Running a shredder in 2026 is about managing risk as much as processing feedstock. Material streams are inconsistent. Electric vehicles are entering the scrap cycle. Unknown hazards arrive at the gate. Equipment is more connected, but also more complex. And when something goes wrong inside a shredder, the consequences are rarely minor.

For Attar Metals Inc., a full-service recycler based in Mississauga, Ontario, protecting the shredder meant shifting the focus upstream and addressing stress and risk.

The risks are not theoretical. Tony D'Alonzo, maintenance manager at Attar Metals, has spent four decades working around heavy equipment and shredder operations, watching how small problems escalate once material reaches the rotor. From his perspective, the most effective way to protect equipment and the people working around it is to reduce stress before material ever reaches the hammermill.

When the shredder becomes the bottleneck

Attar Metals processes a mix of ferrous and non-ferrous scrap from industrial suppliers, dealers, and public drop-off. Before 2023, Attar Metals was feeding raw material directly into its shredder line. The machine was handling the brunt of the work, and the wear reflected it.

"We noticed that the shredder was working too hard. Too many breakdowns... [there was] a lot of wear and tear on that machine," D'Alonzo says.

The result wasn't just maintenance hours. It was a strain across the system from engines to downstream conveyors. On top of wear, there was a safety concern.

"Oh, number one is explosions," D'Alonzo says when asked about the biggest risk on a shredder line.

High-speed rotors introduced friction and sparks. If the material contains residual fuels, pressurized components, or hidden hazards, the consequences can escalate quickly.

At that point, the issue was no longer throughput. It was protecting the shredder from what it was being asked to absorb. Something upstream had to change.

Rethinking the flow by adding pre-processing

Attar Metals decided to expand the line and protect existing assets. In April 2023, Attar added the Blue Devil, a low-speed pre-shredder from Zato, positioned ahead of the shredder to prepare material before processing.

"It was an expansion to help our other machine out," D'Alonzo says.

Zato's Blue Devil is designed around a twin-shaft, high-torque configuration that uses counter-rotating shafts and replaceable cutting blades to shear material rather than fracture it through impact. Instead of relying on speed, the machine applies controlled force, gradually opening and reducing incoming scrap before it reaches the hammermill.

While Attar deploys the Blue Devil as a pre-shredder ahead of its primary shredder, the platform can also operate as a standalone processing unit or for aluminum scrap or busheling applications.

For Attar Metals, that distinction proved critical. Rather than feeding large, irregular scrap directly into the shredder, the Blue Devil introduced a controlled first stage of size reduction. Operating at low rotational speed with high torque, it shears and opens incoming material gradually, reducing bulk density, exposing enclosed components, and breaking down oversized pieces into a homogenous feed for the high-speed rotor.

When contaminants, trapped gases, or dense unshreddables enter a shredder at full speed, the consequences can escalate quickly. By comparison, the Blue Devil's slow-speed pre-processing limits friction, reduces spark generation, and stabilizes material flow entering the primary shredder.

The result at Attar was measurable operational relief. The change altered how material entered the mill and how the shredder responded. Since installing the pre-shredder, D'Alonzo has seen a significant reduction in downtime.

"Our maintenance has come down, everything has come down," says D'Alonzo. "It's a lot easier on [the shredder] now. Everything has already been processed."

According to D'Alonzo, the benefits extended well beyond the shredder itself. Reduced impact loads translated into lower wear on hammers and liners, fewer conveyor jams downstream, and less strain on engines and support equipment.

Just as important was safety. By addressing oversized and potentially hazardous materials under controlled, low-speed conditions, the Blue Devil reduced the likelihood of high-energy events inside the shredder, reinforcing Attar's focus on protecting equipment and people in the yard.

Zato

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