Blanket plays an important role in offset printing and is mainly used for ink transfer. However, customers often encounter difficulties in their use. As a printing specialist, the Manroland Material Department provides practical experience and hopes to solve problems for customers.
Choose a quality blanket
The first thing to do is to choose a blanket. If you choose an inappropriate blanket, you will not only shorten the life of the blanket, but also affect the quality of the printing, waste time and money, and ultimately lead to customer losses. When choosing, pay special attention to the following 5 points:
1. Is the aluminum clip factory-processed?
2. How flat is the blanket and is there a thickness tolerance?
3. How effective is the dot restoration?
4. Is the ink transferable?
5. How is the blanket stretch rate? (The smaller the blanket extension rate, the better. Generally, the ductility of the blanket is about 2.1-2.5%.)
The correct installation method of blanket
The method of installing the blanket properly is equally important. If the installation is not allowed, the printing effect will not only be greatly reduced, but the printing machine may also be immediately reimbursed. The operator’s general mistake is excessive torque and tearing the blanket along the edge of the aluminum clip.
It should be noted that when the torque is sufficient, the torque wrench will only send a signal, but will not prevent you from adding more torque. Therefore, when you hear the torque wrench signal, you should stop tightening the blanket again.
The correct installation method is to first install the blanket on the drum. It is recommended to use the torque 100Nm. After hearing the signal of the torque wrench, immediately stop tightening the blanket or increase the torque. After running 3000 and 10000 rpm, tighten the blanket and, similarly, stop tightening the blanket after hearing the torque wrench signal.
Always check the pressure of the blanket, the surface of the blanket, and the thickness of the lining if they are average and correct.
The best care for blankets
1. To properly regulate the pressure between the plate and the blanket
2. Must properly tighten the blanket
3. Avoid excessive pressure between blanket and impression cylinder
4. Clean the blanket only when necessary
5. Use a compatible cleaner
6. Do not let the ink dry on the blanket
7. Avoid heat, direct sunlight, and excessive temperature
8. Do not enter paper with tear angles, folds, and creases
9. Regularly check and replace gun bottom paper and bottom glue. And please use the appropriate bottom paper, avoid using ordinary printing paper.