• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.187-195
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• 2006

FDM, SLS, and EOS processes are the layered manufacturing processes far functional prototypes. In this paper, bench mark tests of those processes were carried out using various materials. The test includes mechanical properties, such as tensile and compressive strengths, hardness, impact strength, and heat resistance, and surface roughness, shape and dimensional accuracy, manufacturing time, and manufacturing costs. It is verified that SLS method is advantageous in surface roughness and manufacturing time, EOS method in shape accuracy, and FDM method is great in manufacturing costs.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.11
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• pp.126-133
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• 2008

Rapid Prototyping (RP) has been widely used for rapid development of prototypes in various industrial fields. In recent years, a new requirement in RP industry has issued so as to directly manufacture a functional prototype which has enough mechanical properties to be used as a functional part. The RP prototype, however, has a limitation in mechanical properties due to its layer-by-layer manufacturing process. This manufacturing process results in anisotropy of the prototype, especially showing weakness in the building direction. In the present work, we performed tensile tests for RP prototypes in order to determine directional mechanical properties. The test specimens were made by using $Eden330^{TM}$ by Object Geometries Ltd. Finite element analyses considering material anisotropy were then carried out for RP prototypes with various building directions. Effect of the building direction on the mechanical strength was investigated through the analysis, and compared with experimental results.

• Journal of Fashion Business
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• v.27 no.6
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• pp.37-46
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• 2023

This study aims to develop workwear prototypes by applying a systematic approach considering the characteristics of workwear. A case study was conducted before this study to derive workwear's four characteristics: 'Ergonomic Pattern-Making, Certified Fabric, Specialized Color, and Customized Details.' a prior study proposed the integrated framework combining these characteristics with the FEA model. The new framework identified that these characteristics are considered in terms of functionality, expression, and aesthetics; it can increase workers' satisfaction and meet the market demand without concentrating on only particular aspects. Before prototype production, the requirements for each characteristic of workwear were analyzed through theoretical research of previously published related papers. The study primarily gathered workwear requirements data and sources from consumer satisfaction surveys and investigations into the wearing conditions of work clothes. When considering all aspects of pattern-making, fabric, color, and detail in functionality, 'comfort movement, body protection, improved work efficiency' were identified as necessary. Expressive requirements were fundamental, including 'reflecting the wearer's preferences, expressing a sense of belonging and identity. It was clear that incorporating design elements and applying current trends to the aesthetic requirements of work clothes was necessary. Four prototypes comprised two top and bottom sets and two overalls using these requirements. The framework was used throughout the entire process of planning, producing, and evaluating prototypes, and through this, the results fulfilled the requirements. This study is significant because it produced workwear prototypes using an integrated approach that considered functional, expressive, and aesthetic aspects.

• Journal of Korea Foundry Society
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• v.20 no.5
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• pp.330-335
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• 2000

Functional metal prototypes are often required in numerous industrial applications. These components are typically needed in the early stage of a project to determine form, fit and function. Recent R/P(Rapid Prototyping) part are made of soft materials such as plastics, wax, paper, these master models cannot be employed durable test in real harsh working environment. Parts by direct metal rapid tooling method, such as laser sintering, by now are hard to get net shape, pores of the green parts of powder casting method must be infiltrated to get proper strength as tool, and new type of 3D direct tooling system combining fabrication welding arc and cutting process is reported. But a system which can build directly 3D parts of high performance functional material as metal park would get long period of system development, massive investment and other serious obstacles, such as patent. In this paper, through the rapid tooling process as silicon rubber molding using R/P master model, and fabricate wax pattern in that silicon rubber mold using vacuum casting method, then we translated the wax patterns to numerous metal tool prototypes by new investment casting process combined conventional investment casting with rapid prototyping & rapid tooling process. With this wax-injection-mold-free investment casting, we developed new investment casting process of fabricating numerous functional metal prototypes from one master model, combined 3-D CAD, R/P and conventional investment casting and tried to expect net shape measuring total dimension shrinkage from R/P pare to metal part.

• Transactions of Materials Processing
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• v.11 no.4
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• pp.323-331
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• 2002

The combination of rapid prototyping(RP) and rapid tooling(RT) has a potential for rapid manufacturing of three-dimensional parts. In the present study, a new RP system transfer type Variable Lamination Manufacturing using Expandable Polystyrene Foam (VLM-ST), is proposed to fabricate net shapes of three-dimensional prototypes. Various three-dimensional parts, such as a knob shape and a human head shape, are manufactured by the VLM-ST apparatus. In addition, a new rapid tooling technology, which utilizes a room temperature vulcanizing (RTV) molding technique and a triple reverse process technique, is proposed to manufacture net shapes of three-dimensional plastic parts using the prototypes of VLM-ST. A plastic part of the knob shape is produced by the proposed RT technology. The combination of the proposed RP and RT enables the manufacture of a plastic knob within two days.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.190-194
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• 2001

The integration of rapid prototyping and tooling has the potential for the rapid net shape manufacturing of three-dimensional parts with geometrical complexity. In this study, a new rapid prototyping process, transfer type of Variable Lamination Manufacturing (VLM-ST), was proposed to manufacture net shape of 3-D prototypes. In order to examine the efficiency and applicability of the proposed process, various 3-D parts, such as a world-cup logo, and extruded cross and a knob shape, were fabricated on the apparatus. In addition, the new rapid tooling process, which is a triple reverse process, was proposed to manufacture of 3-D functional part using VLM-ST prototypes and the plastic part of the knob shape was produced by the new rapid tooling process.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.52-57
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• 1999

Funtional metal prototypes are often required in numerous industrial applications. These components are typically needed in the early stage of a project to determine form, fit and function. Recent R/P(Rapid Prototyping) part are made of soft materials such as plastics, wax, paper, these master models cannot be employed durable test in real harsh working environment. Parts by direct metal rapid tooling method, such as laser sintering, by now are hard to get net shape, pores of the green parts of powder casting method must be infiltrated to get proper strength as tool, and new type of 3D direct tooling system combining fabrication welding arc and cutting process is reported by song etc. But a system which can build directly 3D parts of high performance functional material as metal part would need long period of system development, massive investment and other serious obstacles, such as patent. In this paper, through the rapid tooling process as silicon rubber molding using R/P master model, and fabricate wax pattern in that silicon rubber mold using vacuum casting method, then we tranlsated the wax patterns to numerous metal prototypes by new investment casting process combined conventional investment casting with rapid pototyping & rapid tooling process. with this wax-injection-mold-free investment casting, we developed new investment casting process of fabricating numerous functional metal prototypes from one master model, combined 3-D CAD, R/P and conventional investment casting and tried to expect net shape measuring total dimension shrinkage from R/P part to metal part.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.428-432
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• 2003

The technical combination of RP and RT has a potential for rapid manufacturing of three-dimensional parts. In the present work a new RP system, $VLM-_{ST}$, is proposed to manufacture net shapes of 3D prototypes. ㅁ human head shape and a kob shape are manufactured by the $VLM-_{ST}$ apparatus. In addition, a new RT technology, which utilizes a RTV molding technique and a triple reverse process technique, is proposed to manufacture net shapes of 3D plastic parts using prototypes of $VLM-_{ST}$. A plastic part of the knob shape os produced by the proposed RT technology. The combination of the proposed RP and RT enables the manufacturing of a plastic knob within two days.

• Korean Journal of Computational Design and Engineering
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• v.7 no.2
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• pp.96-101
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• 2002

Rapid Prototyping (RP) technology has been advanced to fabricate initial prototypes from various materials. Stratasys′ Fused Deposition Modeling (FDM) is one of the typical RP processes that provide functional prototypes of ABS plastic. In order to predict the behavior of final ABS parts, it is critical to understand the material properties of the raw FDM process material, and the effect that FDM build parameters have on the FDM part. In this paper, we seek to characterize the properties of ABS parts fabricated by the FDM 1650. Using the Design of Experiment (DOE) approach, the process parameters of FDM, such as raster orientation, air gap, bead width, color, and model temperature were examined. Tensile strengths of crisscross specimens, 〔45°/-45°〕, cross specimens, 〔0°/90°〕, and directionally fabricated tensile specimens (〔0°〕 and 〔90°〕) were measured and compared with the injection molded FDM-ABS P400 material. For the FDM parts made with a -0.003"air gap, the typical tensile strength ranged between 50 percent and 83 percent of the strength of injection molded ABS P400. From the experiments, a couple of build rules for designing FDM parts were obtained.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.755-758
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• 2000

Rapid prototyping is one of the most important technology for 21th century industry. To overcome the limitation of the material and function, Functional Prototype Development(FPD) concept is newly proposed. Wide function is necessary such as mechanical, optical, chemical and electrical property in order to solve broad requirements of the industry. The process of FPD has more than two conventional processes based on fusion technology and the FPD system is integrated with the interdisciplinary, interfacing and intelligent concepts. This paper shows some representative achievements such as optic coloring prototypes, electric multi layer printed circuit broad(MLB) and MEMS using electrostrictive polymer. Finally, we confirmed that FPD has a great possibility which can be applied in broad industry and will be a powerful tool in near future.