The Difference Between Granulators and Shredders

Granulators are part of a set of actions and machinery including grinding, shredding, and chopping.

These actions that have the purpose of breaking down, or reducing, scrap materials.

Typically, these processes are performed with plastic processing, but it can also be used with in other materials.

Every manufacturing plant that processes a material will have scrap materials. This will result as extra materials from the product being made and faulty or imperfect items.

One of the key goals to collecting and using scrap materials is so that profit is not lost. However, many businesses are also now looking at environmental impacts of their plants and seeing how re-using materials by using granulators, grinders, and shredders can not only act as a source of profit, but act in favour of environmental – issues as well.

Granulators and shredders

Here we will look at two of the most popular processing machines: granulators and shredders.

Granulators

Granulator machines can generally be classified in two categories:

• Central granulators are large and powerful, and so are made to process large amounts of scrap from many sources. There is often more machinery attached to them such as pipes or feeding hoppers that can ‘feed’ the granulator with materials at an ongoing pace.
• Beside-the-press models are built for lower material capacities and can grind items such as edge-trim, film lines, and off-spec parts. These items are then commonly turned back into the recycling process.

Granulators often have high-rotor speeds, where they operate at 400-500 rpm. They mostly process materials by slicing and cutting them, while the rotors make continuous ‘bites’ of the material.

Granulators can potentially experience jamming and rotor damage if materials go into the machine too quickly. It is best to have an overseer to make sure that items are the correct size before further processing.

Shredders

Shredders are built for high-processing volumes. They usually work at lower speeds than granulators, but with high torque that can let them process through most materials.

Because they are built as a powerhouse, shredders can process most materials including metals, wood, paper, and plastics.

Shredders are built in two ways:

• Single shaft shredders cut scrap in a downwards motion. They are built with a large motor where they can operate in heavy-duty operation but can be maintained easily.
• Dual-shaft shredders have two shafts, where they cut against each other to shred scrap.