Dispensing Anaerobic Adhesives
Dispensing Anaerobic Adhesives are widely used in manufacturing and assembly due to their excellent bonding capabilities, chemical resistance, and ability to cure quickly in the absence of oxygen. These materials are essential for securing metal parts such as fasteners, bearings, and flanges, especially in environments where vibration, pressure, or thermal cycling could otherwise loosen connections or cause leaks.
Effective dispensing of anaerobic adhesives and sealants requires careful attention to application technique, material compatibility, and process control to ensure optimal performance and avoid premature curing.
What Are Anaerobic Adhesives and Sealants?
Anaerobic adhesives are single-component, solvent-free materials that cure through a chemical reaction triggered by metal ions in the absence of oxygen. This makes them ideal for:
- Threadlocking: Preventing fastener loosening due to vibration
- Retaining: Securing cylindrical parts such as shafts, pulleys, and bearings
- Sealing: Preventing fluid or gas leaks in threaded pipe joints
- Gasketing: Creating form-in-place seals between rigid metal components
They remain in liquid form when exposed to air but rapidly harden once confined between two metal surfaces, forming a strong, durable bond.
Challenges in Dispensing Anaerobic Adhesives
While anaerobic adhesives offer high performance, dispensing them accurately and efficiently can be challenging due to their reactive nature:
1. Premature Curing
Anaerobic adhesives can begin to cure if they come into contact with metallic dispensing components. This reaction can cause blockages or equipment damage if not managed properly.
2. Contamination
Even minor contamination such as touching a nozzle to a metal surfaceb can introduce metal ions that initiate curing. Similarly, impurities in air lines, hoppers, or transfer lines can lead to unwanted reactions.
3. Material Sensitivity
Different formulations of anaerobic adhesives cure at varying speeds and under different conditions. Selecting the wrong adhesive or improper environmental control can result in slow cures or poor adhesion.
Best Practices for Manual Dispensing
When applying anaerobic adhesives manually:
- Cut the nozzle carefully to control flow and prevent over-application.
- Avoid touching metal surfaces with the nozzle tip to prevent localized curing.
- Store containers upright and sealed when not in use.
- Replace caps immediately after use, especially in workshops where metal particles or activator sprays may be present.
- Use clean tools and a controlled workspace to reduce contamination risks.
Best Practices for Automated Dispensing
In automated production environments:
- Use non-metallic or chemically treated dispensing paths to avoid initiating cure within the system.
- Ensure proper material handling when filling tanks or reservoirs dipsticks, funnels, and transfer lines should be clean and free of reactive materials.
- Filter pressurized air supplies to remove oil, water, or particles that may affect the adhesive.
- Follow routine maintenance and cleaning procedures recommended by the equipment manufacturer to minimize buildup and ensure consistent flow.
Industrial Applications
Dispensing anaerobic adhesives and sealants is common in industries such as:
- Automotive: For threadlocking, gasketing, and magnet bonding
- Aerospace: For vibration-resistant fastener sealing
- Electronics: For retaining components and sealing enclosures
- Manufacturing & Heavy Equipment: For retaining shafts, sealing pipe threads, and forming gaskets
Each application demands precise control over the volume, placement, and consistency of the adhesive for optimal performance and reliability.
Dispensing anaerobic adhesives and sealants requires a careful balance of chemistry, equipment compatibility, and process discipline. Whether applied manually or through an automated system, maintaining clean dispensing paths, avoiding metal contact, and preventing contamination are essential for achieving strong, reliable bonds. As manufacturing demands continue to grow, optimizing adhesive dispensing processes plays a key role in enhancing product quality and reducing production downtime.