THE DATA FRONT

58 | l&l
Inspection revolution
A networked 100% inspection system installed by Erhardt+Leimer at converter X-label represents a
major breakthrough in the organization of quality management. Andy Thomas reports
German converter X-label has carried out a groundbreaking
installation of multiple, press-mounted print image inspection
systems networked to its rewinders via a central quality
department. The system was developed and installed by
Erhardt+Leimer, based on the Nyscan 100-percent print
inspection system.
Historically, final inspection of printed labels has been carried
out on inspection-rewinders. The need to stop and position at
all defects - even those that are potentially acceptable – wastes
a lot of time and can prompt the operator to set the sensitivity of
the system at a low level to meet productivity requirements.
Greater cost-effectiveness can be achieved if the print image
inspection systems are installed, not on the rewinder, but on
the press. There are still potential problems, however. Although
waste is detected at an early stage, the press operator now
takes on responsibility for quality, making decisions based on
the feedback from the print image inspection system. Not an
ideal scenario.
The solution developed between Erhardt+Leimer and X-label
involved equipping each printing press with a print image
inspection system with an interface to the IT department
for production data acquisition (PDA). The quality control
department – not the printer - decides whether production is
acceptable or waste. Individual ‘fail’ defects are identified and
Figure 1 - Networking of pre-press, printing, quality control and finishing
differentiated from ‘acceptable’ defects via a Reel Report - a
computerized record of all the defects recorded by the press
camera. The edited reel report automatically controls the
operation of the rewinder.
The practical implementation can be seen in Figure 1. A print
image inspection system is installed on all printing presses
on the site. The PDF artwork is accessed directly by prepress
via the existing EskoArtwork workflow system. On completion
of the printed reel a coded label with the job or reel name is
applied (Figure 2). The press operator now scans the code,
automatically allocating the name and reel-specific data for
that job to the reel report. Data transfer to the central server is
started automatically; from now on the Reel Report for any roll
can be opened using a barcode scanner, allowing complete
integration in the organization's ERP system. The result of
the scan is shown in Figure 3. If a scan is not successful, the
information can also be entered or corrected manually.
As soon as the data is saved on the central server, each
subsequent action is initiated by the presence of a physical
reel at the related station. So when the reel arrives in quality
control, it is identified by scanning the bar code, and the reel
report is loaded automatically for editing. On completion of the
editing process, the reel moves on to finishing, where it is again
identified via the barcode and finished based on the information
contained in the reel report.
Press integration
The print image inspection system at X-label was fully
integrated into the company’s Gallus RCS 330 press (Figure 5).
During makeready, a reference image is taken from the moving
web, allowing all important parameters and inspection zones to
be defined before printing starts. During production, the press
operator can obtain print quality information from any point in
the job, from the start to the current point, using the reel report.
For example, in the case of a repetitive defect on the monitor,
the operator can decide to stop the press to correct a defect
on a printing plate. Figure 6 shows an actual reel report for a
job consisting of two labels across the web. The text defects
currently detected are highlighted in the defect display area.
Once the related bar code label has been scanned, the
edited reel report is automatically transferred from the central
server to the computer on the rewinding machine. The
operator simply presses the Start button and the system stops
automatically, depending on the type of defect, at the splicing
table or the waste rewinding position. ‘Waste areas’ - which
occur predominantly during set-up, but can also be generated
Figure 3 - Acquisition of the job-reel information with the aid of the barcode scanner
Figure 2 - Sealing with
label for reel identification
Labels&Labeling