The glue dispensing machine sends compressed air into the syringe or glue bottle, presses the glue into the feed tube connected to the piston chamber, and uses pressure to perform the dispensing operation. When the piston is in the upward stroke, the piston chamber will be filled with glue; When the piston pushes down the dropper needle, the glue will be pressed out from the nozzle under pressure. The amount of glue dripped is determined by the distance of the piston's downward movement and can be manually adjusted or controlled through programming.

Glue dispensing machines can be divided into two working modes:

1. Manual dispensing: The principle of using a manual dispensing machine to dispense glue onto electronic products is simple and cost-effective. The disadvantage is that the dispensing efficiency is slow and it consumes a lot of labor.

2. Automatic dispensing: The principle of LCD dispensing machine is to use air pressure to push out the adhesive liquid within a set time. The instrument controls the drip time each time to ensure that the drip volume is the same. As long as the air pressure, time, and appropriate nozzle are adjusted, the drip volume can be easily changed each time, making it convenient and accurate.

The dispensing machine is a significant transition from manual to automated. It includes the writing of mechanical, electrical, and PLC programs. It effectively demonstrates the extraordinary application of mechatronics technology. It is the best embodiment of mechatronics integration towards intelligence, modularity, and greenness. However, many factories and enterprises now purchase dispensing machines and their operators lack experience and relevant training, which often affects the dispensing effect of the machines due to some minor issues not being properly addressed and handled during the production process.