대면적 도광판 성형을 위한 R-I/C Molding 공정 기술

김성훈(S. H. Kim),김종섭(J. S. Kim),진민영(M. Y. Jin) 한국소성가공학회 2012 한국소성가공학회 학술대회 논문집 Vol.2012 No.10

The recent LCD TV market has made efforts to produce thinner, brighter, and clearer products, and experienced the rapid light source replacement from a line source of light CCFL to a point source of light LED. In particular, LGP(Light Guiding Panel) among key parts composing BLU(Back Light Unit) has limits of the injection molding technology as well as the mold design, its processing and manufacturing technology so that it is hard to produce large LGP over 40 inch. The initial injection test was conducted to improve production stabilization and productivity for these large-area LGPs (light guide panels) which are over 40 inches with injection molding. And by analyzing several results drawn from this, the optimization of injection molding process technology was performed. As a result, process technology was established to manufacture and produce large-area LGPs with 40 inches by injection molding. And through such injection molding process technology, it was possible to secure mass production. It is expected to enter various industrial areas (lighting area/advertising area, etc.) with the optimization of large-area thin plate molding process technology.

Ir-RE 코팅 대비 자장여과필터방식을 이용한 비구면 유리 렌즈용 초경합금(WC)표면의 ta-C 박막 코팅 성능 개선 연구

정경서,김승희 한국산학기술학회 2019 한국산학기술학회논문지 Vol.20 No.12

작은 굴절률 및 높은 굴절률을 갖는 저 분산 렌즈에 대한 요구가 증가함에 따라, 높은 내열성 및 내마모성을 갖는 이형성 보호 필름에 대한 필요성이 증가하고 있다. 그러나 광학 산업은 비구면 유리 렌즈 성형에 사용되는 이형 보호 필름의 제조 공정 및 품질 표준에 대한 명확한 표준을 아직 확립하지 못했다. 이 기술은 광학 렌즈를 제조하는 각 회사의 노하우로 취급된다.  본 연구에서는 FCVA (Filtered Cathode Vacuum Arc) 기반 ta-C 박막 코팅의 이온 에칭, 각 소스 및 필터부의 마그네트론 및 아크 전류, 바이어스 전압의 최적화에 관한 실험을 수행하였다. 그 결과, 코팅 성능 측면에서, 이리듐- 레늄 합금 박막 스퍼터링 제품 대비 필름 두께가 약 50% 얇고, 경도는 약 20%, 박막의 접착 강도는 약 40 % 개선된 것으로 측정되었다. 본 연구의 박막 코팅 공정 결과는 금형 이형 박막층의 최소 기계적 특성 및 품질 확립을 위한 유리 렌즈의 개발 및 활용에 크게 기여할 것으로 사료된다. The demand for a low dispersion lens with a small refractive index and a high refractive index is increasing, and accordingly, there is an increasing need for a releasable protective film with high heat resistance and abrasion resistance. On the other hand, the optical industry has not yet established a clear standard for the manufacturing process and quality standards for mold-releasing protective films used in aspheric glass lens molding. Optical lens manufacturers treat this technology as proprietary information. In this study, an experiment was conducted regarding the optimization of ion etching, magnetron, and arc current at each source and filter part, and bias voltage in FCVA (filtered cathode vacuum arc)-based Ta-C thin film coatings. This study found that compared to iridium-rhenium alloy thin film sputtering products, the coating conditions were improved by approximately 50%, 20%, and 40% in terms of thickness, hardness, and adhesive strength of the film, respectively. The thin-film coating process proposed in this study is expected to contribute significantly to the development and utilization of glass lenses, which will help enhance the minimum mechanical properties and quality of the mold-release thin film layer required for glass mold surface forming technology.

퍼지논리에 의한 최적 성형조건 결정 시스템에 관한 연구

강성남,허용정 한국산학기술학회 2002 한국산학기술학회논문지 Vol.3 No.1

사출성형에서 제품의 최종 품질에 영향을 미치는 중요한 인자들 중외 하나는 사출압력이다. 전통적으로 현장의 사출전문가는 오래된 현장 경험을 바탕으로 사출압력을 결정한다. 그러나 비전문가에게는 제품의 크기, 형상 그리고 사출공정의 전반적인 과정을 고려한 적절한 사출압을 결정하기가 쉽지 않다. 본 연구에서는 퍼지 논리(fuzzy logic)를 이용하여 제품도면에 나와 있는 제품두께와 유동길이를 알면 쉽게 초기 사출압을 결정할 수 있도록 전문가의 경험을 규칙베이스화 하였다. 규칙베이스를 구성하기 위해서 현장 전문가들을 인터뷰하고 설문조사를 한 후 기술적인 문서를 작성하여야 하지만 본 연구에서는 사출성형 해석 프로그램인 C-Mold를 이용하여 수 차례의 시뮬레이션을 반복 수행하여 규칙베이스를 구성하였다. A Short shot is a molded part that is incomplete because insufficient material was injected into the mold. Any factors that increase the resistance of polymer melt to now or prohibit delivery of sufficient material into the cavity can cause a short shot. Inappropriate injection pressure is one of the most common factors which cause a short shot. Conventionally, domain experts in injection molding decide and modify the pressure based on their experience. It is difficult for a non-expert to decide the pressure properly with the considerations such as a part dimension, shape, and other processing variables. In this study, fuzzy algorithm is proposed to standardize the empirical determination of the pressure so thai not only the experts but also non-experts can find the appropriate injection pressure easily. To acquire the more accurate results, domain experts should be interviewed and then technical documents which are collected from the experts should be restored in the fuzzy rule base. But in this study, simulations have been done by using C-MOLD to settle the rule base because it takes much time and also it's difficult to meet and interview the experts.

CAE를 이용한 플라스틱 사출성형품 결함에 대한 연구

이종훈(Jong-Hoon Lee),전우청(Woo-Cheong Jeon) 산업기술교육훈련학회 2010 산업기술연구논문지 (JITR) Vol.15 No.4

This paper deals with investigations into the testing of analysis with CAE(mold flow). It has been carried out to study the possibility before the injection molding. The results indicate that analysis characteristic is very important of injection molding condition with distinctly different from between heat temperature of resin and molding. especially we found gravity out about size and position of the first gate. So there are not defects of molding on analysis with all optimum condition as before and we will apply improvement data to injection molding system.

공정시스템,이동현상,화학공정안전 : 고무사출성형의 적정설계

이은주 ( Eun Ju Lee ),임광희 ( Kwang Hee Lim ),부타이지양 ( Vu Tai Giang ) 한국화학공학회 2011 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.49 No.1

K사의 고무 사출성형에 있어서 애로사항인 등속조인트 부트(boots)의 크랰 (crack) 발생 등의 문제점을 해결하기 위하여, 상용 CAE 프로그램인 MOLDFLOW(Ver. 5.2)를 이용한 전산모사를 수행하여 적정금형설계를 도출하고 적정작업조건을 구축하였다. 그 결과 크랰의 발생 원인은 크랰이 발생하는 위치에 형성되는 weld 및 meld line의 형성 때문 이고, 또한 크랰 이 발생하는 위치에서의 가류(curing)가 불완전한 것이 확인되었다. 이와 같은 weld 및 meld line의 형성을 방지하기 위해서 게이트(gate)의 위치를 변경하고 최적위치에 설계함으로써, 유동선단(melt front)의 충돌 또는 수지흐름의 만남을 최소화하는 충전패턴(fill pattern)을 형성하고 부트 안쪽 하단의 크랰 발생을 방지하였다. Weld 및 meld line과 에어트랩(air trap) 불량이 가장 큰 게이트 위치는 각각 최적 게이트위치를 기준으로 서로 정반대 방향임이 관찰 되었다. 한편 몰드(mold)의 온도를 170℃로 유지하게 함으로써 크랰이 발생했던 위치에 가류조건을 만족시켰다. The optimum mold design and the optimum process condition were constructed upon executing process simulation of rubber injection molding with the commercial CAE program of MOLDFLOW (Ver. 5.2) in order to solve the process-problems of K company relating to cracks, which occurs at the inner cavity wall of C. V. joint boots. As a result it was confirmed that the real cracks occurs at the exactly same position of the cavity as exhibits the defects of weld and meld line and unsatisfactory curing according to the result of simulation. In order to prevent the occurrence of weld and meld line at the defect-position, the location of gate was altered to the optimum position of the cavity. Consequently the filling pattern was established to minimize the degree of the melt-fronts confronting or the melt-flows melding to prevent the occurrence of weld and meld line at the defect-position. It was observed that both gate-positions to maximize the degree of the formation of weld and meld line and air traps are located, respectively, in opposite direction each other with reference to the optimum gate position. In addition, the temperature of mold was raised by 10 °C and maintained at 170 °C for satisfactory curing.

인삼 잿빛곰팡이병의 친환경방제를 위한 유기농업자재 선발

김우식,김종성,박지성,안인,박경훈,김기홍 한국약용작물학회 2015 한국약용작물학회지 Vol.23 No.6

Background : To control ginseng gray mold, farmers have mainly used inorganic chemical based fungicides. The recent emergence of fungicide resistance has reduced the effectiveness of such control methods. Such pesticides also carry additional problems, such as diffuse pollution. Methods and Results : Six treatments of organic agricultural materials were tested for control of ginseng gray mold, CAPW (Chrysophanic acid + Phytoncide +Wood vinegar), EmEWV (Emodin + Ethanol +Wood vinegar), CEWV (Curcumin + Eugenol +Wood vinegar), Bacillus subtilis, soybean oil and sulfur. The control effect for gray mold by a single application of the agrochemical fungicide industrial Fenhexamid wettable powder (WP) was 84.4%. The control effect by CAPW, EmEWV and CEWV varied between 52.7 - 64.9%. The control effect by B. subtilis, soybean oil, and sulfur were 32.9 - 59.2%. Conclusions : In the field tests, CAPW showed the highest control effects when used before, and at first stage of disease incidence, against ginseng gray mold.

Injection molded mechanoluminescent polymer composites

Kim, Hyeon Kyeong,Song, Young Seok Elsevier 2018 Composites science and technology Vol.168 No.-

<P><B>Abstract</B></P> <P>The aim of this study is to demonstrate the fabrication process of mechanoluminescent (ML) composites. As an ML component, ZnS:Cu was employed in the composite. ML powders embedded thermoplastic polyurethane (TPU) composites were prepared using injection molding. A wheel was considered as a final target application of the composite material. The manufacturing process and resulting mechanical behavior of the wheel were modeled numerically. The morphological, rheological, thermal, and mechanical properties of the composites were analyzed experimentally. As the particle content and mechanical stimulus imposed on the specimen increased, the induced ML was enhanced significantly. We showed the possibility of applying ML particles embedded composites to real engineering products.</P>

자동차용 TPE BOOT의 C4금형 개발에 관한 연구

이예환(Y.H. Lee),신상우(S.W..Shin),이종원(J.W. Lee),성지현(J. H. Sung),김우성(W.S. Kim),이상곤(S.K. Lee),김강은(K.E. Kim),김양곤(Y.G. Kim) 한국생산제조학회 2014 한국생산제조시스템학회 학술발표대회 논문집 Vol.2014 No.4

수지 및 탄소섬유 함유량에 따른 C-SMC 복합재료 물성 연구

서대경(Dae-kyung Seo),양석곤(Suk-gon Yang),김기영(Ki Young Kim),박민기(Min Gee Park),박대규(Dae-gyu Park),이은하(Eun-ha Lee),김용태(Yong-tae Kim),배진석(Jin-Seok Bae) 한국염색가공학회 2020 韓國染色加工學會誌 Vol.32 No.4

Application of ta-C Coating on WC Mold to Molded Glass Lens

Woo-Young Lee,Ju-hyun Choi 한국트라이볼로지학회 2019 한국윤활학회지(윤활학회지) Vol.35 No.2

We investigated the application of tetrahedral amorphous carbon (ta-C) coatings to fabricate a glass lens manufactured using a glass molding process (GMP). In this work, ta-C coatings with different thickness (50, 100, 150 and 200 nm) were deposited on a tungsten carbide (WC-Co) mold using the X-bend filter of a filtered cathode vacuum arc. The effects of thickness on mechanical and tribological properties of the coating were studied. These ta-C coatings were characterized by atomic force microscopy, scanning electron microscopy, nano-indentation measurements, Raman spectrometry, Rockwell-C tests, scratch tests and ball on disc tribometer tests. The nano-indentation measurements showed that hardness increased with an increase in coating thickness. In addition, the G-peak position in the Raman spectra analysis was right shifted from 1520 to 1586 cm<SUP>−1</SUP>, indicating that the sp³ content increased with increasing thickness of ta-C coatings. The scratch test showed that, compared to other coatings, the 100-nm-thick ta-C coating displayed excellent adhesion strength without delamination. The friction test was carried out in a nitrogen environment using a ball-on-disk tribometer. The 100-nm-thick ta-C coating showed a low friction coefficient of 0.078. When this coating was applied to a GMP, the life time, i.e., shot counts, dramatically increased up to 2,500 counts, in comparison with Ir-Re coating.