• 청정기술
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• 제30권2호
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• pp.94-104
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• 2024

재제조는 사용 후 제품을 분해, 세척, 검사, 보수, 조정, 재조립하여 원래의 성능 또는 그 이상의 성능을 가진 제품으로 재상품화하는 것으로, 재제조산업은 2050 탄소중립을 실현하기 위해 필요한 핵심 산업이다. 본 연구에서는 자동차부품 중 재제조가 활발히 이루어지고 있는 인젝터를 대상으로 전과정평가를 이용하여 회피효과를 고려 시와 미고려 시 자원 저감 및 온실가스 저감 효과를 분석하고자 한다. 연구결과, 인젝터 재제조로 인한 자원 저감 효과와 온실가스 저감 효과는 회피효과를 미고려 시 1개 기준으로 95.30%, 93.88%가 저감되는 것으로 나타났다. 재제조 시 제품을 재사용함으로써 사용 후 제품이 폐기되지 않는 환경영향과 천연자원을 사용하지 않는 환경영향의 회피효과를 고려할 시 190.91%, 188.33%가 저감되는 것으로 나타났다. 본 연구결과는 향후 재제조 시 회피효과를 고려한 환경영향 저감량을 평가하고, 연구방법론 개발 시 활용할 수 있을 것으로 본다.

• 청정기술
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• 제13권3호
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• pp.228-234
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• 2007

본 연구에서는 금형의 재활용을 촉진하기 위하여 성형공정을 소재의 제거공정과 부가공정으로 보고, 신속 성형 방법인 레이저 직접 금속조형(LADMD) 공정의 환경영향 및 생산성을 제거공정인 밀링가공과 비교하여 평가하였다. 두 가지 형상의 금형에 대하여 CAM 프로그램인 PowerMill을 이용하여 가공경로를 생성하고 가공시간을 예측하여 생산성을 알아본 결과 LADMD 공정의 생산성은 가공량이 유사한 경우에도 밀링공정에 비하여 월등히 우수한 결과를 보였다. 환경 친화적 가공방법으로 알려져 있는 LADMD 공정을 에너지의 사용에 초점을 맞추어 평가한 결과로는 레이저의 발생을 위하여 사용하는 전기에너지의 양이 전통적인 밀링가공법에 비하여 월등하게 많은 점이 앞으로 개선하여야 할 문제임을 알 수 있었다. 여러 가지 장점을 갖고 있는 LADMD 공정은 생산성 및 경제성이 우수하고 자원의 낭비를 줄일 수 있으며 친환경적인 가공법으로 재제조 분야에서 유용하게 사용될 수 있을 것이다.

• 한국산업융합학회 논문집
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• 제23권3호
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• pp.381-392
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• 2020

The necessity and the importance of the remanufacturing are increasing day by day along with environmental problems. Many studies are being conducted on remanufacturing, but the research for cleaning is much lacking. This study aims to evaluate the effective cleaning method for remanufacturing of start motors, one of the automobile parts. The cleaning process consists of oil stain removal, drying and rust removal processes. In this study, the two processes were conducted except for the drying process which has little influence on cleaning. The methodology for cleaning agent selection, degreasing and rust removal process was presented. For each methodology, five analysis factors were calculated by two-way comparison according to the process, and the values were evaluated quantitatively by substituting them into the evaluation table. In the selection of cleaning agent, neutral system, ultrasonic cleaning in degreasing, and grinding in rust removal were selected as the best cleaning methods.

• 공업화학
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• 제20권4호
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• pp.430-436
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• 2009

가솔린 자동차 배출가스에 장기간 노출되어 활성이 저하된 폐 삼원촉매를 대상으로 재제조를 수행하였다. 재제조된 삼원촉매, 자동차 배출가스에 노출되지 않은 신촉매와 폐 삼원촉매에 대해 촉매의 물성분석과 CO, THC 및 NOx에 대한 전환활성을 측정하여 비교 분석하였다. 폐 삼원촉매의 재제조는 증류수 및 산성용액을 이용하여 초음파 세정하는 것과 세정된 촉매에 촉매의 활성성분인 Pt, Pd 및 Rh를 재함침하는 방법으로 수행하였다. 폐 삼원촉매를 재제조하는 과정에서 촉매표면에 축적되었던 각종 불순성분들이 대부분 제거 되었으나 촉매활성 성분인 Pt나 Pd 또한 함께 제거되는 것으로 판단되었다. 촉매활성 성분을 함침하여 폐 삼원촉매를 재제조 할 경우 재제조된 촉매의 활성은 신촉매의 활성보다 같거나 우수한 것으로 나타났다.

• Corrosion Science and Technology
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• 제6권5호
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• pp.257-260
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• 2007

In order to further improve the corrosion resistance and wear resistance of the Ni-P coatings of electroless plating, electroless Ni-P/n-$Al_2O_3$ composite deposits were prepared by adding some nano $Al_2O_3$ Particles in Ni-P plating bath. The bath composition and proproties were studied in this paper. The orthogonal test was applied in order to get the new composite solution, taking the initial stable potential as evaluation standard and considering the elements correlation at the same time. The processing parameters have been optimized by single factor experiment in which the depositing speed was chosen as the evaluation standard. The results showed that the process is stable and the composite Ni-P/n-$Al_2O_3$ deposits werebright and smooth, whose hardness and corrosion resistance are much better than simple Ni-P coatings. Furthermore the surface appearance and structure of the composite Ni-P/n-$Al_2O_3$ coating were investigated by SEM and XRD method. It was proved that the coating surface is typical cystiform cells and its structure is amorphous. All test results ofcomposite coating showed that all various physical coating properties had been improved by adding nano-particles. The hardness of optimal coating is more than 600HV and increases to 1000HV after heat-treating, and its hardness is 20~50% higher than Ni-P coating. The rust points appeared in 200 hour by immersing the coating into the 10%HCl solution and the corrosive speed is $3{\times}10^{-3}mg/(cm^2{\cdot}h)$which was obtained after 300 hour. In the same condition Ni-P coating is $5.6{\times}10^{-3}mg/(cm^2{\cdot}h)$. The salt spray resistance of the layers can exceed 600h with the thickness $20{\mu}m$.

• 한국산업융합학회 논문집
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• 제26권1호
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• pp.95-103
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• 2023

The domestic remanufacturing industry is concentrated in auto parts, so it is necessary to expand into various industries. In the domestic aluminum industry, the extrusion process accounts for more than 40% of the total, but the old and management of the extrusion equipment is not done properly. In particular, the extruder has a structure in which equipment is not replaced until major parts are damaged or worn, so there are problems such as lower process precision, productivity and production efficiency compared to new equipment, and high maintenance costs. In this study, the old extruder was remanufactured for major high-risk parts through Failure Mode and Effect Analysis(FMEA), and the process level and performance of the extruder were evaluated before and after remanufacturing. Compared to the existing extruder, the standard deviation of the remanufacture extruder was reduced by 93.5%, 57.9%, and 70.0%, respectively, in major process control items such as container temperature, billet temperature, and ram speed, keeping performance constant. In addition, it was possible to produce products with complex shapes that could not be produced before due to problems such as dimensional deviation within tolerances. In this study, remanufacturing guidelines were presented by analyzing the effect of failure modes of the old extruder, and the performance improvement of the extruder was confirmed.

• 한국산업융합학회 논문집
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• 제26권6_2호
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• pp.1055-1062
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• 2023

Globally, the need for remanufacturing or reusing ships and various mechanical parts continues to increase due to environmental problems including global warming. Research on remanufacturing is being carried out in many areas. However, research on inspection and classification to identify the performance or degree of wear of mechanical parts is insufficient. In particular, studies on the inspection-ability and classification-ability of mechanical parts equipped with various materials and complex forms are highly required. Remanufacturing must be considered from the stage of design to extend the life cycle of mechanical parts. Particularly, it is very important to perform research for evaluating the degree of ease to inspect and classify various sorts of wear or deterioration of parts caused by long-term use easily. In this study, the degree of ease in inspecting or classifying mechanical parts for remanufacturing is defined as inspection-ability and classification-ability. In fact, to remanufacture old parts, inspection-ability and classification-ability should be reflected from the stage of design. The purpose of this study is to evaluate the inspection-ability and classification-ability of ships and various mechanical parts. This researcher has presented the quantitative evaluation procedure of inspection-ability and classification-ability, derived the factors and ranges that influence each of the details of easiness, assigned scores according to the ranges of the factors, and calculated weights. Lastly, this study presents the procedure of scoring to evaluate the overall weights of inspection-ability and classification-ability and also inspection-ability and classification-ability quantitatively.

• 청정기술
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• 제13권2호
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• pp.134-142
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• 2007

본 연구에서는 재제조를 용이하게 하기 위하여 분해용이성 및 분해시간 산출이라는 두 가지 방법을 이용하여 부품의 분해성 평가 방법을 제시하였다. 또한 부품별 평가로부터 얻어진 분해성 지수로부터 최소 부품수의 개념을 이용하여 제품의 분해성을 도출하는 방법을 개발하였다. 제시된 방법들을 컴퓨터의 외장 케이스에 적용하여 비교 분석하였다. 분해용이성 및 분해시간의 분석에 의한 분해성 평가는 케이스의 일부 분리를 용이하게 한 새 모델이 재제조를 위한 전체 분해시에는 오히려 분해성이 악화된다는 동일한 결론을 보여주었다. 이러한 분해성 평가 방법은 제품의 재제조 및 재활용 특성을 평가하는데 중요한 지표중의 하나로 사용될 수 있을 것이다.

• Management Science and Financial Engineering
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• 제18권1호
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• pp.1-12
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• 2012

In this paper, we report a case study on the common due-date assignment and scheduling problem in a paper remanufacturing system that produces corrugated cardboards using collected waste papers for a given set of orders under the make-to-order (MTO) environment. Since the system produces corrugated cardboards in an integrated process and has sequence-dependent setups, the problem considered here can be regarded as common due-date assignment and sequencing on a single machine with sequence-dependent setup times. The objective is to minimize the sum of the penalties associated with due-date assignment, earliness, and tardiness. In the study, the earliness and tardiness penalties were obtained from inventory holding and backorder costs, respectively. To solve the problem, we adopted two types of algorithms: (a) branch and bound algorithm that gives the optimal solutions; and (b) heuristic algorithms. Computational experiments were done on the data generated from the case and the results show that both types of algorithms work well for the case data. In particular, the branch and bound algorithm gave the optimal solutions quickly. However, it is recommended to use the heuristic algorithms for large-sized instances, especially when the solution time is very critical.

• 한국기계가공학회지
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• 제21권3호
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• pp.36-42
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• 2022

Whereas the necessity for recycling and reuse is being emphasized owing to the depletion of resources and waste disposal problems caused by the continuous development of the industry, the importance of remanufacturing has been highlighted recently. Re-manufacturing involves a series of processes in which failed disposal or aging goods are recovered to a state similar to that of a new product. In this regard, machine tools, which are large structures, can achieve the effect of remanufacturing. Among the various elements constituting the machine tool, the main spindle portion that affects the processing precision is critical. Therefore, this study is conducted to derive improvement measures for the main axis of an old Miller planner via reverse engineering and central composite design, which is one of the core processes of remanufacturing.