• Elastomers and Composites
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• v.48 no.3
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• pp.241-248
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• 2013

Polyester type polyurethane foam has low hydrolysis resistance. It was overcome with addition of acrylic polyol by quasi prepolymer method. Tensile strength and hardness of polyurethane foam contained acrylic polyol was increased with increasing of acrylic polyol contents. But split tear strength and tear strength was slightly changed. Hydrolysis resistance of polyurethane foam was measured by loss % of tensile strength. It was improved with increasing of acrylic polyol contents from 25.5g to 102g.

• Journal of the Korean Society of Safety
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• v.25 no.1
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• pp.38-43
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• 2010

The smoke density and noxious gas for phenol foam and polyurethane foam were measured according to test methods in ASTM E 662 and KS F 2271. It was observed that phenol foam had the possibility of application for sandwich panel and board compared with polyurethane foam. In the experimental results, phenol foam showed comparatively excellent property than polyurethane foam in smoke density and noxious gas. The polyurethane foam showed comparatively high smoke density and didn't meet the evaluation standard of noxious gas in KS F 2271. From the experimental results of smoke density and noxious gas, it can be said that phenol foam has both comparatively good safety and high possibility of application than polyurethane foam in the building fire of sandwich panel structure because of lower smoke density and noxious gas.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.3018-3025
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• 2000

It is possible to shorten developing process by making model using polyurethane foam in the area of automobile development process, etc. However, this skill is too difficult to be of practical use because machining is not easy due to characteristic of polyurethane foam. Domestic and foreign automobile company use clay, polyurethane foam. etc,, those are easy to handle and to make model after completing design sketch. But these materials is difficult to the machined and be worked by humans hand, There are so many difficult problem for machining by making model using polyurethane foam since cutting of elastic body like polyurethan foam has never been studied. Therefore, in this study, it is investigated to measured cutting force that is generated in case of polyurethane foam machining, and to make systematize tool compensation of polyurethane foam cutting work on automobile model by modification of tool offset method on existing steel.

• KSBB Journal
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• v.7 no.3
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• pp.172-178
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• 1992

A simple and effective method has been developed for the immobilization of lipase producing Rhizopus chinensis on polyurethane foam. In this method, the fungal cells with 1, 3 specific lipase in there inside are immobilized within the foam matrix. Four types of commercially available polyurethane foam were tested. The ultimate purpose of the process is to produce low-cost biocatalysts for lipase-catalyzed reactions, which are being increasingly used for industrial applications. Effects of several parameters were studied on the cell loading and the hydrolytic activity of intracellular lipase after acetone drying. These parameters were the type, size, and amount of polyurethane foam. In all the cases, the intracellular lipase activity obtained with the foam was approximately twice greater than that obtained in the absence of the foam.

• Journal of Biomedical Engineering Research
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• v.19 no.3
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• pp.215-224
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• 1998

This paper is fundamental study to develope the extracorporeal liver support system for patient with fulminant hepatic failure(FHF) or being expected for orthotopic liver transplantation. The polyurethane foam, which is composed of the density of 33kg/m3, the average pore diameter of 500${\mu}{\textrm}{m}$, the closed window of 60-70%, was manufactured with the prepolymer of 15% NCO-, Hepatocytes were inoculated to form spheroids in polyurethane foam. The time of spheroid formation in BSA(Bovine Serum Albumin) coated polyurethane foam was shorter than that in raw polyurethane foam. To verify the function of hepatocyte spheroids, we measured ammonia removal rate, urea and albumin secretion rate. Polyurethane foam was suitable for culture of hepatocyte spheroids. And culture of hepatocyte spheroids in polyurethane foam has high possibility in using as an extracorporeal liver support system.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.5
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• pp.209-214
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• 2016

Foam reaction injection molding (FRIM) is a widely used process for manufacturing polyurethane foam with complex shapes. Numerical model for polyurethane foam forming reaction during FRIM process has been intensively investigated by a number of researchers to precisely predict final shapes of polyurethane foams. In this study, we have identified a problem related with a previous theoretical model for polyurethane foam forming reaction. Thus, previous theoretical model was modified based on experimental and computational results.

• 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.

• Journal of the Korean Society of Safety
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• v.32 no.1
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• pp.108-114
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• 2017

According to an increase in demand for polyurethane soft foam for thermally insulated containers, the purpose of this study is based on redefining existing rigid polyurethane foam insulation KS standard which has been limited to building material-based authentication techniques. Since there are arising concerns of consumer rights and safety due to humidifier fungicides and urethane track incidents, there are elements to be further researched on rigid polyurethane foam insulation for refregerated containers. Thus, we reviewed the prior standards for rigid polyurethane foam insulation and verified the validity of certification testing method for the new standard with self-foamed polyurethane.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.57-64
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• 2013

Objectives: Skin exposure to diisocyanates may be an important risk factor for respiratory sensitization to leading asthma. However little is known about the extent of worker's diisocyanates skin exposure and the effectiveness of personal protective equipments in polyurethane foam manufacturing companies. This study provides data on diisocyanates skin exposure, surface diisiocyantes contamination of foams and the effectiveness of personal protective gloves in five polyurethane foam manufacturing companies. Materials and methods Colorimetric SWYPE pads are used for the determination of diisocyanates on surfaces of workers skin and polyurethanes foams. Results: The forearms, necks and faces of workers in polyurethane foam manufacturing companies were found to be contaminated with diisocyanates. Heavy contamination with uncured diisocyanates at large block foams surfaces were found. Personal gloves of workers for skin protection showed significant penetrations by diisocyanates. Conclusions: We found that all workers in polyurethane foam manufacturing companies could be exposed to diisocyanates by skin exposure. Also further researches which would better quantify skin exposure are needed.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.4
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• pp.291-297
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• 2019

Polyurethane foam is the most efficient, high-performance insulation material, used for liquefied natural gas carrier (LNGC) insulation. Because LNGC is exposed to sloshing impact load due to ship motion of 6 degrees of freedom, polyurethane foam should be sufficient dynamic properties. The dynamic properties of these polyurethane foam depends on temperature and density. Therefore, this study investigates the dynamic response of polyurethane foam for various temperature($25^{\circ}C$, $-70^{\circ}C$, $-163^{\circ}C$) and density($90kg/m^3$, $113kg/m^3$, $134kg/m^3$, $150kg/m^3$) under drop impact test with impact energy of 20J, 50J, and 80J. For dynamic response was evaluated in terms of peak force, peak displacement, absorb energy, and the mechanical property with minimized density effects. The results show the effect of temperature and density on the polyurethane foam material for the dynamic response.