Using Magnetic Rollers and Flexible Blades Frequently Asked Questions

Description: Many users still have questions about how to properly use and maintain magnetic rollers and flexible blades. The following questions and answers are summarized in the Asia-Pacific region, many trademark manufacturers, many years of use of magnetic roller and flexible blade often encountered and raised questions and answers.

Q: Is the magnetism of the magnetic cylinder electromagnetic and can be turned on and off?

A: Magnetic rollers use high-strength permanent magnets, high-quality steel and high-performance viscose to ensure long-term magnetic stability. The magnetic roller constituted by the permanent magnetic block is safe and reliable in the die cutting of the rotary connection line, and does not have to worry about the sudden disappearance of the electromagnetic force to cause an accident at the time of high-speed operation.

Q: How strong is the magnetic force of the magnetic roller?

A: After selecting a high-strength permanent magnetic block that meets the standard, normal magnetic rollers and flexible blades can withstand rotation speeds of up to 300 meters per minute. Rothley magnetic cylinders place a super-strength permanent magnet on the surface of the roll body to make the lap of the flexible blade firmer and withstand higher-speed rotary die cutting.

Q: Does the magnetism of the magnetic roller weaken?

A: If it is properly maintained and placed, there will be no obvious weakening of magnetism within 10 years. Some users of magnetic cylinders need maintenance after a few years. The reason is not because the magnetic force of the magnetic roller is weakened, but because the pillow shoulder and the magnetic roller body are worn, or the roller is caused by improper pressure during use. Shaft bending.

Q: Does the magnetic force of the magnetic roller affect other parts on the die-cut seat?

A: The magnetic force of the magnetic roller extends only about 10 mm from the surface of the magnetic roller body, so it does not affect the other components on the die cutting seat. Of course, try not to make the magnetic roller body contact with other components, such as the bearing sleeve, the bottom roller, etc., in the device.

Q: Is the magnetic force of the magnetic roller smaller as the diameter of the roller is smaller?

A: In the case where the magnetic roller diameter is not less than the minimum recommended gear tooth number, the magnetic force does not become smaller as the roller diameter becomes smaller. However, it should be noted that the magnetic roller diameter must not be less than the manufacturer's recommended minimum size.

Q: Is there a limit to the minimum size of the magnetic roller?

A: The smallest and safest size recommended by magnetic roller manufacturers is: The circumference of the roller is not less than the width of the machine. However, if a smaller size must be used for various reasons, it is recommended that the 4:1 rule be followed: The diameter of the roller is not less than 1/4 of the width of the machine. Although the manufacturer can manufacture rollers smaller than 4:1, in order to smooth and even die cutting, to avoid buckling or even bending of the die, following the above rules will extend the service life of the magnetic roller as much as possible.

Q: Does high temperature affect the magnetic roller?

A: The permanent magnetic block of the normal die-cut magnetic roller can withstand temperatures up to 150 degrees Celsius. However, it is recommended not to place it under high temperature over 80 degrees Celsius for a long time, and to avoid uneven surface due to the expansion of the adhesive. It should be noted that the normal die-cut magnetic roller cannot be used for hot foil holders. Hot stamping magnetic rollers must withstand temperatures of at least 240 degrees Celsius.

Q: What is the difference between split type and tandem type magnetic rollers?

A: Split design refers to the pillow shoulder is disassembled, heat treatment to 60 to 62 Rockwell hardness has ensured the wear resistance of the pillow shoulder, the pillow shoulder can be removed and replaced after a few years, as far as possible to restore the original shape without wasting the original set of flexible blade. Joint design refers to the pillow shoulder and roller body as a whole material, the advantage is that the production cost is a little cheaper, the production time is relatively short, but the disadvantage is poor pillow hardness is not wear, resulting in a shorter life cycle of the entire roller. Rothley magnetic cylinders use a popular split design in Europe and Japan.

Q: Is the magnetic roller repairable?

A: Yes, but it must be tested by the manufacturer first. Depending on the conditions of wear and damage, the most common repair is to replace the pillow shoulder, repair the body, correct the shaft concentricity, and so on.

Q: Is it possible for users to use magnetic roller and flexible blade in different manufacturers?

A: Yes, but conditional. If the user's web has been equipped with magnetic rollers, but wishes to use a different manufacturer's flexible blade, the flexible blade manufacturer must know the diameter of the pillow of the original magnetic roller and the diameter of the roller body. Some magnetic roller suppliers in foreign countries often have the rules and error ranges that they have followed for many years. Even without their exact QC data, flexible blade manufacturers can infer the pillow diameter and barrel diameter, and then create a flexible blade to match if the user cannot measure it. But for those other magnetic roller manufacturers that have no rules to follow, in addition to providing QC data or measuring themselves, flexible blade manufacturers have speculated ways to design and manufacture flexible blades with precision requirements in the range of a few microns. And the possibility of mistakes is great. To ensure the close cooperation between the two, users generally use magnetic rollers and flexible blades from the same supplier.

Q: Does the flexible blade need to be positioned on the magnetic roller with a pin?

A: It is generally not recommended or need to use pin positioning. However, some special tasks, such as the use of magnetic cylinders with relatively small diameters by label manufacturers, are particularly complex in the shape of the die-cut and many lines, in addition to the magnetic roller itself should be installed super magnetic block, pin positioning can completely avoid the flexibility The possibility of sliding on the surface of the roller body of the magnetic roller due to die cutting resistance.

Q: How to install the flexible blade on the magnetic roller accurately?

A: Under normal circumstances, the operator can apply the flexible blade to the magnetic roller first beside the machine. The roller of the magnetic roller has a horizontal line for alignment, and the flexible blade also has horizontal and circumferential alignment lines, which has facilitated the alignment between the two. Then, the attached flexible blade and magnetic roller are put on the bearing sleeve, and the die-cut seat is mounted like a fixed round knife. Sometimes, for the convenience of the operator, the magnetic roller is first mounted on a die-cut seat, and then a flexible blade or a changeable position is attached to the machine. There is nothing wrong with this method of operation, but it needs to be done with special care so as not to rub the knife edge against the other parts of the die-cutting seat.

Q: Is it possible to save the cost of a flexible blade without using a magnetic roller?

A: Generally not recommended. If you try to use a common metal roller without a magnetic roller, whether it is stuck on the back of the flexible blade with double-sided tape, or sticking the edge of the flexible blade on the metal roller with tape, you can't make the flexible blade stick tightly. On the roller. The result is a flexible blade with a height error of only a few microns. Due to the gap between the back of the blade and the roller at the time of pad printing, the phenomenon of uneven die cut depth occurs. This is the case when more and more applications of automatic labeling are in use today. Unacceptable die-cutting quality.

Q: What is the difference between flexible grinding and back grinding?

A: The flexible blade was not accompanied by the application of the back grinding technique when it was just used. Later, manufacturers who started using back-grinding technology found that back-grinding can better control the overall height of the flexible blade, and regard back-grind as the highlight of its marketing. In fact, it was at that time that the CNC could not control the height of the blade at one time, but used a back-grinding tool to adjust it. Rothley flexible blades are introduced into Europe's most advanced CNC processing equipment, and once formed blades are not adjusted for back grinding in most cases. However, due to the uneven thickness of the die cut material, especially the backing paper, back grinding cannot be avoided in some cases. The back-grinded flexible blade is not much different in quality from a successfully-formed blade without back-grinding.

Q: What is the difference between a flexible blade used on an interstitial rotary machine and a flexible blade used on a full-rotor machine?