Influencing Factors of Decrease in Wear Resistance of Printing Plates

The non-standard printing process will cause the printing plate to have insufficient printing resistance. During the printing process, it will be affected by many factors, causing the printing plate to be damaged and reduce its resistance to printing force:

1. Printing pressure: Printing pressure refers to the mutual force between embossed bodies in the printing process, which inevitably brings about compression deformation, speed difference and friction, and destroys the original structure and adsorption performance of the layout. The first is the roller pressure, which is the pressure between the plate cylinder and the blanket cylinder. If the pressure is too high, the friction between the printing plate and the eraser will be aggravated, and the sand on the surface of the printing plate will gradually wear out, making the dots of the printing plate graphic part Damaged, resulting in reduced printing plate resistance. Again, the pressure between the ink rollers, that is, the pressure between the ink roller and the water roller, especially the pressure between the platen roller and the plate roller and the plate, if the pressure between them and the plate is too large, Will increase the friction, so that the printing plate outlets are damaged, appear "off version."

2. Fountain solution: The purpose of the fountain solution is to maintain the balance between the blank part and the graphic part, protect the blank part of the printing plate from being invaded by the ink, and do not allow it to extend to the graphic part. In the printing, when the general printing ink film is 3pm, the water film is 1lAm to completely prevent the ink from expanding on the blank part. If the amount of printing plate fountain solution is too large, the phenomenon of ink emulsification is easy to occur, the density of the imprinted ink color cannot meet the requirements, and the corrosion degree of the printing plate base is deepened; the “plate stencil” or “stacking ink” of the printing plate affects the quality of the printing product.

3. Substrate surface appears rough, off the powder, pull the hair, sand and other paper contained in the printing process, these substances will increase the pressure, to accelerate the wear and tear of the printing plate graphics and reduce the printing plate resistance to printing force.

4. Some of the ink pigment particles are coarser, such as gold and silver powder inks and white inks. In the ink transfer process, the friction coefficient between the printing plate and the blanket is increased, and the wear of the graphic part is accelerated, resulting in a “flower pattern”.

5. The printing plate graphic part maintains enough remaining ink layers to prevent the graphic text from directly contacting the fountain solution and protect the graphic part of the printing plate. If the remaining ink layer in the graphic part is insufficient for a long period of time, the photosensitive layer is directly subjected to abrasion or acid-alkali erosion, which may easily cause a "flower pattern" phenomenon, which greatly reduces the printing plate's resistance to printing.

6. The effect of failure caused by printing machinery and equipment on the resistance to printing force: Part of the reason is closely related to the improper operation of the equipment. For example, due to improper installation of the machine, excessive printing speed, excessive printing pressure, vibration of the machine, and accelerated printing plate wear. The sleeve sleeves at both ends of the blanket cylinder are worn badly, causing the rubber cylinder to jump when printing, which will inevitably cause the printing plate to wear and reduce its service life.

7. Longer aging of the blanket, the rubber becomes harder and loses its elasticity, its capacity of the sense of fat drops, its ink transfer performance is poor, the ink of the printed matter is faded, and the printing plate wears out.