Review of recycling methods of thermoplastic composite materials

ABSTRACT

Usage of thermoplastic composites with low densities is increasing, with lightness coming to the fore especially in the aerospace industry while various sectors like automotive, electronics, sport etc. are also following the trend. Important factors for the preference of thermoplastics are the increase in the amount of waste of conventional materials in addition with increasing product requirements. Composite wastes are accumulated in certain composite collection centers in the world and disposed by incineration. Until at least 2025, studies on recycling are carried out in the European Union. Within this regard, the most important feature of thermoplastics is that they can be melted and shaped again at high temperatures. In this way, recycling of fibers and matrices is possible. Mainly thermal and chemical methods are preferred for obtaining fibers while mechanical methods are preferred for obtaining the matrix. Hence, it is aimed to use both open and closed loop recycling in order to reduce wastes, energy consumption, fossil fuel consumption, and the carbon footprint. Note that these recycling approaches are also of significance for the circular economy concept. Correspondingly, this review thematizes current recycling methods for thermoplastic composites.

GRAPHICAL ABSTRACT

KEYWORDS:

• Aerospace applications
• circular economy
• composite recycling method
• environmental impact
• mechanical methods
• recycling
• thermoplastic composite recycling

Acknowledgments

Authors acknowledge Turkish Aerospace due to its support and encouragement. Authors also thank Bengü Yıldız Zeyrek for her support.

Data availability statement

Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Yasemin Sümeyye Türker

Yasemin Sümeyye Türker Yıldırımoğlu received her Bachelor’s degree in Mechanical Engineering from Ankara Yıldırım Beyazıt University in 2019. She then pursued her Master’s degree in Mechanical Engineering and completed it in 2022. Since 2019, she ‘s work’ng as a Composite Process Engineer at Turkish Aerospace. Yasemin’s professional experience has enriched her research endeavors, focusing on manufacturing of thermoset/thermoplastic materials while her research interests encompass recycling of thermoplastic materials.

Fahrettin Özturk

Prof. Dr. Fahrettin Öztürk currently works as Chairman of the Board at TUSAS Engine Industries (TEI), Executive Vice President at Turkish Aerospace and as a faculty member in the Department of Mechanical Engineering at Ankara Yıldırım Beyazıt University. Prof. Özturk received all his degrees from the Department of Mechanical Engineering and graduated from Selçuk University in 1992. He then received his M.Sc. from the University of Pittsburgh, USA in 1996 and his Ph.D. from Rensselaer Polytechnic Institute, USA in 2002. During his time in the USA, he worked at the General Electric Research Center for 3 years.He has more than 30 years of experience in academia, industry and management.Prior to Turkish Aerospace, Prof. Fahrettin Ozturk worked at Rensselaer Polytechnic Institute, Niğde Ömer Halisdemir University (formerly Niğde University) and Khalifa University (formerly The Petroleum Institute (PI)), respectively. Dr. Özturk’s main areas of expertise are; sheet metal forming, material processing and characterization, lightweight materials, thermoplastic composite materials, additive manufacturing, friction stir welding, and mechanically sleeved CRA pipes. He has published 3 books, 6 patents, numerous journal articles, book chapters, conference proceedings, and also writes columns on various topics to contribute to the awareness of the society.

Yahya Öz

Assoc. Prof. Dr. Yahya Öz is the Chief Engineer of the Advanced Composite Materials Technology Center of the R&D and Technology Directorate at Turkish Aerospace, a researcher at the Institute ofMaterials Science and Nanotechnology at Bilkent University and a Visiting Assoc. Prof. Dr. in the Department of Engineering Sciences at the Middle East TechnicalUniversity, Ankara, Turkey. He received his B.Sc. (2011) in Applied Physics and Chemistry, his M.Sc. (2013) and his Ph.D. (2017) in Physics in the Faculty of Mathematics and Natural Sciences at the University of Wuppertal, Germany, where he constructed and solved the Hubbard model with impurity at arbitrary temperature as well as manipulated the host’s density of states by keeping integrability. Following his Ph.D., he became a postdoctoral researcher and worked on transport properties of integrable systems as well as the hydrodynamic approach for integrable systems out of equilibrium. In 2019, he joined Turkish Aerospace. In 2023, he became an Assoc. Prof. Dr. His current research interests include integrable models, modeling of nanomaterials as well as nanocomposites properties and modeling, fabrication and experimentation of composite materials for aerospace applications. Assoc. Prof. Dr. Yahya Öz is the recipient of the full scholarship (2010-2017) by Germany’s largest, oldest and most prestigious scholarship foundation, the German Academic Scholarship Foundation. He published numerous articles and patents.