Vacuum Transfer Techniques for Rotary Die Cutting — An Overview
The use of the vacuum transfer technique allows non-stop transfer of die cut parts onto another part or web while maintaining accurate relative positions. As the material is starting to be cut, a vacuum is applied to the part in order to hold it in place on the face of the anvil. The anvil’s rotation then moves the part away from the web in a controlled manner after the cutting process, while the scrap matrix is directed up and away from the die cut part.
Rotating on the Anvil
The Vacuum holds the die cut part as the anvil rotates 180 degrees from the cutting position at which time a vacuum manifold ceases the vacuum and, if necessary, releases the vacuum seal to the part being transferred. The part is then free to fall from the anvil to a moving web passing beneath the anvil. To achieve the best results, we always recommend using a moving web with either adhesive or static that will securely hold the freshly cut and transferred part to the new web in position.
In some cases, the direction the bottom of the anvil roll’s rotation doesn’t match the direction of the moving web, and in these instances, the cut part can be transferred to a second vacuum roll. At this point, the cut part rotates another 180 degrees before it’s released of that second roll’s rotation onto the web going in the opposite direction. Effectively, this double transfer allows for continuous motion regardless of direction, saving valuable up-time.
When Vacuum Transferring is Needed
Vacuum transferring is particularly useful when the final position of a cut part onto a final web is crucial. This must be achieved at the highest-speeds possible in order to maintain efficiency. The cut part size and location are controlled entirely by the die during the cutting operation, and the vacuum allows this part to be held precisely where it needs to be on the roll before transferring to the web at exactly the right moment. A key advantage of vacuum transferring is its ability to work equally effectively with both porous and solid webs.
Vacuum transferring eliminates conveyors in some cases, and stackers in other, allowing any part to be instantly transferred to a web in any direction. With this in mind, the possibilities and gained efficiencies are nearly endless. Contact us today to dive deeper into the world of vacuum transfers. You’ll be glad you did!