How to troubleshoot if the glue pot cannot produce glue or if the glue supply is not smooth? 6-step inspection of the glue system on the book binding machine

If the glue pot is not producing glue or the glue supply is not smooth, don’t rush to replace the glue -80% of the problem lies in the “feeding/dispensing system” or “temperature control”.The most important thing to check first is whether the glue pot has truly reached the working temperature and whether there are carbonization lumps blocking the discharge port in the glue tank. Go through the 6 steps of troubleshooting in order from easy to difficult, and in most cases, you can locate it yourself.

1、 First, confirm that the glue pot is really warm

The training repeatedly emphasized:90% of after-sales problems come from equipment temperature control failure.The actual temperature displayed at 160 ℃ may only be 100 ℃, and the glue cannot be applied without melting.

• Measure the actual temperature of the glue pot with a thermometer and compare it with the working temperature on the process card (book glue is commonly around 160-180 ℃, subject to the process card);
• If the actual measurement is much lower than the set value, it is a fault in the heating rod, temperature control probe or relay. Repair the temperature control first and then discuss other issues.

2、 Check if the adhesive groove is carbonized, clumped, or blocked

If the glue pot is not cleaned for a long time, a layer of carbonized hard blocks will accumulate at the bottom of the pot and the discharge port, which will make the discharge port narrower and narrower, and eventually no glue will be discharged directly.

• Open the glue pot and check for blackening and hardening of the pot wall, discharge port, and conveyor hose;
• Clean the pot according to the specifications (see the article “How to clean the glue pot when changing glue and changing lines” in this series), and do not use hard objects to scratch the pot violently.

3、 Check if the glue/liquid level is sufficient

If the liquid level is too low, the pump cannot suction the glue, and it will intermittently fail to apply.

• If the liquid level in the glue pot is lower than the pump port, air pockets will form, causing the glue supply to stop intermittently;
• Before starting the machine, fill it to the normal liquid level and observe whether continuous dispensing of glue has been restored.

4、 Check the glue pump and pipeline

• Gear pump/rotor jamming, and cold clots in the pipeline will result in ‘glue not being able to come out’;
• Listen for any abnormal noise from the pump, feel for any local overheating (blockage) in the pipeline, and if necessary, disassemble and clean the pump.

5、 Check if the fluidity of the adhesive matches the machine speed

The opening time and viscosity of the glue should match the speed of the machine: fast gel for low-speed machines, and long opening time glue for high-speed machines.

• If the viscosity is too high and the machine speed is too fast, there may be a situation where “it can be supplied but the coating is not even, and it looks like no glue is coming out”;
• When the selection does not match, it is not due to equipment failure, but rather due to incorrect glue type and rhythm (opening time window: low speed about 15-20 seconds, medium speed about 5-10 seconds, high speed about 2-7 seconds, subject to the process card).

6、 Exclude the ‘fake glue that cannot be glued’ on the back of the book

Sometimes the glue pot produces glue normally, but the book back is still empty. The problem isInsufficient back trimming and uneven clamping of the book block during millingThe glue cannot penetrate, it looks like there hasn’t been any glue applied.

• In this situation, first check the previous process (book core sorting, milling depth, and degree of roughening), don’t just focus on the glue pot.

Summary: Remember the sequence of investigation

1. Temperature gun calibration actual temperature → 2 Check for carbonization blockage → 3 Check the liquid level → 4 Check the pump and pipeline → 5 Check the adhesive type and machine speed → 6 Arrange the previous process again.

Most cases of ‘no glue’ can be solved by the first two steps. If the boiler still cannot be turned on after cleaning and temperature calibration, please contact the equipment supplier or Sunlife technology againModel, adhesive model, measured temperature, on-site videoTogether, we can locate it faster.

Explanation: This article is about troubleshooting knowledge. The specific working temperature and opening time are subject to the accompanying process card; Do not extend unverified device parameters or certification statements.