Integration Of Ultrasonic And Vacuum System In Additive Manufacturing To Reduce Staircase Effect Of Printed Parts

• Main Author: Mohamed, Ahmad Syafiq
• Format: Thesis
• Language: English; English
• Published: 2020
• Subjects: T Technology (General); TS Manufactures
• Online Access: http://eprints.utem.edu.my/id/eprint/25428/1/Integration%20Of%20Ultrasonic%20And%20Vacuum%20System%20In%20Additive%20Manufacturing%20To%20Reduce%20Staircase%20Effect%20Of%20Printed%20Parts.pdf; http://eprints.utem.edu.my/id/eprint/25428/2/Integration%20Of%20Ultrasonic%20And%20Vacuum%20System%20In%20Additive%20Manufacturing%20To%20Reduce%20Staircase%20Effect%20Of%20Printed%20Parts.pdf; http://eprints.utem.edu.my/id/eprint/25428/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=119728
• Institution: Universiti Teknikal Malaysia Melaka

Additive Manufacturing (AM) has come a long way since the days of rapid prototyping began with the capability to produce a complex solid part rapidly. AM has begun to be acknowledged and accepted in numerous industries such as aerospace, automotive, medical, and even art. Fused deposition modeling (FDM), one of the AM technologies, is a popular and most used technology based on polymer extrusion method. FDM generally works by depositing a molten thin polymer filament from the nozzle onto the build platform repeatedly layer by layer up to create a solid part. Despite having the advantages to produce part without any complexity restrictions, the known poor surface roughness foraesthetic and functional part produced is the limitation. Literature has found out that one of the main reasons related to thermal aspects, resulting from layer by layer manufacturing nature called as the “stair-stepping” effect. The layer by layer bonding occurred too fast and was not fully solidified together, causing semi-molten layered thermoplastic surface often uneven which cause rough and poor surface finish. It was found that ultrasonic and vacuum technology could improve the layer bonding by ultrasonic energy absorption and reducing the convective heat transfer. The ultrasonic energy absorption by the semi-moltenthermoplastic molecule will cause it to vibrate energetically and cause a rapid rise in temperature and delayed the rapid cooling rate. In a vacuum environment, the reduced amount of air molecules hindered the heat energy to be released from the deposited filament. The surface roughness test conducted from pilot test confirmed that the differentvalue of ultrasonic frequency and level of vacuum pressure does affect the surface roughness of the printed specimens. Then, a total 18 experiments runs generated by using DOE with 54 printed specimens were conducted with two parameters namely ultrasonic frequency and vacuum pressure. The surface roughness quality evaluated through the portable surface roughness tester and optical microscope. Result has found out that the highest percentage improvement (32.77 %) 12.92µm produce by 0kHz/-21inHg. It was found out that under optical microscope, the specimens produced under ultrasonic vibration and vacuum pressure had a better surface roughness compared to normal atmospheric ones. Lastly, the RSM and ANOVA method had validated the significance of the set parameters and the optimised process parameter was 49.56 kHz/-21 inHG for optimal solution of 9.46µm. The ultrasonic and vacuum system integrated FDM was proven to be feasible and this study had increased the understanding of ultrasonic and vacuum technology and FDM to improve the surface roughness of the printed part. Further improvements of ultrasonic and vacuum integrated FDM will allow the creation of improved surface finish quality of complex parts in a wide range of applications.