The generation and elimination of ink roller drop-off

In the field printing, besides the ink sheet, the ink roll falling-off material easily sticks to the ink layer. The main reason is that the ink roller is used for a long time and the wear is aged. In addition, due to the lack of attention to the maintenance of the ink roller, the product is not often scrubbed clean after printing, and the surface of the ink roller is aged and smooth, resulting in numerous cracks. Frequently, irregular black hard blocks are peeled off at the cracks, adhered to the surface of the printing plate, transferred to the blanket, and finally reflected on the ink layer of the printed product. The ink roller drop-offs are irregular triangles on the ink layer, black dots in the middle, and white circles around the drop-offs, which outline the shape of the drop-off.

Solution: There are two kinds of hard and soft ink rollers for inking parts. Hard ink rollers are generally ink rollers and metal is not easy to damage. Soft ink roller is mainly made of nitrile rubber, which is easy to expand and deform. , Dry surface conjunctiva or aging cracks, etc., affect the normal transmission of ink. In order to prevent the ink roller falling off from affecting the quality of the printed product, it is important to enhance routine maintenance and proper use.

1 The ink roller should always be kept clean and clean. After a product is printed, on holidays, the ink roller should be cleansed and wiped cleanly, leaving no ink and debris to avoid surface conjunctiva.

2 The aging of the ink roller is mainly caused by light and heat. Ink roller can not be placed in the sun, or near the hot gas, radiator, to prevent the aging of the surface, or ink stick softening. The ink roller is placed on the ink roller wooden frame when it is not in use, and it is in a dry and cool place.

3 Do not touch with non-volatile oils for a long time. Such as oil, varnish, butter, etc. should not be in contact with the ink roller for a long time, otherwise it is prone to swell and deformation of the roller surface.

4 The ink roller should avoid the phenomenon of rotten glue and dregs caused by the erosion of offset dampening fluid. Offset wetting fluid is a weakly acidic substance containing surfactants, wetting agents, emulsifiers and other substances. Do not fill the water tank with wetting fluid, or spill it on the ink roller or the water is too large. The wetting fluid chemical erodes the ink roller.

5 The method of eliminating the ink roll falling off is generally used artificial and mechanical grinding to remove the conjunctiva and rotten glue layer. However, pay attention to the diameter of the ink roller and do not polish it too much. If the ink roller is badly damaged by aging, it is best to replace the aging rubber roller and use a new ink roller to ensure the quality of the printed product.

Source: Printing Technology