What are the advantages and disadvantages of the three common extrusion granulators?
July 13, 2020
Granulation refers to the operation of processing materials in the state of powder, melt, aqueous solution, etc. into granules with a certain shape and size. At present, the granulation processes used by pharmaceutical companies include extrusion granulation and shear granulation.
Among them, the extrusion granulation method refers to the method of mixing the drug powder and the auxiliary materials in the prescription uniformly, adding the adhesive to make the soft material, and then granulating the soft material through a sieve with a certain size by forced extrusion.
The industry said that in the process of extrusion granulation, making soft materials (kneading) is a key step. The wet and dry degree of the soft material should be suitable. Many productions are based on experience. It can clump together without clinging to the hand, and can be cracked by light pressure with fingers. The amount of wetting agent or adhesive depends on the nature of the material.
At present, the extrusion granulators on the market include screw extrusion type, rotary extrusion type, swing extrusion type and other granulation equipment. The characteristics are different and the functions are different.
Spiral extrusion granulator
Among them, the characteristic of the screw extrusion granulator is that the extrusion screw can be cooled or heated; the extruded barrel adopts a split structure, and the bolt can be removed to easily open the barrel and easy to clean. In addition, the screw extruder granulator can be equipped with a cutting knife to adjust the relevant speed to obtain short granules of the required length. At present, the screw extrusion granulator is mainly suitable for products that need to be granulated in industries such as rubber additives, food additives, plastic additives, catalysts, pesticides, dyes, pigments, daily chemical and pharmaceutical industries.
Rotary extrusion granulator
Rotary extruding granulator is to mix the soft materials evenly, under the squeezing of the rolling knife, the material is forced to pass through the screen, and is cut by the scraper to obtain the cylindrical particles of uniform length. It is characterized by low extrusion temperature rise, small extrusion aperture and large extrusion output, and is especially suitable for the granulation of viscous materials. However, there are also user reactions. In the granulation of sticky traditional Chinese medicine soft materials, the rotary extrusion granulator generates more heat during the extrusion process. The soft materials are too dry. In addition, the centrifugal granulation is easy to bond and requires Control the speed, time and air intake of centrifugal granulation.
Swing extrusion granulator
The swing extrusion granulator is specially designed for pharmaceutical, food, health care and other industries. The machine granulates at room temperature, and the powder is added to the hopper during work to directly make granules, forming at one time, which not only saves costs but also improves the quality of materials. The granules produced are smooth and bright, with moderate hardness, which is convenient for tablet production, packaging and storage, and capsule production.
Introduced in the industry, the swing extrusion granulator has low energy consumption, low noise, high output, easy operation and convenient maintenance; the drum is easy to disassemble and easy to clean. The screen is easy to replace; the mechanical transmission system is completely enclosed in the machine body, and the operation is safe; the place in contact with the material is made of stainless steel, which has advantages such as durability and is widely used at present. However, the swing extrusion granulator is not suitable for solid, liquid, slurry or grinding.