Changes in the surface roughness of aluminium oxide (non-printing) areas on offset printing plate depending on number of imprints

The paper investigates the influence of the mechanics of a friction printing pair on ink dusting in the printing process, taking into account the surface roughness of the printing plate. The aim of the study is to determine the influence of the surface roughness of the printing plate on the deformation of the deckle, as well as on the value of the total force in the area of the printed contact, the relative gear ratio and the relative speed of sliding of the deckle along the surface of the cylinder, which directly affects the dusting of the ink. It was found that when studying the mechanics of a printed pair, the influence of the microgeometry of the contacting surfaces on the parameters under study was not taken into account. The influence of microprotrusions of the surface roughness of the printing plate on the deformation of the deckle in the area of the printed contact has been substantiated and established. To determine the introduction of surface roughness irregularities, a discrete roughness model is used, presented as a set of identical spherical segments. To determine the influence of the surface roughness of the printing plate on the friction force arising in the contact zone, a calculation scheme is proposed that differs from analogs. A method is developed for calculating the parameters of a friction pair in the printing process, taking into account the roughness. Expressions are obtained for determining the total moment of tangential friction forces in the sliding sections when spherical irregularities are introduced. According to the proposed technique, the corresponding graphical dependences of the gear ratio on different parameters of the friction printed pair are shown. The advantages of this study in comparison with analogs are that at certain values of the parameters of the friction pair, taking into account the surface roughness of the printing plate, also at known values of the mechanical characteristics and thickness of the deckle, it is possible to determine the change in the length of the deckle of a given composition, which is necessary in the printing process. The proposed calculation method, which is carried out without taking into account the pressure in the printed contact zone, allows predicting the quality of printed impressions and the amount of ink involved in the formation of ink dusting, as well as correctly adjusting the printing press before the printing process.

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Particle detachment due to wheel rotation

Indoor and Built Environment ◽

10.1177/1420326x20935162 ◽

2020 ◽

pp. 1420326X2093516

Author(s):

Jinwei Song ◽

Hua Qian ◽

Xiaohong Zheng

Keyword(s):

Surface Roughness ◽

Silicon Dioxide ◽

Adhesion Force ◽

Aluminium Oxide ◽

Theoretical Models ◽

Wheel Speed ◽

Spherical Particles ◽

Wheel Surface ◽

Particle Detachment ◽

Oxide Particles

Particle detachment induced by a rotating wheel was investigated theoretically and experimentally. The developed theoretical models were used to reveal how the particle detaches from a wheel surface to the surrounding air. The corresponding experiments were carried out to validate proposed models. Two groups of spherical particles were considered, i.e. silicon dioxide and aluminium oxide particles. Different forces and force moments acting on individual particles were analysed. The criteria for the rolling detachment of particles were considered. The detachment diameters under various conditions were calculated. The results show that the particle detachment was dominated by the removal and resistant forces acting on particles, including the gravity force, adhesion force, hydrodynamic force and centrifugal force. Different relevant parameters can affect particle detachment through these forces, including surface roughness, wheel speed, particle size and properties. A higher wheel speed, larger particle sizes and higher wheel surface roughness were shown to have a conducive influence on particle detachment. The resistant and removal force moments could be affected by the particle properties at the same time; therefore, the detachment diameters of the aluminium oxide particles are similar to those of silicon dioxide. This study can contribute towards the estimation of particle emissions from vehicles.

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Discussion on Application of 3D Printing Technology in Package Printing

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.731.300 ◽

2015 ◽

Vol 731 ◽

pp. 300-303 ◽

Cited By ~ 1

Author(s):

Chen Fei Zhao ◽

Dan Hui Wu

Keyword(s):

3D Printing ◽

Printing Industry ◽

Offset Printing ◽

Printing Plate ◽

Printing Technology ◽

3D Printing Technology ◽

Advantages And Disadvantages ◽

Ink Jet ◽

Jet Printing ◽

Printing Machine

The principle of 3D printing technology is based on the basic principle of ink-jet printing. The application of 3D printing in packaging printing is discussed, including printing history, development present situation, the principle, equipment, the advantages and disadvantages of 3D printing. The application of 3D printing in digital printing machine manufacturing and in offset printing plate making and screen plate making is studied. This paper is of great significance for the transformation of the printing industry.

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Evaluation of wetting state on a surface of offset printing plate using speckle measurement

Journal of the Visualization Society of Japan ◽

10.3154/jvs.26.supplement2_103 ◽

2006 ◽

Vol 26 (Supplement2) ◽

pp. 103-106

Author(s):

Makoto KONISHI ◽

Shigeru MURATA ◽

Masatsugu MIZUTA

Keyword(s):

Offset Printing ◽

Printing Plate

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A New Offset Printing Plate Using TiO2 Photocatalyst

Journal of Japan Association on Odor Environment ◽

10.2171/jao.40.101 ◽

2009 ◽

Vol 40 (2) ◽

pp. 101-108

Author(s):

Taketoshi MURAKAMI ◽

Kazuya NAKATA

Keyword(s):

Offset Printing ◽

Printing Plate

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THE INFLUENCE OF FEED RATE ON SURFACE ROUGHNESS OF TIC–WC CARBIDE AND AL2O3 CERAMICS SAWN-OFF WITH INNER EDGE OF DIAMOND DISC

Mokslas - Lietuvos ateitis ◽

10.3846/mla.2010.078 ◽

2010 ◽

Vol 2 (4) ◽

pp. 88-90

Author(s):

Raimundas Mikolaitis ◽

Valdas Bukauskas ◽

Vadim Mokšin ◽

Vytautas Striška

Keyword(s):

Surface Roughness ◽

Grain Size ◽

Tungsten Carbide ◽

Feed Rate ◽

Aluminium Oxide ◽

Cutting Process ◽

Feed Speed ◽

Average Roughness ◽

Cutting Machine ◽

Diamond Disc

The paper presents results of measurements of surface roughness of titanium-tungsten carbide (T14K8) and aluminium oxide (Al2O3) ceramics surfaces sawn-off with inner edge of diamond disc. The cutting process was performed by cutting machine “АЛМАЗ-4” with 60/40 grain size disc. The dependence of average roughness Ra of the sawn-off surface on feed speed of the workpiece was established.

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Statistical analysis of the influence of print run on surface roughness of digital flexo printing plates’ solid tone areas

Proceedings - The Tenth International Symposium GRID 2020 ◽

10.24867/grid-2020-p30 ◽

2020 ◽

Author(s):

Sandra Dedijer ◽

◽

Magdolna Pál ◽

Ivana Tomić ◽

Stefan Poljak ◽

...

Keyword(s):

Surface Roughness ◽

Statistical Analysis ◽

Statistical Evaluation ◽

Statistical Significance ◽

Test Method ◽

Roughness Parameters ◽

Printing Plate ◽

Significance Level ◽

Surface Roughness Parameters ◽

The Difference

In this study we have aimed to present statistical evaluation of changes in the surface roughness of the solid tone areas on CtP flexo printing plate in dependence of print run. Changes in flexo plate surface roughness is influenced by the plate-making process, printing pressure and speed, the interaction with the ink and printing substrate and by the wear of the printing plate due to long print-runs. Thus, the aim of this research was to evaluate the changes in the amplitude surface roughness parameters (Ra, Rp, Rv and Rz), between the printing plates used for different print runs. In the experiment, we have employed three sets of CtP flexo printing plates, for three colors-cyan, magenta and blue. The first set was not used for printing, the second was used to print 7 rolls of substrate and the third is used to print 11 rolls of printing substrate. The amplitude surface roughness parameters were compared by applying independentsamples t-test method using the software SPSS (Statistical Package for Social Science) with a 0.05 significance level. Statistical analysis revealed that the difference between the amplitude surface roughness parameters measured on CtP flexo printing plates are significant with a 95% confidence level, whereas the statistical significance pointed out that with the longer print runs, the difference will be strongly expressed.

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Investigation of the influence of cementation of chromium onto aluminium on the characteristics of non-printing elements of an offset printing plate

Hemijska industrija ◽

10.2298/hemind0405232z ◽

2004 ◽

Vol 58 (5) ◽

pp. 232-236

Author(s):

Predrag Zivkovic ◽

Nenad Ilic ◽

Jovan Popic ◽

Slobodan Jovanovic ◽

Konstantin Popov

Keyword(s):

Contact Angle ◽

Statistical Analysis ◽

Electrochemical Deposition ◽

Digital Camera ◽

Trivalent Chromium ◽

Alkaline Solutions ◽

Distilled Water ◽

Offset Printing ◽

Printing Plate ◽

Drop Spreading

The possibility of the electro less deposition of chromium onto aluminum was investigated in order to improve non-printing element properties. It was determined that the electrochemical deposition of trivalent chromium was possible from alkaline solutions. The presence of chromium was confirmed by the EDAX procedure in three different laboratories. The influence of chromium on the wet ability of the nonprinting elements of the printing form was examined by drop spreading. Specimens were examined by pouring distilled water in drops onto the surface of the specimen. The picture of the drop was taken by a digital camera from two directions, in order to measure the diameter of the spreaded drop (a measuring gauge was recorded together with the drop) and contact angle. The chromium-treated samples showed increased wettability compared with the non-chromium-treated samples. Improvement of the non-printing elements was confirmed during a printing test that was performed under real printing conditions. The purity of the prints made by two types of printing forms was analyzed in two ways: based on densitometric measurements and based on statistical analysis of the scanned print. Both methods of analysis of the control prints showed that the control prints made from chromium-treated specimens were purer than the prints made from the non-chromium-treated specimens. Considering that all the conditions of making the printing forms and the printing conditions, except the electro less deposition procedure were the same, it could be concluded that the electro less deposited layer of chromium improved the printing properties of the offset printing form because of the increased wettability.

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