Common Problems With Dispensing Machines

The most common problem encountered by dispensing machines is valve problems. The following are effective methods to solve the problems that often occur when using glue valves.
The situation of rubber valve leakage often occurs after the rubber valve is closed. 95% of this situation is caused by the use of a needle with a small caliber.
A needle that is too small can affect the flow of liquid and cause back pressure, resulting in the phenomenon of dripping shortly after the rubber valve is closed. A too small needle can also affect the exhaust bubble action of the rubber valve when it is first used. Simply replacing a larger needle can solve this problem. The conical inclined needle produces the least back pressure and the smoothest liquid flow. After the glue valve is closed, the air in the liquid will cause dripping and leakage. It is best 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.
Inconsistent glue size
When the adhesive output is inconsistent, it is mainly caused by the unstable pressure of the pressure cylinder or air that stores the fluid.
The intake pressure regulator should be set at 10 to 15 psi lower than the minimum pressure in the factory, The pressure used in the pressure cylinder should be above the middle of the pressure regulating gauge, and the use of pressure between the low pressure part of the pressure gauge should be avoided.
The control pressure of the glue valve should be at least 60psi or above to ensure stable glue output.
Finally, the adhesive release time should be checked. If it is less than 15/1000 seconds, it will cause unstable adhesive release, The longer the adhesive release time, the more stable the adhesive release.
Flow rate too slow
If the flow rate is too slow, the pipeline should be changed from 1/4 "to 3/8".
If the pipeline is not needed, it should be as short as possible.
In addition to changing the pipes, it is also necessary to change the rubber port and air pressure, which completely accelerates the flow rate.
Bubbles in the fluid
Excessive fluid pressure combined with too short valve opening time may cause air to seep into the liquid The solution is to reduce fluid pressure and use a conical inclined needle.
Glue blockage
This situation is mainly due to excessive moisture or repeated use of instant adhesive. Ensure the use of fresh instant glue. Thoroughly clean the pipeline with Aceton acetone without moisture. The air used should be confirmed to be dry and a filter should be installed between the air pressure and rubber valve system in the factory. If the above methods are still ineffective, nitrogen should be used.
Reasons for glue breakage during dispensing
Firstly, check if there is a problem with the glue (such as bubbles or particle deposits in the glue), which can cause the glue dispenser to break;
Secondly, is the dispensing controller working properly? Due to its abnormal operation or insufficient performance, there may also be issues of dispensing breakage.
UV adhesive
UV adhesive refers to UV curing adhesive.
Confirm the use of black pipes.
Do not directly add UV glue to the old UV glue of the pressure cylinder. First, release the original UV adhesive and then pour it into the empty pressure cylinder The UV adhesive inside the pressure cylinder often produces bubbles after a period of time, resulting in unstable adhesive release.
Selection of Needles
Selection method for dispensing needle:
1. Four guidelines: small point - small needle, low pressure, short time large point - large needle, high pressure, long time concentrated glue - inclined needle, high pressure, set time as needed for water-based liquid - small needle, low pressure, set time as needed.
2. Fluids that require special settings:
(1) Instant glue: For water-based instant glue, use a safety piston and Teflon lined metal needle. For thick instant glue, use a conical inclined needle. If flexibility is required, use a PP needle.
(2) UV glue: Use an amber needle cylinder, white piston, and angled needle tip (which can block ultraviolet rays).
(3) UV curable adhesive: Use a black opaque syringe, white piston, and UV resistant needle tip.
(4) Anaerobic adhesive: Use a 10CC syringe and a white PE universal piston.
(5) Sealant and paste like fluid: If using a white piston with severe rebound, please switch to a safe movable type and use an inclined needle.
Cleaning of epoxy resin
Epoxy resin (epoxy) should be automatically cleaned once per shift using a general toluene solvent storage pressure cylinder, and the more frequent the cleaning, the better.
shortcoming
This is a problem that arises in the market when trying to attract customers at low prices by reducing product costs. Therefore, when purchasing equipment, one should not only consider the price, but also consider the quality of the machine itself, ensuring the stability and operability of the product as much as possible, while ensuring the overall quality of the product.
1. The internal heat dissipation system of the machine is not very good, and there are already dispensing machines with good heat dissipation systems on the market;
2. Frequent crashes occur;
3. LCD anti black, garbled code may appear;
4. The position deviation of the machine (which may occur after running for a period of time) and the actual workpiece;
5. The static electricity treatment is not ideal enough (there is a large amount of static electricity generated);
6. The three-axis running speed is relatively slow, which is different from the actual speed required by the manufacturer;
7. The machine may run randomly under normal operation conditions (which is more dangerous to operate);
8. The use of Table in conjunction with a small glue dispenser may take some time, causing the Table's Relay to be broken down, resulting in a continuous leakage of glue in the signal output;
9. The program of the CF card is not stable enough, and industrial computers often burn down;
10. The load bearing capacity of the machine is relatively weak;
11. The connection of the driver board connector is relatively loose, which can easily lead to poor contact between the motherboard and the driver board (all plastic connectors).