Energy-efficient automation of industrial surface pre-treatment processes using PLC and SCADA

Manual and semi-automatic pre-treatment processes in industrial manufacturing are often criticized for operational inconsistencies, excessive energy consumption, and safety risks associated with human exposure to hazardous substances. These limitations adversely affect overall production efficiency and hinder competitiveness in the era of modern manufacturing. To address these challenges and achieve an energy-efficient and reliable automation solution, this paper proposes a programmable logic controller (PLC) and supervisory control and data acquisition (SCADA) based automation framework for an industrial nine-tank surface pre-treatment line. The proposed system integrates temperature, pH, and level sensors with actuators, enabling closed-loop conveyor control for fully automated operation through precise event sequencing and interlocking mechanisms. Furthermore, real-time monitoring, alarm management, and data logging implemented through the SCADA-based human–machine interface (HMI) significantly enhances operational efficiency, process reliability, and worker safety. Compared to conventional plant operation, the PLC–SCADA integrated system demonstrates substantial performance improvements by reducing the processing cycle duration from 90–60 minutes to 45–50 minutes, and increasing monthly production from 200 to 250 batches. Additionally, optimized control actions supported by real-time monitoring achieve a 16% reduction in monthly energy consumption. The results highlight the effectiveness of PLC–SCADA-based automation as a cost-effective and energy-efficient solution, underscoring its potential to support sustainable Industry 4.0-oriented manufacturing systems.