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Monster Stack™

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The Right Cutter at the Right Location

Monster Stack™

The debris in wastewater varies. There are hard, abrasive materials such as rock and sand that are pushed along at the bottom of the waste stream. Then there are materials that float in the waste stream, such as stringy wipes and food scraps. And above the wastewater, the air is often high in H2S, which creates a corrosive environment.

When grinders need to operate in these individual conditions, there are ideal cutter configurations to run efficiently. But the solution for one environment is often not the ideal solution for another environment. Choosing a single cutter type for a grinder addresses one operational challenge while ignoring the others. That leads to dissatisfaction with grinder performance and operational life when the grinder does not address all of the needs of the installation.

The Monster Stack is JWC’s solution to this problem – a customized cutter stack to address the specific challenges of your installation. No longer do you need to settle on a single cutter type. A Monster Stack will mix and match the right cutter at the right location to optimize grinder performance and unit longevity.

What is a Monster Stack?

Muffin Monster

A JWC Monster Stack is a customized cutter stack that matches the right cutters to the expected challenges in the operational environment. Those challenges might not be the same from the bottom to the top of the grinder. As JWC uses individual cutters for its grinders, it is possible to mix different cutter types in the stack, and those changes can happen anywhere along the stack.

Why individual cutters versus monolithic cutters?

The performance advantage with individual cutters isn’t affected by the ability to mix different cutters in a single stack. Individual cutters can be machined to very tight tolerances as the whole cutter surface is accessible for the machining processes necessary to achieve extremely flat cutter surfaces. These finishing techniques cannot be used on the cutter surfaces of a monolithic cutter stack; therefore, it is not possible to maintain as tight of a manufacturing tolerance as compared to individual cutters.

So why is it important for the cutter surfaces to be very flat? It has to do with a shearing action. The less distance there is between cutter surfaces, the better the shearing action. Think about how scissors perform. When the scissor pivot screw is tight such that the blades have minimal distance between them, the shearing action between the blades results in a clean cut. But when the pivot screw is loose, increasing the distance between the blades, the scissors can no longer effectively shear, resulting in poor cutting of material. Scissors need their blades to pass close to each other to shear effectively. But it is also important that the scissor blades don’t touch each other as interference could damage the blades.

The effectiveness of a grinder’s shearing capability follows the same principles. When the distance between the cutter surfaces is minimal, the best shearing action happens. As that distance increases, the shearing action is less efficient. To achieve minimal spacing, cutters need to be manufactured to consistent and precise dimensions to realize the required spacing without actually making contact. Individual cutters can be manufactured to tight tolerances that are not possible with a monolithic design. Monolithic designs inherently have greater space between the cutters to make sure they will not interfere with each other. Therefore, a cutter stack with individual cutters will have more effective shearing action as they are designed for closer spacing.

Why do you need a Monster Stack?

Your grinder often needs to address multiple challenges from the bottom to the top of the grinder. The Monster Stack can place the right cutter at the right location to address the specific challenges you expect to see in your waste stream.

7 tooth cutter

Does your waste stream have a high level of rocks, grit and other heavy debris that flow at the bottom of the waste stream? The Monster Stack solution is a 7-tooth cutter configuration to crush these tough solids. You may want to utilize an extra-thick cutter configuration to improve the grinding efficiency and increase the longevity of the cutters in this zone. Whatever configuration is selected, know that these extra-tough cutter arrangements make quick work of these hard, abrasive solids while minimizing cutter wear.

7 tooth cutter

Are the cutters at the top of your grinder exposed to a high level of H2S? Grinders often operate in acidic environments. And grinders are also often oversized such that a significant portion of the cutter stack is not submerged in the waste stream under typical operating conditions. That means those cutters are exposed to an acidic environment, which will corrode the cutters over time. When those corroded cutters happen to be submerged and grind material, the corroded areas are susceptible to accelerated wear when abraded by solids. The Monster Stack solution installs corrosion-resistant stainless steel cutters in the region from the expected water line to the top of the grinder. The stainless steel will not be as susceptible to corrosion as the typical alloy steel cutter. When they do happen to be submerged and need to grind solids, they will not abrade at an accelerated rate that typically happens when corroded cutters are exposed to an abrasive environment.

Monster Stack Icons - Abrasion-resistant, corrosion-resistant, longer life

But why would one not just select an all stainless steel stack when operating in an acidic environment? Stainless steel is a softer metal than alloy steel. The hardness of alloy steel is better for longevity when grinding. Unfortunately, alloy steel corrodes more readily than stainless steel, making alloy steel a less-than-ideal solution in a corrosive environment. But as long as the alloy steel cutters are underwater, it is the grinding of materials that will abrade the cutters over time, not corrosion. With a Monster Stack, you have the ideal cutters to address the specific challenges above and below the waterline – stainless steel for the exposed cutters in an acidic environment above the waterline and alloy steel for the cutters grinding solids in the waste stream.


Do you have unique challenges in your waste stream? The Monster Stack can install a cutter to address the specific challenges of the expected debris. JWC has the Wipes Ready® cutter for those installations that are fouled by disposable wipes. A Wipes Ready cutter stack cuts wipes in two directions. The result is smaller particles that cannot reweave downstream, preventing the formation of ragballs. Other cutter designs may cut only in one direction resulting in thin strips that reweave over time leading to the formation of damaging ragballs. JWC also has all-purpose cutters for the waste stream that has a little bit of everything. And if a very fine grind is desire, JWC has a cutter that can produce that, too.

Where should a Monster Stack be used?

A Monster Stack should be used whenever you face multiple challenges in your grinder installation environment, and different cutter types are the best solution to address each challenge. A Monster Stack is designed to place the right cutter at the right location in the cutter stack to address the primary challenge in that zone. JWC is ready to work with you to design a custom Monster Stack that addresses the specific needs of your application.

What products can have a Monster Stack?

Monster Stack Products

JWC offers the Monster stack on the following products.

Can a Monster Stack be installed in an existing JWC unit?

If you have an existing JWC grinder that you think a Monster Stack will improve its performance and longevity, we can upgrade your grinder with a Monster Renew unit with a customized Monster Stack for your installation. Contact JWC to find your perfect Monster Stack.

Unmatched Cutter Customization

With the Monster Stack, the potential solutions are unlimited. JWC customizes The Monster Stack for your application to give you the right cutters to address your specific grinding challenges in your waste stream. By using the right cutter at the right location in your cutter stack, you optimize your grinder’s performance and longevity.

Contact a Representative

Find out more today about how JWC can fulfill your grinding, screening, shredding or processing needs.