What Are Industrial Shredders?

Industrial shredders are high-powered machines that cut through and destroy the toughest debris in all types of environments. They are primarily used in waste processing applications, often as the first step, to reduce the overall waste size and protect pumps and equipment from damage.

While all shredders serve the same purpose, they’re not all created equal.

In this blog post, we’ll explain the various types of industrial shredders and how they work.

Different Types of Shredders

The primary differences between shredder types are their overall design, how they cut materials, and how materials are fed into the hoppers.

Shafts

Single-Shaft

As the name suggests, this type of shredder has a single, solid shaft with rotary blades. In this design, material is typically fed through a hopper and pushed towards the rotating shaft by a hydraulic ram. The rotating shaft then shreds the material into smaller pieces that can pass through a screen with specific hole sizes, determining the final particle size.

Its primary advantage is that it can process a wide variety of materials, including plastics, wood, rubber, and textiles. You can find single-shaft shredders in plastic recycling, wood processing, rubber and tire shredding, and textile waste applications.

Dual-Shaft

A dual-shaft shredder works similarly to a single-shaft one, except it uses two counter-rotating shafts with blades that pull material through and shred it. They are particularly effective for heavy-duty shredding applications and are widely used in various industries to reduce the size of waste materials, including electronics, wood and biomass, metal, plastic, rubber, and other solid waste.

Quad-Shaft

Quad-shafts have four intermeshing shafts fitted with cutting blades. The blades on the shafts rotate to pull in and shear the material, creating a consistent shredding action. The four-shaft design makes it well-suited for heavy-duty shredding applications, especially for high-security documents or difficult materials that may otherwise jam or clog in single- or dual-shaft shredders.

Cutting Technique/Cutter Mechanism

Shear

Shear shredders use two or more counter-rotating shafts with cutting disks to create a “shearing” action that cuts the materials into strips or small pieces. The blades are positioned to overlap, ensuring the material is effectively grabbed and sheared as it passes through the rotating shafts. Single-, dual-, and quad-shaft shredders can be sub-types of shear shredders.

Shear shredders can handle large volumes of material quickly and process many types of materials. They’re commonly used to process plastic drums, pipes, and other bulky items and are ideal for any application requiring precise size reduction.

Pierce-and-Tear

Pierce-and-tear shredders use slowly rotating shafts fitted with sharp, hooked blades. The hooks catch materials and pull them through the tearing mechanism. This cutting method is particularly effective for reducing the size of resilient materials and bulky or irregularly shaped items.

Rotary Cutters

Rotary cutter shredders have a rotating shaft equipped with multiple cutting blades or knives. As the shaft rotates, the blades cut the material into smaller pieces. Shear and pierce-and-tear shredders are technically a type of rotary cutter.

Drum

This specialized shredder uses a rotating drum with cutting blades or hammers to shred materials instead of single or multiple rotating shafts. As the drum rotates, the attached blades or hammers cut, grind, and shred the material into smaller pieces. The material is typically fed into the shredder through a hopper or conveyor system, ensuring a consistent flow. A drum shredder can quickly process large volumes of materials, like organic waste and wood.

Grinders

Grinders use high-speed rotating shafts or drums equipped with cutting blades or hammers to grind materials into smaller pieces. They’re called grinders because they use a grinding and cutting action to reduce particle size. They often operate at high speeds, which results in rapid size reduction and a finer output. This type of shredder is commonly used for grinding plastic waste like bottles, containers, and film, in wood and rubber processing applications, and in organic waste management.

Chippers

Chippers feature a hopper or chute where materials are fed into the machine. Inside, a drum or flywheel with a set of sharp blades or hammers chips and shreds the materials into smaller pieces. They’re most commonly used to convert yard waste into useful mulch or compost, but there are also specialized plastic chippers used for processing high volumes of large items like crates or thick-walled containers.

Granulators

Granulators are used to create granules of materials and are particularly useful in recycling and reprocessing plastics, especially in injection molding applications. They feature a rotor with multiple rotating knives and a stationary bed knife. The material is fed into the granulator, where the rotating knives cut it against the stationary knife, producing small, uniform granules.

Hammer Mills

Although hammer mills can be classified as shredders, they don’t actually “shred” material. Their design features a rotor with swinging hammers attached to it. Any material fed into the machine is pulverized repeatedly by the hammers until it’s fine enough to pass through the perforated screen. They’re widely used to process metals, plastics, wood, and organic waste.

Material Feed

Hopper-Fed

Most industrial shredders can be classified as “hopper-fed.” This means that there is a hopper into which the material is fed into to be processed by the shredder. The hopper feed mechanism allows for easy and continuous feeding, making them suitable for high-volume applications. The hopper directs the materials into the shredding chamber, where rotating blades or knives cut them into smaller pieces.

Conveyor-Fed

Although hopper-fed is the most common type of industrial shredder, some shredders incorporate conveyor feeding. The conveyor belt system steadily transports materials directly into the shredding chamber. This design allows for continuous operation and reduces the need for manual feeding. Conveyor-fed shredders are commonly used in plastic recycling processes, as well as wood, metal, and textile waste processing applications. They’re also ideal for shredding mixed waste streams, bulky items, and construction debris.

Components of a Shredder

The standard components of most industrial shredders include:

• A rotor shaft (or drum)
• Cutters, which could be knives, blades, or hooks
• A feed hopper or conveyor system where the material is loaded into the shredder
• A drive system with a motor and gearbox

Learn More About Industrial Shredders

JWC Environmental is an industry-leading manufacturer of municipal and industrial waste processing equipment, including our renowned Monster® SHRED series, featuring five customizable hopper-fed shear shredder models.

Visit our blog for more industrial waste processing resources, or view our product portfolio to learn more about our industrial shredders.