Abstract: Samples of tap and wastewater were collected in three offset printing facilities in Novi Sad, Serbia. Ten physicochemical parameters were analyzed within all collected samples: pH, conductivity, m - alkalinity, p - alkalinity, acidity, carbonate concentration, hydrogen carbonate concentration, active oxygen content, chloride concentration and total alkali content. All measurements were conducted using the standard analytical and instrumental methods. Comparing the obtained results for tap water and wastewater, a clear quality difference was noticeable, since all physicochemical parameters were significantly higher within wastewater samples. The study also involves the application of simple linear regression analysis on the obtained dataset. By using software package ORIGIN 5 the pH value was mutually correlated with other physicochemical parameters. Based on the obtained values of Pearson coefficient of determination a strong positive correlation between chloride concentration and pH (r = -0.943), as well as between acidity and pH (r = -0.855) was determined. In addition, statistically significant difference was obtained only between acidity and chloride concentration with pH values, since the values of parameter F (247.634 and 182.536) were higher than Fcritical (5.59). In this way, results of statistical analysis highlighted the most influential parameter of water contamination in offset printing, in the form of acidity and chloride concentration. The results showed that variable dependence could be represented by the general regression model: y = a0 + a1x+ k, which further resulted with matching graphic regressions.
Abstract: This research aimed to produce offset printing inks from Samut Songkram’s coconut oil and to test properties of the printing inks comparing with commercial offset printing inks. One of the ingredients in the process of mixing varnish is coconut oil – used to produce black offset printing inks which were the subject of testing issues in order to compare with commercial offset printing inks. Based on the results of research, the best formula for mixing varnish was 50% of coconut oil, 36% of phenolic resin, and 14% of solvent oil. At the same time, the best formula in producing black offset inks was mixing varnish with 20% of coconut oil 20%. Consequently, the result of testing of properties of coconut oil based solvent offset printing inks regarding viscosity, tack and ink flow, showed that offset printing inks with oil based solvent had the properties less than commercial offset printing ink. Additionally, the result of testing also indicate that the rate of properties in aspects of ink spread and setting time of coconut oil based solvent offset printing were higher than that of commercial offset printing inks.
Abstract: The objectives of this research are to produce
prototype coconut oil based solvent offset printing inks and to
analyze a basic quality of printing work derived from coconut oil
based solvent offset printing inks, by mean of bringing coconut oil
for producing varnish and bringing such varnish to produce black
offset printing inks. Then, analysis of qualities i.e. CIELAB value,
density value, and dot gain value of printing work from coconut oil
based solvent offset printing inks which printed on gloss-coated
woodfree paper weighs 130 grams were done. The research result of
coconut oil based solvent offset printing inks indicated that the
suitable varnish formulation is using 51% of coconut oil, 36% of
phenolic resin, and 14% of solvent oil 14%, while the result of
producing black offset ink displayed that the suitable formula of
printing ink is using varnish mixed with 20% of coconut oil, and the
analyzing printing work of coconut oil based solvent offset printing
inks which printed on paper, the results were as follows: CIELAB
value of black offset printing ink is at L* = 31.90, a* = 0.27, and b* =
1.86, density value is at 1.27 and dot gain value was high at mid tone
area of image area.