• 제목/요약/키워드: foam

검색결과 2,438건 처리시간 0.026초

Improving Light Stability of Natural Rubber Latex Foam

  • Shim, Chang Su;Oh, Jeong Seok;Hong, Chang Kook
    • Elastomers and Composites
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    • 제50권2호
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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.

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

  • 홍상훈;유남규;서은석;김해나;김봉주
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 추계 학술논문 발표대회
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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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Co-Ni-P-B/Ni foam 촉매에서 $NaBH_4$ 가수분해를 통한 수소 발생 (Hydrogen Generation from $NaBH_4$ Hydrolysis on Co-Ni-P-B/Ni Foam Catalyst)

  • 박대일;김태규
    • 한국수소및신에너지학회논문집
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    • 제21권5호
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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.

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

  • 민성희;손경희
    • 한국식품조리과학회지
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    • 제4권2호
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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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물유리코팅에 따른 폴리우레탄 폼의 난연성능 개선에 대한 연구 (Improvement of Flame-Retardant Performance of Polyurethane Foam Coated with Water Glass)

  • 김형준;박제원;나혜인;임형미;장가빈
    • 한국화재소방학회논문지
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    • 제34권2호
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    • pp.7-13
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    • 2020
  • 경질 폴리우레탄(Polyurethane) 폼(Foam)의 난연 성능을 개선하기 위하여 외부에 물유리를 코팅하였다. 무기질인 물유리 코팅층이 적용된 우레탄폼의 콘칼로리메터의 열방출율(Heat release rate)은 급격히 감소하였다. 폴리우레탄 표면에 코팅된 물유리는 화염에 노출되었거나 가열되었을 때 유리화 반응과 미 탈출 수분에 의한 발포현상으로 인해 유리질 폼을 형성하게 된다. 폴리우레탄 폼 위에 형성된 유리질 폼은 단열층이 되어 10 min 이상 폴리우레탄 폼의 연소를 억제하였다. 이러한 결과에 따라서 물유리는 경질 폴리우레탄 폼의 난연 특성을 개선할 수 있음을 확인하였다.

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

  • 이장원;임우섭;김성수;이동호
    • 한국화재소방학회논문지
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    • 제26권5호
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    • pp.73-78
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    • 2012
  • 본 연구는 압축공기포 소화설비의 소화성능을 평가하기 위해 포헤드 설비를 이용하여 실험을 진행 하였다. 압축공기포 소화설비는 포수용액에 압축공기를 혼입하여 포를 발생시키는 방식으로 해외에서는 원거리 방수가 가능하고 물 사용량을 줄여 수손피해를 최소화할 수 있는 압축공기포 소화설비(CAFS: Compressed Air Foam System)가 많이 활용되고 있다. 본 연구에서는 UL162 기준으로 수성막포 3 % 포 소화약제를 적용하여 기존의 공기 혼입 방식에 의한 포 소화설비와 압축공기포 소화설비간 비교 실험을 통하여 소화 성능 효과를 비교 분석하였다. 압축공기포 소화설비의 공기 혼입 비율은 포 수용액과 1 : 1의 부피 비율로 하였으며 발포유량은 각각 140 L/min, 160 L/min, 180 L/min, 200 L/min으로 변화를 주면서 소화효과를 검증하였다. 그 결과 소화 성능면에서는 압축공기포 소화설비가 공기 혼입 방식보다 모든 유량 조건에서 소화시간이 빠르게 나타났다.

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

  • Kim, Jin-Man;Jeong, Ji-Yong
    • 한국건축시공학회지
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    • 제12권1호
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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.

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

  • 김종율;정규동;양준서
    • 한국군사과학기술학회지
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    • 제7권4호
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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.

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

  • 김공주;박병기;조은진;김지주;이재덕
    • 한국염색가공학회지
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    • 제4권3호
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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
    • 한국분말재료학회지
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    • 제22권2호
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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.