Paper machines
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Many modern papermaking machines are based on the principles of the Fourdrinier Machine, which uses a specially woven plastic fabric mesh conveyor belt (known as a wire as it was once woven from bronze) in the forming section, where a slurry of fibre (usually wood or other vegetable fibres) is drained to create a continuous paper web. After the forming section the wet web passes through a press section to squeeze out excess water, then the pressed web passes through a heated drying section.
The original Fourdrinier forming section used a horizontal drainage area, referred to as the drainage table.
Paper machines have four distinct operational sections:
Paper machines are long-lived assets that usually remain in service for several decades. It is common to rebuild machines periodically to increase production and improve quality or to change the paper grade.
Before the invention of continuous paper making, paper was made in individual sheets by stirring a container of pulp slurry and either pouring it into a fabric sieve called a sheet mould or dipping and lifting the sheet mould from the vat. While still on the fabric in the sheet mould, the wet paper is pressed to remove excess water and then the sheet is lifted off to be hung over a rope or wooden rod to air dry. In 1799, Louis-Nicolas Robert of Essonnes, France, was granted a patent for a continuous paper making machine. At the time Robert was working for Saint-Léger Didot, with whom he quarrelled over the ownership of the invention. Didot thought that England was a better place to develop the machine. But during the troubled times of the French Revolution, he could not go there himself, so he sent his brother-in-law, John Gamble, an Englishman living in Paris. Through a chain of acquaintances, Gamble was introduced to the brothers Sealy and Henry Fourdrinier, stationers of London, who agreed to finance the project. Gamble was granted British patent 2487 on 20 October 1801.
With the help particularly of Bryan Donkin, a skilled and ingenious mechanic, an improved version of the Robert original was installed at Frogmore Mill, Apsley, Hertfordshire, in 1803, followed by another in 1804. A third machine was installed at the Fourdriniers' own mill at Two Waters. The Fourdriniers also bought a mill at St Neots intending to install two machines there and the process and machines continued to develop.
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