The eight coups teach you how to determine the quality of the blanket

Offset printing belongs to indirect printing. It transfers the graphic information of the printing plate to the blanket, and transfers the graphic information to the printing material through the pressure between the blanket and the impression cylinder. Therefore, the quality judgment of the blanket becomes an important part of the quality control of the offset printing. The quality of the blanket needs to consider the following aspects.

elasticity

The more elastic the blanket, the stronger its instantaneous resilience, the more it can adapt to high-speed printing, the better the dot reducibility, the more it can truly reproduce the original.

2

Surface roughness

The higher the surface flatness of the blanket, the better the dot reduction performance.

3

Roughness

If the surface roughness of the blanket is large, the paper-leaving property may be superior, but the solid printing density may be unstable, and dot dot enlargement may easily occur, and the printing contrast may also increase. Therefore, the surface roughness of the blanket can affect printing properties such as paper release, solid density, dot change, and print contrast.

4

Responsiveness

Long-term use of the blanket is prone to permanent deformation due to compression fatigue, resulting in a change in the thickness of the blanket. If the blanket has good recovery, the change in thickness is small and the life cycle is long. Therefore, the resilience of the blanket directly affects the use of the blanket. life.

5

Stretchability

On a sheet-fed offset press, the blanket is stretched on the blanket cylinder and stretches in the circumference of the cylinder. The good stretchability of the rubber band becomes small, and dot reduction and overprinting effect are good.

6

Antioxidant

In the process of cleaning the blanket, the car wash water and the like easily penetrate from the edge of the blanket, resulting in uneven edges of the blanket, especially when kerosene, gasoline, etc. are used to clean the blanket, and the damage to the blanket is greater, so the blanket is Oxidation resistance is also a determinant of its life span.

7

Oil and solvent resistance of surface layer

During the printing process, the ink will permeate into the surface layer of the blanket. If the rubber layer on the surface of the blanket is resistant to oil and solvent, it will be easier to clean and the ghost phenomenon will be weaker. Otherwise, it will not be easy to clean. The blanket will make the ghost phenomenon more serious.

8

Resistance to force

The resistance of the blanket is determined by the elasticity and hardness of the blanket. As the elasticity increases, the resistance of the blanket will gradually increase, but when the elasticity of the blanket reaches a certain value, the stability of the blanket will decrease, thereby affecting the stability of the printed dot. After testing, when the hardness of the blanket is around 81HA, the resistance force is ideal.

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