What is AMALPHA?

AMALPHA bonding mechanisms are little affected by the chemical properties of resin since the bonding is mechanical rendered by the “anchor effect.”

Theoretically any resin can be used to achieve this bonding if molten resin can be forced into, and solidify in, a microscopically roughened surface profile of metal.

Resin-to-metal bonding matrix

  Al SUS Cu
PA6T - -
PA11 - -
PA12 - -
SPS - -
PPA - -
PP -
NBR - -

◎ : Bonding by injection molding → Fracture of resin
○ : Bonding by heat pressing → Fracture of resin
△ : Bonding by injection molding or heat pressing → Fracture of resin does not occur. The bonding strength is 1 MPa or higher.
- : Evaluation data not available
The data shown above contains users’ evaluation results.

Notes on molding

Fluidity of resin

If the fluidity of resin is low, the resin cannot be fully forced into the microscopically roughened surfaces of the metal, resulting in poor bonding. Ensure sufficient fluidity of the resin by raising the mold temperature or by other means. Favorable molding conditions for AMALPHA are those under which the resin is likely to form burrs.

Linear thermal expansion coefficient of resin

Resins of a high linear thermal expansion coefficient may develop cracks after molding due to shrinkage of the resin during cooling and resultant internal stress. Use of a glass filler reduces the linear thermal expansion coefficient of resin and raises its strength to facilitate achieving favorable bonding.

Weldless molding

Using weldless molding makes it possible to bond hard-to-bond resins.

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