Why the hot melt glue in the glue pot of the banding machine can't be melt ?

- Mar 11, 2020-

Sometimes when we find in the glue pot of the edge banding machine, the glue on the surface seems to melt after adding hot melt adhesive, but many rubber particles in the middle of the glue pot and near the bottom of the pot remain as they are, and they are not melted

To find the reason, we need to check the following steps,

1. First, determine the heating method of the glue pot. Generally, there are at least two or three heating units in the glue pot. The main heating unit is directly below the glue deposit. It can be composed of a single heating plate or multiple heating tubes. A group that is not hot can cause what you said. The other group is generally outside the main rubber shaft. The main heating area is the area where the glue is applied. If it is broken, there will be uneven heating. The solution is very simple. Remove the terminal wires of each group of heating plates or heating tubes, and use a multimeter to measure the resistance of each group. If it is burned for an open circuit, replace it to eliminate the fault.


2. Design flaws. I remember that I did a test for this. A flat-bottomed plastic pot and a plastic pot with a thermal conductive strip melted the uniformity of the glue for 15 minutes. The latter has obvious advantages. The solution is to add two aluminum bars to the bottom of the glue pot and fix them with bolts, which can play a good role in heat conduction and solve the hard core problem.


3. There is another a problem about the temperature sensor. If your temperature sensor's temperature measurement point is not appropriate, it will incorrectly transmit the temperature signal, causing the wrong command output of the temperature controller, and increasing the time for the hot melt adhesive to melt. The correct temperature measurement point should be the temperature of the glue solution between the two heating units. Remember that the temperature of the surface of the glue pot cannot be measured. Since the heat conductivity of aluminum is much greater than the glue, the measured actual temperature deviates too much from the true temperature of the glue. . The solution is to remove the sensor with an unreasonable position. According to the installation position of the machine, find a location that does not hinder the work of other components, and the temperature measurement point is close to the low temperature area of the glue pot, which is the vicinity of the area where the glue does not melt. , Install the sensor, you can get a good improvement.