The operation of mixers relies primarily on material displacement, diffusion, and convection; specific structural designs enable the uniform blending of different materials within the hopper. The mixing process is achieved through the combined action of three physical mechanisms: convective mixing (where material rises along the hopper wall and slides down, causing macroscopic positional exchange), diffusive mixing (where random particle movement leads to microscopic dispersion), and shear mixing (where velocity differences between material layers break up agglomerates). An electric motor drives the main shaft directly via a pulley and gearbox, causing specially shaped rotating blades mounted on the shaft to spin. Under the influence of centrifugal force, the material rises along the conical walls of the stationary mixing vessel, creating a swirling motion; this facilitates the rapid and uniform blending of materials with varying densities.
The **plough-blade mixer** operates by replacing standard mixing blades with fixed plough-like blades while the mixing vessel itself rotates. Two sets of blades are used: one set turns the material outward, while the other turns it inward, ensuring the material is continuously separated and turned over to achieve a uniform blend. The **twin-shaft blade mixer** utilizes two S-shaped blades rotating at different speeds and in opposite directions to blend the molding material. The **edge-runner (muller) mixer** consists of a rotating pan and muller wheels; the motor drives the pan, and friction causes the wheels to rotate and crush the material, while scrapers and manual shoveling loosen the mix to ensure uniformity. The **dual-vessel mixer** features a stacked arrangement; the upper vessel sifts the resin liquid and abrasive grains through an outlet into the lower vessel, where resin powder is added and a rotating scraper ensures thorough mixing. The **ball mill mixer** employs a sealed rotating cylinder containing numerous ceramic or steel balls; as the cylinder rotates, the raw materials and balls impact and grind against the cylinder walls, achieving the desired level of pulverization or blending. The high-shear mixer utilizes the high-speed rotation of a specialized rotor to generate a vacuum, continuously and uniformly drawing powder into a rapidly flowing liquid stream; the materials are then instantly and evenly dispersed and mixed within the shear chamber. Since the liquid and powder remain separate until the moment of mixing-at which point the powder is introduced into the liquid flow in a dispersed state-the likelihood of powder agglomeration is significantly reduced.
Key factors influencing the mixing process include material properties (particle size, specific gravity, viscosity), loading volume (typically a fill rate of 40%–60%), rotational speed and mixing duration (speed usually ranges from 5 to 20 rpm), and the smoothness of the hopper's inner walls.
