Doctor blades have been used in printing for many years. Your printing kit is incomplete without a doctor blade. The quality of your printing depends on it. But for a pressroom it is important to know how to choose the right doctor blade?
What factors should be considered to assure precise efficient metering? To answer these questions, we must understand the fundamentals of ink transfer, especially as it relates to minimizing the anilox ink film.
Why a good doctor blade is crucial for good printing?
The core purpose of a doctor blade is to remove excess ink from an anilox roll’s surface.
When you use a doctor blade, you can ensure that the pressure is applied evenly to remove excess ink from an anilox roll’s surface.
How to choose the right doctor blade?
You should choose a doctor blade that is specifically designed for the machine model and intended use of your machine, as there are many types on the market. Flexographic printing professionals will be able to help you with this in most cases.
It is important to consider three factors: material, thickness, and opening size.
Typical materials for the blade are steel and normally hard-chrome plated and thicknesses vary from 0.150 to 0.500 mm.
Opening size depends on the contact area between the blade and anilox roll. This should be kept to a minimum to to remove excess ink from an anilox roll’s surface.
How do you know it’s the right blade for your machine?
In choosing a doctor blade for flexographic printing, there are several factors to take into consideration, such as the print medium and print resolution.
To get started, it’s important to understand the various print media options available. Flexo film is the most common type of printing media, and it is used in magazines, catalogs and other large-scale printing applications.
When it comes to achieving minimum blade to anilox roll contact area, the actual blade contact area is determined by thickness of the doctor blade and blade edge.
Doctor blade edge profile
The edge profiles available for doctor blades include round edge, bevel edge, and laminate edge.
Round Edge
A double-sided radius edge profile ensures smooth contact at high speeds. Provides a high quality seal between the blade and the roller.
Bevel Edge
Maintains a constant edge for clean doctoring and reduced wear. The bevel angle can be adjusted to suit exact requirements (typically 2 – 30 degrees)
Lamella Edge
Precision ground for a high quality profile finish. Provides a constant contact area with lower friction and reduced wear. Lamella profile produced according to exacting requirements.
Advantages and disadvantage of the doctor blade:
You should consider the advantages and disadvantages of using a doctor blade when printing. Doctor blades are known for their accuracy and speed. Prints can be produced quickly and accurately with high quality.
A disadvantage of the doctor blade is that it wears down quickly, which affects the performance of the printer. Other disadvantages include the cost of the blade and the need to replace it frequently.
Conclusion:
Choosing the right doctor blade for your flexo machine can be a little bit of a challenge. Not only do you need to decide which type of machine you have, but you also need to consider the specifications of that particular blade. In the end, choosing the wrong doctor blade can damage your machine and lead to frustrating printing experiences. So if you’re not sure what type of doctor blade is best for your specific printer, don’t hesitate to consult the manufacture of your machine and your technical team.
Read next about How does my anilox roll affect my print.
You can find the right doctor blade for your flexo printing at Anyflexo Marketplace.