사출/압축 공정과 인서트 오버몰딩을 이용한 탄소복합소재 성형에 대한 연구

정의철,윤경환,홍석관,이상용,이성희,Jeong, Eui-Chul,Yoon, Kyung-hwan,Hong, Seok-Kwan,Lee, Sang-Yong,Lee, Sung-Hee 한국금형공학회 2020 한국금형공학회지 Vol.14 No.4

In this study, forming of carbon composite parts was performed using an injection/compression molding process. An impregnation of matrix is determined by ability of wet and flow rate between the matrix and reinforcement. The flow rate of matrix passing through the reinforcements is a function of permeability of reinforcement, a viscosity of matrix and pressure gradient on molding, and the viscosity of the matrix depends on the mold temperature, molding pressure and shear strain of matrix. Therefore, compression molding experiment was conducted using a heating mold in order to confirm the possibility of matrix impregnation. The impregnation of the matrix through the porosities between the woven yarns was confirmed by the cross-sectional SEM image of compression molded parts. An injection molding process was also performed at a short cycle time, high molding pressure and low mold temperature than those of compression experiment conditions. Deterioration of impregnation on the surface of molded parts were caused by these injection conditions and it could be the reason of decreasing the maximum tensile strength. In order to improve impregnation of matrix on the surface, injection/compression molding and insert-over molding were applied. As a result of applying injection/compression molding and insert-over molding, it was shown that the improvement of impregnation on the surface and the maximum tensile strength was increased about 2.8 times than the virgin matrix.

딥러닝 가속기 용 벡터프로세서 레지스터 파일 최적화

김보열(Bo Yeal Kim),류수정(Soojung Ryu),이혁재(Hyuk-Jae Lee) 대한전자공학회 2021 대한전자공학회 학술대회 Vol.2021 No.6

Due to the growing interest in accelerating deep learning training, vector processors are becoming an essential element in deep learning accelerators. In this paper, unlike previous studies focused on matrix multiplication accelerator, the effect of the register file size in the vector processor on the performance of the entire accelerator was investigated. Results show that the vector processor with 16-entry register file can achieve the best energy efficiency for given workloads, which is 45% smaller and 53% power efficient compared to the 32-entry register file baseline architecture with same performance.

Experimental Study of Injection-Compression Molding of Film Insert Molded Plates

Lee, Ho-Sang,Park, Jong-Rak 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.3

An injection-compression molding method was applied for film insert molding, where films had three-dimensional embossed patterns. An injection-compression mold was developed, and a one valve-gate hot runner system was built into the mold, in order to prevent melt backflow in the compression stage. Injection-compression molding experiments under different compression conditions, including compression stroke and compression speed, were performed, to investigate their effects on the height of embossed patterns. The compression stroke significantly affected the height of embossed patterns after film insert molding; however, the effect of compression speed on the embossed patterns was small. The main criterion for affecting the height of embossed patterns was not the maximum cavity pressure, but the integral value of cavity pressures along time. The degree of conservation of embossed patterns in injection-compression molding was significantly improved, and was more uniform along the positions, compared with that in conventional injection molding.

휴대폰 중간면의 인서트 사출성형공정에 관한 연구

민병현(Byeong-Hyeon Min),김병곤(Byeong-Gon Kim),예상돈(Sang-Don Ye) 한국산학기술학회 2022 한국산학기술학회논문지 Vol.23 No.4

휴대폰 외관의 미려함과 견고함을 확보하기 위해 고정밀 기능 부품들이 결합된 휴대폰 중간 면에 금속 부품과 플라스틱 수지를 결합한 인서트 사출 성형을 하였다. 휴대폰 중간면은 PBT(Polybutylene terephthalate) 보강재로 유리섬유 40% 함유 플라스틱 수지를 사용해 인서트 사출을 진행했다. USB 홀의 전체 길이는 성형품의 체적 수축으로 인한 치수 관리 위치로 사용되었다. 기존의 공정능력을 분석하여 USB 단자 전장 치수의 안정성 확보와 사이클 타임 축소를 통한 생산성 향상의 두 가지 목표를 연구 방향으로 설정하였다. USB 단자의 전장 치수의 관리 규격인 8.49±0.04 mm를 만족하면서 사이클 타임을 55초에서 33초로 22초 단축하는 사출성형공정조건을 최적화하였다. 양산 단계에서의 최적화 검증으로 장기공정능력지수 Zlt는 4.22σ, 단기공정능력지수 Zst는 4.89σ, Zshift는 0.67σ를 도출하였으며, 개선 전 공정능력과 비교하여 Zlt는 3.03σ 높아지고 Zshift는 0.57σ 낮아지는 등 기술력과 관리력에 대한 공정능력이 향상되었음을 확인하였다. The middle surface of a mobile phone, where high-precision functional parts are combined, is usually insert injection molding to achieve beauty and rigidity of the mobile phone"s exterior. In particular, injection molding can combine metal parts and plastic resin in the middle surface of a mobile phone effectively. This study insert injection molded the middle surface of a mobile phone from a plastic resin containing 40 % glass fiber as reinforcement in polybutylene terephthalate (PBT). The length of the USB hole was used as the measure in managing dimensional changes in the molded product due to its volumetric shrinkage. Next, two goals were set for further research after analyzing the existing process capability. These goals include securing the stability of the USB terminal"s overall dimensions and improving productivity by reducing cycle time. Subsequently, fixing the average target value for the length of the USB terminal to 8.49 mm minimized the average dimensional deviation. In addition, optimized insert injection molding conditions shortened the cycle time from 55 seconds to 33 seconds . The long-term process capability index Zlt was 4.22 σ, the short-term process capability index Zst was 4.89 σ, and the Zshift was 0.67σ for the optimized insert injection molding. Hence, the capability of the insert injection molding in terms of technology and management has improved with the proposed modifications.

Experimental Study of Injection-Compression Molding of Film Insert Molded Plates

이호상,박종락 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

An injection-compression molding method was applied for film insert molding, where films had three-dimensional embossed patterns. An injection-compression mold was developed, and a one valve-gate hot runner system was built into the mold, in order to prevent melt backflow in the compression stage. Injection-compression molding experiments under different compression conditions, including compression stroke and compression speed, were performed, to investigate their effects on the height of embossed patterns. The compression stroke significantly affected the height of embossed patterns after film insert molding; however, the effect of compression speed on the embossed patterns was small. The main criterion for affecting the height of embossed patterns was not the maximum cavity pressure, but the integral value of cavity pressures along time. The degree of conservation of embossed patterns in injection-compression molding was significantly improved, and was more uniform along the positions, compared with that in conventional injection molding.

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.

BLDC 모터 고정자의 인서트 사출 성형에 관한 연구

최두순(Choi, Du-Soon),김홍석(Kim, Hong-Seok) 한국산학기술학회 2015 한국산학기술학회논문지 Vol.16 No.9

인서트 사출 성형은 용융 플라스틱을 인서트가 삽입된 금형에 주입하는 공정이다. 사출 과정 중에 인서트는 용융 플라스틱이 가하는 압력에 의해 변형될 수 있다. 인서트의 변형은 인서트 주변의 유로 폭을 변화시키고, 이것은 미성형이나 성형품의 뒤틀림 같은 심각한 결함을 야기시킬 수 있다. 인서트의 변형을 감소시키기 위해서는 게이트 시스템, 인서트 형상, 성형 조건 등을 성공적으로 설계해야 한다. 본 연구에서는 BLDC 모터 고정자의 사출 성형 시 발행하는 인서트의 변형을 수치해석을 통하여 분석하였다. 인서트 변형을 감소시키기 위하여 게이트 위치와 인서트 형상을 수정하였다. 마지막으로, 수정된 설계로 사출 성형을 수행하고, 변형이 감소되었음을 확인하였다. Insert injection molding is a process in which molten plastic is injected into a mold that contains a pre-placed insert. During the injection stage, the insert can be deformed by the pressure applied by the polymer melts. The deformation of the insert changes the width of the flow path around the insert, which can cause several defects such as short shots or warpages of the parts. In order to reduce the deformation of the insert, it is important to achieve successful design of gating system, insert geometry, and molding conditions. In the present study, the insert deformations that occured during the injection molding of the BLDC motor stator were investigated by numerical analyses. The gate location and the insert shape were modified to reduce the insert deformation. Finally, the injection molding with the modified designs was carried out, and it was confirmed that the insert deformation was reduced.

인서트 사출 해석을 통한 자동차 도어용 커서부 개석

김동규 朝鮮大學校 機械技術硏究所 2005 機械技術硏究 Vol.8 No.2

Door cursor is the important part which is located between the window and guide-rail and has a function which transfers the power of the window motor to window. The door cursor is made by the insert injection molding technology which can be used for the part which has insert core in the plastic molding. Because the heat from the injection mold can influence the size of the insert core, the insert injection molding is the difficult work and the need of computer simulation is increased to reduce the trial and error of mold. To investigate the various factor of the injection mold, three kinds of design of mold are proposed. The short-shot, temperature distribution, distortion, pressure distribution, weld line for each design are discussed. As a result, the Case 2 and Case 3 were proved as the better designs compared to the original one.

Numerical Investigation of Warpage in Insert Injection- Molded Lightweight Hybrid Products

Trieu Khoa Nguyen,이봉기,황철진 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.2

In this study, a numerical investigation of warpage found within insert injection-molded frame parts was carried out based on the Taguchi method in conjunction with a response surface methodology. An integrated mold frame unit was recently developed by integrating a conventional mold frame, metal reflector, and bezel together, to be used in a back light unit system of a liquid crystal display. Such an integrated plastic-metal hybrid part could be successfully manufactured through the insert injection molding process. However, minimization or even elimination of warpage, one of the severe defects found in injection-molded products, is required for reliable mass production. Therefore, a numerical analysis was performed to reveal the effects of the relevant processing parameters, showing that packing pressure played the most significant role, originated from temperature difference between corners of the final product. Furthermore, a double optimization process combining the Taguchi method and the response surface methodology was employed to determine accurate and optimal processing conditions. The results clearly verified that the current combination technique can overcome the Taguchi method’s limitation, resulted from a discrete optimization nature, and also effectively give more accurate optimum solutions without complicated algorithms and software.

인서트 코어 타입 Cap 성형용 대용량 금형 제작에 관한 연구

정우철,허영무,신광호,윤길상,이정원,Jung, Woo-Chul,Heo, Young-Moo,Shin, Gwang-Ho,Yoon, Gil-Sang,Lee, Jeong-Won 한국금형공학회 2008 한국금형공학회지 Vol.2 No.3

In recent, the demands of household cases and disposable products is increased significantly because a living standard of newly-emerging nations was risen. Therefore, multi-cavity mold and stack mold for the realization of high-productivity have been researched in forefront nations. In this paper, CAE analysis for minimizing the mold core deformation was performed. Finally, 64 cavities injection mold for molding cap which has the insert-type core was fabricated according to the result of CAE analysis.