A thermoplastic which has a random molecular structure. Examples are ABS, Polycarbonate, and Polystyrene.

Amorphous vs. Semi-crystalline are two types of plastics that should bear full scrutiny and research early on in the product design phase, which will avoid costly pitfalls once you get to the manufacturing process.

The decision to use either Thermoset Plastics or Thermoplastics is not as simple as it seems when it comes to ultrasonic welding of plastic parts.