15 Nov. 2021. It’s going on the long and fruitful collaboration between Cartiere di Trevi, a paper mill with a long history and tradition, specialized in high quality cardboard products, and De Iuliis C.& A., manufacturer of machines and systems for the paper industry that has been operating in the sector for more than 66 years, with a very loyal clientele, both Italian and foreign.
Cartiere di Trevi works paper basis weight from 140 up to 600 gsm, with working width of 2,300 mm and design speed of 600 m/min for the production of paper for corrugating, honeycomb paper, recycled medium colored paper and coreboard made using 100% waste paper as raw material, in a perfect circular economy system.
His young and active management has made in these years several investments in order to achieve better paper quality and higher production capacity.
In the fourth quarter of 2020, De Iuliis carried out a press section rebuilt to overcome previous production limits. De Iuliis design goal had to be the paper width increasing at the pope reel, improving the paper mechanical characteristics and the paper machine runnability, with contractual guarantee on the dryness increasing.
A re-design of the press section was made, in order to fit wider press rolls in the narrow space of the existing machine, modifying the rolls positioning and arrangement to optimize the spaces according to the modern concepts. The open draw between the presses has been shortened, to reduce the stress of the paper before the press to generate beneficial effects on mechanical paper characteristics and to have a better runnability of the complete paper machine.
Great importance has been given to the choice of specific covers for the new press rolls. After a long and extensive analysis based on the specific Cartiera di Trevi production range, the best ones have been identified and applied. The result was an improvement of the press section Nip with an enlargement of the paper width and a further important qualitative and economical advantage because the higher dryness after the press section.
The fourdrinier wire geometry has been also modified with the aim to introduce a new vacuum cylinder which now guarantees higher water removal in the wire section with improvement of dryness before press section and paper machine runnability.
Last, but not least, a higher bulk has been achieved. The compaction of the sheet causes a reduction of its thickness; the ratio between thickness and grammage of the sheet, called bulk, is an important characteristic for both printing papers and boards, because with the same grammage, a thicker sheet has greater rigidity and, therefore, better mechanical characteristics. The bulk increasing is one of the most important goal for every paper mill to be achieved,
The modernization of the paper machine was a total turn-key project, also included the engineering and the supply of the vacuum system related to the wire and press section modification, complete with erection assistance, commissioning and start-up.
Paper Mill manager, Mr. Franco Graziosi, shares his views on the results obtained in collaboration with De Iuliis.
Why did you choose De Iuliis for this work?
De Iuliis has been assisting us for many years not only as a supplier of plants and machinery, but as an indispensable partner to support above all the search for engineering solutions to improve the performance of our plants. In this case, it seemed natural to us to trust the project which, 7 months after its start-up, has beaten the expected targets by far.
What have you achieved with this rebuilt?
We expected improvements in dryness exiting the first dryer, an optimization of the manufacturing at higher weights with a better profile and in particular the control of the drainage on the nip. The results have been satisfactory from day one and the characteristics of the paper have also improved.
How would you describe your cooperation with de Iuliis?
We are very satisfied about the results just reached after this modification and, to confirm this, the end of the continuous machine line (winder-pope) is already being updated by the end of the year.