Title: Effects of Scrap Size on Mechanical Properties of Recycled Carbon Fiber Reinforced Plastics

Authors: Yoon-Bo. Shim, Gyueun. Cho, Young-Bin Park

DOI: 10.33599/nasampe/c.22.0053

Abstract: As increasing the demand and using of carbon fiber reinforced plastics (CFRPs) in recent years, the necessity of recycling CFRPs has been also increased. To recycle CFRPs, retrieving carbon fibers is mainly used, and for this, pyrolysis and solvolysis are mainly used. These methods, however, consume enormous energy and have even high global warming potential [1]. In this study, mechanical recycling was suggested to recycle end-of-life CFRPs rather than retrieving carbon fibers for more effective recycling.
The material used in this research was carbon fiber/low melting-poly(aryletherketone) (CF/LM-PAEK) which has high thermal properties and its melting temperature is 305℃. Trimmed or end-of-life CFRPs were shredded the scraps were sieved with different mesh sizes of sieves to be normalized their sizes. To find out the effect of sieving process, particle size distribution (PSD) was analyzed by image analysis and statistical analysis. Compression molding was conducted with different weight fraction of different sizes of scraps by using heating press. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) were conducted to compare thermal properties of each step which are raw material (unidirectional tape), scraps and reCFRPs. Cross section of reCFRPs was observed by optical microscope for evaluating impregnation and stacking quality of the composites. To measure mechanical properties, tensile testing, flexural testing, drop weight impact testing were conducted. After that, fracture mechanisms of the reCFRPs were investigated.
Parameters of compression molding process which are pressure, temperature, time and cooling rate was optimized using results of thermal analysis. PSD was used for investigating the effects on mechanical properties because PSD followed Weibull distribution and it is known that PSD can replace fiber length distribution (FLD) of composites [2]. Small size of scraps had also important role of decreasing variation even larger scraps affected to strength. Through cross section observation, small scraps filled empty spaces between large scraps to bond each other, which leads to have higher reliability.
In this study, it was found that scrap size affects to mechanical properties of recycled carbon fiber reinforced plastics.
Reference [1] F. Meng. SAMPE Europe Conference 2018 Southampton
[2] G. A. Vincent. Composites Part B (2019)

References: 1. Meng, F., Pickering, S. J. & McKechnie, J., “An Environmental Comparison of Carbon Fibre Composite Waste End-Of-Life Options”, Proceedings of the SAMPE Europe Conference, Southampton, UK, 2018 2. Yang, Jie. “Reycling of Carbon Fibre Reinforced Epoxy Resin Composites under Various Oxygen Concentration in Nitrogen-Oxygen Atmosphere.”, Journal of Analytical and Applied Pyrolysis 112, (2015): 253-261 http://dx.doi.org/10.1016/j.jaap.2015.01. 3. Pimenta, Soraia. “Recycling Carbon Fibre Reinforced Polymers for Structural Applications: Technology Review and Market Outlook”, Waste Management 31 (2011): 378-392 https://doi:10.1016/j.wasman.2010.09.019 4. Howarth, Jack., “Energy Intensity and Environmental Analysis of Mechanical Recycling of Carbon Fibre Composite”, Journal of Cleaner Production 81 (2014): 46-50 https://doi.org/10.1016/j.jclepro.2014.06.023 5. Pietroluongo, Mario., “Mechanical Recycling of an End-Of-Life Automotive Composite Component”, Sustainable Materials and Technologies 23 (2020) e00143 https://doi.org/10.1016/j.susmat.2019.e00143 6. Vincent, Guillaume, A., “Shredding and Sieving Thermoplastic Composite Scrap: Method Development and Analyses of the Fibre Length Distributions”, Composites Part B 176 (2019): 107197 https://doi.org/10.1016/j.compositesb.2019.107197 7. ASTM Standard E11-20, 2022, “Standard Specification for Woven Wire Test Sieve Cloth and Test Sieves”, ASTM International, West Conshohocken, PA, 2022, DOI: 10.1520/E0011-20, www.astm.org. 8. ASTM Standard D790-17, “Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials”, ASTM International, West Conshohocken, PA, 2017, DOI: 10.1520/D0790-17, www.astm.org. 9. Landry, Benoit., “Experimental Study of Defect Formation during Processing of Randomly-Oriented Strand Carbon/PEEK Composites”, Composites Part A 77 (2015): 301-309 https://doi.org/10.1016/j.compositesa.2015.05.020 10. Gao, Shang-Lin., “Cooling Rate Influences in Carbon Fibre/PEEK Composites. Part 1. Crystallinity and Interface Adhesion”, Composites Part A 31 (2000): 517-530 https://doi.org/10.1016/S1359-835X(00)00009-9

Conference: CAMX 2022

Publication Date: 2022/10/17

SKU: TP22-0000000053

Pages: 8

Price: $16.00