tige d'élongation

CONT: La préforme est alors réchauffée puis bi-étirée par étirage axial à l'aide d'une tige d'élongation et par étirage radial avec soufflage à l'air comprimé.

CONT: Extrusion stretch blow moulding (ESBM). A parison is extruded and as the preblow mould closes, a mandrel descends to form the bottle neck. The parison is subsequently pinched and inflated, then conditioned at the optimum temperature for orientation in the next stage. Transfer of the blown and conditioned preform to the stretch-blow mould takes place; fabrication of the finished part is achieved by stretching in the circumferential direction (pneumatic inflation) and in the longitudinal direction (mechanical push-rod), followed by rapid cooling to prevent relaxation of the (biaxial) molecular orientation.