Q: What is a dry roller compactor granulator?
Put simply, it is a machine that turns loose dry powder into uniform granules — using pressure only, with no water added.
Powders (pharmaceutical, fertilizer, chemical powders, etc.) are light, dusty, hard to transport and awkward to use. This machine takes those powders and, under enormous mechanical pressure, squeezes them into thin sheets, then breaks and sieves the sheets into evenly sized granules.
Think of it like making a biscuit: dry flour is fed between two counter-rotating rollers, pressed into a hard sheet, then crushed into uniform small pieces.
The key word is dry — no water, no liquid binder, no drying step. That is why it is called the "dry" method.
Q: How does it actually work?
The whole process is an automated production line, usually in four steps:
Feeding – Dry powder (moisture usually ≤5%) enters from the top. It is de-aerated and pre-compressed by a screw feeder so the feed is even and free of air.
Compaction – Two rollers rotate in opposite directions at the same speed, pulling the powder into the gap. Under high pressure (applied by a hydraulic system), the powder is squeezed into dense sheets or blocks. During rolling, the material density increases by 1.5–3 times.
Breaking – The sheets fall into a crusher/granulator where high-speed blades break them into coarse granules.
Sieving – A vibrating screen sorts the granules. The right-size granules go to the finished bin; oversized pieces are re-crushed, and undersized powder is recycled back to the feeder — a closed loop with almost no material loss.
Q: Which industries use it, and for what products?
It is used almost anywhere that turns dry powder into granules:
Industry
Typical Products
Pharmaceutical | TCM granules, antibiotic granules, capsule-fill granules, tablet ingredients |
Food | Instant drink powders, seasonings, flavors, sweeteners, nutritional supplement granules |
Fertilizer | NPK compound fertilizer, potash, formula fertilizer granules |
Chemical | Fine chemicals, catalysts, dyes, detergents, additives, resins |
Mineral / Metallurgy | Mineral powders, metal powders, coal, silica, soda ash |
New energy | Battery material powder granulation |
Q: What is the difference from wet granulation?
Dry method: no water → no drying step → lower energy, smaller footprint, shorter process.
Wet method: requires adding water or solvent to form a mass, then drying — more steps, higher energy, and unsuitable for materials that degrade with water or heat.
So materials that are moisture- or heat-sensitive (such as many pharmaceutical active ingredients) are the first choice for the dry method, and so are businesses seeking continuous, large-scale production.
Uniform, strong granules that do not easily break or absorb moisture;
Good flowability — granules do not cake, easy to store, transport and auto-pack;
Closed system with low dust, environmentally friendly and low material loss;
Low energy, small footprint, continuous production, high automation;
No liquid binders — friendly to heat-, moisture- and solvent-sensitive materials.
Q: What granule sizes are possible?
Granule size is controlled by changing the screen mesh and adjusting roller gap/pressure — typically around 0.3–5 mm, adjustable to your needs.
Q: What is the output capacity?
From small lab machines (a few kg per hour) to large industrial units (several tons per hour), depending on the model and material.
Q: What are the material requirements?
The material must be a compactable dry powder with moisture generally ≤5% — the powder particles need to "bond" under pressure. Materials that are too oily, sticky or non-compactable are not suitable.
