Five problems and five solutions for paper mills

We produce spray nozzles, atomizers, tank washing nozzles, and shower pipes for the paper industry, helping to prevent and solve many recurring problems.

Five problems and five solutions for paper mills

We produce spray nozzles, atomizers, tank washing nozzles, and shower pipes for the paper industry, helping to prevent and solve many recurring problems.

The problems found in paper mills are various. We analyzed five of them to suggest five solutions with PNR Italia products.

In the paper industry, water is one of the main components: in the initial stages of production, the solution consists of 95-97% water and 3-5% pulp and fiber. It is, therefore, expected that a company like PNR Italia, which has produced nozzles, atomizers, tank washing devices, and shower pipes for over fifty years, has specialized in this field with products designed ad hoc.

The spray nozzles, shower pipes, atomizers, and tank washing nozzles produced by PNR Italia play a crucial role in all phases of paper production. Applications of spray nozzles and other products are many: starch treatment, cleaning of felt and forming cloths, washing, foam abatement in the inflow crates, and refilling of paper, to name a few.

But what are the most common issues in paper mills and how can PNR Italia products be useful? Let’s see them together.




Generation of froth in the preparation of dough

The first process is to insert the dough into the pulper: this operation recovers the cellulose fibers that are well separated and hydrated to form the actual dough.
Surfactants and all the substances suspended in the water during this process generate froth that we have to break down before overflowing from the tank.
Froth is knocked down with jets of water. The ideal product for this operation is the full cone nozzle of the D series of PNR Italia.




Clogging in starch spraying

The starch spraying phase takes place in the suction box area. The purpose of spraying starch is to compact the fibers of the dough to make the final product more durable.
The sprayed substance, generally called starch, is composed of corn, potatoes, wheat flour, and other chemical components. Since starch is a highly viscous solution, clogging the spraying devices is possible.
PNR Italia offers its P series hollow cone nozzles to minimize this possibility.




Smudges in the paper refill

After the dough has been distributed on the forming canvas, its proceeds so that as much water is taken from it as possible. Among the various operations of this phase we find the paper refill. Before the paper is transferred to the presses, a needle jet generated by a specific nozzle trimms the edges of the dough to obtain the desired size. An imprecise and jagged cutting process at this stage would result in a poor quality end product.

Thanks to the tip with perfectly polished ruby, the orifice of high quality, and their unique design, the GMA nozzles produce a well-defined high-impact needle jet, ideal for achieving a perfect and precise trimming of the edges longer.




Residues of dough and fibres on felt and canvas

At the end of the wet production cycle, when the paper passes to the press area and then to the drying area, the felt and cloth must be washed from any dough residues to continue production.

For this operation, PNR Italia produces two different types of shower pipes:
1. Fixed low-pressure shower pipes (between 2 and 6 bar), with GE fan flat jet nozzles;
2. High-pressure oscillating shower pipes (between 15 and 40 bar), with GEA dart nozzles

Both types are designed with a nozzle cleaning system via an internal shaft equipped with brushes. Our shower pipes can also be combined with oscillation systems to correlate their operation to the speed of the machine.




Static charges in the rolling phase

Once out of the dry area, the paper goes to the rewinding phase: the material is wrapped on itself through a winder called “pope.” The so-called mother coil is formed, a coil weighing several tons with the width of the machine.

In this phase, the speed of the rolling with the paper’s dryness and the material’s rubbing can generate electrostatic discharges, dangerous for the operators and the possible fires that could be developed.

To overcome this problem, it is advisable to install MX atomizers to spray water reduced to very tiny drops in the surrounding air, restoring the necessary balance of moisture that prevents the formation of electrostatic discharges.

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