Granulation affects how well your tablet press runs. Here’s what to focus on:
Before a tablet press even operates, a successful run begins with the material that is fed into it. Fine powders in tablet formulations are not ideal for tableting; they have poor compression, flow, and can stick to tablet press punches. Granulation is a process that helps increase fine powders’ flowability, bulk density, and as well as supporting their binding properties. Without it, tablets may have inconsistent weight or crack or crumble. Poor granulation can even seize up the tablet press during operation, risking damage to the machine.
Granule prep affects three important quality attributes in tablet production:
This guide aims to help tablet press operators to:
To avoid clogging, large holes in the mesh screen are needed for wet granules. A No. 4 or No. 6 mesh allows wet material to flow through the machine without stalling it. It also reduces the risk of forcing too much moisture into the granules, which can lead to material sticking to the tablet press.
Dry granules work well with finer mesh sizes. These screens can break up large clumps and loose agglomerates to help ensure that only uniform particles enter the tablet press, resulting in more consistent tablet weights and fewer die filling issues.
A bent or bulge in a worn screen can mean uneven granules. If the screen is stretched or damaged, powder particles may slip through in the wrong size, leading to inconsistent tablet weights and poor press performance.
Plate screens tend to be stronger and more resistant to deformation. They work best when granulating tough materials like dense or dry blends. If granules are wearing out standard plate screens too quickly, and using plates can extend production and prevent downtime.
One of the most important steps in preparing material for tablet compression is moisture control. Setting the moisture level correctly promotes consistent tablet quality, enhances flow, and helps avoid blockages whether you’re working with dry or wet granulation material.
Granule Type | What it Looks Like | Why It Matters |
Damp, holds shape, not sticky | Prevents screen clogging and machine stalls | |
Free-flowing, no dust clouds | Supports consistent tablet weight and flow |
A common mistake that directly affects the quality of granules and tablet press machine performance is feeding too much material into the granulator at one time.
Particularly for dry materials, the material needs to be fed slowly and in controlled amounts. Because dry granules don’t compress as easily, dumping too much at once will overwhelm the rotor. Allow the machine to work at its natural pace to maintain granule uniformity and prevent machine breakdowns.
Once the granulation step is complete, storage and handling of the granules has a direct impact on press performance and final tablet quality. Even well-formed granules can go to waste if they’re exposed to moisture, contamination, or physical damage before they reach the tablet press.
Avoid Moisture Pickup After Granulation
Use Proper Funnels and Containers to Transfer Granules
Prevent Dust Loss and Contamination
Taking the time to prep granules correctly before compression has a direct payoff: your tablet press runs better, your tablets are more consistent, and your equipment lasts longer.
Granules that are the right size, shape, and moisture content flow smoothly through the hopper and feed system. That means fewer jams, less bridging, and no need to stop and clear out clumped material mid-run. This is especially important for high-speed presses, where any hiccup can throw off production.
When every granule entering the die cavity is similar in density and size, you get even fill volumes. That leads to better control over tablet weight and hardness. It also prevents uneven stress on punches, which can extend tooling life and reduce the need for rework or scrap.
Poor granulation can cause excess dust, slugs, or hard agglomerates that damage parts over time. Well-prepared material protects the press’s moving components and reduces wear on feed frames, cams, and turrets. It also improves product quality, helping you meet specs after each production.
Getting granulation right is a critical part of tablet manufacturing that affects every stage after. When your material flows well, compresses cleanly, and meets quality specs, your press runs smoother and lasts longer. Whether you’re troubleshooting inconsistent weights or looking to boost output, proper granule prep is where to start. For teams using high speed rotary tablet presses, it’s one of the simplest ways to protect equipment and improve production at the same time.
If you need help improving your granulation process or want to make sure you’re using the right setup for your tablet press, Stokes is here to support you. Whether you’re looking for new granulators, replacement screens, or just have questions about how to get the most out of your equipment, contact the team at Stokes. We’ll help you find the right solution for your operation so you can keep production running smoothly.
If you’re doing wet granulation use a coarse mesh (No. 4-6). For dry material use a finer mesh (No. 10-16). A damaged screen can cause inconsistent granules.
Very. Too much moisture causes sticking and blocks; too little can cause poor flow and dust issues. Control moisture so material flows well into the tablet press.
Overfeeding can stall the rotor, cause uneven granule sizes and wear machine parts faster. It’s better to feed slowly and steadily.
Store granules in sealed containers in a dry environment. Use proper funnels or discharge systems to transfer them to avoid dust loss and contamination.
You’ll see smoother flow into the press, more consistent tablet weight and hardness, less punch wear, and fewer machine stoppages.
Yes. High-speed presses are less tolerant of flow issues. Uniform granule size, correct moisture and clean transfer all become increasingly critical.
