Waste and Slug Removal During Converting

Posted on: February 23, 2022

Unlike making donuts, the “holes” cut in the converting process aren’t usually a bonus!

Waste, slugs, and chad can cause all kinds of problems during a run without scrap management built into your converting process.  Waste removal is a necessary by-product to manage and an important discussion to have in keeping your press operating smoothly.

Avoid Damaging Your Tooling

Without some type of scrap management incorporated into your die design, waste can collect in the cavities and between the die blades. As waste builds up, and layer after layer of material stacks on top of itself in the die, pressure from that compression builds up and is exerted on the inside of the die cavity.  The cavity can fill quickly and at that point the pressure has to go somewhere so it breaks out the blades. This can happen during a run but even during set up if waste stays in the die and keeps packing in. 

The smaller the cavities, the more likely it is that waste will collect inside them. Investing in a scrap removal feature for the die can help ensure the job runs seamlessly and avoids unnecessary costs in replacing tools.

Prevent Unplanned Downtime and Quality Issues

Breaking blades on the die can cause irreparable damage to the tool but can also cause damage to other parts in the machine.  Also, the loose chad can find its way into ink or coatings or the end product causing a multitude of issues and increasing production time. Wilson Manufacturing offers many solutions for waste removal, customized to meet your specific needs.

Automated Waste Removal: Methods & Die Styles

Air Eject Dies

With the use of compressed air, you can introduce the air into the die and eject the parts from the cavities. Customized options are available to maximize slug ejection by isolating the airflow to focus on specific cavities. We offer three types of configurations for air eject dies: rotary union adaptor, air probe, and manifold styles.

Connecting with a rotary union to the end of the journal will allow air to flow through the die and out through air jets drilled into the cavities.  As the number of air jets increases, it may be more difficult to keep the air pressure at the necessary level for proper ejection so the air probe style is an option. The air is connected to this stationary probe inserted through the journal.  The air flows out the probe through a standard slot or through customized slots as the die cavity rotates over it.  This allows the air to be more concentrated as well as direct the airflow for collection of the scrap. 

When you need a custom air solution for a more complex set up or when blades are too close together for traditional air ejection, the manifold style allows for a custom delivery of air through ports drilled into the ends of the tool. These ports can direct the air flow to specific areas keeping a higher concentration of air flow and the manifold can be custom fitted to time the air flow.

Spring Plunger Dies

Spring Plunger dies are a great alternative to traditional air ejection slug removal. They are a cost-effective way to keep waste from building up inside die cavities while providing clean, reliable slug ejection from your die. These dies are built with spring-loaded plungers inside each cavity that compress during die cutting and then release to eject the slug from the die.

Pin Eject Dies

Pin Eject dies provide a premium quality slug removal without the use of an air source. Instead of being spring-loaded though, there are pins inserted through the die to push against a hard rubber roller core inside the die.  As the die cuts against the anvil, the pins stay below the blade height.  Once past the anvil, the pin is forced back up through the cavity by the rubber and pushes the scrap out.  A major advantage of the pin-eject die is its ability to fit pins within very small cavities.  Wilson’s Pin Eject dies can accommodate cavities as small as .0625” (1.59mm).

Scrap Recovery Attachments

Wilson vacuum attachments are designed to catch and remove waste when ejecting slugs from the die. The unit mounts between the frames on the exit side of the die station and can be attached to a vacuum source for continuous use while die cutting. The unit includes a scraper blade to prevent waste from collecting on the anvil.  Simply mount the unit, attach a vacuum source, and you’re ready to run. 

Vacuum Insert Dies

A Vacuum Insert die uses a vacuum source to pull the die cut scrap through the cavity into the center of the die and then out through the journal.  Our vacuum dies are designed with removable inserts for easy use and cleaning. One key consideration for vacuum insert dies is to ensure that the journal diameter is large enough for the scrap to pass through. Waste can then be collected for disposal or recycling.

Automated Waste Removal Enhances Quality and Uptime

Investing in waste removal systems for your tooling can save you time, money, and headaches in the long run. A Wilson expert can help you determine which waste removal style is right for your project. Use our online tool and connect with your region’s representative to discuss your project, or request your quote today!

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