• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.22-23
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• 2016

This study analyzes the properties of foam according to the concentration of vegetable foaming agent that is used in traditional and mixed foaming agent of developing stage, and confirms how the foams influence foamed concrete by searching for properties of foamed concrete according to replacing ratio of vegetable foaming agent and mixed foaming agent. This is for the purpose of providing basic data for the use of foamed concrete through improvement on the problem such as unstability, falling in fluidity and the strength of existed foaming agent.

• Elastomers and Composites
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• v.51 no.1
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• pp.24-30
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• 2016

Sole in the footwear usually modified with foaming agent on the polymer resin to improve the lightweightness and crush-cushion effect. In this study, we investigated rheological properties for polymer resin filled with the different type and concentration of foaming agent, capsule type foaming agent and organo-chemical foaming agent, under the time sweep test. Curing times of each polymer resin with different kind of foaming agent are delayed than reference material (epoxy resin with curing agent). In case of adding capsule type foaming agent, however, there is appropriate concentration to reduce the curing time, relatively. When foaming agent is activated, foaming force inflates the sample in contrast to condensation force of curing and then axial normal force develop to the (+) direction. Interestingly, by increase concentration of foaming agent, there is a specific point to break down the axial normal force development. The reason for this phenomenon is that coalescence of foams induce the blocking of axial normal force development.

• Journal of the Korea Concrete Institute
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• v.23 no.2
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• pp.151-158
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• 2011

Bubbles within the foamed concrete manufactured by pre-foaming method is the main factor which affects the physical properties of foamed concrete such as density, strength, and porosity. Although many researches on foamed concrete have been continuously carried out, insufficient number of researches on the properties related to bubbles in the foamed concrete has been performed except for chemical application related researches. In order to make an optimal foamed concrete, study on the bubble properties must be pursued. In order to effectively implement bubbles in the manufacturing of foamed concrete, the bubble properties must be estimated. In this study, in order to determine the bubble properties, examination of the bubble properties according to types and foaming agent concentration was performed. An foaming agent used for this test were anionic surfactant, rosin, and protein system with the foaming agent concentration range of 0.05~13%. Test parameters considered in the study were foaming rate, foam volume, drainage solution volume, and bubble size. The study results showed that, regardless of foaming agent type, higher concentration of foaming agent showed an increase in the foaming rate. Also, the results showed that concentration of foaming agent affected bubble size, drainage solution volume change, and bubble distributions. With respect to the stability of the bubble, protein foaming agent was better than anion surfactant or rosin foaming agent. With respect to the bubble shape, anion surfactant and rosin formed bubbles had polygon shape where as protein formed bubbles had spherical shape.

• Korean Journal of Materials Research
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• v.33 no.8
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• pp.323-329
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• 2023

There are many types of foam molding methods. The most commonly used methods are the pressure foaming method, in which foam resin is mixed with a foaming agent at high temperature and high pressure, and the normal pressure foaming method, which foams at high temperature without pressure. The polymer resins used for foaming have different viscosities. For foaming under normal pressure, they need to be designed and analyzed for optimal foaming conditions, to obtain resins with low melt-viscosity or a narrow optimal viscosity range. This study investigated how changes in viscosity, molding temperature, and cross-link foaming conditions affected the characteristics of the molded foam, prepared by blending rubber polymer with biodegradable resin. The morphologies of cross sections and the cell structures of the normal pressure foam were investigated by SEM analysis. Properties were also studied according to cross-link/foaming conditions and torque. Also, the correlation between foaming characteristics was studied by analyzing tensile strength and elongation, which are mechanical properties of foaming composites.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.680-683
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• 2004

This study is to obtain basic data concerned with properties of foam for foamed concrete and foaming method. Main factors of this study are types of foaming agents, temperature of solution with foaming agents, and types of foam generator. Testing items are size distribution of foam, foaming ratio to solution, and stability of foam. The results of this study were shown as follow. It is optimum condition of foam generator that length/diameter of foaming tube is 2.0, bead size within foaming tube is $4\~6mm$, and nozzle size of foaming tube is 10mm. AES and AOS are good results to produce high quality foam, and stability of foam is good in foaming temperature of $20^{\circ}C$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.585-590
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• 1997

Conventional foaming process has defects such as lower mechanical properties than ur~foaming material due to non-uniform cell distribution and environmental pollution problem caused by chemical blowing agency. So, a new foaming process such as Microcelluar plastics has been introduced to use inactive gases as a foaming agency. In order to apply Microcellular plastics for mass production process system such as extrusion, injection molding and blow molding, it needs to predict the change in material properties of polymer according to the amount of meltingas. In Polymer molding applying Microcelluar plastics, the change of viscosity among several material properties is the most important factor. Therefore, this paper is aimed to establish the method which not only finds out but also predicts the change of viscosity of ABS(Acrylonitri1e Butadiene Styrene) resin according to inert gas amount in extrusion molding.

• Architectural research
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• v.26 no.1
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• pp.13-20
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• 2024

This study is a research investigation into the properties of bubbles that affect the characteristics of foamed concrete during its production. The study examined the properties of bubbles based on the manufacturing conditions. To investigate these properties, the selected experimental factors included bead size, the length/diameter ratio of the bubble-generating tube, and compressed air. The experimental design used a design of experiments, and the test results were analyzed using analysis of variance. The foaming agent used to generate bubbles was AES (Alcohol Ethoxy Sulfate), and the method employed for bubble manufacture was the pre-foaming method. In the test results, a significant factor affecting the foaming rate of bubbles was the bead size; the highest foaming rate was observed when using 2mm beads. Bead size also primarily influenced the volume change of the aqueous solution, while other factors did not affect the foaming rate and volume change. None of the factors affected the change in bubble size, but compressed air was considered the main factor affecting bubble size and its change. The foaming rate and volume change of the aqueous solution showed a high correlation with each other. Spherical bubbles in the early stage eventually transformed into angular bubbles. Moreover, over time, it was observed that the bubble size increased.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.9
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• pp.71-77
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• 2008

Microcellular foaming plastics create a sensation at polymer industrial for lowering product costs and overcoming a lowering of mechanical intensity. Among many advantages, microcellular foaming plastics is well known to have a good acoustical properties. This research based on the experiment of sound absorption and transmission characteristics inquire into acoustical properties of microcellular foaming plastics. Difference of transmission loss of microcellular foaming plastics and solid materials was defined as cell effect. Also, cell effect is expressed by sound reflection and sound absorption. This study is expected to fundamental research to present economical, functional alternative plan for products using sound absorption and transmission materials.

• Elastomers and Composites
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• v.29 no.3
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• pp.213-225
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• 1994

The Purpose of this dissertation is to study the preparation technique and physical properties of expanded rubber. The respective samples of NR, NBR and the standard compounds of EPDM rubber were prepared by mixing plasticizer DOP and LCR in various ratio. And their vulcanization characteristics, physical properties and foaming states were studied. Vulcanization characteristics were investigated using cure curve that had been obtained from Oscillating Disk Rheometer study, and the microscopic photographs of foaming states were obtained using electron microscope. The vulcanization characteristics of the samples, DOP 30phr and LCR 30phr, were found to be suitable. The tests, like hardness test and resilience, tensile test on the physical properties of each sample showed that plasticizing efficiencies of DOP and LCR were almost the same. Oil resistance test exhibited DOP was better than LCR and compression set test showed LCR was excellent plasticizer. The foaming states of NR, EPDM compounds were uniform, but those of NBR compounds were not uniform. Consequently vulcanization characteristics, physical properties and foaming states of all the samples satisfied the SAE requirements.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.163-166
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• 1997

Aluminium foam material is a highly porous material having complicated cellular structure defined by randomly distributed air pores in metallic matrix. this structure gives the aluminium a set of properties which cannot be achieved by any of conventional treatments. The properties of aluminium foam material significantly depend on its porosity, so that a desired profile of properties can be tailored by changing the foam density. Melting method is the one of foaming processes, which the production has long been considered difficult to realize becaues of such problems as the low foamability of molten metal, the varying size of. cellular structures, solidification shrinkage and so on. These problems, however, have gradually been solved by researchers and some manufacturers are now producing foamed aluminum by their own methods. Most of all, the parameters of solving problem in electric furnace were stirring temperature, stirring velocity, foaming temper:iture, and so on. But it has not considered about those in induction heating, foaming velocity and foaming temperature in semi-solid state yet. Therefore, this paper presents the effects on these parameter to control cell size, quantity and distribution.