3 Reasons You May Have Air Bubbles in Your Hot Melt Adhesive (and what to do about it)

June 23, 2022


Who doesn’t love bubbles? Whether they’re in a glass full of champagne or a warm, relaxing tub – it’s always a ‘yes’ from the team at Chicago Glue and Machine. But air bubbles in hot melt adhesives? Now that’s a hard ‘no’. If you’re dealing with unwanted bubbles, here are three culprits and how to remedy each.

  1. Bubbles in adhesive bead It is not uncommon for air to become trapped in beads of glue if the tank is allowed to run dry or, less often, when switching adhesive in your hot melt equipment. As old adhesive is drained, little to no glue remains in the tank. When the pump begins to cycle, it introduces air into the equipment’s hoses. That equipment dispenses the air – as bubbles – with the new adhesive that fills the tank. Bubbles appear in the adhesive bead until enough adhesive is run through the system to push out all the air trapped in the hoses.
    REMEDY: The easiest way to fix this issue is to not allow your adhesive tank to run dry. When you do need to drain the tank, do so with the hoses disconnected or from the drain valve.
  2. Bubbles on the applicator  If bubbles are appearing on the applicator of your holt melt equipment, you may have a damaged or open valve that has allowed air into the system.
    REMEDY: Check the condition of your valves and replace any valve that is defective. Not sure how to tell? Call the service team at CGM and we’ll help you troubleshoot.
  3. Bubbles in the tank Overheating hot melt adhesive can cause thermal decomposition and result in bubbles being created within the tank.
    REMEDY: Check that the temperature of your equipment is set to the correct setting. Depending on the type of adhesive you are using, application temperatures range from 212° to 450°F (100 to 230°C). Find the correct recommended temperature for your adhesive on the technical data sheet (TDS).Our experts are available 24/7/365 to help you get to the bottom of any adhesive issues that bubble up! Contact our service team at 1-800-419-GLUE or complete the contact form HERE.