When water determines coating quality

The existing water-treatment system at the Cologne-Porz site had operated reliably for many years and was continuously developed by EnviroFALK. As requirements increased, however, so did the need for greater transparency and targeted process control.

The objective was a modern solution in line with Industrie 4.0, offering end-to-end process and data transparency as well as the ability to monitor and control every system stage in real time.

Together with EnviroFALK, a purified-water recirculation system was developed specifically to meet these requirements. Today, all relevant process stages are centrally monitored and visualised in real time. 

Purified water is produced through a clearly structured, multi-stage process within a closed-loop system. The aim is to deliver consistently high, reproducible water quality that meets the requirements of the coating processes.

In this case, the first step is to filter the well water in order to reliably remove particulate contaminants. Further treatment then takes place across several coordinated process stages: softening reduces hardness-forming substances and protects downstream system components, while reverse osmosis (RO) performs the main desalination step. Subsequent electrodeionisation (EDI) provides polishing demineralisation, resulting in very low conductivity levels. Downstream storage in sloping tanks with UV disinfection ensures the microbiological stability of the purified water.

The purified water produced in this way is used specifically in the production process and supplied to the washing machine. During cleaning, it ensures thorough removal of contaminants from the glass surfaces, creating the essential prerequisite for a uniform, high-quality coating. At this stage of the process, water quality has a direct impact on product quality and the reject rate.

A key feature of the system concept is the consistent recirculation of process water. The wash water produced is not discarded, but undergoes multi-stage reprocessing before being returned to the process. Ultrafiltration first reliably removes particles, colloids and microbiological constituents. A two-stage reverse-osmosis process then reduces dissolved substances. The pretreated water subsequently passes through the central stages of the water-treatment system again before being returned to the washing process.  

The targeted combination and coordination of the individual process steps creates a closed system with transparent controls. It not only guarantees stable, reproducible water quality, but also enables the transition from a linear consumption model to resource-efficient recirculation. In addition to process reliability, the concept therefore makes a significant contribution to reducing fresh-water demand and wastewater volumes, while meeting growing requirements for sustainability and cost-effectiveness in industrial production.

Particular emphasis is also placed on measurement and control technology with IOLink. It enables continuous communication down to sensor level and provides advanced diagnostic and process data in real time. The objective was to create maximum transparency while ensuring stable system operation. All relevant process data is available in real time via a central dashboard. Deviations can be detected early and corrected in a targeted manner. 

Not only the technical solution, but also implementation while production continued presented the project with particular challenges. Installation and commissioning had to take place within a tight time frame, placing correspondingly high demands on planning and coordination.

Through close cooperation between the EnviroFALK and Saint-Gobain Glass Germany project teams, all interfaces were defined at an early stage and precisely coordinated. This aligned approach laid the foundation for a smooth process and the successful commissioning of the purified-water recirculation system shortly before the end of the year.

The combination of recirculation, precise control technology and continuous monitoring enables stable water quality during ongoing operation. This has a direct impact on process reliability and coating quality. At the same time, resources are used more efficiently: water consumption falls, process deviations are reduced and system operation can be optimised in a targeted manner.

As requirements for energy efficiency, product quality and sustainability increase, water treatment is becoming an increasingly important focus in industrial processes. In sensitive applications such as glass coating in particular, it is becoming an integral part of the production strategy. 

The example at the Cologne-Porz site shows how modern purified-water recirculation systems help create transparency, conserve resources and ensure stable process conditions at the same time.

In glass coating, water is far more than an auxiliary medium. It is a decisive process parameter. Consistently high water quality is the prerequisite for stable processes, reproducible results and economical production. Coating quality therefore begins with water treatment.