• 한국산업보건학회지
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• 제33권4호
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• pp.517-527
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• 2023

Objectives: We examine cases of chemical poisoning that occurred in the cleaning of metal parts and the regulations on halogenated solvents in other countries and propose regulations necessary to prevent chemical poisoning from halogenated solvents. Methods: We collected cases of chemical poisoning through the website of the Korea Occupational Safety and Health Agency. A review of the literature was conducted focusing on regulations related to halogenated solvents in the United States and the European Union, particularly for cleaning metal parts. Among the Material Safety Data Sheets submitted to the government, MSDS containing eleven substances were extracted to confirm the composition and product use. We investigated cleaning methods for metal parts used in South Korea. For the hazard classification, the European Chemicals Agency or Japan's NITE's website was used. Results: In the case of poisoning, the cleaning methods involving trichloromethane were dipping and dry, which was not found in the literature. It was confirmed that many halogenated solvents and dimethyl carbonate were used for metal cleaning in South Korea. In vapor degreasing using TCE in the USA, even if the facility is strictly managed, such as by installing cooling coils in open cleaning facilities, the risk of exposure to TCE is considered to be not only carcinogenic but also a concern for acute and chronic effects. In comparison, exposure through Korean work methods such as dipping and drying operations is inevitably much higher. Conclusions: The transition to water-based cleaning with low-hazard chemicals should be a priority in the cleaning process. In the case of metal parts that require precise cleaning, if the use of a halogenated solvent is inevitable, a closed degreasing facility should be used to minimize exposure. The current regulations in the Occupational Safety and Health Act, the Chemical Substances Control Act, and the Air Environment Conservation Act do not require cleaning facilities to minimize emissions. To protect the health of workers using halogenated solvents to clean metal parts, regulations that require a fundamental reduction in exposure will be necessary.

• Journal of Welding and Joining
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• 제7권2호
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• pp.60-69
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• 1989

The present study was aimed at investigating the effect of welding parameters such as welding current, electrode force(or squeeze force) and parts cleaning on the sound weld, and establishing the most reliable weld conditions for HWP(Heavy Water Reactor) fuel end capping with the resistance upset butt welding. Major results obtained are as follows. 1. The amount of sound weld was increased with increasing weld current(5.0-11KA) because the activated diffusion with increasing heat generation played an important role in eliminating the porosity and weld line in the weld interface. 2. It was found that weld current was not significantly influenced by the electrode force although the increase of it caused a slight increase of weld current and upset deformation. 3. Acetone rinsing before drying for the Zircaloy-4 end cap cleaning produced the reliable sound weld because it would remove the remaining solvent and surface films, and provided the uniform contact between the end cap and the tube. 4. The optimum welding conditions for fuel end capping by a resistance upset hytt welding are obtained as follows. weld current: 10-11KA, electrode force: 62-90KPa parts cleaning: vapor degreasing.rarw.water, acetone rinsing.rarw.drying.

• 청정기술
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• 제12권4호
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• pp.250-258
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• 2006

CFC-113과 1,1,1-trichloroethane 등과 같은 CFC 화합물은 화학적 안정성 및 열역학적 특성 등이 우수하고, 불연성이며, 부식성이 없는 화합물로 오랜 시간 동안 전 산업에 걸쳐 널리 사용 되어 왔다. 하지만, 1989년 지구 환경의 보호를 위해 이들의 생산과 사용을 규제하는 국제협약인 '오존층 파괴물질에 관한 몬트리올 의정서'가 체결되어 대체 세정제가 요구되고 있다. 본 연구에서는 세정 시스템을 변화시키지 않고 세정력이 우수하면서 환경 친화적이며 인체 유해도가 낮으며 부식성 물질을 발생 시키지 않는 비수계 세정제를 개발하고자 하였다. 이를 위하여 글리콜 에테르계의 용매와 파라핀계 탄화수소 물질을 일정 비율로 혼합, 배합하면서 실록산을 첨가하여 비수계 세정제를 배합 제조하였다. 그리고 이들 세정제의 물성과 세정성을 평가하여 대체 세정제로서의 가능성을 평가하였다. 배합세정제의 물성측정 결과 밀도와 표면장력이 낮아 오염물에 대한 침투력이 우수할 것으로 예상되었고 인화점과 증기압 측정값으로 세정제의 안전성을 평가할 수 있었다. 플럭스, 솔더 및 그리스에 대한 세정성능 측정결과 높은 세정성능을 보여주었고 피세정물의 표면에 잔류물이 생성되지 않았다. 결과적으로, 규제물질과 동등한 세정능력을 지니며 침투력이 우수하고 인체 유해도가 낮은 세정제를 개발할 수 있었다.