Today's KNOWLEDGE Share : Researchers Develop Method to Recycle Carbon-fiber Reinforced Polymers

 Today's KNOWLEDGE Share

A team of researchers from Waseda University, led by professor Chiharu Tokoro from the Department of Creative Science and Engineering, have come up with a novel direct discharge electrical pulse method for efficiently recycling CFRPs.

Direct Discharge Electrical Pulse Enhances Carbon Fiber Recycling:

Carbon fiber-reinforced polymers (CFRPs) are used in the aerospace, automotive, and sports equipment industries. However, their recycling remains a major problem. In a recent study, researchers demonstrated a novel direct discharge electrical pulse method for the efficient, effective, and environmentally friendly separation of CFRPs to recover high-quality carbon fibers.

Recycling CFRPs presents a significant challenge, with waste management being a pressing issue. Conventional recycling methods require high temperature heating or chemical treatments, which result in high environmental impact and elevated costs. It has been a challenge to recover high-quality carbon fibers. In this regard, electrohydraulic fragmentation has been proposed as a promising option. In this technique, intensive shockwave impulses generated by high-voltage discharge plasmas are applied along the interfaces of different materials to separate the various components.

Preserves Longer, Higher Strength CFRP Fibers with No Residual Resin

Tokoro stated “In our previous studies, we had already established research expertise in generating shock waves in water using electrical pulse phenomena to efficiently fragment difficult-to-process materials. In applications such as lithium-ion batteries, we discovered that direct discharge, which utilizes Joule heating and vapor expansion of the material itself, is more effective for high-efficiency separation than relying on shock waves.

The direct discharge electrical pulse technique leverages Joule heat generation, thermal stress generation & expansion force due to plasma generation, foregoing the need for heating or chemicals. Researchers compared this method with electrohydraulic fragmentation by examining the corresponding physical properties of recovered carbon fibers, length, tensile strength, resin adhesion, & structural degradation, as well as energy efficiency in terms of fiber separation.

They found that their new technique is more effective for carbon fiber recovery. It preserves relatively longer fibers with higher strength and precisely separates CFRPs into individual fibers without retaining any residual resin on the surface.

Improves Energy Efficiency by At Least 10 Times:

Furthermore, the direct discharge approach improves energy efficiency by a factor of at least 10 compared to traditional alternatives, while reducing environmental impact and promoting resource utilization.

Source: Waseda University/ polymer-additives.specialchem.com