The methods of forming particles in pellet granulators can indeed be divided into three categories: wet granulation, dry granulation, and hot melt granulation. The following is a detailed introduction to these three types of granulation methods:

1、 Wet granulation method of pellet granulator

1. Principle: Adding adhesive to drug powder, the bridging or bonding effect of the adhesive causes the powder to aggregate together and prepare particles. Wet granulation first involves the liquid in the adhesive wetting the surface of the drug powder particles, creating adhesion between the particles. Then, under the action of liquid bridging and external mechanical force, particles of a certain shape and size are formed, and finally solidified in the form of solid bridges after drying.

2. Methods: including extrusion granulation, rotary granulation, fluidized granulation, and stirring granulation.

3. Equipment:

Squeezing granulator: Use rollers, cylinders, etc. to force the material through a sieve, and adjust the sieve aperture to obtain the desired particles. The granulators designed based on extrusion granulation mainly include swing granulators, rotary extrusion granulators, and spiral extrusion granulators.

Rotating granulator: adding a certain amount of adhesive to drug powder, and under the action of rotation, shaking, stirring, etc., the powder is agglomerated into spherical particles.

Fluidized bed granulator: The powder is suspended by air flow, fluidized, and then sprayed with adhesive liquid to solidify the powder into granules. The process of boiling mixing, spray granulation, airflow drying can be completed in one equipment, and coating can also be done.

Efficient mixing granulator: a device that converts wet materials into granules through mixer mixing and high-speed granulation cutting. It is an advanced equipment that integrates mixing and granulation functions.

4. Characteristics: The particles made by wet method have the advantages of good quality, beautiful appearance, strong wear resistance, and good compression molding after surface wetting, and are widely used in the pharmaceutical industry.

2、 Particle Granulator Dry Granulation Method

1. Principle: The mixed powder of solid excipients and drugs is compressed into larger particles or flakes under high pressure, and then crushed into particles of appropriate size. This method does not add any liquid and relies on compressive force to generate binding forces between particles.

2. Methods: There are two types: rolling method and heavy pressure method.

3. Equipment: Dry granulation machines usually use feeding, pressing, hydraulic and other mechanisms to control the granulation process through variable frequency speed regulation and oil pump pressure regulation. The fineness of the finished product can be adjusted by replacing the sieve mesh.

4. Characteristics: The method is simple, labor-saving, and time-saving. It is commonly used for granulation of thermosensitive materials, drugs that are easily decomposed when in contact with water, and drugs that are easily compressed and shaped.

3、 Particle Granulator Hot Melt Granulation

1. Principle: Pellet preparation method using melting spray and ultra-low temperature freeze curing technology. After the material is uniformly mixed in the twin-screw hot melt extrusion section, it is transported to the atomization unit through a constant pressure and flow device. Under the action of a two fluid air flow nozzle or a centrifugal atomization disk, mist droplets are formed, and then enter the ultra-low temperature freezer for instantaneous heat exchange and solidification with ultra-low temperature air. The solidified particles enter the cyclone separator with the airflow to complete gas-solid separation.

2. Equipment: The hot-melt spray granulator is equipped with a PLC automatic control system, which supports the adjustment of 7 core parameters and has passed the GMP standard certification.

3. Features: The yield rate exceeds 85%, the particle size is adjustable from 20-200 mesh, and the material is almost 100% recovered. It is suitable for pharmaceutical, fine chemical, cosmetics and other industries, and can complete diversified processes such as solid dispersion preparation, particle coating, solution spray drying, etc.