Four methods for controlling the amount of glue in a dispensing machine
Release Date：2017-06-26
Four methods for controlling the amount of glue in a dispensing machine
1. Time pressure method. This method was first used in SMT, which obtains a predetermined amount of glue and the diameter of glue points by controlling time and air pressure. Usually, the coating amount increases with the increase of pressure and time, and the volume of glue droplets distributed is a function of the time the glue pressure is applied to the syringe. 2. Screw pump allocation method. This method uses rotary pump pressurization technology to drive the adhesive solution for coating, with high repeatability and accuracy, and can be used for coating adhesives with the worst coating performance. It uses a motor to drive the screw to rotate a precise distance or angle, and its working mode can produce droplets with better repeatability than the time pressure method. 3. Piston pressure type. This method uses a closed-loop glue dispensing machine that relies on matched pistons and cylinders to work. The piston moves downward in the cavity to push the glue solution, and the amount of glue applied is determined by the volume of the cylinder, resulting in a certain amount and shape of glue. The advantage of this method is that it is faster than the previous two methods, and can transport high viscosity fluids. By controlling the air pressure, the outlet flow rate can be adjusted, and the time spent on squeezing glue will not change due to the size of the drop point. Therefore, it can maintain a constant work efficiency, make it easier to achieve fast, accurate, and repeatable glue dripping, and can be applied to glue liquids of different viscosities. The disadvantages are: the equipment needs to be cleaned frequently, the cleaning process is complex, and the equipment investment is also large; This method is not suitable for dispensing when the adhesive contains large particles. 4. Fluid jet method. The basic principle of this method is similar to that of inkjet printers, which apply a sufficiently large force to the fluid to enable the material to automatically separate. The adhesive liquid fills the gap between the nozzle and the syringe under the action of colloidal pressure. Firstly, the nozzle moves upwards under the action of air pressure and stays at the highest position for a suitable period of time. The nozzle moves downwards under the action of spring force, and the end spherical surface collides with the base, cutting off the flowing adhesive liquid. The adhesive liquid at the lower end of the spherical surface is ejected at high speed from the nozzle, forming adhesive droplets. Then the needle stays at the lowest position for a period of time, and then moves upwards to start the next cycle of motion.
Shenzhen Yapude Technology acts as an agent for the American Techcon brand, selling all Techcon dispensing equipment and consumables, providing technical services. If needed, please feel free to consult at 0755-29955243
