We Compare Shredders and Grinders. See the Differences

Intro

We’re frequently asked about the differences between shredders and grinders, so we’re going back to the basics to answer the question and help you decide which machine is right for your needs.

At their core, shredders and grinders reduce the size of waste materials. Both are common in wood and green waste, municipal solid waste (MSW), and construction and demolition (C&D) processing operations to reduce the volume of waste material and separate it so that it can be recycled into new, useful products.

Many people use the words “shredder” and “grinder” interchangeably, but they’re different in design and function, and it’s important to know what sort of applications each excels in so you can make the best purchase decision and optimize your facility’s processing throughput and overall profitability.

What’s the difference between a shredder and a grinder?

Both shredders and grinders take an input material and reduce its size. But that’s where the two machines’ similarity ends. Shredders take a waste stream of disparate materials and break large items down to smaller sized pieces; as small as 3 or 4 inches, and grinders reduce the size of a relatively homogenous input to as small as a quarter of an inch.

Many waste processing operations use shredders and grinders together, with the shredder performing the primary size reduction and the grinder doing secondary finishing work.

That’s the basic difference between a shredder and a grinder. Now, let’s cover some additional aspects that separate the two machines.

What is an industrial shredder?

Shredders are designed to take a waste stream that contains a variety of materials and break them down into much smaller sizes to be separated and further processed. Shredders feature a powerful rotating shaft or drum that is fitted with teeth to break down waste materials like carpet, mattresses, tires, pallets, branches, and construction debris, and much more. The drums operate at a low speed and with high torque to shred material, which is why shredders are commonly called “high-torque shredders” or “low-speed shredders.”

Shredders are typically loaded from the top, with front-end loaders or excavators dropping waste into a hopper to be shredded.

Applications for shredders

High-torque, low-speed shredders are great for processing waste materials and can handle C&D debris, wood and green waste, MSW, materials from land clearing operations, and storm debris. Shredders are often used as primary processors because they can better handle contaminants and remove ferrous metals with crossband magnets. They’re less likely to be damaged by metal, wires, and plastic contaminants and allow recycling operations to process a wider range of materials and create new revenue streams by transforming their waste into usable end products.

Shredders are ideal for:

• Contaminated waste streams
• Performing primary grinding operations
• Sizing material for sorting or density separation
• Separating metals from organic waste
• Reducing waste to a smaller size for more efficient transportation
• Recycling in urban areas because they are quiet and fuel-efficient

What is a grinder?

Grinders take a feedstock and cut, chip, and grind away at it to make small pieces from larger ones. They use a conveyor belt to feed materials to an enclosed grinding chamber where fast-spinning hammer mills pulverize the material, and do not discharge the contents until the grinding is complete.

Grinders are commonly called high-speed grinders or horizontal grinders and deliver a consistent grind, which allows them to excel at waste wood and green waste processing, biofuel source material production, and mulch and compost processing.

Applications for grinders

High-speed grinders are engineered for speed and throughput and generally process materials faster than high-torque shredders. They efficiently handle long materials like tree branches and limbs and are amazing tools to transform organic and green waste into valuable products like compost, mulch, and biofuel.

Grinders are perfect for:

• Grinding branches, logs, stumps, and brush from land-clearing operations
• Grinding reclaimed wood in C&D processing
• Converting organic waste into animal bedding, mulch, and compost

High-speed grinders create a final product with consistent sizing, and with a wide variety of cutters and screen sizes available, provide owners precise control over the final product’s size. This is ideal for creation of consumer products, which much be sized within specific ranges, such as:

• Mulch, typically sized between 1.5” and 2.5”
• Compost, which must be under 4”
• Biofuel, with varying size requirements, depending on power plant specifications

Why and when to use both a shredder and a grinder?

High-torque shredders and high-speed grinders offer different advantages for different recycling and processing applications, and it’s not strictly an “either or” decision because both can work together to help you achieve your operational goals.

Shredders can easily process contaminated or co-mingled waste streams to break down the initial materials into smaller, more easily processed sizes. Then a high-speed grinder can further process pre-shredded material into a quality end product.

Using both a shredder and grinder is particularly beneficial for facilities that receive waste from the general public or have a high contamination rate. By shredding first, contaminants can be eliminated before using high-speed grinders for final processing, enhancing operational speed and efficiency. Additionally, utilizing a shredder can prolong the lifespan of a grinder by eliminating contaminants that lead to excessive wear and tear on the grinder’s components, thus reducing downtime due to part failure caused by contamination.

So, there you have it; a down and dirty explanation of the differences between shredders and grinders. Maybe your operation needs one or the other, or maybe you could benefit from both working in tandem. If you still have questions, the environmental processing experts at Ecoverse can help you decide which is best for your operation or application needs. We can arrange a discovery call to learn about your needs and then set up a demo so you can see how a shredder or grinder can help your operation. We’re here to help!

Ecoverse provides the best environmental and aggregate processing machinery to the North American market, including a complete lineup of machinery to help you transform waste into revenue. We’ve been selling the best engineered and made shredders and grinders for two decades, and we can help you do something amazing: create something from nothing by converting waste products into sellable goods. Plus, do it more efficiently or faster. Simply put, Ecoverse helps you do more things, and do them better so your operation can achieve unprecedented levels of production and profitability.

Want to learn how we can help your organization do more, better? Contact us!