Utjecaj sastava razvijača na svojstva površine tiskovne forme za plošni tisak

master's thesis

• Author: Katarina Mihovilović
• Mentor: Miroslav Gojo (mentor)
• Committee member: Miroslav Gojo (član povjerenstva)
• Granter: University of Zagreb; Faculty of Graphic Arts; Zagreb
• Defense date and country: 2010-03, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Graphic Technology

Abstract

Zavisno o koncentraciji razvijača određivani su kontaktni kut, te slobodna površinska energija (SPE) na tiskovnim elementima i slobodnim površinama tiskovnih formi za ofsetni tisak. Kao razvijač upotrebljena je vodena otopina NaOH različitih koncentracija, a kao standardi za mjerenje kontaktnog kuta i SPE korišteni su dijodometan, voda i glicerol. Dobiveni rezultati ukazuju da povećanjem koncentracije razvijača dolazi do otapanja kako tiskovnih, tako i slobodnih površina tiskovne forme. Zavisno o upotrijebljenom standardu kontaktni kut na tiskovnim elementima se uglavnom smanjuje povećanjem koncentracije razvijača zbog otapanja kopirnog sloja i povećanja polarnosti površine. Na slobodnim površinama kontaktni kut se smanjuje korištenjem standarda čija je disperzna faza veća nego polarna (dijodometan, glicerol), dok voda kao standard ima veći udio polarne faze, te pokazuje porast vrijednosti kontaktnog kuta uzrokovano smanjenjem specifične površine, a time i manjom količinom adsorbiranih molekula vode. Slobodna površinska energija na tiskovnim elementima zavisi o koncentraciji razvijača, naime povećanjem koncentracije ukupna i disperzna slobodna površinska energija raste. Uzrok tomu može biti povećanje udjela polarne površine nastale otapanjem kopirnog sloja. Otapanjem slobodnih površina dolazi do smanjenja specifične površine, te dolazi do laganog porasta polarne faze. Na slobodnim površinama tiskovne forme dolazi do smanjenja ukupne slobodne površinske energije, kao i disperznog i polarnog udjela slobodne površinske energije. To može biti uzrokovano promjenom specifične površine, kao i promjenom polariteta same površine.

Abstract (english)

Depending on the concentration of developers, contact angle and surface free energy (SFE) are determined on non-image and image areas of printing plates for offset printing. As a developer is used a water solution of different concentrations of NaOH, and as standards for measuring the contact angle and SFE were used diiodomethane, water and glycerol. The results obtained indicate that increasing concentrations of developers causes melting image and non-image areas of printing forms, as well. Depending on the used standard, contact angles on the image areas are generally reduced by increasing the concentration of the developer as a result of melting coating layer and increaseing the polarity of the surface. At the non-image areas contact angle is reduced by using standards whose dispersed phase is greater than the polar (diodometan, glycerol) while water as a standard has a higher proportion of polar phase, showing the increase in the value of contact angle due to a reduction of specific surface area and thus a small amount of adsorbed molecules of water . Surface free energy of the image areas depends on the concentration of developers, namely increasing the concentration total and dispersed surface free energy increases. Cause of that may be increasing the share of the polar surface caused by dissolving coating layer. Dissolving the non-image areas leads to reduction of specific surface and leads to slow growth in the polar phase. On the non-image areas of printing plates occurs to reduce the total free surface energy, as well as share dispersed and polar surface free energy. This may be caused by changing the specific surface area, as well as changing the polarity of the surface.

• Keywords: kontaktni kut; razvijanje; slobodna površinska energija; tiskovna forma
• Keywords (english): Contact angle; developer; free surface energy; printing plate
• Language: croatian
• URN:NBN: urn:nbn:hr:216:544178
• 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: 2024-04-17 09:57:57