a process is described for treating waste plastics material to provide at least one on - specification fuel product . plastics material is melted and then pyrolysed in an oxygen - free atmosphere to provide pyrolysis gases . the pyrolysis gases are brought into contact with plates in a contactor vessel so that some long chain gas components condense and return to be further pyrolysed to achieve thermal degradation . short chain gas components exit the contactor in gaseous form and proceed to distillation to provide one or more on - specification fuel products . a pipe directly links the pyrolysis chamber to the contactor , suitable for conveying upwardly - moving pyrolysis gases and downwardly - flowing long - chain liquid for thermal degradation .