound. Patent WO1989009123A1, 1989.
17.
Ward C and Potter K. Understanding composites design and manufacturing for minimization of scrap generation: the first steps to efficient material use. In: SAMPE Europe International Conference (SEICO), Paris, France, 31 March–2 April 2008.
18.
Ward C and Potter K. A methodology for the reuse of uncured prepreg scrap. In: SAMPE Europe International Conference (SEICO), Paris, France, 23–25 March 2009, pp.153–158.
19.
Miracle DB and Donaldson S. ASM Handbook Volume 21: Composites. ASM International, ISBN: 978-0-87170-703-1.
20.
Fudge JD. Chopped prepregs – a compelling performance and cost alternative material form. In: SAMPE Fall Technical Conference, Wichita, KS, 19–22 October 2009.
21.
Nilakantan G and Nutt S. A peek into the future “Salvaging the Scrap Heap.” Composites Manufacturing Magazine. September–October 2015, pp. 21–23.
22.
NilakantanGNuttS. Reuse and upcycling of aerospace prepreg scrap and waste. Reinforc Plast2015; 59: 44–51.
23.
Nilakantan G, Olliges R, Su R, et al. Reuse strategies for carbon fiber-epoxy prepreg scrap. In: CAMX Conference, Orlando, FL, 13–16 October 2014.
24.
CYCOM 5320 Toughened Epoxy for Structural Applications, Out-of-Autoclave Manufacturing, Cytec Data Sheet.
25.
Lucas S, Howard S and Senger J. Vacuum bag only processing: improving prepreg out-time and porosity for large composite structure. In: SAMPE Conference, Seattle, WA, 2010. Available at: www.cytec.com.
26.
CenteaTGrunenfelderLKNuttSR. A review of out-of-autoclave prepregs – material properties, process phenomena, and manufacturing conditions. Compos Part A2015; 70: 132–154.
