• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.6
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• pp.110-116
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• 1994

In this research, the tensile strength of molded parts and pressure distribution were analyzed to study the cavity filling stage and packing stage in injection molding. The measurement of cavity pressure was obtained by a data acquisition system with the installation of transducers in the cavity. Molded parts were tested by a universal testing machine to obtain the tensile strength. For the experimental work, the tensile strength of molded parts increased with longer packing time and exact freezing time of the gate was obtained by a cavity pressure curve. In addition, the effect of packing did not occur and tensile strength was almost constant after early 1.5 sec of the freezing time of gate. Density tended to be higher about 0.2% due to a larger degree of mold temperature and melt temperature. Also, changing pressure in the cavity was effectively sensed. Thereafter, the possibility of the development of pattern recognition expert system was confirmed on the basis of the experimental results.

• Design & Manufacturing
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• v.14 no.4
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• pp.25-39
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• 2020

In this study, an edge device that monitors the injection molding process by measuring the mold vibration(acceleration) signal and the mold surface temperature was developed and evaluated its performance. During injection molding, signals of the injection start, V/P switchover, and packing end sections were obtained through the measurement of the mold vibration and the injection time and packing time were calculated by using the difference between the times of the sections. Then, the mold closed and mold open signals were obtained using a magnetic hall sensor, and cycle time was calculated by using the time difference between the mold closed time each process. As a result of evaluating the performance by comparing the process data monitored by the edge device with the shot data recorded on the injection molding machine, the cycle time, injection time, and packing time showed very small error of 0.70±0.38%, 1.40±1.17%, and 0.69±0.82%, respectively, and the values close to the actual were monitored and the accuracy and reliability of the edge device were confirmed. In addition, it was confirmed that the mold surface temperature measured by the edge device was similar to the actual mold surface temperature.

• Food Science and Preservation
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• v.3 no.1
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• pp.77-82
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• 1996

Most of countries differ from their favors, in Taiwan fruit juice and sweet taste are emphasized while external appearance in Japan. During transportation, movement of the container, fluctuation of temperature, decrease of the fruit freshness and undesirable packing materials tend to decline fruit marketability. For these problems, it is believed that shortening of boarding time by utilization of plate and styro form box for packing, the author believed.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.363-369
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• 2006

Effects of three packing materials and exposure time on the mortality of Plodia interpunctella and Tribolium castaneum were studied using $CO_{2}-modified$ atmosphere control. Materials used were triple layered craft paper (KKK), triple layered craft paper with one laminate coating layer (KLK), and triple layered craft paper with one HD film coating layer (KHK). In the test balls (${\phi}1.2\;m$) containing 85% $CO_{2}-modified$ atmosphere, concentration of $CO_{2}$ in small packing envelopes ($9.8{\times}9.8cm$) made of the materials after one day was higher in KKK ($26.67{\pm}0.58%$) than KLK ($23.33{\pm}0.58%$) or KHK ($20.67{\pm}0.58%$). Both P. interpunctella and T. castaneum showed higher mortality in KKK than in either KLK or KHK Similar results were obtained by larger space ($9{\times}4{\times}3m$) and packing volume (20 kg) studies. The effect of the packing materials was clearer on T. castaneum more tolerant to $CO_{2}$ than P. interpunctella. Regression of the insect mortality on cumulative concentration time (${\int}_{0}^{t}c{\times}tdc{\approx}{\sum}concentration{\times}time$) was highly significant. Control of P. interpunctella and T. castaneum by $CO_{2}-modified$ atmosphere were discussed in relation to packing materials, cumulative concentration time of $CO_{2}$ and food products.

• 한국금형공학회:학술대회논문집
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• 2008.06a
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• pp.163-166
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• 2008

Injection molding operation consists of filling, packing, and cooling phase. The highest pressure is involved during the packing phase among the operation phases. Cavity pressure depends upon velocity to pressure switchover time and magnitude of packing pressure. The cavity pressure is directly related to stress concentration in the cavity of mold. Thus the observation and control of cavity pressure is very important to prevent mold cracking. In this study, cavity pressures were observed for operational conditions using the commercial CAE software,Moldflow. Operational conditions were velocity to pressure switchover time and packing pressure. Cavity pressures were also measured directly during injection molding. Simulation and experimental results showed good agreement.

• Design & Manufacturing
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• v.2 no.5
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• pp.30-33
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• 2008

Injection Molding is the most effective process for mass production of plastic parts. The injection molding process is composed with several steps such as Filling, Packing, Holding, Cooling, Ejecting. Among them, filling and packing process should be considered carefully to improve accuracy of dimension, surface quality of plastic parts. Usually the quality above-mentioned is managed with weight of part after molding on the field. In this paper, a series of experiment for molding automotive front bumper was conducted with cavitity temperature sensor to optimize switch-over time(V-P switching), hot runner vale gate sequence time during filling and packing step for the purpose of uniform quality, weight at every molding. As a result, it was found that it is effective method to use temperature sensor in injection molding for quality control of plastic molding.

• Journal of environmental and Sanitary engineering
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• v.18 no.1
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• pp.15-22
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• 2003

Treatability tests were conducted using EMC process to study the feasibility of applying this process as recycling-water treatment system in high density seawater aquaculture farm. To study the effect of organic and ammonia nitrogen loading on system performance, hydraulic retention time of reactor was reduced gradually from 12hr to 10min. The conclusions are can be summarized as follows. When the system HRT was reduced from 12hr to 10 min gradually, there was little noticeable change(reduction) in ammonia nitrogen removal efficiencies until 2hr of HRT, however, removal efficiencies were decreased dramatically when the system was operated under the HRT of less than 2hr. In case of organics(COD), there was no dramatic deterioration in removal efficiencies depending on HRT reduction. More than 90% of removal efficiencies were maintained successfully when the system was operated at the HRT of 10 min. In case of system performance depending on media packing ratio in reactor, there was little difference in each reactor performance depending on media packing ratio in reactor when the reactors were operated under the HRT of longer than 1hr, however, differences in reactor performances were considerably evident when the reactors were operated under the HRT of shorter than 1hr. That is, the more reactor was packed, the better reactor performed. When comparing reactor performance among 25%, 50%, 75% packed reactor, it can be judged that media packing ratio more than 50% plays no significant role in increasing reactor performance. For this reason, packing the media less than 50% is more reasonable way in view of economic. Such a tendency well agreed with the variation of ammonia-nitrogen removal efficiencies according to the media packing ratio in reactors at each HRT. Difference in effluent ammonia-nitrogen concentration between 50% media packing reactor and 75% media packing reactor was negligible. When comparing with the results of 25% packing reactor, difference was not so great.

• Journal of Environmental Science International
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• v.9 no.5
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• pp.393-396
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• 2000

Packing tower has been used in the chemical industry and the protection of environment for a long time. In the view of environmental protection purification of exhaust gas can be performance effective by gas absorption in counter-current packing tower. In this study characteristics of hydraulic and mass transfer were investigated in D. $0.3m {\times} H. 1.4m$ packing tower with 50mn plastic Hiflow-ring. This study was carried out "Test systems were experimented in conditions of Air, $Air/H_2O. NH_3-Air/H_2O, NH_3-Air/H_2O-H_2SO_4$ and $SO_2-Air/H_2O-NaOH$ under steady state" The extent of test included dry and wetting pressure drop physical law separation efficiency and hold-up as function of gas and liquid load.quid load.

• Korean Management Science Review
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• v.22 no.1
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• pp.167-178
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• 2005

The 2DBPP(Two-Dimensional Bin Packing Problem) is a problem of packing each item into a bin so that no two items overlap and the number of required bins is minimized under the set of rectangular items which may not be rotated and an unlimited number of identical .rectangular bins. The 2DBPP is strongly NP-hard and finds many practical applications in industry. In this paper we discuss a tabu search approach which includes tabu list, intensifying and diversification Strategies. The HNFDH(Hybrid Next Fit Decreasing Height) algorithm is used as an internal algorithm. We find that use of the proper parameter and function such as maximum number of tabu list and space utilization function yields a good solution in a reduced time. We present a tabu search algorithm and its performance through extensive computational experiments.

• Journal of Biosystems Engineering
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• v.27 no.5
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• pp.399-408
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• 2002

The sweet persimmons are producted 227,394 tons per year in Korea. They are preserved at cold storage after wrapping them in packing vinyl to maintain quality. Using conventional handwork, a skillful worker could probably produce only 1,000 packings a day. Hiring many skilled-labors to wrap sweet persimmons in packing vinyl seems to be difficult because of the recent rural crisis. Therefore, it was necessary to be developed for the automated ordering and packing unit that is convenient and laborsaving. This study were summarized as follows : Success rates of 99%, 100%, and 88% were observed for ordering parts, sealing and cutting films, and sealing films in the inlet part, respectively. The time required per 1 cycle was 16 seconds and the developed unit performed 225 cycles an hour. The unit showed an ability of 1,125 pieces per hour. Therefore, the productivity was 10 times greater than that of skillful handwork.