Usporedba djelovanja različitih alkohola na fizikalno-kemijska svojstva otopine za vlaženje

master's thesis

• Author: Vesna Bašica
• Mentor: Miroslav Gojo (mentor)
• Committee member: Miroslav Gojo (član povjerenstva)
• Granter: University of Zagreb; Faculty of Graphic Arts; Zagreb
• Defense date and country: 2008-11-00, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Graphic Technology

Abstract

Zavisno o koncentraciji PAT u otopinama za vlaženje određivala su se njihova fizikalno-kemijska svojstva kao što su električna provodnost, pH vrijednost, napetost površine, te kontaktni kut na slobodnim površinama tiskovnih formi za ofsetni tisak s pozitivskim diazo kopirnim slojem.

Dobiveni rezultati ukazuju da otopine za vlaženje povećanjem volumnog udjela PAT smanjuje se električna provodnost i površinska napetost.

Proces vlaženja odvija se u blago kiselom mediju (pH vrijednost iznosi između 4.6 i 4.7, što ukazuje da su u otopinu dodane soli koje djeluju kao puferi. Dodatak PAT neznatno je povećava.

Kontaktni kut pri niskim koncentracijama 2-propanola u početku se povećava, da bi pri višim koncentracijama pokazao trend smanjenja. Pri visokim koncentracijama 2-propanola u otopinama za vlaženje kontaktni kut se značajno smanjuje.

Kontaktni kut bez obzira o kojoj se PAT radi značajno se smanjenjuje. Prema dobivenim rezultatima maksimalni volumni udio PAT-a ne bi trebao biti veći od 5 %.

Abstract (english)

Physicochemical properties such as electrical conductivity, pH value, surface tension and contact angle on the non-image areas of typographical forms for the offset print with positive diazo coating layer have been estimated depending on the concentration of Surface-Active Substanances in fountain solutions.

The obtained results show that increasing the volume part of the SAS in fountain solutions causes reduction of electrical conductivity and surface tension.

The dampening process occurs in mild acid medium (pH value is between 4.6 and 4.7) which shows that salts that act as buffers were added to the fountain solutions. Adding SAS non-significantly increases pH value.

Contact angle in the low concentration of 2-propanol initially increases, while at the higher concentration it indicates tendency of decreasing. At high concentration of 2-propanol in fountain solutions for dampening, contact angle is significantly decreased.

Contact angle is significantly decreased regardless of which type of SAS is used. According to obtained results, maximum volume of SAS should be no greater than 5 %.

• Keywords: Električna provodnost; kontaktni kut; napetost površine; ofsetne ploče; otopina za vlaženje; pH vrijednost površinski aktivne tvari (PAT)
• Keywords (english): Electrical conductivity; pH value; surface tension; contact angle; offset plates; fountain solution; surface active substances (SAS)
• Language: croatian
• URN:NBN: urn:nbn:hr:216:292451
• 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 10:35:17