• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.116-118
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• 2003

정밀주조에 사용되는 왁스형을 기존의 수작업과 금형을 이용하는 방법으로 제작하지 않고 SLS형 RP로 캐스트폼형을 만들고 여기에 왁스를 함침시켜 왁스형을 제작하는 공정을 제안하였다. 왁스형의 정밀도를 향상시키기 위해 캐스트폼형 예열시간, 왁스 함침시간, 왁스 함침 회수 등 중요한 공정변수를 변화시켜 가며 왁스형을 만들었다. 왁스형의 정밀도를 측정한 결과 예열시간이 적어도 30분 이상일 때 정밀도가 우수한 제품을 얻었으며, 왁수를 두 번이상 함침할 때 정밀도가 우수하였다. 왁스형의 표면거칠기는 예열시간이 늘어날수록 향상된 표면조도를 얻을 수 있었다.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.495-503
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• 2017

Wax components can be precipitated when surrounding temperature decreases below wax precipitation temperature (WAT). WAT as well as pour point are important characteristics to evaluate the behavior of waxy oils. In this study, qualitative and quantitative evaluations of waxes in waxy model oils were presented after determining WAT and pour point. In case of anhydrous waxy model oils, ASTM D2500 may be most useful to determine WAT because of the transparent nature of model oils. With same apparatus, ASTM D97 is also applicable to determine the pour point of waxy oils in a serial determination. In case of emulsified model oils, however, it is difficult to measure WAT because of its opaque nature. This study employed FTIR spectroscopy to determine wax precipitation temperature and discussed the effect of emulsion state regarding the values of WAT. Further study would be needed to conclude the effect of water contents to WAT values in case of emulsified waxy oil.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.6
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• pp.662-669
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• 2015

There has been an increased interest in the mitigation of wax deposition because wax, which usually accumulates in subsea oil-production systems, interrupts stable oil production and significantly increases the cost. To guarantee a required oil flow by mitigating wax deposition, we need to obtain a reliable estimation of the wax deposition. In this research, we perform simulations to understand the major mechanisms that lead to wax deposition, namely molecular diffusion, shear stripping reduction, and aging. While the model variables (shear reduction multiplier, wax porosity, wax thermal conductivity, and molecular diffusion multiplier) can be measured experimentally, they have high uncertainty. We perform an analysis of these variables and the amount of water and gas in the multiphase flow to determine these effects on the behavior of wax deposition. Based on the results obtained during this study for a higher wax porosity and molecular diffusion multiplier, we were able to confirm the presence of thicker wax deposits. As the shear reduction multiplier decreased, the thickness of the wax deposits increased. As the amount of water increased, there was also an increase in the amount of wax deposits until 40% water cut and decreased. As the amount of gas increased, the amount of wax deposits increased because of the loss of the light hydrocarbon component in the liquid phase. The results of this study can be utilized to estimate the wax deposition behavior by comparing the experiment (or field) and simulation data.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.2
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• pp.99-103
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• 2010

Waxes, or long-chain hydrocarbons, may be obtained naturally from animals, vegetables, and mineral waxes, or may be synthesized. The oil-wax gels are widely applied to lots of cosmetics such as lipsticks. For example, the lipstick texture is strongly dependent on the glossiness of the oil-wax gels. Extensive research has been carried out to investigate the lattice structure of wax mixture in pure solvents (hydrocarbons) and defined mixtures. However, only a limited amount of work has been published on the lattice structure of wax matrixes in undefined mixtures. The objective of this study was to investigate the relationship between the lattice structure of ceresin wax and different wax mixtures and the glossiness of oil-wax gels. Recently visual factors such as the glossiness of skin are generally known as the words to express the beauty. The mechanism of glossiness has been suggested to understand the changes that occur in the lattice structure of the wax matrixes when they are forming gels and also the effects of the nature of solvent. The present work investigates the lattice structure of the wax matrixes and glossiness of oil-wax gels obtained from ceresin and microcrystalline wax as well as of the gels formed by different waxes in solvent.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.1-8
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• 2016

When the oil is produced in the low temperature environment, wax can be accumulated in petroleum production system(pipeline, riser) and causes problems such as pipeline stucking, disturbance of the oil production. These problems can be lead to time-consuming and economic losses for flow assurance. For prediction and mitigation of wax deposition, it is necessary to measure the Wax Appearance Temperature(WAT) which is a temperature when the wax crystals start to be formed. WAT standard measurement method of transparent oil has to determine the cloud point of sample to the naked eye and cannot be applied to continuous change of the temperature. In this study, wax behavior of transparent oil samples are recorded depending on temperature using Visualized WAT Measurement System. Also, WATs of transparent oil samples are measured by image processing and compared with the result of the standard method.

• Journal of Adhesion and Interface
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• v.13 no.1
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• pp.38-44
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• 2012

Surface properties and curing behavior of UV-initiated photopolymerization with and without wax have been investigated by pendulum hardness, pencil hardness, gloss, photo-differential scanning calorimetry (photo-DSC) and SEM. In addition, the influence of wax type (paraffin wax, PE wax) on the various properties of UV cured films was studied. The results showed that the wax type was the significant factor affecting gloss and surface hardness of UV cured films. Specially, the photo-DSC results showed that ${\Delta}H$ for the UV cured films containing paraffin wax was higher than the corresponding values for the formulation without wax and with PE wax. The observed results clearly demonstrate that the photopolymerization of UV curing with paraffin wax in an air atmosphere is less inhibited by the oxygen compared to UV curing without wax and with PE wax.

• Journal of Energy Engineering
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• v.24 no.2
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• pp.1-8
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• 2015

Wax deposition hinders oil flow assurance. Huge amount of money and time were required for mitigation of wax deposition in the oil field. For prediction and mitigation of wax deposition problem, Wax Appearance Temperature(WAT), which is the temperature at which the first wax crystals start to form, needs to be measured in advance. There is a standard method which is optical way to measure the WAT of transparent oil. However, standard method cannot be applied to opaque oil which is common produced oil in the field. In this study, WAT of three transparent oil samples were measured using heat flux variation analysis, viscosity variation analysis and density variation analysis, and compared with WAT measured by standard method. As a result, WAT measured by density variation analysis is the more reliable than heat flux variation analysis and viscosity variation analysis. WAT of two opaque oils were measured using density variation analysis.

• Proceedings of the KAIS Fall Conference
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• 2002.05a
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• pp.49-51
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• 2002

산업 현장에서 많이 사용되는 정밀주조법은 왁스형 제작 공정이 수작업으로 이루어지기 때문에 시간과 비용이 많이 소요된다. 이를 쾌속조형기를 이용하여 신속하고 정밀하게 왁스형을 제작하는 공정을 개발하였다. 먼저 3D CAD 데이터를 SLS형 쾌속조형기에서 캐스트폼 분말을 사용하여 캐스트폼형을 만든다. 오븐에서 왁스를 용융시키고 여기에 캐스트폼형을 넣어서 왁스가 캐스트폼형의 공극에 함침되도록 한다. 천천히 냉각시킨 후 꺼내면 왁스형이 완성되며 이를 일반적인 정밀주조공점을 거치면 최종 금속 주물이 완성된다. 이 신공정을 이용함으로서 제작시간과 비용이 크게 단축되었으며 제품의 정밀도가 향상되었다.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.497-504
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• 2015

Apart from hydrates, asphaltenes, and inorganic minerals, paraffinic waxes are also very important in flow assurance area. Evaluation of wax gel behavior has been important as off-shore oil recovery becomes more popular in oil production. Restart after either planned or emergency shutdown requires pump operation in high pressure since a waxy oil forms troublesome gel. In this paper, vane method is introduced to determine wax gel strength by determining yield stress. Prediction of gel strength are discussed in qualitative and quantitative manners.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.670-678
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• 2017

Self-emulsifiable polyethylene (PE) wax was prepared using acrylic acid grafted PE wax with potassium hydroxide and various emulsifiers for the economic production of PE wax emulsion. Modification reaction completion was confirmed that the peak from carbonyl group of acrylic acid disappeared and the new peak from carboxylic acid salts appeared in the FT-IR (Fourier transform infrared) spectrum data. Self-emulsifiable properties of the modified PE wax were investigated by the emulsion size and the stability of wax emulsion without any additional emulsifiers. According to self-emulsifiable properties, the emulsion size and stability were varied on the concentration and structure of the emulsifier. The greater emulsion concentration and hydrophilic poly(ethylene oxide) (PEO) characteristics of the emulsifier resulted in the smaller emulsion size and better emulsion stability. In addition, the use of emulsifiers mixture was more effective to obtain smaller size and uniform distribution of emulsion than that of single emulsifier in PE wax modification reaction. Especially, modified PE wax with OAE-5 and LAE-15 emulsifiers mixture shows excellent performance in terms of the smallest emulsion size ($4.34{\mu}m$) and emulsion stability.