• Journal of the Korean Ceramic Society
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• v.28 no.11
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• pp.917-925
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• 1991

For the present experiment five Portland cement mortars are in order: mortars with two different water/ cement ratios (W/C=0.45 and 0.50, each having no chemical additive), and those with an additive such as superplasticizer, air-entraining agent or water-repelling agent. We fix the W/C ratio of mortars having additive so that their pastes can yield the same workability as that of the cement mortar of W/C=0.50 with no additive. It is shown that the freeze-thaw resistivity depends heavily on the characteristic of wide pores. Despite a good deal of wide pores, the air-entrained specimen shows a good freeze-thaw resistivity due to appropriate air-pores. And also the specimen with water-repelling agent, which proves to cause the microstructure to become hydrophobic, make good resistance to freeze-thaw cycles in spite of its high wide-porosity. Our suggestion is that the freeze-thaw durability of Portland cement mortar/concrete can be more effectively enhanced by using air-entraining agent or water-repelling agent, and simutaneously by taking proper measures against foaming and/or the increased tendency of wide-pore building due to additive.

• Applied Chemistry for Engineering
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• v.4 no.4
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• pp.760-769
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• 1993

Solvent-free low foaming scouring agents(LFSA) were prepared by blending of polyoxyethylene(30) octadecylbenzylammonium chloride(POAC), block copolymer of propylene oxide-ethylene oxide[p(PO-b-EO) glycol], Sedlan FF-200(FF-200) and sulfonic acid-amine condensate of polyoxyethylene(10) nonylphenyl ether(PSAC). In consequence of several tests, FF-200/POAC/p(PO-b-EO) glycol/PSAC/water (20g/10g/5g/5g/60g) mixture (LFSA-5) showed good cleaning power, penetrating ability, emulsifiability and stability to alkali, and gave less problem in water pollution. Scouring effect of LFSA-5 was investigated by the change of percentage of exhaustion before and after scouring at various dyeing temperatures. The percentage of exhaustion of the unscoured PET fabric was 4.5% at $70^{\circ}C$, while that scoured with LFSA-5 was 1.3% at the same temperature, which proved LFSA-5 to be a good scouring agent. Moreover, the foaming power of LFSA-5 measured by Ross and Miles method was 6mm foam height immediately after foaming, and that measured by Ross and Clark method was less than 300mm foam height at $30^{\circ}C$, and 20mm at $80^{\circ}C$. As a result, LFSA-5 proved a good low foaming scouring agent.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.30 no.1
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• pp.63-72
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• 2024

Poly (butylene adipate-co-terephthalate) (PBAT) is one of the representative biodegradable polymers with high ductility and processability to replace petroleum-based polymers. Many investigations have been conducted to broaden the applications of PBAT in a variety of industries, including the food packaging, agricultural mulching film, and logistics and distribution fields. Foaming process is widely known technique to generate the cell structure within the polymer matrix, offering the insulation and light weight properties. However, there was no commercially feasible foam product based on biodegradable polymers, especially PBAT, and maintaining a proper melt viscosity of the polymer would be a key parameter for the foaming process. In this study, chemical foaming agent and cross-linking agent were introduced to PBAT, and a compression molding process was applied to prepare a foam sheet. The correlation between cell morphological structures and mechanical and physical properties was evaluated. It was found that PBAT with foam structures effectively reduced the density and thermal conductivity, allowing them to be suitable for applications such as insulation and lightweight packaging or cushion materials.

• Journal of the Korean Professional Engineers Association
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• v.17 no.3
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• pp.22-31
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• 1984

Sardine ant mackerel so called dark muscled fish have been underutilized due to the disadvantages in bloody meat color, high content of fat, and postmortem instability of protein. Recent efforts were made to overcome these defects and develope new types of product such as texturized protein concentrates and dark muscle eliminated minced fish. Approach of this study is based on the rapicl dehydration of foamed fish-starch paste by dielectric heating. In process comminuted sardine meat was washed more than three times by soaking and decanting in chilled water and finally centrifuged. The meat was ground in a stone mortar added with adequate amounts of salt, foaming agent, and other ingredients for aid to elasticity and foam stability. The ground meat paste was extruded in finger shape and heated in a microwave oven to give foamed, expanded, and porous solid structure by dehydration. Dielectric constant ($\varepsilon$′) and dielectric loss ($\varepsilon$") vcalues of sardine meat paste were influenced by wavelength and moisture level. Those values at 100KHz and 15MHz were ranged 2.25∼9.86 ; 2.22∼4.18 for $\varepsilon$′ and 0.24∼19.24 ; 0.16∼1.25 for $\varepsilon$", respectively, at the moisture levels of 4.2∼13.8％. For a formula for fish-starch paste preparation, addition of 20∼30% starch (potato starch) to the weight of fish meat, 2∼4% salt, and 5∼10% soybean protein was adequate to yield 4∼5 folds of expansion in volume when heated. Addition of egg yolk was of benefit to micronize foam size and better crispness. In order to provide better foaming and dehydration, addition of 0.2∼0.5% sodium bicarbonate foaming agent, was proper to result in foam size of 0.5∼0.7mm and foam density of 200∼400/$\textrm{cm}^2$ which gave a good crispness.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.93-98
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• 2005

The purpose of this study was to analyze the compression strength research by aerated concrete as mixing ratio This Study used foaming-agent and produced aerated concrete by pre-foam way that is used in construction site. An experiment changes unit cement amount, w/c and the glass fiber mixing rate and 'measured capacity change, unit capacity weight and compressive strength. The results obtained from experimental study are as following; Research to reduce unit capacity weight in condition more than unit cement amount 500kgf is considered should be gone side by side. The highest compressive strength result appeared in aerated concrete that cement amount 600kgf and w/c ratio $45\%$, $50\%$. compressive strength was increased maximum $34%$ when glass fiber $0.7\%$ addition cause by coherence enlargement to enlargement of cement paste and glass fiber addition per unit volume

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.261-266
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• 2003

This study is to investigate the heating value and noxious gases generation such as CO, NO and $SO_2$ known as dangerous gas for human from specimen made of cement and lightweight aggregate. The most quanity of CO gas is generated in EPS(Expanded Poly Styrene), core of commercial sandwich panel. Although specimens mainly composed of cement discharged the relatively less CO gas than organic core such as EPS, specimens which SBR was added discharged the very much amount of CO gas similar to EPS and especially, specimens including foaming agent, gas foaming agent or redipersible powder of VA/VeoVa showed the good properties in the generation of CO gas. From the standpoint of the generation of NO and $SO_2$ gas, both the core of commercial sandwich panel such as EPS, Glass wool and specimens made with polymer dispersion such as St/BA and SBR discharge the very much amount of NO and $SO_2$ gas in comparison of the other specimens. From this study, it was confirmed that organic materials such as core of commercial sandwich panel dischared much more noxious gas than specimens composed of cement and inorganic lightweight aggregate.

• Journal of Powder Materials
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• v.21 no.6
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• pp.454-459
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• 2014

In this study, the porous ceramic filter was developed to be able to remove both dust and hazardous gas contained in fuel gas at high temperature. The porous ceramic filters were fabricated and used as a catalyst support. And the effects have been investigated such as the mean particle size, organic content and addition of foaming agent on the porosity, compressive strength and pressure drop of ceramic filters. With the increase of mean powder size and the organic content for the cordierite filter, the porosity was increased, but the compressive strength and pressure drop were decreased. From the results of the research, the optimum condition for the fabrication of ceramic filters could be acquired and they had the porosity of 58%, the compressive strength of 13.4 MPa and the pressure drop of 250 Pa. It was expected that this ceramic filter was able to be applied to the glass melting furnace, combustor, and dust/toxic gas removal filter.

• Journal of the Korean Applied Science and Technology
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• v.20 no.2
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• pp.81-86
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• 2003

To prepare alkaline degreasing agents(SADAs), tetrasodium pyrophosphate(TSPP), $Na_2CO_3$, Tetronix T-701 (T-701), Na-dioctyl sulfosuccinate(303C), Demol C, and MJU-100A were blended. The prepared degreasing agents were tested with steel specimens and the results were as follows. The degreasing powers of SADA-6($Na_2CO_3$ 50g/TSPP 25g/T-701 10g/303C 15g/Demol C 12g/MJU-100A 8g/water 130g mixture) for press-rust preventing oil were 98% and 99% degreasing at 4wt%, 70 $^{\circ}C$ and 90 $^{\circ}C$, respectively; for quenching oil, the degreasing power of SADA-6 was 92% degreasing at 4wt% and 70 $^{\circ}C$. From these results, it was proved that the SADA-6 exhibits a good degreasing power. Foam heights measured immediately after foaming by Ross & Miles method and Ross & Clark method at 6wt% and 60 $^{\circ}C$ were 16mm and 40mm, respectively. SADA-6 was proved a good low foaming degreasing agent.

• Journal of the Korean Applied Science and Technology
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• v.10 no.2
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• pp.35-40
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• 1993

Alkaline cleaning agent(ACA) was prepared by blending of POE(4)octadecylmine(S-204), $Na_2CO_3$, sodium orthosilicate(Na-OSi). Tetronix T-701(T-701), and MJU-100A. The physical properties of ACA tested with steel specimen showed the following results. The cleaning powers of ACA-6(S-204 80g/$Na_2CO_3$, 160g/Na-OSi, 80g/T-701, 60g/MJU-100A, 20g mixture) for press-rust preventing oil was 98% and 99% degreasing at 2wt%, $70^{\circ}C$ and $90^{\circ}C$, respectively : for quenching oil, the cleaning power of ACA-6 was 95% degreasing at 2wt% and $70^{\circ}C$. From these results, it was ascertained that ACA-6 exhibited a good cleaning power. Foam heights measured immediately after foaming by Ross & Miles method and Ross & Clark method at 3wt%. $60^{\circ}C$ were 17mm and 40mm, respectively. As the result, ACA-6 was proved a good low foaming cleaning agent.

• Textile Coloration and Finishing
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• v.31 no.3
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• pp.187-194
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• 2019

Blowing film was prepared using polyester elastomer with thermally expandable microcapsule to investigate the optimum blowing properties and the film making process. Physical properties including specific gravity, blowing efficiency, foaming shape, tensile strength and elongation of polyester film were tested by varying the process condition of temperature and revolution per minutes of the extruder. The lowest specific gravity of 0.709 can be achieved with excellent foaming cells at $210^{\circ}C$ and 50 RPM conditions. The highest tensile strength and elongation was shown at $210^{\circ}C$, 100 RPM and $230^{\circ}C$, 25 RPM conditions. However, most of the prepared polyester films showed over $1kg_f/mm^2$ of tensile strength which is reasonable value to use in film applications.