The task of a system for handling graphic recovered paper is to efficiently process the delivered bales, remove wire and prepare them for the deinking process. Voith offers a wide range of solutions for this first step in the DIP process – optimally tailored to different waste paper qualities and plant concepts.

The main task of the Protector System for cleaning at high stock consistencies (HC Cleaner) is the early separation of abrasive contaminants. Efficient separation extends the service life of all downstream machines and pumps. Voith uses a two-stage system here to achieve the best possible results.

In the cleaning system for low stock consistencies (LC Cleaner), the remaining heavy particles, especially sand, are removed from the fiber suspension by centrifugal separation. Compared to other manufacturers, the Voith system scores with better separation at higher stock consistencies. This is made possible by the EcoMizer technology developed by Voith.

Screening is used in various stages of the paper making process to reliably remove unwanted substances from the fiber suspension.

Coarse screening (DIP):
Coarse screening efficiently removes plastics, polystyrene, and other coarse particles from the fiber suspension. The Voith system relies on a closed, multi-stage concept without additional intermediate chests, which minimizes installation costs, energy consumption, and the risk of clogging.

Fine screening (DIP):
In fine screening, remaining specks, small disruptive reject particles, and stickies are selectively removed. Screening efficiency is ensured by precisely coordinated circuit variants and narrow slot widths. The Voith screening system is individually adapted to the respective DIP line and the desired end product.

The main objective of deinking flotation is to selectively remove disturbing printing inks, stickies, and other hydrophobic particles from the fiber suspension. This increases the brightness and improves the optical cleanliness of the final product. Fillers and coating particles can also be effectively eliminated.

Thanks to the selective flotation process, valuable fibers remain in the accepted stock, while unwanted particles are efficiently removed. It is crucial that the hydrophobic particles detach from the fibers – only then can they be picked up by the air bubbles and removed. The result: minimal fiber loss and consistently high paper quality.

The thickening stage in the DIP process increases the stock density and reduces the storage volume of the fiber suspension. At the same time, it provides clean filtrate that can be efficiently reused in the plant's water cycles. Our thickeners and dewatering machines are characterized by high mechanical robustness and durable filter elements.

By increasing the stock consistency – typically from around 5% to up to 30% – the subsequent dispersion is optimally prepared and a clear separation of the water circuits is achieved. Continuous and uniform discharge ensures a stable, homogeneous supply to the next process steps, reduces energy peaks, and lowers overall energy requirements. This ensures reliable and economical operation of the DIP line.

The dispersion system homogenizes the dewatered stock and breaks down dirt specks and stickies below the visible range. This extremely compact dispersion system requires only three machines – the screw press, the high-speed heating system and the disperser. Coming from the screw press, the dewatered stock is then processed and heated with steam in the rapid heating system. If needed, it can also be used to mix in bleaching chemicals. Voith dispersers achieve the best optical paper properties with minimal energy consumption.

The efficient treatment of rejects, process and wastewater, as well as the sludge generated during flotation and DAF, is a central component of every modern DIP line. Impurities and rejects must be reliably removed from the system, dewatered and, depending on the concept, further treated or disposed of. Targeted sludge treatment, especially of flotation and DAF sludge, also contributes significantly to process reliability and compliance with environmental standards.

Well-designed reject and sludge management prevents disruptions or downtime in stock preparation and ensures stable operation. At the same time, water management is essential: even the smallest impurities can accumulate in the circuit and impair plant performance. Wastewater treatment also poses special challenges for paper mills, such as deposits or strict environmental regulations. Voith offers tailored solutions – from efficient fiber and water recovery to advanced sludge treatment and cleaning systems to anaerobic reactors for reducing energy consumption. This ensures sustainable, economical, and safe operation of the DIP line in the long term.

Plant-wide optimized water management, coordinated tank volumes, and integrated control enable optimal specific fresh water consumption under all production conditions.