Session: 03-20-03: Manufacturing: General

Paper Number: 145575

145575 - Comparison of Vibrational Impacts on Tensile Strength in 3d Printing Materials 

3D printing, a cost-effective option compared to other manufacturing methods, has evolved into a mature technology with widespread industrial applications. The predominant method that 3D printers use, fused deposition modeling (FDM), involves melting thermoplastic which is deposited layer by layer to achieve the predetermined shape. Polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate glycol (PETG), and thermoplastic polyurethane (TPU) are some common materials used in printing. These materials have good mechanical and thermal characteristics that allow them to produce high-quality specimens; however, they often lack significant tensile strength, which limits their overall strength and efficiency. Traditional methods to increase tensile strength involve increasing the infill within the object or increasing the thickness, which may result in longer printing times and higher costs. In-depth research indicates that reducing the thickness between the layers and raster width can improve the tensile strength of the printed material. Additionally, 3D printing is highly susceptible to external vibrations, which may result in prints with undesired wavy patterns known as "ringing," leading to printing errors. Conversely, a 2018 study showed that applying high-amplitude vibrations to the printing nozzle can impact the tensile strength of the 3D printed object by reducing porosity, thereby increasing the overall tensile strength due to the reduction of pores in the object. This research aims to investigate the impact of the ejecting nozzle’s vibration on porosity and tensile strength of various printing materials including PLA, ABS, and PETG. Furthermore, research efforts also aim to visualize layer-by-layer images of the deposited printed material with and without vibration.

 

To conduct the research, both a Tronxy X5SA 3D printer and a vibrating mechanism were utilized. Specifically, an Ocity Vibration Rumble Motor (model B07FL7HQ7Y) was mounted onto the printing stage using a special 3D-printed holder to induce vibrations into the nozzle while printing. The motor was run at voltages of 8-15V, running at approximately 4000-6000 revolutions per minute, generating frequencies between 8-15Hz. Dog-bones in this experiment were printed according to the ASTM Type 1 standards paired with infill levels of 20%, 40%, 60%, and 100%. Different specimens were printed with and without vibrations, varying in infill level and thickness to evaluate the impact of vibration on dog-bone samples. To precisely ascertain the porosity of each specimen, the Archimedes method was adopted: submerging the specimens in water, measuring the displaced liquid volume, as well as the weight of both the dry and wet specimens. The collected porosity data showed an average decrease of 2.9% for the PLA samples and an average decrease of 6.8% for the ABS samples induced with vibration compared to the control dog-bone. To measure the tensile strength of each dog-bone, an INSTRON 5KN machine was used at SJSU, revealing an increase of 7.71% for PLA, an 8.72% increase for ABS, and a 9.2% increase for PETG. These measurements were averaged over a range of fill factors between 20% to 100% with induced vibrations of about 12 Hz. In addition, to enhance the understanding of vibrational impact on the ejecting material distribution, layer-by-layer imaging during printing of dog-bone samples was conducted. The spread of nozzle ejecting material with and without induced vibrations was compared by developing a MATLAB-based imaging process technique. Imaging results showed that a vibrating nozzle was able to fill the open gaps between the printing layers, thereby reducing porosity and increasing the tensile strength of the test samples. This research opens broader avenues for further investigation into experimental techniques of applying low-frequency vibrations on 3D printing, making them suitable for multiple engineering applications.

Presenting Author: Sohail Zaidi San Jose State University

Presenting Author Biography: The author is currently working as a lecturer in the department of mechanical engineering, San Jose State University and is also serving IntelliScience Training Institute as a principle research scientist. Prior to these position, author was affiliated to Agilent Technologies from 2012 to 2015 and to Princeton University from 1999 to 2012. Current research is related to 3D and 4D printing, renewable energy, thermal management, and Plasma medicine.

Authors:

Sohail Zaidi San Jose State University
Vimal Viswanathan San Jose State University
Kc Santosh San Jose State University
Shreyas Ravada IntelliScience Training Institute
Ayati Vyas IntelliScience Training Institute