Choosing the correct plastic granulator is one of the most important decisions when building or upgrading a plastics processing or recycling operation. The right granulator improves throughput, reduces scrap volume, lowers labor costs, and helps maintain consistent material quality throughout the recycling process.

At Arlington Machinery, we buy and sell used plastic granulators for a wide range of applications, including plastics recycling, injection molding scrap reduction, extrusion trim processing, thermoforming scrap recovery, and post-industrial recycling systems.

Whether you are processing PET, HDPE, PVC, polypropylene, or engineering-grade plastics, understanding granulator sizing helps ensure you select the right equipment for your production requirements.

What Does a Plastic Granulator Do?

A plastic granulator reduces scrap plastic into smaller, reusable regrind material. Granulators are commonly used in:

• Plastics recycling plants
• Injection molding facilities
• Extrusion operations
• Blow molding plants
• Thermoforming operations
• Post-industrial recycling systems

Granulators use rotating knives and stationary bed knives to cut material into smaller pieces that pass through a screen. The final particle size depends on screen size, rotor design, knife configuration, and machine horsepower.

Factors That Determine Granulator Size

Selecting the proper granulator involves more than simply choosing the largest machine available. Several factors determine the ideal size and configuration.

Material Type

Different plastics require different cutting forces and machine configurations.

Examples include:

• PET bottles
• HDPE purge
• PVC pipe scrap
• Film scrap
• Thick-wall plastic parts
• Engineering resins

Rigid materials generally require more horsepower and heavier-duty rotors than lightweight film or soft plastics.

Throughput Requirements

Throughput is typically measured in pounds per hour.

Typical examples:

• Small beside-the-press granulators: 50–500 lbs/hr
• Medium central granulators: 500–3,000 lbs/hr
• Large heavy-duty granulators: 3,000+ lbs/hr

Operations processing large volumes of scrap should prioritize:

• larger rotor diameters
• wider cutting chambers
• higher horsepower
• automated feeding systems

Part Size and Feed Opening

The size of the scrap entering the machine significantly affects granulator selection.

Large purgings, thick-walled parts, and bulky scrap often require:

• larger throat openings
• stronger rotors
• hydraulic feed assistance
• heavy-duty knife configurations

Smaller injection molded runners and lightweight trim scrap can typically be processed with compact beside-the-press units.

Horsepower Requirements

Horsepower directly impacts cutting capacity and throughput.

Typical granulator ranges include:

Higher horsepower systems are often required for:

• thick purge
• reinforced plastics
• automotive scrap
• large-volume recycling systems

Common Types of Plastic Granulators

Beside-the-Press Granulators

Beside-the-press granulators are compact machines designed for immediate inline scrap recovery near molding machines.

These systems are commonly used for:

• runners
• sprues
• small molded parts
• lightweight trim

Central Granulators

Central granulators are larger systems designed to process scrap from multiple production lines.

These systems typically offer:

• higher throughput
• larger cutting chambers
• automated material handling integration
• centralized recycling capabilities

Heavy-Duty Granulators

Heavy-duty granulators are designed for demanding recycling applications involving:

• thick-walled plastic parts
• large purgings
• pipe scrap
• automotive plastics
• industrial recycling streams

These machines often include:

• reinforced rotors
• oversized bearings
• high-torque drive systems
• aggressive knife configurations

Popular Plastic Granulator Brands

Arlington Machinery regularly buys and sells granulators from leading manufacturers, including:

• Cumberland
• Rapid
• Nelmor
• Herbold
• Conair
• Vecoplan

Buying and Evaluating Used Granulators

Purchasing used plastic granulators can significantly reduce capital costs while still providing reliable production performance.

When evaluating used granulators, buyers should inspect the rotor condition, knife wear, screen condition, bearing condition, size of the motor, electrical controls, and the overall machine condition.

Properly maintained used granulators often provide excellent long-term value for plastics processors and recyclers.

Browse Used Plastic Granulators

Arlington Machinery offers a large inventory of used plastic granulators and size reduction equipment for plastics processing and recycling applications. Our inventory frequently includes central granulators, beside-the-press granulators, heavy-duty granulators, shredders, and complete recycling systems from leading manufacturers.