Why consider rotary punching?
This is basically a question about volume, existing machinery and technology used to convert the product to be punched. One of the considerations for rotary punching is, that with a basic speed of 500 ft/min approx. 200,000 ft of material can be converted per 8 hr. shift. Due to the ease of integration into existing machinery and processes sometimes even low production volumes are justifiable.

How does rotary punching function?
In general, the larger the tool diameter, the better it is for the punching process because of a more relaxed entry angle of the punch into the die. When using soft and oversized punches and a hardened die they will shear in during the first revolution and caliber themselves. When using hardened matched metal punch and dies the punch and die bore dimensions are in relation to each other. The closer the tolerances are kept, the better and longer the punching process will work to your satisfaction. The tight tolerance timing between the punch and die tools is essential and a guarantee for best performance which is usually achieved with hardened and ground gears in anti-backlash design.

What kind of materials can be rotary punched?
Most non-ferrous materials and plastics such as Paper, Tag Stock, Board, Pulp, PP, PE, Polyester, Nonwoven, Foils and Laminates made of these materials. In general, one could say, the heavier and harder a material is the better, while the thinner and more flexible materials are less suited for rotary punching. This is also true for fibrous materials such as nonwovens. It's always best to provide some sample material with your inquiry.

What hole sizes can be rotary punched?
During our more than 50 years of experience we have punched holes in a variety of sizes from 0.030" ø to windows in envelopes. In this day and age, depending on the material, die cutting should be used for dimensions larger than 1" ø. For hole sizes smaller than 0.030 our hot or cold needling techniques are most suitable.

What is the maximum speed?
Our tools and equipment perform at speeds of up to 2,300 ft/min. Please keep in mind that this depends very much on the material and the hole size. With a diameter of 0.040", for example, a maximum speed of approx. 250 ft/min can be expected.

Can my service technicians service the tooling?
Generally speaking yes. We always try to design the tools so that the punches and dies are individually exchangeable. Depending on the hole pattern this is not always possible. In those cases our service technicians can help. We discuss with our customer the best tool design in regards of service and best performance. Sometimes it is necessary to make a decision in favor of one or the other.

What is the difference between a soft punch system and a hardened matched metal punch system?
A soft punch system consists of a hardened die and a soft punch. The soft punch shears in and calibers itself the first time it penetrates into the die. Due to the fact that the punch is soft or semi hardened, the lifetime expectancy is not that good.

The hardened matched metal punching system consists of a hardened die and punch. This allows to manufacture the die ID and the punch OD in a certain tolerance to each other. This allows to replicate the lifetime cycles within narrow margins.

What are the advantages of the hardened matched metal punch system over the soft punch system?
Since the punches and dies are manufactured in tolerance to each other there are no metal shavings that have to be removed after the first penetration, which could contaminate the web or the production process. If not properly removed, it is also possible that these shavings get lodged between the punch and the die and thereby wear the punch beyond normal wear. Many different punch and die materials can be selected, even Tungsten Carbide (TC). With TC naturally the lifetime expectancy dramatically increases and can be up to 100 times better than the soft punch system, especially when punching abrasive materials. An additional advantage is that the holes are cut clean longer and less hanging chad or dust is created. This can be very important for additional down stream operations. Critical materials such as films can also be processed successfully.

Why should I consider buying punching equipment from Schober?
Our name stands for excellent Execution, top Service, and outstanding Productivity. As a solution provider we first consult, then provide solutions, and sell last. We are known in the industry to provide tooling that can punch clean holes accurately into just about any web fed material, with long service cycles and best productivity. Our 150+ strong team is your support worldwide. Our 50+ years experience in rotary punching will be your know-how advantage.