The tablet drying granulator is a device that directly compresses powdered materials into granules without the need for liquid binders, and is suitable for materials that are sensitive to moisture or thermally unstable. Its working principle is mainly based on the following steps and mechanical actions:
1. Feeding system
Powder input: The raw material powder is uniformly fed into the pressure roller area through a spiral feeder or gravity.
Pre compression: Some equipment is equipped with pre compression devices to preliminarily eliminate air from the powder and improve the uniformity of subsequent compaction.
2. Compression molding (key step)
Roll squeezing: Powder is compressed into dense flakes or ribs under high pressure (usually 10-50 MPa) through a narrow slit between two counter rotating pressure rollers (usually made of stainless steel).
Roller surface: may have patterns or grooves to enhance the shear force on the material and promote particle formation.
Pressure regulation: Control the spacing and pressure of the pressure rollers through hydraulic or mechanical systems to adapt to the characteristics of different materials.
3. Crushing whole grains
Primary crushing: The pressed thin sheet is crushed into irregular blocks by a rotating scraper or coarse crushing device.
Whole particle screening: The block material is further crushed into particles of the desired size (usually 0.5-2 mm) through a rotating screen or a swinging granulator, and oversized particles are cyclically crushed.
4. Output and Collection
The finished particles are discharged through a vibrating screen or an air flow conveying system, and the dust is recovered by a dust collection device to increase the yield.
core principle
Mechanical compression: relies on high pressure to generate van der Waals forces, mechanical meshing, or local plastic deformation between powder particles, forming a stable structure.
Avoid liquid phase: No drying step required, suitable for thermosensitive or easily hydrolyzed drugs (such as certain antibiotics, probiotics).