1. Industrial Automation Automation Industrielle Industrielle Automation
Automation of newspaper printing machines: visit at CIEL
Prof. Dr. H. Kirrmann
ABB Research Center, Baden, Switzerland
2006 April, HK, 1/36

2. Offset printing
The most common form of printing low and high-volume jobs used today is "offset" - used for everything from fliers to magazines and newspapers.
Offset printing uses an intermediate medium between the printing plate and the paper - the rubber-coated "blanket" is inked by the plate roller under relatively low pressure, to prevent the image from deforming. Half a revolution later the same image is printed on sheet or continuous (web) paper under much higher pressures. The plate is continually inked to maintain the image on the blanket.
Printing plates don't have any "relief" - there is no change in depth where the image isn't printed - instead the plate uses Teflon to repel water from some areas.

3. Offset plates
The printing plate is initially coated with a light-sensitive material that protects the water-repellent Teflon layer below - this top layer retains water, preventing ink from building up and being printed on the blanket.
In areas where the Teflon has been revealed water will not stay on the surface of the plate, but ink will - hence the exposed areas are those that 'print'. The coating of the plate is removed using a photographic process and (typically) a negative copy of the image-setter films.
To produce the plate, films are held in place over the coating (usually via a vacuum frame to ensure perfect contact) while areas of the plate are exposed by a high-intensity UV light source. The plate is then chemically processed to expose the Teflon and fix the coating.

4. Halftones - Dot Shape, Screen Ruling and Screen Angles
To give the illusion of a continuous tone image when printed, all images have to be recreated using "halftone" patterns of regularly spaced ink dots, of varying sizes.
The size of these dots, measured in a percentage tint, represents the lightness/darkness of each small area of the image.
The spacing of the dots is the "screen ruling", normally measured in Lines per Inch (lpi).
To "fool" the eye into seeing a continuous tone image, the lines of dots are very close together: typical line screen rulings are 133 lpi for mono (sometimes 120 lpi) or 150 lpi for colour (or higher). Although these general values are valid for "conventional" printing, uncoated stocks and especially newsprint dramatically reduce the line screens used (e.g. 100 lpi mono / 120 lpi colour).

5. web lead plate cylinder printing cylinder Colour printing
bande de papier
Papierband
web lead
Colours are reproduced by combining four inks: (CMYK) Cyan, Magenta, Yellow, blacK
A page printed in full colour must therefore pass through four cylinders, in the order CMYK.
plate cylinder
printing cylinder

6. Moiré and rastering
Overlaying several halftones produces interference patterns, called "moiré".
The most effective dot shape in 4-colour printing is elliptical - this allows overlaid colours to be "angled" to minimise interference.
The angle between Cyan and Magenta is critical as interference is obvious;
Yellow is far less critical as the colour is so light against white paper;
Black will give interference effects but is usually only reinforcing dark areas of an image where moiré is obscured.
The screen ruling (measured in lines per inch) varies between colours to reduce “rosette” patterns - the four "irrational screening" angles will usually average the output LPI, with black typically the highest ruling, angled at 45º.

7. Computer-to-Plate
In Computer-To-Plate (CTP), there are no films anymore: the plates are directly etched by a powerful laser and treated chemically.
The plate precision is in the order of 0.05 mm, so that the different colours blend without visible shadows.
The next step will be Computer-to-Cylinder: there will be no more plates, the cylinders will be directly written by a laser (and erased for the next production). However, this technology is not yet mature and the number of copies produced in one run (before rewriting the cylinder) is insufficient for a newspaper production.

8. ink water Around a cylinder plate rubber cylinder (blanket)
homogenizer
water
faucets
ink supply

9. Two cylinders
plate
rubber blanket
rubber
blanket
plate

10. Cylinder arrangements
each manufacturer has its preferred cylinder arrangement

11. Tower and Folder tension value draw roller web 25 dN/m turner bar
bande
tension value
draw roller
web
25 dN/m
turner bar
barres de retournement
upper H
entonnoir
tour d'impression
folder
cylindres
lower H
20 dN/m
folder roller
infed
débiteur
12 dN/m
plieuse
dancer roller
trotteuse
reelstand
bobines

12. The folder
The folder folds one or several webs into bundles ("cahiers").
(picture taken while introducing the paper in the machine)

13. Simple and Double production
simple production
one newspaper per rotation of the cylinder – all plates of a cylinder are different
double production
two newspapers per rotation of the cylinder – the same plates are mounted twice on the cylinder. 16 12 1 5 14 3 8 6 1 3 8 6 1 3
cylinder
(flattened) 10 7 16 12 1 5 14 3 10 7 5 6 5 6 8 1 8 1 16 1 14 3 12 5 10 7 1 1 1 1 1 1

14. Web path web colours turner bar bars web folder web width
couleurs des bandes
turner bar
barres de retournement
bars
web
folder
plieuse
web width
largeur de la bande
reelstands, changeurs de bobines

15. Paper colour and cylinder arrangement
Every newspaper is different. The web path is switched after each production and the paper is thread in by a carrier system.

16. Web tracks (Chemins de papier)
Nearly every production requires a different threading

17. The transporter
The transporter carries the printed newspapers
to the expedition.
En route, insets (advertising, prefabricated parts) can be
inserted.

18. Drives
The cylinders were formerly connected by a shaft (Axe, Welle).
Today, the shaft is replaced by an electronic synchronization based on a hard real-time bus, SERCOS.
The precision of the drives position is about 0.05 mm, i.e. 2.5 microseconds at 20 m/s web speed.

19. Section control
A section is a number of towers producing into exactly one folder
(towers can be assigned to different folders depending on the number of pages).

20. Several sections (folders)

21. Example WIFAG machine THE DALLAS MORNING NEWSU
Sectionbus AF100/2 RC T RS CC PM
Backup EP
Key of Symbols
Lower H-Unit Control (AC110)
Mounted in Bridge
Upper H-Unit Control (AC110)
Turner Bar Unit Control (AC110)
Mounted on Press S
Section Unit Control (AC110)
Mounted in Cubicle SK F
Folder (Double) Unit Control (AC110) G
General Fct Unit Control (AC110)
Mounted in Cubicle NK
Reelstand Coupler (CS31)
Linebus AF100 RC
THE DALLAS MORNING NEWS
ArcNet
Sectionbus AF100/1 T3 T6 F T S F1 T8
T10 T4 L U
R11 T1 T2 T5 T7 S T9 R2 RS R1 R8 R6 R4 R3 R5 R7 R9
R10 L
RIP Interface to Parascan
Report
Printer
MPS Inform 710
(Option) PC U 1 U 2
Terminal Server
Bridge
Remote
Diagnosis
Modem
Ethernet
Report
Printer
DB Server and
Workplace
MPS Production Computer 760
DEC
Personal Workstation
Backup DB Server and
Mounted in Cubicle SK RS
Reelstand Control System (WPOS)
Mounted on Reelstand PM
PressMaster System
Mounted in Cubicle PMR CC
MPS Control Console (LS)
Ethernet CC PM EP
Event & Fault Printer PD
MPS Prod. Computer Distribution
Integrated in Cubicle MRV PD

22. The console
The console allows to:
load the machine configuration
save the settings
adjust the ink and water for each page
display the state of the machine
display alarms and events
support diagnostics
Console = Leitstand, pupitre

23. Console: adjusting the colour for each lane (screw)
a page is divided into lanes, each each controlled by a "screw“ that adjusts the ink and water
("vis d'encrage“ Farbschraube)
in the console at right, 11 lanes are visible

24. Console: adjusting the web tension
the web tension defines the print quality, it varies as the machine warms up and humidity changes, but shall not lead to paper tear.

25. Console: Alarms
there are some 1000 different alarms, categorized by severity.
Alarms must be acknowledged.

26. displayed with Acrobat
Console: On-line help
By clicking on ?
a help text
corresponding to the
actual windows is
displayed with Acrobat

27. Control Structure of an H
Work controller
IBS long-distance bus
SERCOS
-drive
IBS-M
Display
Local bus BA
DIO
MCU
LBA
check controller
loop IO IO IO IO
IBS-M BA
AIO
MCU
LBA
loop IO IO IO IO
IBS safety bus
functions:
local display, local command buttons, supervision of paper tear, color screws, water
Turmbus

28. Networking a printing machine section
to production preparation
(Ethernet)
bridge
standby
standby LS LS LS PM PM GW GW
Pressmasterbus (Ethernet)
Section bus C (AF100)
V-Sercos
V-Sercos
V-Sercos
Towers
IBG
IBG
IBG
V-Sercos
Interbus-S 4G
IBG
IBG
IBG
IBG
Interbus
Interbus
Interbus
H-Sercos
KT94
KT94
KT94
KT94
KT94
KT94
H -PLCs
KT94
KT94
KT94
KT94
KT94
KT94
KT94
KT94
Service-ARCnet
Falz- und
Tower-ARCnet
AC160
AC160
AC160
Wendeturm-
AC160
Turmsteuerung
Turmsteuerung
Turmsteuerung
steuerung
Section bus B
Section bus D
Section bus C
Line bus - AF100
Rollen-
Rollenwechsler-
wechslerkoppler I
KT94
MR93
Sektions-
Sektions-
koppler A
steuerung
AC160
steuerung
Oxydry-Arcnet
Interbus-S
Reelstands
KT94
ODC
Auro
Oxydry
PECOM-ARCnet

29. Multiple sections MPS MPS Production MPS Control Console LS LS LS PM
tower and folder
control B E C D
SS2
SS3
SS4
SS5
Section Control
OP1
Oxydry (washing)
reelstand control
Reelstands

30. Speed and hierarchy response time MPS production Messages Ethernet
consoles
Arcnet
section control
section control
AF100
tower/folder control
tower/folder control
tower/folder control
Interbus-S
cylindres
SERCOS
motors
Process variables

31. Organisation of newspaper production

32. Production Order

33. Roll logistics

34. Prepress and Workflow with MPS Cockpit

35. WIFAG
Based in Bern, worldwide number 3
WIFAG and ABB pioneered the shaftless press, which is standard today.