Plastics Technology

OCT 2018

Plastics Technology - Dedicated to improving Plastics Processing.

Issue link:

Contents of this Issue


Page 21 of 75

Another existing package is HiQ Flow, which measures material viscosity by means of the work during injection. It adjusts the high-pressure level or switchover point, or both, during the shot to make a same-cycle correction. While the software currently requires a few shots to determine the viscosity correction factor by trial and error, Wittmann Battenfeld is developing an enhancement to automatically define the correction factor. A new addition to the series is HiQ Metering, which achieves positive closing of the check valve by means of a specific screw movement prior to injection. This serves to ensure uniform shot size. AUTONOMOUS INJECTION MOLDING The potential for an injection machine to perform its own real-time quality assessment and correct its process without human intervention or post-molding QC tests was presented by Dr. Gerald R. Berger, Asst. Prof. of plastics injection molding at the Institute of Injection Molding of Polymers at the University of Leoben, Austria; and by Dr. Dieter P. Gruber, head of the Research Group on Robot Vision and Artificial Intelligence at Polymer Competence Center Leoben in the same city. The two of them had just begun a three-year research project on "Inline Quality Control in Injection Molding" (InQCIM), funded by 1 million euros con- tributed by the Austrian government and industry partners such as Wittmann Battenfeld, which is also donating an all-electric EcoPower 110 machine to the project. Other partners in this project include the Research Institute of Production Technology and High-Power Laser Technology (IFT) at the Vienna University of Technology (TU Wien), as well as German and Austrian automotive suppliers like Mahle Filtersysteme, Austrian furniture hardware producer Julius Blum, and Austrian custom/captive molder Miraplast. The goal of autonomous injection molding, say Berger and Gruber, is to replicate on each shot the pressure, temperature and velocity conditions of the melt relative to time and position in the molding cycle. This is to be done by continuously monitoring melt pressure, temperature, and velocity in the cavity as well as the mold wall temperature. The fundamental concept of the autonomous molding project is to make an "intelligent mold" the master of the process through bidirectional communications with the injection press and peripheral equipment. In other words, the instrumented mold tells the injection machine what process corrections to make. One aim of the project is to address surface quality of molded parts—sinks, weld lines and flow marks ("tiger stripes")—and correlate these factors with mold-sensor data. Initial work will use a camera to inspect parts, but the eventual goal is to be able to predict visual defects from mold data. One of the innovations being explored by the project team is monitoring the mold only with an array of acoustical sensors on the outside of the mold. This is a less costly and more robust solution than in-mold sensors, according to Berger and Gruber. The initial goal is to be able to correct the process in the next two cycles after a problem is detected. Farther down the road, the researchers hope to correct the process within the same cycle and even to look ahead four or five cycles to predict an impending error, based on current trends, and react before a quality issue arises. To make this happen, the researchers need to develop a machine-learning-based Fault Detection and Classification (FDC) software system. This will involve training neural- network software to recognize when and how to adjust the process. The first step in the research project will be Design of Experiments (DOE) testing to correlate part weight, dimensions, surface quality, and mechanical performance with mold-sensor data. Research project launched to develop a self- learning machine and smart mold that can perform in-mold QC and correct the process accordingly. Reduce scrap and improve quality with Per-Fix ® specialty flaw repair coatings. Salvage costly parts with surface imperfections with our permanent flaw repair touch-up coatings. In 60-seconds, Per-Fix instantly repairs the most common visual part defects including knit/flow lines, gloss imperfections, splay and many others. 800-336-9828 • SPRAY-ON PERFECTION Per-Fix ® Clear Transparent coating to fix light to medium flaws. Free evaluation kit. Per-Fix ® Black For deeper flaw repairs. Free evaluation kit. Per-Fix ® Color Match Custom formulated based on full-color analysis of existing products. Free sample match. 20 OCTOBER 2018 Plastics Technology I N J E C T I O N M O L D I N G Close -Up On Technolog y

Articles in this issue

Links on this page

Archives of this issue

view archives of Plastics Technology - OCT 2018