FFF 3D Printing at University of Tennessee: Enhancing Macroscopic Properties with Nanoscopic Additives
Dayton Phillip Street recently presented his doctoral dissertation, ‘Enhancing the Macroscopic Properties of Parts Printed via Fused Filament Fabrication by Incorporating Nanoscopic Additives,’ at the University of Tennessee. With a focus on creating additives for fused filament fabrication (FFF), Street strives to improve the ‘inferior performance’ of 3D printed polymeric materials.
Polymers are widely used today in many manufacturing applications, and commonly within the 3D printing and additive manufacturing realm. Challenges abound though, which is why the use of additives has becomes so prevalent, along with composites that feature materials like TPU and PLA, carbon fiber and epoxy, antioxidants, and many more.
Many FFF 3D printed parts are prone to issues related to adhesion, cavities, or beads. While these types of problems are common within FFF printing, Street believes that with polymer nanocomposites and ‘active’ additives, mechanical properties can be improved significantly.
Part of the problem in using polymers for FFF 3D printing is that they are already limited in terms of performance—leaving many researchers to delve further into the study of composites. There has been a focus on nanocomposites specifically. These materials are comprised of inorganic additives that possess at least one dimension on the nanoscale, according to Street.
Polymer nanocomposites display excellent mechanical properties in comparison to original polymers without additives.
“By blending the properties of hard and soft matter, polymer nanocomposites allow one to retain the processability associated with polymers while improving the material performance,” explains Street. “However, it is well-known that the material properties of polymer nanocomposites depend significantly on interfacial interactions between the inorganic additive and polymer matrix.”
At least five samples were created for each measurement type on a LulzBot Mini 3D printer:
“Each sample was printed in the X-Y plane at 230 °C with a +45/−45 raster angle. The bed temperature was set to 110 °C. In a typical print, the printer settings were as follows: 0.5 mm nozzle size, 0.425 mm initial layer thickness, 0.25 mm layer height with a 100% fill density, and all other settings were left at standard values set by the Cura software for ABS,” explained Street.
“After each print and in order to minimize sample deformation, the bed was allowed to cool to room temperature prior to removing the sample.”
In evaluating how nanoscopic additives would affect macroscopic properties of parts fabricated via FFF printing, Street performed rheological assessments, tensile testing, and dynamic mechanical analysis (DMA). By measuring the response of a material after DMA applies force, Street was able to determine ‘myriad thermomechanical properties.’ In studying the rheology (involving deformation and flow), Street was better able to understand polymer melt characteristics and effects on performance.
“Macroscopic assessments coupled with rheology measurements suggest that these interconnected sheet-like nanostructures effectively dissipate stress throughout the nanocomposite through graft chain interactions with matrix chains and graft chains on neighboring particles. Additionally, the mechanical performance of FFF-printed parts described in this work surpass those obtained when bare Si NPs were used, which further highlights how manipulating interfacial interactions in polymer nanocomposites, conveyed here by grafted polymer chains, controls organization on the nanoscale and affects the performance of polymer nanocomposites,” concludes Street.
“Results from this research show that the properties of parts printed from these multicomponent blends depend on the self-dimerization strength of the hydrogen bonding groups and the number density of non-bonded interactions. This work is impactful because it demonstrates how the strength and number density of non-bonded, physical interactions can tuned to effectively manage the properties of FFF-printed materials at use and production temperatures.”
What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.[Source / Images: ‘Enhancing the Macroscopic Properties of Parts Printed via Fused Filament Fabrication by Incorporating Nanoscopic Additives’]
Subscribe to Our Email Newsletter
Stay up-to-date on all the latest news from the 3D printing industry and receive information and offers from third party vendors.
You May Also Like
CELLINK Bioprinter Enables Bioprinted Hair Follicles for Skin Regeneration and More
In a landmark achievement, researchers at Rensselaer Polytechnic Institute in New York have successfully 3D-printed hair follicles in lab-grown human skin tissue, marking a significant advancement in the field of...
BICO’s Revival: A Fresh Era with Maria Forss at the Helm
Swedish biotech company BICO (STO: BICO) has been making waves in the industry recently. Ever since Maria Forss assumed the role of CEO in November 2023, the company seems to...
3D Printing Webinar and Event Roundup: November 26, 2023
Things are getting busy again in terms of 3D printing webinars and events! This week is the RSNA annual meeting, the World Manufacturing Forum, and more. HP is holding an...
3D Printing Webinar and Event Roundup: November 5, 2023
Happy Formnext week! But don’t worry, if you can’t make it to Germany this week, there are still several other in-person and online webinar and event options in the industry....
Upload your 3D Models and get them printed quickly and efficiently.