Heat Treatment

What is Heat Treatment of Plastic?

Heat treatment of plastics is a procedure to remove internal stresses of the material, improve its thermal properties, polish it and to ensure the reduction of cracking and crazing during the production process.

Heat treating plastics is also known as normalising or annealing;

  • Normalising of plastic helps improve the mechanical properties refining the material and improving its performance. Parts are heated to a high temperature and cooled quicker than the annealing process to room temperature outside the ovens.
  • Complete annealing, or stress relieving annealing plastic, is to reduce the hardness of the material, and relieve the internal stresses and uneven structure. IPF heat parts to a low temperature for a period of time, then cool to room temperature within the furnace.


  • Less internal stress
  • Improved thermal properties
  • Reduction in crazing and distortion
  • Improved surface quality
  • Improved performance