Analysis of the color properties of papers subjected to different recycling numbers in electrophotographic (toner) printing

Purpose In this present study, electrophotographic printing is made on papers which are subjected to different recycling numbers, and this paper aims to examine the colour changes of this printing type. Design/methodology/approach Four-colour electrophotographic printing is carried out on adhering to the INGEDE 11p standard recycled papers four times under the same conditions. Colour measurements are made by means of electrophotographic printed colour scales printed on these recycled papers. Colour measurements are made with the X-Rite eXact spectrophotometer according to the ISO 13655:2017 standard. As a result of colour measurements, colour differences (ΔL′, ΔH′, ΔC′, ΔE00) of recycled papers are determined using some formulas. Findings According to the values obtained after four recycling, the highest ΔL′ value is found to be 4.80 yellow and the lowest 1.92 black. Again, according to the measurement results, it is determined that the highest ΔE00 is yellow colour with a value of 5.66, and lowest ΔE00 is black colour with a value of 1.98. In ΔH′, black colour is the highest value of 12.61, the lowest value with −2.05 is obtained in magenta colour. It was observed that the highest ΔC′ value is 2.98 in yellow, and the lowest value is −0.28 in black. Originality/value In the printing industry, sometimes customers want to monitor the colour differences in the printing by taking the L′a′b′ obtained values as a result of printing from the printing houses. If the colour differences exceed the tolerance values, then they can interfere with the printing. As a result of the calculations, colour changes in electrophotographic printing are observed with many parameters. This study can be a pioneer for the studies that can be done on this subject.

Comparison of Ultrasound Type and Working Parameters on the Reduction of Four Higher Alcohols and the Main Phenolic Compounds

In this paper, studies were conducted by a series of single-factor experiments to investigate the effects of ultrasound types and working parameters on the higher alcohols (HA), phenolic compounds, and color properties of red wine, so as to highlight the importance of the comprehensive consideration on its application. The results indicate that ultrasound devices and working parameters do have some definite influences on the HA of wine; moreover, the ultrasound bath (SB-500DTY) is better than the SCIENTZ-950E and the KQ-300VDE. With the SB-500DTY employed to further investigate its effects on phenols and color properties other than on HA, unexpectedly, some variations of color parameters are opposite to the results ever obtained from other ultrasound conditions. In summary, all these results suggest that both the ultrasound type and parameters should be fully considered or neutralized so as to have a comprehensive evaluation about its application, instead of some contradictory results.

How acetaldehyde reacts with low molecular weight phenolics in white and red wines

Acetaldehyde is a key compound in determining wine color evolution and sensory properties. Major wine metabolites reactive to acetaldehyde are phenolic compounds, mainly flavan-3-ols and anthocyanins. Many studies have been conducted with the purpose of investigating acetaldehyde reactivity in model solutions, but very poor are the reports of its fate in real wines. By means of LC-HRESIMS and UV/Vis HPLC, red and white wines exposed to an excess of acetaldehyde were analyzed with a specific focus on low molecular weight phenolics. The chemical behavior of acetaldehyde turned out to be different in white and red wines. In white wines, it mainly mediated the formation of vinyl-flavan-3-ol derivatives, while in red wines it led to the formation of ethylidene-bridged red pigments. These latter positively enhanced the color properties of red wines. Conversely, in white wines, the formation of compounds, such as xanthylium ions, causing the undesired browning effects were not detected.

Examining Parameters of Surface Quality Performance of Paulownia Wood Materials Modified by Thermal Compression Technique

The aim of this study was to evaluate the effect of thermal compression process on some surface properties of paulownia solid wood materials. The widest surface of wood samples was mechanically compressed at high temperatures. The duration was 45 min. Four different process combinations were created, including two temperatures (150 °C and 170 °C) and two pressure levels (20 bar and 22.5 bar). The surface roughness, wettability and color properties of treated and untreated samples were compared. The roughness properties, both parallel and perpendicular to grain direction, were determined according to JIS B 0601:1994 standard. The contact angle changes of water dripped to the surface were measured according to time. For color properties, a spectrophotometer was used according to CIE L*a*b* system. The color changes were classified according to a grading method from literature. The most remarkable results on wettability were observed. The contact angle values significantly increased with this method. Although higher temperature increased the contact angle values, higher pressures did not change the values. When the surface roughness values were generally considered, this technique could decrease the values up to 40 % ratio according to the control group. Only the combination of 150 °C and 20 bar did not significantly change the values. Lastly, the results of color properties showed that all treatment parameters significantly affected total color change values of samples. Grading results were similar and the color change of modified samples graded as the lowest color difference, except with the combination of 150 °C and 20 bar. The combination of 170 °C and 22.5 bar (highest treatment conditions) significantly changed all color characteristics of samples, except b* parameter. The results of this research showed that mechanical thermal compression method could change surface properties of this fast-growing species.