Automated molding technology for thermoplastic injection molding

• Main Author: RUSSELL G. SPEIGHT
• Format: Patent
• Language: English
• Published: 23.05.2001
• Edition: 7
• 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 the automated optimization of an injection molding machine set-up process, the machine for manufacturing injection molded parts and including an injection screw and a configurable injection velocity, the screw having a displacement, comprising the steps of (1) manufacturing one or more parts with the machine, (2) defining as a first pressure the end of velocity control phase pressure and as a second pressure the holding time pressure, (3) defining a linear relationship between packing/holding pressure and time consistent with the first pressure and the second pressure, between the first pressure and the second pressure, (4) defining the packing time as a time of maximum difference between measured melt pressure and the linear relationship, or as the switchover point if measured melt pressure increases after the switchover point, (5) determining a first screw displacement being the minimum displacement of the screw before the packing time within a packing/holding phase and a second screw displacement being the displacement of the screw at the packing time, and (6) calculating the kickback from the difference between the first and second screw displacements, thereby allowing a determination of the kickback from measurements of the screw displacement at packing time.