• Journal of the Korean Wood Science and Technology
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• v.26 no.4
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• pp.92-97
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• 1998

Four urea-formaldehyde (UF) resins were synthesized as a particleboard (PB) binder with the four different initial formaldehyde/urea mole ratio and the final mole ratio of 1.15. The UF resins were characterized according to the standard method of resin adhesive analysis. PBs were manufactured using liquid UF resins at 5 minutes press time and 6% resin solids levels on an ovendry particle weight basis. A total of 20 PBs was fabricated for 5 panel replication per UF resin types. The panels were tested for physical strength properties per the procedure ASTM D 1037. The formaldehyde emission levels from the PBs bonded with the UF resins were tested according to 2-hour desiccator test method ASTM D 5582. There were no significant differences among UF resin types for internal bond strength of PBs. But there were significant differences among UF resin types for formaldehyde emission level of PBs. The results showed that the formaldehyde emission level was influenced by the UF resin types without reducing the adhesive performance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.1 no.1
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• pp.55-62
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• 2002

This investigation reports the grinding characteristics of titanium alloy(Ti-6AI-4V). Grinding experiments were performed at various grinding conditions. The grinding forces were measured to investigate the grindability of titanium alloy with the five different wheels including Green carbide, Alumina, Resin Diamond, Resin CBN and Vitrified CBN. To investigate the grinding characteristics of titanium alloy grinding force, force ratio, specific grinding energy and grinding-ratio were measured. Surface roughness was also measured with tracer and the ground surfaces were observed with SEM Residual stress measurement was conducted on the X-Ray Diffractometer. Force ratio of grinding of titanium alloy was very lower than that of grinding of SKD-11 Surface roughness with Resin Diamond wheel was a little larger and rougher surface than that with other wheels Grinding ratio of titanium alloy was a little lower than that of other materials. Grinding ratio of titanium alloy with Diamond wheel was almost six times larger than that With CBN wheel. As a result of five different wheels, the most excellent wheel in grinding of Titanium alloy was Resin Diamond wheel.

• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.437-441
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• 2017

This study was carried out to investigate the volumetric expansion ratio and hardness of expanded graphite after coating with various resins which were used as an additive of fireproof sealant. The coating thickness of the resin, which represents the coating rate, was dependent of the drying speed of the resin and the viscosity of the resin. Therefore the coating thickness was shown as follows: polyvinyl acetate > acrylic resin > urethane resin > water soluble latex. Furthermore, the volumetric expansion ratio was as follows: urethane resin > water soluble latex > acrylic resin > polyinyl acetate and the hardness was as follows: polyvinyl acetate resin > acrylic resin > water soluble latex > urethane resin. This showed that the volume of expansion was reduced by expansion, which was not covered by coating, but significantly increased by increasing hardness and allowed it to be used as a refractory addition. According to the response surface methodology, the optimized addition amount and stirring speed of acrylic resin were 37.6 wt% and 441.4 rpm, respectively.

• Journal of Korean Society of Forest Science
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• v.60 no.1
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• pp.37-44
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• 1983

Thermoplastic aceton-formaldehyde resin adhesive was added as a modifier for urea-formaldehyde resin adhesive and its effects on plywood smear strength and wood failure were investigated. The results are summarized as follows: 1) The plywood shear strength and wood failure showed the highest values at $120^{\circ}C$ of hot plate temperature, but the values decreased according to the rise of addition ratio of aceton resin. 2) The variation of molar ratio of aceton resin had no effect on plywood shear strength and wood failure. 3) The plywood bonded by the addition of aceton resin showed lower values than those of urea resin bonding plywoods in shear strength and wood failure. Therefore, aceton resin was inadequate as a modifier of urea resin adhesive.

• Journal of the Korean Wood Science and Technology
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• v.34 no.4
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• pp.31-36
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• 2006

This study was conducted to improve the bond strength of plywood bonded with F/U molar ratio urea-formaldehyde (UF) resins modified with the selected FGMDI prepolymer contents for various purposes. The amount of FGMDI was mixed with liquid UF resin at 0 wt% (as control), 2 wt%, 5 wt%, 10 wt%, 25 wt%, and 50 wt% based on the resin solids. As results, in bonding strength, plywood with F/U molar ratio of 1.4 showed the highest value in Type 2 test and all molar ratio UF resins modified with over 25 wt% of the FGMDI showed more than $11kgf/cm^2$, which was satisfied the minimum requirement of KS standard, $7.5kgf/cm^2$, after Type1.5 testing. As F/U molar ratio was increased and the FGMDI addition in the UF resin was increased, average reduction rate of Type 1.5 bonding strength compared with Type 2 was significantly decreased.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.92-99
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• 2016

Polyurethane resin used to leather coat was synthesized by the addition reaction of PPG and PTMG with different mole ratios. Physical characteristics of the synthesized polyurethane resin were measured by the SEM, FT-IR and the UTM. Increasing mole ratio of PTMG having four methylene groups caused the increase of abrasion resistance and tensile strength. The elongation was decreased. As we measured the solvent(toluene) resistance of poly urethane resin, it was found the there were no effect of PTMG mole ratios on the phyhsical properties of the resin. The viscosity was increased by ratio of PTMG mole ratio.

• Journal of the Korean Wood Science and Technology
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• v.21 no.1
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• pp.51-58
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• 1993

The phenol resorcinol formaldehyde resin (PRF) adhesives which are curing at ambient temperature for structural purposes were synthesized. A PRF resin is produced according to the two-stage reaction system. In first stage, a low-condensed resol or methylolated phenol were prepared from phenol by reaction with a formaldehyde in alkaline condition. The molar ratio of phenol to formaldehyde was 1.0~1.4. And in second-stage, resorcinol was added to combine with the methylol group of a low-condensed resol(R/P molar ratio 0.3). The glue-joint strength, pot-life and workability of this synthetic PRF resin were superior to conventional ambient temperature setting adhesives such as oilic urethane or water based polymer-isocyanate resin for wood adhesives.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.49-52
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• 2006

Epoxy resin has less reaction shrinkage, has better water proofing and thermal resistance than other repairing materials, to it has been applied broadly to repair and finish buildings and infrastructures. Although the ambient temperature constructed is varied with the seasons and epoxy resin has to mix with appropriate hardener due to the non self-hardening, as the real construction of it, the ambient temperature is ignored and the blending ration of epoxy resin and hardener is fixed. Also, because of the hardening time is aimed to temperature condition and the tolerance of blending ratio, we investigated the variation of viscosity according to ambient temperatures and hardener ratios. As a results of study, we can select the economical blending ratio of the epoxy resin and hardener according to site situation.

• Textile Coloration and Finishing
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• v.5 no.4
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• pp.79-91
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• 1993

The purpose of this study is to prepare the newer, more comfortable of urea-formaldehyde resin finished fabrics. The methods of this study are by making examinations and comparisons the relations between the thickness, fabrics counts, weight, moisture regain and crease recovery of cotton and viscose rayon fabrics caused by condition of urea-formaldehyde resin finishing and warm retaining ability and warm-cool sense. The analytic results of thermal character in state of fabrics material finished with urea-formaldehyde are as follows: 1. The warm retaining ability has no correlation with mixing ratio of resin but the increase of the warm retaining ability has correlation with the increase of concentration of urea-formaldehyde resin. 2. The result pf multiple regression analysis for effect of physical property according to the concentration of resin to the warm retaining ability revealed as below. As the weight, thickness and density increase and moisture regain decreases, the warm retaining ability increases. 3. The qmax value has no correlation with mixing ratio of resin but the increase of the qmax value has correlation with the increase of resin concentration. In the end, the effect of it promotes cool sense. 4. The result of multiple regression analysis for effect of physical property according to the concentration of resin to the qmax value revealed as below. As he weight and thickness increase, the qmax value decrease. But, as the density and crease recovery increase, the qmax value increase.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.337-341
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• 2001

A new method to extract gold from pyrite roster cinder, which combines ultra-fine-grinding with resin-in-pulp, has been studied in this paper. Compared with traditional leaching technology, it can short leaching time, avoid complex filter process, lower sodium cyanide consumption and increase gold recovery by 35%. During leaching, aluminium oxide ball was used as stirred medium, hydrogen peroxide as leaching aid and sodium hexametaphosphate as grinding aid. With the high efficiency and chemistry effect of ultra-fine-grinding, the leaching process was developed and the gold leaching rate may reach 88%. With AM-2 Б resin as abosorber and sulfocarbamide (TU) as eluent, gold was recovered from cyanide pulp by resin-in-pulp. AM-2 Б resin has good adsorbability in cyanide solution(pH=10). It was easy to elude gold from the loaded resin with 0.1㏖/L cholhydric acid and 1㏖/L sulfocabamide. The effect of contact time, temperature and acidity etc. on the gold absorption had been examined with static methods. The results showed that the adsorption and desorption of gold could both reach over 98%. The effects of flow rate of solution on dynamic adsorption and elution of gold had been examined with dynamic methods. Breakthrough curve and elution curve had been drawn in this paper. A mild condition was determined through a number of experiments: leaching time 2 hours, liquid solid ratio 4:1, sodium cyanide 3kg/t, hydrogen peroxide 0.05%, sodium hexametaphosphate 0.05%; adsorption time 30 minutes, temperature 10-3$0^{\circ}C$, resin($m\ell$) solid(g) ratio 1:10, eluent resin ratio 10-20:1, velocity of eluent $1.5m\ell$/min. Under the mild condition, the gold recovery may reach 85%.