How to Make Granules in Double Roller Granulator with Dry Granulation?

How to Make Granules in Double Roller Granulator with Dry Granulation?

Dry granulation is a widely used technique in the pharmaceutical, chemical, and fertilizer industries to convert powdered materials into granules without the use of liquids or solvents. One of the most efficient and popular machines for dry granulation is the Double Roller Granulator (DRG). This versatile equipment is designed to transform powders into uniform granules through a two-step process that involves compression and size reduction. In this guide, we will walk you through the steps to make granules using a Double Roller Granulator with dry granulation.

skin for double roller granulator

skin for double roller granulator

Step 1: Selection of Raw Materials

Before starting the granulation process, it is essential to choose the appropriate raw materials. The choice of materials will directly impact the quality and characteristics of the final granules. Typically, the raw materials consist of a combination of active pharmaceutical ingredients (APIs), excipients, or chemical components for fertilizers. Ensuring the materials are in powder form is crucial for the dry granulation process.

Step 2: Pre-processing of Raw Materials

If the raw materials are not in a suitable powdered form, pre-processing steps such as milling or crushing may be required. Milling reduces the particle size and ensures a more uniform distribution, enhancing the granulation efficiency. However, it is essential to monitor the particle size distribution and avoid over-milling, as it can affect the flow and compaction properties of the powder.

Step 3: Adjusting the Double Roller Granulator Parameters

The next step involves setting up the Double Roller Granulator to achieve the desired granule characteristics. The key parameters to be adjusted are the roller gap, roll speed, and compaction pressure. The roller gap determines the thickness of the granules, while the roll speed affects the residence time of the materials in the machine. The compaction pressure influences the density and hardness of the granules. Proper adjustment of these parameters is crucial for obtaining granules of consistent quality and size.

Step 4: Feeding the Raw Materials into the Double Roller Granulator

Once the granulator is properly set up, the pre-processed powders are fed into the hopper of the Double Roller Granulator. The gravity feeding system allows a steady flow of materials into the compression zone between the two counter-rotating rollers. Click here to get more details.

Step 5: Compaction and Size Reduction

As the powders pass through the compression zone, the rollers apply high pressure to compact the materials. The mechanical force exerted by the rollers causes the powders to adhere together, forming large agglomerates. These agglomerates are then broken down into smaller granules by the action of the milling screen located beneath the rollers. The size of the milling screen determines the final granule size, and it can be easily replaced to achieve different granule sizes.

Step 6: Sieving and Final Product Collection

After the granulation process, the granules are separated from any remaining fine particles and oversize agglomerates by sieving. The sieve ensures the granules are of uniform size and free from any impurities. The final granules are then collected and stored in appropriate containers or packaging for further use.


Dry granulation using a Double Roller Granulator is a reliable and efficient method for converting powdered materials into uniform granules. By following the steps outlined in this guide, you can produce high-quality granules with the desired size and characteristics. Proper selection of raw materials, adjusting granulator parameters, and careful handling during the process are crucial to achieving successful dry granulation. Whether in pharmaceuticals, chemicals, or fertilizers, the Double Roller Granulator offers an excellent solution for granule production through dry granulation. If you are interested in it ,you can visit

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