Pulp mills commercial pulping methods

Another important event could have been chosen on which to base a centennial—the invention of the sulfite pulping process by the Tilghman brothers in Philadelphia. Although dated as 1866 when a British patent for the process was issued, successful laboratory experiments had been made in 1865. In their attempts to adapt the new method to commercial scale, the Tilghmans tried to develop a continuous process but unfortunately could not solve the technical problems involved. A few years later, at the beginning of the 1870 s, experiments on sulfite pulping were taken up in several places in Europe, and in 1874 the first sulfite pulp was produced commercially by C. D. Ekman in a Swedish mill. 

The soda method was also attempted in Finland in the 1870s and early 1880s. Theodor Hoffding and another Danish engineer were involved in setting up the first two pulp mills close to Viipuri, near the eastern border. However, commercial production first started in 1886 in the Walkiakoski paper mill, a Finnish company in the western part of the country that employed the sulphate process. Due to technical setbacks, the output remained modest for many years. Paper mills in Nokia and Kuusankoski adopted the other process, sulphite pulping, in 1885, and succeeded much better. Imitators followed, and for several decades that process dominated chemical pulping in Finland. ... 

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