What You Need To Know About Extrusion Spheronization - A Quick Guide

What Is the Purpose of an Extruder?

An extruder is designed to shape a wet powder or granule mix into continuous strands or rods called extrudates. Key functions include:

• Shape formation: Forcing material through a die creates cylindrical extrudates of precise diameter.
• Density control: Adjustable screw speed and die geometry allow control of compaction and porosity.
• Throughput management: Designs handle a few hundred grams to over a ton per hour.
• Feed customization: Modular dies and interchangeable screws accommodate different formulations and moisture levels.

By converting granulated mass into uniform rods, extruders are ready for downstream processes. Whether that’s cutting into pellets or rounding into spheres.

What Is the Purpose of a Spheronizer?

A spheronizer rounds short segments of extrudate into near-perfect spheres via friction and rolling action. Its main roles are:

• Shape refinement: A rotating friction plate tumbles extrudate fragments, smoothing rough edges.
• Size uniformity: Adjusting plate speed and run time yields tight particle size distributions.
• Surface finish: Friction polish produces low-surface-roughness spheres for consistent coating or packing.
• Batch flexibility: Configurable bowl size and discharge options let you process from a few liters to hundreds.

Spheronization improves flowability, packing density, and aesthetic appeal in end products.

Extruder vs. Pelletizer: What’s the Difference?

Aspect	Extruder	Pelletizer
Output form	Continuous rods or sheets	Discrete pellets (via chopping blades or dies)
Shape control	Die-driven diameter, high uniformity	Blade or die head determines pellet length and shape
Typical use	Pre-shaping for spheronization or drying	Final pellet production for feed, fertilizer or fuel
Equipment	Screw-barrel assemblies; variable-speed	Die plates or cutter wheels; rollers or discs
Density range	Medium to high (drag flow compaction)	Variable; often lower compaction than extrusion
Scale	Lab to large-scale continuous operation	Batch or continuous for moderate throughputs

Why Extrude and Spheronize?

• Improved flowability: Spherical particles roll and pack predictably, preventing blockages.
• Controlled size distribution: Tight particle ranges ensure consistent feed rates and performance.
• Enhanced coating: Smooth spheres pick up uniform coating layers for controlled-release or catalytic uses.
• Reduced dust: Rounded particles shed fewer fines, improving safety and cleanliness.

Process Steps at a Glance

1. Mixing/Granulation: Blend powders, binders and liquids into a cohesive wet mass using a kneader or granulator.
2. Extrusion: Force the wet mass through a die to form continuous extrudates with controlled diameter.
3. Sizing: Optionally cut extrudates with a knife or pelletizer into short segments for spheronization.
4. Spheronization: Load segments onto a rotating friction plate to round them into spheres.
5. Drying & Coating: Remove residual moisture and apply functional coatings if required.

Key Equipment Features

• Variable-speed drives for precise control of screw or plate RPM
• Modular dies & screens to tailor extrudate diameters (0.6 – 8 mm)
• cGMP-compliant construction for pharmaceutical and food applications
• Non-stick surfaces for easy cleaning and fast product changeovers
• Heating/cooling jackets to maintain optimal process temperatures
• Automated discharge valves for hands-free batch transfer

Lab-Scale vs. Production-Scale Tools

Bench-Top Development

Model	Function	Batch Size	Size Range
MG-55 Multi Granulator™	Mixer & Extruder	~0.2 kg	0.6 – 8 mm
QJ-230T Marumerizer®	Spheronizer	~1 L	0.5 – 10 mm
KDRJ-2 Batch Kneader™	Mixer	~1.2 L	N/A

Production-Scale Machinery

Model	Function	Throughput	Extrudate Size
EXDS-100G Xtruder™	Extruder	100 – 300 kg/hr	0.6 – 2.0 mm
EXDS-180 Xtruder™	Extruder	500 – 1,200 kg/hr	0.6 – 2.0 mm
QJ-700TG Marumerizer®	Spheronizer	20 L/batch	0.5 – 10 mm
QJ-700TWG Twin Bowl	Spheronizer	2 × 20 L/batch	0.5 – 10 mm
BR-450 Basket Granulator™	Extruder	150 – 750 kg/hr	0.6 – 2.0 mm

LCI Test Center Capabilities

• Full equipment lineup: Lab and pilot extruders & spheronizers handling gram to hundred kg batches.
• Modular tooling: Rapid screening of dies, plates and screws to tune particle shape and throughput
• Analytical labs: In-house particle size analysis, moisture measurement and torque monitoring
• Formulation expertise: Guidance on binder selection, feed rate and moisture targets
• Detailed reporting: Data-driven recommendations for seamless scale-up

Benefits of Pilot Testing

• Risk reduction: Uncover scale-up challenges (e.g., torque spikes, stickiness) before full production
• Parameter optimization: Fine-tune screw speed, plate RPM, moisture and binder levels for target quality
• Cost savings: Minimize waste and unplanned downtime by validating on pilot rigs
• Representative samples: Generate real-world spheres for customer evaluation, coating trials or performance testing

Getting Started for Entry-Level Users

1. Formulation Screening: Use the MG-55 and QJ-230T to test binders, moisture and speed settings on small batches.
2. Pilot Trials: Schedule Test Center runs on pilot EXDS and QJ machines; review LCI’s reports to finalize parameters.
3. Full Production: Scale to high-capacity EXDS-180 extruders and QJ-700TWG twin-bowl spheronizers with CIP and automation for consistent, large-batch output.

LCI’s equipment and Test Center expertise can help you confidently develop, optimize and scale a robust extrusion and spheronization process.