How is pulp made?
To make pulp from wood, a chemical pulping process separates lignin from cellulose fibre. A cooking liquor is used to dissolve the lignin, which is then washed from the cellulose; this preserves the length of the cellulose fibres. Paper made from chemical pulps are also known as wood-free papers (not to be confused with tree-free paper ); this is because they do not contain lignin, which deteriorates over time. The pulp can also be bleached to produce white paper, but this consumes 5% of the fibres. Chemical pulping processes are not used to make paper made from cotton, which is already 90% cellulose.
Why is paper yellow?
Paper made from mechanical pulp contains significant amounts of lignin, a major component in wood. In the presence of light and oxygen, lignin reacts to give yellow materials, which is why newsprint and other mechanical paper yellows with age. Paper made from bleached kraft or sulfite pulps does not contain significant amounts of lignin and is therefore better suited for books, documents and other applications where whiteness of the paper is essential.
What was the most common source of fibres before the industrialisation of paper production?
See also: wood pulp and deinking. Before the industrialisation of paper production the most common fibre source was recycled fibres from used textiles, called rags. The rags were from hemp, linen and cotton. A process for removing printing inks from recycled paper was invented by German jurist Justus Claproth in 1774.
What is paper made of?
Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distributed on the surface, followed by pressing and drying. Although paper was originally made in single sheets ...
What was the impact of industrialization on the cost of paper?
In the 19th century, industrialization greatly reduced the cost of manufacturing paper. In 1844, the Canadian inventor Charles Fenerty and the German inventor Friedrich Gottlob Keller independently developed processes for pulping wood fibres.
Why is alum used in paper?
Alum was added to paper to assist in sizing, making it somewhat water resistant so that inks did not "run" or spread uncontrollably. Early papermakers did not realize that the alum they added liberally to cure almost every problem encountered in making their product would be eventually detrimental. The cellulose fibres that make up paper are hydrolyzed by acid, and the presence of alum eventually degrades the fibres until the paper disintegrates in a process known as " slow fire ". Documents written on rag paper are significantly more stable. The use of non-acidic additives to make paper is becoming more prevalent, and the stability of these papers is less of an issue.
How to dry paper?
Drying involves using air or heat to remove water from the paper sheets. In the earliest days of papermaking, this was done by hanging the sheets like laundry; in more modern times, various forms of heated drying mechanisms are used. On the paper machine, the most common is the steam-heated can dryer.
What is the difference between papyrus and paper?
In contrast to paper, papyrus has an uneven surface that visibly retains the original structure of the ribbon-like strips that make it up. As the papyrus is worked, it tends to break apart along the seams, leading to long linear cracks and eventually falling apart.
What is the name of the paper that was used to write?
Papyrus is a thick, paper-like material produced from the pith of the Cyperus papyrus plant which was used in ancient Egypt and other Mediterranean societies for writing long before paper was used in China. Papyrus is prepared by cutting off thin ribbon-like strips of the interior of the Cy perus papyrus, and then laying out ...
How does paper compare to papyrus?
Paper contrasts with papyrus in that the plant material is broken down through maceration or disintegration before the paper is pressed. This produces a much more even surface, and no natural weak direction in the material which falls apart over time.
When was papermaking invented?
By the 13th century, papermaking was refined with paper mills utilizing waterwheels in Spain. Later European improvements to the papermaking process came in the 19th century with the invention of wood-based papers.
When did papermaking spread to the Islamic world?
During the 8th century, Chinese papermaking spread to the Islamic world, where pulp mills and paper mills were used for papermaking and money making. By the 11th century, papermaking was brought to Europe. By the 13th century, papermaking was refined with paper mills utilizing waterwheels in Spain.
Why were paper mills required?
Due to their noise and smell, paper mills were required by medieval law to be erected outside the city perimeter. The use of human and animal powered mills was known to Chinese and Muslim papermakers. However, evidence for water-powered paper mills is elusive among both prior to the 11th century.
How did paper affect Chinese culture?
According to Timothy Hugh Barrett, paper played a pivotal role in early Chinese written culture, and a "strong reading culture seems to have developed quickly after its introduction, despite political fragmentation." Indeed, the introduction of paper had immense consequences for the book world. It meant books would no longer have to be circulated in small sections or bundles, but in their entirety. Books could now be carried by hand rather than transported by cart. As a result, individual collections of literary works increased in the following centuries.
What is blotting paper?
Blotting paper is a paper variety that has high absorbency and can be used to remove excess liquids from objects or surfaces. This can include the absorption of excess ink, the removal of excess liquid from a microscope slide prior to being viewed, or even the removal of excess oil from a person’s skin.
What is acid free paper?
Acid-free paper is created using a alkaline production process that removes the lignin from the wood pulp and treats the pulp solution with a mild base such as calcium bicarbonate, to produce a pH that is above 7. Acid-free paper is designed to be used in cases where it is important to preserve the documents over long time periods without aging, yellowing, or deteriorating.
What is envelope paper?
Envelope paper. Envelope paper is used to create different styles of envelopes for the storing and mailing of documents or other objects. The finished form of envelopes may call for the addition of adhesives for closing the envelope, or other clasps or mechanisms to secure the contents inside the envelope.
What is copy and copier paper?
Copy & copier paper is used for printers, photocopiers, fax machines, and other general-purpose office and home uses. There are specialized types of these papers as well that are designed to be better suited for printing using either inkjet or laser printer technologies.
What is archival paper?
Archival paper. Like acid-free paper, archival paper is also used for maintaining the quality of documents over time. In addition to being acid free, much archival paper is made using 100% cotton instead of wood pulp to help preserve the.
What is drinking cup paper?
Drinking cup paper is used to create single-use, disposable paper cups that hold water or other liquids. They use wax or similar coating to reduce the tendency for the absorption of liquids by the paper.
What is chart paper used for?
Chart paper also referred to as recording chart paper, is used in chart recorders that monitor a variety of conditions including electrical power, temperature and weather conditions, earthquake activity, or medical conditions such as cardiac output (electrocardiography) or brain activity (electroencephalography). It also finds application in monitoring activity and conditions in cleanrooms.
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What is paper made of?
Remember that paper is made out of trees. Thus, paper is made mostly out of organic compounds: that is carbon, hydrogen and oxygen (C, H and O). Paper also contains non organic materials to improve its properties. These may be chalk (CaCO 3) and kaolin clay (Al 2 Si 2 O 5 (OH) 4 ). Titanium oxide (TiO 2) is also commonly used in paper ...
Is paper a chemical or physical symbol?
There is no chemical symbol for paper since it is not an element but rather a mixture of several different compounds.
Overview
Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distributed on the surface, followed by pressing and drying. Although paper was originally made in single sheets by hand, almost all is now made on large mac…
History
The oldest known archaeological fragments of the immediate precursor to modern paper date to the 2nd century BCE in China. The pulp papermaking process is ascribed to Cai Lun, a 2nd-century CE Han court eunuch.
It has been said that knowledge of papermaking was passed to the Islamic world after the Battle of Talas in 751 CE when two Chinese papermakers were …
Early sources of fibre
Before the industrialisation of paper production the most common fibre source was recycled fibres from used textiles, called rags. The rags were from hemp, linen and cotton. A process for removing printing inks from recycled paper was invented by German jurist Justus Claproth in 1774. Today this method is called deinking. It was not until the introduction of wood pulp in 1843 that paper production was not dependent on recycled materials from ragpickers.
Etymology
The word paper is etymologically derived from Latin papyrus, which comes from the Greek πᾰ́πῡρος (pápūros), the word for the Cyperus papyrus plant. Papyrus is a thick, paper-like material produced from the pith of the Cyperus papyrus plant, which was used in ancient Egypt and other Mediterranean cultures for writing before the introduction of paper. Although the word paper is etymologically derived from papyrus, the two are produced very differently and the development …
Papermaking
To make pulp from wood, a chemical pulping process separates lignin from cellulose fibre. A cooking liquor is used to dissolve the lignin, which is then washed from the cellulose; this preserves the length of the cellulose fibres. Paper made from chemical pulps are also known as wood-free papers (not to be confused with tree-free paper); this is because they do not contain lignin, whic…
Applications
Paper can be produced with a wide variety of properties, depending on its intended use.
• For representing value: paper money, bank note, cheque, security (see security paper), voucher, ticket
• For storing information: book, notebook, graph paper, punched card, photographic paper
Types, thickness and weight
The thickness of paper is often measured by caliper, which is typically given in thousandths of an inch in the United States and in micrometres (µm) in the rest of the world. Paper may be between 0.07 and 0.18 millimetres (0.0028 and 0.0071 in) thick.
Paper is often characterized by weight. In the United States, the weight is the …
Paper stability
Much of the early paper made from wood pulp contained significant amounts of alum, a variety of aluminium sulfate salt that is significantly acidic. Alum was added to paper to assist in sizing, making it somewhat water resistant so that inks did not "run" or spread uncontrollably. Early papermakers did not realize that the alum they added liberally to cure almost every problem encountered in ma…
Overview
Paper is a thin nonwoven material traditionally made from a combination of milled plant and textile fibres. The first paper-like plant-based writing sheet was papyrus in Egypt (4th Century BC), but the first true paper, the first true papermaking process was documented in China during the Eastern Han period (25–220 AD), traditionally attributed to the court official Cai Lun. This plant-puree conglomerate produced by pulp mills and paper mills was used for writing, drawing, and mo…
Precursors
The word "paper" is etymologically derived from papyrus, Ancient Greek for the Cyperus papyrus plant. Papyrus is a thick, paper-like material produced from the pith of the Cyperus papyrus plant which was used in ancient Egypt and other Mediterranean societies for writing long before paper was used in China.
Papyrus is prepared by cutting off thin ribbon-like strips of the interior of the C…
Paper in China
Archaeological evidence of papermaking predates the traditional attribution given to Cai Lun, an imperial eunuch official of the Han dynasty (202 BCE – 220 CE), thus the exact date or inventor of paper cannot be deduced. The earliest extant paper fragment was unearthed at Fangmatan in Gansu province, and was likely part of a map, dated to 179–141 BCE. Fragments of paper have also bee…
Paper in Asia
After its origin in central China, the production and use of paper spread steadily. It is clear that paper was used at Dunhuang by 150 CE, in Loulan in the modern-day province of Xinjiang by 200, and in Turpan by 399. Paper was concurrently introduced in Japan sometime between the years 280 and 610.
Paper spread to Vietnam in the 3rd century, to Korea in the 4th century, and to …
Paper in Europe
The oldest known paper document in Europe is the Mozarab Missal of Silos from the 11th century, probably using paper made in the Islamic part of the Iberian Peninsula. They used hemp and linen rags as a source of fiber. The first recorded paper mill in the Iberian Peninsula was in Xàtiva in 1056. Papermaking reached Europe as early as 1085 in Toledo and was firmly established in Xàtiva, Spain by …
Americas
In the Americas, archaeological evidence indicates that a similar bark-paper writing material was used by the Maya no later than the 5th century CE. Called amatl or amate, it was in widespread use among Mesoamerican cultures until the Spanish conquest. The earliest sample of amate was found at Huitzilapa near the Magdalena Municipality, Jalisco, Mexico, belonging to the shaft tomb cult…
Paper mills
The use of human and animal powered mills was known to Chinese and Muslim papermakers. However, the evidence for water-powered paper mills is elusive among both prior to the 11th century. Scholars have identified paper mills, likely human or animal powered, in Abbasid-era Baghdad during 794–795. It is evident that throughout the Islamic lands e.g. Iran, Syria (Hama and Damascus), and N…
Fiber sources
Before the industrialisation of the paper production the most common fibre source was recycled fibres from used textiles, called rags. The rags were from hemp, linen and cotton. It was not until the introduction of wood pulp in 1843 that paper production was not dependent on recycled materials from ragpickers. It was not realized at the time how unstable wood pulp paper is.
A means of removing printing inks from paper, allowing it to be re-used, was invented by Germa…