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Concentric Screening. Commonly used Screening. Amplitude Modulated screening. Modulates the screen area by changing the size of halftone dots. To get darker colors, the process uses larger dots — a larger amplitude

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Presentation Transcript
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Amplitude Modulated screening

  • Modulates the screen area by changing the size of halftone dots. To get darker colors, the process uses larger dots — a larger amplitude
  • This has been the typical method for creating halftones and process screens for the last 100 years or more.
  • Acceptable dot gain
  • Smoothness
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Frequency Modulated screening

  • Modulates the screen area by changing the number of randomly distributed dots of the same size that appear in a given area.
  • Can solve registration issues
  • Has fine Detail
  • Better press stability
  • Good color saturation
  • Ink Savings
  • More stringent process control
  • Grainy midtones and vignettes rather than a smooth gradation in tone.
  • Buildup of ink or paper residue on the printing press blanket
registration sensitivity
Registration Sensitivity

150 lpi - AM

20µ Stochastic

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Screen Visibility

The smoothest pattern is uniformly spaced

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smoothness

Screen Visibility

concentric screening
Concentric Screening

Conventional Dot

Concentric Dot

rings limit ink film thickness
Rings Limit Ink Film Thickness

175 lpi “Normal” Dot

175 lpi Concentric Dot

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Screen Visibility

FM

Concentric

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175 lpi Round

175 lpi Concentric

175 lpi round
175 lpi Round

310 lpi Concentric

press stability

90,00%

80,00%

70,00%

AM 25%

60,00%

Concentric 25%

AM 50%

50,00%

Concentric 50%

Percentage in print

40,00%

AM 75%

30,00%

Concentric 75%

20,00%

10,00%

0,00%

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Sheets

Press Stability
best of both worlds
Best of both worlds

• Greater color saturation

• Greater press stability

• Ink savings (10%-35%)

• Higher screen rulings

• More detail than AM

• Smoother than FM

real world learnings
Real World Learnings

Plate imaging is more critical

Printing is more stable

but … the color is different.

technical assesment plate imaging
Technical Assesment : Plate Imaging

1. Use premium plate material

2. Optimize processing

3. Optimize laser focus

4. Optimize laser intensity

5. Optimize beam alignment

6. Calibrate your plate

real world learnings today s printer struggle
Real World Learnings: Today’s Printer struggle

Quality Materials Ink Prices

Operational Cost Printed Volume

benefits quality
Benefits: Quality
  • Quality is nr 1 pain, due to decreasing quality paper and ink. Daily fight to keep the printing process under control.
  • Customer quote: the best thing that I like about Concentric is the fact that my customers don’t see anything related to screening, but notice an improved quality.
benefits reduce ink consumption
Benefits: Reduce ink consumption
  • Cost reduction: ink prices increased 30% in 2008, ink represents up to 17% cost of printed job.
  • Less ink means less wash intermediates: time + cost savings & waste reduction
benefits reduce ink consumption1
Benefits: Reduce ink consumption

1 Manroland LithoMan 48 pag presses operating in 3-4 shifts, 50-60.0000 copies/hour

  • Ink consumption:

500.000 kg

  • Cost: @ 3 € per kg

1.500.000 €

  • Savings 15%

220.000 €

benefits reduce wash intermediates
Benefits: Reduce wash intermediates

Why wash?

Blanket cylinder gets polluted by f.i. paper particles

Paper particles are picked from the paper by ink

Less ink = less particles

Less particles = reduction of wash intermediates

After every 50.000 copies or approximately 1 hour of printing there is a wash

intermediate that takes a few seconds... No big deal?

Washing cycle:

The machine reduces speed to 30.000 copies an hour

The press stops printing, the paper continues its travel trough the press into

the waste container...

The whole wash sequence takes 2 minutes

1.000 signatures are thrown away, no matter what size the press, every hour,

day in, day out

benefits reduce wash intermediates1
Benefits: Reduce wash intermediates

Feedback from reference site :

Heatset Presses

  • 2 x 64pp presses.
  • 6 x 48pp presses.
  • 1 x 16pp press.

Coldset Presses

  • 2 x 64pp presses.

Quote: “We have decreased our wash intermediates, we print

60.000 copies instead of 50.000 copies”.

In practice: 4 wash intermediates less per day

benefits reduce wash intermediates2
Benefits: Reduce wash intermediates

2 minutes at 30.000 signatures/hour = 1000 signatures

1 signature = 1.62 m2

1000 signatures = 1620 m2

Paper weight: 60 gr/m2

Paper waste in 2 minutes = 97.2 kg.....every hour!

benefits waste reduction
Benefits: Waste reduction

Without Concentric Screening:

24 wash intermediates x 97.2 kg = 2330 kg paper waste per day

With Concentric Screening:

20 wash intermediates x 97.2 kg = 1944 kg paper waste per day

2330 - 1944 = 356 kg per day

WASTE: yearly (200 x 356 kg) = 71.200 kg

benefits
Benefits
  • Quality
  • Ink Savings
  • Reduce wash intermediates > Waste reduction
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