Sinđić, Igor (2015) Karakteristike ink jet otisaka izloženih kontroliranim utjecajima vanjske atmosfere = Characteristics of Inkjet prints exposed to controlled influences of outdoor atmosphere. Dissertation (PhD) thesis. Grafički fakultet. [Mentor: Bolanča, Zdenka].
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Abstract
Jedna od primjena ink jet tehnologije je tisak velikih formata npr. plakata i sličnih proizvoda, koji se izlažu na otvorenom u duljem vremenskom periodu. Da bi se zadržala postojanost i trajnost otisaka kao i uvažile postavke ekološke održivosti kroz životni ciklus tog proizvoda važno je razumjeti mehanizam starenja i utjecaj bitnih čimbenika. Mehanizam starenja uključuje brojne interakcije između podloge/bojila i njihovog okoliša, te su vidljive kao gubitak kemijske stabilnosti i smanjenje optičkih karakteristika. Osim toga kod izlaganja otisaka na otvorenom u duljem vremenskom periodu značajni su: sunčevo zračenje, zagađivala u zraku i nadmorska visina, atmosferska vlaga, oborine, vjetar i geografski položaj. U ovom radu prikazuju se rezultati studije utjecaja vrste tiskovne podloge, tehnologije ink jet tiska (termalni i piezo-električni), vrste bojila ( tekuće bojilo (dye), pigmentno i UV sušeće bojilo, meteoroloških čimbenika (temperatura i vlaga zraka, globalno i difuzno zračenje) i godišnje doba na postojanost i trajnost podloge i otisaka. Utjecaj zagađivala atmosfere na postojanost i trajnost prati se u realnim uvjetima, ali i izlaganjem otisaka poznatim koncentracijama NO2 i O3 u laboratorijskim uvjetima. Praćenje čimbenika i studiranje zakonitosti vezane su uz pojmove postojanosti i trajnosti otisaka i podloge, a koriste se optičke i kolorimetrijske metode. Da bi se postigla kompleksnost pristupa spomenute veličine upotpunjuju se u kombinaciji s podacima promjene 3D gamuta i 2D gamuta karakterističnih presjeka L*80, L*50 i L*20 obuhvaćajući dinamiku izlaganja otisaka i podloge stvarnim vanjskim uvjetima tijekom zime i ljeta, ali i ubrzanom starenju u laboratorijskim uvjetima. U istraživanjima je utvrđen udio endogenih i egzogenih čimbenika odgovoran za promjene u optičkim i kolorimetrijskim karakteristikama podloge. Rezultati se tumače nestabilnošću organske tvari u odnosu na povećanje koncentracije oksidansa u atmosferi, ali i globalnog zračenja, što može djelovati na oksidacijsku razgradnju nisko molekularnog dijela ugljikohidrata pri čemu nastaju karboksilne kiseline. Utvrđene su promjene kromatskih vrijednosti a* i b* koje nastaju degradacijom komponenti podloge. Dokazana je veličina promjene ΔE* za otiske sa 100% i 50% RTV za CMYK bojila izlaganih realnim vanjskim uvjetima, a rezultati se pojašnjavaju kroz promjene na odgovarajućim kromoforima, u funkciji temperature i vlage zraka, globalnog i difuznog zračenja, te koncentraciji O3 i NO2 u vanjskoj atmosferi. Na otiscima dobivenim piezo-električnom tehnologijom i pigmentnim bojilima izlaganjem vanjskim uvjetima zimi utvrđeno je smanjenje volumena gamuta, koje je u ljetnim mjesecima još intenzivnije. Dokazano je da kod ovih otisaka na vršnom presjeku gamutnog tijela, gamut se ne uočava. Kod otisaka s istom ink jet tehnologijom uz primjenu UV sušećih bojila izloženih vanjskim uvjetima volumen gamuta u odnosu na dinamiku izlaganja ima suprotan trend u usporedbi s otiscima iste tehnologije ali s pigmentnim bojilima. Pojava se tumači kroz mehanizam sušenja bojila i ulogu fotoinicijatora. Za tumačenje stabilnosti otisaka pri vanjskom izlaganju osim meteoroloških čimbenika u obzir se uzima geografski položaj i nadmorska visina. Rezultati dobiveni izlaganjem stvarnim vanjskim uvjetima i xenon arc metodom pojašnjavaju se u odnosu na kinetiku procesa i uvjete okoliša.
| Item Type: | Dissertation (PhD) thesis |
|---|---|
| Mentor name: | Bolanča, Zdenka |
| Thesis Committee: | Majnarić, Igor and Knešaurek, Nina and Mrvac, Nikola and Bolanča Mirković, Ivana and Osterman Parac, Đurđica and Banić, Dubravko and Milković, Marin |
| Defence date: | 30 June 2015 |
| Abstract in english: | One of the applications of ink-jet technology is wide format printing, for example posters or other similar products that are exposed to real outdoor conditions for a prolonged period of time. To keep the durability and permanence of the prints as well as to keep them environmentally sustainable throughout the life cycle of the product, it is necessary to understand the ageing mechanism and the influence of the important factors. The ageing mechanism includes various interactions between the substrate/ink and their environment, which are visible as a loss of chemical stability and reduction of optical characteristics. Significant factors influencing the prints exposed outdoors for an extended period of time include: the Sun radiation, air pollutants, altitude, atmospheric moisture, precipitation, wind and the geographical location. This paper shows the results of studying the effects of different printing substrates, ink-jet technologies (thermal and piezo-electrical), ink types (dye based ink, pigment based ink and UV curable ink), meteorological factors (temperature, humidity, global and diffusion radiation), and the season on the durability and permanence of the substrate and prints. The effect of air pollutants on durability and permanence was monitored in real outdoor conditions, but also with the exposure of prints to the known concentrations of NO2 and O3 in laboratory conditions. Optical and colorimetric methods were used to monitor the factors and study the laws regarding the terms of stability and permanence of the substrate and prints. To provide for the complexity of the approach, the aforementioned factors were accompanied with a combination of the 2D and 3D gamut data of characteristic sections L*80, L*50 and L*20, including the dynamics of the substrate and prints exposure to the outdoor conditions during winter and summer, along with the method of accelerated aging in laboratory conditions. The study undoubtedly showed that it is the share of endogenous and exogenous factors that is responsible for the changes in the optical and colorimetric characteristics of the paper. The results are interpreted as a consequence of the instability of the organic matter in the relation to an increase in the concentration of oxidants in the atmosphere as well as global radiation. This can affect the degradation of low molecular parts of the carbohydrates in the presence of oxygen, which in turn results in the formation of carboxylic acid. The changes of chromatic values a* and b* that result from the degradation of the components of the substrate were established. The change of ΔE* was proven for prints with 100 % and 50 % RTV for CMYK inks that were exposed to real outdoor conditions, and the results are explained through changes of the matching chromophores, in the function of temperature and humidity, global and diffusion radiation, and the concentration of O3 and NO2 in the outer atmosphere. As for the exposure of the prints obtained with piezo-electrical technology and pigment based inks during winter, it was established that the volume of gamut was reduced and that it is even more intense during summer. It was proven that with these prints on the top cut of the gamut, the gamut cannot be noticed. With the prints made with the same ink-jet technology, but with the UV curable inks compared with the same technology and pigment based inks when exposed to outdoor conditions, the gamut volume has an opposite trend. The appearance is interpreted with the drying mechanism of prints and the role of photoinitiators. When interpreting the stability of prints exposed to the elements, the geographical location and altitude should also be taken into account. The results obtained by exposure to real external conditions and xenon arc method are interpreted with respect to the kinetics of the process and environmental conditions |
| Uncontrolled Keywords: | ink-jet tisak, veliki formati, tekuće bojilo, pigmentno bojilo, UV sušeće bojilo, meteorološki čimbenici, zagađivala, atmosfere, ubrzano starenje |
| Keywords in english: | Ink-jet, wide format ink-jet prints, dye based ink, pigment based ink, ECO UV curable ink, meteorological parameter, air pollutant, accelerated ageing |
| Subjects: | TECHNICAL SCIENCES > Graphic Technology |
| Institution: | Grafički fakultet |
| City: | Zagreb |
| Number of Pages: | 301 |
| Callnumber: | 655.39:658.562 SIN d |
| Inventory number: | 10037 |
| Depositing User: | Antonia Grgurović |
| Status: | Unpublished |
| Date Deposited: | 28 Aug 2015 07:27 |
| Last Modified: | 28 Aug 2015 07:27 |
| URI: | http://eprints.grf.unizg.hr/id/eprint/2271 |
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