Karlsborg Mill: The Story of the World’s Northernmost Paper Mill

A Tumultuous Start

The history of Karlsborg Mill began in 1914 when the Baltic Wood Products Company was formed, and the sulphate factory in Karlsborg was built. The factory started in 1914 but, due to poor profitability, it was closed in 1918, and the machines were sold to Finland. Many believed that industrial activity in Karlsborg would never resume. However, through strong commitment from the local community and a broad effort to purchase shares, the Kalix Wood Industry AB was founded in 1928 and industry in the region was revived. Despite this shaky start, the mill developed with great success.

On July 20, 1929, the new sulphate factory started production, reaching an annual production of 15,800 tons of pulp the following year. In 1939, a mesoburning and rotating drying kiln system was erected, with increased capacity the following year. The third soda recovery unit came into operation in 1940, later replaced by modern air condensate machines. In 1945, a brand-new pulp warehouse with fireproof construction, considered the most modern in the country, was built.

Over the years, pulp production has gradually increased. In 1930, it was 15,000 tons per year, increasing to 20,000 tons in 1942, and reaching today’s production capacity of approximately 350,000 tons per year.

The Paper Mill: Modernization and Growth

The construction of the paper mill began in 1951. The first paper machine, PM1, started operating in January 1953, followed by PM2 four years later. PM2 is still in operation, while PM1 was shut down at the end of February 1992. The decommissioned machine has now been rebuilt and has been used since April 1993 for coating kraft paper and liner. The capacity is around 40,000 tons per year. After extensive modernization in the fall of 1996 and other improvement measures, PM2’s current capacity is approximately 130,000 tons per year.

During the 20th century, Karlsborg Mill underwent significant modernizations. In 1979-1980, 610 million SEK were invested in the modernization of the pulp mill. A new fiberline, evaporation system, soda recovery boiler, and bark boiler were installed. A new wood cleaning facility came into operation in 1985, and the company started using modified cooking that same year, reducing chlorine pollutant emissions.

The pulp produced at the mill today is used for the manufacture of bleached sack and kraft paper, and also sold to other paper manufacturers.

Sustainability and Society

With around 400 employees, Karlsborg Mill is a significant employer in the region and has played a crucial role in the local community through sponsorship and involvement in various associations for culture, sports, gender equality, and community engagement.

On the environmental front, many improvements have been made over the years. In 1985, the company started using modified cooking, reducing chlorine pollutant emissions. In September 1991, the mill introduced an oxygen bleaching process, and in December of the same year, the use of chlorine gas in bleaching was discontinued, leading to a significant reduction in chlorine pollutant emissions from the bleaching process. In early 1997, an electrofilter on the bark boiler came into operation, helping to separate dust from the flue gases. In 1999, a strong gas boiler was put into operation, significantly reducing sulfur and hydrogen sulfide emissions, thereby reducing the odor from the factory.

In the fall of 2004, a large part of the fuel oil was replaced with pitch oil. This is one of the measures taken to reduce oil consumption from approximately 46,000 cubic meters per year in 1980 to the current level of about 2000 cubic meters. At the end of 2006, a new larger turbine was put into operation, enabling the mill to produce about 75% of the electricity it needs.