• Title/Summary/Keyword: Mold industry

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Antifungal Activities on Organic Heritage Fungi and Antioxidative effect of Phellodendron amurense Extractives (황벽나무 추출물의 유기질 문화재 오염균에 대한 항균성 및 항산화 활성)

  • Hong, Jin-Young;Kim, Young-Hee;Jung, Mi-Hwa;Jo, Chang-Wook;Choi, Jung-Eun
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.5
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    • pp.54-61
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    • 2010
  • Antifungal and antioxidative activities of Phellodendron amurense extracts were investigated for use as a natural preservative. After separation of P. amurense into phloem, xylem, leaf and fruit each part was subjected to methanol extraction. Each MeOH extract was further fractionated with several solvents(n-hexane, methylene chloride and ethylacetate). Among the methanol extracts, extracts of phloem and leaf inhibited effectively the growth of mold fungi and rot fungi, respectively. Especially, ethylacetate fraction from phloem showed the highest growth inhibitory effects against fungi tested, such as P. citreonigrum H3, P. toxicarium H4, P. corylophilu H5, A. clavatus, P. osteatus, S. commune, and G. lucidum. The fractions of fruit, which had lower antifungal activities mostly than those of phloem, strongly inhibited rot fungi such as G. lucidum, T. versicolor, and T. palustris. Compared to ferulic acid which is well known antioxidant, ethylacetate fraction of fruit showed high antioxidative activities on concentration of 1 to $100{\mu}g/m{\ell}$ in DPPH radical scavenging activity. As a result, antifungal and antioxidative activities of P. amurense suggest that its extract and fraction have a possibility as conservative of cultural heritage because it might get conservation effects against deteriorating microorganisms of cultural heritage.

Development and Analysis of Dry Forming System for Innovation of Papermaking Technology

  • Kim, Jong-Min;Lee, Hak-Lae;Youn, Hye-Jung;Hwang, Min-Gu
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06b
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    • pp.181-190
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    • 2006
  • This study was conducted to develop dry forming technology and evaluate the properties of dry formed paper made from Hw-BKP. A dry forming mold (DFM) was developed to observe the phenomena of dry forming and evaluate the properties of formed papers. To upgrade the DFM a dry forming system (DFS) was developed. This DFS was designed to improve the formation of dry formed papers and enhance the productivity of dry forming. Dry forming gave papers with greater bulk and opacity than wet forming. Tensile strength of dry formed paper was greater than that of conventional wet formed handsheet when they were made from the same dry disintegrated fibers. But tensile strength of conventional wet formed handsheet made from beaten fiber was much greater than that of dry formed paper made from dry disintegrated fibers. When solvent dried beaten fibers were used in dry forming, the tensile strength of dry formed papers reached 73.5% of the wet formed handsheets made from beaten fiber. It showed that dry forming has a significant potential in improving strength properties when proper preparation of fibers and appropriate humidification, pressing, and drying processes are employed.

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Proposed Approaches on Durability Enhancement of Small Structure fabricated on Camera Lens Surface (카메라 렌즈 표면에 형성된 미세 패턴의 내구성 향상 기법 제안)

  • Park, Hong Ju;Choi, In Beom;Kim, Doo-In;Jeong, Myung Yung
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.5
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    • pp.467-473
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    • 2019
  • In this study, approached to improve durability of the multi-functional nano-pattern fabricated on the curved lens surface using nanoimprint lithography (NIL) was proposed, and the effects of the proposed methods on functionality after wear test were examined. To improve the mechanical property of ultraviolet(UV)-curable resin, UV-NIL was conducted at the elevated temperature around $60^{\circ}C$. In addition, micro/nano hierarchical structures was fabricated on the lens surface with a durable film mold. Analysis on the worn surfaces of nano-hole pattern and hierarchical structures and measurements on the static water contact angle and critical water volume for roll-off indicated that the UV curing process with elevated temperature is effective to maintain wettability by increasing hardness of resin. Also, it was found that the micro-scale pattern is effective to protect nano-pattern from damage during wear test.

Peculiar Fatigue Fracture Behavior of Ultrasonic Nanocrystal Surface Modified SCM435 (초음파 나노 결정 표면개질된 SCM435의 특이한 피로 파괴 특성)

  • Kim, Jae-Hoon;Yun, Seo-Hyun;Nam, Ki-Woo
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.2_2
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    • pp.239-245
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    • 2022
  • Using the fatigue limit (∆σunsm) and residual stress (σr) of the UNSM smooth specimen, the harmless maximum crack depth (ahlm) according to the crack aspect ratio (As) was evaluated. In addition, the relationship between the minimum crack depth (aNDI1, aNDI2) detectable by non-destructive inspection(NDI), the crack depth (a25, a50) that reduces the fatigue limit by 25% and 50%, and ahlm were evaluated. The harmless crack condition was determined by the deepest crack point (point A). Since ahlm is larger than a25 and a50, a25 and a50 can secure the safety and reliability of steel via UNSM. Because aNDI1 and aNDI2 are larger than a25 and a50, cracks in a25 and a50 cannot be detected by non-destructive testing. Therefore it is necessary to apply more precise NDI.

Numerical Analysis on the Ventilation System Improvement in Air Shot Blast Room (Air Shot Blast 작업실 내부 환기 시스템 개선에 관한 수치해석)

  • Chin, Do-Hun
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.5
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    • pp.861-868
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    • 2022
  • The purpose of this study is to design an effective atmospheric environment system through the design of the dust collection in the air shot room being operated in a domestic shipyard. The ventilation system in the current air shot room mostly uses a dust collecting filter to filter internal particles and releases them in the atmosphere. A conventional design was made too much. In order to prevent an error and draw an optimal design, Computational fluid dynamics (CFD) tried to be applied only to air shot room. In the advanced design technique, computer simulation was conducted to secure basic design data. In order to find the basic design of the ventilation system and the flow field in the air shot room at propeller mold workplace of a shipyard, the CFD was conducted. In the case of Model-1 as a conventional workplace, where air flows in the inlet due to the subatmospheric pressure generated by inhalation of an air blower and flows out to the outlet, a discharge flow rate was somewhat low, and there was the holdup zone in the room. In the case of Model-2 as an improved model, the ventilation system was improved in the Push-Pull type, and the holdup of the internal flow field was improved.

Damage Analysis of Leaf Spring for Transport Utility Vehicles (운송 차량용 판 스프링의 파손 해석)

  • Kim, Tae-Song;Kang, Seok-Hee;Kwon, Yung-Kug;Yun, Seo-Hyun;Nam, Ki-Woo
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.6_2
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    • pp.1047-1053
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    • 2022
  • The leaf spring for a truck absorbs shocks or vibrations from the road surface while driving with the elastic force of the material and prevents the shock from being transmitted to the vehicle body. It is subjected to cyclic stress, and fatigue fracture occurs frequently. This study analyzes fractured leaf spring from a 25 ton truck that has been operating for about a year. In the fractured portion, which is the origin of crack, inclusions were observed, and fatigue failure was caused by cyclic stress. In the stress calculation and FE analysis, the stress at the center of the leaf spring was obtained to be 54~65% of the yield strength of the base material and damaged material. It is most important to prevent the mixing of impurities in the steel manufacturing for leaf springs. The large stress portion of the leaf spring needs to introduce compressive residual stress by peening etc.

Evaluation of Harmless Crack Size of SCM822H Steel according to Shot Ball Size (쇼트 볼의 크기에 따르는 SCM822H 강의 무해화 균열크기 평가)

  • Jin-Woo Choi;Seo-Hyun Yun;Ki-Woo Nam
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.5
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    • pp.725-731
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    • 2023
  • In this study, the harmless crack size was evaluated using carburized, quenched-tempered SCM822H steel. The possibility of detecting cracks that reduce the fatigue limit by non-destructive inspection was evaluated. The conclusions obtained are as follows. The retained austenite of surface was reduced by SP. About 35% and 65% of the retained austenite on the surface were transformed into strain-induced martensite, increasing the hardness by 79HV and 122HV over the as-received material. The maximum compressive residual stresses introduced on the surfaces were -695 MPa and -688 MPa, respectively. The fatigue limit increased by 1.48 times and 1.67 times, respectively, compared to the as-received material. The harmless crack size of SP specimen was determined differently depending on the shot ball size.

Semiotic Analysis of Advertising Video Related to the Sustainability of Fast Fashion Brands (패스트 패션 브랜드의 지속가능성 관련 광고 영상에 대한 기호학적 분석)

  • Na Yeon Kil;Jaehoon Chun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.47 no.6
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    • pp.1057-1079
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    • 2023
  • This paper examines the use of semiotics for analyzing fashion advertisements in the fast fashion industry. While previous studies have explored the use of semiotics in various industries, the application of this theory in the fashion sector-especially regarding fast fashion's commercial videos related to sustainability-remains underexplored. The paper adopts Roland Barthes' Semiotics Theory to analyze the advertising videos related to the sustainability of major fast fashion brands such as H&M, MANGO, and ZARA. The research approach involved reviewing all commercial videos related to sustainability on these brands' official YouTube accounts and conducting comprehensive analyses of advertisements using the binary opposition analysis framework. The paper's findings indicate that these commercial videos serve as a platform to mold a brand's sustainability image and promote the notion that fast fashion brands are leading the charge toward sustainability, preparing for an unpredictable future, guiding people toward hope, and offering ultimate freedom. This research high-lights the necessity for a critical examination of advertising videos related to sustainability in the fast fashion industry to guarantee accountability and transparency.

Development of a injection molding automation system of busbar insert for the electric vehicle (전기 자동차 부스바 인서트 사출 자동화 시스템 개발)

  • Jong-Su Kim
    • Design & Manufacturing
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    • v.18 no.2
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    • pp.35-40
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    • 2024
  • Injection molding is a process widely used across various industries for molding plastics, and it is the most commonly applied process in root industries utilizing molds. Among the different types of injection molding, insert injection molding, where busbars are used as inserts, is increasingly being applied in the electric vehicle industry. However, currently, the insert injection molding process is manually performed, with workers placing insert components by hand before injection molding. This results in issues related to productivity, safety, and quality. Additionally, there is a growing demand for automation of such production lines due to hazardous working conditions, economic difficulties in the manufacturing industry, and the decline in the labor force caused by an aging population. This study focuses on the application of an automated system for the insert injection molding process used in electric vehicles. The development of an automated system for the transport and insertion of insert components, as well as the inspection and stacking processes after injection, has resulted in over a 25% improvement in productivity and more than a 27% reduction in defect rates.

Case Studies on Applications of Conformal Cooling Channel Based On DMT Technology (DMT기술을 활용한 형상적응형 냉각채널 적용 사례 연구)

  • Kim, Woo-Sung;Hong, Myung-Pyo;Park, Jun-Seok;Lee, Yun-Soon;Cha, Kyoung Je;Sung, Ji-Hyun;Jung, Min-Wha;Lee, Ye-Hwan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.3
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    • pp.9-14
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    • 2015
  • The Direct Metal Tooling (DMT) process is a kind of additive manufacturing processes, which is developed using various commercial steel powders, such as P20, P21, SUS420, and other non-ferrous metal powders. The DMT process is a versatile process that can be applied to various fields, such as the molding industry, the medical industry, and the defense industry. Among them, the application of the DMT process to the molding industry is one of its most attractive and practical applications, since the conformal cooling channel cores of injection molds can be fabricated at a slightly expensive cost by using the hybrid fabrication method of DMT technology compared with parts fabricated with machining technology. The main objectives of this study are to provide various characteristics of the parts made using the DMT process compared with the same parts machined from bulk materials and evaluate the performance of the injection mold equipped with a conformal cooling channel core fabricated using the hybrid method of the DMT process.