Global plastic production has been increasing for 75 years at an average growth rate of 8 %. A large part of subsequent processing uses injection molding, enabling mass production of a wide range of components for industries like automotive or packaging. Due to its widespread use and high energy consumption, considerable potentials for energy savings exist, contributing to more sustainable plastics processing. Therefore, a holistic energy measurement concept and framework was developed including not only the injection molding machine’s energy consumption (drive and cylinder heaters), but also required peripherals (temperature control units etc.) and machine cooling, covering all available energy and heat flows in the injection molding process. Since energy efficiency measures in injection molding are usually associated with quality decline, extensive material testing was conducted on manufactured tension rods alongside energy optimization. Using DoE, ANOVA and RSM purely process parameter-based reductions in specific energy consumption of up to 18 % were achieved for materials PP, PP-GF30, ABS and PPS on a fully electric Arburg 470 A without disadvantages in mechanical, geometric, and optical properties. The cycle time had the greatest influence on specific energy consumption. At the same time, other injection molding parameters also offer significant optimization potential. The determined performance and energy data were also used in an algorithm-based cycle detection system, enabling injection molding process quality monitoring based on performance characteristics and identifying dominant energy consumers. Furthermore, determined energy values can be transferred to sustainability software like LCA for Experts. Besides average injection molding data available in the database, material-specific datasets like these enable more accurate representation of environmental impacts. Download: Download Word document (29KB)
Kerkenberg et al. (Thu,) studied this question.