Process Control for Injection Molding
In injection molding, there are many ways to control the process from the manual operator who can start or stop the cycle at will to a fully automated process operating the machine without direct operator intervention. Often controls are based on a work parameter which is integrated with respect to time during the injection of plasticized material into a mold thus defining a work index which is used to control the molding machine. Typically, a monitor records specified variables during each cycle. Such monitoring systems, however, require manual changes to be made by an operator to obtain consistently uniform products. These days with computer control, the process can be completely automated. (RDC 11/6/2010)
US Patent 4,146,601, 3/27/1979,”Injection Process Control”
Recent US Patents
3/8/2011
7,901,601
Injection molding flow control apparatus and method
Vasapoli of Synventive Molding Solution, Massachusetts, controlled the flow of fluid material through an injection molding flow channel leading to a mold cavity using a pin having a longitudinal length being adapted for back and forth axial movement through the flow channel and a protrusion at a selected position along its length. (RDC 10/10/2011).
3/8/2011
7,901,601
Injection molding flow control apparatus and method
Vasapoli et al of Synventive Molding Solutions, Massachusetts,controlled the flow of through an injection molding flow channel leading to a mold cavity using a moveable pin with protusions along its length. (RDC 9/20/2011)
9/21/2010
7,798,799
Measurement control method of an injection molding machine
Shiozawa et al have developeda control method based on measuring the number of screw rotations it by a preset number of screw rotations to reach a defined position.
3/27/1979
4,146,601
Injection Molding Process Control
Bishop of HPM Corporation developed a control system based onintegration of a sensed injection pressure with respect to time from the beginning of an injection stroke until plasticized material in a mold reaches a predetermined pressure resulting in a work index. If a mold cavity pressure sensor indicates that the cavity is full, it stops the integration and may also reduce the injection pressure to a lower value, sufficient to supply additional material to compensate for shrinking due to cooling, yet not high enough to introduce strains, or cause flashing. (RDC 11/6/2010)
Recent Journal Articles
To get to the abstract or article, copy the citation and paste it into favorite search engine (ex. Google). The date is the date the entry was found.
11/12/20109
Step Response Identification Under Inherent-Type Load Disturbance With Application to Injection Molding
(11572–11581) Industrial & Engineering Chemistry Research 49 #22 (2010)
Liu et al of Hong Kong University of Science & Technology have developed a step-response identification method, proposed for practical application subject to inherent-type load disturbances; it is used for velocity control of an injection molding machine. (RDC 11/10/2010)
11/6/2010
Warpage Optimization in Injection Molding Using MPSO-HNN and MPSO Algorithm
(1247 – 1256) Polymer - Plastics Technology and Engineering 49 #12 (2010)
Lee et al used a Hybrid Neural Network trained by Modified Particle Swarm Optimization (MPSO-HNN) to predict warpage based on a Taguchi experiment. All results show that proposed algorithm needs less calculating amounts and spends less time and has better generalization ability than those in related literature. (RDC 11/6/2010)