Structural Principles And Performance Advantages of Wet Granulation Machines

Wet granulation machines also called High-Shear Granulator or High-Shear Mixer Granulator are widely used in the pharmaceutical, chemical, and food industries as essential equipment for mixing powders and forming granules by combining powders with binders. As the pharmaceutical industry continues to push for more automated and standardized production processes, wet granulation machines have increasingly become mainstream equipment in the field of granulation due to their high efficiency, ease of operation, and compliance with GMP regulations. As one of the fast mixing granulator manufacturers and suppliers with more than 20 years of experience, Hywell Machinery has developed its high-performance Wet Granulation Machine—High Shear Granulator, engineered to meet stringent GMP requirements and optimized for both small-batch R&D and large-scale production. With its advanced control system, precise granule size regulation, and easy-to-clean design, our machine is widely used in pharmaceutical, nutraceutical, and food manufacturing environments.

This article systematically explains the structural composition, working principles, and key performance advantages of wet granulation machines, aiming to help users fully understand their critical role in modern production.

1.Application Background and Industry Demand

In the production of pharmaceuticals, food, and fine chemicals, raw materials often exist in powder form. Direct compression or capsule filling using these powders can lead to poor flowability and inadequate compressibility. Wet granulator addresses these issues by mixing powders with a binder to form granules, significantly improving compressibility, uniformity, and flow characteristics. It is a crucial step in the production of tablets and granules.

Compared to dry granulation, wet granulator is more suitable for applications that demand high-quality granules. It is widely used in the formulation of traditional Chinese medicines, antibiotics, nutritional supplements, and instant foods.

2.Detailed Structural Composition

The High-Shear Granulator features a compact structural design with excellent sealing and cleaning capabilities. It completes the entire process—from dry mixing and wet mixing to granulation—within a fully enclosed container. The main structural components include:

1. Main Frame

The machine adopts a rectangular frame comprising the base, gearbox, and bearing housing. The structure is stable and requires no special installation; it can be placed directly indoors. The feed hopper connects to the bearing housing and extends outward for easy operation.

2. Granulation Unit

Located below the hopper, the granulation drum is arranged horizontally and supported by front and rear bearings. It is driven via a rack-and-pinion system, enabling forward and reverse rotation. The front bearing seat features a detachable design—by removing just three screws, the drum can be easily disassembled for maintenance.

3. Sieve Clamping System

The system is installed on both sides of the granulation drum and consists of slotted steel tubes. The sieve is embedded into the grooves, and a handwheel tightens it around the drum's surface. The tension is adjustable to accommodate different particle size requirements.

4. Gearbox and Transmission

The machine uses a high-precision worm gear transmission with a 1:30 reduction ratio, offering excellent lubrication and low noise. An eccentric rod drives the rack in a reciprocating motion, ensuring stable forward and reverse rotation of the drum.

5. Motor Adjustment System

The motor is mounted on an adjustable plate connected to the base. A threaded rod alters the motor plate’s height, allowing for precise adjustment of the belt tension, which in turn controls the operating speed of the machine.

High Shear Granulator

Wet Granulation

High-Shear Mixer Granulator

3.Working Principle

The wet granulator process consists of two key stages: mixing and granulation.

1. Mixing Stage

Powdered raw materials enter the container and are stirred rapidly by mixing paddles. The inclined conical wall causes the powders to move and distribute uniformly. The binder is then added from a top-mounted hopper, forming liquid bridges that initiate agglomeration.

2. Granulation Stage

The powders are kneaded, compressed, and sheared between the paddles and the container wall to form soft, cohesive agglomerates. A cutter is then activated to chop these soft clumps into uniform, well-shaped granules. The material undergoes a transformation from “powder → agglomerate → granule.”

Unlike traditional compression granulation, this “cutting instead of pressing” method avoids problems with uneven particle sizes, resulting in rounder granules with better flowability.

4.Core Performance Advantages

The High-Shear Granulator delivers superior granulation performance while also excelling in automation, environmental protection, and safety. Key advantages include:

1. Intelligent Control System

Equipped with a programmable logic controller (PLC) and optional human-machine interface (HMI), the system enables standardized, batch-controlled production. Manual operation is also supported for R&D and parameter adjustment.

2. Precision Variable Speed Control

Both the mixing paddles and cutting blades feature frequency-controlled speed adjustment, allowing users to fine-tune the rotation speeds to control granule size and distribution.

3. Sealed and Dust-Proof Design

The rotating shaft chamber uses an air-sealed structure to prevent dust leakage and binder adhesion. An automatic cleaning function simplifies product changeover and enhances GMP compliance.

4. Optimized Temperature Control

The conical container design ensures uniform material tumbling. A double-layer jacket at the base, integrated with a water-cooling system, provides stable temperature control and improves granule quality.

5. Integrated Operating Platform

The lid opens and closes automatically, and the discharge port can be directly connected to drying equipment. Larger models include operator platforms or ladders for safe and convenient access

6. Easy Cleaning and Maintenance

A paddle-lifting mechanism allows thorough cleaning between the mixing paddles and the container, meeting stringent GMP cleaning validation standards.

5.Technical Comparison and Economic Benefits

Compared to traditional granulation techniques, the High-Shear Mixer Granulator significantly improves production efficiency:

Dry mixing takes only 2 minutes, and granulation 1–4 minutes, saving substantial time;

Binder usage can be reduced by approximately 25%, cutting production costs;

Granules are uniform with excellent flowability, enhancing appearance and tablet quality;

A shortened process flow reduces handling and contamination risks, aligning with GMP standards.

Statistics show that High-Shear Mixer Granulators increase production efficiency by 4–5 times compared to conventional equipment—especially valuable for large-scale pharmaceutical manufacturing.

6.Conclusion

With scientific design, flexible control systems, and high production efficiency, High-Shear Granulators have become essential equipment in modern solid dosage production lines. As the pharmaceutical industry demands greater precision, cleanliness, and efficiency in granulation, wet granulation technology continues to evolve toward intelligent and automated solutions.

Choosing a high-performance wet granulation machine compliant with GMP standards not only enhances product quality but also brings long-term economic value and competitive advantages to manufacturers.