The recycling process in paper production is complex. Fluctuations in fibre quality and the degree of contamination of the recovered paper bales have a direct influence on production output. At the same time, resource efficiency is more important today than ever before. However, with the current state of the art, it is hardly possible to determine the specific causes of losses and optimise them directly. Yield is usually only measured on a weekly or monthly basis – by the time paper manufacturers receive the information, the losses have already occurred. Furthermore, it is difficult to estimate whether losses in individual stock preparation areas have increased or decreased compared to the last analysis. To address these issues, the Voith has developed OnView.MassBalance.
The digital tool displays losses in stock preparation in real time to further increase the sustainability and efficiency of paper production. At a glance, the operator can locate the specific areas with optimisation potential on the screen. For this purpose, a Sankey diagram maps each feed, accepts and rejects at each process step. As soon as a critical value is reached, OnView.MassBalance reports this to avoid high losses. In this way, standardised processes can be established that can be quickly and easily performed by operators across different shifts. Suitable countermeasures can be, for example, checking the pressure drop or the feed consistency of the last screening stage.
“The solution is already being used successfully, for example in an OCC mill in France with an annual capacity of 250,000 tons,” says Flavio Granito, Global Product Manager Fiber System 4.0, Voith Paper. “After the optimisation phase, 600 tons of rejects, including raw material, could be saved per month. This corresponds to a 2% improvement in yield.”
As there is less rejects to dispose of and at the same time more paper can be produced with the same amount of raw materials, the solution pays for itself in less than a year. Granito explains, “OnView.MassBalance is another example of how digitalization can strengthen more sustainable and cost-efficient papermaking. As part of our major sustainability program ‘Papermaking for Life’, we have set the goal of optimising recycling processes and minimising fibre losses. We aim to achieve a 90% recycling rate by 2030.”
To calculate the mass balance in stock preparation, the tool uses the signals from the sensors installed in the stock preparation plant. Voith experts identify the sensors required for this and develop a suitable concept together with the customer. Voith also separately offers the OnPerformanceLab (OPL) service. Based on bundled know-how, the OPL provides pragmatic support in analysing losses, defining and implementing new countermeasures, and preparing monthly reports in close coordination with the respective paper technologists.
