• Elastomers and Composites
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• 제52권4호
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• pp.317-325
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• 2017

Molding conditions can be described as factors that determine the quality of a product obtained from injection molding. Many studies have been performed on the injection molding pressure, injection temperature, packing pressure and other molding conditions related to part quality. However, the most accessible factor among the adjustable molding conditions during actual injection is the injection speed. In this study, we simulated the variation of the physical quantity according to injection speed and performed experiments to understand the effect of injection speed on the actual product. A CAE analysis program (Moldflow) was used to simulate and analyze the results using PC and PBT for two models. In order to compare these results with the experimental results, an actual injection molding was performed for each injection speed, and the correlation between simulation and injection molding, especially for the shrinkage of the molded article, was discussed.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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• pp.83-86
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• 2001

In injection molding, short shot is one of the frequent and fatal defects. Experts of injection molding usually adjust process conditions such as injection time, mold temperature, and melt temperature because it is the most economic way in time and cost. However it is a difficult task to find appropriate process conditions for troubleshooting of short shot as injection molding process is a highly nonlinear system and process conditions are coupled. In this paper, a fuzzy neural network(FNN) has been applied to injection molding process to shorten troubleshooting time of short shot. Based on melt temperature and fill time, a reasonable initial mold temperature is recommended by the FNN, and then the mold temperature is inputted to injection molding process. Depending on injection molding result, specifically the insufficient quantity of an injection molded part, an appropriate mold temperature is recommend repeatedly through the FNN.

• 한국자동차공학회논문집
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• 제4권6호
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• pp.144-152
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• 1996

In the sequential MPI system with one injection for each cycle, engine performance is influenced by the mixture conditions. It can be said that engine performance is improved by being better identical mixture formation conditions for all cylinders. As the fuel injection timing to the intake port effects on the mixture formation conditions and the engine performance, injection timing must be better adjusted to engine requirements. Engine behavior was clearly different depending on the injection time during intake storke. Therefore it was studied that injection timing of fuel effects on the engine performance I. e. combustion stability, COV(imep), A/F excursion, CO,HC emission concentration and fuel consumption. It was found that late intake-synchronous injection was deteriorated the combustion characteristics and performance characteristics, while early intake-synchronous infection resulted in favorable engine behavior.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.3044-3048
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• 2008

It is well known that Premixed Charge Compression Ignition (PCCI) diesel engines according to many technologies such a change in injection timing, multiple injection strategy, cooled EGR, intake charging and SCV have the potential to achieve homogeneous mixture in the cylinder which result in lower NOx and PM as well as performance improvements. This may generate merely the infinite number of experimental conditions. The use of Response Surface Methodology (RSM) technique can considerably pull down the number of experimental set and time demand. This paper presents the effects of both fuel injection and engine operation conditions on the combustion and emissions in the PCCI diesel engine system. The experimental results have revealed that a change in fuel injection timing and multiple injection strategy along with various operating conditions affect the combustion, emissions and BSFC characteristics in the PCCI engine.

• Design & Manufacturing
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• 제8권2호
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• pp.12-17
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• 2014

Currently, injection molding process is a very useful technique that be applied to many field. And injection molding technology has been commercial based on many studies. However, there is no standard of surface roughness because there are few studies about surface technology of injection product. In addition, when designing the mold, changes of the core surface and the injection conditions are not considered. In this paper, change of surface according to the core and the injection conditions was compared with the surface of the injection product. Accumulation of these technologies will propose direction in mold design, manufacturing and injection molding technology.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.311-312
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• 2012

Homogeneous charge compression ignition combustion with multiple-injection strategy using dimethyl-ether was investigated in a single cylinder direct-injection compression-ignition engine. The combustion performance and exhaust emissions were tested by varying the post injection conditions. The experiments were carried out under low load and low speed conditions. By the late post injection near the top dead center, the combustion phase was retarded and lengthened, and the fuel conversion efficiencies improved without the drawbacks of exhaust emissions increment.

• 한국분무공학회지
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• 제13권1호
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• pp.1-8
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• 2008

It was investigated how fuel injection timing - early injection and later injection - in conjunction with throttle open rate effect the fuel-air mixing characteristics, Engine power, combustion stability and emission characteristics on a DI CNG spark Engine and control system that had been modified and designed according to the author's original idea. It was verified that the combustion characteristics were changed according to fuel injection timings and Engine conditions determined by different throttle open rates and rpm. It was found that the combustion characteristics greatly improved at the complete open throttle rate with an early injection timing and at the part throttle rate with a late injection timing. Combustion duration was governed by flame propagation duration in a late injection timing and by an early flame development duration in an early injection timing. As the result, we discovered that combustion duration is shortened, lean limit is improved, air-fuel mixing conditions controlled, and emissions reduced through control of fuel injection timing according to change of the throttle open rate.

• 한국기계가공학회지
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• 제5권4호
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• pp.46-52
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• 2006

From the past, most of the studies about thermoplastic elastomers(TPEs) have been conducted for theirs compounded materials and morphology. However these studies do not directly affect on injection molding processing. Therefor this study is focus on the variation of mechanical properties on TPEs moldings by increasing injection molding conditions which included injection molding conditions include injection pressure, holding pressure, melt temperature, mold temperature. The used experimental TPEs is a group of styrene(TPS). Injection pressure slightly affected on tensile strength, shrinkage and hardness. Holding pressure only affected on hardness. The melt temperature was the most affective condition on tensile strength.

• Design & Manufacturing
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• 제9권1호
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• pp.14-17
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• 2015

In the data from synthetic resin makers, there is no shrinkage deviation through injection molding. But, after making the required products, even in the same conditions, there are some size-deviation in colors. Into our research, we checked main factor by the injection molding conditions. Our tests have shown this results, there are some shrinkage deviation in collors and, in the injection molding conditions, packing pressure is the main factor.

• 한국산학기술학회논문지
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• 제9권1호
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• pp.165-169
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• 2008

사출 조건이 이성분계 고분자 블렌드의 형태학에 미치는 영향을 관찰하기 위해 폴리페닐렌옥사이드 (PPO)/폴리아마이드 6 (PA 6) 블렌드를 선정하였다. 두께가 3.2 mm이고 한 변의 길이가 15 cm인 정사각형의 평판 형태의 사출물을 여러 사출 조건에서 제조하고 각 위치별로 파단시편을 제조하여 형태학을 관찰하였다. 그 결과 수지가 스크류, 노즐 스프루 게이트를 지나 최종위치에 자리 잡을 때까지 복잡한 온도, 전단력과 신장력의 영향으로 복잡한 형태학을 가짐을 알 수 있었다.