In the preparation of electrode materials for new energy batteries, the uniformity of 0.1mm strip-shaped particles directly affects the charging and discharging efficiency of the battery; In the production of 3D printed ceramic wire, fluctuations in the diameter of the extruded strip exceeding 5% can lead to printing failure. As the core equipment for continuous granulation, the rotational speed range of the rotary extrusion machine is not only a ruler of equipment performance, but also an "invisible conductor" that determines the microstructure and macroscopic properties of the material. From laboratory research and development to industrial production, precise control of rotational speed is becoming the key to solving the problem of high-precision material manufacturing.
1. Low speed zone (50-500rpm): Steady state extrusion, guarding fragile structures
In the preparation of biomedical carrier materials or highly active catalysts, excessive shear force can damage the pore structure of particles. At this point, the device achieves gentle molding through low-speed steady-state extrusion mode (50-500rpm). For example, in the preparation of mesoporous silica strip carriers, a research team set the rotational speed to 120rpm and combined it with the progressive compression design of a screw propeller to maintain the complete three-dimensional pore structure of the material during extrusion, with a stable specific surface area of over 800m2/g. This "low-speed high shape preservation" characteristic makes the rotary extrusion machine the primary choice for preparing sensitive materials.
2. Medium speed range (500-1500rpm): Balancing efficiency and accuracy
For most industrial grade materials such as ceramic filters and metal matrix composites, the medium speed range (500-1500rpm) is the golden balance between efficiency and accuracy. A certain new energy enterprise found through experiments that when the speed is increased to 800rpm, the extrusion efficiency of the positive electrode material of lithium-ion batteries is 40% higher than that of 500rpm, and the standard deviation of the diameter of the strip-shaped particles is controlled within± Within 0.02mm. More importantly, the medium speed range allows the equipment to match the rheological properties of different formula materials in real time through variable frequency regulation, avoiding blockage or breakage problems caused by viscosity fluctuations.
3. High speed zone (1500-3000rpm): Ultra fine granulation, breaking through size limits
In the field of nanomaterials and microelectronics, devices are challenging the lower limit of material size through high-speed extrusion (1500-3000rpm). A semiconductor company successfully prepared ceramic wires with a diameter of only 80 μ m using a high-speed mode of 3000rpm, meeting the precision machining requirements of 5G communication filters. The strong shear force generated by high-speed rotation can also induce mechanochemical effects in materials; — When preparing graphene composite materials, a rotation speed of 3000rpm increases the interlayer spacing of graphite by 30%, significantly improving the electrolyte infiltration performance.
From gentle care at 50rpm to cutting at 3000rpm, the speed range of the rotary extruder is essentially a "precision control valve" for material manufacturing. When the device can accurately control the speed in units of 1rpm, engineers gain comprehensive control over everything from microstructure to macroscopic performance; — This may be the underlying logic of modern materials science's transition towards high precision and high performance.
