사출압축성형을 적용한 고해상도 폰 카메라용 플라스틱 렌즈 개발

이호상(Ho Sang Lee),전원택(Won Taek Jeon),김성우(Sung Woo Kim) 대한기계학회 2013 大韓機械學會論文集A Vol.37 No.1

본 논문의 목적은 사출압축성형을 적용하여 13 메가 픽셀을 갖는 휴대폰 카메라용 플라스틱 비구면 렌즈를 개발하는데 있다. 사출압축성형 실험을 위하여 이동 가능한 상부 형판과 4 개의 스프링을 사용하여 금형이 제작되었다. 두께비 2 를 갖는 비구면 렌즈를 대상으로 캐비티 충전 실험을 수행한 결과, 일반 사출성형에서는 웰드라인이 발생하였으나, 0.3㎜ 의 압축스트로크가 적용된 사출압축성형에서는 웰드라인이 발생하지 않았다. 또한 미성형 실험을 통하여 얻은 충전패턴은 해석결과와 잘 일치하였다. 복굴절은 압축스트로크가 증가함에 따라 감소하였으며, 사출압축성형에서 발생한 복굴절은 일반 사출성형에 의한 값에 비하여 매우 낮고 균일한 분포를 나타냈다. 그리고 4 장의 플라스틱 렌즈로 구성된 조립체의 평균 복굴절은 장착되는 렌즈의 방향에 의하여 크게 영향을 받았다. This study aims to develop a plastic aspheric lens for a 13-megapixel mobile phone camera by injectioncompression molding. A mold for injection-compression molding experiments was fabricated with a movable upper plate and four springs. During cavity filling for an aspheric lens with a thickness ratio of 2, a weldline was formed under conventional injection molding, whereas no weldline was formed under injection-compression molding with a compression stroke of 0.3 ㎜. The flow patterns were in good agreement with the simulation results. The birefringence decreased as the compression stroke increased, and the birefringence produced by injection-compression molding was very low and more uniform compared with that produced by injection molding. In addition, the bulk birefringence of an assembly composed of four plastic lenses was significantly affected by the orientation of the lenses to be mounted.

사출압축성형을 이용한 자동차용 도어그립 필름인서트성형

이호상(Ho Sang Lee),유영길(Young Gil Yoo),김태안(Tae An Kim) 대한기계학회 2014 大韓機械學會論文集A Vol.38 No.7

자동차용 도어그립을 대상으로 하여 3 차원 엠보 패턴이 인쇄된 필름을 적용한 인서트성형을 구현하기 위하여 사출압축성형을 사용하였다. 진공금형을 제작하여 필름 열성형을 하였으며, 필름인서트성형을 위하여 사출압축금형을 개발하였다. 3 개의 압력센서를 설치하여 금형 캐비티압력을 측정하였으며, 다양한 압축스트로크와 토글속도에 대한 사출압축성형 실험을 수행하여, 공정조건이 캐비티 압력과 엠보 패턴의 높이에 미치는 영향을 고찰하였다. 압축스트로크 0.9mm 와 느린 토글속도에서 엠보 패턴의 유지율이 높게 나타났다. 또한 엠보패턴이 최대 높이를 갖기 위한 공정조건은 캐비티 압력의 적분값이 최소가 되는 조건과 거의 동일하였다. 사출압축성형을 사용하여 엠보 패턴이 인쇄된 소프트한 촉감을 갖는 플라스틱 제품을 구현할 수 있다. Injection-compression molding was used for film insert molding of an automotive door grip using films with three-dimensional embossed patterns. A vacuum mold was fabricated for vacuum-assisted thermoforming of the film, and an injection-compression mold was developed for film insert molding. Three pressure transducers were installed inside the mold cavity to measure cavity pressures. Injection-compression molding experiments under various compression strokes and toggle speeds were performed to investigate their effects on the cavity pressure and heights of the embossed patterns. The compression stroke of 0.9mm and low toggle speed resulted in a higher degree of conservation of embossed patterns. Additionally, the processing conditions for the maximum heights of embossed patterns were almost similar to those for minimum integral value of cavity pressures. The injection-compression molding process presents the opportunity to impart a soft-touch feeling of plastic parts printed with embossed patterns.

자동차용 안개등 커버의 사출성형 품질 향상을 위한 2 단계 설계 최적화

박창현(Chang-Hyun Park),안희재(Hee-jae Ahn),최동훈(Dong-Hoon Choi),표병기(Byung-Gi Pyo) 대한기계학회 2010 大韓機械學會論文集A Vol.34 No.8

사출성형에서 사출압력은 제품의 특성을 결정하는 주요인자이므로 성형품의 품질 향상을 위해 사출압력은 최소화 되어야 한다. 또한 휨 변형과 웰드라인은 사출성형에서의 대표적인 불량요인으로 사출성형품의 품질 향상을 위해 방지되어야 한다. 본 논문에서는 사출성형품의 품질 향상을 위해 설계 절차를 2 단계로 나눈다. 첫 번째 설계에서는 공정조건을 제어하여 사출압력과 휨 변형을 최소화 하기 위해 직교배열표를 이용한 전산실험을 수행하고 이를 이용하여 근사모델을 생성한 후 최적설계를 수행한다. 두 번째 설계에서는 유동경로 개선을 통한 웰드라인의 발생을 방지하기 위해 해석모델의 두께를 변경하고 웰드라인 발생 유무를 평가한다. 이러한 설계절차를 통해 사출압력과 휨변형을 최소화하면서 웰드라인을 방지하여 본 논문에서 제안한 설계방법의 유효성을 보이고자 한다. Injection pressure, an important factor in the filling procedure, should be minimized to enhance injection molding quality. In addition, warping deformation and weld lines, which are representative failures, should be avoided to enhance injection molding quality. To improve injection molding quality, the design procedure for an automotive fog blank cover is divided into two stages. In the first stage, we optimally obtain injection molding process variables that minimize injection pressure and warping deformation by using design of experiments, approximation and optimization techniques equipped in PIAnO (Process Integration, Automation and Optimization), a commercial PIDO (Process Integration and Design Optimization) tool. Then, we determine the thickness of the automotive fog blank cover that enables us to avoid generating weld lines. The design results we obtain in this study are found far better than those of the initial design, which demonstrates the effectiveness of our design method.

가정용 전자 제습기의 사출성형 해석

황지은(Ji-Eun Hwang),이동욱(Dong-Wook Lee),김종순(Jong-Soon Kim),강태호(Tae-Ho Kang),김인관(In-Kwan Kim),김영수(Young-Soo Kim) 한국기계가공학회 2006 한국기계가공학회 춘추계학술대회 논문집 Vol.2006 No.-

Injection molding is used for the purpose of low-cost and mass production. The filling, holding, cooling and ejecting processes of injection molding are put together. The purpose of this research is to predict injection molding processes and to suggest there by that optimum injection molding conditions. We performed the CAE(Computer Aided Engineering) of injection molding to optimize the injection molding processes. A prediction through CAE, such as fill pattern, pressure, weldlines, temperature at flow front are applied and compared to real experiment.

사출성형기 실린더와 금형 캐비티의 실시간 모니터링을 이용한 사출성형공정 비교 분석

박형필(Hyung Pil Park),차백순(Baeg Soon Cha),태준성(Jun Sung Tae),최재혁(Jae Hyuk Choi),이병옥(Byung Ohk Rhee) 대한기계학회 2010 大韓機械學會論文集A Vol.34 No.10

최근 고품질 제품 생산을 위한 방법으로 센서를 이용한 사출공정모니터링 시스템이 적용되고 있다. 그러나 마이크로 금형, 광학용 금형 및 구조가 복잡한 금형에는 센서 설치가 어렵기 때문에, 공정 모니터링 시스템이 적용되기 어려운 단점이 있다. 본 연구에서는 금형과 사출성형기 노즐의 압력 을 측정하여 공정 모니터링 데이터의 정량적 지수를 정의하고, 성형품 중량에 대한 상관분석을 수행하여 노즐에 설치된 압력센서의 공정모니터링 적용성을 알아보았다. 또한 공정모니터링 데이터를 분석하여 다단사출속도, 보압 및 제한 사출 압력의 영향에 따른 사출성형기의 공정 제어 특성도 알아보았다. Recently, on-line process monitoring systems using sensors are being extensively used to produce highquality products. However, the difficulty in installing the sensors within the mold in the cases of micro-molds, optical molds, and molds with complex structures is a serious disadvantage of such process monitoring systems. In this study, the quantitative index of a process monitoring system was evaluated with the mold cavity pressure and the nozzle pressure for the injection molding machine. In order to evaluate the effect of the nozzle pressure, we performed correlation analysis for the weight of the molded product. We also examined the control characteristics of the injection molding machine by analyzing the effect of multistage injection speed, holding pressure, and injection pressure limit on the process monitoring data.

자동차용 Fog Blank Cover의 사출성형 품질 향상을 위한 2단계 설계 최적화

박창현(Chang-Hyun Park),안희재(Hee-jae Ahn),최동훈(Dong-Hoon Choi),표병기(Byung-Gi Pyo) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.3

사출성형에서 사출압력은 제품의 특성을 결정하는 주요인자이므로 사출압력은 최소화 되어야 한다. 또한 휨 변형과 웰드라인은 사출성형에서의 대표적인 불량요인으로 사출성형품의 품질 향상을 위해 방지되어야 한다. 본 논문에서는 사출성형품의 품질 향상을 위해 설계 절차를 2 단계로 나눈다. 첫 번째 설계에서는 공정조건을 제어하여 사출압력과 휨 변형을 최소화하기 위해 직교배열표를 이용한 전산실험을 수행하고 이를 이용하여 근사모델을 생성 한 후 최적설계를 수행 한다. 두 번째 설계에서는 유동경로 개선을 통한 웰드라인의 발생을 방지하기 위해 해석 모델의 두께를 변경하고 웰드라인 발생 유무를 평가한다. 이러한 설계 절차를 통해 사출압력과 휨 변형을 최소화하면서 웰드라인을 방지하여 본 논문에서 제안한 설계 방법의 유효성을 보이고자 한다. Injection pressure, an important factor in filling procedure, should be minimized to enhance injection molding quality. In addition, warping deformation and weld lines, representative faulty factors, should be avoided to enhance injection molding quality. To solve the optimization problem posed, design optimization procedure is divided into two stages. In the first stage, we optimally obtained injection molding process variables that minimize injection pressure and warping deformation by using design of experiments, approximation and optimization techniques equipped in PIAnO(Process Integration, Automation, and Optimization), a commercial PIDO(Process Integration and Design Optimization) tool. Later, we determined the best thickness of injection molding part to avoid generating weldlines. Finally, we obtained optimization results, which could demonstrate the effectiveness of our design method.

발포사출공정 중 스킨 형성에 따른 사출시간 선정에 관한 연구

서봉현(B.H. Seo),노상호(S.H. Noh),진광진(K.J. Jin),김상민(S.M. Kim),박대림(D.L. Park),박상언(S.U. Park) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

Foam injection molding process has the advantage that it can easily achieve lightweight by create cells inside plastic products. However, foam injection molding is more difficult to optimize process conditions than normal injection molding process. In particular, if the injection time is increased for the purpose of reducing the pressure to suppress stress, it is likely that the formation of skin layer because cooling will prevent the product from foaming properly. In this study, injection analysis and experiments was conducted to optimize process conditions to reduce pressure and maximize foaming performance during the foam injection molding process.

사출성형에서 유동선단과 구조물의 유동편차에 대한 연구

이용욱,한성렬 한국기계기술학회 2020 한국기계기술학회지 Vol.22 No.6

Plastic products molded by injection molding have become an essential element of our lives. In addition, plastics can replace parts that used to be metal in the past. Plastic molded products used as a part of a mechanical system require high precision. At the same time, the appearance quality of molded products is also an important evaluation factor. The appearance quality of a molded product is affected by injection molding conditions, plastic material fluidity, and the condition of the mold surface. In this study, the cause of the short shot of the dog house, which functions to assemble the plastic tailgate parts for automobiles, was analyzed. In order to solve the short shot problem of the dog house, the root thickness of the dog house, injection molding conditions, and fluidity of plastic materials were experimented. Through the injection molding experiment, it was found that when the dog house root thickness was increased from 0.8mm to 1.2mm, the filling amount of the doghouse part increased by 43% in experiment mold. These results were verified by injection molding analysis.

사출성형해석을 이용한 수직머시닝센터 ATC 툴 포트의 사출 게이트 위치에 따른 성형성 평가

이여울(Yu-Wool Lee),박철우(Chul-Woo Park),김진록(Jin-Rok Kim),최현진(Hyun-Jin Choi) 한국기계가공학회 2021 한국기계가공학회지 Vol.20 No.12

Injection molding is a manufacturing method of melting the polymer resin and injecting it into a mold to molding it into the desired form. Due to the short molding time and outstanding formability, complex products can be shaped with high precision and it is the most widely used polymer molding method. However, there may be areas that are not filled depending on the location of the injection gate where polymer resin is injected. Formability is determined by deformation and surface precision due to the impact of residual stress after molding. Hence, choosing the location of the injection gate is very important and molding analysis of injection molding is essential to reduce the cost of the mold. This study evaluated the injection formability based on the location of the injection gate of the vertical machining center ATC tool port using injection molding analysis and the results were compared and analyzed. Injection molding analysis was conducted on filling, packing, and deformation according to the location of the gate of the ATC tool port. From each injection gate location, filling time, pressure, and maximum deformation were compared. At gate 2, conditions of molding time and the location of the gate were far superior in production and quality. Gate 2 produced the smallest deformation of 0.779mm with the best quality.

인서트 변형을 고려한 배터리 케이스 사출 성형 해석

안동규(Dong-Gyu Ahn),김대원(Dea-Won Kim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

The objective of this paper is to investigate into the influence of the injection conditions on the insert deformation and the wall thickness of the injection part using the three-dimensional injection molding analysis. Full three-dimensional insert model was added to the injection molding analysis model to consider the effects of insert deformation during the injection molding process. In order to obtain the optimum injection molding condition with a minimum insert deformation, degree of experiments were utilized. From the results of the analyses, it was shown that the optimum injection condition is injection time of 1.6 sec, injection pressure of 30 ㎫a and packing time of 15 sec. In addition it was shown that the wall thickness is approached to target thickness when the core deformation is considered in the injection molding analysis.