• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.3
• /
• pp.249-257
• /
• 2013

Rapid prototyping was used to design and develop a three-dimensional (3D) scaffold for tissue engineering application. In this study, the nozzle guide (TB-CP-HN, MUSASHI ENGINEERING, INC., JAPAN) used with the syringe of the polymer deposition system (PDS) was evaluated by measuring the scaffold line width and height. 3D scaffolds were fabricated using a biodegradable polymer called poly-caprolactone (PCL). The PCL polymer can be deposited from the needle of a syringe using a 200-${\mu}m$ precision nozzle, at a pressure of 600 kPa and temperature of $125^{\circ}C$. The advantages and improvements in this nozzle guide were addressed through washer scaffold fabrication. Overall, this research indicated that the fabrication of a complex-shaped scaffold using an enhanced polymer deposition system may have potential for tissue engineering.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.3 no.2
• /
• pp.110-114
• /
• 2002

The master pattern manufacturing process is one of the most important processes in jewelry industry because the process takes 20% of total jewelry manufacturing costs. The previous jewelry manufacturing process has many steps of "rough design${\leftrightarro}$ detailed drawing${\leftrightarro}$ wax pattern manufacturing ${\leftrightarro}$ lime soda flask mold manufacturing ${\leftrightarro}$ silver master pattern manufacturing ${\leftrightarro}$ mass production of wax pattern ${\leftrightarro}$ investment casting process ${\leftrightarro}$ final jewelry product." A novel process that reduces processing steps by using a rapid prototyping system (RP) has been suggested. The process is "3D CAD design ${\leftrightarro}$ DuraForm mold manufacturing by RP ${\leftrightarro}$ manufacturing master pattern by low melting alloy ${\leftrightarro}$ mass production of wax pattern ${\leftrightarro}$ investment casting process${\leftrightarro}$ final jewelry product." Molds are made with DuraForm powder, of which melting temperature is 19$0^{\circ}C$, by a selective laster sintering type RP. An alloy of Pb-Sn-Bi-Cd, of which melting temperature is $70^{\circ}C$, is casted in the DuraForm molds. Spheres and rings of diameter 20 mm are made by this process. The dimension deformation rate is less than 2%, and the post processing of the castings is convenient. The casting made by the suggested process can be used as a master pattern of jewelry products.of jewelry products.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.536-539
• /
• 2002

The reverse engineering (RE) technology can quickly generate 3D point cloud data of an object by capturing the surface of a model using a 3D scanner. In the rapid prototyping (RP) technology, prototypes are rapidly produced from 3D CAD models in a layer-by-layer additive basis. In this paper, a physical human head shape is duplicated using a new RP process, the Transfer-type Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-ST), after the point cloud data of a human head shape measured from 3D SNX scanner are converted to STL file. From the duplicated human head shape, it has been shown that the VLM-ST process in connection with the 3D scanner is a fast and efficient process in that shapes with free surface, such as the human head shape, can be duplicated with ease. Considering the measurement time and the shape duplication time, the use of 3D SNX scanner and the VLM-ST process is expected to reduce the lead-time fur the development of new products in comparison with the other existing RE-RP connected manufacturing systems.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.50-53
• /
• 2003

Most companies use technologies such as stereolithography, selective laser sintering, and fused deposition modeling to make parts for such small consumer products as telephones, heads, and shoes. The largest part that the existing RP systems can make is only 600 mm in length. Because most RP systems build parts by depositing, solidifying, or sintering material point-by-point, making larger objects takes a long time. and in many cases, large objects won't fit the build size. A new effective thick-layered RP process. Transfer type Variable Lamination Manufacturing using expandable polystyrene foam (VLM-ST) has been developed with thick layers and sloped surfaces. In this paper, a scaledown model of F16 Fighter with the length of 800 mm is rapidly fabricated using the VLM-ST process. In order to build a CAD model of F16 larger than 600 mm in length, the approach in VLM-ST is to build larger parts in multiple sub-parts and then glue them together. The fabricated result shows that the VLM-ST process employing thick layers and sloped surfaces is adequate for creating the real-sized large objects in the diverse fields such as automobiles, electric home appliances, electronics. and etc.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.9
• /
• pp.839-844
• /
• 2017

In the past few years, three-dimensional (3D) printing has been developed as a rapid prototyping (RP) technique. The fused deposition modeling (FDM)-type 3D printing is one of the most useful RP methods; however, it still has several disadvantages, such as low conductivity, heat degradation, and low surface quality. In this study, test specimens are fabricated using an FDM-type 3D printer with an ABS material. Then, the specimens undergo post-processing on submerging in acetone with various processing times. As the processing time increases, surface roughness is enhanced significantly within the first five seconds by chemical processing, following which the processing effects are reduced. Furthermore, post processing causes the ultimate strength and strain to increase slightly with increased processing time.

• Polymer(Korea)
• /
• v.38 no.1
• /
• pp.93-97
• /
• 2014

Biodegradable drug-eluting stent has dual functions of supporting the lumen and treating internal tumor preventing the restenosis by releasing drug. In this study, the polycaprolactone (PCL) based three dimensional (3D) mesh loaded with paclitaxel (PTX) was presented by rapid prototyping (RP) technique of solid freeform fabrication (SFF) for biodegradable drug-eluting stent application. PCL has many advantageous properties such as good biocompatibility, good mechanical properties, and good drug permeability. PTX is widely used in the cancer treatment by inhibiting tumor cell proliferation. Analytical methods of HPLC and NMR were used for simultaneous quantification of PTX. Scanning electron microscopy (SEM) was performed to observe the architecture and morphologies of 3D mesh. The cytotoxicity assay results indicated released PTX's biological activity. This study provided that PCL based 3D mesh loaded with PTX by RP technique has great potential for biodegradable drug-eluting stent application.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.7
• /
• pp.174-178
• /
• 2001

In order to reduce the lead-time and cost, recently the technology of rapid protoyping and manufacturing(RPM)has been widely used. Machining process is still considered as one of the effective RPM methods that have been developed and currently available in the industry. It also offers practical advantages such as precision and versatility. Some considerations are still required during the machining process. One of the most important points is fixturing. There should be an effective method of fixturing since the fixturing time depends on the complexity of geometry of the part to be machined. In this paper, the rapid manufacturing process has been developed combining machining with automatic filling. The proposed fixturing technique using automatic filling can be widely applicable to free surface type of product such as a fan. In the filling stage, remeltable material is chosen for the filling process. An automatic set-up device attachable to the table of the machine has also been developed. The device ensures the quality during a series of machining operations. This proposed process has shown to be a useful method to manufacture the required products with the reduced the response-time and cost.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.11a
• /
• pp.517-518
• /
• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.58-61
• /
• 2003

제품이 요구하는 기능성 소재(금속, 합금, 세라믹 등)를 사용하여 컴퓨터에 저장되어 있는 3차원 형상의 기하학적 자료(digital data of 3D subjects)로부터 직접 3차원 형상의 제품 또는 제품생산에 필요한 툴(tools)을 매우 빠른 시간 내에 제작할 수 있는 신개념의 쾌속 직접금속성형기술(laser-aided direct metal fabrication tech.)임.(중략)

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.06a
• /
• pp.721-722
• /
• 2007