To prevent dripping in a glue dispensing machine, first identify whether the cause is excess pressure, delayed valve shutoff, material flow, trapped air, or a worn or unsuitable nozzle. Then adjust one factor at a time: reduce or stabilize dispensing pressure, use the machine’s suck-back or anti-drip function if available, check the valve and nozzle, and confirm that the adhesive is within its recommended handling conditions. Test the changes with repeated dispense-and-stop cycles before returning to production. Because adhesives and dispensing systems vary, use the equipment and material supplier’s specifications as your limits rather than applying one pressure or timing setting to every setup.
Click here to get more.
A dispenser can continue to release adhesive after the control signal ends because pressure or material movement does not stop at the same instant as the command. In a pressure-fed system, air pressure may continue pushing material through the outlet, while a valve may take time to close or may not seal fully. Some adhesives also flow readily under gravity, especially when the reservoir, hose, or nozzle arrangement allows material to move toward the outlet.
Dripping can also result from trapped air, a damaged seal, residue around the valve seat, or a nozzle that is too large for the required deposit. Changes in temperature can affect adhesive viscosity, but the effect depends on the specific formulation. Start with observable checks before assuming that the machine needs a major adjustment or replacement.
Observe whether adhesive drips while the machine is idle, immediately after dispensing, or only after a longer production run. Note whether the material comes from the nozzle tip, a hose connection, the reservoir, or the valve body. The location and timing help distinguish a process-setting issue from a leak or component problem.
Before touching the system, follow the machine’s safety instructions and confirm the adhesive’s handling requirements. Relieve pressure as directed before opening or disconnecting a pressurized material path. If the adhesive is hazardous, reactive, or difficult to remove, use the handling and protective measures specified by its supplier.
For a pressure-fed system, check the regulator, air supply, and material pressure setting against the machine and adhesive requirements. If the pressure is higher than the process needs, make a small reduction and observe whether the deposit remains consistent while the post-dispense drip decreases. Do not compensate for a sealing fault by continually lowering pressure, since that may create inconsistent deposits without fixing the cause.
Where the machine provides suck-back, vacuum relief, or a reverse-pull function, consult its operating instructions and adjust the feature in small increments. Too little suck-back may leave material at the tip; too much can draw air into the nozzle or retract adhesive farther than intended. Use the shortest practical shutoff delay or suck-back setting that stops the after-flow without disrupting the next dispense.
Remove residue from the nozzle and valve area using a cleaning method compatible with the adhesive and equipment. Check the nozzle for blockage, damage, or an opening that is larger than the application requires. A smaller opening can improve control for some materials, but it can also increase resistance and may not suit high-viscosity adhesives or sensitive formulations.
Inspect seals, fittings, tubing, and the valve seat for wear, looseness, or material buildup. Replace parts only with components compatible with the adhesive and the dispenser. If material is leaking from a connection or valve body rather than the nozzle tip, isolate and address that leak instead of adjusting dispense timing.
If you are looking for more details, kindly visit SONGNA.
Air bubbles can make dispensing unpredictable because compressed air may expand after the valve closes and push adhesive out of the nozzle. Check the reservoir and material path for visible bubbles, loose connections, or an incomplete priming process. Prime the system according to its instructions, taking care not to introduce more air while loading or replenishing the adhesive.
Confirm that the adhesive is being stored, mixed, and used within the material supplier’s stated conditions. Avoid changing temperature or thinning the adhesive unless the supplier and equipment documentation permit it. Record the actual material temperature in °C during trials, since a temperature change may help explain a change in flow behavior.
After each adjustment, dispense onto a safe test surface and watch the nozzle after the control signal ends. Hold other settings constant so you can tell which change affected the result. As a practical starting check, run 10 consecutive dispense-and-stop cycles and record whether any cycle produces a visible tail or drop; this is a troubleshooting method, not a universal acceptance standard.
Log the material, nozzle size, pressure in kPa, temperature in °C, and valve or suck-back timing in seconds. The useful settings are those that produce the required deposit consistently without post-shutoff flow. If the process changes between operators, shifts, or material batches, repeat the check under the conditions that matter to production.
If dripping continues after basic inspection and controlled adjustment, review whether the machine configuration matches the adhesive and application. Consider the adhesive’s viscosity and chemistry, the required deposit size, dispensing frequency, hose length, nozzle geometry, and whether the process needs a positive shutoff or suck-back capability. The best configuration depends on the whole material path, not only the controller or dispensing head.
For procurement teams, request clear guidance on compatible adhesives, available valve and nozzle options, adjustment methods, cleaning requirements, and replacement parts. Ask how the supplier evaluates a proposed setup using your material and process details, and what information is needed before a recommendation can be made. A useful specification discussion should address both the target deposit and the conditions that cause after-flow.
If you cannot isolate the source of dripping, share the adhesive type, dispensing method, symptoms, current settings, nozzle details, and any relevant operating conditions with SONGNA. This information helps frame a practical discussion about machine configuration and process adjustments without assuming that one setting will fit every application. Where possible, provide a short description of when the drip occurs and whether it comes from the nozzle tip or another part of the material path.
Prevent dripping by locating the source first, then checking pressure, shutoff or suck-back behavior, the nozzle and valve, trapped air, and material conditions. Make one change at a time, document the settings, and verify the result through repeated cycles before resuming normal production. If the issue remains, review whether the dispenser, valve, and nozzle are suitable for the adhesive and required deposit, and consult SONGNA with your application details to discuss the next step.
If you are looking for more details, kindly visit How to Prevent Dripping in a Glue Dispensing Machine.