In automated dispensing systems, the adhesive preparation and feeding system is the foundation that guarantees consistent, precise, and high-quality glue dispensing. Whether in electronics, medical devices, or new energy sectors, ensuring stable glue supply is critical for product reliability. This article provides an in-depth look at adhesive preparation, feeding system types, design considerations, and maintenance.
Adhesive Preparation: The First Step to Success
Proper preparation is not merely filling glue into a container; it involves degassing, temperature control, and mixing to maintain material consistency:
Degassing: Air bubbles trapped in epoxy or other adhesives can cause intermittent dispensing or voids in the final product. Vacuum degassing removes these bubbles effectively.
Temperature Conditioning: Some adhesives, such as high-viscosity thermal pastes or UV glues, require pre-heating or refrigeration to maintain ideal viscosity and curing characteristics.
Mixing: Multi-component adhesives (like AB epoxies) must be thoroughly mixed to ensure uniform curing and strength.
Types of Feeding Systems
Pneumatic Pressure Feed
Using compressed air to push adhesive from containers, this method suits low to medium viscosity materials like UV glue. It is simple and cost-effective but sensitive to pressure fluctuations.
Mechanical Pumps (Gear or Screw Pumps)
These pumps provide steady, accurate flow for medium to high viscosity adhesives, such as silicones. Although more complex, they ensure precision and repeatability.
Pressure Tank Systems
Closed containers with adjustable pressure maintain a consistent flow, ideal for two-part adhesives requiring automatic mixing.
Heated Feeding Systems
Heating jackets or bands maintain adhesive at constant temperatures, lowering viscosity and preventing blockages, especially important for hot-melt adhesives.
Design & Maintenance Considerations
Pressure Stability: Regulate air or hydraulic pressure with feedback systems to avoid dispensing fluctuations.
Filtration: Use fine filters to prevent particles from clogging nozzles or pumps.
Tubing & Material Compatibility: Choose tubing with suitable diameter and chemical resistance to maintain flow without degradation.
Regular Cleaning: Prevent cured glue buildup by cleaning supply lines, especially with UV or fast-curing adhesives.
Troubleshooting Common Issues
Issue Possible Cause Suggested Solution
Inconsistent dispensing Air bubbles, unstable pressure Degas adhesive, stabilize pressure
Glue stringing High viscosity, improper tubing Pre-heat adhesive, adjust tubing
Clogging Residue buildup, poor cleaning Clean regularly, use filtration
Mixing ratio problems Incorrect pump calibration Recalibrate pumps, extend mixing tubes
Future Trends: Intelligent Feeding Systems
Emerging systems integrate sensors for pressure, flow, and temperature, paired with closed-loop control and MES connectivity. These advances enable dynamic adjustments, reducing waste and enhancing product quality.
Conclusion
Optimizing adhesive preparation and feeding systems is crucial for achieving precision and reliability in automated dispensing. Investing in appropriate equipment, design, and maintenance yields significant improvements in yield and reduces downtime.