Raising the Bar in Flexo
High quality imaging
High consistency imaging
FPPA Sanibel FL
February 2010
Ian Hole
V P Market Development
EskoArtwork
1
HD Flexo
2
Prepress for Flexo still has some limitations
● Digital CTP (EskoArtwork CDI 75% worldwide) has made big improvements
in Consistency, Productivity and Quality
● BUT the tonal range is still limiting
3
Flexo can have a reduced tonal range
● The minimal printable dot in the
highlights causes:
●
Tonal Jump
●
Color shift
●
Loss of detail
Reduced Tonal Range !
4
So this has limited some applications for Flexo
● Some designs are very hard to print – still printed Offset or Gravure
● Manual adjustment of CT images needed – Bump Curves
– To increase size of non-printable dots – this causes loss of contrast
● Intensive pre-press work sometimes needed
– Different screening needed per object OR
– Splitting jobs into different plates for line and CT’s
● All this increases the complexity
● Increases the cost
● And still limits the quality…
5
Introducing HD Flexo – What is it?
● A new product for 2009 from EskoArtwork
● It revolutionizes digital flexo by offering digital imaging that is
both high quality and still easy to use
● It was developed from strong existing know-how
– 4000ppi Optics – existed since before 2000
– HD Screening Technology – new screening software combination
● HD Flexo is available as a field retrofit for most existing CDI’s and
an option on all new machines
– Retaining all Digital Workflow advantages
6
HighRes Optics: 4000ppi - finer screen dots
● 3x more data to describe the same dot shape
● Dots are more round and dot shoulders are perfectly shaped
● Rounder shape means less Dot Gain
● 4000ppi means dots can be smaller  highlights
● Extended tonal range 0 to 100%
7
data transfer
HighRes Optics: 4000ppi - improved linework
● Linework, Barcodes and Type are imaged more finely on plate
– So it prints cleaner, especially for smaller text
4pt text - 2540ppi
8
data transfer
4pt text - 4000ppi
HD Screens – The best of several worlds
● A combination of several EskoArtwork screens using the best from each –
AM regular pattern, Variable dot sizes, Support dots and Curve choices
● AM dots means the are no isolated dots that can be unsupported
● Variable Dot sizes in highlights  better gradation to zero
● Variable dot range means that dots reach zero at different points in the
gradation – no hard edge
● Plates last longer on print run
● Fewer cleaning cycles are needed on press
● So there is more press uptime (cost saving) and a more stable print
process
9
data transfer
“HD Flexo” achieves a full tonal range – 0% to 100%
0,5% in CT prints with only 2% density.
No need anymore to bump up CT
No loss of image contrast
Pre-press is simpler and quicker – no file conversion
10
HD Flexo: A Case Study
11
Who are Rako Etiketten?
● Label converter headquartered in Germany
– - one of largest producers of self adhesive labels in Europe
● 500+ staff, 34 presses, 18 sites
● Use all print processes
– Offset, Flexo, Letterpress, Screen, Digital
12
Motivation for HD Flexo?
● For - Increased print quality
– Sharper text and line art
– Increased rulings 150 – 200 LPI
– Vignettes down to “substrate” zero
● To - Move jobs from Offset to Flexo
– Flexo printing presses are less expensive (capital equipment cost) than
offset (3x)
– Wastage during startup (to get color OK) is lower for flexo than offset
● 100 feet – 15 feet
– Ink transfer for many label substrates is better with flexo
● increased quality and more versatile
13
What stopped moving jobs to Flexo before?
● Quality expectations could not be met before
– Limitations on screen ruling
– Minimum dot in Flexo to big
● Prepress cost (and time) was greater for Flexo
– Jobs required manual file conversion
– High prepress costs are more than costs of printing Offset
14
Typical production job
● Adhesive label - beauty products
● Design mainly line art, but contains a soft
gradation
– Gradation critical for standard Flexo
– Gradation critical to Dove the customer
– Labels and Cartons printed Offset normally
15
Experience with HD Flexo trials
● Customer printed the same
job both Offset and HD Flexo
● Both sets of plates from the
same digital file
● HD Flexo met customer
expectations
– Quality of HD Flexo was
actually better than Offset
– See following slides for some
micrographs and technical
details
Offset
16
Flexo
HD Flexo: better dot formation
Offset
17
Flexo
HD Flexo: better ink transfer than offset
Offset
18
Flexo
Tonal curve of print sample
Tone curve of HD Flexo in highlights is close to linear. 1% printable
minimum dot
19
Tone curve - highlight region
● Close-up of the highlight shows the excellent min dot behavior of HD Flexo
20
Inline UV
21
UV exposure of Screened dots
Inline UV
22
Conventional Point Light UV
Conventional Bank UV
UV exposure of shadows and reversed images
Inline UV
23
Conventional Point Light UV
Conventional Bank UV
Lifetime of Banklight vs Inline UV
mW/cm²
cm²
20
19
Lifetime extension by increasing
exposure time
18
Plate adjustable Digital UV level
17
16
15
Typical lamp
exchange
14
13
0
250
1250
500
2500
750
3750
1000hh
5000
No UVUV
degradation
over time
(year,
month, week or day)
• 30%
light degradation
over
1000h
Expected Lifetime
= 5000h
• Degradation
is manually
compensated
Digital UV plate
resultsquality
in perfectly
controlled plate production
Unstable
production
24
Plate Surface exposure of Banklight vs Inline UV
mm
mm
1200
Simultaneous movement of the UV
source over the plate
1000
800
Each cm² receives exactly the same
light quality and quantity
600
400
∆ =10%
200
Energy Emmission from lamp to lamp
0
mm
0
500
1000
1500
2000
• Intensity
Uniform dot
variations
shapingdue
throughout
to individual
the whole
lamp aging
plate
• Quality
Cool light
of –
light
no heat
emission
distribution
is varying
to plate
from lamp
or sleeve
to lamp
Resulting
Resulting
in in
a predictable
an unstable and
plate
consistent
quality production
plate quality production
25
Inline UV – Forward Step - Consistency & Automation
● Consistency and Repeatability leading to Automation
EskoArtwork UV technology converts the UV Main Exposure from an
uncontrollable analog process to a high precision digital process.
26
Inline UV - Summary
● Predictable plate quality over years
● Reduced plate wastage
● No Press Down time
● Maintenance Free
Markets
● Mid to Wide Web Flexible Pkg
● High Quality Labels
● High quality Corrugated
● Solvent, Thermal, Water wash
● Sleeves
– No back-exposure
● LetterPress metal backed plates
– No back-exposure
27
Inline UV Main Exposure for Sleeves
Inline UV Main Exposure for sleeves saves an UV-Exposer device
28
Banklight vs Inline UV
Lifetime
mW/cm²
mW/cm²
20
20
Lifetime extension by
increasing exposure time
19
19
18
18
17
17
16
16
15
15
Typical lamp
exchange
14
Plate adjustable Digital UV level
14
13
13
0
250
500
• 30% UV light degradation
750
over 1000h
(each individual lamp)
• At least 1corrective intervention to
1000 h
0
1250
2500
3750
5000 h
•
No UV degradation over time (year, month,
week or day)
• Expected Lifetime = over 5000h
compensate degradation
Resulting in an unstable plate quality
production
29
Digital UV results in perfectly controlled
plate production
Conventional Banklight UV
Plate Surface
mm
mm
1200
1200
1000
1000
800
800
600
600
400
0
30
200
Energy Emmission from lamp to lamp
0
500
1000
1500
Each sq.inch receives exactly the
same light quality and quantity
400
∆ =10%
200
Simultaneous movement of the
UV source over the plate
mm
2000
0
0
500
1000
1500
mm
2000
•
Uneven light emission over the plate due to
individual lamp aging
• Uniform dot shaping
• Quality
of light emission is varying from
lamp to lamp
• Cool light – no heat distribution
Resulting in an unstable plate quality
production
Resulting in a predictable and consistent
plate quality production
plate
sleeve
throughout the whole
to plate or
31