Molten Salt Assisted Pyrolysis Recycling of Glass Fiber Reinforced Polymer Composites

The Problem:​

Glass fiber reinforced composites (GFRPs) make up approximately 90% of all produced fiber-reinforced composite materials. Disposal of end-of-life composite parts and composite manufacturing waste has become more difficult with expanding landfill regulations, and recycling of glass fibers in is particularly challenging since state-of-the-art recycling methods result in a significant drop in both performance (i.e. tensile strength) and processability.​

The Solution:​

Dr. Ginder has developed a molten-salt assisted pyrolysis recycling method for GFRPs which yields a pristine glass fiber surface by removing carbonaceous char and other inorganic materials while employing a chemically strengthening molten potassium nitrate solution to recover more of the tensile strength and properties of virgin fibers. This method avoids the strength-damaging effects of traditional char removal processes. ​

Figure 1: 

 

Comparison of tensile strength loss from recycling in traditional oxygen burn off approach versus molten salt pyrolysis.​

Benefits: 

• Avoids major losses in tensile strength associated with traditional char removal recycling processes. ​

• Allows for addition of sizing agents to further increase tensile strength and processability. ​

• Bath solution results in pristine recycled fiber surfaces, free from carbonaceous char and residual inorganic materials.​

Inventor:

 

Ryan Ginder

Research Assistant Professor, Department of Aerospace, Mechanical, and Biomedical Engineering

Dr. Ginder received his PhD in Materials Science and Engineering from the University of Tennessee, Knoxville, in 2016. His research interests include mechanics of materials, composites and functional materials, materials for energy applications, and materials recycling and sustainability.

Dr. Ginder has journal articles in publications such as Advanced Materials, Scripta Materialia, Journal of the Mechanics and Physics of Solids, Journal of Materials Research, and more. Dr. Ginder also worked in the Carbon and Composites Group at Oak Ridge National Laboratory.

Patent Information: