• Proceedings of the KSME Conference
• /
• 2005.11a
• /
• pp.211.2-211.2
• /
• 2005

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.11a
• /
• pp.543-544
• /
• 2007

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.7
• /
• pp.19-26
• /
• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.10a
• /
• pp.15-16
• /
• 2006

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.7
• /
• pp.13-18
• /
• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.193-194
• /
• 2006

A solid freeform fabrication (SFF) system using selective laser sintering (SLS) is currently recognized as a leading process and SLS extends the applications to machinery and automobiles due to the variousmaterials employed. In order to develop a more elaborate and rapid system for fabricating large objects compared to existing SLS, this study employs a new selective dual-laser sintering (SDLS) process. Also, this paper will address development of an SFF system which employs the dual laser system and the unique scanning device. Experiments were performed to evaluate the effect of a scanning path and fabrication parameters on sintering process and to fabricate the various 3D objects using polymer powder.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.7
• /
• pp.7-12
• /
• 2008

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.1389-1393
• /
• 2007

Selective Laser Sintering (SLS) is currently recognized as a leading process in the new field of solid freeform fabrication (SFF). It is used to fabricate in a short time any 3 dimensional shapes by layer-by-layer sintering of polymer, ceramic or metal powder. To develop this SFF system, it needs effective laser scanning path, temperature and z-axis control for lamination. Therefore, in this study, through the application of control algorithm for sintering process have performed, temperature evaluation for sintering process has performed and the manufacturing sample using SLS process.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.32 no.7
• /
• pp.602-609
• /
• 2008

This paper presents experimental optimization of process parameters for a newly developed SFF(Solid Freeform Fabrication) system. Two critical process parameters, layering thickness and curing period, which have a large effect on the quality of the product, are optimized through experiments. Specimens are produced using layering thicknesses of 60, 80, 100, 120, 140, and $160\;{\mu}m$ and curing periods of 0, 10, 20, and 30 minutes under the same processing conditions, i.e., build-room temperature, feed-room temperature, roller speed, laser power, scan speed, and scan spacing. The specimens are tested to compare and analyze performance indices such as thickness accuracy, flatness, stress-strain characteristics, and porosity. The experimental result indicates that layering thickness of $80{\sim}100\;{\mu}m$ and curing period of $20{\sim}30$ minutes are recommended for the developed industrial SFF system.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.1404-1409
• /
• 2007

Polymers for laser sintering were needed in order to fabricate the articles with the three-dimensional duplication equipment of SLS (selective laser sintering) process. The thermal properties, particle size, distribution, and shape of polymer powder had a close relation with the processibility of laser sintering. In this study, we prepared new polymer powders with uniform size and higher bulk density by wet process. Wet process consists of several finely-controlled steps such as dissolution, nucleation, propagation and crystallization. Several additives were added to improve the thermal, rheological, and flow properties.