Zember, Davor (2022) Utjecaj viskoznosti tiskarskih boja na kvalitetu otiska na tiskovnim podlogama s ne-drvnim vlakancima. Master's thesis - Graduate Programme. Grafički fakultet. [Mentor: Bates, Irena].
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Abstract
Viskoznost je svojstvo (plinova i tekućina) da se odupru strujanju ili relativnom gibanju susjednih slojeva. Viskoznost je vrsta unutarnjeg trenja tekućine. Kvantitativna mjera unutarnjeg trenja je koeficijent viskoznosti tekućine. Viskoznost ovisi o: strukturi tvari i temperaturi (značajno opada s porastom temperature). Viskoznost je trenje koje nastaje kada molekule tekućine pomiču svoje slojeve tijekom strujanja (deformacije) pod utjecajem odgovarajućeg naprezanja. Očituje se samo kada se tekućina kreće. To se događa kada se slojevi tekućine kreću različitim brzinama. Budući da tiskarske boje sadrže suspendirane pigmentne čestice, koje su poput plastike, imaju veliki utjecaj na mjerenje viskoznosti – relativne elastičnosti boje. To znači da se mora primijeniti određena sila kako bi metalni cilindar viskozimetra prevladao relativnu elastičnost boje prije nego što se cilindar aktivira. Sila potrebna da se prevlada relativna elastičnost (krutost) prevlake naziva se granica tečenja. Granica tečenja boje ovisi o količini pigmenta, veličini čestica i obliku pigmenta te stupnju njegove disperzije ili flokulacije u vezivu. Viskoznost gustih tiskarskih boja određuje se mjerenjem otpora metalne šipke kroz boju u jedinici vremena. Za rijetke tiskarske boje koristite jednostavan ručni viskozimetar, drugačija ispusna čašica s mlaznicom na dnu mjerne posude. Mjeri protok volumena boje u jedinici vremena kroz otvor definiranog promjera. Viskoznost tiskarskih boja također se može odrediti pomoću rotacijskog viskozimetra: mjerenjem otpora koji tekućina pruža rotaciji metalne osovine/vretena.
| Item Type: | Master's thesis - Graduate Programme |
|---|---|
| Mentor name: | Bates, Irena |
| Thesis Committee: | Plazonić, Ivana and Bates, Irena and Zjakić, Igor |
| Defence date: | 21 July 2022 |
| Abstract in english: | Viscosity is the property of gases and liquids to resist flow or relative motion of adjacent layers. Viscosity is a form of internal friction of a fluid. A quantitative measure of internal friction is the coefficient of viscosity of a liquid. Viscosity depends on the structure of the substance and the temperature (it decreases significantly with increasing temperature). Viscosity is the friction that occurs when liquid molecules move their layers during flow (deformation) under the influence of an appropriate stress. It occurs only when the fluid is in motion. This happens when the liquid layers move at different speeds. Since printing inks contain suspended pigment particles, which are like plastic, they have a great influence on the measurement of viscosity - the relative elasticity of the ink. This means that a certain force must be applied for the metal cylinder of the viscometer to overcome the relative elasticity of the ink before the cylinder is activated. The force required to overcome the relative elasticity (stiffness) of the coating is called the yield strength. The yield strength of ink depends on the amount of pigment, the particle size and shape of the pigment, and the degree to which it is dispersed or flocculated in the binder. The viscosity of dense printing inks is determined by measuring the resistance of a metal bar through the ink in a unit of time. For rare printing inks, a simple hand-held viscometer is used, a different discharge cup with a nozzle at the bottom of the measuring cup. It measures the flow of the ink volume in a unit of time through an orifice of a certain diameter. The viscosity of printing inks can also be determined with a rotational viscometer by measuring the resistance that the liquid offers to the rotation of the metal axis/spindle. |
| Uncontrolled Keywords: | boje, tehnike tiska, tiskovne podloge s ne-drvnim vlakancima, viskoznost |
| Keywords in english: | viscosity, inks, non-wood fiber printing substrates, printing techniques |
| Subjects: | TECHNICAL SCIENCES > Graphic Technology |
| Institution: | Grafički fakultet |
| City: | Zagreb |
| Number of Pages: | 46 |
| Additional Information: | Ovaj rad izrađen je u okviru projekta „Otiskivanje, kvaliteta i uporabljivost podloga s ne-drvnim vlakancima“ UIP-2017-05-2573 financiranog sredstvima Hrvatske zaklade za znanost. |
| Callnumber: | BAT 2022 ZEM |
| Inventory number: | DB972 |
| Additional Information: | Ovaj rad izrađen je u okviru projekta „Otiskivanje, kvaliteta i uporabljivost podloga s ne-drvnim vlakancima“ UIP-2017-05-2573 financiranog sredstvima Hrvatske zaklade za znanost. |
| Depositing User: | Nina Jelača |
| Status: | Unpublished |
| Date Deposited: | 22 May 2023 09:02 |
| Last Modified: | 22 May 2023 09:02 |
| URI: | http://eprints.grf.unizg.hr/id/eprint/3468 |
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