Melting temperature

The melting temperature is the temperature at which a material transitions from a solid to a liquid or highly softened state. This transition is an important physical process that characterises the thermal properties of a material.

Melting point. In semi-crystalline plastics, the melting temperature is defined as the temperature at which the crystalline regions of the material begin to melt and transition into the liquid state. These crystalline regions are ordered structures within the plastic that lose their order at the melting temperature and become liquid.

Amorphous thermoplastics, by contrast, do not have a clearly defined melting temperature. Instead, they have a glass transition point at which they transition from a hard, glass-like state into a softer, rubber-like state. This transition is less abrupt than the melting process in semi-crystalline plastics and characterises the thermal behaviour of amorphous materials.