In the printing industry, especially in the flexographic printing process, the anilox roller plays a vital role. Its main task is to control and distribute ink, transferring the right amount of ink to the printing plate to achieve high-quality printing effects. In this process, an important parameter of the anilox roller is the "screen count", which directly affects the amount of ink transferred and the final quality of the printed product. For many printing operators and equipment technicians, understanding the screen count of the anilox roller and its role is the key to ensuring the quality of printed products.

This article will explain in detail what the screen count in anilox roller means and its impact on the printing process and quality.

What is the screen count?

The screen count (LPI, Lines Per Inch) refers to the number of mesh holes per inch of the surface of the anilox roller. These mesh holes are tiny grooves engraved on the surface of the roller by laser or other mechanical processing methods. They are responsible for absorbing ink and accurately transferring it to the printing plate. The unit of the screen count is "LPI" (lines per inch). The higher the value, the more mesh holes there are per inch, and the size of the mesh holes is relatively small.

Screen count is a key parameter to measure the performance of anilox rollers. It is closely related to the amount of ink transferred, the clarity of printing, and the overall printing effect. Different printing processes and needs have different requirements for screen counts, so choosing the right screen count is crucial to the printing process.

What is the common range of screen counts?

The screen count of anilox rollers is usually between dozens and thousands, and the specific value range depends on the required printing quality and application scenarios. The common screen count range is as follows:

    ● Low screen count (30-200 LPI): used for large-area printing that requires a lot of ink transfer, such as labels, large color block printing, and packaging printing.

    ● Medium screen count (200-600 LPI): suitable for general packaging printing and some medium-precision prints.

    ● High screen count (above 600 LPI): used for high-precision printing, usually seen in images and text printing that require extremely detailed details, such as high-quality labels and delicate packaging patterns.

The choice of screen count depends on the specific needs of printing, the type of ink used, and the required printing clarity.

What is the impact of screen count on printing results?

Screen count and ink transfer

The screen count directly affects the ink transfer volume of the anilox roller. The higher the screen count, the smaller the volume of each mesh hole, and the less ink it can hold; conversely, the lower the screen count, the larger the mesh hole, and the more ink it can store and transfer. This means:

    ● Anilox rollers with low screen counts are suitable for large-area printing that requires a thicker ink layer, such as printing large blocks of color or background colors. These prints usually do not require high clarity, but require high ink coverage.

    ● Anilox rollers with high screen counts are suitable for high-precision printing, such as detailed images, fine text and contours. Due to the smaller mesh holes, ink transfer is more precise, avoiding blurring, color block overflow or unclear images caused by excessive ink.

Therefore, when selecting anilox rollers, printing operators must adjust the screen count according to the characteristics of the printed product to ensure correct ink transfer and stable printing results.

Screen count and printing clarity

The screen count not only affects the amount of ink transfer, but also directly affects the clarity of the printed image. The higher the screen count, the finer the mesh on the surface of the anilox roller, and the richer the details presented on the printed product. Therefore, it is very important to choose an anilox roller with a high screen count when printing high-resolution images.

In contrast, anilox rollers with low screen counts are suitable for large-area ink transfer due to their larger mesh, but their clarity is relatively poor. Therefore, this type of screen count is usually used for rough printing or large color block printing projects with low requirements.

For example, when printing large blocks of color or backgrounds, a lower screen count can effectively reduce the problem of ink accumulation during the printing process and ensure a smooth printing surface. When printing small text, delicate patterns or gradient effects, anilox rollers with high screen counts can ensure the fineness and consistency of printing.

What are the criteria for selecting screen counts?

Selecting screen counts according to printing type

When selecting screen counts in printing processes, the following key factors usually need to be considered:

    ● Printing materials: Different materials have different properties for ink absorption and diffusion. Smooth surfaces such as plastic film, metal foil and other materials usually require an anilox roller with a high screen count to ensure accurate ink coverage; while rougher or oil-absorbent materials such as paper or cardboard usually use an anilox roller with a lower screen count so that enough ink can penetrate the surface.

    ● Printing pattern accuracy: The more details and the more complex the image, the more you need to use an anilox roller with a high screen count to ensure the clarity of the image and text. If you are printing simple patterns, logos or large blocks of color, an anilox roller with a low screen count may be more suitable.

    ● Ink type: The viscosity, drying time and surface tension of the ink will affect the choice of screen count. Thinner inks tend to flow out of large mesh holes, so a high screen count anilox roller is needed to control the transfer of ink. For thicker inks, a lower screen count anilox roller can be used to ensure sufficient ink transfer.

Screen count selection for different printed products

    ● Label and packaging printing: Packaging printing usually requires a certain degree of precision, but ink coverage also needs to be considered, so medium screen count (200-400 LPI) anilox rollers are often used. Higher screen counts can ensure clear printed patterns, but adjustments must also be made based on the characteristics of the material and ink.

    ● Detailed image printing: High-resolution images, gradient effects, and fine patterns usually require anilox rollers above 600 LPI. High screen counts ensure that every detail can be accurately presented, suitable for high-quality printing requirements.

    ● Large-area color block printing: Low screen count (30-200 LPI) anilox rollers are suitable for large-area color block printing, especially in applications that require heavy colors such as advertising posters and packaging backgrounds. Low screen counts ensure that each print provides sufficient ink coverage.

What is the relationship between screen count and other anilox roller parameters?

Screen count and mesh volume

The screen count and mesh volume are interrelated parameters. Generally speaking, the higher the screen count, the smaller the mesh volume; conversely, the lower the screen count, the larger the mesh volume. This relationship directly affects the amount of ink transferred.

    ● High screen count and small mesh: The mesh surface of the high screen count anilox roller is smaller, and the ink storage capacity is less, but it can provide more precise ink control. This type of anilox roller is suitable for printing images and text with rich details.

    ● Low screen count and large mesh: The mesh of the low screen count anilox roller is larger, and the ink storage capacity is relatively large. It is suitable for printing large areas of color, especially in printing tasks that do not require high details.

Relationship between screen count and ink type

Different types of inks have different requirements for screen count. Generally speaking, thinner inks are suitable for high screen count anilox rollers because smaller mesh holes can better control the amount of ink transferred and avoid excessive overflow. Thicker inks require low screen count anilox rollers because large mesh holes can store more ink and ensure adequate coverage.

How to test and maintain the screen count of anilox rollers?

Testing the screen count of anilox roller

When selecting and using anilox rollers, it is very important to ensure that the screen count meets the requirements. By using a magnifying glass or other measuring tools, the screen count of the anilox roller can be tested to ensure that its accuracy meets the printing requirements.

Maintenance of anilox rollers

The anilox roller needs to be cleaned and maintained regularly to ensure that its screen count and mesh remain accurate. Impurities such as ink residue and dust can easily clog the mesh, thereby affecting the ink transmission effect. Therefore, regular cleaning and maintenance of the anilox roller helps to extend its service life and ensure the stability of printing quality.