This may be the digital era, but we use more paper than ever. In the U.S., we will consume over 65 million metric tons of paper and paperboard in 2022. We’re the second-largest consumer of both paper and paperboard, right behind China. As we look for more sustainable means of production and manufacturing, it’s worth looking back on the development of this remarkable, civilization-changing technology. At some point in the future, it’s possible that may not use paper at all. But for an enormous swath of human history, it’s played a starring role.
Here’s a primer, which you’ll probably not be reading on paper. It starts with papyrus, the first paper-like material —made, just as it sounds, from the papyrus plant in ancient Egypt. In China in the 8th century BC, scribes wrote on sheets made from mulberry leaves, fishnets, old rags and hemp waste. The first actual “paper” was invented around 105 by Cai Lun, a court official, who used a variety of plant fibers and a fine mesh screen.
By the 3rd century, paper was a common writing medium; the 6th century saw the emergence of toilet paper; and in 600 in China, paper was first folded and sewn into tea bags. The first government-issued paper-printed money happened in 960, also in China.
In the 8th century, papermaking spread to the Islamic world, where techniques were developed and refined to manufacture paper in bulk. Paper makers soaked, cooked, rinsed and beat fibers from the inner bark of various plants to form paper pulp, figured out how to make thicker sheets, and began using water-powered paper mills. The results were used for writing, printing, book art, and three-dimensional work.
Paper Grows Up
Papermaking came to Europe in the 11th century, and paper quickly replaced parchment and wood panels for writing and art. From there, some clear milestones pushed the technology forward. By 1300, papermaking molds were constructed with wire. Hemp and linen rags were used as raw materials. But it was the invention of moveable type in printing that transformed papermaking into an industry. By the 14th century, paper mills spread across Spain, Germany, France, and Italy. Soon, hemp and rags were replaced by inexpensive cotton from Africa and America; wood pulp became the material of choice in 1843.
However, until the invention of a continuous papermaking machine, paper production remained labor-intensive. It went through five basic steps (and paper is still made this way), but each sheet had to be made individually:
- Fiber is separated from the rest of the raw materials (such as cellulose from cotton rags or wood).
- Fiber is beaten into a pulp.
- Color and other properties are adjusted using a form of chemical.
- The slurry is screened to separate the fibers.
- The material is pressed and dried into paper.
To make a sheet of paper, a rectangular frame or mold with a screen bottom was dipped into a vat of pulp. The frame was removed from the vat and the water pressed out of the pulp. The remaining pulp was allowed to dry — and the frame could not be reused until the previous sheet of paper was removed from it, so there was a limit to how many sheets could be made during the same time period.
The Rise of Papermaking Machines
But in 1798, that began to change. Nicholas Louis Robert, working in France, patented a moving screen belt that could be fed with a continuous flow of pulp slurry, creating a wet mass on a moving screen. That could be transformed into an unbroken sheet of wet paper. Then in 1807, two engineers working for Henry and Sealy Fourdrinier improved upon Robert’s machine, got a patent, and thus initiated the dawn of the modern papermaking machine — named the Fourdrinier machine.
Engineers in France and England worked separately to design, construct, and operate a papermaking machine that could run continuously at high speed to make paper that would issue from a series of drying rolls at the end of the machine. Initially, the machine was fed rag pulp, but that changed to bleached wood pulp. The first commercially working machine was named Fourdrinier, after the main investor.
Surprisingly, little has changed since the mid-1800s. The process is basically the same, though now it’s done on a massive scale. Wood chips are created from trees such as spruce, pine, fir, larch, and hemlock, and hardwoods such as eucalyptus, aspen, and birch. The chips are “cooked” with sulfuric acid in a high-temperature, high-pressure digester. Then, the hot mixture is discharged forcefully against a metal plate, freeing the cellulose fibers from the organic “glue” (lignin) that holds them in the growing wood. The hot organic liquid mixture is used to generate useful steam before it’s disposed of. Then the separated, still-colored fibers, now called wood pulp, are washed, bleached, and dumped onto a series of rapidly moving and shaking screens, where the water and very small fibers fall through, leaving a thick material — which keeps shedding water as it moves at high speed (several hundred feet per minute).
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Color, finish, and other characteristics are created with additives, such as titanium dioxide, to whiten the paper and calcium carbonate as filler, among a whole host of others. Then the moist mat was fed into a series of very hot drying rolls until, by the last roll, it was now paper. It’s wound on finishing rolls. And while rag paper is still made by hand for special uses, this is how nearly all paper is made. The evolution has essentially gone in a straight line since its inception — another example of inventors building on previous innovations, each adding another piece of the puzzle. Perhaps, given the need to reduce paper’s environmental impact and decrease waste, we’ll see yet more innovations in the future.
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Peter H. Spitz immigrated to the U.S. from Austria in 1939 and embarked on a long career in the energy and chemicals industry with seven of his own scientific patents. He was the founder and CEO of Chem Systems, Inc. and a frequent lecturer at MIT. Always passionate about innovation, he became a scholar of our industrial past and has authored numerous books and articles. His new book is Reflecting on History: How the Industrial Revolution Created Our Way of Life.
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