What is a doctor blade in printing?
Doctor blades control the quantity of ink that is transferred onto the printing cylinder. They do this by removing excess ink from the cylinder surface as it rotates and supplies ink. In essence, they act as metering blades.
What is doctor blade used for?
The function of the doctor blade is to remove ink or coating from the surface of the engraved gravure cylinder or flexo anilox roll so that the only ink or coating remaining on the cylinder is that which is contained in the engraved cells.
What is doctor blade material?
The doctor blade is a relatively cheap and disposable consumable, while the gravure cylinder or flexo anilox is a more expensive component of the press. Typical materials for the blade are steel or polymer: gravure cylinders are normally hard-chrome plated and flexo aniloxes may be chromed or ceramic.
What is doctor blade method?
common tape-casting method is called doctor blading. In this process a ceramic powder slurry, containing an organic solvent such as ethanol and various other additives (e.g., polymer binder), is continuously cast onto a moving carrier surface made of a smooth, “no-stick” material such as Teflon.
What is a doctors blade called?
While there are many methods of printing, there are two predominant methods that use Doctor Blades. They are called Rotogravure (gravure), and Flexographic (flexo) printing. In both Gravure and Flexo printing, the doctor blade is technically a metering blade.
Is a chemical damage to the doctor blade?
Blade wear can have three different causes: abrasion (commonly produced by foreign particles or the use of abrasive ink pigments), fatigue (caused by stress), and corrosion (the result of chemical reaction, such as oxidation—or rusting—or overly acidic or alkaline ink vehicles).
What is flexographic printing process?
Printing A flexographic print is made by creating a positive mirrored master of the required image as a 3D relief in a rubber or polymer material. Flexographic plates can be created with analog and digital platemaking processes. The image areas are raised above the non image areas on the rubber or polymer plate.
What is a doctor roll?
[′däk·tər ‚rōl] (chemical engineering) Roller device used to remove accumulated filter cake from rotary filter drums.
How does a flexographic printer work?
How Does Flexography Work? In flexographic printing, the starting material comes in the form of a roll, which passes through a series of rotary flexible relief plates. A specialized roller feeds each flexible plate with ink, with a single flexible plate required for each individual printed color.
How do you set up Dr Blade?
Ideally, the contact angle should be 30° tangent to the anilox roll circumference. In reverse angle and chamber blade applications, the doctor blade angle should be between 28° and 32°. If the blade angle drops below 28°, a larger part of the blade’s edge will come into contact with the roll.
What is a doctor blade used for in printing?
In printing the doctor blade (from ductor blade) removes the excess ink from the smooth non-engraved portions of the anilox roll and the land areas of the cell walls. Doctor blades are also used in other printing and coating processes, such as flexo and pad printing for the same function.
What is the best doctor blade for flexo printing?
The FlexoTip doctor blade was specially developed for flexo printing and offers two major advantages when used in chamber doctor blade systems. On the one hand the 30 ° setting towards the anilox roller and on the other hand the FlexoTip-bevel angle. This one is rounded by 30° on both sides, which makes installation much easier.
What makes a good doctor blade?
In general, a thinner blade edge allows for a cleaner wipe. Equally important for good doctor blade life is the relationship between cell configurations (shape/count) and blade tip thickness. Daetwyler manufactures a variety of doctor blades designed for maximum lifetime to meet your specifications and applications.
What is a combi doctor blade?
Combi doctor blades are specially designed for gravure printing. One of the biggest issues for many gravure printers is the premature wear of lamella doctor blades due to damage in the areas around the cylinder edges. TKM has developed the combi doctor blade as a suitable solution.