Layer Adhesion

Also known as: Interlayer Bonding, Z Strength

intermediate Print Quality

How well layers bond together, affecting print strength in the vertical direction.

Layer adhesion is how well each printed layer bonds to the layer below it. Poor adhesion causes weak prints that break along layer lines.

Why It Matters

3D prints are weakest in the Z direction (vertical). Good layer adhesion reduces this weakness.

Factors Affecting Adhesion

Temperature

  • Higher temp = better bonding
  • Layers fuse better when hot

Cooling

  • Less cooling = better adhesion
  • Trade-off with overhangs

Layer Height

  • Thinner layers = more contact = better adhesion
  • Thicker layers = less bonding area
  • Slower = more heat transfer = better bonding

Improving Layer Adhesion

  1. Increase temperature
  2. Reduce cooling fan
  3. Use thinner layers
  4. Slow down print speed
  5. Use enclosure (keeps ambient warm)
  6. Dry your filament

Testing

Print a tensile test bar and try to snap it. Good adhesion = clean break across layers, not splitting between them.