METHOD FOR INHOMOGENEOUS TEMPERATURE CONTROL OF PREFORMS

• Main Authors: SCHILL, Alexander, ORLICH, Bernhard, WIESE, Arne
• Format: Patent
• Language: English; French; German
• Published: 21.03.2018
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

A method for heating a preform that is rotationally symmetric about its longitudinal axis, has a standard thread, and is made of a thermoplastic material. During heating, the preform is temperature conditioned to be formed into a container having a non-circular cross-section transverse to a longitudinal axis of the container by blow-molding. The preform is provided with a temperature profile along a circumference of the preform such that areas of the preform are differentially heated in a radial direction of the circumference of the preform. The standard thread of the preform is aligned in a predefined target position before the areas of the preform are differentially heated. The preform is rotated into alignment. An alignment element engages in the standard thread of the preform and thereby prevents further rotation of the preform as soon as the alignment element comes in contact with a predetermined contact surface in the standard thread.