• Journal of Preventive Medicine and Public Health
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• v.30 no.2 s.57
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• pp.381-391
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• 1997

In an epidemiological study of metal workers exposed to metalworking fluids (MWF), the prevalence time of Evolution, seasonal occurrence and clinical type of contact dermatitis were investigated. Compostional analysis of MWF with HPLC, dermatological examination and two consecutive questionnaire surveys were conducted. Study population was divided into two groups ; workers contact to cutting oil and workers contact to rust preventive oil. In the analysis of MWF, aliphatic hydrocarbons, having 12-20 carbons, was most common composition(49.04%) of cutting oil otherwise, major contents (90.99%) of the rust preventives oil were aliphatic hydrocarbons composed of 6-9 carbons. The frequency (point prevalence) of contact dermatitis(CD) was 7(12.7 per 100 subjects) in the dermatological examination of 55 workers. As the result of second survey for contact dermatitis, cumulative prevalence of oil working full-time and recent 1 year prevalence in two groups were 28.0, 16.7 and 15.1, 12.5 per 100 subjects. There were no difference in the prevalence of CD by oil, age, oil contact duration. Summer is the most common evolution season in workers exposed to cutting oil, but not in workers exposed to rust preventive oil. Major clinical type of CD was erythematous papules in both groups. It presents the importance of preventive measures that 51.1% suffer from contact dermatitis had medical care at their own expense, and 47.1% of them felt serious about their contact dermatitis. From the fact that 68.6% think cotton gloves protective apparatus, we emphasize the need for health education.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.531-532
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• 2003

공작기계 가동시 윤활과 냉각 등의 목적으로 다양한 종류의 금속가공유 (MWFs : 절삭유, 윤활유, 방청유 둥)를 사용하고 있다. MWFs에는 포름알데히드, 니트로스아민, 염화파라핀 등의 발암물질이 포함되어 있는 것으로 알려져 있어 작업자 건강보호를 위해 효율적인 환기가 요구되고 있다. 현장에서 가장 많이 사용하고 있는 포켓 필터형 오일미스트 콜렉터는 제진 장치가 없기 때문에 필터 표면에 한번 부착된 오일 미스트와 먼지가 떨어지지 않기 때문에 일정시간 후 필터 표면에 막힘 현상이 발생한다. 필터 표면이 막히면 차압 증가와 함께 송풍량이 감소하기 때문에 미스트 제거 효율이 크게 저하되고, 결과적으로 오일미스트의 환기 효율이 크게 감소된다.(중략)

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.50-62
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• 2003

Exposure to metalworking fluids (MWFs) has significantly been associated with cancer developed in multi-organs, respiratory diseases and skin diseases. Several carcinogens to humans or animals are contained in MWFs. They have been reported to be mineral oils, polynuclear aromatic hydrocarbons (PAHs), formaldehyde and N-nitrosodiethanolamine (NDELA). The great hazards of MWF have forced the advanced country including United States to regulate carcinogens contained in MWF. In 2001, American Conference of Governmental Industrial Hygienists (ACGIHs) regarded MWF mist as suspected carcinogen to human (A2) and added it to “Notice of Intended Change (NIC)” list of 2001. In spite of the fact that much MWF has widely been used in many industries using machines, Korea has no legal actions for management of MWF. What is worse, even toxicity such as Carcinogenicity has not been reported. KS (Korean Standards) lists 7 advices of MWF but it does net state the hazards to health. It is very hard to control or minimize worker's exposure to MWF containing many carcinogens. Prier to the introduction of MWF to workplace, it is the most effective measure to regulate carcinogens below a certain level. Regulation on the content of PAH seems to be necessary because less amount of PAH in mineral oils improves the quality of MWF. Also, addition of nitrosating groups to MWF should be prohibited to minimize worker's exposure to NDELA. Employers and manufacturers should indicate the Carcinogenicity of all carcinogens in MWFs in Material Safety Data Sheets (MSDS) in order fer workers to recognize Carcinogenicity. Legal actions have to be taken to protect workers from health hazards due to exposure to MWF by further investigation on MWF.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.1033-1036
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• 2001

The object of this paper is to find out a coolant level, which is economic and similar to the conventional level, high level, in cutting temperature. For this, new coolant level, called a low level, was proposed, which is about 1/4 of conventional level. And the cutting temperature of each coolant level in turning was analyzed using statistical method. Firstly, it was analyzed that the temperature mean of each coolant level is not equal by ANOVA-test. Secondly by Tukey's HSD, one of multiple comparisons, it was analyzed that the temperature mean of low level is similar to that of high level and different from that of none level.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.881-884
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• 2003

Owing to governmental regulations and concern regarding the safety of the environment, environmental conscious machining technology has become important in today's manufacturing industries. However, cutting conditions in metal cutting processes must also consider traditional dimensions such as production cost, production time and quality of a final product. The purpose of this study is to determine the cutting conditions in achieving a balanced consideration of productivity and environmental consciousness. The environmental factors such as cutting fluid, toxicity and energy are considered in metal cutting processes. In order to consider the relationship between environmental impacts and machining parameter, two factors of the metal cutting processes in this study are considered: cutting fluid and tool life. The experimental results are provided and discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.20-25
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• 1996

The needs to machine hardened steels with high productivity and good surface integrity have been increased in the dies ＆ molds industry. This paper presents some experimental results on the CBN ball endmilling for hardened tool steel. This investigation concerns on the effects of cutting speed and cutting fluids on the cutting performance such as cutting forces, tool wear, and surface finish. The wear of CBN ball endmill for each cutting conditions were also examined through the microscopic observation. It has been found out that the higher cutting speeds with cutting fluids result in better cutting performance.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.10
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• pp.157-163
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• 1997

The needs to machine hardened steels with high productivity and good sufrace integrity have been increased in the dies & molds industry. This paper presents some experimental results on the CBN ball endmilling for hardened tool steel. This investigation concerns on the effects of cutting fluids, cutting speed, and feed on the cutting performance such as cutting forces, tool wear, and surface finish. The wear of CBN ball endmill for each cutting conditions were also examined through the microscopic observation. It has been found that the higher cutting speeds with cutting fluids result in better cutting performance.

• Membrane Journal
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• v.25 no.4
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• pp.320-326
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• 2015

In this study, permeation experiments were carried out using the symmetric and asymmetric sinusoidal flux continuous operation (SFCO) modes for the submerged flat sheet membrane in the 0.5 wt% emulsion type cutting oil solution. The effective area and nominal pore size of the used microfiltration membrane were $0.02m^2$ and $0.15{\mu}m$, respectively. The emulsion cutting oil was rejected over 99% based on turbidity. Transmembrane pressure increased lower as the aeration rates increased. The symmetric SFCO mode was a little more effective than the symmetric SFCO mode in low permeate flux between 10 and $15L/m^2{\cdot}h$. However, the symmetric SFCO mode was shown very effectively in high permeate flux between 25 and $30L/m^2{\cdot}h$.

• Clean Technology
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• v.8 no.3
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• pp.119-128
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• 2002

In the present study the membrane filtration characteristics of a commercially available synthetic water-based cutting oil through two kinds of ultrafiltration membranes (HF1-45-CM50 and HF1-43-CM100) with molecular weight cut-offs of 50,000 and 100,000, respectively, have been investigated in detail. Among these membranes, the hydrophilic one (HF1-45-CM50) was found to show a satisfactory result for both the permeate flux and the permeability of oil components, whereas the permeate flux obtained with the hydrophobic membrane (HF1-43-CM100) appears to be significantly low, indicating that synthetic cutting oil was easily wetted on the hydrophobic membrane surface and induced more membrane fouling. The effect of material characteristics of the membrane on the filtration characteristics was found to be much more significant compared with the mean pore size of the membrane. Backflushing by nitrogen gas was applied to reduce the formation of a gel layer and membrane fouling. With the hydrophilic membrane, the backflushing was found to increase the permeate flux, whereas the backflushing resulted in a decrease in flux for the hydrophobic membrane. The flux recovery was observed to be highest when the membranes fouled with waste synthetic cutting oil were immersed into a cleaning solution for more than 72 hours and then backflushed by nitrogen gas.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.972-975
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• 2000

Environmental factors have become important in manufacturing planning due to governmental regulations and a growing preference for "green" products. However, planning decisions must also consider traditional dimensions such as production rate and quality. In this study, technology related to basic dicision method of environmentally conscious machining considered economic view was dealed. And experiments of dry type machining excluded coolant and semi-dry type machining using minimum coolant were established for the comparison of conventional machining ouputs.ng ouputs.