INJECTION MOLDING SCRAP RATES DROP FROM 7% TO 1% when a machine is retrofit with a new computerized closed-loop controller, says CENTURY MOLDED PLASTICS, Glenview, IL, USA.
Century Molded Plastics specializes in high volume, thin wall parts molded at cycle times as low as 3 seconds. "Low cycle time parts like these place an exceptional amount of strain on both the machine and control," says Ken Lemanski, plant manager. "Because the machine is working harder and faster, failures can become more frequent. The injection profile must be maintained to a high level of accuracy or problems are sure to occur."
Century upgrades a 23,000-kN (260-ton) Van Dorn machine by retrofitting it with a Scoremaster EL controller from SOLID CONTROLS. This controller provides 10 stage closed-loop injection velocity control. The user can define the conditions that will trigger a fault, normally a pressure or injection velocity outside of the expected range.
Century typically programs the controller to stop the machine immediately if a fault occurs which means that only one bad part is produced. This was a key factor in reducing scrap on low cycle time parts by 86%.
The new controller is also capable of subtle adjustments in the injection cycle. For examples, injection is slowed when the melt flows near cores to keep cores from moving. For details, contact Solid Controls Inc. 820 South Fifth St., Hopkins, MN 55343. Phone (612) 933-9053; fax (612) 933-8961; email Solid2000@aol.com or use the Request Info button.
Solid Controls, Inc., 820 South 5th Street. Tel: 952-933-9053; Fax: .