scholarly journals THE PHENOMENON OF INK DUSTING TAKING INTO ACCOUNT THE SURFACE ROUGHNESS OFFSET PRINTING PLATE

2021 ◽  
Vol 37 (2) ◽  
pp. 16-24
Author(s):  
I. Khalilov ◽  
E. Aliyev ◽  
E. Huseynzade

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.

2010 ◽  
Vol 1 (1) ◽  
pp. 32-38
Author(s):  
Živko Pavlović ◽  
◽  
Dragoljub Novaković ◽  
Sandra Dedijer ◽  
Magdolna Apro ◽  
...  

2016 ◽  
Vol 4 ◽  
pp. 33-38
Author(s):  
Vasyl Skyba ◽  
Каteryna Zolotukhina ◽  
Olena Velychko

The complex research for the changes in the properties of the printing plates’ printing and gap elements influenced by the printing process short runs was conducted, that allowed to determine the change of printing and gap elements’ surface microgeometry, also to determine the change of the oxide layer stability, and to explain the decrease of the ink receptivity coefficient. The mathematical regression equation model of the printing plates’ elements’ impact onto the imprints’ optical density in offset printing was developed, that allows estimating and predicting properties of modern brand of printing plate. Work reveals some new facts about characteristics for printability such as influences of printing plate’s elements parameters’ on color characteristics of imprints. Dampening solution, printing plates application and printing settings as well as color features of the imprints are analyzed in the context of offset printing.


2014 ◽  
Vol 989-994 ◽  
pp. 3331-3334
Author(s):  
Tao Zhang ◽  
Guo He Li ◽  
L. Han

High speed milling is a newly developed advanced manufacturing technology. Surface integrity is an important object of machined parts. Surface roughness is mostly used to evaluate to the surface integrity. A theoretical surface roughness model for high face milling was established. The influence of cutting parameters on the surface roughness is analyzed. The surface roughness decreases when the cutter radius increases, total number of tooth and rotation angular speed, while it increases with the feeding velocity. The high speed face milling can get a smooth surface and it can replace the grinding with higher efficiency.


2010 ◽  
Vol 102-104 ◽  
pp. 610-614 ◽  
Author(s):  
Jun Chi ◽  
Lian Qing Chen

A methodology based on relax-type wavelet network was proposed for predicting surface roughness. After the influencing factors of roughness model were analyzed and the modified wavelet pack algorithm for signal filtering was discussed, the structure of artificial network for prediction was developed. The real-time forecast on line was achieved by the nonlinear mapping and learning mechanism in Elman algorithm based on the vibration acceleration and cutting parameters. The weights in network were optimized using genetic algorithm before back-propagation algorithm to reduce learning time.The validation of this methodology is carried out for turning aluminum and steel in the experiments and its prediction error is measured less than 3%.


Author(s):  
Vasishta Ganguly ◽  
Tony Schmitz ◽  
Arthur Graziano ◽  
Hitomi Yamaguchi

Magnetic field–assisted finishing (MAF) is used to polish free-form surfaces. The material removal mechanism can be described as a flexible “magnetic brush” that consists of ferromagnetic particles and abrasives that arrange themselves in the working gap between the magnet and the workpiece. Relative motion between the brush and the workpiece causes microcutting and improves surface finish. In this study, the contributions of the magnetic and polishing force components to the total force were evaluated. The effect of varying the polishing conditions, such as the working gap and the size of the ferromagnetic iron particles, on polishing forces, surface roughness, and material removal rate was also analyzed. It was observed that the polishing forces varied considerably with working gap. Also, the iron particle size was found to have a strong relation to the rate at which the surface roughness improved. Surface roughness values of 2–3 nm were achieved.


Author(s):  
Vasishta Ganguly ◽  
Tony Schmitz ◽  
Arthur A. Graziano ◽  
Hitomi Yamaguchi

Magnetic field assisted finishing (MAF) is used to polish free-form surfaces. The material removal mechanism can be described as a flexible “magnetic brush” that consists of ferromagnetic particles and abrasives that arrange themselves in the working gap between the magnet and the work piece. Relative motion between the brush and the work piece causes micro-cutting and improves surface finish. In this study, the contributions of the magnetic and polishing force components to the total force were evaluated. The effect of varying the polishing conditions, such as the working gap and the size of the ferromagnetic iron particles, on polishing forces and surface roughness was also analyzed. It was observed that the polishing forces varied considerably with working gap. Also, the iron particle size was found to have a strong relation to the rate at which the surface roughness decreased. Surface area roughness of 2–3 nm was achieved.


Author(s):  
Fredrik Wallin ◽  
Mark H. Ross ◽  
Max Rusche ◽  
Scott Morris ◽  
Steven Ray

An experimental and numerical investigation of the flow in a compressor duct with engine-realistic in-production features is presented in this paper. The experimental testing was conducted in the ND-FSCC test facility at University of Notre Dame, Indiana, USA. A baseline duct was also tested for back-to-back comparison. The ducts were heavily instrumented; duct inlet and exit flowfields were scanned using a five-hole pressure probe that provided total pressure, velocities and flow angles. Based on the five-hole probe total pressures, duct losses could be assessed. Furthermore the duct inlet boundary layers were traversed and turbulence intensity levels were assessed. For the CFD analysis of the production-like duct, a highly complex computational grid, resolving all the geometrical features present, was used. A previously validated surface roughness model was used to account for the cast aero-surfaces. Both experimental and numerical results show that there is a significant increase in loss for the production-like duct when compared to the baseline duct loss. The CFD results agree very well with experimental results for the baseline duct, which makes it possible to use the experimental data recorded for the production-like duct to validate CFD tools for real geometry effects, such as interface steps and surface roughness for example.


2019 ◽  
Vol 16 (5) ◽  
pp. 572-579 ◽  
Author(s):  
E. A. Maksimov ◽  
E. P. Chelyabinsk

Introduction. Traction power of the car is used to determine its traction-speed properties. The purpose of the paper is the calculation refinement of the car traction power.Materials and methods. The authors used the methodology of the refined calculation of the car traction power.Results. The authors carried out the comparative analysis of the refined and traditional methods for calculating traction power. As a result, the authors obtained the refined equation for calculating the traction power, taking into account the elastic modulus, the width of the contact track, the free radius of the wheel, the deflection of the tire and the tangential friction forces in the contact zone. The largest discrepancy between the curve of the vehicle’s traction power calculated by the updated methodology and the curve of the vehicle’s traction power calculated by the traditional method was 26.8%.Discussion and conclusions. The results of the research are useful to specialists of automobile and transport enterprises and masters of universities to compare the traction and speed properties of the various car types.


2011 ◽  
Vol 121-126 ◽  
pp. 2059-2063 ◽  
Author(s):  
Somkiat Tangjitsitcharoen ◽  
Angsumalin Senjuntichai

In order to realize the intelligent machines, the practical model is proposed to predict the in-process surface roughness during the ball-end milling process by utilizing the cutting force ratio. The ratio of cutting force is proposed to be generalized and non-scaled to estimate the surface roughness regardless of the cutting conditions. The proposed in-process surface roughness model is developed based on the experimentally obtained data by employing the exponential function with five factors of the spindle speed, the feed rate, the tool diameter, the depth of cut, and the cutting force ratio. The prediction accuracy and the prediction interval of the in-process surface roughness model at 95% confident level are calculated and proposed to predict the distribution of individually predicted points in which the in-process predicted surface roughness will fall. All those parameters have their own characteristics to the arithmetic surface roughness and the surface roughness. It is proved by the cutting tests that the proposed and developed in-process surface roughness model can be used to predict the in-process surface roughness by utilizing the cutting force ratio with the highly acceptable prediction accuracy.


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