Dual-liquid dispensing machine is a device that quantitatively conveys mixed glue to products through rationing, mixing and quantitative feeding of quantitative pumps. Quantitative pumps can be said to be the central processing unit of dual-liquid dispensing machine. The accuracy selection of feeding pumps directly affects the ratio accuracy and quantitative accuracy of dual-liquid dispensing machine. At present, dual-liquid dispensing machine is on the market. The main rubber supply pumps used are gear pump, screw pump and plunger pump (plunger pump requires strict cleanliness of working medium, complex structure, high price, difficult maintenance). In addition, the glue quantity discharged in straight line fluctuates very little. For glue discharged in straight line, gear metering pump is usually used. Users should re-use the glue according to different needs. Select the type of rubber supply pump.
Gear pump: The basic form is that two gears of the same size mesh and rotate each other in the closely matched housing. The inner part of the housing is similar to the "8" shape. The two gears are installed inside. The outer diameter of the gear and the two sides of the gear are closely matched with the housing. Material from the dispensing machine enters the middle of the two gears at the suction port and fills the empty space. Meanwhile, the rotation of the gear rubber supply pump moves along the shell, and finally discharges when the two teeth engage. This rubber supply pump adopts imported high quality alloy steel, which requires high processing technology. Its service life is also very long, but it is only suitable for glue without filler (because glue A will add some small solid particles, such as flame retardant and silicon powder, the wear of gears will become more and more serious when used for a long time. Once the clearance between gears is larger and larger, the glue volume will be less and less until it can not continue to use. Therefore, the selection of glue pump should focus on adjustment and selection after completion.
Screw pump: Rotary plunger pump is a new type of rubber supply pump based on the principle of rotating meshing displacement. Through matching stator and rotor screw, if there is a special need, this type of rubber supply pump can be selected. When the rotor rotates, the fluid is continuously extruded, and the glue is extruded more in the measuring chamber. In this respect, screw pump and piston pump have similar aspects, the main working parts are bias screw (rotor) and fixed bushing (stator). Because the special geometric starting points of the two parts form an independent sealing chamber, the medium flows uniformly from the axial direction, the internal flow velocity is low and the volume remains constant, the pressure is stable, and the product eddy current and pressure will not occur. Stirring, because the stator is made of many kinds of elastic materials, the choice of rubber pump to transport high viscosity fluid and medium containing hard suspended particles or medium containing fibers has characteristics that ordinary pump type does not have. Its flow rate is proportional to the speed. The rubber pump has few parts, compact structure, small size and simple maintenance. Rotor and stator are vulnerable parts of pump. The structure is simple and easy to disassemble and assemble.
Like gear metering pumps, screw pumps are continuous metering pumps. In the past, we usually used piston pumps to deliver glue with high viscosity and high number of fillers. However, due to the defects of piston pump in continuous rubber supply (several seconds after glue injection into piston pump chamber), screw pumps have gradually replaced them. Screw pumps are not as accurate as high-precision gear pumps, because they are specially used to transport glue containing fillers such as alumina, silica, quartz sand, etc., so according to the actual situation. Choosing rubber supply pump is the correct direction for consideration of the situation.