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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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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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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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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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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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Světlostálost povrchových úprav barevnými laky
Rašovská, Karolína
This bachelor thesis deals with the determination of the light fastness of surface treatments with colored varnishes intended for the exterior. The color change was measured and analyzed on samples with a surface treatment of colored varnishes, namely on massive base materials of spruce and oak. The light fastness of the surface treatments of the verified paints was determined using the BYK spectrophotometer. The gloss change of the paints was assessed thanks to the PICOGLOSS 503 gloss meter. Tests of adhesion, paint thickness and hardness were also performed. To verify the properties of individual paints, the samples were subjected to tests according to ČSN standards. The aim of this work is to compare the properties of the used paints.
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Posouzení kvality dýhových sesazenek upravených tiskem
Kollarová, Eva
The main aim was to discover how the print will act if used as a finish treatment of furniture element by testing according to Czech standards. This thesis in theoretical part deals with fine face veneer manufacturing, demands on input raw material, describes procedures and technologies used in veneer manufacturing process. Then, it deals with spliced veneer problematics, especially factors which influence their quality. There is a brief overview of the worldwide production of veneers during years 2007 – 2017, also of import and export of veneer sheets to / from Czech Republic. In practical part, there were carried out tests of surface finish treatments according to chosen Czech standards, which were then analysed in accordance to ČSN 91 0102. Used samples were veneered, treated by oil – wax finishing and then printed. One of the tests was resistance to light – realized in climatic chamber for artificial aging (3 variants – each for 250 hours; first to simulate exterior conditions, second interior conditions and third interior conditions with high humidity). The requirements of the standard were not met in test of resistance to wet heat (change grade 3) and in case of resistance of light – almost all colours (except white and black) had greater value of total colour difference ΔE* than required in standard – more than 3,4 ± 0,4.
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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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