Abstract: A method and apparatus for producing plastic products from waste materials by: cutting into pieces a thermoplastic material having a loss factor higher than 0.005 such as to have a high absorbence of radio-frequency radiation, mixing the pieces with at least one other particulate material, depositing the mixture on a supporting surface; applying radio-frequency radiation to the mixture sufficient to soften mainly the outer surfaces of the pieces of thermoplastic material by dielectric heating, while applying pressure to the mixture to bond the mixture together by sintering; and removing the sintered mixture from the supporting surface.