Solutions to common problems with dispensing heads

1. The glue nozzle of the dispensing valve is clogged.

Reason: The pinhole of the automatic dispensing machine is not cleaned cleanly, impurities are mixed in the glue, there is a hole blockage, and incompatible glue is mixed, resulting in less glue nozzle output or no glue points.

Solution: Replace the clean needle and good quality patch glue, and do not make a mistake in the brand of patch glue.

 

2. The glue valve of the dispensing valve leaks.

Reason: The needle diameter of the dispensing machine is too small, which will affect the bubble discharge action when the glue valve starts to be used, affect the flow of the liquid, cause back pressure, and cause the glue valve to drip shortly after it is closed.

Solution: This problem can only be solved by replacing a larger needle. In addition, after the dispensing valve is closed, the air in the liquid will drip. Try to remove the air in the liquid in advance, or use glue that is not easy to contain bubbles, or centrifuge the glue before use.

 

3. The flow rate of the dispensing valve is too slow.

Cause: The dispensing machine pipeline is too long or too narrow, the air pressure at the nozzle is insufficient, and the dispensing flow rate is too slow.

Solution: Change the dispensing machine pipeline from 1/4" to 3/8". If it is not necessary, the pipeline should be as short as possible. In addition, the glue port and air pressure should be improved to speed up the flow rate.

 

4. There are bubbles in the liquid of the dispensing valve.

Cause: Due to excessive fluid pressure and short valve opening time, the dispenser may infiltrate air into the liquid, resulting in bubbles.

Solution: Reduce fluid pressure and use a tapered bevel needle.

 

5. The dispensing size of the dispensing valve is inconsistent.

Cause: The pressure cylinder or air pressure of the dispensing machine storing fluid is unstable, resulting in uneven dispensing and inconsistent size.

Solution: Avoid using the low-pressure part of the pressure gauge. The control pressure of the glue valve should be at least 60 pounds per square inch to ensure stable glue discharge. Then, check the glue discharge time. Less than 15/1000 seconds, the glue discharge is unstable, and the longer the glue discharge time, the more stable it is.

 

6. Wiredrawing of the dispensing valve.

Reason: During the dispensing process of the dispensing valve, due to the high viscosity, sometimes the drawing will affect the dispensing quality.

Solution: The high viscosity glue is difficult to spit out, and the fluidity is weak or almost non-existent. If the company has strict requirements on product quality, it can be considered from the hardware aspect. The dispensing valve is equipped with a valve specially designed for high viscosity fluids, such as an imported spiral valve, and the viscosity value of the glue is provided to the manufacturer. The manufacturer will help you match the glue according to the viscosity value to achieve a good dispensing state. Of course, the price of the high viscosity spiral valve will be more expensive, but it will help you solve the drawing phenomenon very well. When using it, either heat the glue, open and close the glue, or pull it diagonally upward.