• Title/Summary/Keyword: foam

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Improving Light Stability of Natural Rubber Latex Foam

  • Shim, Chang Su;Oh, Jeong Seok;Hong, Chang Kook
    • Elastomers and Composites
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    • v.50 no.2
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    • pp.81-86
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    • 2015
  • In this study, natural rubber latex foam was prepared in order to replace commercialized polyurethane foams as a car seat material. Physical properties of the latex foam were investigated and the light stability was improved. The latex foam was mixed in an aqueous solution state, and the degree of foaming and the accelerator ratios were appropriately controlled. Tensile properties, hysteresis and dynamic mechanical properties of the latex foam were measured to compare with those of polyurethane foams. UV light absorbers and radical scavengers were added for improving light stability of the latex foam. Xenon lamp test was conducted to investigate the effects of the reagents on light stability. Our results revealed that the prepared latex foam including a light absorber with an antioxidant showed excellent light stable performances.

A Study on the Foam Density and The Physical Performance of Foam Concrete According to the Foam Forming Pressure Change (기포성형 압력변화에 따른 기포밀도 및 기포콘크리트의 물리적 성능에 관한 연구)

  • Hong, Sang-Hun;You, Nam-Gyu;Seo, Eun-Seok;Kim, Han-Nah;Kim, Bong-Joo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.11a
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    • pp.38-39
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    • 2018
  • Foame concrete was used to reduce insulation problems and interlayer noise in slab. There have been no studies on the physical properties of foaming agents using foamed concrete,Only the physical properties of foamed concrete mixed with foam agent. It is judged that the density and distribution of Foams will be changed when the pressre is changed when the bubble is formed. In this study to investigate the changes of Foam density and the physical performance of foamed concrete by changing the pressure during Foam formation.

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Hydrogen Generation from $NaBH_4$ Hydrolysis on Co-Ni-P-B/Ni Foam Catalyst (Co-Ni-P-B/Ni foam 촉매에서 $NaBH_4$ 가수분해를 통한 수소 발생)

  • Park, Da-Ill;Kim, Tae-Gyu
    • Transactions of the Korean hydrogen and new energy society
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    • v.21 no.5
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    • pp.383-389
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    • 2010
  • Co-B, Co-P-B, Co-Ni-B and Co-Ni-P-B catalysts supported on Ni foam were prepared using electroless plating in the present study. The surface morphology of the catalysts/Ni foam was observed using SEM and EDS analysis. The Co-Ni-P-B/Ni foam catalyst showed the superior performance on hydrogen generation due to the uniform formation of catalyst particles on the Ni foam surface. The characteristics of hydrogen generation with Co-Ni-P-B/Ni foam catalyst was investigated at the variety of $NaBH_4$ and NaOH concentrations. Durability test was performed, resulting in the stable hydrogen generation for 6 hours.

A Study of the Foaming Poperties of Mungbean Protein Isolate (녹두 단백질의 기포특성에 관한 연구)

  • 민성희;손경희
    • Korean journal of food and cookery science
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    • v.4 no.2
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    • pp.1-9
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    • 1988
  • This study was carried out in order to study the foaming properties of mungbean protein. Mungbean protein isolate was tested for the purpose of finding out the effect of pH, addition of sucrose on foaming properties. The results were summarized as follows: 1. Foam expansion values were generally depen. dent on protein concentration to 3% protein suspension. From 1% to 3% suspension, foam expansion values increased. However over 3% suspension, the values decreased. In 1% mungbean protein suspension, the foam expansion value of suspension at pH 4.5 was greater than that of at pH9. In 3%, 5%, and 10% suspensiona the foam expansion values of suspension at pH 7 was the lowest. Foam expansion value significantly decreased by the addition of sucrose. 2. The foam stability appeared the greatest value as protein concentration increased. It appeared the greatest value at pH 4.5. When sucrose was added, the foam stability increased. The more sucrose was added, the better foam stability was.

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Improvement of Flame-Retardant Performance of Polyurethane Foam Coated with Water Glass (물유리코팅에 따른 폴리우레탄 폼의 난연성능 개선에 대한 연구)

  • Kim, Hyeong-Jun;Park, Jewon;Na, Hyein;Lim, Hyung Mi;Chang, Gabin
    • Fire Science and Engineering
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    • v.34 no.2
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    • pp.7-13
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    • 2020
  • In this study, water glass was applied as a coating material to a rigid polyurethane foam to improve the flame-retardant properties of the foam. The heat release rate of the cone calorimeter of the urethane foam, in which the inorganic water-glass coating layer was applied, decreased rapidly. The water glass coated on the polyurethane surface formed a glassy foam by foaming with water, which did not escape during the vitrification reaction when the foam or glass was heated. The glassy foam formed on the polyurethane foam became a fire-resistant insulation layer that inhibited the combustion of the polyurethane foam for more than 10 min. Water glass was found to improve the flame-retardant properties of the rigid polyurethane foam.

A Study on Fire Extinguishing Performance Evaluation of Compressed Air Foam System (압축공기포 소화설비의 소화성능 평가에 관한 연구)

  • Lee, Jang-Won;Lim, Woo-Sub;Kim, Sung-Soo;Rie, Dong-Ho
    • Fire Science and Engineering
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    • v.26 no.5
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    • pp.73-78
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    • 2012
  • This research is to evaluate the fire extinguishing performance of Compressed Air Foam System and this test was conducted using Foam Head System. Compressed Air Foam System adopt the methods of causing the foam by mixing compressed air in foam-aqueous solution, In Overseas, CAFS (Compressed Air Foam System) is generally used because long distance discharge is possible and the water damage can be minimized by reducing the water usage. In this study, Comparative analysis on fire extinguishing effect is done through test to compare the performance between Foam System applied existing air mixture method and Compressed Air Foam System applied AFFF 3 %, foam-extinguishing-agent based on UL162 standard. In Compressed Air Foam System, the volume proportion of air mixture to foam-aqueous solution is 1 to 1 and discharging flow rate is 140 L/min, 160 L/min, 180 L/min, 200 L/min each. As a result of the test, in terms of fire extinguishing performance, fire suppression time for Compressed Air Foam Systems is shorter than for General Air Mixture System in all flow conditions.

Influence of Foaming Agents on the Properties of Foamed Concretes Having Various Densities

  • Kim, Jin-Man;Jeong, Ji-Yong
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.1
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    • pp.22-30
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    • 2012
  • Four types of foaming agents, including Alcohol Ethoxy Sulfate (AES), Alpha Olefin Sulfonate (AOS), Vegetable Soap (VS), and Fe-Protein (FP), are widely used in the construction field. These have different surface tensions and viscosities in water of the same concentration, affecting the flow speed of liquid, size and distribution of foam, and foam stability. However, there is a lack of data regarding the properties of foam concrete using various foam agents. The purpose of this study is to investigate influence of foaming agents on the properties of foamed concretes with various densities. We find that the foaming agent type has little effect on the density, compressive strength, and thermal conductivity of foam concrete, but considerably affects the unit weight of foam, flow and flexural strength of foamed concrete. While almost all properties of foam concrete are affected by density in fresh or hardened state, the potential energy changed by slurry density and the viscosity of foam are dominant factors in the flowability of foam slurry.

A Study on the Pressure Increase due to the Foam Left in the Radial Slot of Propellant Grain (추진제 그레인 래디얼 슬롯내의 폼 코어에 의한 압력증가 해석)

  • Kim Jong-Yul;Jung Gyoo-Dong;Yang Jun-Seo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.7 no.4 s.19
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    • pp.125-132
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    • 2004
  • The radial slot configuration in the solid propellant grain is usually fabricated by the polyurethane foam slot former The foam cannot be easily removed from the solid propellant, some can remain in the slot. Analogue solid propellant rocket motors using polyurethane foam to shape the slot are static fired with the foam former still in place in the slot. The pressure increases at the slot part are measured and there are indications of the propellant cracks at the insulations above the slot. The pressure increase is produced at the beginning of the burning sequence as the foam will hinder the combustion gas of the burning propellant from flowing into the central bore. The pressure increase up to about 300psi is predicted for the motor tested and this pressure increase depends on the gap between the propellant and foam surfaces and remaining foam volume. This amount of pressure increase inside of the slot is estimated to cause the propellant crack. To prevent this pressure increase, minimizing the foam remainder in the slot and making sufficient chamfering at the comer of the slot entrance are suggested.

Foaming Efficiency of Anion Foaming Agent Solution to Add Dyeing Assistants (조제 첨가 음이온 발포제의 거품 효율)

  • 김공주;박병기;조은진;김지주;이재덕
    • Textile Coloration and Finishing
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    • v.4 no.3
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    • pp.82-90
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    • 1992
  • To optimize the foam dyeing procedures for polyester and polyester/nylon blended non-woven fabrics, the effects of organic solvents and surfactants were investigated by measuring the foam heights and surface tensions of the foam dyeing solution. The results of the experiments can be summarized as follows: 1) Organic solvents and surfactants (sodium lauryl sulphate: SLS) solution lower the surface tension (ST) of the water, but ST lowering rate of SLS solution is greater than that of solvents. For a 0.25% SLS solution, the minimum surface tension was 30.3 dyne/cm, which is nearly the same value for organic solvents. 2) For 0.25% SLS solutions, additional adding of a 4.0% organic solvent makes the foam height (FH) be its maximum. 3) At 0.6 g/ι dye concentration, incorporation of 0.4% SLS makes the surface tension of the foam solution be its minimum. The foam height did not show any trend due to the dye type. 4) The effect of foam stabilizers (sodium alginate (Alg-Na) and hydroxy ethyl cellulose (HEC)) were also investigated. The foam height of the foaming solution with HEC was greater than that with Alg-Na. The foam stability of the foaming solution with Alg-Na was better than that with HEC.

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Fabrication and Pore Characteristics of Cu Foam by Slurry Coating Process

  • Park, Dahee;Jung, Eun-Mi;Yang, Sangsun;Yun, Jung-Yeul
    • Journal of Powder Materials
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    • v.22 no.2
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    • pp.87-92
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    • 2015
  • Metallic porous materials have many interesting combinations of physical and geometrical properties with very low specific weight or high gas permeability. In this study, highly porous Cu foam is successfully fabricated by a slurry coating process. The Cu foam is fabricated specifically by changing the coating amount and the type of polyurethane foam used as a template. The processing parameters and pore characteristics are observed to identify the key parameters of the slurry coating process and the optimized morphological properties of the Cu foam. The pore characteristics of Cu foam are investigated by scanning electron micrographs and micro-CT analyzer, and air permeability of the Cu foam is measured by capillary flow porometer. We confirmed that the characteristics of Cu foam can be easily controlled in the slurry coating process by changing the microstructure, porosity, pore size, strut thickness, and the cell size. It can be considered that the fabricated Cu foams show tremendous promise for industrial application.