| Abstract | Koža je vrlo izdržljiv i otporan materijal, ali istodobno materijal koji je elastičan i diše; te ju odlikuje visoka čvrstoća, elastičnost, otpornost na abraziju, dobra propusnost zraka, mekoća i glatkoća. S obzirom na iznesena svojstva kože, ali i poznatu tehnologiju prerade kože od sirovog materijala do gotove dorađene kože i opterećenost primjenom velikih količina kemikalija i vode, te topline što negativno utječe na ekološki aspekt, u ovom radu je ispitana mogućnost primjene ekološki povoljne predobrade površine hladnom plazmom na poluprerađenoj (i jednom uzorku gotove kože) koži i potom primjena digitalnog inkjet tiska bez uporabe primera kao i poliuretanskih premaza za postizanje otisaka visokog stupnja kvalitete. Uzorci kromno i sintetski štavljene goveđe kože različitog stupnja dovršenosti s prirodnim licem su predobrađeni kisikovom i argonovom plazmom, nakon čega su podvrgnuti digitalnom inkjet pigmentnom tisku. Učinkovitost predobrade plazmom na postojanost digitalnog pigmentnog inkjet otiska karakterizirana je analizom površine FE-SEM mikroskopom, analiza pokrivenosti površine tiskom Dino-lite mikroskopom. Ispitan je i utjecaj predobrade na hidrofilnost/ hidrofobnost površine uzoraka primjenom jednostavnog testa kapi, postojanost otisaka na trljanje primjenom krokmetra, otpornost na savijanje metodom fleksometra, te je postojanost otiska na starenje u kontroliranim uvjetima ispitana primjenom ksenotesta. Analizom rezultata utvrđeno je da je površina uzoraka očišćena, te hrapavija s naglašenijim i otvorenijim ragadama i prisutnim granuliranim segmentima na licu kože. Ispitivanjem otpornosti otisaka na trljanje nisu dobiveni jednoznačni rezultati, te je teško zaključiti je li predobrada plazmom poboljšava ili ne postojanost otiska, ali su općenito bolji rezultati dobiveni kod transfer tiska u odnosu na direktni digitalni inkjet otisak. Prema dobivenim rezultatima ispitivanjem otpornosti na svijanje primjenom fleksometra pri 25 000 ciklusa gotovo svi uzorci su pokazali izvrsnu otpornost na svijanje kod gotovo svih uzoraka, kao i nakon izlaganja umjetnom svjetlu primjenom ksenotesta. Prema rezultatima nakon 75-satnog izlaganja (crvenog i plavog obojenja) nema značajnih promjena u izgledu otisnutih uzoraka, te iz rezultata proizlazi da uzorci tiskani metodom transfer tiska neovisno o vrsti štave i vrsti plina za predobradu plazmom imaju najviše ocjene (7/7), dok je samo kod obrade O2/Cr/D utvrđena najniža ocjena (1/6) u crvenom dijelu otisnutog uzorka. Takav rezultat može se pripisati razlijevanju pigmenta direktnog tiska po površini zbog nemogućnosti apliciranja primera. Uzorak gotov i dorađen (N/Cr-Crni/PD) otisnut direktnim tiskom uz primjenu primera pokazao je najveću ocjenu (7/7) koja je ujedno i najbolja ocjena za metodu direktnog tiska u usporedbi s transfer tiskom. |
| Abstract (english) | Leather is a very durable and resistant, but at the same time elastic and breathable material; it is characterized by high strength, elasticity, abrasion resistance, good air permeability, softness and suppleness. Considering the above-mentioned properties of leather, as well as the knowledge of the technology of processing leather from raw material to finished leather and the use of large amounts of chemicals and water, as well as heat, which negatively affects the ecological aspect, for this work on the semi-finished leather samples (and a sample of finished leather) the possibility of ecologically favorable pre-treatment of the surface with plasma and subsequent digital inkjet printing without the use of a primer, as well as polyurethane primers, is studied in order to obtain a high-quality print. Semi-finished samples of chrome and synthetically tanned cowhide of different finishing grades with natural surface are pretreated with oxygen and argon plasma and then subjected to digital inkjet pigment printing. The effectiveness of plasma pretreatment on the durability of digital pigment inkjet printing is characterized by surface analysis using a FE-SEM microscope and surface coverage analysis using a Dino-lite microscope. The effect of pretreatment on the hydrophilicity/hydrophobicity of the sample surface is also tested using a simple drop test, the frictional resistance of the print using a step gage, the flexural resistance using the flexometer method, and the aging resistance of the print under controlled conditions using the xenotest. When analyzing the results, it was found that the surface of the samples is cleaned, i.e. rougher, with accentuated and open grooves and the presence of granulated segments on the leather surface. No clear results were obtained when testing the frictional resistance of the print, so it is difficult to determine whether plasma pretreatment improves the resistance of the print or whether the results obtained with transfer printing are generally better than those obtained with direct digital inkjet printing. According to the results obtained when testing flexibility resistance with a flexometer at 25,000 cycles, almost all samples showed excellent flexibility resistance, as well as after exposure to artificial light with Xenotest. According to the results after 75 hours of exposure (red and blue color), there are no significant changes in the appearance of the printed samples, which means that the samples printed with the transfer printing process, regardless of the type of ink and the type of gas after plasma pretreatment, have the highest values (7/7), while only the O2/Cr/D process has the lowest value (1/6) for the red color of the printed sample. This result is due to the spreading of the pigment of the direct printing on the surface, since it was not possible to apply the primer. The finished sample (N/Cr-Crni/ PD) printed by the direct printing process with primer has the highest score (7/7), which is also the best score for the direct printing process compared to transfer printing. |
| Study programme | Title: Textile Technology and Engineering; specializations in: Clothing Engineering, Textile Design and Management, Industrial Textile Design, Industrial Clothing Design, Textile Chemistry, Materials and Ecology, Textile Chemistry, Materials and Ecology
Course: Textile Chemistry
Study programme type: university
Study level: graduate
Academic / professional title: magistar/magistra inženjer/inženjerka tekstilne tehnologije i inženjerstva (magistar/magistra inženjer/inženjerka tekstilne tehnologije i inženjerstva) |
