The first modern paper machine was invented by Louis-Nicolas Robert in France in 1799, and an improved version patented in Britain by Henry and Sealy Fourdrinier in 1806.
Didot believed that England was a better place to develop the machine but due to the turbulence 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.
With the help of Bryan Donkin, a skilled and ingenious mechanic, an improved version of the Robert original was installed at Frogmore Paper Mill, Apsley, Hertfordshire, in 1803, followed by another in 1804.
Thomas Gilpin is most often credited for creating the first U.S. cylinder type papermaking machine at Brandywine Creek, Delaware in 1817.
[1] Records show Charles Kinsey of Paterson, NJ had already patented a continuous process papermaking machine in 1807.
The cutting process terminates when the mix has passed the cylinder enough times at the programmed final clearance of the knives and bed.
The kraft process, due to the alkali and sulphur compounds used, tends to minimize attack on the cellulose and the non-crystalline hemicellulose, which promotes bonding, while dissolving the lignin.
Groundwood, the main ingredient used in newsprint and a principal component of magazine papers (coated publications), is literally ground wood produced by a grinder.
Thermomechanical pulp (TMP) is a variation of groundwood where fibres are separated mechanically while at high enough temperatures to soften the lignin.
Bales of recycled paper (normally old corrugated containers) for unbleached (brown) packaging grades may be simply pulped, screened and cleaned.
Recycling to make white papers is usually done in a deinking plant, which employs screening, cleaning, washing, bleaching and flotation.
Stock preparation is the area where pulp is usually refined, blended to the appropriate proportion of hardwood, softwood or recycled fibre, and diluted to as uniform and constant as possible consistency.
Historically these were made of special ceramic tile faced reinforced concrete, but mild and stainless steels are also used.
Refining is an operation whereby the pulp slurry passes between a pair of discs, one of which is stationary and the other rotating at speeds of typically 1,000 or 1,200 RPM for 50 and 60 Hz AC, respectively.
[6][7][8] The purpose of the headbox is to create turbulence in order to keep the fibers from clumping together and to uniformly distribute the slurry across the width of the wire.
[7][8] On lower speed machines at 700 feet per minute, gravity and the height of the stock in the headbox creates sufficient pressure to form the jet through the opening of the slice.
On slower machines where sufficient liquid remains in the stock before draining out, the wire can be driven back and forth with a process known as shake.
The couch roll is a hollow shell, drilled with many thousands of precisely spaced holes of about 4 to 5 mm diameter.
[7][8] Ultrasonic foils can also be used, creating millions of pressure pulses from imploding cavitation bubbles which keep the fibres apart, giving them a more uniform distribution.
Approaching the dry line on the table are located low vacuum boxes that are drained by a barometric leg under gravity pressure.
[7][8] The forming section type is usually based on the grade of paper or paperboard being produced; however, many older machines use a less than optimum design.
This is not considered a separate ply because the water action does a good job of intermixing the fibers of the top and bottom layer.
[12] Pressing is the second most efficient method of de-watering the sheet (behind free drainage in the forming section) as only mechanical action is required.
They are made up of a polyamide woven fabric with thick batt applied in a specific design to maximise water absorption.
Additional sizing agents, including resins, glue, or starch, can be added to the web to alter its characteristics.
Some paper machines also make use of a 'coater' to apply a coating of fillers such as calcium carbonate or china clay usually suspended in a binder of cooked starch and styrene-butadiene latex.
To accomplish this the reel is placed on an unwind stand and the distances between the slitters (sharp cutting wheels), are adjusted to the specified widths for the orders.
Acid paper deteriorates over time, which caused libraries to either take conservation measures or replace many older books.
stock: a pulp slurry that has been processed in the stock preparation area with necessary additives, refining and pH adjustment and ready for making paper web: the continuous flow of un-dried fiber from the couch roll down the paper machine white water: filtrate from the drainage table.