Description:

The scope of the mill are mainly two paper machines, PM 3 and PM 4, beside pulp preparation, grinding plant, rewinding machines and packing machines.

Recovery fibre and pulp preparation.

The scope of pulp preparation and recovery fibre line is equipment particular suitable to handle plastic-coated paper as e.g. milk carton. Capacity for the recovery fibre line is approx. 50 tons / day based on plastic-coated paper. Until now the production has been approx. 30 t/day.

When using simple recycled paper quality as recycled corrugated cardboard (OCC, old corrugated containers) the estimated increased capacity is approx. 150 t/day depending on shorter dwell time in the working process, especially in the pulper.

Pulp preparation consists of two lines, one for dissolving purchased market pulp and the other for recovery fibre preparation. All equipment in both pulp preparation lines are components from many different machine suppliers and the lines has been built gradually.

Virgin pulp line

The pulp line mainly consists of a conveyor and an Escher Wyss pulper for dissolving. The pulp is pumped from the pulper to pulp towers before the paper mill. The line was installed by Höystad/Jylhävaara 1980. The line is continuous and the capacity is approx. 55 t/day.

Recovery fibre line

The recovery fibre line consists of several stages. At the first stage the waste paper is fed to a hammer mill (BOA) for grinding into bigger flakes. It is necessary to do this decomposition to make it possible to dissolve plastic coated paper. Next step is to compress the waste paper whereupon it is dissolved in an Escher Wyss pulper with MC-conditions. The dwell time in the pulper for dissolving the waste paper is about 30 minutes. The pulper is running batch wise and has a capacity of approx.1,600 kg / batch.

After dissolving the suspension is moved with a worm conveyor to a drum washer for plastic separation (Kufferath). The separated plastic is then moved to a screw compressor for further transport to the nearby refuse disposal unit for combustion. The recovery pulp suspension is transported from the plastic separation unit to a turbo separator for coarse screening and from there to a Escher Wyss S4 pressure screen (fine screen) with 0,18 mm slots.

The rejects from the fine screen goes to a Escher Wyss Reject Sorter for fibre recovery.
After that stage the reject is taken via a pulp chest to a HC cleaner (centricleaner) for further fibre recovery.

In 2004 a disperse stage as well as cleaners (centricleaner) was installed. This process stage is used to grind up remaining contamination.

In relation to pulp preparation certain chemicals is added, especially calcium carbonate (CaCO3) and titanium dioxide (TiO2).

The dwell time in the pulper, which is about 30 minutes, is to ensure that as much plastic as possible is removed from the fibre. For more easily dissolvable recovery paper as OCC, dwell times under 10 minutes should be enough.

Towers / tanks

The market pulp and recovery pulp is pumped from pulp preparation to five different pulp towers before the paper machines. Four of these towers have a volume of approx. 250 m³ each and the tower for recover pulp has a volume of approx. 500 m³. The concentration in the towers is as low as 3-4 % as the agitator’s doesn’t handle higher concentration. Beside these towers there is a tank for pulp water.

Stock preparation

From pulp towers the pulp is pumped at relatively low concentration (approx. 3 %) to dewatering filter (drum filter) to higher the concentration (to approx. 5 %). Stock preparation consist of Sprout Waldron disk refiners (4 units) and an Escher Wyss conical refiner. Chemicals as aluminium sulphate (Al2(SO4)3) and magnesium sulphate (MgSO4) as well as colours can be added.

Before PM 3 the pulp is screened through a Noss pressure screen as well a Noss centrisorter package (centricleaner). Before PM 4 the pulp is screened through a Bird screen and through a relatively big centricleaner (Rickard Berg) for sand separation.

Paper machines

PM 3 is a fourdrinier machine with main components from Erwepa which has produced coloured and uncoloured printing and writing paper based on recovery fibre which to a great extent has consisted of plastic-coated cardboard. The annual capacity has been approx. 20 000 tonnes. The production has lately been focused on simplified paper and

cardboard with basis weight from 75 to 320 g / m2. The production from PM3 has mainly been for the local market.

Machine speed is 80 – 255 m/min.

PM 3 can easily be converted for production of liner and fluting, when the capacity can be increased to at least 30 000 tonnes annually (approx. 4 tonnes/h).

PM 4 is a fourdrinier machine with main components from Erwepa and have produced MG-paper (’Machine-Glazed’) based on virgin pulp (Purchased chemical pulp). The annual capacity has been approx. 14 000 tonnes. Lately the machine has produced MG-paper based on very successfully developed recovery fibre. The main production on PM4 is bag paper and other white MG-paper.

Finishing department

To each paper machine there is a rewinding machine (Jagenberg Vari-dur from 1965 for PM 3 and a Beloit from1989 for PM 4). The Jagenberg Vari-Dur-machine has a width of 257 cm, but the knife rolling has a width of 249 cm.

After the paper machines there is waste line with a guilliotine (Metrans) and a broke pulper. Also there is roll wrapping line (Jagenberg / BUMA). A part of the production (max. approx. 25 tonnes / day) has been cut into sheets and packed. The sheet cutting line is from Jagenberg.

Certain sheet cutting is done on a Jagenberg sheet machine with sheet length and width of max 1,650 mm and min. 450 mm. The machine can run at 250 m / min. Knifes allows max. 500 g / m2, total basis weight, can be cut. The reel stand handles max. 4 rolls. Max. approx.25 tonnes / day can be cut.

A compressibility line (Presonas) with a baling press for waste paper from rewinding machines and sheet cutting is also installed at the finishing department.

Additional equipment

Other equipment available in the mill are two oil fired steam boilers with a capacity of 12 ton steam per hour each. An electric boiler from 1984 with a capacity of 12 MW. The steam pressure from the boilers are 9 bar.

Moreover there is a feed water preparation including sand filter and water softener available. An air compressor, certain electrical equipment (transformer), spare part stock and laboratory outfit.