Articles

Hot Melt Troubleshooting

Poor Adhesion

Possible Cause

  1. Improper adhesive wet out due to temperature too low.
  2. Too little adhesive amount
  3. Coated or difficult to bond substrate

Substrate Pop Open

Possible Cause

Adhesive on 1 substrate

  1. Poor substrate penetration due to adhesive temperature too low.
  2. Too little adhesive amount

Adhesive on 2 substrate

  1. Adhesive temperature too high
  2. Poor compression
  3. Too much adhesive applied
  4. Substrate shifting during compression

Charring/Gelling of adhesive in heating tank

Possible Cause

  1. Tank temperature too high
  2. Faulty heating control
  3. Overheated adhesive on side wall
  4. Poor heat stability adhesive
  5. Adhesive oxidized
  6. Incompatible adhesive

Smoke / Fume

Possible Cause

  1. Adhesive temperature too high
  2. Exposure to air

Bubble in adhesive

Possible Cause

  1. Evaporation of moisture in substrate
  2. Air leaking into pump
  3. Cavity of pump

Splash of adhesive from substrate

Possible Cause

  1. Adhesive temperature too high
  2. Air pressure too high
  3. Incorrect nozzle position

Stopped / Reduced of adhesive flow

Possible Cause

  1. Clogged nozzle
  2. Blocked filter
  3. Temperature or pressure too low

Stringing of adhesive

Possible Cause

  1. High viscosity of adhesive
  2. Application temperature too low
  3. Nozzle too far from substrate
  4. Pressure too low
  5. Poor nozzle shut-off
  6. Adhesive exceeded the pot life