a method and device for recovering linear polyesters , such as pet and pbt , from polyester waste of the most varied form , in a continuous manner , in which undried or not dried - through waste is melted , the polymer chains being hydrolytically degraded by adhering moisture , and in which diol , corresponding to the basic constitutional unit of the polymer , is added to the melt resulting in glycolytic degradation , and the melt so treated is further condensed to the desired degree of polymerization .