Short History of Papermaking
Paper is manufactured on a Fourdrinier Machine, in a process invented in 1798 by Nicholas-Louis Robert, while working for the French paper mill owned by the Didot family. His machine used a belt of wire screen to produce a continuous web of paper. He was backed in England by the Fourdrinier brothers, who built and sold the first paper machines.

By 1810, the Fourdrinier brothers found themselves in bankruptcy and Bryan Donkin, their engineer, continued to improve the basic design. Soon he was successfully manufacturing a machine that mechanized the process of making paper. A water and pulp mixture flowed across a moving, vibrating web of woven wire cloth, forming a wet mat of interlocking fibers. From the wire, the newly formed paper transferred to a moving web of woolen cloth (the felt), before being dried.

Today a mixture of water and pulp still flows on the Fourdrinier wire, but the size and scale of today's papermaking operations bear very little resemblance to the early machines. The process is highly automated, with high-speed metering devices, incredibly refined chemistry, and precision built into every aspect of the operation.

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Paper Manufacturing

Stock Preparation
One of the most important aspects of papermaking takes place in large beaters before the paper machine. Each paper requires its own special mix of fibers and fillers to achieve its unique characteristics. The furnish, which consists of the finest available wood pulps, fillers, and internal sizing, is mixed with water in large beaters until the mixture (a slurry called stock or stuff) resembles oatmeal.

Wet End
The slurry is about 99% water and 1% fiber. It moves from the headbox, which evenly distributes the mixture onto a fine wire mesh (wire). The wire travels at speeds of up to 1,800 feet per minute. A gentle shaking motion on the wire mats the fibers together. Water drains off as the wire moves forward.

Dandy Roll
Rides on top of a moving web of paper. Its functions are to help remove water from the web and to lay down and compact the fibers. May also be used for watermarking via designs in wire sewn to its surface, or for reproducing the surface of laid paper by a laid watermark.

Couch Roll
The partially dry web of paper leaves the wet end of the paper machine here. It is now strong enough to support itself.

Press Section
The paper at this point is still about 50% water. For genuine felt marks, the paper web is run against special textured marking felts, which impart their finish to the paper.

Dryer Section
Most of the remaining moisture is removed from the paper by steam-heated drums.

Size Press

In this section, surface sizing is added to uncoated paper to provide surface strength and to prevent feathering and picking when ink is laid down in the offset printing process.

Coater
The coating process can be performed either while the paper moves through the papermaking machine, or when it comes off of the machine. Coating improves ink holdout, reducing dot gain, for creating sharper, brighter printed images.

Calendering
The calender stack controls the caliper, smoothness, and gloss of paper.

Winder
Paper is wound up into rolls and taken off the paper machine.

Finishing
Paper is cut into smaller web rolls, precision-sheeted, and packed in cartons or on skids.

The Ingredients of Papermaking

Broke
Paper manufactured by the mill that has been discarded at some point during the process. It is returned to a repulping unit for reprocessing.

Calcium Carbonate
A mineral (ground marble) alkaline filler which may act as a buffer. It also increases the brightness of a grade.

Cotton
Cotton fibers, composed entirely of pure cellulose, may be used in papermaking. Paper formerly made from rags is today made from cotton fibers.

Dyes & Colorings

Color is added and monitored continually during the papermaking process. Sophisticated computers ensure consistency through the run and in subsequent runs.

Fillers
Nonfibrous, insoluble mineral materials added to the fiber furnish to impart specific properties such as opacity, improved ink receptivity, whiteness, or surface smoothness. Commonly used fillers include clay, calcium carbonate and titanium dioxide.

Postconsumer Fiber (Recycled Paper)
With the heightened interest in recycling, postconsumer fiber has gained new importance as a key ingredient in fine papers. One solution to the earth's waste problem is adding used paper from homes and offices to the paper furnish as postconsumer fiber.

Pulp
Cellulose fibers from wood or other plant sources may be extracted chemically or mechanically. Softwood pulps are derived from conifers (evergreens). Hardwood fibers (from deciduous trees) are also a primary source of papermaking pulp.

Sizing
Internal sizing improves water resistance so that the paper fibers stay together on handling. Surface sizing applied to the partially dry web increases surface strength and resistance to ink spread or feathering.

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