A small amount of adhesive buildup at the nozzle can be a warning sign of a larger dispensing issue. It may affect jetting performance, dispensing accuracy, and product quality.

Adhesive buildup at nozzle

Before changing your process parameters, take a closer look at the valve.

Here are 3 key areas to inspect when troubleshooting adhesive buildup: 

01 | Needle & Nozzle | Check for Wear

Repeated high-frequency impacts and continuous interaction with the adhesive can cause wear at the needle–nozzle contact surfaces.

Changes in contact conditions may affect impact consistency and jetting performance, making the original parameters less suitable for stable operation.

→ Check: Inspect the needle and nozzle for wear. Replace worn components and verify dispensing performance.

Axxon Mycronic offers complete valve cleaning procedure videos

02 | Seals | Check for Degradation

Prolonged exposure to chemically aggressive adhesives may cause seals to swell, become brittle, or deteriorate.

Seal failure under pressurized material supply conditions can result in leakage and chamber pressure changes, potentially disrupting adhesive supply.

→ Check: Inspect seals for damage and select sealing materials based on verified chemical compatibility. FFKM may be suitable for certain applications.

Axxon Mycronic offers complete valve cleaning procedure videos

03 | Valve Flow Path | Check for Contamination

Adhesive residue, cured deposits, or foreign particles can restrict material flow or obstruct the nozzle.

Sticking needle movement or insufficient lubrication may also compromise jetting performance.

Adhesive residue in flow path

→ Check: Clean the valve according to the approved maintenance procedure. Inspect precision components under a microscope and verify the condition and lubrication of moving parts.

💡 A Practical Maintenance Reminder

Maintenance frequency matters. As a starting reference:
• Continuous operation: At least weekly maintenance
• High-viscosity adhesives, such as silicone: Consider maintenance every three days

Actual intervals should be determined by the valve model, adhesive characteristics, and operating conditions.

One symptom. Multiple possible causes.

Adhesive buildup can also be influenced by material properties, process parameters, service life, and ambient conditions.

A systematic root-cause investigation is key to restoring stable dispensing performance. 

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