Thermo mechanical method can be used in PET fiber wastes, polypropylene wastes, polyamide wastes, etc. Thermo mechanical method is based on re-melting of thermoplastic wastes to obtain re granules. Re granules can be used in staple fiber production or in plastic industry. Due to the degradations and viscosity drops, re-granules are used in staple fiber production. Solid state post condensation can be used to increase viscosity, however the process requires very high energy.