Usporedba djelovanja različitih koncentranata na proces vlaženja tiskovne forme

Brnadić, Ante (2009) Usporedba djelovanja različitih koncentranata na proces vlaženja tiskovne forme. Diploma work - Pre-Bologna programme. Grafički fakultet. [Mentor: Gojo, Miroslav].

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Abstract

Zavisno o vrsti i volumnom udjelu dodanog koncentrata pufera u otopinama za vlaženje određivala su se njihova fizikalno-kemijska svojstva kao što su pH vrijednost električna provodljivost te kontaktni kut na slobodnim površinama tiskovnih formi za plošni tisak s pozitivskim diazo kopirnim slojem. Dobiveni rezultati ukazuju da otopine za vlaženje povećanjem volumnog udjela PAT smanjuju električnu provodljivost. Vrijednosti se razlikuju u zavisnosti o uzorku pufera od kojij je pripremljena otopina za vlaženje. Proces vlaženja odvija se u blago kiselom mediju (pH vrijednost iznosi između 4.1 i 5.2, što ukazuje da su u otopinu dodane soli koje djeluju kao puferi. Zavisno o volumnom udjelu dodane PAT neznatno je povećava. Zavisno o volumnom udjelu dodane PAT, i uzorku pufera od kojih je pripremljena otopina za vlaženje, kontaktni kut se mijenja, te povećanjem volumnog udjela najprije se smanjuje do minimalne vrijednosti pri volumnim udjelima od oko 10%, a zatim neznatno raste. Jedino uzorak 2 pokazuje stalni porast kontaktnog kuta. Kontaktni kut, bez obzira o kojem se uzorku pufera radi, ima niske vrijednosti.

Item Type:	Diploma work - Pre-Bologna programme
Mentor name:	Gojo, Miroslav
Defence date:	December 2009
Abstract in english:	Physicochemical properties such as pH value, electrical conductivity and contact angle on the non-image areas of printing forms for the offset technique with positive diazo coating layer depending on the type and volume portion of added concentrate of Surface-Active Substances in fountain solutions have been estimated. The obtained results have shown that increasing of the volume portion of the SAS causes reduction of the electrical conductivity in fountain solutions. The values differ according to the type of added buffer. The fact that dampening process occurs in mild acid medium (pH value is between 4.1 and 5.2) confirms that salts which act as buffers have been added to the fountain solutions. Addition of the different volume portion of SAS has not significantly increased the pH value. Results have shown that contact angle values differ according to the type and volume portion of added buffer as well. As the measurements started contact angle values have been decreased with addition of volume portions of around10%. In addition, as the volume portion has been increased the contact angle values have been slightly increased too. Continuous increment has been measured solely on sample No. 2. Measurement of contact angle has shown low values regardless of which type of buffer is used.
Uncontrolled Keywords:	Električna provodljivostost, kontaktni kut, ofsetne ploče, otopina za vlaženje, pH vrijednost površinski aktivne tvari (PAT)
Keywords in english:	Electrical conductivity, contact angle, fountain solutions, offset printing forms, pH value, Surface-Active Substances (SAS)
Subjects:	TECHNICAL SCIENCES > Graphic Technology
Institution:	Grafički fakultet
City:	Zagreb
Number of Pages:	31
Callnumber:	goj 2009 brn
Inventory number:	D777
Status:	Unpublished
Date Deposited:	15 Nov 2013 21:36
Last Modified:	19 May 2014 12:39
URI:	http://eprints.grf.unizg.hr/id/eprint/751

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