Mechanics behind an advanced rotary machine

If you need fast, accurate die cutting, you can’t do better than an advanced rotary machine. These cutters can handle complex cutting, placement, registration and finishing steps in a single machine. That makes for a wonderfully streamlined process, ideal for quick turnaround and large volume orders.

In this blog, we’ll cover the rotary die-cutting process from start to finish, as well as explain the mechanics that allow an advanced rotary to accomplish so much with a single machine. Finally, we’ll highlight why the rotary die-cutting process at Sur-Seal® produces exceptionally high-quality results.

The rotary die-cutting process

Everything begins with the web in rotary die cutting. The web is a continuous roll of parent material. The web is fed into the cylinders of the machine and allowed to unwind. This means the manufacturing process can continue uninterrupted for exceptionally long stretches.

The cylinders the web is fed into contain dies that spin in line with one another. These dies can stamp out, kiss cut, laminate, register and/or join parts without the need for any operator intervention or transfer between machines. Completed parts are spun out of the back end of the cutter, while any scrap material or slugs can be collected automatically for recycling.

Production speed on a rotary die cutter is measured in feet per minute. And while total time from start to finish varies based on the complexity of the part and materials being used, advanced rotary die cutting is all-around one of the fastest fabrication solutions on the market.

The mechanics behind an advanced rotary

At the core of any advanced rotary machine are the cylinders, paired cylinders to be precise, into which the web is fed. These cylinder pairs (commonly known as rotary stations) are typically made up of one die-cutting cylinder and one hardened anvil cylinder. The two cylinders then rotate in opposite directions from each other. That opposite rotation allows them to continually draw in the web and process new parts in a single, smooth motion.

Some designs only require a single pair of cylinders, but more complex designs will usually travel through multiple rotary stations to create all the desired features. Sometimes, instead of a die-cutting and anvil pair, a rotary station will instead have male and female tooling sets. Such sets are used to create different desired effects on either side of a component, such as different crease lines.

With older model rotary die cutters, it was sometimes a struggle to achieve appropriate tension and alignment across the entire system when precision tolerances are needed. However, the Sur-Seal company uses a rotary converting platform, where each rotary station is powered by electronically geared servo motors. These servo motors allow each station to rotate with incredible precision — even at varying speeds. Tension can be adjusted, and registration can be corrected independently at each rotary station, resulting in exceptionally tight tolerances.

The importance of tolerance in rotary die cutting

Tolerance refers to the mechanical fit of a part, given any deviations it may have from the specification upon which it was designed, essentially, how much variability can be permitted before the final components no longer fit together as intended.

We wanted to call out tolerance, because it is one of the most scrutinized factors in the evaluation of manufacturing quality. The tighter the tolerance, the higher the quality of the work. For a capable, three-station rotary die-cutting machine, operation between ten- and fifteen-thousandths of an inch tolerance is generally considered acceptable.

However, with our machines, we can do even better than that. We can produce components displaying a tolerance within five- to ten-thousandths of an inch. Depending on the material and application, a reduction in tolerance variability by thousandths of an inch can drastically improve the quality and performance of the component.

Sur-Seal delivers excellence with rotary die cutting

Whether you’re looking for precision results, need a prompt turnaround or simply want to use a fabricator you can feel completely confident in, we’re with you at Sur-Seal. If you have a project in mind, request a quote today! You can also head to our die-cutting services page to learn more about the various die-cutting services we offer.