• Journal of the Korean Society of Clothing and Textiles
• /
• v.41 no.3
• /
• pp.468-486
• /
• 2017

In this study, three kinds of wearable fashion prototypes were developed using 3D printers with the goal of developing a practical production method for daily clothes. Prototypes were modeled using Rhinoceros software and developed using FDM 3D printers and TPU filaments. The results of this study are as follows. First, it confirmed the possibility of FDM-type entry-level 3D printers as a tool to develop wearable fashion products. Second, TPU filaments that are soft and ductile are highly likely to be used as a clothing material. Third, patterns designed through the 3D modeling process can be sampled directly to a 3D printer and easily corrected and supplemented. Fourth, it was confirmed that TPU prints of about 1.00mm thickness can be sewn with fabric using sewing machines through the development of 'Prototype 1' and 'Prototype 2'; in addition, hand stitching is also possible. Fifth, as in the case of 'Prototype 3', it is possible to fabricate a garment fit enough to the body if the clothing configuration is designed to connect the basic module using TPU filaments. In the future, the development of wearable fashion prototypes using various materials and 3D printing technology will help diversify everyday clothes.

• Imaging Science in Dentistry
• /
• v.51 no.1
• /
• pp.41-47
• /
• 2021

Purpose: This study aimed to compare the accuracy of 3-dimensional(3D) printed models derived from multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) systems with different fields of view (FOVs). Materials and Methods: Five human dry mandibles were used to assess the accuracy of reconstructions of anatomical landmarks, bone defects, and intra-socket dimensions by 3D printers. The measurements were made on dry mandibles using a digital caliper (gold standard). The mandibles then underwent MDCT imaging. In addition, CBCT images were obtained using Cranex 3D and NewTom 3G scanners with 2 different FOVs. The images were transferred to two 3D printers, and the digital light processing (DLP) and fused deposition modeling (FDM) techniques were used to fabricate the 3D models, respectively. The same measurements were also made on the fabricated prototypes. The values measured on the 3D models were compared with the actual values, and the differences were analyzed using the paired t-test. Results: The landmarks measured on prototypes fabricated using the FDM and DLP techniques based on all 4 imaging systems showed differences from the gold standard. No significant differences were noted between the FDM and DLP techniques. Conclusion: The 3D printers were reliable systems for maxillofacial reconstruction. In this study, scanners with smaller voxels had the highest precision, and the DLP printer showed higher accuracy in reconstructing the maxillofacial landmarks. It seemed that 3D reconstructions of the anterior region were overestimated, while the reconstructions of intra-socket dimensions and implant holes were slightly underestimated.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.11
• /
• pp.96-102
• /
• 2019

Reverse engineering involves duplicating a physical part by measuring and analyzing its physical dimensions, features, and material properties. By combining reverse engineering with three-dimensional (3D) printing, engineers can simply fabricate and evaluate functional prototypes. This design methodology has been attracting increasing interest with the advent of the Fourth Industrial Revolution. In the present study, we apply reverse engineering and 3D printing technologies to evaluate a fabricated automotive inner ring prototype. Through 3D printing, inner rings of various densities were prepared. Their physical dimensions were measured with a 3D scanning system. Of our interest was the effect of inner ring density on the physical dimensions of the fabricated prototype. We compared the design dimensions and physical dimensions of the fabricated prototypes. The results revealed that even the 20% density of inner ring was effective for 3D printing in terms of satisfying the design requirements.

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

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

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

• Fashion & Textile Research Journal
• /
• v.26 no.1
• /
• pp.65-77
• /
• 2024

This study aimed to propose effective ways to integrate CLO into educational settings by conducting a comparative analysis of pattern functions in YUKA and CLO, specifically focusing on skirt prototypes and variations. CLO, being a 3D virtual sample CAD tool, is mainly used in education to facilitate the creation of 3D virtual clothing. In order to explore the applicability of CLO's pattern functions in pattern education, CAD education experts were asked to produce two types of skirt prototypes and two skirt variations. Subsequently, in-depth interviews were conducted. In addition, the skirt pattern creation process was recorded on video and used for comparative analysis of YUKA and CLO pattern functions. The comparison revealed that CLO provides the pattern tools necessary for drafting skirt prototypes. The learning curve for acquiring the skills necessary for drafting and transforming skirt prototypes was found to be relatively shorter for CLO compared to YUKA. In addition, due to CLO's surface-based pattern drawing method, it is difficult to move or copy only specific parts of the outline, and there are some limitations in drawing right angle lines. In the pattern transformation process, CLO's preview function proved to be advantageous, and it was highly rated on user convenience due to the intuitive UI. Thus, CLO shows promise for pattern drafting education and is deemed to have high scalability as it is directly linked to 3D virtual clothing.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.7
• /
• pp.270-276
• /
• 2020

3D printing is an additive manufacturing technology that can produce complex shapes in a single process for a range of materials, such as polymers, ceramics, and metals. Recent 3D printing technology has developed to a level that enables the mass-production through an improvement of the printing speed and the continuous development of applicable materials. In this study, 3D printing technology using a laser was applied to manufacture a heat exchanger for an air compressor in a railway vehicle. First, the optimal design of the heat exchanger was carried out by focusing on weight reduction and compactness as a shape suitable for 3D printing. Based on the design derived, heat exchanger prototypes were made of AlSi10Mg alloy material by applying the SLM technique. Moreover, the manufactured prototypes were attached to an existing air compressor, and the heat exchange performance of the compressed air was tested. The test results of the 3D printed prototypes showed a heat exchange performance of approximately 80% and 85% at low and high-pressure, respectively, compared to the existing heat exchanger. From the 𝓔-NTU method results with an external cooling air condition similar to that of the existing heat exchanger, the calculated heat transfer amount of 3D printed parts showed similar performance compared to the existing heat exchanger. As a result, the 3D printed heat exchanger is lightweight with good performance.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.23 no.1
• /
• pp.84-91
• /
• 2013

Ultrasonic flip-chip bonding needs a precise bonding tool which delivers ultrasonic energy into chip bumps effectively to use the selected resonance mode and frequency of the horn structure. The bonding tool is excited at the resonance frequency and the input and output ports should locate at the anti-nodal points of the resonance mode. In this study, we propose new design method with topology optimization for ultrasonic bonding tools. The SIMP(solid isotropic material with penalization) method is used to formulate topology optimization and OC(optimal criteria) algorithm is adopted for the update scheme. MAC(modal assurance criterion) tracking is used for the target frequency and mode. We fabricate two prototypes of ultrasonic tools which are based on 3D optimization models after reviewing 2D and 3D topology optimization results. The prototypes are satisfied with the ultrasonic frequency and vibration amplitude as the ultrasonic bonding tools.

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