• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_3
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• pp.1315-1324
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• 2022

The need for remanufacturing ships and various mechanical components continues to increase along with environmental problems. Research on remanufacturing is being carried out in various fields, but research on cleaning is quite insufficient. In particular, there is no research on the cleaning-ability of diverse mechanical components. In order to increase the life cycle of mechanical components, remanufacturing must be considered from the step of design. Particularly, it is also very important to evaluate the degree of easiness in cleaning to remove various pollutants generated by long-term use quickly as well as easily. In this study, the degree of easiness in cleaning is defined as cleaning-ability. In fact, remanufacturing components can be easily done only when cleaning-ability is set high from the step of design. The purpose of this study is to evaluate the cleaning-ability of ships and various mechanical components. The details of easiness in cleaning are cleaning and drying identification, accessibility to cleaning tools, convenience in cleaning, and convenience in drying. This study presents a quantitative procedure to evaluate cleaning-ability, derived various factors influencing each of the details of easiness and their ranges, and gave scores to the factors according to their ranges. The weight was also calculated for the details of easiness in cleaning and the factors. Lastly, this researcher suggests a scoring procedure to evaluate cleaning-ability quantitatively and the total weight of cleaning-ability.

• Clean Technology
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• v.14 no.2
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• pp.95-102
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• 2008

In order to choose alternative environmental-friendly cleaning agents, it is very important in the present point that the systematic selection procedures should be introduced and applied to the industry through the evaluation of their cleaning ability, environmental characteristics, and economical factors, and that the objective and effective evaluation methods of cleanliness should be established for the industry. Thus, a novel cleaning evaluation method utilizing optically stimulated electron emission (OSEE) among various methods of cleaning ability was studied in this study. The contaminants used in this cleaning experiments were flux, solder, grease, cutting oil, and mixed soil of 35% grease and 65% cutting oil. The cleaning agents developed or prepared in our laboratory were employed and their cleaning ability were comparatively evaluated by the OSEE, gravimetry and contact angle methods. The experimental results in this work showed that flux cleaning efficiency measured by the OSEE method was similar to that of the gravimetric method, but that the OSEE method could not be compared with gravimetric method for the case of solder or grease cleaning because the contaminants radiate or absorb ultra-violet light. In case of cutting oil cleaning, the gravimetric method indicated its limitation of cleaning efficiency of cutting oil since it showed cleaning efficiency of 100%, even though residual soil remaining on the substrate surface a little after its cleaning. The comparative experimental results of cleaning ability evaluated by the OSEE- and contact angle measurement methods showed that they were similar in case of cleaning of flux, mixed soil and cutting oil. It was judged that the contact angle measurement method could evaluate the cleaning ability more precisely than the OSEE method for cleaning solder and grease.

• Clean Technology
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• v.10 no.2
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• pp.73-87
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• 2004

In most of industrial fields, cleaning is employed for removing soils on their products or parts. Halogenated cleaning agents such as CFC-113, 1,1,1-TCE(1,1,1-trichloroethane), MC(methylene chloride) and TCE (trichloroethylene) have been used as cleaning ones in most of companies in the world since their excellent performance of cleaning ability and good material compatibility. However, CFC-113 and 1,1,1-TCE which are ozone destruction substances are not used any more in the advanced countries because of the which are ozone destruction substances are not used any more in the advanced countries because of the Montreal protocol. MC and TCE are now used restrictively at small part of industrial fields in most of countries since they are known to be hazardous or carcinogenic materials. Thus, it is indispensible that the alternative cleaning agents which are environmental-friendly and safe, and show good cleaning ability should be developed or utilized for replacement of the halogenated cleaning agents. Aqueous/semi-aqueous cleaning agents are evaluated to be promising alternative ones among various alternatives in environmental and economical view point. In this study, commercially available 12 aqueous and 6 semi-aqueous cleaning agents were selected and their physical properties, cleaning abilities, rinsing abilities and recycling of contaminated rinse water were measured and analyzed. Aqueous cleaning agents with higher wetting index showed better cleaning ability compared with those with lower wetting index. However wetting index did not have any correlation with cleaning ability in semi-aqueous cleaning agents. It was observed that soil concentration in aqueous and semi-aqueous cleaning agents should be maintained below the certain concentrations which depend on types of clearing agents. More than 70% soils in contaminated rinse water by some of aqueous and semi-aqueous clearing agents could be separated by simple settling method. This means that some cleaning agents with high oil-water separation efficiency will be effiective for recycling oil-contaminated rinse water. It was found that contaminated rinse water with aqueous agents was purified easiy by ultrafiltration method with PAN membrane of 30 kDa.

• Clean Technology
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• v.14 no.3
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• pp.184-192
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• 2008

Fluoride-type cleaning agents such as 2,2,2-trifluoroethanol (TFEA) and hydrofluoroethers (HFEs) do not destroy ozone in the stratosphere and have low global warming potential compared to hydrofluorocarbons(HFCs) and hydrochlorofluorocarbons (HCFCs). Especially, HFEs which have no flash point are paid attention as next generation type of cleaning agents for chlorofluorocarbons (CFCs) since they are safe in handling and have excellent penetration ability compared to hydrocarbon cleaning agents with low flash point. Here, the physical properties and cleaning abilities of fluoride-type cleaning agents such as TFEA, HFE-7100, HFE-7200, HFE-476mec, HFE-449mec-f, AE-3000 and AE-3100E and silicide-type cleaning agents such as trifluoroetoxytrimethylsilane (TFES) and hexamethyldisilazane (HMDS) were measured and compared with those of ozone destruction substances such as CFC-113 and 1,1,1-trichloroethane. They were also compared with toxic methylene chloride (MC) and isopropyl alcohol (IPA) which are now being used as an alternative cleaning agents. As a result, TFEA and HFEs had lower cleaning ability for removal of various soils compared to chloride-type cleaning agents, but they showed excellent cleaning ability fur fluoride-type soils. TFES and HMDS also showed excellent cleaning ability for silicide-type soils.

• Clean Technology
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• v.12 no.1
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• pp.1-9
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• 2006

Aqueous cleaning agents which are considered to be environmental-friendly and promising alternative ones among various industrial cleaning agents were evaluated in this words. In order to formulate aqueous cleaning agents, primary alcohol ethoxylates with 3, 5 and 7 moles of ethylene oxides among nonionic surfactants were selected as main surfactants. And anionic surfactants and alcohols were chosen as their cosurfactants. Builders such as NaOH, KOH, $Na_2CO_3$ and $NaHCO_3$ were also evaluated as additives for improvement of cleaning efficiency of aqueous cleaning agents. The experimental results of cleaning ability tests show that introduction of anionic surfactant TLS as cosurfactant in alcohol ethoxylate-based aqueous solution gives the best cleaning efficiency for removing mixed soil of cutting oil and grease. NaOH and $Na_2CO_3$ are also shown to play an important role for improvement of cleaning efficiency in a aqueous cleaning agent.

• Clean Technology
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• v.14 no.2
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• pp.103-109
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• 2008

In this study, in order to develop evaluation method of the cleaning efficiency of residual flux which remains on the surface after soldering with solder paste, a specially designed metal tool is used to reduce spread uncertainty of flux while soldering. Using this tool, the measurement of cleaning efficiency of flux after soldering for some typical alternative semi-aqueous cleaners and 1,1,1-TCE by weighing method was conducted. As the test result of cleaning efficiency for each cleaner at several different cleaning times, the precision of the data is confirmed to within about 4% relative standard deviation (RSD) range. So, it is considered that this would be a good evaluation method for evaluating the cleaning efficiency of the residual flux which remains after solder paste soldering in the alternative cleaning. The results of this test method shows that the cleaning efficiency of ST 100SX and Neozal 750H in the cleaning of residual flux was better than other semi-aqueous cleaners, but its cleaning efficiency was clearly inferior to 1,1,1-TCE.

• Clean Technology
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• v.12 no.4
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• pp.250-258
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• 2006

CFC compounds such as CFC-113 and 1,1,1-TCE, etc. have been used in various industries due to their excellent chemical stability, thermodynamic characteristics, non-inflammability and anti-corrosiveness. However, in oder to protect the earth environment, "the Montreal Protocol on substances that deplete the ozone layer" was adopted in 1989 for prevention of production and utilization of these CFC compounds and alternative cleaning agent have been required in the industry. The objective of this study is to develop non-aqueous cleaning agents that do not require major change of cleaning system, have excellent cleaning efficiency, are favorable to the environment, are harmless to the human body, and are not generated corrosive materials. In this work, non-aqueous cleaning agents have been formulated with glycol ether series and paraffinic hydrocarbon series with siloxane, and their physical properties and cleaning efficiencies were analyzed and compared with those of regulated materials. As a result of physical properties measurement of the formulated cleaning agents, it is expected that they may have good penetration ability into contaminated materials due to their properties with low density and low surface tension. Measurement of flash point and vapor pressure of the cleaning agents will be helpful for evaluation of their safety and working environment. The experimental results of cleaning flux, solder and grease by the formulated cleaning agents show that their cleaning abilities of soils were good and that there were no residues on the substance after cleaning. Therefore, alternative cleaning agents which have equivalent cleaning ability to regulating materials, good penetration ability and low hazard to human body, have been developed in this work.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.688-694
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• 2009

A spray-type cleaning agent in utilizing dust-remover on PCB was chosen to study the cleanliness test and efficiency. In order to choose alternative environmental-friendly cleaning agents, it is important that the systematic selection procedures should be introduced and applied through the evaluation of their cleaning ability, environmental characteristics, and economical factors, and that the objective and effective evaluation methods of cleanliness should be established for the industry. A novel cleaning evaluation method with scanning electron microscopy/energy-dispersive X-ray analysis of surface observation evaluation method and an infra-red thermography camera(THERMOVISION A20 model) was studied in this work. The sound card(CT-2770 model) cut by $2{\times}2cm$ size was used as a part, and before and after the spray cleaning, the cleanliness was observed by the image analyzer of SEM and further the removal efficiency of dust was quantitatively evaluated by the component analysis of EDX. For the parts of P4TE model motherboard and IPC-A-36 PCB plate, before and after the spray cleaning, temperature differences were measured and compared at room temperature and 50 oven temperature by an infra-red thermography camera in the contaminants of dust and iron powder.

• Clean Technology
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• v.13 no.2
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• pp.143-150
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• 2007

The objective of this study is to develop hydrocarbon-based cleaning agents by blending paraffins, glycol ethers and siloxanes in oder to effectively clean contaminants such as flux, solder and grease. And the effect of cleaning ability by wetting index, aniline points and solubility parameter of the formulated hydrocarbon-based cleaning agents were studied in this work. The formulated hydrocarbon-based cleaning agents were prepared on the base of physical properties of their individual components. Wetting indexes and aniline points of their were measured through experiments and solubility parameters of their were calculated based on the Hansen's equation. In this study, evaluation of cleaning ability by cleaning agents were carried out using contaminants such as flux, solder, and grease. The experimental results showed that the cleaning ability of the formulated cleaning agents was excellent in cleaning contaminants such as flux, solder and grease and that the influencing parameters on their cleaning efficiency were found to be different according to contaminant types. MC($20.3MPa^{1/2}$), DF-1 ($24.2MPa^{1/2}$) and DF-2($21.5MPa^{1/2}$) with similar solubility parameter as flux ($21.3MPa^{1/2}$) showed 100% cleaning efficiency within 3 minutes in flux cleaning. And CFC-113, MC and 1,1,1-TCE with low aniline point less than $-20^{\circ}C$ showed excellent cleaning efficiency in solder cleaning. DG-1($16.2\;MPa^{1/2}$) and DG-2($15.5\;MPa^{1/2}$) with similar solubility parameter as grease($15.0{\sim}17.0\;MPa^{1/2}$) showed relatively low cleaning efficiency of grease, but CFC-113 and MC with high wetting index and low aniline point showed good cleaning efficiency in grease cleaning. As a result of this study, the hydrocarbon-based cleaning agents alternative to regulated cleaning agents such as CFC-113, 1,1,1-TCE and MC were able to be developed through properly blending paraffins, glycol ethers and siloxanes for cleaning flux, solder and grease. And it can be shown that various influencing parameters of cleaning efficiency such as wetting index, aniline point, solubility parameter and etc. of the non-aqueous cleaning agent should be reviewed for prediction of their cleaning ability and can be applied to formulation of cleaning agents.

• Clean Technology
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• v.15 no.2
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• pp.81-90
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• 2009

In this study various cleaning evaluation methods were tested and comparatively evaluated to help cleaning industry. In order to select alternative cleaning agents objectively and systematically, various cleaning evaluation methods such as gravimetric, optically simulated electron emission (OSEE), contact angle, and analytical instrument methods were employed for cleaning contaminants such as flux, solder and grease. The analytical instruments used in this work were Fourier transform infrared spectroscopy (FTIR), ultraviolet visible spectroscopy (UV-VIS) and high performance liquid chromatography (HPLC). The gravimetric method was able to measure cleaning efficiencies easily and simply, but it was not easy to analyze them precisely because of its limitation in the gravimetric measurement. However, the OSEE technique was able to measure quickly and precisely the clean ability of cleaning agents in comparison with the gravimetric method. The contact angle method was found to be necessary for taking special precaution in its application to the cleaning evaluation due to possible formation of tiny organic film on the substrate surface which might be generated from contaminants and cleaning agents. In case of precision analysis that cannot be done by gravimetric method, fine analytical instruments such as UV-VIS, FTIR and HPLC could be used in analyzing trace amount of flux, solder and grease quantitatively, which were extracted from the surface by special solvents.