Flexibility of Printing Materials in Flexible Printing and Its Variables

When it comes to printing plates , the distinction between folding carton printing, label printing, flexible packaging printing, and corrugated paper direct printing must be understood. In these printing productions above, in order to further improve the printability of inks and substrates, relatively thin printing plates are often used. In flexographic printing, the printing pressure is always higher than the kiss-print printing pressure. Therefore, the printing plate will inevitably inevitably occur ------- deformation, resulting in an increase of points, and may lead to the lake version. In order to increase the resolution of the printing plate, reduce the increase of the outline point and increase the printing speed, the thin printing plate is often installed on the elastic pad material. It should be remembered that the softer the printing plate, the higher the increase of the outline and the more important the paste version.

The higher the number of printing plate lines, the greater the increase of the outline points. In order to obtain repeatable good printing results, some media were selected as standard media to ensure that the printability of the paper was improved.

Print on coated paper
For flexible packaging printing on coated paper, a nyloflex FAH or FAR type II plate with a thickness of 1.14 mm is often used, and a foam-coated sleeve is provided, and an anvil roller and an ink hole are also provided. Squeegee. The elastic plate on the sleeve allows the actual site to be subjected to a greater printing pressure, eliminating the perforations, and on the other hand the half-tone area can be subjected to a smaller printing pressure, resulting in a clear circular outline. When the ink is set in place, the ink transfer amount of the roller can ensure that the solid part of the ink is full, as long as the FAH plate with a thickness of 1.14 mm is used (with a sleeve with a foam coating, the solid and outline patterns can be printed ) It is also easier to add a bar code to the actual or half-colored part of each plate. When printing on coated paper, the thickness of the plate is usually 1.14 mm. The hardness of FAH media is Shore A (grade A, different) 56-58, while the hardness of softer FARII media is Shore Hard 49-52. Both of the above plates can be used to print graphics on coated paper.

Print on non-coated paper
Do not configure the sleeve
The surface roughness of this substrate has a great influence on printing. When printing on rough paper, use a 2.25 mm thick plate. The FARII254 plate is to be mounted on PE or PU double-sided elastic mounting tape. These mounting tapes are hard and soft. The harder the mounting tape, the better the printing effect. When printing on uncoated paper, harder mounting tapes are generally used. Plates with a thickness of 2.54 mm were equipped with a PU or PE mounting tape with a thickness of 0.50 mm or 0.55 mm. The printing plate with a thickness of 2.84 mm has a high rate of increase in the outline, and its use is gradually decreasing.

Configuration sleeve
FA1.2, FARII, or FAH plates with a thickness of 1.70 mm can also be used when configuring sleeves. The configured sleeve should be a hard sleeve, and the following is a mounting tape with a thickness of 0.38 or 0.55 mm. The sleeve should be custom made according to the thickness of the mounting strip used. When printing on uncoated paper, it is best to use a relatively soft plate (such as nyloflex FARII or FA plates) because of the high hiding power of the soft plate and overprinting inks. On small rollers, FAII plates are less rigid because they are less rigid.

Print on corrugated cardboard
To significantly reduce the increase in outline printed on corrugated paper. The FAC394 plate was introduced with a thickness of 3.94 mm and was mounted on an inert R/back-type mat. FAC394 profiles are kraft boxboard printing plates. The relief height is typically 2-3 mm. Two different plates can be used depending on the weight of the board. The FAC394 type plate with a Shore hardness of 32-34 is normally used when printing on uncoated white paperboard and Kraft board B wave, which can eliminate the possible adverse effects due to surface roughness.

However, when printing on white paperboard and kraft paperboard, Asian printers are more and more inclined to use harder plates (such as the FACII394S type plate with a Shore hardness of 40-42). It is said that this kind of plate outline has a smaller increase, the printing effect is clear, and it is easy to handle. To prevent crushing the corrugations, the printing pressure must be set carefully. When printed on coated and semi-coated white paperboards (European weight 180-220 g/m2), BASF nyloflex FAII type plates with a thickness of 2.84 mm or 2.54 mm are increasingly used today. material. This plate has a Shore hardness of 44-46, a minimal increase in outline, and a high print quality in halftone text.

A 4.05 mm thick elastomeric mat was used for plate mounting. These plates are usually mounted on a 1mm thick tape and PET padding is used to achieve the best compressible state of the pad material. Then the PET pad material is fixed on the R/bak material. Then install it on the roller. This is a form of loading that is often used in Asian printing.

Source: Paper Easy