scholarly journals OPTICAL DENSITY OF YELLOW PRINTS AT COATED AND UNCOATED PAPER

2020 ◽  
Vol 7 (2) ◽  
pp. 9-13
Author(s):  
Gema Sukmawati Suryadi ◽  
Susiani Susiani ◽  
Mawan Nugraha ◽  
Balqis Azhar Ulfah Alifah ◽  
Meuthia Suryani

Optical Density is one of the important parameters used to control print quality. Optical density in print materials is form of interaction of ink with paper. This research is oriented to the investigation of optical density value of Yellow printing ink on coated and uncoated paper. The main purpose of this study is to analyze the effect of printing ink thickness on optimal density value. The optical density value of yellow prints obtained using densitometer measurement, printed using IGT method on coated and uncoated paper. Ink thickness variations are applied (0.8 - 9.6 μm). Density values was found to increase as the ink layer thickness increased to a certain point called the optimal density (2.4 μm ink thickness on coated paper and 4.5 μm on uncoated paper). Optical density of yellow printing ink on coated paper is higher uncoated paper, which relates to porosity on paper

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 816
Author(s):  
Zuzanna Żołek-Tryznowska ◽  
Maciej Rombel ◽  
Georgij Petriaszwili ◽  
Sandra Dedijer ◽  
Nemanja Kašiković

The print quality of prints performed with flexographic printing technology is influenced by various parameters such as viscosity of the printing inks, printing substrates, plates, anilox rolls, etc. The aim of this work is to analyze the influence of ink viscosity, printing plate and printing base on selected properties of print quality, such as optical density of full tone area and the increase of tonal value (TVI). Additionally, the printed dots on 5, 15, 30, 50 and 75% of half tone area were investigated using digital microscopy. The least square fitting method in a matrix form was successfully used in order to confirm the influence of printing process parameters on print quality. The results obtained reveal the significant influence of the printing plate and printing substrate characteristics and the lesser influence of printing ink viscosity for 40–100% coverage area. The values of the optical densities of full tone areas are mainly influenced by the properties of the printing plate and the printing base. Furthermore, the optical density decreases when the value of flow time decreases, which is related to the lower thickness of dried ink film. The TVI on light tones (0 to 20%) is mainly influenced by the ink viscosity.


2013 ◽  
Vol 663 ◽  
pp. 286-290
Author(s):  
Ying Li ◽  
Wen Juan Gu ◽  
Bang Gui He

What happens in the paper surface about ink absorption is of great important for appearance of final printing. The aim of this experiment was to investigate the influence of printing pressure and printing speed on ink layer thickness transferred onto coated paper through quantitative analysis by laser scanning confocal microscope (LSCM). Meanwhile, the influence of printing pressure and printing speed on print density and print gloss were obtained. The results implied that higher printing pressure resulted in higher ink layer thickness, print density and print gloss when printing pressure is less than 700N, but higher printing speed resulted in lower ink layer thickness, print density and print gloss when printing pressure is constant. It could be concluded that the coated paper with high printing speed compared with low printing speed resulted in lower ink absorption, lower print density, lower print gloss and worse printability on the condition of same printing pressure.


2014 ◽  
Vol 8 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Agnieszka Jurkiewicz ◽  
Yuriy Pyr'yev

Abstract According to lots of books, the pressure in offset printing affects the optical density and the quality of printouts. One of the quality parameters is a tone value increase. An advantage of our research method is obtaining printing effects for different pressures on one printout, thus meaning for identical printing conditions. We obtained the same printing conditions through using different amounts of underlay sheets fixed to the blanket cylinder, under a blanket. The pressure was increased from optimal settings - in accordance with the machine manufacturer’s recommendation. The test printouts were printed using Adast Dominant 515, on a coated and an uncoated paper. The optical density value was measured on the tone value scale from 10% to 100% stepping regularly by 10%. For this scale the tone value increase was computed. The research shows that for both types of paper the optical density and the tone value increase changes not very much above the optimal pressure recommended by the machine manufacturer. A difference in the optical density and in the tone value increase is bigger for coated paper than for uncoated paper. Changes in these two parameters are negligible in places where used form 0 to 4 underlay sheets and are quite significant in the place where 5 underlay sheets were.


2021 ◽  
Vol 11 (17) ◽  
pp. 7827
Author(s):  
Dean Valdec ◽  
Krunoslav Hajdek ◽  
Igor Majnarić ◽  
Darijo Čerepinko

This study characterizes and compares the parameters of the quality reproduction of fine elements in flexography on coated and uncoated paper as well as on OPP film (oriented polypropylene). A monochrome test form was created and printed using cyan UV ink. The analysis of results confirms the importance of interaction between the printing substrate and ink; it also indicates identical line and text deformations on the print. Quality reproduction on coated paper is higher in relation to OPP film for all the research parameters. The ink penetrates significantly more and with more irregularity into the pores and throats of the uncoated paper, which results in less homogeneous elements, and in such way that it loses its original shape. In coated paper and OPP film, the ink spreads more on the substrate area which gives it a significantly more homogeneous shape. However, due to the surface spread of the ink, the biggest changes in the size of fine elements are noticeable in the OPP film. The scientific contribution of this paper is based on the comparison of print quality parameters of fine elements, which can contribute to the optimization of the production process and quality of the final graphical product.


2021 ◽  
Vol 933 ◽  
Author(s):  
Yu Liang ◽  
Xisheng Luo

Shock-induced light-fluid-layer evolution is firstly investigated experimentally and theoretically. Specifically, three quasi-one-dimensional helium gas layers with different layer thicknesses are generated to study the wave patterns and interface motions. Six quasi-two-dimensional helium gas layers with diverse layer thicknesses and amplitude combinations are created to explore the Richtmyer–Meshkov instability of a light-fluid layer. Due to the multiple reflected shocks reverberating inside a light-fluid layer, the speeds of the two interfaces gradually converge, and the layer thickness saturates eventually. A general one-dimensional theory is adopted to describe the two interfaces’ motions and the layer thickness variations. It is found that, for the first interface, the end time of its phase reversal determines the influence of the reflected shocks on it. However, the reverberated shocks indeed lead to the second interface being more unstable. When the two interfaces are initially in phase, and the initial fluid layer is very thin, the two interfaces’ spike heads collide and stabilise the two interfaces. Linear and nonlinear models are successfully adopted by considering the interface-coupling effect and the reverberated shocks to predict the two interfaces’ perturbation growths in all regimes. The interfacial instability of a light-fluid layer is quantitatively compared with that of a heavy-fluid layer. It is concluded that the kind of waves reverberating inside a fluid layer significantly affects the fluid-layer evolution.


1970 ◽  
Vol 43 (2) ◽  
pp. 197-206
Author(s):  
MK Alam ◽  
MN Islam ◽  
MA Zaman

Neutron radiography (NR) technique has been adopted to study homogeneity and water absorption behavior of building materials, like double layer silver gray tiles obtained from Concord Real Estate & Building Products, Unit II, Salna, Gazipur, Dhaka, Bangladesh. Measurements of optical density differences between the film background and radiographic images of the dry/wet samples were used for investigation of the present work. The optical density was measured by using the digital optical densitometer (Model 07-424, S-23285, Victoreen Inc. USA). Large variation in optical density values of the radiographic image was observed. From this observation it shows that the rate of water absorption of the tiles increases with increase of immersion time. Through the investigation of radiographic image and subsequently analyzing the optical density we observed that distribution of the elements in the tiles are inhomogeneous. Key words: Homogeneity, Water absorption, Silver gray, Neturon radiography.DOI: 10.3329/bjsir.v43i2.963 Bangladesh J. Sci. Ind. Res. 43(2), 197-206, 2008


2017 ◽  
Vol 50 (3) ◽  
pp. 701-711 ◽  
Author(s):  
Qi Zhong ◽  
Lars Melchior ◽  
Jichang Peng ◽  
Qiushi Huang ◽  
Zhanshan Wang ◽  
...  

Iterative phase retrieval has been used to reconstruct the near-field distribution behind tailored X-ray waveguide arrays, by inversion of the measured far-field pattern recorded under fully coherent conditions. It is thereby shown that multi-waveguide interference can be exploited to control the near-field distribution behind the waveguide exit. This can, for example, serve to create a secondary quasi-focal spot outside the waveguide structure. For this proof of concept, an array of seven planar Ni/C waveguides are used, with precisely varied guiding layer thickness and cladding layer thickness, as fabricated by high-precision magnetron sputtering systems. The controlled thickness variations in the range of 0.2 nm results in a desired phase shift of the different waveguide beams. Two kinds of samples, a one-dimensional waveguide array and periodic waveguide multilayers, were fabricated, each consisting of seven C layers as guiding layers and eight Ni layers as cladding layers. These are shown to yield distinctly different near-field patterns.


KREATOR ◽  
2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Soebardianto . ◽  
Septia Ardiani ◽  
Romi Setiawan

The quality control activities, in particular the measurement of density values, are part of the quality control parameters carried out by each company. Companies sometimes forget about the quality parameters of the name, even though the quality can give the printed products a good guarantee in the eyes of consumers. To achieve the quality level, of course, the business does not stand idle, there are several things that need to be done or provided by the business to support the quality, namely man (human), machine (machine), material (material), and method (method). In the development of technology in an increasingly advanced digital world, companies want to continue to compete with a digital world by making inroads, this of course gives the products produced by the company a good or a good level of quality. In this discussion, there is an identification of problematic aspects arising from the deviation of density values as well as ways to obtain standard density values and factors that affect the quality of prints on book cover prints using a Heidelberg machine.Keywords—Quality Control, Density, Standart, Product, Deviation


Author(s):  
Leyla USLU

In the study, Porphyridium cruentum was cultured under laboratory conditions at 20±2°C, 16:8 (light:dark) photoperiod and continuous aeration to different salinity (20‰, 30‰, 40‰) and two different light intensities (37 µmol m-2s-1 photon and 110 µmol m-2s-1 photon) and growth was determined. Dry matter, optical density and chlorophyll a parameter were used to determine growth. The best growth was determined in culture with a salinity of 30‰ at 110 µmol m-2s-1 photon light intensity. In this group, the optical density (OD) was 1.504±0.003 and the dry matter amount was 1.327gl-1. In the case of 37µmol µmol m-2s-1 photon light intensity, the optical density values were found to be similar in groups with 30‰ and 50‰ salinity and were found to be 1.234±0.004 and 1.215±0.002, respectively. The amounts of dry matter were also similar; 1.168gl-1 and 1.159gl-1, respectively. While the lowest growth was in the culture at 37 µmol m-2s-1 photon light intensity and 20‰ salinity. The optical density obtained on the last day of this group was 1.165±0.004 and the dry matter amount was determined as 0.986gl-1. The amount of chlorophyll a was determined in the cultured groups at the best 37 µmol m-2s-1 photon light intensity.


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