First, the use of blankets

　　 1 the characteristics of the blanket and how to set the thickness of the lining?
"Condi" blanket is the third generation of blankets invented in the 1990s. It is a closed type rubber particle that is uniformly added to make the internal pressure higher than the external pressure of the printing in the vulcanization process of the rubber, so that under the pressure of the printing, the closed type The rubber interior only changes its shape and volume without a process of inhaling and exhausting. It can be satisfied with high-speed printing and over a certain limit from overpressure under abnormal conditions. This will not only make the dots clearer. The head can make most of the small area printing in a large area of ​​printing without having to replace the blanket.

Due to the good elasticity of the air cushion of the “Candidi” air-cushioned blanket, the coefficient of sagging of the blanket is 0.05mm to 0.1mm less than that of other branded blankets (the dip coefficient refers to the difference between the thickness before blanket printing and the thickness after printing). Value) In this way, if you use other brands of blankets to replace the "Condi" blanket, you must consider this difference in the calculation of the lining, (indicating that the PS roller and the blanket roller and the blanket and the impression roller In the case of intermediate pressure) because the requirement of blanket lining is within the error range of 0.015mm, the overpressure generated by it is far from 0.05-0.1mm, resulting in the expansion of dots, which cannot be changed when small area is printed. Area, blankets difficult to clean and other issues.

2 the selection of the bottom of the gun?

With the development of society and printing technology, the selection of bottom papers for blankets has become more and more popular, because not only the thickness of 0.01 to 0.02 mm is present in the thickness of each ordinary coated paper, but also changes with temperature and humidity. , When at different times and under different climatic conditions, the superposition of multiple ordinary coated papers causes great errors. You only need to test whether the total thickness of the paper before the machine is within the error range of 0.02mm, to meet your printing requirements or use special gun-end paper.

3 withdraw the liner under the condition of ensuring the printing pressure

Since the printing press can adjust the printing pressure according to different paper thicknesses, the distance between the impression cylinder and the blanket cylinder can be adjusted. The distance between the blanket cylinder and the PS plate cylinder does not change after the equipment is installed. The pressure between them is provided by the machine manufacturer, because the manufacturer designs the rubber rollers on the roller and the PS. The pressure between the plate cylinders is set on the PS platen roller so that the blanket cylinders only need to be placed on the platen with the roller platen during printing. (Because in the printing, the rubber blanket will produce rubber pressure coefficient after 20 weeks of rotation, so when installing a new blanket, the general high dry roll pillow 0.05mm).

The elasticity of the "Kandy" blanket is good, and the pressure coefficient is small. Generally, the new blanket thickness is 1.95 or 1.69mm, and the pressure coefficient is about 0.04mm. However, some blankets are only 1.88mm thick or 1.61mm thick. We guarantee the blanket cylinder. With the case of PS platen roller pressure, it is reasonable to consider the thickness difference between different brands of blankets to calculate the thickness of Baocun to achieve perfect printing.

Attachment: Lining Thickness for Various Models of Printing Machines When Using Condé Rubber Blanket (Reference)

Printer model

Lining thickness

Printer model

Lining thickness

Heidelberg 102V/CD102V

35 wire

Roland 700

65-68 wire

Heidelberg SM74/72

35 wire

Komori 40

85 wire

Heidelberg SM52

100 wire

Mitsubishi 3F/IF

40 silk (neutral)/50 silk (when no shot film is used)

Heidelberg GTO52

105 wire

For other unprinted press models, the thickness of the lining when the other brands of blankets are normally used is subtracted by 5 wires.