The dry granulation method is commonly found in the pharmaceutical, chemical, and agriculture fields. Learning its operating principle and advantages can facilitate your project’s progress. Through the introduction in the following article, we hope it will be greatly helpful to your granulation production!
What is Dry Granulation?
The dry granulation method can transform powdered materials into granules through compression and crushing, but not using liquid solvents.
It is suitable for heat-sensitive or moisture-sensitive materials, which can improve granule flowability, facilitate your later processing, and at the same time save energy and reduce your production costs.
The Working Principle of the Dry Granulation Method
Mixing Raw Materials
Firstly, mix the raw material powders evenly. If necessary, add flow improvers or lubricants to guarantee the powders’ uniformity and the later pressing’s smooth progress.
Compression Molding
Using a roller granulation machine or tablet press, then apply high pressure to the mixed powder to make the powder particles tightly adhere to each other and form a tablet strip or block. This process is achieved not using the liquid adhesives.
Break into Particles
Break the pressed materials into the desired particle size you need. Uniform particle size can improve fluidity and tablet-making performance, easier for you to carry out later processing.
Screening and Grading
Screening removes particles that are too large or too small, and adjusts the particle size grades. Finally, you can obtain stable and suitable particle products for tablet pressing or packaging.
Dry Granulation Method Advantages
No Water Required
The dry granulation method does not use water or organic solvents, nor does it require heating or drying. Therefore, it suits materials sensitive to temperature or humidity. It can protect the active ingredients and prevent degradation or deterioration.
Reduce Energy Consumption and Production Costs
Because the dry granulation eliminates the humidification and drying steps, it
will reduce energy consumption, while also reducing the drying equipment investment and production time, thus lowering your total production costs.
More Efficient
The dry granulation process mainly consists pressing and granulation. It has fewer steps and is easy to operate, thus resulting in a shorter production cycle. It suits enterprises requiring rapid production or continuous production.
Improve Particle’s Compressibility
Mechanically compressed particles have a denser and more uniform structure, significantly influencing the powder’s flowability and packing properties, which is beneficial for your later tableting, filling, or packaging.
More Environmentally Friendly and Safer
Without using solvents, it will emit no volatile organic compounds (VOCs). At the same time, it also reduces the flammability and explosiveness risks, enhancing the production environment’s safety. This enables your production to better comply with environmental protection regulations.
Reduce Material Loss and Pollution
The dry granulation method is relatively enclosed, with less dust leakage, it can reduce your material loss and also reduce the cross-contamination risks. The dry granulation method is particularly suited to the medicine and food industries with high standards.
Dry Granulation vs Wet Granulation
Process Principles Comparison
Dry granulation requires mechanical pressure to compress your powder into tablets or strips, and then break them to granules. No liquid is used in this process.
In contrast, wet granulation adds binders or solvents to make the powder be wet mass, then dried and sized. The steps are more numerous and complex.
Energy Costs Comparison
Dry granulation does not require drying, so it can reduce your energy consumption and equipment investment. However, wet granulation requires additional drying equipment (such as fluid bed dryers), and its operating costs are higher.
Materials and Applicability Comparison
The dry granulation particles have higher density and better fluidity. However, in some cases, the particles may not be as uniform as those obtained through wet drying. Since dry granulation suits heat-sensitive and moisture-prone materials, it is commonly used in the pharmaceutical and chemical industries.
The wet granulation particles are usually stronger and have a more regular shape. It suits materials that require increased viscosity. Therefore, wet granulation is often used in traditional pharmaceutical production and in the high viscosity products manufacturing.
Environmental Safety Comparison
Dry granulation does not use solvents, which is more environmentally friendly and safer, it suits industries with strict environmental requirements.
In the wet granulation process, solvents will evaporate, and accordingly, there will occur recycling and safety management problems.
Common Dry Granulation Applications
Pharmaceutical Industry
Dry granulation is widely used in the pharmaceutical industry, especially for heat-sensitive materials or active pharmaceutical ingredients (APIs) sensitive to moisture. It can improve the powder’s flowability and compressibility but not affect the efficacy, easier for later tabletting or capsule filling.
Chemical Industry
In the chemical field, dry granulation can put fine powdered raw materials into uniform granules, reducing dust, enhancing materials fluidity, and improving storage and transportation stability. At the same time, it is conducive to achieving automated production.
Food Industry
Dry granulation is often used in the food additives, seasonings processing, etc. It can make your product particles more uniform, less prone to caking, improve solubility, and meanwhile prevent spoilage.
Health Supplement Industry
In the health supplement production, dry granulation can manufacture vitamins and plant extracts. This method can maintain the active ingredient’s stability, and improve your product’s tablet-making performance.
New Energy Industry
In the new energy field, you can use dry granulation to process battery materials or high-performance powders, helping to increase the particle packing density, thereby optimizing its later molding or processing performance.
Pesticide Industry
Dry granulation can transform powdered pesticides or fertilizers into granular products, reducing dust pollution, while improving storage and transportation performance, making your products more suited to mechanized applications.
FAQ
What is the Best Dry Granulation Pressure Range?
The dry granulation pressure needs to be adjusted by your material’s characteristics, generally covering tens to hundreds kN. You need to determine the best pressure parameters through experiments to make sure the formed granule’s strength.
Does Dry Granulation Have Requirements for the Powder’s Particle Size?
It generally requires the powder to have a uniform particle size distribution, as both overly coarse and overly fine particles can affect the compaction effect. When necessary, you need to carry out pretreatment and screening.
Is the Dry Granulation Equipment Maintenance Very Difficult?
The dry granulation equipment maintenance is relatively simple. You mainly need to inspect and clean the rollers, screens and transmission system, and perform regular maintenance.
How to Determine If Your Materials Suit Dry Granulation?
You can judge the materials’ compressibility, fluidity, as well as their sensitivity to water and temperature. We suggest you conduct a small-scale test to prevent the dry granulation method from not suiting your production.
What are the Differences with Dry Granulation and Spray Drying?
Dry granulation can press powder to granules, while spray drying turns liquid into powder. They suit different material forms and process requirements.
Final Thoughts
Dry granulation, with its simple principle and numerous advantages, leads the way in granulation solutions. If you have any other questions about dry granulation, please feel free to contact Pilotech at any time. Pilotech is committed to ensuring every partner can obtain the best granulation solution!
