Modern paper manufacturing at the Hudson River Mill utilized production technologies that remained essentially unchanged since the 19th century. The central technology was the Fourdrinier paper machine patented in France in 1799. The Fourdrinier process works by distributing highly liquefied wood pulp across a wide, moving mesh screen to produce a continuous sheet of paper. Water is removed from the pulp by suction from beneath the screen, leaving behind highly concentrated wood pulp that forms a sheet on the screen. The sheet then moves over a felt and through a dryer section that removes the remaining moisture before it is taken up on a roll at the "dry end" of the paper machine.

The technology that was perhaps most critical to the success of the Hudson River Mill was the Keller-Voelter wood pulp grinder developed in Germany in the 1840's. It was this technology that Alberto, Albrecht, and Rudolph Pagenstecher transferred to the United States in 1866 and first utilized at Curtisville, Massachusetts in 1867. The mechanical production of paper pulp from wood - commonly referred to as "groundwood" - revolutionized the paper industry by providing an inexpensive replacement for the cotton rags and straw that were then the principal ingredients of paper. Limited forest resources and insufficient waterpower in the Berkshires, however, soon drove the Pagenstechers from Curtisville to Palmer Falls on the Hudson River where abundant natural resources permitted them to scale up the production of wood pulp and also manufacture paper at the same site.

The development of chemical pulps in the middle decades of the 19th century also played a vital role in the modern paper manufacturing process at the Hudson River Mill. The sulphite process works by the preliminary break-down of pulpwood into small "chips" that are then cooked under high pressure in an acid solution. All the soluble matter in the wood is dissolved in the process, leaving pure cellulose fiber to serve as paper pulp. Although more expensive to produce than mechanical pulp, sulphite pulp was used with groundwood to add strength to the paper sheet.

There are numerous additional technologies that have contributed to modern paper manufacturing which are explained in the documents available on this page. The texts shown - viewable as PDF documents - represent a small sampling of the publications produced by International Paper and the Hudson River Mill during the 20th century to explain the paper manufacturing process. In some cases, content unrelated to the production process has been omitted from these documents.

Please Note: A silent, 13-minute motion picture created at the Hudson River Mill in 1919, entitled "The Manufacture of Paper," will soon be viewable from this page.