JCTPRINT magnetic roller engineers share their experience: important factors affecting die-cutting quality

    There are many factors that affect the quality of die-cutting. This article will give you some common sense on the selection, use and maintenance of magnetic cylinders and flexible blades.

 

1. Why choose electromagnetic type for magnetic cylinder?

 

Answer: The magnetic cylinder uses high-strength permanent magnet blocks, high-quality steel and high-performance adhesive to ensure the stability of its long-term magnetic attraction function.

The magnetic cylinder composed of permanent magnet blocks is safe and reliable during rotary in-line die cutting. There is no need to worry about accidents caused by the sudden disappearance of electromagnetic force during high-speed operation, and the electromagnetic device is more complicated.

 

2. How strong is the magnetism of the magnetic cylinder?

 

Answer: After selecting high-strength permanent magnets that meet the standard, the normal magnetic cylinder and flexible knife skin can withstand the rotation speed of the rotary machine up to 300 meters per minute.

The magnetic cylinder has super-strength permanent magnets partially placed on the surface of the roller body, making the flexible blade edge stronger and able to withstand higher-speed rotary die cutting. However, the domestic blade has no coating technology and can only think about the material. Method, multiple choices are getting stronger and stronger to enhance wear resistance, but the adsorption force of the magnetic cylinder to the knife blade is getting worse and worse, and good imported knife blades are coated to make them more wear-resistant. The properties of iron remain unchanged so the adsorption force is stronger.

 

3. Will the magnetism of the magnetic cylinder weaken?

 

Answer: If maintained and placed properly, the magnetism will generally not weaken significantly within 10 years.

Some users' magnetic cylinders need maintenance after a few years. The reason is often not because the magnetic force of the magnetic cylinder is weakened, but because of the wear of the pillow shoulder and the magnetic cylinder body, or the roller is damaged due to improper placement of pressure during use. The shaft is bent.

 

4. Will the magnetism of the magnetic cylinder affect other parts on the die-cutting base?

 

Answer: The magnetic force of the magnetic cylinder only extends to a distance of about 10mm from the surface of the magnetic cylinder body, so it will not affect other components on the die-cutting seat.

Of course, when installing, try not to let the magnetic cylinder body come into contact with other parts, such as bearing sleeves, bottom rollers, etc.

5. Does the magnetic force of the magnetic cylinder become smaller as the diameter of the roller becomes smaller?

 

Answer: When the diameter of the magnetic cylinder is not less than the minimum recommended number of gear teeth, the magnetic force will not become smaller as the diameter of the roller becomes smaller.

But be aware that the diameter of the magnetic cylinder cannot be smaller than the minimum size recommended by the manufacturer.

 

6. Is there a limit to the minimum size of the magnetic cylinder?

 

Answer: The smallest and safest size recommended by the magnetic cylinder manufacturer is: the circumference of the roller is no less than the width of the machine. But if a smaller size must be used for various reasons, it is recommended to follow the 4:1 rule: the diameter of the roller should not be smaller than 1/4 of the width of the machine.

Although manufacturers can make rollers smaller than 4:1, following the above rules will prolong the life of the magnetic cylinder as much as possible in order to ensure smooth and even die cutting and avoid beating or even bending of the mold.

 

7. Will high temperature affect the magnetic cylinder?

 

Answer: The permanent magnet blocks of normal die-cutting magnetic cylinders can withstand temperatures up to 150 degrees Celsius. However, it is recommended not to leave it in an environment with high temperatures exceeding 80 degrees Celsius for a long time to avoid uneven surfaces due to expansion of the adhesive.

It should be noted that normal die-cutting magnetic cylinders cannot be used with hot stamping seats. The hot stamping magnetic cylinder needs to withstand high temperatures of at least 240 degrees Celsius.

 

8. Can the magnetic roller be repaired?

 

Answer: Yes, but it must be inspected by the manufacturer first. Depending on the wear and damage, the most common repairs are to replace the pillow shoulder, repair the roller body, correct the concentricity of the shaft, etc.