Svojstva papirne podloge i njihov utjecaj na registar u višebojnom ofsetnom tisku

master's thesis

• Author: Karlo Ćorluka
• Mentor: Tomislav Cigula (mentor)
• Committee member: Igor Majnarić (predsjednik povjerenstva)
• Committee member: Tomislav Cigula (član povjerenstva)
• Committee member: Diana Milčić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Graphic Arts; Zagreb
• Defense date and country: 2023-07-21, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Graphic Technology

Abstract

Papir je higroskopni materijal te njegova primjena u klasičnom ofsetnom tisku stvara
dodatne izazove, pogotovo u višebojnom tisku. Promjena u dimenziji papira, uslijed
apsorpcije otopine za vlaženje, smanjuje kvalitetu otiska, a može utjecati na čitljivost
teksta i stvaranje moire efekta. Operateri za tiskarskim strojevima svojim intervencijama
smanjuju odstupanja u registru kako bi otisak ostao kvalitetan, no za to je potrebno znanje
i iskustvo. Cilj ovog rada bio je odrediti utjecaj svojstva papirne podloge na njeno
ponašanje u višebojnom tisku. Za istraživanje koriste se uzorci papira različitih
gramatura, tiskovni motivi koji imaju veći ili manji nanos boje te različiti smjer vlakanaca
u papiru. Korišteni uzorci tiskani su na Heidelberg XL-106-8-P tiskarskom stroju koji ima
mogućnost obostranog tiska u jednom prolazu. Boja, otopina za vlaženje, relativna
vlažnost i ostali parametri u procesu tiska ujednačeni su tijekom tiska svih papirnih
podloga. Papir je karakteriziran ispitivanjem površinskih svojstava, upojnosti te
mehaničkim svojstvima. Rezultati su pokazali da veća količina boje, strana
(prednja/stražnja) otiska kod nepremazanih i premazanih papira značajno utječu na
odstupanje u registru, također odstupanje u registru nije isto na svim pozicijama arka.
Premazani papiri imaju veću upojnost i prekidnu silu u odnosu na nepremazane, ali i
manji kontaktni kut s otopinom za vlaženje. Analizom korelacija odstupanja u registru i
karakteristike papira nije primijećena njihova međusobna povezanost. Eksperimentalni
dio ovog rada ukazao je na potrebe šireg spektra papirnih podloga te tisak većeg broja
uzoraka kako bi se dobio statistički značajniji rezultat.

Abstract (english)

Paper is a hygroscopic material, and its application in classic offset printing creates
additional challenges, especially in multi-color printing. The change in the size of the
paper, due to the absorption of the wetting solution, reduces the quality of the print, and
can affect the readability of the text and create a moiré effect. The operators behind the
printing machines reduce deviations in the register with their interventions if the print
would remain high-quality, but this requires knowledge and experience. The aim of this
work was to determine the influence of the properties of the paper substrate on its
behavior in multi-color printing. The research uses paper samples of different grammages,
printed motifs with greater or lesser color application and different direction of fibers in
the paper. The used samples were printed on a Heidelberg XL-106-8-P printing machine,
which has the possibility of double-sided printing in one pass. Color, wetting solution,
relative humidity and other parameters in the printing process are adjusted during the
printing of all paper substrates. The paper is characterized by testing its surface properties,
absorbency and mechanical properties. The results showed that a larger amount of paint,
the side (front/back) of the print in uncoated and coated papers significantly affects the
deviation in the register, also the deviation in the register is not the same in all positions
of the sheets. Coated papers have higher resistance and breaking force compared to
uncoated ones, but also a smaller contact angle with the wetting solution. By analyzing
the correlation of deviations in the register and paper characteristics, their mutual
connection was not observed. The experimental part of this work indicated the need for a
wider range of paper substrates and the printing of a larger number of samples in order to
obtain a statistically significant result.

• Keywords: papir; ofsetni tisak; višebojni tisak; registar
• Keywords (english): paper; offset printing; multicolor printing; register
• Language: croatian
• URN:NBN: urn:nbn:hr:216:050726
• Study programme: Title: Graphic technology; specializations in: Graphic technology, Design of graphic products; Course: Graphic technology; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra inženjer/inženjerka grafičke tehnologije (sveučilišni/a magistar/magistra inženjer/inženjerka grafičke tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2024-09-27 08:52:58