Dispensing products often meet such questions: dot size can't be controlled, having delay glue, infiltrating, etc. We should study the technical parameters to find good solution ways to solve these problems

1、Factors affecting the dispensing volume

  【1】The opening diameter of the needle【2】Air pressure  【3】The dispensing time

2、Air pressure

When the dispenser provides a certain amount of pressure to the syringe and dispensing tip,  the glue will flow  out. The pressure is higher, then the dispensing volume is bigger. But if air pressure is too high, then the glue flow will be more than requirement. And there will be more reject. if the air pressure is too low, sometimes the dispenser  can't discharge anything, sometimes the flow which be pumped out isn't continuous. So we should adjust the pressure according to the characteristics of the glue.

3、The size of the dispensing tip

You should select suitable needle size according to the size of the dots required. Generally the needle size should be half of the dot's size.

4、The distance between the needle and the work-board

　Different dispensers often select different dispensing tips. Before working, you should adjust the distance between the needle and the work-board. 

5、Glue's viscosity

　The viscosity of the glue will directly affect the product quality. If the viscosity is high, the dispensing point will be small; if the viscosity is low, the dispensing point will be big, even covering the full product. So we should select different pressure and dispensing time according the viscosity.

6、Glue temperature

　Generally, the preservative temperature of epoxy resin  is 0～5℃. Half hour before using the glue, we pick it up and make its temperature be same with the surroundings. The  working temperature of epoxy glue is 23℃～25℃. If the working temperature is lower than normal, the viscosity will become higher and the dispensing qty will become less, sometimes delaying of flow will occur.  When other  setting all be same, only the temperature have a difference of 5℃, the dispensing qty will be an error at 50% ratio. Then we must control the working temperature when using the glue .

7、Curing time and dealing.

     The suppliers will offer the curing time with the glue, we can operate as their requirement.

8、 Bubble

      It's serious if there are bubbles in the glue. We should clean the bubbles out before the dispenser works.

9、How to select the accessories for special fluids.

     Instantaneous Adhesive： For the low viscosity instantaneous adhesive we can use the Teflon  tips. If the viscosity is high, we should use the taper tips. If it requires flexibility, then we should use the flexible PP tips.

     UV adhesive: Using the amber barrel/syringe is a good choice for UV adhesive.

     Optical light-sensitive adhesive: We should choose the black syringe for it.

     Anaerobic adhesive: We should use the 10CC syringe for it.

     Tin paste liquids: We can use the safe piston and taper tip.

To adjust the parameters, we should do it according to the actual situation.  It will affect the whole product that any parameter is changed. When questions occur, usually there are many reasons. We should check every possible reason.