Method of classifying a plastic

A method of classifying a plastic, wherein

• b) the plastic is plasticized by supplying plasticizing energy in the form of mechanical and/or thermal energy with an increase in a temperature of the plastic from an initial temperature value to a final temperature value,
• h) an infrared radiation emitted by the plastic is detected by measurement means, and
• i) a plastic group containing the plastic is identified on the basis of the detected infrared radiation.

A method of classifying a plastic, wherein

• b) the plastic is plasticized by supplying plasticizing energy in the form of mechanical and/or thermal energy with an increase in a temperature of the plastic from an initial temperature value to a final temperature value, and
• j) identification information about the plastic is obtained from at least two different sources, wherein at least one of the at least two different sources is measurement at an apparatus used for plasticizing the plastic and that on the basis of the identification information a plastic group containing the plastic is identified and preferably the plastic is identified.