wet granulation guide

In this guide, you are going to learn about two critical aspects – wet granulation process and wet granulation machines.

For that reason, this article will have two distinct sections, where I will exhaustively discuss each of these aspects.

Frankly, you can only choose a suitable wet granulation machine after knowing how wet granulation process takes place.

Even before I proceed, I would like you to review these two images:

Wet granulation process

A summary of how wet granulation process takes place: Image source: Pharmacy Tips

 

Basically, the two images summarize what I am about to discuss here.

Let’s go straight to the main subject of this wet granulation guide:

Section 1: Wet Granulation Process

This section focuses on the following key points:

  1. Definition of wet granulation
  2. Types of Granulation Processes & Techniques
  3. Wet granulation process – An overview of different stages in wet granulation
  4. Advantages of wet granulation process
  5. Disadvantages of wet granulation process
  6. Key application of wet granulation in industries
  7. Factors affecting efficiency of wet granulation

At the end of this section, I am sure you should be able to choose a suitable wet granulation machine.

Now, let’s discuss each of these points:

Definition of Wet Granulation

Wet granulation is the process of binding different powder particles together using adhesives or liquid solution.

All these occur under the action of an impeller.

This results in particle enlargement as you can see in the image below:

Wet granulation techniques

Granulation process. Image source: Research Gate (Article by A. Kumar, G. Bellandi, I. Nopens & J. Vercruysse)

Basically, this process does not depend on any compressive forces to form granules.

It is quite different from the roller compactor granulation process.

As you will learn later in this section, granulation is a critical procedure in pharmaceutical and food processing industries.

Mostly, you have to granulate powders before subsequent processing in the capsule filling machines or tablet press machines.

With all these in mind, now let’s have a quick overview of the various types of granulation processes.

Types of Granulation Processes and Techniques

For a fact, there are quite a number of material granulation processes and techniques today.

Therefore, it could have been unfair to focus only on wet granulation without mentioning other processes.

Whenever you think of granulation process in the pharmaceutical or food processing industries, the main options to choose from include:

  • Wet granulation process
  • Dry granulation process

You will learn more about the differences between the two processes shortly.

Normally, choosing a particular process will depend on an in-depth understanding of:

  • Physiochemical properties
  • Excipients
  • Release properties
  • Specific flow

With this knowledge, you can comfortably go ahead to choose an appropriate granulation technology.

Some of the most popular granulation technologies include:

· Roller Compaction

It is an example of dry granulation process.

I have written an interesting and informative article on this: Roller Compactor for Dry Granulation.

An example of roll compactor machine

Roll compactor process

Please spare some time to learn how roller compactor can guarantee material processing success.

· Fluid Bed Granulation

This is a good example of wet granulation technique.

Again on this subject, I have written a comprehensive article: A Definitive Guide to Fluid Bed Granulation Process.

FBG Fluid Bed Dryer Granulator

Fluid bed granulation and dryer machine

 

It is an important guide if you want to become a professional in fluid bed granulation process.

· High Shear Granulation/High Shear Wet Granulation Process

It is another example of a wet granulation process. Remember, this is the main subject of this article.

So, you will learn more about it shortly; just keep reading.

Now, let me go straight to the main differences of wet granulation vs. dry granulation processes.

First, in the wet granulation process, you will add a granulating fluid that can be water or other solvents.

It is this granulation fluid that helps in bonding particles together.

On the other hand, in dry granulation you don’t need any form of liquid. The process mainly involves compacting powder particles without adding any form of fluid or solvent.

Therefore, the compacting force is responsible for boding particles together.

Second, dry granulation process is suitable for materials that are heat and moisture sensitive. Such materials/substances are sensitive to both organic solvent and water.

Due to these variations in the granulation techniques and processes, the design of these machines is also different.

In both cases, the complexity of wet granulation vs. dry granulation processes will depend on the characteristics of the material/powder.

Now, let’s come back to the scope of this article – wet granulation process.

So, how does this process take place?

Wet Granulation Process – An Overview of Different Stages in Wet Granulation

Broadly, the granulation process involves the following critical stages:

  • Preparing material for Granulation
  • Wetting the powder/Add granulation solution
  • Agglomeration process
  • Drying process

Now, let’s discuss each of these processes in details:

1. Preparing Material for Granulation

This is the first stage in wet or dry granulation process. There are quite a number of pharmaceutical machines you can use in material processing.

These can include hammer mills, vibro sifter, IBC bin blenders, ovens, milling machines, etc. In short, there are hundreds of pharmaceutical machines in the market you can use to prepare materials ready for agglomeration.

Dry Granulator

Preparing material ready for granulation

Remember, the complexity of a wet granulation technique depends on the specific ingredients and characteristics of the material.

Some of the key elements you must evaluate when choosing material for wet granulation include:

  • Compressibility
  • Moisture content
  • Particle size
  • Hardness
  • Porosity
  • Bulk density

Of course, this should also go hand-in-hand with choosing the right wet granulation machine. You will learn about these machines in section 2 of this guide.

With an appropriate powder, you can proceed to the charging process. That is, the process of adding powder into the granulation chamber ready for agglomeration.

The impeller and the chopper will then begin to rotate. To optimize the mixing process, the machine should have a counter flow setup.

This will allow for good mass movement and homogenous mixing of the material.

Once the mixture is ready, it is now time to proceed to the next stage:

2. Add Granulation Solution

Granulation solution will facilitate the agglomeration process. In most cases, you can choose from either organic solvents or aqueous granulation liquid.

This will depend on the type of material you intend to process in the granulation machine.

  • Aqueous solution as granulation liquid

Generally, this granulation solution is eco-friendly, affordable and non-flammable. On the other hand, it has longer drying time and may affect the stability of the final product.

A good example of an aqueous solution is water.

  • Organic solvents as granulation liquid

Organic solvents are suitable for moisture sensitive products. They are also volatile, a reason why they dry faster.

However, they are more expensive and may be harmful to the environment. It is for this reason that you must dispose organic solvents properly after granulation process.

Some examples of organic solvents include ethanol or isopropanol.

Therefore, you will add granulation binder fluid when the powder is under the influence an impeller. That is, the impeller will be rotating.

In most cases, the granulation machine will spray the granulation solution from the top. You can see this in the image below:

Praying granules

Spraying powder during granulation process

Depending on the design of the granulation machine, you can add powder as foam or spray. In most drugs manufacturing processes, adding the granulation binder fluid as foam guarantees consistency and predictable distribution of the solution.

Now, it is at this point that particles begin to bind together – initial stage of the actual agglomeration process.

At times, you can also refer this process as powder wetting in the wet granulation process.

Next, we have the:

3. Agglomeration Process or Nucleation

The impeller will continue to rotate as you add the granulation binder solution. At this point, small granules begin to form.

We refer to these small groups of particles as nuclei.

As you add more granulation solution, the granules will increase in size as they collide with other powder particles.

summary of fluid bed granulation process

Granulation process

This process will continue until you have suitable size of the granules. It is this consistent growth in size of small granules that we refer to as nucleation.

Still, this is not the final product. This is because the granules at this stage have a granulation liquid – they are basically “wet or moist”.

4. Drying Granules Process

You need efficient drying equipment that can remove all granulation liquid or binder solution. Here, you can choose any of the following possible drying options:

  • Pharmaceutical or Tray Drying Oven

Although pharmaceutical drying oven is a common drying technique, it is labor intensive. Besides, some ovens may produce granules with varying porosity, composition and density.

pharmaceutical hot air circulation oven

A pharmaceutical hot air oven

This is due to the non-uniform drying phenomenon.

  • Fluid bed dryer

Fluid bed dryer dries granules faster than pharmaceutical ovens. Moreover, they ensure uniform drying.

A fluid bed dryer

Fluid bed dryer

At times, this process may result in material loss via attrition.

In summary, wet granulation process involves 4 main stages – preparing material, wetting powder, nucleation and drying.

Next, let’s have a quick overview of the advantages and disadvantages of the wet granulation process.

Like any other manufacturing process, wet granulation technology has both advantages and disadvantages.

Therefore, with this knowledge, you can comfortably evaluate the situation at hand to choose an appropriate pharmaceutical machine.

Advantages of Wet Granulation Process

Some of the main advantages of wet granulation process include:

  • It improves the flow properties of materials

In this granulation technique, you can easily increase the granule size with the moisture content. As a result, it is easier to increase flowability of the final granule.

For example, you can adopt this granulation process to increase the flowability microcrystalline cellulose.

  • Improves material compression and densification characteristics

You can easily produce very dense granules by using a high shear mixer or granulator.

  • Obtaining homogenous mixture is easy

From the rotating impeller to adding granulation liquid, you can easily produce homogenous granules. This is because the action of high shear granulation machines makes it easier for even and better distribution of particles.

  • Reduces air pollution

Both aqueous solutions and organic solvents reduce dust, which could otherwise cause air pollution. Remember, these granulation solutions also eliminate any possible generation and accumulation of static charges.

In addition to these, the granulation process reduces cross contamination and allows for better powder handling without compromising on homogeneity.

The modern wet powder granulation process is more cost effective and efficient than the old techniques. This makes it a perfect choice for quite a number of material processing procedures in the pharmaceutical industry.

Disadvantages of Wet Granulation Process

Below are some of the main disadvantages of wet granulation process you should know:

  • Possible loss of material

This is due to the numerous procedures and stages during the granulation process.

  • A complex process that can be tedious

Wet granulation processes involve many procedures. This makes it a complex process that can be cumbersome to control.

  • Initial installation can be expensive

Installation requires a lot of space (depending on the machine), time and the equipment itself can be costly.

  • It is difficult to stabilize the granulation process

For moisture sensitive materials, stability can be a major concern. This is because it will compromise the overall quality of the granules.

Basically, these are the main advantages and disadvantages of wet granulation process.

Now before we summarize this section, let’s list some of the main applications of this granulation technique.

Key Applications of Wet Granulation Process in Industries

Wet granulation is a popular process manufacturers use to produce a range of homogenous product mixtures. Some of the most common industries include

  • Pharmaceutical or drug manufacturing industries
  • Chemical processing industries
  • Food and beverage processing industries
  • Fertilizer manufacturing industries, just to mention a few

In each industry, the manufacturers use granulation process to mix various ingredients, excipients, chemical components, etc. to ensure consistent, reliable and homogeneous products.

Here are some practical examples:

   · Wet Granulation for Tablet Manufacturing Process

From choosing binding solution to the granulation process, you can produce different types of tablets. By adopting wet granulation process, you can produce tablets with better:

  • Flow characteristics
  • Bioavailability
  • Homogeneity
  • Compressibility
  • Stable ingredients, etc.
Wet granulation for making tablets

Tablets

Clearly, you can see why we use granulation in tablet manufacturing process in pharmaceutical or drug manufacturing industries.

   · Wet Granulation in Fertilizer Manufacturing Process

Wet and dry granulation techniques are popular processes of manufacturing fertilizers. Fertilizer manufacturers use wet granulating machines to homogenously mix various minerals and chemical constituents.

Furthermore, they use the high shear granulation machines to produce dense granules with the right chemical composition and size.

Wet granulation for manufacturing fertilizers

Fertilizer granules

In short, you can produce superior fertilizer products by choosing a suitable wet granulating machine.

   · Producing Concentrates & Foodstuff using Wet Granulation Process

Wet granulation is a popular method of producing a range of food concentrates, sweets, chocolates, etc. in the food and processing industry.

You can use this granulation technique to process/manufacture food products such as milk powder, instant coffee, chocolate mix, cubes, etc.

Wet granulation for manufacturing food products

Milk Powder – Image source: NDTV

To sum up the applications of wet granulation process, it is quite clear that this technique plays a pivotal in various manufacturing processes.

That is where the end product should be granules or requires further processing like in the case of tablet compression process.

Now, let’s move to the last item of this section before we focus on granulating machines in section 2.

 Factors Affecting Efficiency of Wet Granulation

There are quite a number of factors that affect quality of the wet granulation process. Here are some of the key factors you must consider:

   · Quality of Wet Granulation Machine

There are many wet granulation machines that produce granules with different densities and sizes. Therefore, it is important to choose high quality and reliable machine whose performance is predictable.

For a fact, granulation machine plays a critical role in this process. It is for this reason that I have a whole section that will focus on granulation machines.

I will explore these machines shortly, keep reading.

   · Compatibility between Material and Binding Solution

Can you remember what I said earlier in this section about wet granulation process? Let me remind you:

Well, you can choose either organic solvents or water depending on the type of material. This will depend on the physical and chemical properties of the material or its excipients.

These may include:

  • Hydrophobicity
  • Solubility in granulation liquid
  • Surface area
  • Particle size
  • Compressibility, etc.

Take for example, whenever you are processing materials that exhibit good compressibility, it is advisable to go for a weak binder solution.

On the other hand, for porous materials, you will use more granulation liquid. This is also the same case whenever you are granulating hydrophilic material.

Clearly, to improve on the efficiency of any wet granulation process, you must know the properties of binding solution and material.

   · Granulation Time

Longer wetting period will result in hard granules.

In most cases, these are the main factors that affect the quality of the wet granulation process. Others may include temperature and viscosity of the granulation solution.

Now, this marks the end of our discussion on wet granulation process.

Next, we are going to explore an important section in granulation process and this is the wet granulation machine.

Section 2: Wet Granulation Machines

In this section, you will learn about 8 important aspects of wet granulation machines. These will include:

  • What is a granulator machine?
  • Why do you need a high shear granulator?
  • Parts and components of high shear granulation machines
  • The working principle of high shear wet granulation machine
  • Types & classification of high shear mixers
  • Technical specification of high shear wet granulation machine
  • Quality compliance of high shear mixer granulator
  • Where can you buy a high shear wet granulation machine?

I believe with this information, you can choose granulation machine that will meet your unique granulation requirements.

Here is an example of a rapid mixer granulator:

Now, let’s explore the above 8 points in details:

What is a Granulator Machine?

Granulation machines are electromechanical devices that bind particles together, thereby causing particle enlargement. It is the machine we use in the granulation process (refer to section 1).

These machines come in different shapes, designs and capabilities depending on the production needs.

You can classify granulator machines as either low shear or high shear machines.

Basically, this classification depends on the magnitude of the force that a machine exerts on materials for homogenous mixing and subsequent granulation.

Therefore, low shear machines use very little mechanical force to mix and bind powder particles. A good example is the fluid bed granulators.

Fluid bed granulation

Fluid bed granulation – particles suspended by air

Fluid bed granulators use air to suspend powder particles while spraying binder solution at the same time. This action causes powder particles to collide and bind together forming granules.

Ideally, this process requires less mechanical force. It is for this reason that they produce less dense granules.

On the other hand, high shear granulators exert more mechanical force on powder particles while adding granulation liquid. As a result, they produce very dense granules due to their high speed.

For the scope of this wet granulation guide, the main focus will be on high shear granulators.

Still, in case you want to learn more about low shear granulation, here is an in-depth article on that subject: A Definitive Guide to Fluid Bed Granulation.

So for the remaining part of this article, the main focus will be on high shear wet granulation machines.

Why Do You Need a High Shear Granulator?

Obviously, in any wet granulation process, our end product will be granules with varying:

  • Porosity
  • Granule shape
  • Density
  • Size

Therefore, for the purpose of this section, I will focus on unique features why you should go for high shear granulators.

But first, even before that, let’s review the table below that compares fluid bed and high shear granulation processes. It will give insights on when you should opt for high shear granulation process.

Wet granulation vs. fluid bed granulation

A study by Garett Morin and Lauren Briens

This comparison was done by Garrett Morin and Lauren Briens on their publication about high shear granulation processes vs. fluidized bed granulation process. You can bookmark that link to know more about their study.

For now, let’s go straight to the scope of this section:

First, high shear granulation process is suitable for a dust free agglomeration of powder either as final products or for further processing. The good thing about the granulation technique is that the entire process takes place in a closed container with blending tools.

Second, in case you need denser granules with compact structure, then high shear granulation is a perfect choice. As I had indicated earlier, the high mechanical force and speed produces dense granules.

Additionally, granules from high shear granulation have better flow characteristics. Therefore, they are suitable for other manufacturing processes such as tablet compression.

Third, you can adapt the high shear granulation process for both continuous and batch granule production processes.

In short, the choice of a specific type of wet granulation machine will greatly influence various characteristics of the final granules.  Thus, choosing a high shear granulation or fluid bed granulation machine will depend on your unique production needs.

Next, I want to discuss various parts and components of high shear mixer granulator.

Parts and Components of High Shear Granulation Machines

From the first image in this section 2, it is quite evident that high shear granulation machine is an assembly of different parts and components.

So, let’s try to disassemble this granulation machine before we review how it works. Through this, you will learn a lot about high shear mixer granulators.

For a fact, high shear granulation machine has hundreds of parts and components. The number of parts may vary with the design and functionalities.

Some of the main parts of high shear wet granulation machine include:

Parts and components of high shear granulation machine

Summary of different parts of high shear granulation machine

Closed Container/Granulation Drum/Mixing Drum

This is a stainless steel container with all the material blending tools and accessories such as the mixing blades, chopper, impeller, granulation fluid spraying nozzle, etc.

Parts of high shear granulation machine

An internal section of granulation drum

The design is such that it isolates the mixing chamber from the external environment. Therefore, the high shear wet granulation machine guarantees a dust free environment.

Depending on the capacity and design, the mixing drums come in a wide range of shapes and sizes. However, the conical shapes are the most common.

The slanting sides allow material to mix freely. Furthermore, they do not have sharp corners or edges that can hide powder or granules.

Quite a number of granulation drums have a circular base. This allows for free movement of material.

Again, these mixing drums should have an O-ring seal at each of its openings.

Main Impeller of the Granulation Machine

The main work of the impeller is to mix materials and spread the granulation liquid. Depending on the impeller design, its rotational speed may range from 100rpm to 1,500 rpm.

The impeller can rotate either horizontally or vertically, depending on the orientation of the high shear granulation machine.

Impeller of a high shear granulation machine

In most cases, you will find machines with an impeller that has three tangentially positioned wing-tips. This increases the efficiency of the entire process.

Still, there is always a concept you must understand while examining the blades of a high shear granulation machine’s impeller.

A wet granulation machine with only three impellers will require high rotational speed. This is the only way it can produce granules with the right density and size.

The main challenge with high rotation speed and mechanical force is the undesirable thermal stress and high granule breakage.

It is for this reason that you will find high shear granulation machines that have elongated side wings. This way it can rotate at a reasonable speed and still achieve a good mechanical force for granulation.

High Shear Granulator Chopper

You can also refer to the chopper as a secondary impeller. In most cases, it rotates at a relatively higher speed that may range from 1,000 to 3,000 rpm.

The speed of rotation will depend on that of the impeller.

Position of an impeller and chopper in a high shear granulation machine – Image source: Lauren Briens and Ryan Logan publication

Quite a number of choppers feature “U-shaped” blades and they break down wet lumps thereby producing granules.

The position of the chopper may vary depending on the wet granulation machine design. However, most machines have chopper mounted on the wall of the granulation bowl/container.

In addition to these, a research by Lauren Briens and Ryan Logan, fixes impeller speed at 700 rpm and that of the chopper at 1,000 rpm to guarantee optimal granulation.

Please ensure you discuss this with your high shear granulator manufacturer. This is the only way to know when the machine can achieve optimal wet granulation.

Sealing Mechanism

As part of the cGMP design requirements, high shear wet granulation machines have Teflon seals. This is common on both the chopper and impeller shafts.

Sealing mechanism for wet granulating machine

Different types of Teflon sealing

This prevents any possible leakages during the wet granulation process.  

Motor Drive Mechanism

Basically, for the chopper and impeller to rotate, your machine must have a drive mechanism. High shear granulators have motor drive systems that regulate and control the granulation process.

Quite a number of machines have the variable frequency drive system (VFD). This allows users to precisely adjust various speeds of both the impeller and chopper for optimal granulation.

Safety System for High Shear Granulators

Safety is an essential aspect for any electromechanical equipment.

First, wet granulators feature various safety interlock systems. For example:

  • You cannot access the drive mechanism when the machine is ON.
  • Machine cannot start when the mixing area is open.

In short, before you purchase any machine, ensure it has all the important safety measures.

Granules Discharge

The final granules will leave the granulation bowl/drum/container through the discharge port. It can be for further processing or packaging.

Different parts and components of high shear granulation machine

Sections of granulation machine

Depending on the design of a high shear granulation machine you can discharge granules directly into a receiving container or sizing milling.

Normally, the milling machine further breaks down granules into even sizes. This will also depend on your unique specifications.

High Shear Granulation Machine Frame

It will depend on the structure and design of the machine. In most cases, these high shear granulators have a stainless steel frame.

Granulation machine

Frame that hosts the entire structure of the granulation machine

It is the frame that hosts the drive assembly, granulation bowl, electrical control systems, etc. The frame should be strong to accommodate all weights besides the vibrations during the wet granulation process.

Spraying Nozzle for Binding Solution/Granulation Liquid

This is a critical aspect in any wet granulation process. You should have a system that optimally delivers granulation liquid.

Parts and components of high shear granulation machine

Inner component of high shear granulation machine

The nozzle of your high shear wet granulation machine should atomize and deliver suitable droplets of binder solution. Besides, it should distribute the binder solution evenly on the material.

To achieve this, you must take into account the following while considering the best spraying nozzle:

  • Granulation solution pump

You can choose either a peristaltic or mechanical pump. Alternatively, you may also opt for special pumps depending on the type of material you are granulating.

A peristaltic pump for high shear granulation machine

A peristaltic pump

  • Granulation solution pressure pot

In case you need an efficient and excellent dispersion of binder solution, you can opt for pressure pot. It ensures fast and high pressure delivery of the granulation solution.

Again, the position of the spraying nozzle may vary depending on the design of the high shear granulation machine. However, it is mostly above the material you want to granulate.

Electrical Control Panel for the High Shear Granulation Machine

The complexity and design of the control system will also depend on the design, configuration and control software in the wet granulation machine. This can be in the form of a touchscreen HMI.

Parts of high shear granulation machine

Electrical control panel panel for a high shear granulation machine

Depending on its unique design, it can:

  • Allow for changing various process parameters
  • Display system parameters such chopper speed, impeller speed, system temperature, various warnings, etc.

It has various indicator lamps, while coordinating and controlling various operations of the machines. At the moment, quite a number high shear granulator manufacturers use the PLC control systems.

As a matter of fact, it is common to find manufacturers varying the design and components of high shear granulation machines. The aim here is to develop an efficient and reliable machine.

Again, it is important to remember that, these are just a few parts and components of high shear granulation machines. This machine is an assembly of hundreds of small parts/components.

To know every section of the machine, please download or request for an installation manual from your granulation machine manufacturer.

For now, let’s move to another important section of this wet granulation guide:

The Working Principle of High Shear Wet Granulation Machine

First, I want you to watch this video on how a high shear granulation machine works:

In section 1, I did mention some critical aspects about the wet granulation process. In this section, I will explore how we can achieve every stage in that process.

Let’s go right to the working principle of high shear granulation machine.

Step 1: Fill the Granulation Container/Bowl with Material

Depending on the design of the high shear wet granulation machine, it will automatically fill the container with the material.

So, by pressing buttons or functions, material will automatically flow into the container. This process is automated such that, once it reaches a certain level, it will automatically stop.

Working principle of high shear granulation machine

Adding material to the granulation chamber

As the material fills the system, it will displace the air that was initially resent in the granulation bowl.

Again, I should also mention that there are machines where you have to fill the material manually. That is, open the lid of the granulation container, pour material then close.

Step 2: Starting the Mixing Process

Once the material reaches a specific level, it will automatically stop the charging process. The vacuum valve will then close and the exhaust valve opens.

Thereafter, the chopper and the impeller will begin to rotate. You will use the control panel to set the speed of rotation for both the chopper and the impeller.

Working principle of high shear granulation machine - mixing chamber

Mixing material in the granulation chamber

When you look at the above video, you will realize that the direction of rotation of the chopper is opposite to that of the impeller. This basically ensures optimal and homogenous mixing of material.

The action of both the chopper and impeller causes a tangential and whirling tumbling motion. It basically results in the fluidization of every particle, hence an even mixing.

As you can see from the video, material moves from the center to the edge of the granulation container. Material does not stick on the stainless steel granulation container.

You should allow this process to continue until you achieve a homogenous mixture. Then, the machine will automatically proceed to step three.

Step 3: Add Granulation Solution

Here, the spraying nozzle will turn ON automatically. It will then direct the binding solution on particles that are in constant random motion.

All these take place at the same time:

  • Spraying granulation liquid/binding solution
  • Chopper and impeller rotating at preset speed
  • Material is under mechanical shear force, hence move randomly within the granulation drum
How high shear granulation machine works - adding granulation fluid

Adding granulation solution

It is the compressed air and the pump that forces the granulation liquid or binding liquid through the spraying nozzle.

At this stage, the various particles will then begin to agglomerate into granules.

The granulation liquid will wet every granule further forming large lumps. It is the chopper that reduces these lumps into reasonable sizes of the granules.

Once you get the right density and size of the granules, it is now time to discharge the product.

Step 4: Discharge the Granules

At this stage, the spraying nozzle will automatically turn OFF then the speed of the impeller reduces. The discharge door will then open.

How high shear granulation machine works - discharging granules

Discharging granules from the granulation chamber

As the impeller rotates at low speed, it will push the granules to the milling chamber. Here, the milling component will uniformly reduce the wet granules to a reasonable size.

From this point, you can transfer the wet granules to the drying chamber for further processing.

As you can see, the working principle of high shear wet granulation machine is quite simple. It will also remain the same, irrespective of the design.

In most cases, high shear wet granulation machine manufacturers introduce technologies that optimize every stage in the granulation process.

With that in mind, let’s now classify the existing high shear granulation machines.

Types & Classification of High Shear Mixers

First, let me acknowledge that we have many models of high shear mixers/granulation machines. The choice of a particular machine will depend on your unique agglomeration needs.

Types of high shear wet granulation machines

Types of high shear wet granulation machine

Second, classifying wet granulation machines will also depend numerous features, some of which may be beyond the scope of this guide.

For this guide, I will focus on two critical classification criteria. These will include:

  • Position of the granulation tooling system (impeller and chopper)
  • Production capacity

Let’s have a quick overview of these two important points:

Types of High Shear Granulation Machines (Focus: Tooling System)

Here, we classify different types of high shear mixers depending on the orientation and location of the tooling system. As a result, we have:

  • Vertical high shear granulator machines

In vertical shear granulator machines, the design of the impeller is such that it rotates in a vertical plane. Depending on the design, these high shear mixers can either be bottom or top driven units.

  • Horizontal high shear granulator machines

For the case of horizontal high shear granulator machines, the design of the impeller is such that the rotation is in a horizontal plane.

Another important mode of classification is:

Types of High Shear Mixer Machines with the Focus being Production

First, there are high shear granulation machines whose design allow for either batch or continuous production.

Batch operated high shear mixers are machines what allow for one or more production stages. That is, to get the final granules, material must pass through a set of processing procedures.

That is, before you begin producing the second set of granules, you must complete the current granulation process.

Continuous operated high shear mixers are those that the granulation process is carried out as a single task. That is, there are no breaks during the granulation process.

Such systems feature sophisticated automation and control mechanism.

Apart from these two, production capacity also plays a critical role here.

For example, we have high shear wet granulation machines specifically for:

All these will determine the specific application of the machine.

Even with all I have shared in this guide, there is critical information you must before buying any high shear wet granulation machine.

This is the technical specification of the machine.

Technical Specification of High Shear Wet Granulation Machine

Although the information on the machine’s name plate form part of the technical specification, it is not enough. This is why I insist that you must review the manual or technical data of a high shear wet granulation machine.

This is what I am talking about:

Technical aspecification of high shear wet granulation machine

Technical information for SaintyCo Oscillating Granulator OSG Series

It is through this that you will know whether the machine is suitable for your wet granulation process of not.

Apart from the technical specification, other critical information you know is the quality compliance of the machine. I will explore this in the next section.

Quality Compliance of High Shear Mixer Granulator

Let me make this clear:

A high shear mixer granulator is an assembly of mechanical, pneumatic, electric and electronic systems. Therefore, at any stage, they must comfort to the safety and quality standards in the market.

Furthermore, you can also use high shear mixer in many industries such as pharmaceutical, food processing, fertilizer, agrochemicals, etc. In each case, the high shear granulation must conform to the set regulations and rules.

Basically, what I am saying is that, you need to understand the quality requirements in your industry before purchasing the machine.

Therefore, the machine must be:

These are just a few quality regulation requirements. At times, the quality requirements may vary from one geographical location to another.

More importantly, you need to buy a high shear wet granulation machine from a reputable manufacturer. They are the only companies that give quality a priority.

For this reason, let me take you through a simple process on where you can buy a wet granulation machine.

Where can you Buy a High Shear Wet Granulation Machine?

I find buying a high shear granulating machine from the original manufacturer to be convenient and a good idea. It is even better if you source it from the high shear granulating machine manufacturers in China.

One thing that I can assure you is that, even the European or American companies have OEM partnerships with the Chinese high shear granulator machine manufacturers.

Thus, by dealing with these companies directly, you will save a reasonable amount of money.

The truth is that Chinese high shear granulating machine manufacturers:

  • Offer competitive price on unit sets of granulation machines
  • Blend European, American and Chinese technologies or innovations hence guarantee optimal wet granulation process.

At SaintyCo, we offer a range of high shear wet granulation machine for both R&D and large scale production. We are known for our turnkey solutions in the pharmaceutical equipment besides our exemplary technical support team.

Conclusion

At this point, I know you have learnt quite a lot about wet granulation process and wet granulation machine. With this knowledge, you can easily optimize all material processing operations to achieve a high ROI.

Furthermore, with this information, you can choose suitable wet granulation machines for the specific needs of your pharmaceutical or food processing industry.

Now it’s your turn:

Do you have any questions or inquiries about high shear wet granulation machines?

Feel free to contact us for free consultation.

References

  1. The Effect of the Chopper on Granules from Wet High-Shear Granulation – By Briens, L., & Logan , R.
  2. Pharmaceutical Granulation Processes, Mechanism and the Use of Binders – By Cantor, S. L., Augsburger, L. L., & Hoag, S. W.
  3. Wet Granulation Process – By Thoudhary
  4. Tablets Manufacturing Methods and Granulation Techniques – By I.S
  5. High Shear Granulator – By Ozioko, C
  6. Granulation Techniques and Technologies: Recent Progresses – By Shanmugam, S
  7. Wet Granulation Process for Tablet Manufacturing – By Tipa, P
  8. Pharmaceutical Blending and Mixing – Edited by Cullen P. J. et al
  9. Handbook of Pharmaceutical Granulation Technology – By Parikh, D. M
  10. The Granulation Process – By Tousey, M. D
  11. Granulation – By Rahul S