Method for evenly distributing plastic melt in a hot runner system using strain gauges

• Main Authors: Lawless, III, William Francis, Burns, Brian Matthew, Pollard, Rick Alan, Altonen, Gene Michael
• Format: Patent
• Language: English
• Published: 21.01.2020
• 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 hot runner injection molding apparatus, and method of use, is disclosed in which strain gauges are provided in the temperature zones of the hot runner injection molding apparatus and a hot runner controller creates a target strain profile, detects deviations from the target strain profile in any temperature zone based on the strain readings provided by the strain gauges in each temperature zone, and instructs correction of deviations from the target strain profile in any deviating temperature zone by adjusting the heat produced by a heater or heaters in the deviating temperature zone. The target strain profile may be based on a median or average of strain readings provided over time by the strain gauges in each temperature zone. A hollow installation tube for placing the strain gauges in the hot runner injection molding apparatus is also disclosed.