Abstract: A nibbler for severing a heat softened plastic parison into small, readily re-used parison pieces or sections during molding machine downtimes. The nibbler has a pair of cooperating knives which move towards and away from each other and it is preferably permanently mounted to the molding machine. When the molding operation temporarily ceases, the nibbler is moved into registration with the parison and the latter is severed by the knives. The knives are positioned above a horizontal conveyor for the finish molded objects which transports them away from the machine. The severed parison sections are separated from the objects by passing both over openings which have a sufficient size so that the sections can drop therethrough while the finish formed objects pass thereover.