Exploring on the Print-through Criterion of Offset Printing

2013 ◽  
Vol 785-786 ◽  
pp. 1582-1585
Author(s):  
Yong Gang Yang ◽  
Li Li Mu ◽  
Yang Lu
Keyword(s):  
Printing Press ◽  
Offset Printing ◽  
Paper Properties ◽  
Printing Speed

In order to control digitally the print-through, the print-through criterion of offset printing was studied in this article. For 4 given paper samples, the paper properties including paper opacity and K&N ink absorbency were tested, and then print-through value expressed with ΔDand ΔEab*was measured under 9 sets of printing condition. The results showed that lower printing press and higher printing speed were helpful to reduce the print-through. And under the same printing conditions, the print-through value of cyan ink print was slightly larger than that of magenta ink print. In addition, the print-through values of offset paper samples were a bit larger than that of newsprint samples. In particular, no matter what kind of conditions were, the print-through value expressed with ΔDand ΔEab*were lower than 0.04 and 4NBS when thePTRvalue was larger than 72%. The criterion of print-through was firstly given, which was very helpful to choose paper during the offset printing.

Preliminary Study on the Print-through Standard of Offset Printing

2011 ◽  
Vol 332-334 ◽  
pp. 1812-1815
Author(s):  
Yong Gang Yang ◽  
Fu Ping Liu
Keyword(s):  
Printing Press ◽  
Offset Printing ◽  
Paper Properties ◽  
Preliminary Study ◽  
Printing Speed

In order to control digitally the print-through, the print-through standard of offset printing was studied in this article. For 4 given paper samples, the paper properties including paper opacity and K&N ink absorbency were tested, and then print-through value expressed with ΔD and ΔEab* was measured under 9 sets of printing condition. The results showed that lower printing press and higher printing speed were helpful to reduce the print-through. And under the same printing conditions, the print-through value of cyan ink print was slightly larger than that of magenta ink print. In addition, the print-through values of offset paper samples were a bit larger than that of newsprint samples. In particular, no matter what kind of conditions were, the print-through value expressed with ΔD and ΔEab* were lower than 0.04 and 4NBS when the PTR value was larger than 72%. The standard of print-through was firstly given, which was very helpful to choose paper during the offset printing.

Use of confocal laser scanning microscopy and a computer model to understand ink cavitation and filamentation

TAPPI Journal ◽  
2010 ◽  
Vol 9 (10) ◽  
pp. 7-15
Author(s):  
HANNA KOIVULA ◽  
DOUGLAS BOUSFIELD ◽  
MARTTI TOIVAKKA
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Print Quality ◽  
Length Scale ◽  
Offset Printing ◽  
Significant Difference ◽  
Printing Speed

In the offset printing process, ink film splitting has an important impact on formation of ink filaments. The filament size and its distribution influence the leveling of ink and hence affect ink setting and the print quality. However, ink filaments are difficult to image due to their short lifetime and fine length scale. Due to this difficulty, limited work has been reported on the parameters that influence filament size and methods to characterize it. We imaged ink filament remains and quantified some of their characteristics by changing printing speed, ink amount, and fountain solution type. Printed samples were prepared using a laboratory printability tester with varying ink levels and operating settings. Rhodamine B dye was incorporated into fountain solutions to aid in the detection of the filaments. The prints were then imaged with a confocal laser scanning microscope (CLSM) and images were further analyzed for their surface topography. Modeling of the pressure pulses in the printing nip was included to better understand the mechanism of filament formation and the origin of filament length scale. Printing speed and ink amount changed the size distribution of the observed filament remains. There was no significant difference between fountain solutions with or without isopropyl alcohol on the observed patterns of the filament remains.

Aeroelastic instability of paper sheet in an offset printing press

2021 ◽  
Author(s):  
Petr Šidlof ◽  
Jan Kolář ◽  
Pavel Peukert ◽  
Martin Pustka ◽  
Pavel Šidlof
Keyword(s):  
Printing Press ◽  
Paper Sheet ◽  
Offset Printing ◽  
Aeroelastic Instability

Development of Modularized Inline Coating System of Multi-Color Offset Printing Press

2013 ◽  
Vol 312 ◽  
pp. 525-528
Author(s):  
Ji Bin Zhao ◽  
Cheng Nan Tong ◽  
Zhao Hua Wang ◽  
Fan Wu
Keyword(s):  
Printing Press ◽  
Coating System ◽  
Offset Printing ◽  
The Press ◽  
New Type ◽  
Printing Machine

A new type of inline coating system is designed and developed. The coating system can be mounted into printing press instead of blanket cleaner. An anilox roller and a sealed duct on the glazing oil transferring part for supplying and transferring the coating oil are introduced. A set of pressure adjusting mechanism is designed for changing the pressure between anilox roller and blanket cylinder, while a set of on-off impression mechanism is arranged to change the position of anilox roller and the on-off impression state. The press can print as normal when the coating system is dismounted. With this coating system, the press can coat prints with glazing oil. This system can be mounted in various type of printing machine. One new type of glazing technology named reverse coating can be achieved when it is mounted in multicolor press.

Printability Analysis of Compostable Films by Flexographic Water Based Ink

2020 ◽  
Vol 843 ◽  
pp. 26-32
Author(s):  
Aran Hansuebsai ◽  
Samatcha Nawakitwong
Keyword(s):  
Surface Roughness ◽  
Quality Parameters ◽  
Image Resolution ◽  
Printing Press ◽  
Print Quality ◽  
Tone Reproduction ◽  
Water Based ◽  
Flexographic Printing ◽  
Set Up ◽  
Printing Speed

This research analyzed the printability of compostable films commercialized in the Thai market such as PLA/PBAT and PBAT/starch; and to comply with EN 13432 standard by using flexographic water based ink. A narrow web flexographic printing press was set up and opperated. Print quality parameters such as optical density, tone reproduction, print contrast and print uniformity were investigated. Results showed that these compostable films were hydrophobic in nature, in combination with fracture and voids of substrates’ surface. Even the substrates could be printed relatively well but showed poor ink adhesion. Surface treatment, therefore, was necessary, but having limitation. Anilox line screen 700 lpi and printing speed at 30 m/min were preferable to achieve the optimum tone reproduction and print contrast. This was based on the image resolution of 133 lpi and corona dosage at 500 watt-min/m2. Images of printed samples from SEM and SPM indicated that the fracture surface and void of films could lead to decrease their printability. It was found that starch blend gave better results as being a filler of the surface roughness of the substrate..

A Brief Analysis of Vibration on the Printing Area in Ordinary Offset Press

2012 ◽  
Vol 591-593 ◽  
pp. 2091-2094
Author(s):  
Ming Yang ◽  
Jin Yao Li ◽  
Jia Cong Chen ◽  
Shi Jia Kong
Keyword(s):  
Product Development ◽  
Noise Reduction ◽  
Mechanical Vibration ◽  
Practical Experience ◽  
Printing Press ◽  
Print Quality ◽  
Offset Printing ◽  
The Press ◽  
Vibration Performance ◽  
Printing Presses

At the development of modern printing, vibration may course some products quality problems when increases the speed. Practical experience shows that the mechanical vibration of the offset press is an important reason to affect the print quality. Therefore, improving the vibration performance of the printing press and designing the structure of anti-vibration and noise reduction to improve the quality and speed of printing presses is an important issue in the press product development. This paper proposes some reasons and solution ideas of vibration on printing parts in ordinary offset printing machines.

scholarly journals Paper surface efficiency and inkjet colour reproduction on invasive and agro residue papers

2020 ◽  
Author(s):  
Igor Karlovits ◽  
◽  
Gregor Lavrič ◽  
Keyword(s):  
Inkjet Printing ◽  
Surface Characteristics ◽  
White Paper ◽  
Ultrasound Measurement ◽  
Offset Printing ◽  
Paper Properties ◽  
Paper Surface ◽  
Negative Linear Correlation ◽  
Modified Surface ◽  
Uniform Manner

Paper surface efficiency was developed by Preucil and was intended to define the colourimetry and geometrical part of the light reflection with paper surface values. The surface characteristics of paper, primarily its roughness and absorptivity affect colour reproduction beside the ink pigments or dye. Rougher paper surfaces scatter the light in a more non-uniform manner while paper absorption may cause ink vehicle absorption and thus decreasing gloss, or it may absorb both vehicles and pigment-producing an unexpected colour shift. The formula was upgraded with paper whiteness values as the basic formula did not explain the whole phenomena. These paper properties were the foundation of the paper standardisation for standardised printing. On the other hand, during inkjet printing, a limited amount of liquid is deposited onto a paper surface. When the droplet hits the surface, it starts to spread and wet the surface depending on the ink and paper properties and had different colourant deposition from the formulas used mainly for offset printing inks. In this paper, we have researched the modified surface efficiency formula applied to inkjet printing (HP PageWide Pro 477dw) on invasive and agro-residue papers with specific non-white paper shades. We have measured the dynamic liquid penetration using ultrasound measurement to model the surface behaviour of the inks and measured CIE LCH values of the samples and calculated the CIE ΔE00 colour differences and the influence of paper surface efficiency and paper shade influence on the colour reproduction. The results indicate that using recalculated Cobb Absorption values gives good negative linear correlation with the original formula regarding the magnitude of colour difference.

Evaluation of cut quality of woodfree coated papers

TAPPI Journal ◽  
2013 ◽  
Vol 12 (9) ◽  
pp. 9-15
Author(s):  
BENOÎT DUFOUR, ◽  
WOLFGANG BAUER ◽  
JEAN-FRANCIS BLOCH
Keyword(s):  
Coating Layer ◽  
The State ◽  
Point Of View ◽  
Test Method ◽  
Offset Printing ◽  
Paper Properties ◽  
Coated Papers ◽  
Cut Quality ◽  
Printing Papers

Dusting and blanket pollution are of particular interest in offset printing. Papers must be free of dust and loose particles to drastically reduce the wash interval of the blankets. Those particles are mainly generated during converting operations, such as sheeting. Considering the end-customer point of view, the visual aspect of the cut appears to be very important. To study in detail the influence of the sheeting parameters and paper properties on cut quality, a new test method to quantify the cut quality of woodfree coated papers has been developed. In particular, this method takes into consideration the state of the coating layer near the cutting edges.

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