• Journal of the KSME
• /
• v.16 no.2
• /
• pp.116-121
• /
• 1976

Non-steady hot wire method was adopted to measure thermal coductivity of paraffin wax in the phases of liquid and solid for the utilization of thermal energy storage. The instrument was tested with the measurement of thermal conductivity of water at various temperatures. The reproducibility of the instrumetn was found to be ${\pm}2%$, in which the results for water agree with the literature values. The thermal conductivity of paraffin wax varies from 0.177 W/m C to 0.236 W/m C when the phase changes from liquid to solid near the melting temperature.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.763-764
• /
• 2006

Ceramic Injection Moulding (CIM) technology has been successfully used for the fabrication of Mn-Zn Ferrite part. The binder was composed by polypropylene and paraffin wax. The optimal powder loading (58% vol.) was determined by means of rheological measurements. Threedifferent parts, toroids, bending and tensile probes were injected. Thermal and solvent-thermal debinding was designed based on DSC and TGA studies of the binder. The time of the debinding cycle was reduced using n-heptane to dissolve previously the paraffin wax. Final properties have been determined and compared with uniaxial pressure parts values. The densities obtained were slightly higher than those of uniaxial pressure parts and the magnetic properties presented similar values.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.207-208
• /
• 2006

In this experimental work, the development of a multicomponent binder system based on high density polyethylene (HDPE) and paraffin wax for Powder Injection Molding of Alumina $(Al_2O_3)$ parts was carried out. The optimum composition of the injection mixture was established through mixing torque measurements and a rheological study. The maximum powder loading was 58 vol%. The miscibility of organic components and the optimum injection temperature was evaluated by thermal characterization of binder and feedstock. The thermal debinding cycle was developed on the basis of thermogravimetrical analysis of the binder. After sintering the densities achieved were closed to 98% of the theoretical one.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.40 no.2
• /
• pp.23-28
• /
• 2008

As well as crop cultivation, they could not avoid automatizing and using more environmental friendly process in cultivation of fruit. And also, the consumer ask more safe fruit which is produced with more clean method. This is why the usage of aid materials for fruit cultivation like as fruiting bags are increasing. Practical utilization of wax emulsion treated water repelling fruiting bags are developed continuously and it's properties is compared properties of nomal fruiting bags. The water repelling process was developed with wax emulsion coating. After the experiment of wax emulsion preparation from paraffin and DEA and/or OA in Lab. scale, the wax emulsion was manufactured on pilot scale. The wax emulsion coated paper was prepared in mill scale coater. The water repellency and properties of emulsion coated fruiting bags were evaluated and compared with that of current fruiting bags.

• Polymer(Korea)
• /
• v.37 no.1
• /
• pp.15-21
• /
• 2013

Encapsulation of a paraffin wax core as a phase change material with polystyrene shell and the its thermal characteristics caused by the encapsulation were studied. For the nanoencapsulation, the miniemulsion polymerization method was selected. The factors affecting the thermal properties of prepared nanocapsule particles of phase change material were analysed in aspect of the structure of crosslinking agents, amounts of surfactant, ratio of paraffin wax to monomer, and hydrophilicity of initiators. It was assumed that Oswald ripening plays the most important role in the changes of particle size, particle morphology, and thermal capacity of nanocapsule core. It was elucidated that the thermal capacity was also dependent on the hydrophilicity and crosslinking density of polystyrene shell components.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.22 no.2
• /
• pp.11-19
• /
• 2018

Viscosity measurements were conducted to investigate the rheological characteristics of aluminized paraffin wax fuel. To identify the effect of size and contents of the aluminum particles on the variation of viscosity, samples of nano- and micro- sized aluminum particles with an average particle size of 100 nm and $8{\mu}m$ were prepared and measured using a rheometer. The observed viscosity increment patterns of the nano- and micro-sized particles were vey different, and particularly above 10 wt%, where a relatively low overall regression rate is expected for nano- content fuel. It is possible that this phenomenon could cause the reduced entrainment regression rate.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.50 no.5
• /
• pp.339-347
• /
• 2022

The post chamber in hybrid rocket is installed to induce additional increase in combustion enthalpy by allowing continuous burning of the liquefied fuels. When paraffin wax fuel is used, unsteady pressure oscillations are observed only at the beginning of combustion. This study intends to investigate the effect of additional combustion of liquefied fuel droplets on the occurrence of unsteady pressure fluctuations. For this, the combustion in post-chamber was visualized and image analysis using POD(Proper Orthogonal Decomposition) technique was performed. In addition, the hypothesis was proposed on the occurrence of unsteady pressure oscillations by identifying the modes including the behavior of droplets through mode reconstruction. Conducting a series of combustion tests, the amount of liquefied fuel flowing into the post chamber and the generation of fuel droplets were controlled. Also, the changes in frequency characteristic of unsteady pressure oscillation were monitored. As a result, the unsteady pressure oscillations observed in paraffin wax combustion were the result of additional combustion of fuel droplets generated in the post chamber.

• Journal of Technologic Dentistry
• /
• v.2 no.1
• /
• pp.17-19
• /
• 1980

This study was aimed at obtaining a desirable wax pattern for inlay. The method used was to analyze, mix, and heat several kinds of waxes, comparing the temperatures of their components. The result was Type C wax. In type C the amount of paraffin was generally contained(60$\sim$70%) was reduced to 45% and there was mixed 10%-15% of carnauba, which was intended for the wax not to soften readily at low temperatures. The type C has some advantages for general use: handy preparation, high safety, and economy. The inlay waxes commonly used contracted if the temperature fell from 38 to 28, but the contraction of type C was observed to be 0.2%$\sim$0.4% in proportion to the 10 fall. This was more characteristic in mixing.

• 한국기계연구소 소보
• /
• s.19
• /
• pp.23-30
• /
• 1989

Heat transfer phenomena of solidification process of the phase change material within cylindrical can is studied experimentally. N-Eicosane paraffin wax is used for phase change material and its melting temperature is 309.8 K. In order to achieve higher heat transfer rate of latent heat storage apparatus, fins in made of copper are used in the cylindrical can. If there are fins in cylindrical can, we can know that the inward latent heat energy in paraffin can be effectively transfered to cooling water than if finless.

• Journal of Radiation Protection and Research
• /
• v.20 no.4
• /
• pp.237-243
• /
• 1995

An estimate is made on the potential generation rate of H: from radiolysis of the Paraffin-wax encapsulant Proposed for the solidified liquid concentrate wasteform. The results show that the radiolytic Production of $H_2$ from paraffin-wax-encapsulated waste is dominated by the radiation energy released from $^{60}Co$. The radiolytic production of $H_2$ will proceed at an initial rate equivalent to aproximately $4.4{\times}10^2cm^3yr^1$ in 200 litre drums that are partly filled with 120 litres of encapsulated waste. The gas production rate will fall to a value of $7.2cm^3yr^1$ after 100 years. The lower flammable limit for $H_2$ in air will be reached in about 25 years and the lower explosive limit for $H_2$ in air would not be reached in 1000years. The timescale in which these safety-related limits are reached is strongly dependent on the level of filling of each waste drum. A reduction of the air space inside each drum would reduce the time required to reach the lower flammable limit.