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Lightfastness of digital color prints
Kulhánková, Michaela ; Jančovičová, Viera (referee) ; Dzik, Petr (advisor)
In this diploma thesis the current methods of color fastness evaluation of color digital prints were solved. The theoretical part provides basic information needed to understand the experiment. Samples of inkjet prints were subjected to accelerated and long-term lightfastness test. The long-term test took place in the spaces of the Faculty of Chemistry, Brno University of Technology, which fulfilled the condition of direct light in a closed room. For one year, samples were exposed and their reflection spectra were measured at monthly intervals. An accelerated lightfastness test was performed in a solar chamber with a xenon lamp. Only some samples were selected for this test because of the small space in the chambre and thw failure of the instrument. At regular intervals were measured again their reflection spectra from which the colorimetric values were calculated. After completion of the testing, the rate parameter was determined from the dependence of the loss of the normalized gamut volume on different doses of irradiation. In the case of long-term testing, it was based on data from the Hydrometeorological Institute, which gave values of direct outdoor solar radiation. In the accelerated test, the irradiation dose of the sample up to 800 nm was determined. Finally, the lightfastness of each sample was examined and compared with each other and the relevance of the accelerated test was assessed.
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Accelerated testing of lightfastness of indoor furniture coatings
Kulhánková, Michaela ; Drábková, Klára (referee) ; Dzik, Petr (advisor)
This bachelor thesis deals with the study of the current methods of testing and evaluation of lightfastness of interior paints. Their fading is caused mainly by the influence of solar radiation. The first part provides the basic information needed to understand the experiment. In the second part, wood samples with various white varnishes and coatings were subjected to accelerated testing of lightfastness. The experiment was performed by exposing these samples to xenon lamp through the window glass filter in the solar chamber. Changes in the color of the samples were evaluated based on the measurement of the reflection spectra from which the colorimetric quantities were calculated and then displayed in the color space CIE 1976 L*a*b*. The conclusion was focused on the final real life of the samples, their mutual comparison and evaluation of the most suitable materials.
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Svetlostálosť morených povrchových úprav
Machunková, Andrea
This bachelor thesis deals with the influence of artificial UV radiation on plywood samples made of chosen woods - oak (Quercus), alder (Almus) and ash (Fraxinus) and examines the influence of surface conditioning on light permanency of wood surface. Samples were stained by water-soluble and solvent stains and finished by water-soluble and solvent lacquers. Samples were examined by standardized tests in the laboratory. We have determined the influence of type of stains on the speed of drying times and hardness and roughness of the coatings and evaluated changes in color depending on the surface conditioning.
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Srovnání tenkovrstvých lazur, silnovrstvých lazur a krémových lazur pro dokončování venkovního nábytku
Vrabček, Tomáš
In this bachelor thesis is solved the application of suitable surface finish of outdoor furniture made from solid oak and larch. There are compared three kinds of solvent-born semi-transparent wood stain with various characteristics. There were used low-build semi-transparent stain, high-build semi-transparent stain and semi-transparent stain of cream consistency. Physical-mechanical properties of the surface are evaluated depending on weathering (humidity, sunlight, temperature). There are give comparison of changes by the world side and changes of unexposed samples that were saved in a box and packed in the black foil without access of air and sunlight. This thesis is supported by laboratory measurements during the exposure period which was 4 months.
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Enhancement of print lightfastness by varnishing and lamination
Komárková, Hana ; Reháková, Milena (referee) ; Dzik, Petr (advisor)
This diploma thesis deals with recent methods of lightfastness evaluation of both classic and digitally printed photographs. It summarizes the experimental methods used for colour change measurements. Primarily, it studies an influence of additional protection on lightfastness enhancement. Lightfastness testing of colour prints was carried out by accelerated ageing. Samples were prepared by 3 types of inkjet printers and 3 different print media. The surface of photographs was left untreated or modified by varnishing or lamination. A set of samples, thus achieved, was used to monitor a print behaviour during the light exposure. In conclusion effects of used receiving layer, ink or additional surface treatment were discussed. Colour changes were evaluated on the basis of measured reflectance spectra from which colorimetric quantities were calculated. Results were processed using VolGa application. An actual print-life was calculated from the plot of the normalized gamut volume loss and the exposure.
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A study on the Lightfastness of Color Prints
Štěpánková, Eva ; Reháková, Milena (referee) ; Dzik, Petr (advisor)
This paper gives a brief overview on the published and accepted standards and methods for colour photography and print lightfastness measuring and evaluating. A comparison of selected valid standards and evaluation suggestions has been made. Sample sets was produced by various photographic processes and printing techniques. Identical sample sets were used in both long-term and accelerated ageing experiment. In this thesis, the degradation speed is expressed as a formal rate constant, which was calculated from the dependence of normalized gamut volume on the exposure dose. Photographs and prints were compared on calculated lifetime basis. A failure of reciprocity law was observed, which indicates a lower credibility of estimated lifetime predictions based on accelerated ageing.
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Catalytic fading of inkjet prints
Brablc, Tomáš ; Havlínová,, Bohuslava (referee) ; Veselý, Michal (advisor)
This thesis deals with the principles of inkjet printing, ink composition, receiving layers and print fading. The fading usually does not take place only for one reason, it is affected by more factors at a time. The catalytic fading due to light is studied. The catalytic fading takes place in overprinted areas where are situated more then one ink. The experiment was realized by the exposure of overprinted fields in accelerated ageing test. Mutual influence of two dyes from CMY together and then influence of black dye (K) on these overprinted fields were observed.
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Methods of Color Prints Lightfastness Evaluation
Komárková, Hana ; Havlínová,, Bohuslava (referee) ; Dzik, Petr (advisor)
This bachelor thesis deals with recent methods of lightfastness evaluation of the colour photographs. It summarizes the experimental methods used for both classic and digitally printed materials. Samples made by using the dye diffusion thermal transfer were put to accelerated and long-term lightfastness tests. Colour changes of the samples were evaluated on the basis of measured reflective spectra from which colorimetric quantities were calculated. The velocity constant of photograph fading was specified by dependence on the loss of normalized gamut volume on the exposure.
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Povrchová úprava dřevěných fasád
Slováčková, Hana
This thesis deals with monitoring changes in surface finishing of spruce and larch wood in outdoors. Using outdoor weathering tests the properties of two kinds of paints were tested by - a thin glaze and oil paint, two shades from each. In this work, the influence of the composition of the paint on its durability and light fastness was examined. This issue is closely related to the resistance of coatings to weathering, including solar radiation (UVA and UVB), atmospheric oxygen, relative humidity, temperature, precipitation, biological attack, chemical impacts (air pollution, acid rain, etc.).
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Světlostálost povrchových úprav tropických druhů dřev
Parkan, Radim
The diploma thesis deals with the light permanency changes of some chosen tropical woods. Their trade names are garapa (Apuleia Leiocarpau), angelim (Hymenolobium Petraeum), meranti (Shorea spp), sapeli (Entandrophragma cylindricum), merbau (Intsia bijuga), massaranduba (Manikara), teak (Tectona grandis), iroko (Chlorophora excelsa) and eucalyptus (Eucalyptus grandis). The woods are surface modified by means of four different surface modifications both with and without a usage of an alcohol base. All samples were lighted up by artificial sunlight from the xenon lamp for 106 hours by lighting 209,7 KJ/m2. The colour changes were measured during the exposition according to the greyscale and spectrophotometer in the CIEL *a*b* color model. Then the individual woods' color changes depending on the surface modification were assessed by the color difference deltaE*.
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