Lithographic 2 3 Colour Sheet Fed Printing Presses P3555126 M
High Speed Inline Coating for Sheet Fed Printing Presses.
-
Upload
kimberly-long -
Category
Documents
-
view
219 -
download
0
Transcript of High Speed Inline Coating for Sheet Fed Printing Presses.
![Page 1: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/1.jpg)
High Speed Inline Coatingfor Sheet Fed Printing Presses
![Page 2: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/2.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Preconditions
- up to 12,000 prints/h the usual processing instructions are to be observed
- for High Speed Inline Coating with a printing speed of up to 18,000 sheets/h the processing range must be adapted regarding
- substrate- ink layer thickness- coating viscosity- coating selection- performance of the dryer- distance under the dryer
![Page 3: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/3.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Substrate - Ink
- the combination of substrate and ink should be selected in a way to assure a good bond between ink and substrate
- poor ink drying cannot be improved by coating
- the result is bad rub resistance and insufficient scotch tape resistance
![Page 4: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/4.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Adhesion Substrate - Ink
Paper
Ink C oating
![Page 5: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/5.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Ink Layer Thickness
- Overinking of the ink layer thickness with parallel inline coating will reduce the performance of the printing press
- as by reducing the printing speed the drying time is adjusted
![Page 6: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/6.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Paper Paper
Ink C oating Ink C oating
Normal Inking Overinking
Ink Layer Thickness
![Page 7: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/7.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Cell Volume of the Screen Rollers
- the cell volume of a screen roller is indicated with the scoop amount of water in ml/m²
- the coating application amount corresponds to about 1/3 of the indicated cell volume of the screen roller
Example:
A cell volume of the screen roller
of 15 g/m² corresponds to approx 5 g/m² coating application
![Page 8: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/8.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Gloss Diagram after 24h Drying
30
35
40
45
50
55
0 5 10 15 20
Glo
ss i
n %
Drying Time in h
3 g/m²2 g/m²
1 g/m²
Wet-on- Wet Printing
![Page 9: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/9.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Coating Viscosity
- the coating viscosity depends on the temperature and is determined with a 4 mm DIN cup at 20°C
- when the temperature in the coating rises the viscosity will decrease
- in case of a viscosity decrease, e.g. below 25 sec., an even coating application cannot be assured any more
![Page 10: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/10.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Viscosity depending on the Temperature
Vis
cosi
ty i
n s
20
40
60
80
100
15 25 35 45
Temperature in °C
![Page 11: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/11.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Variable Coating Viscosities
Cooling Units for Coatings by EASYLAC keep the coating stable in viscosity
![Page 12: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/12.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Too high Coating Viscosity
- a too high coating viscosity, e.g. above 65 sec. can be adjusted by dilution with water to the required viscosity
- a too high coating viscosity in connection with High Speed Inline Coating will lead to splashing
![Page 13: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/13.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Dilution of the Coatings with Water
20
30
40
50
60
70
80
0 4 8 12 16 20
Vis
cosi
ty in
sec
.D
IN 4
mm
Cu
p a
t 20
°C
approximate Water Amount in %
![Page 14: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/14.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Coating Selection
- the drying behaviour of coatings depend on the coating type
- if for example the following coating types are used:
- matt- semi matt- protection- gloss- high gloss- UV coatings
their drying behaviour will be considerably different
![Page 15: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/15.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Coating Selection
For dispersion coatings:
The higher the gloss, the slower the thorough drying
Rule of thumb:
![Page 16: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/16.jpg)
0
10
20
30
40
50
60
70
80
90
CartonGD2-
printed
DL 1176 DL 1351 DL VP385
DL 1200 DL 1300DL 1650
DL 1150 DL VP9756
Gloss in % Drying time in s
High Speed Inline Coating for Sheet Fed Printing Presses
Gloss Diagram: different coatings on the same substrate
![Page 17: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/17.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Influence of the Surface Structure of the Substrate
30
40
50
60
70
80
0 2 4 6 8 10 12
Carton 1
Carton 2
Application Amount g/m² wet
Glo
ss i
n %
![Page 18: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/18.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
UV Coatings
- UV coatings dry immediately by photo-polymerisation using short wave light
- the acetone test shows whether the coatings have dried thoroughly
![Page 19: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/19.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Performance of the Dryers
- the drying behaviour of the coatings is determined by the performance of the dryer
- the thorough drying of dispersion coatings is primarily determined by the available amount of air
The more air, the better for the thorough drying- beginning at a pile temperature of approx. 35 °C problems may occur in the pile
![Page 20: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/20.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Drying of UV Coatings
- for UV coating processes the condition of the UV lamps and a sufficient performance are responsible for a good coating result
- the temperature in the pile is also decisive for UV coatings and may be responsible for subsequent problems in print finishing
- too high temperatures may result in breaking of the printed matter during the grooving and folding process
![Page 21: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/21.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Drying Distance
An extended delivery between coating tower and delivery is advantageous for the printing speed.
A short delivery is a disadvantage for High Speed Inline Coating.
![Page 22: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/22.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Printing Press with Double Extended Delivery
![Page 23: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/23.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Special Coating Applications
- for special coating applications, as e.g. application of blister coating, a coating amount of 6 – 8 g/m² has to be applied in order to assure good bonding with the plastic foil
![Page 24: High Speed Inline Coating for Sheet Fed Printing Presses.](https://reader033.fdocuments.us/reader033/viewer/2022061305/5513f5c65503466f748b5e59/html5/thumbnails/24.jpg)
High Speed Inline Coating for Sheet Fed Printing Presses
Result
High Speed Inline Coating with 18.000 prints/h will not present any problems if the appropriate coatings are used and the printing press is well adjusted.