Troubleshooting

With its extensive expertise and tremendous commitment, Daetwyler SwissTec has efficiently tackled every challenge, including in your printing environment. Click here for a list of existing solutions to your printing issues.

Issues with flexo printing
Issues with gravure printing

MDC doctor blades help avoid all manner of issues including ink spitting, bleeding, dot loss/gain, ghosting effect, uneven ink layer, streaks and chattering marks.

Bleeding

Bleeding

Ursachen

Humidity is too high – water is condensing in the sovent-based ink
Amount of retarder used is excessive
Ink viscosity is too low
Pick-up volume is too high
Print speed is too high

Lösungen

Mix fresh ink
Use an ink with a faster solvent
Adjust the viscosity
Replace the anilox roller
Reduce the print speed – increase the drying capacity
Even though the doctor blade is not the decisive element, we recommend sharp doctoring
Use bevel or lamella configuration
Use coated doctor blades

Ink spitting

Ink spitting

Ursachen

Doctor blade has entered the area of the cylinder edge
Surface of the anilox roller is damaged or dirty
Wrong ink temperature

Lösungen

Replace the doctor blade
Look for dried ink at the edges of the cylinders
Check the cylinder radius
Adjust the ink temperature

Product suggested

PEARLSTAR

LONGLIFE PRO

SOFT

LONGLIFE

Vertical streaks

Vertical streaks

Ursachen

Doctor blade is worn
Dried ink in the chambered doctor blade system
Anilox roller is dirty or ink has dried on the anilox rolle
Particles in the chambered doctor blade system

Lösungen

Replace the doctor blade
Clean the chamber
Install an ink filter

Product suggested

LONGLIFE PRO

SOFT

LONGLIFE

Horizontal streaks

Uneven ink layer

Uneven ink layer

Ursachen

Ink viscosity is too low
Too much retarder inside the ink
Substrate surface is uneven
Incorrect doctor blade pressure

Lösungen

Add fresh ink and fresh varnish
Reduce retarder in your ink
Use softer printing plates
Check and adjust doctor blade pressure

Product suggested

LONGLIFE PRO

SOFT

LONGLIFE

Ghosting effect

Ghosting effect

Ursachen

Pick-up volume of the anilox roller is too low
Ink is drying in the cells
Cells are inadequately filled
Print speed is too low

Lösungen

Use an anilox roller with a higher pick-up volume
Add retarder to the ink
Increase the pressure in the chambered doctor blade system
Increase speed or ink viscosity

Product suggested

LONGLIFE PRO

SOFT

LONGLIFE

Ink density is too low

Ink density is too low

Ursachen

Ink dries on the anilox rolls
Ink is too thin
Ink is faulty
Anilox rollers is worn out and the volume is too low
Low pressure between the plate cylinder and the print substrate
Low pressure between the anilox roller and the plate cylinder

Lösungen

Clean the anilox roller
Increase the viscosity of the fresh ink
Change the anilox roller
Replace them with fresh ink
To increase ink strength, use a lamella doctor blade with a larger contact area
Adjust the printing pressure settings

Product suggested

LONGLIFE PRO

SOFT

LONGLIFE

Dot gain

Dot gain

Ursachen

Excessive pressure between the plate cylinder and the substrate
Doctor blade lamella contact zone is too big
Temperature of the central cylinder is incorrect
Excessive pick-up volume

Lösungen

Reduce pressure and adjust pressure setting
Reduce the doctor blade contact zone in relation to the anilox roller
Check the temperature of the central cylinder
Check the anilox roller with the manufacturer

Product suggested

LONGLIFE PRO

SOFT

LONGLIFE

Ink density is too high

Ink density is too high

Ursachen

Volume of the anilox roller is too high
Ink viscosity is too high
Ink formulation in colour matching is too strong

Lösungen

Use an anilox roller with reduced volume
Add solvent to adjust the ink viscosity
Add blend and ajust the ink recipe
Use a lamella doctor blade with a thin contact zone

Product suggested

LONGLIFE PRO

SOFT

LONGLIFE

Halo effect

Halo effect

Ursachen

Volume of the anilox roller is too high
Pressure in the blade chamber system is too low
Pressure between plate cylinder and substrate is to high
Pressure between anilox roller and plate cylinder is too high

Lösungen

Choose anilox roller with reduced volume
Reduce pressure and adjust pressure settings
Increase pressure in the blade chamber system
Use a lamella doctor blade with thin contact zone

Product suggested

LONGLIFE PRO

SOFT

LONGLIFE

Other problems?

In combination with the right set-up, the MDC doctor blades can help avoid all manner of printing issues including hazing, unsmooth gradients, drag outs, flaws, chattering marks, ink streaks and spots.

Hazing

Hazing

Ursachen

Blade angle is too flat
Excessive blade pressure
Ink is not drying fast enough
Incorrect roughness of the printing cylinder

Lösungen

Increase the blade angle
Use a lamella doctor blade with a thin contact zone
Check doctor blade pressure
Check distance of support blade to doctor blade tip (max. 5 mm)
Add accelerator and check the viscosity
Check the roughness of the cylinder
Dechrome and rechrome the cylinder

Hazing in printing process

Product suggested

OPTILIFE

LONGLIFE PRO

LONGLIFE

Unsmooth gradient

Unsmooth gradient

Ursachen

High ink viscosity
Incorrect screen or cell geometry
Cylinder temperature too high
Press room temperature too high
No electrostatic assist system (or not working)

Lösungen

Check ink viscosity
Discuss screen or cell geometry with cylinder manufacturer
Check cylinder and ambient temperature
Reduce doctor blade angle slightly
Check electrostatic assist system (ESA)

Drying up

Chattering marks

Chattering marks

Ursachen

Ink is collecting under the blade
Blade angle is not set correctly
Main cylinder gearbox is not running out smooth
Doctor blade pressure too low
Doctor blade is loose in the blade holder (check installation)
Doctor blade holder is loose or vibrating

Lösungen

Reduce the printing speed
Set the doctor blade angle to 60° to 70°
Check the main cylinder gearbox for concentricity
Check oscillation of doctor blade holder
Tighten the blade and holder adjusting screws
Correct blade installation
Pay attention to cleanliness
Use support blades

Chatter marks in printing process

Product suggested

LONGLIFE PRO

LONGLIFE

SOFT

Drag outs

Drag outs

Ursachen

Upper side of the lamella is contaminated with dust or particles
Ink viscosity is too low

Lösungen

Clean the doctor blade (wipe off with a pointed wooden stick)
Increase the ink viscosity
Use an ink filter

Drag outs in printing process

Product suggested

OPTILIFE

LONGLIFE PRO

LONGLIFE

Ink streaks

Ink streaks

Ursachen

Ink contains colour particles
Ink filter not being used
Doctor blade contact zone is damaged
Cylinder surface roughness and/or grinding pattern is wrong

Lösungen

Clean the doctor blade (wipe off with a pointed wooden stick)
Use ink filter
Replace the doctor blade
Check the surface roughness and/or grinding pattern
Check and adjust the ink viscosity

Ink streaks in printing process

Product suggested

OPTILIFE

LONGLIFE PRO

LONGLIFE

Missing dots

Voids (spots)

Cylinder wear

Cylinder wear

Ursachen

Uncoated doctor blade in use
High blade pressure
Flat blade angle
Non-optimal surface roughness of the cylinder

Lösungen

Use coated blades
Increase angle of the blade and reduce blade pressure
Adjust blade set-up to reduce blade deflection
Adjust the roughness of the cylinder or rechrom

Daetwyler SwissTec Problemlösung von Verschleiss

Product suggested

OPTILIFE

LONGLIFE PRO

LONGLIFE

ROTOSTAR

Other problems?

Doctor blades for
gravure printing

Doctor blades for
flexo printing

Doctor blades for special applications

Partner in your area

Daetwyler SwissTec

Daetwyler SwissTec

The market leader in the printing industry provides MDC doctor blades for flexo and gravure printing and special applications. The world-famous MDC Longlife has been the best doctor blade on the market for many years.

More about Daetwyler SwissTec

To the Daetwyler Group website

To the Daetwyler USA website

Our Head Office

Daetwyler SwissTec
Flugplatz
3368 Bleienbach
Switzerland
[email protected]
+41 62 919 31 31

Contact form

Step

Last name *

First name *

Company *

Country *

E-Mail *

Message

I agree to the storage and processing of my personal data by Daetwyler SwissTec. *

Input *