PURPOSE: To blend an additive in a polymer without melting polymer particles by suspending or entraining the thermoplastic polymer particles and the additive during blending in a gas medium using a continuous supply rapid/high strength mixer, and further, blending both materials in such a way that the additive is applied on the surface or the interior of the polymer particles.

CONSTITUTION: Thermoplastic polymer particles and an additive are blended while these materials are subjected to a suspension or entraining process in a gas medium using a continuous supply rapid/high strength mixer, and the additive is blended in such a way that it is applied to the surface or the interior of the polymer particles. This process is performed continuously without the use of a binder and in a short residence time in the mixer. The additive is blended into the granular polymer, e.g. polypropylene particles by colliding with each other at a high speed and thus the polymer particles and the additive are subjected to a rapid/high strength mixing process. The molten surface of the additive and/or the polymer prompts the blending of the additive into the polymer and the obtained polymer particles can be directly sold to a customer without the necessity of pelletizing them.