Direct Ink Writing of Ethyl Cellulose and Its Composites
Open Access
- Author:
- Reinert, Tyler
- Area of Honors:
- Mechanical Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Zoubeida Ounaies, Thesis Supervisor
Margaret Louise Byron, Thesis Honors Advisor
Amrita Basak, Thesis Supervisor - Keywords:
- Ethyl Cellulose
Biopolymer
3D printing
biopolymer printing
additive manufacturing
EC - Abstract:
- This thesis focuses on the Direct Ink Writing (DIW) of Ethyl Cellulose (EC). EC is a natural biopolymer derived from plants with the capability of revolutionizing the sustainable manufacturing of polymers. Nontoxic, food-grade safe, and insoluble in water, EC is not only sustainable but ideal for pharmaceutical and cosmetic industries. 3D printing is an additive manufacturing technique allowing customization and optimization of small-scale designs at lower costs. Additionally, 3D printing reduces by-products and waste during production, yielding a more sustainable process. In this thesis, DIW is the 3D printing method selected for this thesis due to relative ease of use, access to equipment, and prior success with printing paste-like inks. The printer is developed from customizing a common off the shelf printer. To effectively print higher solid content EC-based inks, the print parameters, such as print speed, gap height, and extrusion amount, must be defined, and their impact on the print must be understood. Furthermore, the composition of the EC ink, including with additives, must be optimized to maximize print quality and curing capabilities. Finally, the curing procedure requires investigation to minimize spreading and maximize solvent elimination, which will maintain print geometry. A series of experiments demonstrated that both the gap height and the print speed have minimal impact on the print within a viable range, whereas extrusion dominates the print geometry. As the solid content of the ink increases, the viable print parameter window shrinks, with only low extrusion yielding predictable results. The addition of silica modified the ink properties, allowing the printability of higher solid content inks with more structural integrity, capable of better maintaining print geometry during curing. Curing at different temperatures and different conditions reveals optimum curing conditions, so the print can be rid of solvent while minimizing spreading. This study of print parameters and curing conditions is necessary to enable the 3D printing of EC inks.