PPI (PULP & PAPER INTERNATIONAL) MAGAZINE: More grades, more efficient

UPM Nordland Papier in Germany has benefited from a rebuild of its PM 3

May 2007
By Klaus Reimann

UPM Nordland Papier in Dörpen, Lower Saxony, Germany, ranks among the largest fine paper mills in Europe. On its four paper machines and two off-machine coaters, the facility can produce up to 1.4 million tonnes/yr of paper for a huge variety of purposes.

Last year UPM carried out a rebuild of the mill's PM 3.

Lead-up to the rebuild

PM 3 was installed in 1977. It was the first twin wire machine at the mill and the first paper machine with a shoe press.

As part of its global strategy for uncoated woodfree paper, UPM invested Euro 470 million ($570 million) in the new PM 1 at Changshu mill, China, which started up in 2005 and is dedicated to serving the growing Asian market.

Following the completion of work at Changshu, the company turned its focus to Europe, and decided to rebuild PM 1 at UPM Docelles mill in France, as well as PM 3 in Dörpen.

At UPM Nordland Papier, the Euro 82 million rebuild project was aimed at improving output and increasing production. Work began with the extension of the machine hall by 40 m and the installation of a new reel transport system.

In March 2006, the old and new machine halls were connected. PM 3 continued to run throughout these preliminary works.

Between the end of March and May 2006, a new winder was added. The reel cutter and reel transportation were started up together at the end of last May and one week later the old winder was removed.

The paper machine was shut down at the end of July for a rebuild that took 42 days and involved more than 900 people. Many essential parts were replaced, including headbox, fourdrinier and much of the dryer section. Steam and vacuum systems were also revamped. Metso Paper was the main supplier.

The new horizontal dilution headbox is designed to enable better profiles. The old hybrid former was replaced with an OptiFormer HR gap former to increase dewatering possibilities and improve formation, as well as boosting running speed from 1,250 to 1,500 m/min.

An OptiPress was installed in the press section.

This consists of two press nips, with a suction roll press followed by a shoe press, and replaced the old press section, which had an upper shoe press. The new technology was added to increase solids content and paper bulk, and reduce roughness and roughness two-sidedness.

A soft calendar was added after post-drying to help further reduce roughness and roughness two-sidedness.

An OptiReel reeler was purchased to increase the time between jumbo reel changes from 35 minutes to more than one hour. The new reeler can reel over 100,000 m of paper.

A fully automated twin drum winder with a design speed of 3,000 m/min was also part of Metso's scope of supply.

Fig 1. - PM 3 rebuild - cutsize quality

Results of the rebuild

PM 3 is about 20 m longer than before, with an extended pre-drying section. The film press has been moved forward and some new foundations laid.

The revamped machine was restarted on September 14, 2006. It took less than 12 hours to go from stock on wire to (saleable) paper on reel.

PM 3 is more or less a new paper machine with 20% more output.

Before the rebuild the unit exclusively produced copy paper and offset paper. While both grades were very good in terms of their operating characteristics, they were quite two-sided with respect to roughness and it was only possible to effectively produce paper with a low specific volume.

After the rebuild, roughness and two-sidedness has disappeared. In addition, it is now also possible to effectively manufacture products with a higher specific volume, Figure 1. In addition, the 'new' PM 3 has been able to expand its product range to include cutsize in B and B+ quality, B quality preprint format and improved offset products. Table 1 shows the uncoated woodfree portfolio at UPM Nordland Papier, including the new grades produced on PM 3.

Basis weight profiles have been considerably improved as a result of the rebuild. Previously, the profile of an 80 g/m2 cutsize paper produced on PM 3 was rather streaky, with the difference between the maximum and minimum basis weight 4.65 g/m2 and the standard deviation 0.59 g/m2. Now, the profile is significantly smoother and the delta from maximum to minimum basis weight no more than 2.56 g/m2. The standard deviation is 0.42 g/m2.

Ash profiles also show a clear improvement.

High aims have been set for the development of productivity. In December 2006, PM 3 again reached the productivity level it was at before the rebuild. This is a very good achievement considering that new grades have been developed, a bigger range of products is being produced, and that PM 3 is more efficient now than before the rebuild.

Table 2 summarizes the targets and results of the rebuild. As PM 3 climbs up its restart curve, the next targets are to produce even smoother paper with high bulk and increase average production speed further.

Klaus Reimann is product unit director -- woodfree uncoated, UPM Nordland Papier. This article is based on a paper presented at the IMPS 2007 in Munich on March 22.

Pulp & Paper International is FREE to qualified subscribers. Click here to find out more.