• Journal of the Korean Society of Tobacco Science
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• v.23 no.1
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• pp.12-18
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• 2001

This study was conducted to investigate the effect of tobacco curing on far infrared light on the quality of flue-cured tobacco leaves. Physicochemical characteristics such as alkaloid, total sugar, total nitrogen, starch, total phenolic compounds, browning degrees, and color differences, in cured tobacco leaves were compared between hot air and far infrared curing methods. There was no significant difference in sugar/nicotine ratio and nitrogen number between the curing methods, while the contents of ether extract and filling capacity were increase by far infrared curing. Therefore, it was expected that far infrared curing might be effective for high aroma and physical properties of the cured tobacco leaves.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.183-188
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• 2009

RFID method is a non-contact automatic identification technology, which attaches microchips and antennas to an object in a tag form, to send and process information sent to the network using wireless frequency. Drying and curing process is extremely important which minimizes the resistivity of RFID antennas. This research is about the drying characteristic of conductivity ink, and analyzes and compares the hot-air drying process and infrared drying process. Also, the research was done for the improvement in drying performance by using combined process of hot-air and infrared mechanism. The experiment result shows that the hot-air or infrared drying system used alone cannot meet the required performance in drying printing method using conductivity ink. The combined drying system of hot-air and infrared ray showed resistance low enough in short drying and curing time, and this mechanism makes drying and curing process for mass and continuous production possible on-line.

• Elastomers and Composites
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• v.43 no.1
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• pp.1-7
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• 2008

Far-infrared vulcanization of ethylene-propylene-diene terpolymer(EPDM) compounds has been studied in comparison with hot air vulcanization. Vulcanization characteristics of EPDM compounds were measured by degree of curing and temperature of specimens in vulcanization process. As a result, degree of curing by far-infrared of EPDM compounds was shown to be higher value than that by hot air at the same vulcanization temperature. Especially, degree of curing by far-infrared on 3 mm thickness of EPDM compounds was increased by two times compared to that by hot air. While the increase of thermal conductivity of EPDM compounds highly improved degree of curing by far-infrared, that hardly improved degree of curing by hot air.

• Journal of Technologic Dentistry
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• v.42 no.2
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• pp.65-71
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• 2020

Purpose: To know the transmittance of light when wearing shading goggles and to protect eyes from blue light emitted from dental scanner when using CAD/CAM works or inducing polymerization reactions of dental resin with curing unit and infrared light occurred when melting Dental precious metal and non-precious metal alloys. Methods: By measuring and comparing the average transmittances of blue light, visible light and infrared ight by using UV-Vis Spectrophotometer analysis measuring instrument, I compared 3 GREEN Color Goggles worn when casting Dental precious metal and non-precious metal alloys, and compared each of YELLOW, ORANGE Color Goggles worn when using Dental CAD/CAM scanners and Light Curing(LED) the Dental resin. Results: In blue light range, YELLOW Color Goggles are more effective than ORANGE Color Goggles. In infrared light range, No.12 Goggles are more effective than No.10 and No.11 Goggles. Conclusion: When wearing blue light shading goggles to avoid harmful blue light occurred in using dental scanner and curing light, and when wearing infrared light shading goggles to avoid harmful infrared light during casting, to avoid the Side Effects like transmittance rate of blue light and infrared light goggles becomes too high to block appropriate amount of harmful light or too low that causing lower image clarity.

• Polymer(Korea)
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• v.35 no.2
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• pp.141-145
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• 2011

The electron beam (EB) induced curing of a typical resin designed for the hard coating layer of in-mold decoration foils was investigated. The samples were irradiated with different doses of EB and the curing reaction was monitored by Fourier transform infrared (FTIR) spectroscopy. The change in coating properties such as surface hardness and anti-abrasion property was studied as a function of increasing dose. The effect of the addition of nano-particles on the improvement of coating properties was also examined. It was expected that the experimental results could be used for the commercial exploitation of the EB curing system comparable to the ultraviolet (UV) curing system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.10
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• pp.844-848
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• 2012

Encapsulant curing in terms of convection oven leads to thermal induced stress due to nonuniform thermal conductivity in LED package. We have adopted infrared (IR) light for silicone curing in order to release the stress. The light uniformity irradiated on an encapsulant surface is confirmed to be uniform by optical simulation. Shear strength of die paste using IR compared to convection oven is increased 19.2% at the same curing time, which indicates curing time can be shortened. The indentation depth difference between center and edge of silicone encapsulant in terms of convection oven and IR are 14.8% and 3.4%, respectively. Curing by IR also shows 2.3% better radiant flux persistency rate of LED at $85^{\circ}C$ after 1,000 h reliability test compared to convection curing.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.273-279
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• 2004

Recently, newly developed single high-intensity LED curing lights for composite resins are claimed to have a higher intensity than previous LED curing lights and to results in optimal properties and short curing time. The purpose of this study was to determine the curing effectiveness of the curing units and to evaluate the relationship between the degree of polymerization and distance from curing light tip end to resin surface. One composite resin was tested(Filtek Z250). Thin film specimens were cured with a LED curing unit(Elipar Freelight 2, 10s), Plasma Arc curing unit(Flipo, 6s), Halogen curing light(XL3000, 20s) at four curing light tip to the resin surface(0mm, 2mm, 4mm, 6mm). Degree of conversion of composite resins were determined by a Fourier Transform Infrared Spectrometer(FTIR). From the present study, the following results were obtained. 1. In all curing units, relative light intensity was significantly decreased according to the increase of distance of light tip to the resin surface(p<0.05). LED curing units showed a higher percentile decrease in intensity than other curing units. 2. In all curing units, degree of conversion was decreased as increase of the distance but no statistically significant difference(p>0.05) except between 4mm and 6mm(p<0.05). 3. When comparing degree of conversion of light curing units at each distance(0mm, 2mm, 4mm, 6mm), LED curing light had a higher degree of conversion than plasma arc and halogen curing lights at 0, 2, 4mm(p<0.05). At 6mm, there was a no significant difference among the curing units(p>0.05).

• Polymer(Korea)
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• v.26 no.1
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• pp.80-87
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• 2002

A comparative study using electron-beam(EB) and thermal curing techniques was carried out to determine the effect of cure behavior and thermal stability of epoxy resins. In this work, benzylquinoxalinium hexafluoroantimonate(BQH) was used as a latent cationic catalyst for an epoxy resin. According to the thermogravimetric analysis(TGA), the decomposed activation energy based on Coats-Redfern method was higher in the case of thermal curing technique. This could be interpreted in terms of slow thermal diffusion rate resulted from high crosslink density of the thermally cured epoxy resin. However, the increase of hydroxyl group in the epoxy resin cured by EB technique was observed in near-infrared spectroscopy(NIRS) measurements, resulting in improving the stable short aromatic chain structure, integral procedural decomposition temperature, and finally ductile properties for high impact strengths.

• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.464-470
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• 2013

PURPOSE. The aim of this Fourier transform infrared (FTIR) spectroscopic study was to measure the degree of conversion (DC) of dual-cured resin cements light-irradiated through zirconia ceramic disks with different thicknesses using various light-curing methods. MATERIALS AND METHODS. Zirconia ceramic disks (KT12) with three different thicknesses (1.0, 2.0, and 4.0 mm) were prepared. The light transmittance of the disks was measured using ultraviolet visible near-infrared spectroscopy. Four different light-curing protocols were used by combining two curing light modes (Elipar TriLight (standard mode) and bluephase G2 (high power mode)) with light-exposure times of 40 and 120 seconds. The DCs of the two dual-cured resin cements (Duo-Link and Panavia F2.0) light-irradiated through the disks was analyzed at three time intervals (3, 7, and 10 minutes) by FTIR spectroscopy. The data was analyzed using repeated measures ANOVA (${\alpha}$=.05).Two-way ANOVA and Tukey post hoc test were used to analyze the 10 minute DC results. RESULTS. The 1.0 mm thick disk exhibited low light transmittance (<25%), and the transmittance decreased considerably with increasing disk thickness. All groups exhibited significantly higher 10 minute DC values than the 3 or 7 minute values (P<.05), but some exceptions were observed in Duo-Link. Two-way ANOVA revealed that the influence of the zirconia disk thickness on the 10 minute DC was dependent on the light-curing methods (P<.001). This finding was still valid even at 4.0 mm thickness, where substantial light attenuation took place. CONCLUSION. The curing of the dual-cured resin cements was affected significantly by the light-curing technique, even though the additional chemical polymerization mechanism worked effectively.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.35-60
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• 1997

Physical properties of composite resins such as strength, resistance to wear, discoloration, etc, depend on the degree of conversion of the resin components. The clinical behavior of restorative resins varies brand to brand. Part of this variation is associated with the filler and differences in the polymer matrix. The polymer matrix of resins may differ because the involved monomers are dissimilar and because of variation in the catalyst system. The purpose of this study was to evaluate the degree of conversion of the composite resins according to the depth of cure and light curing time. 7mm diameter cylindrical aluminum molds were filled with each of five different hybrid light curing composite resins(Z-100, Charisma, Herculite XRV, Prisma TPH, Veridonfil) on the thin resin films. The molds were 1mm, 2mm, 3mm, 4mm, and 5mm in depth to produce resin films of various heights. Each sample was given 20sec, 40sec, and 60sec illumination with a light source. The degree of conversion of carbon double bonds to single bonds in the resin films was examined by means of Fourier Transform Infrared Spectrometer. The results were obtained as follows; 1. There was difference in the degree of conversion among five light curing composite resins according to the depth of cure for 20sec, 40sec, and 60sec illumination with light source with statistical significance(P<0.05). 2. Five light curing composite resins show lower degree of conversion at surface of the resin than depth of 1mm. 3. The degree of conversion of five light curing composite resins was siginificantly reduced from the maximum for the resin film when the light passed through as little as 1mm of each composite. 4. The degree of conversion of five light curing composite resins decrease significantly at the depth of 4mm, and polymerization was not occured at the depth of 5mm except for Prisma TPH. 5. The degree of conversion of five light curing composite resins was increased with increased light curing time, and there was no significant differences in the degree of conversion above 4mm in Z-100, 3mm in Charisma, and at depth of 5mm in Herculite XRV and Veridonfil(P>0.05).