David O. Kazmer, P.E., Ph.D.
Specializing in plastic product design and polymer process development.

Polymer Process Development

Overview

A fundamental difficulty in injection molding and other dynamic polymer processing operations is the lack of sensing and control of the polymer melt. Due to the presence of an opaque and rigid steel tooling necessary to confine the melt, it is not normally possible to “see” the state of the melt as it is formed during the process. This lack of observability precludes the direct control of the melt flow during polymer processing.

Because of the limited observability, most injection molding processes utilize a hierarchical control architecture in which a process controller provides real time control of critical processing variables and a supervisory controller ensures adherence of the processing variables to the specified processing conditions. Including an outer loop for quality control (often implemented by a human operator), a three level control architecture for polymer processing is established as identified by Wang et. al at Cornell and shown in the figure below (excluding all dashed elements). 

At the innermost level, only the machine elements are regulated to ensure proper execution of the programmed machine inputs. At the second level, state variables such as melt temperature and melt pressure are controlled to track pre-specified profiles. This feedback control will provide more precise control of the state of the melt. While this additional level of control ensures realization of the specified cavity pressure, it still may not lead to a satisfactory molded part because of a poorly specified cavity pressure.  An outer set point control loop is therefore incorporated to adjust the specified cavity pressure.

Past Advances

Tight Tolerance Manufacturing

A quality modeling system has been developed between 1995 and 2005 support manufacturing process development and quality control. The system relies on multiple transfer functions that relate the process variables to the quality attributes. The Extensive Simplex Method is a proprietary algorithm used to derive the set of all feasible process settings based upon the specification limits for the quality attributes. Three different types of feasibility are analytically derived including 1) the global feasible set that establishes the extreme limits of feasibility by allowing all the process variables to vary simultaneously within their allowable range, 2) the local feasibility, which shows the immediate feasibility for each process setting holding other process variables at their current setting, and 3) the controllability that is indicative of the range that may be obtained for each quality attribute while holding other quality attributes at their current value.

The system, shown below, explicitly considers both modeling uncertainty and uncontrolled variation; the specification limits may be automatically tightened by the magnitude of the confidence intervals and variation intervals to ensure feasibility to a desired level of confidence and robustness.  The interface includes 1) the transfer function matrix, 2) tracking of the process settings which may be used in a manner similar to statistical process control charts, 3) tracking of the quality attributes which may be used in a manner similar to statistical quality control charts, 4) the joint feasibility of all pairs of process variables, and 5) the joint feasibility of all pairs of quality attributes (similar to Pareto Optimal graphs). This example is provided for an injection molding process with four process variables and three quality attributes.

This system has been used to establish the feasible bounds of manufacturing processes with tight tolerances. Multivariate modeling and statistical methods are used to predict and optimize the process capability across the global processing domain.

Dynamic Melt Control

Another difficulty in injection molding and other polymer processing operations is the limited controllability of the polymer melt from the plastication unit to one or more locations where the melt is formed. In many injection molds, for example, multiple branches and gates are used in a feed system to deliver the melt to a plurality of locations so as to simultaneously form multiple articles in a single cycle, or alternatively to manufacture larger articles that could not be produced via the distribution of the polymer melt through a single gate. In such conventional feed systems, including both cold and hot runners, the volumetric flow rate and pressure of the polymer melt is determined by the geometry of the feed system. Once specific lengths and diameters are machined, molding machines operating with static feed systems are not able to significantly change the dynamics of the polymer melt at one location without similarly affecting the polymer melt at other locations. As such, the behaviors of the polymer melt at different locations in a mold are coupled, which inherently limits the capability of molding processes. In many cases, a compromise must be made between multiple quality attributes for which significant processing and tooling investments are required for mold optimization. Such issues, occurring late in the product development process, can incur significant cost and time penalties to the manufacturer.

Recognizing the need for improved control of the polymer melt, a self-regulating valve design has been developed as shown below. During operation, polymer melt is delivered to the valve such that the pressure at the valve inlet is greater than the desired pressure at the valve outlet. The valve houses a valve pin designed such that the melt pressure at the outlet of the valve acts on the exposed surface of the valve pin, and generates a force that is proportional to the melt pressure at the valve outlet. The melt pressure force will act to close the valve and thereby reduce the pressure at the valve outlet. A control force is also applied that will act to open the valve and increase the pressure at the valve outlet. If the melt pressure force and the control force are not equal, then the valve pin will tend to move in a direction that corrects the imbalance. For example, if the control force exceeds the pressure force, then the valve pin will move to open the aperture and thereby transmit additional melt pressure to the valve outlet. The valve pin position will be continually and automatically adjusted until force from the melt pressure naturally balances with the control force. As such, the valve is self-regulating; no sensors or external corrective control signal is required to regulate the output melt pressure.

The control force may be applied to the valve pin in a number of ways, including pneumatic actuators, hydraulic actuators, and others. Given that the actuator is matched with a valve, an intensification ratio may be utilized to relate the control signal to the outlet melt pressure. For example, a valve with a 5 mm valve pin diameter may be utilized with a 50 mm pneumatic cylinder diameter. In this case, the pneumatic cylinder has a surface area one hundred times greater than the valve pin. This difference in the “push areas” leads to an intensification ratio similar to the melt pressure exerted by the injection cylinder on a hydraulic molding machine. If a pneumatic supply valve provides 0-1 MPa pneumatic pressure corresponding to a 0 to 10 V control signal, then a 10 V control signal would correspond to a 100 MPa pressure at the valve outlet; other intermediate voltages between 0 and 10 V would proportionally provide between 0 and 100 MPa pressure at the valve outlet. Higher melt pressures, if desired, can be achieved by utilizing a higher pressure hydraulic supply (hydraulic pressure is readily available to 20 MPa) or by utilizing a larger pneumatic cylinder with the same valve pin.

The next figure plots the observed melt pressure in the mold cavity as a function of the observed air pressure in a pneumatic actuator that provides the control force to a self-regulating valve. As indicated by the data points lying near the line of proportionality, the valve provided melt pressure control without melt pressure transducers in proportion to the control force. The small variations from the line of proportionality are due to pressure drops occurring between the outlet of the valve and the location of the pressure transducer in the mold cavity. These results clearly validate the ability of the valve to provide melt pressure control without melt pressure transducers by simply supplying a proportional control force (in this case via a pneumatic pressure acting on a cylinder). It is important to understand the cause of the plateau in the observed melt pressure at approximately 19 MPa. Specifically, the three triangles correspond to molding trials in which high control forces and low melt pressures are supplied. In these cases, the valve opens fully due to the dominating control forces and the low melt pressure is transmitted to the mold cavity through a fully open valve. Self regulation of the melt pressure at these high control forces would be delivered when higher melt pressures are supplied at the valve inlet, as is observed for the molding trials that are represented with the cross symbols.

The integrated system is described in the figure below. A process controller receives an injection forward signal indicating that the screw has started to move and inject material into the mold. Based on user input from the graphical user interface (GUI), the control code operating in the computer send control signals to servo valves that provide regulated pneumatic or hydraulic pressure to the valve actuators. Given the self-regulating nature of the valve, the melt pressure at the outlet will be proportional to the provided control force.  Though not a necessity, it is possible to instrument the molding process with nozzle and cavity pressure transducers to characterize, validate, or debug the process as indicated by the signals with dashed lines.

The capabilities of this system are significant, especially given its low cost. The system allows the processor to change process conditions on a valve by valve basis without modifying mold tooling to significantly and flexibly improve the quality and consistency of manufactured plastic products

Current Research

Extrusion Melt Control

Current process design research is to validate the effectiveness of the self-regulating valve (described above) in extrusion and co-extrusion. If successful, the developed process will outperform other available processes (such as melt pumps) at significantly reduced costs, with immediate application to pipe extrusion, wire coating, profile extrusion, fiber spinning, and many other extrusion processes.

Related Publications

  1. D. O. Kazmer, R. Nageri, V. Kudchakar, B. Fan., R. X. Gao, “Validation of Three On-Line Flow Simulations for Injection Molding,” Submitted to Polymer Engineering and Science.

  2. D. Kazmer , D. Gupta, M. Munavalli, V. Kudchakar, and R. Nageri, “Design and Performance Analysis of a Self-Regulating Melt Pressure Valve,” Accepted to Polymer Engineering and Science.

  3. D. Kazmer, V. Kudchakar, and R. Nageri, “Validation of Molding Consistency with a Self-Regulating Melt Pressure Valve,” Accepted to Journal of Plastics, Rubber, and Composites Processing.

  4. D. Kazmer, V. Kudchakar, and R. Nageri, “Validation of Molding Productivity with Analysis of Two Self-Regulating Melt Pressure Valves,” Accepted to Journal of Plastics, Rubber, and Composites Processing.

  5. D. Kazmer and D. Hatch, “Towards Controllability of Injection Molding,” Journal of Materials Processing and Manufacturing Science, October, 2000, 9 (2), p. 94-99.

  6. Kazmer, D.O. and R.G. Speight, “Polymer Injection Molding Technology for the Next Millenium,” Journal of Injection Molding Technology, 1997. 1(2): p. 81-90.

  7. Kazmer, D., Lotti, C., Breta, R. E. S., Zhu, L., "Tuning and Control of Dimensional Consistency in Molded Products," Advances in Polymer Technology, v. 23, n. 3, Fall, 2004, p. 163-175.

  8. H. Xu and D. Kazmer, “Tight Tolerance Thermoforming,” International Polymer Processing, v. 16, n. 2, p. 208-215, 2001.

  9. J. Reilly, M. Doyle, and D. O. Kazmer, “An Assessment of Dynamic Feed Control in Modular Tooling,” Journal of Injection Molding Technology, September, 2001, 5 (1), p. 52-61.

  10. Xu, H. and D. O. Kazmer, “Productivity Evaluation with a Stiffness-Based Ejection Criterion of Injection Molding,” Journal of Injection Molding Technology, 1999, 3 (4), p. 211-218.

  11. Kazmer, D.O. and C. Roser, “Evaluation of Product and Process Design Robustness,” Research in Engineering Design, 1999. 11 (1), p. 21-30.

  12. Kazmer, D.O., “Best Practices for Injection Molding,” Journal of Injection Molding Technology, 1997. 1(1): p. 10-17.

  13. H. Xu and D. Kazmer, “Thermoforming Shrinkage Prediction,” Journal of Polymer Engineering and Science, v. 41, n. 9, 2001.

  14. S. Johnston and D. Kazmer, “Decoupled Gating and Simulation for Injection Molding,” Submitted to International Polymer Processing.

  15. Kazmer, D., and B. Fan, “Polymer Flow in a Melt Pressure Regulator,” Submitted to the ASME Journal of Manufacturing Science.

  16. B. Fan, D. Kazmer, and R. Nageri, “An Analytical Non-Newtonian and Non-Isothermal Viscous Flow Simulation,” Submitted to Polymer Plastics Technology and Engineering.

  17. Kazmer, D., L. Zhu, and D. Hatch, “Process Window Derivation With an Application to Optical Media Manufacturing,” ASME Journal of Manufacturing Science, v. 123, p. 303-314, 2001.

  18. H. Xu, J. Wysocki, D. Kazmer, P. Bristow, B. Landa, J. Riello, C. Messina, and R. Marrey, “Shrinkage Estimation for Thermoformed Parts,” Thermoforming Quarterly, March, 2000, p. 8-14.

  19. Xu, H. and D. O. Kazmer, “A Stiffness-Based Criterion for Ejection of Injection Molded Parts,” International Journal of Polymer Processing, 1999. 14 (1), p. 52-60.

  20. Petrova, T. and D.O. Kazmer, “Incorporation of Phenomenological Models in a Hybrid Network for Quality Control of Injection Molding,” Polymer-Plastics Technology and Engineering, 1999. 38 (1), p. 1-18.

  21. Petrova, T. and D.O. Kazmer, “Hybrid Neural Networks for Pressure Control of Injection Molding,” Advances in Polymer Technology, 1999. 18 (1), p. 19-31.

  22. S. Dong, C. E, B. Fan, K Danai, and D. O. Kazmer, “Process-Driven Input Profiling for Plastics Processing,” Submitted to the ASME Journal of Manufacturing Science.

  23. D. O. Kazmer and D. Gupta, “A Low Force Melt Valve for Dynamic Control of Molten Plastics,” Submitted to International Polymer Processing.

  24. B. Fan and D. O. Kazmer, “Warpage Prediction of Optical Media,” Journal of Polymer Science: Part B Polymer Physics, v. 41, p. 859-872, 2003.

  25. Yang, D., K. Danai, and D. Kazmer, “A Knowledge-Based Tuning Method for Injection Molding Machines,” ASME J. Manufacturing Science and Engineering, 2001. 123(4): p. 682-691.

  26. Kapoor, D. and D. O. Kazmer, “Consistency and Flexibility of Multi Cavity Melt Control Injection Molding in a Commercial Application,” International Journal of Polymer Processing, 1998. 13 (4), p. 398-405.

  27. Ivester, R., Danai, K. and D. O. Kazmer, “Virtual Search Method for Injection Molding,” Journal of Injection Molding Technology, 1998, 2 (3), p. 165-172.

  28. Kazmer, D.O. and P. Barkan, “Multi-Cavity Pressure Control in the Filling and Packing Stages of the Injection Molding Process,” Polymer Engineering and Science, 1997. 37(11): p. 1865-1879.

  29. Kazmer, D.O. and P. Barkan, “The Process Capability of Multi-Cavity Pressure Control of the Injection Molding Process,” Polymer Engineering and Science, 1997. 37(11): p. 1880-1897.

  30. Kazmer, D.O., J. Rowland, and G. Sherbelis, “The Foundations of Intelligent Process Control,” Journal of Injection Molding Technology, 1997. 1(1): p. 44-56.

  31. Kazmer, D.O., “Injection Molding,” Encyclopedia of Chemical Processing, Marcel Dekker, Sunggyu (K.B.) Lee, Ed., 2005.

  32. Kazmer, D.O., “Precision Process Control,” Precision Injection Molding, Hanser Publishers, R.W. Friedl, J. Greener, Ed., 2005.

  33. Kazmer, D.O. and K. Danai, “Control of Polymer Processing,” in The Control Handbook, edited by W. S. Levine, published by CRC & IEEE Press, 2001.

  34. Kazmer, D.O., “Computer Flow Simulations,” Society of Plastics Engineers’ Molding Toolbox, 2002.

  35. Kazmer, D. O., "Dynamic Feed Control for Injection Molding," Ph.D. Dissertation, Mechanical Engineering Design Division, Stanford University, 1995.

  36. D. Kazmer, “Axiomatic Design Of The Injection Molding Process,” Proceedings of the First International Conference on Axiomatic Design, 2000. Cambridge, MA. 

  37. D. Kazmer, B. Fan, R. Mukhari, "Real Time Flow Rate Estimation in Injection Molding," Molding Technology Symposium at the 20th Annual Meeting of the Polymer Processing Society, Akron, OH, June 21, 2003.

  38. Kazmer, D., B. Fan, and R. Najeri, "On-Line Flow Rate and Pressure Analysis with Sensor Fusion," 2004 Society of Plastics Engineers Annual Technical Conference: Injection Molding Division, Chicago, IL.

  39. Kazmer, D. O., Petrova, T., “Analysis and Synthesis of Methods for Intelligent Processing of Polymeric Materials,” Proceedings of the Polymer Processing Symposium, ASME International Mechanical Exposition, 1997. 

  40. Kazmer, D., K. Manek, et al. (2003), “Prediction of Production Yields in Injection Molding I”, Society of Plastics Engineers Annual Technical Conference: Injection Molding Division, Nashville, TN. 

  41. David O. Kazmer and Mahesh Munavallia, "Design and Performance Analysis Of A Self-Regulating Melt Pressure Valve," Proceedings of the 2005 Society of Plastics Engineers Annual Technical Conference, 2005.

  42. Karania, R., Kazmer, D., and C. Roser, "Plastic Product and Process Design Strategies," ASME DETC 9th Design for Manufacturing Conference, 2004.

  43. Kazmer, D., Manek, K., Lotti, C., Breta, R. E. S., Zhu, L., "Dimensional Tolerancing and Control in Molded Products," Proceedings of the 2003 ASME International Mechanical Engineering Congress & Exposition, Design for Manufacturing Symposium, Washington, D.C., November 16-21, 2003.

  44. D. Kazmer, “The Development of Robust & Confident Decision Spaces,” Proceedings of the 4th National Science Foundation Design & Manufacturing Conference, 2002. San Juan, Puerto Rico. 

  45. Kazmer, D. O.,  Hatch, D., and L. Zhu“An Investigation of Variation and Uncertainty in Six Sigma,” ASME DETC 7th Design for Manufacturing Conference, v 3, p 21-29, 2002. 

  46. Lang, J. and D. Kazmer, “How Increased Control in Plastic Melt Delivery Increases Productivity,” Accepted to Society of Plastics Engineers Annual Technical Conference, May 2002. 

  47. Doughty, M., Kazmer, D., “Dynamic Feed – Precision Molding in a Family Tool Application,” Plastics Odyssey 2001, Rochester, NY, Sept. 24-25, 2001.

  48. Hawk, L, Kazmer, D., “Commercial Applications for Dynamic Feed™ Providing Dimensional Control for Each Injection Cavity,” K-Plast Processing Innovations, Düsseldorf/Neuss, Germany, 2001. 

  49. Xu, H. and D. O. Kazmer, “Validation of a Stiffness-Based Ejection Criterion for Injection Molding.” in Proceeding of the Society of Plastics Engineers Annual Technical Conference, 1999. New York, NY. 

  50. David O. Kazmer, Ranjan Nageri, Bingfeng Fan, Vijay Kudchadkar, Stephen Johnston, "Validation of On-Line Molding Process Simulation," Proceedings of the 2005 Society of Plastics Engineers Annual Technical Conference, 2005.

  51. David O. Kazmer, Kathryn Garnavish, & Ranjan Nageri, "An Investigation into Hesitation Effects in Oscillating Flows," Proceedings of the 2005 Society of Plastics Engineers Annual Technical Conference, 2005.

  52. D. Kazmer, and B. Fan, "Simulation of Polymer Flow in a Dynamic Pressure Regulator," 8th International Conference on Numerical Methods in Manufacturing Processes, American Institute of Physics, June, 2004.

  53. Ambady, P. and D. O. Kazmer, “Model Predictive Control of Injection Molding,” Society of Plastics Engineers Annual Technical Conference, May 2001. Dallas, TX. 

  54. Bernier, M. Doyle, D. Kazmer, and T. Powell, “Shear Rates in Dynamic Feed,” Proceeding of the Plastics Odyssey, SPE Regional Technical Conference, 2001, Rochester, NY. 

  55. P. Ambady, B. Fan, D. Hatch, and D. Kazmer, “Process Design For Optimal Mold Cooling,” Proceedings of Materials Processing Symposium of the ASME International Mechanical Engineering Congress & Exposition, 2000. 

  56. Petrova, T., Kazmer, D. O., “Development of a Hybrid Neural Network for Quality Control of Injection Molding,” in Proceeding of the Society of Plastics Engineers Annual Technical Conference, 1998. Atlanta, GA. 

  57. Kazmer, D. O., Rowland, J. R., “The Challenges of Intelligent Process Control”, Proceedings of the International Polymer Processing Symposium, 1997.

  58. David O. Kazmer, Vijay Kudchadkar, and Ranjan Nageri, "Performance of a Self-Regulating Melt Pressure Valve," Proceedings of the 2005 Society of Plastics Engineers Annual Technical Conference, 2005.

  59. David O. Kazmer and Hitesh Mundhra, "Derivation of Process Windows," Proceedings of the 2005 Society of Plastics Engineers Annual Technical Conference, 2005.

  60. D. Kazmer, L. Zhu, "Self-Regulating Melt Brakes for Dynamic Control of Molten Plastics," National Science Foundation Design & Manufacturing Conference, Scottsdale, AZ, 2005.

  61. Kazmer, D., Gupta, D., and B. Fan, "Design and Validation of a Self-Compensating Melt Regulator for Plastics Extrusion," 2004 Society of Plastics Engineers Annual Technical Conference: Extrusion Division, Chicago, IL.

  62. D. Kazmer, “Synthesis of Melt Pumps and Brakes for Polymer Processing,” National Science Foundation Design & Manufacturing Conference, 2004.

  63. R. Abbott, R. Combs, D. Kazmer, G. Magnant, S. Winebaum, “Elimination of Process Constraints in Plastics Injection Molding”, Molding 2003 Executive Technology Conference, New Orleans, LA, 2003.

  64. Balasubrahmanyan, G. and D. Kazmer (2003). “Thermal Control of Melt Flow in Cylindrical Geometries,” Society of Plastics Engineers Annual Technical Conference: Injection Molding Division, Nashville, TN.

  65. Wang. F., Dong, S., Danai, K. D., and D. O. Kazmer, “Input Profiling for Injection Molding by Reinforcement Learning,” Society of Mechanical Engineers, Dynamic Systems and Control Division, v 70, 2002, p 701-708. 

  66. Wang. F., Dong, S., Danai, K. D., and D. O. Kazmer, “Input Profiling for Injection Molding by Reinforcement Learning,” Joint USA/Japan Symposium on Manufacturing, June 2001. 

  67. Hatch, D., D. O. Kazmer, and B. Fan, “Dynamic Cooling Design for Injection Molding,” Society of Plastics Engineers Annual Technical Conference, May 2001. Dallas, TX. 

  68. Reilly, J., Doyle, M., and D. O. Kazmer, “An Assessment of Dynamic Feed Control in Modular Tooling,” Society of Plastics Engineers Annual Technical Conference, May 2001. Dallas, TX. 

  69. K. Johnson, D. O. Kazmer, “Innovative Feed System Technology for Global Competitiveness,” PlasticsUSA, 2001. Chicago, IL.

  70. Danai, K., and D. O. Kazmer, “Knowledge-Based Interval Modeling Method for Tuning Injection Molding Machines,” Proceedings of the 3rd National Science Foundation Design & Manufacturing Conference, 2001. 

  71. D. O. Kazmer, “Dynamic Cooling For Injection Molding,” Office of Naval Research Progress Reports, 2000.

  72. Danai, K., and D. O. Kazmer, "Method of Tuning and Automatic Regulation for Injection Molding," Proceedings of the 2nd National Science Foundation Design & Manufacturing Conference, 2000. Monterrey, Mexico. 

  73. K. Danai and D. O. Kazmer, “Knowledge Based Interval Modeling Method for Tuning Injection Molding Machines,” Proceedings of the 3rd National Science Foundation Design & Manufacturing Conference, 2000. Tampa, FL. 

  74. D. Yang, K. Danai, and D. Kazmer, “A Knowledge Based Tuning Method for Injection Molding,” Proceedings of Controls Division of the ASME International Mechanical Engineering Congress & Exposition, 2000.

  75. Yang, D. Kazmer, and K. Danai, “A Knowledge Based Tuning Method,” Proceedings of the Annual Technical Meeting of the Society of Plastics Engineers, Orlando, FL, 2000. 

  76. Kazmer, D. and D. Hatch. “Towards Controllability of Injection Molding.” Proceedings of the Polymer Processing Symposium, ASME International Mechanical Exposition, 1999. 

  77. Yang, K. Danai, and D. Kazmer, “A Knowledge Based Tuning Method for Injection Molding Machines,” Proceedings of the USA-Japan Symposium on Manufacturing Technologies, 2000.

  78. Doyle, M., A. Bernier, K. Camille, and D. O. Kazmer,, “Utilization of Dynamic Feed Control in Family Tools .” in Proceeding of the Society of Plastics Engineers Annual Technical Conference, 1999. New York, NY. 

  79. Yang, H., Danai, K., Hatch, D. and D. O. Kazmer, “Yield Maximization In Injection Molding by the Virtual Search Method.” in Proceeding of the Society of Plastics Engineers Annual Technical Conference, 1999. New York, NY. 

  80. Cahill, B., Doyle, M., Kazmer, D., Moss, M., Niemeyer, M., “Utilization of Dynamic Feed Control for Commercial Applications,” in Proceeding of the Society of Plastics Engineers Annual Technical Conference, 1998. Atlanta, GA. 

  81. Kapoor, D., Kazmer, D. O., “Consistency of Multi Cavity Melt Control Injection Molding in a Commercial Application,” in Proceeding of the Society of Plastics Engineers Annual Technical Conference, 1998. Atlanta, GA. 

  82. Ivester, R., Danai, K., Kazmer, D., “Automatic Tuning of Injection Molding by the Virtual Search Method,” in Proceeding of the Society of Plastics Engineers Annual Technical Conference, 1998. Atlanta, GA. 

  83. Kazmer, D. O., Danai, K., “Automatic Tuning and Regulation of Injection Molding,” NSF Division of Design, Manufacturing, and Industrial Innovation, Grantees Conference, Monterrey Mexico, January 1998. 

  84. Kapoor, D., Kazmer, D. O., “The Definition and Use of the Process Flexibility Index,” Proceedings of the 1997 ASME Design for Manufacturing Conference. 

  85. Kapoor, D., Kazmer, D. O., “Multi-Cavity Melt Control for Injection Molding”, Proceedings of the ASME International Mechanical Exposition, 1997.

  86. Rowland, J. R., Kazmer, D. O., “Quantifying the Economic Value Added of On-Line Quality Control Systems”, in Proceeding of the Society of Plastics Engineers Annual Technical Conference, 1997. 

  87. Sherbelis, J. R., Garvey, E., and Kazmer, D. O., “Methods and Benefits of Establishing a Process Window,” in Proceeding of the Society of Plastics Engineers Annual Technical Conference, 1997. 

  88. Kazmer, D., Thomas, R., and G. Sherbelis, "Quality Regulation Techniques for Injection Molding," Proceedings of Polymer Process Engineering, 1997. 

  89. Thomas, R., Rowland, J., Kazmer, D., “On-Line Injection Control Systems Ace the Value Test,” Modern Plastics, November 1997, p. 83-86. 

  90. Garvey, E. G., Kazmer, D. O., “Application of Matlab® to Injection Molding Quality Control,” Proceedings of the 3rd Annual Matlab Users Conference, Melbourne, Australia,1996. 

  91. Kazmer, D. O., “An On-line Quality Monitoring System for Thermoplastic Injection Molding,” Proceedings from the 1996 AIChE Conference. 

  92. Rowland, J. C., Kazmer, D. O., “An On-line Quality Monitoring System for Thermoplastic Injection Molding,” in Proceeding of the Society of Plastics Engineers Annual Technical Conference, 1996. 

  93. Kazmer, D. O., “Introduction to Dynamic Feed Control,” in Proceeding of the Society of Plastics Engineers Annual Technical Conference, 1994.

  94. Kazmer, D. O., “CAE & Polymer Processing Monitoring & Control: A Design Perspective,” 2001 Gordon Conference on CAE in Polymer Processing, March 2001. Ventura, CA. 

  95. D. Kazmer, “Fundamentals of Polymer Processing,” Proceedings of the Annual Technical Meeting of the Society of Plastics Engineers, Orlando, FL, 2000. 

  96. D. Kazmer, “Advanced Methods for Plastic Product Design and Process Control,” Toyota Motor and Suppliers Meeting, Lowell, MA, April 22, 2005.

  97. Kazmer, D. O., “Synthesis and Analysis of Quality Control Methods for Intelligent Processing of Polymeric Materials,” Canada National Research Center, Montreal, Quebec, February 2000. 

  98. Kazmer, D. O., Rowland, J. R., “The Challenges of Intelligent Process Control”, Proceedings of the International Polymer Processing Exposition, 1997.

  99. D. Kazmer, “Self-Regulating Melt Valves for Polymer Processing,” SPE Merrimack Valley Meeting, National Plastics Center, May 12th, 2005.

  100. D. Kazmer, “Self-Regulating Melt Valves for Polymer Processing,” Synventive Molding Solutions Meeting, Lowell, MA, May 10th, 2005.

  101. Kazmer, D., “The Economics of Lights Out Manufacturing,” Society of Plastics Engineers Topical Conference on Injection Molding Systems, Cleveland, OH, October, 2004. 

  102. Kazmer, D., “Advanced Process Control Techniques,” PlasticsUSA Molding Technology 2001, Chicago, IL, 2001. 

  103. D. Kazmer, K. Danai, "Virtual Search Method for Injection Molding," GE Plastics, 2000. 

  104. Kazmer, D. O., “Manufacturing Process Design: Towards Controllability of Injection Molding,” Lehigh University Mechanical Engineering Departmental Seminar, November 1999.

  105. Kazmer, D. O., “Manufacturing Process Design,” Massachusetts Institute of Technology Design Research Seminar, 1998.

  106. Kazmer, D. O, "Dynamic Feed Control: Technology for Injection Molding Flexibility & Capability," GE Plastics, 1997. 

  107. Kazmer, D. O., “Dynamic Feed Control,” GE Plastics Polymer Processing Development Center, 1995.

  108. D. Kazmer, Technical Report to MoldMasters Ltd., “Technical Feasibility of Advanced Molding Technnologies: On-Line Flow Simulation, Digital Valve Modulation, and Self Regulating Valves,” 490 pages, 2004.

  109. Kazmer, D., Hatch, D., Zhu, L., "Four Measures of System Performance," 2002. 

  110. D. Kazmer, Invention Disclosure, Looking Glass: An Optimization System for Injection Molding, 1998.

  111. D. Kazmer, Invention Disclosure, Self-Regulating Pressure valve for Polymer Processing, 2004.

  112. D. Kazmer, Melt Control System for Injection Molding, U.S. Patent Application Number 2004/0119182, June 24, 2004.

  113. D. Kazmer, Invention Disclosure, A Melt Control System for Injection Molding Using a Spool Valve, 2003.

  114. Kazmer, D. O., "Dynamic Cooling for Injection Molding," Final Report to Office of Naval Research, 2003. 

  115. D. Kazmer, Invention Disclosure, Radial Valve Gating for Dynamic Melt Control, 2002.

  116. D. Kazmer, Invention Disclosure, Method of Process Simulation with a Mold Assembly, 2002.

  117. D. Kazmer, Invention Disclosure, Method For Pumping and Braking the Flow of Polymer Melt, 2002.

  118. Doughty, M. A., Firisin, W. D., Hume, W. J., Moss, M. D., Kazmer, D. O., "Controlled injection using manifold having multiple feed channels," U.S. Patent No. 6,767,486, July 27, 2004. 

  119.  Kazmer; D. O., Moss, M., Doyle, M.; van Geel, H., "Manifold system having flow control," U.S. Patent No. 6,713,002, March 30, 2004. 

  120. Moss, M., Kazmer, D. O., “Apparatus and method for proportionally controlling fluid delivery to readily replaceable mold inserts,” U.S. Patent No. 6,638,049, October 28, 2003. 

  121. Kazmer, D. O., Moss, M., Doyle, M., “Dynamic feed control system,” U.S. Patent # 6,632,079, October 14, 2003. 

  122. Doughty, M. A., Firisin, W. D., Hume, W. J., Moss, M. D., Kazmer, D. O., “Controlled injection using manifold having multiple feed channels,” U.S. Patent # 6,589,039, July 8, 2003.

  123. Kazmer, D. O., Moss, M., “Machine for proportionally controlling fluid delivery to a mold,” U.S. Patent # 6,585,505, July 1, 2003. 

  124. Kazmer, D. O., Moss, M., Bassett, B., Doyle, M., “Apparatus and method for purging injection molding system,” U.S. Patent # 6,514,440, February 4, 2003. 

  125. Kazmer, D. O., Moss, M., Doyle, M., van Gee, H. “Manifold system having flow control,” U.S. Patent # 6,464,909, October 15, 2002. 

  126. Kazmer, D., Moss, M., “Method using manifold system having flow control,” U.S. Patent # 6,436,320, August 20, 2002. 

  127. Kazmer, D., Moss, M., “Manifold system having flow control using pressure transducers,” U.S. Patent # 6,361,300, March 26, 2002. 

  128. Fuller, N., Moss, M., Kazmer, D. O., Galati, V., "Apparatus and Method for Proportionally Controlling Fluid Delivery to Stacked Molds," International Application No. WO 02/074516, March 19, 2002.

  129. Kazmer, D., Moss, M., “Manifold system having flow control using separate cavities,” U.S. Patent # 6,343,921, February 5, 2002. 

  130. Kazmer, D., Moss, M., “Manifold system having flow control using pressure transducers,” U.S. Patent # 6,343,922, February 5, 2002. 

  131. K. Danai and D. Kazmer, Invention Disclosure, Virtual Search Method for Injection Molding, 2001.

  132. D. Kazmer, Invention Disclosure, Dynamic Cooling for Injection Molding of Thermoplastic Parts, 2000.

  133. Kazmer, D. O., Moss, M. D., Doyle, M, "Dynamic Feed Control System," International Application No. WO 01/60580, February 13, 2001.

  134. Kazmer, D., Moss, M., “Manifold system having flow control using extended valve pin,” U.S. Patent # 6,254,377, July 3, 2001. 

  135. Kazmer, D., Moss, M., “Apparatus for proportionally controlling fluid delivery to a mold,” U.S. Patent #6,287,107 , September 11, 2001. 

  136. Kazmer, D., Moss., M., “Electric actuator for a melt flow control pin,” U.S. Patent #6,294,122, September 25, 2001. 

  137. Doughty, M. A., Firisin, W. D., Hume, W. J., Moss, M. D., Kazmer, D. O., "Controlled injection using manifold having multiple feed channels," International Application No. WO 02/36324, October 29, 2001.

  138. Kazmer, D., Moss, M., “Apparatus for proportionally controlling fluid delivery to a mold,” U.S. Patent #6,309,208, October 30, 2001. 

  139. Kazmer, D. O., Moss, M. D., "Apparatus and Method for Proportionally Controlling Fluid Delivery to a Mold," International Application No. WO 01/34362, November 3, 2000.

  140. Kazmer, D. O., Moss, M. D., "Manifold System Having Proportional Flow Control," International Application No. WO 01/34364, November 3, 2000.

  141. Kazmer, D. O., Moos, M. D., Doyle, M., VanGeel, H., "Manifold System Having Flow Control," International Application No. WO 01/21377, September 21, 2000.

  142. Kazmer, D. O., Moss, M., "Manifold System Having Flow Control," International Application No. WO 99/54109, May 27, 1998.

  143. Kapoor, D., and D. Kazmer, "Comparison of Sequential Valve Gate Molding to Multi-Cavity Melt Control Injection Molding," 1998. 

  144. D. Kazmer, Invention Disclosure, Twin Screw Extruder for Continuous Manufacture of Concrete, 1997.

  145. Kazmer, D. O., “Injection molding gate flow control,” U.S. Patent #5,556,582, September 17, 1996.