Research Team from Oak Ridge National Lab and the UMaine Composites Center receive award for innovation in green composites design

Researchers from Oak Ridge National Laboratory (ORNL) and the University of Maine received a prestigious Award for Composites Excellence for research conducted in 3D printing a sustainable biocomposite foam for use in lightweight structural applications. The award, presented to the ORNL and UMaine team by the American Composites Manufacturers Association, recognizes outstanding achievement in innovation in green composites design.

The ORNL and UMaine team is leading research on new forest-derived bio-based materials to replace fossil-based feedstocks in 3D printing applications. These low-cost materials combine nanocellulose with recyclable resins to create a more environmentally friendly material that can be produced locally. With the rapid growth of 3D printing or additive manufacturing in industrial applications, these forest-derived feedstocks are a promising new market for Maine’s forest products industry.

The ORNL and UMaine team received the award during CAMX, the largest composites and advanced materials event in North America.

Additive manufacturing of lightweight structures: 

Microfibrillated cellulose – PLA biofoams

Halil L. Tekinalp, Stefan Dopatka, Tyler Smith, William Peter, Soydan Ozcan

Manufacturing Demonstration Facility, Oak Ridge National Laboratory

 James Anderson, Douglas J. Gardner, Yousoo Han

Advanced Structures and Composites Center, University of Maine

ABSTRACT

Extrusion-based polymer additive manufacturing (AM) technology is growing rapidly. The introduction of fiber reinforced feedstock materials and recent developments in the manufacturing systems have promulgated large scale AM of composites to create new industries and applications. Synthetic fibers such as carbon and glass fibers are commonly used to reinforce polymer composites. However, increasing environmental and long-term sustainability concerns are leading to new materials using cellulose fiber reinforcement in bio-derived polymers. These materials offer new property sets, new supply chains and have the potential to provide economical solutions leading to new applications. Large scale AM can be attractive for many different applications because of its ability to freeform manufacture complex geometries; each application may require different material properties. One of the novel application areas for large scale AM is 3D printing of lightweight materials via foaming. Although achieving low density is the key in light weighting via foaming, mechanical performance is also important for many applications. In this study the impact of micro-cellulose fibers (MFC) on foaming behavior and the mechanical properties of additively manufactured parts is investigated. MFC-polylactic acid (PLA) feedstock pellets were prepared at varying MFC content (5, 10, 15 and 20 wt.%) to understand the impact of cellulose fiber content on density and mechanical properties of the AM biocomposites. Also, the impact of extrusion speed and foaming agent content on the AM biocomposites is investigated. Although achieving uniform printed foam structure is challenging with the presence of cellulose fibers, promising results were accomplished with density values below 0.5g/cm3.