• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.111-111
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• 2017

There still exist adhesives that have toxic compounds or consist of those materials in both our life and lots of industries. For instance, formaldehyde adhesive had been still used for woodworking and some medical adhesives had been considered as toxicity problems. In this situation, natural adhesives from raw materials have been suggested as an one of considerable interests. Natural adhesives in recent have been reported fabrication methods via biological materials such as proteins, celluloses, and starches. By-products derived from agricultural something have them richly and each has additional special properties. Using these properties to make natural adhesives, unique adhesives would be attained. In particular, rice-based adhesive is such a good example. Rice-based by-product adhesives have interestingly some pros pertaining to high adhesive strength, excellent water resistance and could dramatically be reduced a formaldehyde a harmful component of plywood. Hence, rice-based adhesive like glues could be applied to lots of industries including agricultural and biological technology. This review paper highlighted some recent development on natural adhesives as a promising biomaterial for agricultural and biological technology fields. The design of agricultural by-product-based natural adhesives were described to demonstrate the application of agricultural and biological technology

• Journal of Conservation Science
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• v.37 no.3
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• pp.282-288
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• 2021

This basic research was conducted to support the development of woodcraft bio-adhesives using peach gum, which is the resin produced by peach trees. The synthesis conditions of these adhesives were optimized by performing 144 experiments. The application potential of peach gum adhesives was explored by comparing their properties with those of three natural adhesives and four synthetic adhesives. The best adhesive strength was obtained by dissolving the resin in 80 mL of distilled water containing 1.5 g NaOH, 1.65 g H₂O₂ ( pH 8.0-9.0), 0.5 g NaClO, and 0.5 g H₂BO₂. The adhesive strength, which showed minimal changes and excellent reversibility, was 125.39 kgf/cm². Ultraviolet radiation-mediated deterioration in strength in the absence of total aerobic bacteria was negligible (△E^*ab = 2.75). These data confirm the potential value of peach gum-based bio-adhesives for woodcraft as well as their utility as alternatives for natural and synthetic adhesives used for the manufacture and restoration of handicrafts and preservation of cultural assets.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.217-220
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• 2009

Conductive adhesives have been investigated for use in microelectronics packaging as a lead-free solder substitute due to their advantages, such as low bonding temperature. However, high resistivity and poor mechanical behavior may be the limiting factors for the development of conductive adhesives. The metal fillers and the polymer resins provide electrical and mechanical interconnections between surface mount device components and a substrate. As metal fillers used in conductive adhesives, silver is the most commonly used due to its high conductivity and the stability. However the cost of conductive adhesives with silver fillers is much higher than usual lead-free solders and silver has poor electro-migration performance. So, copper can be a promising candidate for conductive filler metal due to its low resistivity and low cost, but oxidation causes this metal to lose its conductivity. In this study, electrically conductive adhesives (ECAs) using surface modified copper fillers were developed. Especially, in order to overcome the problem associated with the oxidation of copper, copper particles were coated with silver, and the silver-coated copper was tested as a filler metal. Especially the effect of silver coating on the electrical resistance just after curing and after aging was investigated. As a result, it was found that the electrical resistance of ECA with silver-coated copper filler was clearly lower and more stable than that of ECA with pure copper filler after curing process. And, during high temperature storage test, the degradation rate of electrical resistance for ECA with silver coated copper filler was quite slower than that for ECA with pure copper filler.

• Journal of Adhesion and Interface
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• v.17 no.2
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• pp.62-66
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• 2016

The curing processes of waterborne adhesives are in general undergone by using hot-air dryer. The hot-air dryer curing the adhesives with heat has a disadvantage of requiring high temperature over $100^{\circ}C$ as well as curing time as long as 20 min. When it comes to the heat control, high temperature open disturbs the adhesion of substrates by extremely lowering the viscosity of the adhesives. Furthermore, the humidity resulting from the drying process makes the curing condition irregularly. In this report, dehumidifying membrane dryer was used in order to keep the curing process same by removing humidity caused by the evaporation of water during the drying process, and to shorten the curing time. Here, we compared the peel strength of attached substrates in the dehumidifying membrane dryer to find out appropriate curing condition and confirm the effects of the dehumidifying membrane.

• Journal of Adhesion and Interface
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• v.8 no.1
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• pp.28-33
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• 2007

It is a main trend not to use organic solvents in the adhesive industry from the recent environmental and safe points of view. For example, water-based, hot-melt, or UV curable adhesives are being investigated. Several different kinds of tackifiers that are formulated in the adhesives in order to give them more functional properties like initial tack and higher adhesion, etc., have been proposed to meet the recent trend. Firstly, the characteristics and fundamental properties of the respective materials are presented. In Japan, the trend to develop the water-based adhesives is most remarkable. While the environmental regulations are getting harder, Arakawa Chemical has been spending a lot of energy for the research, and developed toluene-free and solvent free tackifier dispersions that are presented precisely.

• Steel and Composite Structures
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• v.20 no.3
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• pp.671-692
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• 2016

FRP stay-in-place (SIP) formworks are designed as a support for casting concrete and as a tension reinforcement when concrete is cured. Bond development between SIP formwork and concrete is critical for FRP tension element to be effective. This paper reports the bond strength between FRP formwork and concrete for different interfacial treatments. A novel experimental setup is prepared for observing the bond behaviour. Three different adhesives with varying workability have been investigated. Along with the load-deformation characteristics, bond slip and strains in the formwork have been measured. A finite element numerical simulation was conducted for the experiments to understand the underlying mechanism. The results show that the adhesive bonding has the best bond strength.

• Journal of Korean Society for Quality Management
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• v.42 no.4
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• pp.757-768
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• 2014

Purpose: In this paper we present a case study of developing fast curing adhesives for insulation material of LNG carriers using an extreme vertices design with four mixture components. Three material properties are considered - shear strength, viscosity, and tensile strength. In the optimization experiment, we used hardness instead of tensile strength due to shortage of specimens. Methods: We employ four-factor extreme vertices design with 19 runs and desirability function approach for simultaneously optimizing three responses. After selecting optimal condition of the mixture components, we do confirmation experiments to verify the reproducibility of the optimal condition under manufacturing circumstance. Results: Simultaneous optimal condition for the three responses, that is, shear strength, viscosity, and harness is obtained. At the optimal condition, confirmation experiments are executed in manufacturing circumstance. The variation for the shear strength is not satisfactory, which is due to the variation of the humidity. Conclusion: At the optimal condition three material properties are satisfactory. To reduce the variability for the shear strength, robust design is needed.

• The monthly packaging world
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• s.295
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• pp.55-59
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• 2017

• The monthly packaging world
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• s.315
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• pp.59-66
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• 2019

• Korea Science and Art Forum
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• v.37 no.5
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• pp.239-248
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• 2019

This study started from the need to improve one of shortcomings of synthetic PVAc adhesives - potential physical harm and environmental hazards to the workers or their users. As a matter of fact, PVAc adhesives are currently mainly used because of their convenience and economy for the production of woodcrafts. The purpose of this study was to develop natural adhesives through research on natural adhesives in step with the current increase of societal attention to environmental friendliness and rapid surge in their demand in the face of such problems. So, the study attempted research on the bases to develop natural adhesives for woodcraft, using cellulose extracts from wood - natural adhesive material. The findings of the study were as follows. Firstly, natural adhesives showed the improved effect in the field of adhesive strength, a basic physical property by 0.2 - 4 times compared with the existing materials and the study confirmed they had the similar or stable pH value. Besides, they had good reversibility, demonstrating their basic physical property as a natural adhesive for woodcraft. While, their durability to ultraviolet ray degradation also showed an excellent result value being better by 1.5 - 8.5 times than the existing materials. The study expects natural adhesives with improved and better performances compared with the existing materials could be developed, if further research on adhesive strength, antibiosis, conservative property were to continue by developing refinery technology for cellulose extracts from wood and rendering the functionality to them.