Powder Making Equipment Fundamentals Explained: The Roles and Applications of Extruders, Cooling Belt, Mills and Mixers

Powder making equipment, such as extruders, cooling belt, mills, mixers, play a vital role in their respective fields by converting raw materials into the desired powder or molded product through different principles. The following is a detailed description of the basic principles of these machines:

1. Extruder

Extruders are mainly used in the manufacture of various plastic products. The basic principle is that the plastic powder raw material is heated up to the softening point and is extruded through the die under the pressure of the extruder to form the desired shape of the plastic product. The extruder is mainly composed of extrusion system, transmission system and heating and cooling system. In the extrusion process, the plastic powder is fed into the hopper of the extruder, pushed forward and heated by the rotating screw, and the softened plastic is further plasticized under the action of friction and shear force of the screw and barrel, and finally extruded through the specific shape orifice of the die.

2. Cooling Belt

Cooling belt is mainly used to press powder or granular materials into tablets of drugs or other solid preparations. The basic principle is that the material is filled into the holes of the die by means of a punch, and then pressure is applied to press it into shape. A tablet press usually consists of an upper punch, a lower punch, and a die hole. During operation, the upper punch is lowered to fill the die hole with material, pressure is then applied to compress the material, and finally the upper punch is lifted and the tablets are discharged through the demolding device. Different types of cooling belts (e.g. single punch cooling belt, rotary cooling belt, etc.) have different structures and scope of application, but the basic principles are similar.

3. Mills

Grinding mills work on the principle of crushing and grinding materials into powder by mechanical force. This process usually includes two stages: extrusion crushing and friction grinding. In the crushing stage, the material is crushed by strong squeezing pressure between the grinding rollers; in the friction grinding stage, the crushed material is further ground into fine powder under the friction between the grinding rollers and the material. The design of the mill takes into account the feeding, crushing, grinding, screening and discharging of materials, etc. By adjusting the parameters such as the pitch of the grinding rollers and the rotating speed, the particle size distribution of the powder and the output can be controlled.

4. Mixer

Mixer is mainly used to mix two or more kinds of powder, liquid and other materials evenly. Take powder-liquid mixer as an example, its basic principle is to use a specially designed rotor rotating at high speed to produce a vacuum effect, the powder is continuously and uniformly introduced into the fast-flowing liquid. In the mixing chamber, the powder and liquid are instantly and evenly dispersed and mixed under the action of the shear chamber. The design of the mixer focuses on the mixing efficiency, mixing uniformity and material loss, etc. By optimizing the rotor structure, adjusting the rotational speed and mixing time and other parameters can achieve efficient and uniform mixing effect.

In summary, powder powdering equipment (extruder, cooling belt, mill, mixer) through their unique principles of raw materials into the desired powder or molded products. These equipments have a wide range of application prospects in many fields such as pharmaceutical, chemical, food and so on.