Abstract
Polymer injection-molding is one of the most used manufacturing processes for the production of plastic products. Its electricity consumption highly influences its cost as well as its environmental impact. Reducing these factors is one of the challenges that material science and production engineering face today. However, there is currently a lack of data regarding electricity consumption values for injection-molding, which leads to significant errors due to the inherent high variability of injection-molding and its configurations. In this paper, an empirical model is proposed to better estimate the electricity consumption and the environmental impact of the injection-molding process. This empirical model was created after measuring the electricity consumption of a wide range of parts. It provides a method to estimate both electricity consumption and environmental impact, taking into account characteristics of both the molded parts and the molding machine. A case study of an induction cooktop housing is presented, showing adequate accuracy of the empirical model and the importance of proper machine selection to reduce cost, electricity consumption, and environmental impact.
Highlights
Climate change is forcing companies to perform risk management as well as look for opportunities to reduce the environmental impact of their operations [1,2].The concern regarding the achievement of sustainable development is patent in the literature.Strategies to achieve a cleaner industrial sector have been discussed using, for example, analytical tools that help in the decision-making of an industrial process [3] or linking lean manufacturing practices with the lifecycle assessment methodology in order to reduce the environmental impact [4].Polymer injection-molding is a standard manufacturing process that is typically characterized by high production volumes [5]
An empirical model was proposed to achieve better estimations of the electricity consumption of the injection-molding process. Databases such as EcoInvent provide an average electricity consumption value (1.47 kWh/kg) for the injection-molding process; considering this value as a constant for every injected molded part leads to significant errors as the variability in these processes is very high
Our empirical model obtained an average SEC absolute error of 22.5%, which was much lower than the 86.8% obtained when using EcoInvent data
Summary
Climate change is forcing companies to perform risk management as well as look for opportunities to reduce the environmental impact of their operations [1,2].The concern regarding the achievement of sustainable development is patent in the literature.Strategies to achieve a cleaner industrial sector have been discussed using, for example, analytical tools that help in the decision-making of an industrial process [3] or linking lean manufacturing practices with the lifecycle assessment methodology in order to reduce the environmental impact [4].Polymer injection-molding is a standard manufacturing process that is typically characterized by high production volumes [5]. Strategies to achieve a cleaner industrial sector have been discussed using, for example, analytical tools that help in the decision-making of an industrial process [3] or linking lean manufacturing practices with the lifecycle assessment methodology in order to reduce the environmental impact [4]. Electricity is required during several steps of this process, from the movements of the machine that allow the closure of the mold, filling the cavity, holding and ejecting of the part, to the plasticizing phase of the polymer and the needs of cooling for both the machine and its parts. In order to carry out these steps of the cycle, injection-molding machines are composed of two different units: the injection unit and the clamping unit. The injection unit is responsible for heating the polymer up to the injection temperature by rotating the screw and using electric resistors
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call