The negative pressure dry granulation machine is an advanced granulation equipment, and its process principle is mainly based on dry pressing technology. It directly presses powder into particles through mechanical force without adding liquid binder. The following is a detailed analysis of its core process principles:
1. Raw material feeding and preloading
The raw materials are evenly fed into the pressure roller area through a spiral feeder, and during the process, the air in the powder is removed through a degassing step to ensure uniform material density. Some equipment adopts a horizontal feeding design, which can reduce the leakage of fine powder caused by gravity and improve the yield.
2. Roll forming and pressing
The pre pressed material enters between two counter rotating pressure rollers, and the pressure is adjusted by a hydraulic system to compress the powder into thin sheets under high pressure. The surface of the pressure roller is usually designed with holes or patterns to enhance the biting force and forming effect.
3. Crushing and Whole Grain
The pressed thin sheet is roughly crushed by a crusher and then cut into standard particles through an adjustable sieve. The sieve aperture determines the particle size, and unqualified fine powder can be returned to the system for reprocessing to ensure particle uniformity.
4. Optimization of Negative Pressure Environment
Negative pressure design reduces dust through a suction system, improves workshop environment, and may assist in material flow and degassing, further enhancing particle density.
5. Drying and packaging
Dry granulation does not require additional drying steps, but some processes accelerate water evaporation through negative pressure environment, and the final granules are packaged after cooling.
Technical advantages:
1. No liquid addition: suitable for thermosensitive materials (such as certain antibiotics), retaining the efficacy.
2. Energy saving and efficient: 40% more energy-efficient than traditional processes, reducing dust by 60%.
3. Process simplification: Eliminating the drying step of wet granulation and reducing production costs.
The negative pressure drying granulator achieves efficient and environmentally friendly pellet production through mechanical compression molding combined with negative pressure optimization, and is widely used in fields such as medicine and chemical engineering.