Where our wood comes from
The basis for the manufacture of our textile pulp is spruce wood from sustainable forestry in the European Union. In accordance with PEFC and FSC standards, the majority of our requirements of around 900,000 solid cubic metres each year comes from Germany and Austria, with smaller quantities coming from Eastern Europe. The largest proportion of our wood is sawmill residue from sawmills.
Digester is the first step
To produce textile pulp, the wood chips, which have been stored in the lumberyard for an average of 5 weeks, are broken down chemically under high temperatures and high pressure, as well as with the addition of magnesium bi-sulphite acid (chemical formula Mg(HSo3)2) in digesters. Seven digesters with a capacity of 225 cubic metres each are used to make continuous processing possible. During the cooking process, the link between the individual wood fibres is weakened, the lignin and the hemicellulose are dissolved in the cooking acid, and the insoluble cellulose fibres are then separated from the boiling acid. The so-called “brown liquor” is purified in the fibre line:
Our environmentally-friendly bleaching process in the fibre line
In the fibre line, the brown stock is first sorted in a pressure screen with 4 stages to separate solid wood chips and knots as well as sand particles from the fibrous material. The fibrous material is then washed and chemically bleached. During the chemical bleaching stages with sodium hydroxide, oxygen, hydrogen peroxide and ozone as well as washing stages, the brown stock is prepared in such a way that the highest possible proportion of pure cellulose remains. Pulp for paper production generally has a purity level of 88 percent, viscose pulp has a purity of up to 96 percent, depending on the type. Around 40 percent of the quantity of wood used becomes the overall yield of textile pulp.
After bleaching, the pulp suspension is de-watered in a wire and press section and then dried. This takes place in the adapted 4-metre wide paper machine ZEM3: After dewatering by using a vacuum, conventional press sections and dewatering with a shoe press, the dry content of the pulp quantity is brought to around 50 percent. The remaining moisture is removed using steam-heated cylinders. The pulp quantity is wound up around a steel core (tambour) and 20 tons of pulp from each is handed down for processing.
The customer format
In the so-called bale line, the pulp quantity is cut into individual pulp sheets and packed into bales. In this way, 470 tons of pulp are produced around the clock each day. The pulp is transported by train to Koper and Bremerhaven twice per week where it starts its journey by sea to Asia.
The features of special pulp from Hallein
- Highly pure pulp made from spruce wood (long fibre)
- Highest stability in processes and product quality
- Environmentally friendly, completely chlorine free (TCF) manufacturing process
- Supplied in bales and rolls
- Wood from sustainably managed, certified forests (PEFC and FSC)
The application areas of special pulp
- Performance 94-550 for the manufacture of viscose fibre
- Performance 95-550 for the manufacture of viscose yarns
- Performance 95-630 for the manufacture of nitrocellulose, cellulose ether, micro-crystalline cellulose, sausage casings and other special applications