Paper

context: Paper is a thin material produced by pressing together moist fibres of cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets. It is a versatile material with many uses, including writing, printing, packaging, cleaning, and a number of industrial and construction processes.
qas: answers: text: wood
question: What is a source for the particles in paper?

answers: text: writing
question: What is a common use for paper?

answers: text: drying
question: What is the last step in paper production?

context: The pulp papermaking process is said to have been developed in China during the early 2nd century AD, possibly as early as the year 105 A.D., by the Han court eunuch Cai Lun, although the earliest archaeological fragments of paper derive from the 2nd century BC in China. The modern pulp and paper industry is global, with China leading its production and the United States right behind it.
qas: answers: text: 2nd century AD
question: When was the pulp papermaking process developed?

answers: text: China
question: What country was the process developed in?

answers: text: China
question: What country is leading in production of paper?

answers: text: United States
question: What country is the second largest produced of paper?

answers: text: Cai Lun
question: Which court eunuch was associated with the papermaking process?

context: The oldest known archaeological fragments of the immediate precursor to modern paper, date to the 2nd century BC in China. The pulp papermaking process is ascribed to Cai Lun, a 2nd-century AD Han court eunuch. With paper as an effective substitute for silk in many applications, China could export silk in greater quantity, contributing to a Golden Age.
qas: answers: text: Cai Lun
question: Who is credited with the papermaking process?

answers: text: silk
question: What material did paper replace upon its invention?

answers: text: Golden Age
question: Which Age did the invention of the papermaking process contribute towards?

answers: text: 2nd
question: What century is the first papermaking process attributed to?

context: Its knowledge and uses spread from China through the Middle East to medieval Europe in the 13th century, where the first water powered paper mills were built. Because of paper's introduction to the West through the city of Baghdad, it was first called bagdatikos. In the 19th century, industrial manufacture greatly lowered its cost, enabling mass exchange of information and contributing to significant cultural shifts. In 1844, the Canadian inventor Charles Fenerty and the German F. G. Keller independently developed processes for pulping wood fibres.
qas: answers: text: 13th
question: In what century did the papermaking process spread from China to Europe?

answers: text: Baghdad
question: Which middle eastern city did the papermaking process to Europe from?

answers: text: bagdatikos
question: What name did the process take on in Baghdad?

answers: text: 19th
question: In which century did the process become much cheaper than before?

answers: text: Charles Fenerty
question: Which Canadian inventor helped F.G. Keller to develop their own process?

context: The word "paper" is etymologically derived from Latin papyrus, which comes from the Greek πάπυρος (papuros), 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 into the Middle East and Europe. Although the word paper is etymologically derived from papyrus, the two are produced very differently and the development of the first is distinct from the development of the second. Papyrus is a lamination of natural plant fibres, while paper is manufactured from fibres whose properties have been changed by maceration.
qas: answers: text: Papyrus
question: What Latin word is paper derived from?

answers: text: Greek
question: What language is papyrus derived from?

answers: text: maceration
question: What process changes the properties of the fibres used in papermaking?

answers: text: Cyperus
question: What plant was used in Egypt to make papyrus?

answers: text: the pith
question: What part of the Cyperus plant was used in making papyrus?

context: To make pulp from wood, a chemical pulping process separates lignin from cellulose fibres. This is accomplished by dissolving lignin in a cooking liquor, so that it may be 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.
qas: answers: text: lignin
question: What is separated from the cellulose fibres?

answers: text: wood-free
question: What type of paper is paper made from chemical pulps known as?

answers: text: 5%
question: What percentage of fibres are wasted in the bleaching process?

answers: text: 90%
question: What percentage of cotton is cellulose?

context: There are three main chemical pulping processes: the sulfite process dates back to the 1840s and it was the dominant method extent before the second world war. The kraft process, invented in the 1870s and first used in the 1890s, is now the most commonly practiced strategy, one of its advantages is the chemical reaction with lignin, that produces heat, which can be used to run a generator. Most pulping operations using the kraft process are net contributors to the electricity grid or use the electricity to run an adjacent paper mill. Another advantage is that this process recovers and reuses all inorganic chemical reagents. Soda pulping is another specialty process used to pulp straws, bagasse and hardwoods with high silicate content.
qas: answers: text: three
question: How many chemical pulping processes are there?

answers: text: 1840s
question: What decade does the sulfite process date to?

answers: text: The kraft process
question: What process is most commonly used?

answers: text: Soda pulping
question: What is another process used to pulp straws with high silicate content?

context: There are two major mechanical pulps, the thermomechanical one (TMP) and groundwood pulp (GW). In the TMP process, wood is chipped and then fed into large steam heated refiners, where the chips are squeezed and converted to fibres between two steel discs. In the groundwood process, debarked logs are fed into grinders where they are pressed against rotating stones to be made into fibres. Mechanical pulping does not remove the lignin, so the yield is very high, >95%, however it causes the paper thus produced to turn yellow and become brittle over time. Mechanical pulps have rather short fibres, thus producing weak paper. Although large amounts of electrical energy are required to produce mechanical pulp, it costs less than the chemical kind.
qas: answers: text: groundwood pulp
question: Besides the thermomechanical process, what is a process used in pulping?

answers: text: debarked logs
question: What is the main ingredient in the groundwood process?

answers: text: weak
question: What strength of paper is produced by mechanical pulps?

context: Recycled papers can be made from 100% recycled materials or blended with virgin pulp, although they are (generally) not as strong nor as bright as papers made from the latter.
qas: answers: text: virgin
question: Recylced papers can be made with what new type of pulp?

context: Besides the fibres, pulps may contain fillers such as chalk or china clay, which improve its characteristics for printing or writing. Additives for sizing purposes may be mixed with it and/or applied to the paper web later in the manufacturing process; the purpose of such sizing is to establish the correct level of surface absorbency to suit ink or paint.
qas: answers: text: china clay
question: What type of clay improves the characteristics of the pulps used in papermaking?

answers: text: Additives
question: What is added for sizing purposes?

answers: text: chalk
question: What besides china clay is used as a filler?

context: Pressing the sheet removes the water by force; once the water is forced from the sheet, a special kind of felt, which is not to be confused with the traditional one, is used to collect the water; whereas when making paper by hand, a blotter sheet is used instead.
qas: answers: text: Pressing
question: How is the water removed by force from a sheet of paper?

answers: text: felt
question: What is used to collect the water expelled from pressing?

answers: text: blotter sheet
question: What is used to collect water when hand-making paper?

answers: text: felt
question: Besides a blotter sheet, what can be used to collect water?

context: Drying involves using air and/or heat to remove water from the paper sheets; in the earliest days of paper making 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. These can reach temperatures above 200 °F (93 °C) and are used in long sequences of more than 40 cans; where the heat produced by these can easily dry the paper to less than 6% moisture.
qas: answers: text: air
question: What is the main component of drying the paper?

answers: text: 6
question: At what percentage moisture content is the papermaking process trying to achieve in the end?

context: Paper at this point is uncoated. Coated paper has a thin layer of material such as calcium carbonate or china clay applied to one or both sides in order to create a surface more suitable for high-resolution halftone screens. (Uncoated papers are rarely suitable for screens above 150 lpi.) Coated or uncoated papers may have their surfaces polished by calendering. Coated papers are divided into matte, semi-matte or silk, and gloss. Gloss papers give the highest optical density in the printed image.
qas: answers: text: china clay
question: Besides calcium, coated paper has a thin layer of what?

answers: text: calendering
question: What process is done to polish the surface of the paper?

answers: text: Gloss
question: What is the shiniest type of coated paper?

answers: text: Gloss
question: What papers give the best optical density?

context: The paper is then fed onto reels if it is to be used on web printing presses, or cut into sheets for other printing processes or other purposes. The fibres in the paper basically run in the machine direction. Sheets are usually cut "long-grain", i.e. with the grain parallel to the longer dimension of the sheet.
qas: answers: text: reels
question: What contraption is used to carry the paper to the web printing presses?

answers: text: long-grain
question: In what manner are sheets normally cut?

answers: text: cut into sheets
question: If the paper is not to be used in the web printing process, what is done?

context: All paper produced by paper machines as the Fourdrinier Machine are wove paper, i.e. the wire mesh that transports the web leaves a pattern that has the same density along the paper grain and across the grain. Textured finishes, watermarks and wire patterns imitating hand-made laid paper can be created by the use of appropriate rollers in the later stages of the machine.
qas: answers: text: wove paper
question: What type of paper is produced on a machine like the Fourdrinier?

answers: text: rollers
question: What is used to apply watermarks and other patterns?

answers: text: density
question: What is in common with the lentgh along and across the grain of paper produced by a machine such as the Fourdrinier?

answers: text: wire mesh
question: What leaves a pattern on the paper that has a consistent density width and lengthwise?

context: Wove paper does not exhibit "laidlines", which are small regular lines left behind on paper when it was handmade in a mould made from rows of metal wires or bamboo. Laidlines are very close together. They run perpendicular to the "chainlines", which are further apart. Handmade paper similarly exhibits "deckle edges", or rough and feathery borders.
qas: answers: text: Laidlines
question: What type of lines does wove paper not exhibit?

answers: text: Laidlines
question: What are small regular lines left on paper when handmade in a mould?

answers: text: chainlines
question: What runs perpendicular to the laidlines?

answers: text: Laidlines
question: Which is lines are commonly higher in density, laidlines or chainlines?

context: The thickness of paper is often measured by caliper, which is typically given in thousandths of an inch in the United States and in thousandths of a mm in the rest of the world. Paper may be between 0.07 and 0.18 millimetres (0.0028 and 0.0071 in) thick.
qas: answers: text: caliper
question: What tool is often used in measuring the thickness of paper?

answers: text: thousandths of an inch
question: In the United States, what units are used when stating the measurements of paper thickness?

answers: text: mm
question: Someone measuring the thickness of paper in the UK is likely to use what unit?

answers: text: 0.0028 and 0.0071 in
question: Sated in inches, what is the common range of paper thickness?

context: Paper is often characterized by weight. In the United States, the weight assigned to a paper is the weight of a ream, 500 sheets, of varying "basic sizes", before the paper is cut into the size it is sold to end customers. For example, a ream of 20 lb, 8.5 in × 11 in (216 mm × 279 mm) paper weighs 5 pounds, because it has been cut from a larger sheet into four pieces. In the United States, printing paper is generally 20 lb, 24 lb, or 32 lb at most. Cover stock is generally 68 lb, and 110 lb or more is considered card stock.
qas: answers: text: weight
question: What characteristic is paper usually classified by?

answers: text: a ream
question: In the US, the weight of what is used to classify paper for sale?

answers: text: card
question: Paper rated at over 110lb is considered what type of stock?

context: In Europe, and other regions using the ISO 216 paper sizing system, the weight is expressed in grammes per square metre (g/m2 or usually just g) of the paper. Printing paper is generally between 60 g and 120 g. Anything heavier than 160 g is considered card. The weight of a ream therefore depends on the dimensions of the paper and its thickness.
qas: answers: text: ISO 216
question: What ISO sizing system does Europe use?

answers: text: card
question: If paper is over 160g what is it considered as?

answers: text: dimensions
question: Besides thickness, what attribute is used in stating the weight of a ream in Europe?

context: Most commercial paper sold in North America is cut to standard paper sizes based on customary units and is defined by the length and width of a sheet of paper.
qas: answers: text: length and width
question: Commercial paper is commonly defined by what?

answers: text: standard paper sizes
question: Most commercial paper in North America is cut in what manner?

answers: text: length and width
question: Standard paper sizes are usually described with what terms?

context: The ISO 216 system used in most other countries is based on the surface area of a sheet of paper, not on a sheet's width and length. It was first adopted in Germany in 1922 and generally spread as nations adopted the metric system. The largest standard size paper is A0 (A zero), measuring one square meter (approx. 1189 × 841 mm). Two sheets of A1, placed upright side by side fit exactly into one sheet of A0 laid on its side. Similarly, two sheets of A2 fit into one sheet of A1 and so forth. Common sizes used in the office and the home are A4 and A3 (A3 is the size of two A4 sheets).
qas: answers: text: ISO 216
question: Most countries besides the US use what ISO System?

answers: text: Germany
question: What country first adopted the ISO 216 standard?

answers: text: A0
question: What is the largest standard size paper?

answers: text: 2
question: How many sheets of A1 paper would cover one single piece of A0 paper?

answers: text: A3
question: What is the lowest numbered A paper that is commonly used at home?

context: The density of paper ranges from 250 kg/m3 (16 lb/cu ft) for tissue paper to 1,500 kg/m3 (94 lb/cu ft) for some speciality paper. Printing paper is about 800 kg/m3 (50 lb/cu ft).
qas: answers: text: tissue paper
question: What is the lightest density of paper produced?

answers: text: 800 kg/m3
question: What is the common density of printing paper?

context: Much of the early paper made from wood pulp contained significant amounts of alum, a variety of aluminium sulfate salts 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 making their product would eventually be detrimental. The cellulose fibres that make up paper are hydrolyzed by acid, and the presence of alum would eventually degrade the fibres until the paper disintegrated in a process that has come to be known as "slow fire". Documents written on rag paper were 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.
qas: answers: text: Alum
question: What acidic salts were commonly found in the early types of paper produced?

answers: text: sizing
question: Early papermakers added alum to help in what process?

answers: text: more stable
question: How was rag paper superior to the early types of paper made using alum?

context: 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.
qas: answers: text: lignin
question: What particle is associated with the yellowing of newspapers?

answers: text: lignin
question: A book is likely made with paper that has low amounts of what component of wood?

answers: text: light and oxygen
question: What does lignin react to to produce the yellowing you see in newspapers?

context: Paper made from wood pulp is not necessarily less durable than a rag paper. The ageing behavior of a paper is determined by its manufacture, not the original source of the fibres. Furthermore, tests sponsored by the Library of Congress prove that all paper is at risk of acid decay, because cellulose itself produces formic, acetic, lactic and oxalic acids.
qas: answers: text: Library of Congress
question: Who sponsored the tests that show that all papers are subject to acid decay?

answers: text: oxalic
question: Besides formic, acetic, and lactic acid, what type of acid does cellulose produce?

context: Mechanical pulping yields almost a tonne of pulp per tonne of dry wood used, which is why mechanical pulps are sometimes referred to as "high yield" pulps. With almost twice the yield as chemical pulping, mechanical pulps is often cheaper. Mass-market paperback books and newspapers tend to use mechanical papers. Book publishers tend to use acid-free paper, made from fully bleached chemical pulps for hardback and trade paperback books.
qas: answers: text: twice
question: How many times more yield does the mechanical pulping process produce when compared to to the chemical pulping process?

answers: text: Mechanical
question: What type of process is used to produce most paper used in paperback books?

answers: text: acid-free
question: What level of acid is usually found in the paper used by book publishers?

context: Worldwide consumption of paper has risen by 400% in the past 40 years leading to increase in deforestation, with 35% of harvested trees being used for paper manufacture. Most paper companies also plant trees to help regrow forests. Logging of old growth forests accounts for less than 10% of wood pulp, but is one of the most controversial issues.
qas: answers: text: 400%
question: In the last 40 years, how much has worldwide paper consumption risen?

answers: text: 35%
question: What percentage of harvested trees are used in the manufacturing of paper?

answers: text: plant trees
question: What do many paper companies do to ensure the health of forests?

answers: text: 10%
question: What percentage of wood pulp comes from old-growth trees?

context: Paper waste accounts for up to 40% of total waste produced in the United States each year, which adds up to 71.6 million tons of paper waste per year in the United States alone. The average office worker in the US prints 31 pages every day. Americans also use on the order of 16 billion paper cups per year.
qas: answers: text: 40%
question: What percentage of total waste can be attributed to paper?

answers: text: 71.6 million
question: How many millions of tons of paper are wasted in the US each year?

answers: text: 16 billion
question: How many paper cups are used by Americans each year?

answers: text: 31
question: How many pages are printed by the average office worker in the US each day?

context: Conventional bleaching of wood pulp using elemental chlorine produces and releases into the environment large amounts of chlorinated organic compounds, including chlorinated dioxins. Dioxins are recognized as a persistent environmental pollutant, regulated internationally by the Stockholm Convention on Persistent Organic Pollutants. Dioxins are highly toxic, and health effects on humans include reproductive, developmental, immune and hormonal problems. They are known to be carcinogenic. Over 90% of human exposure is through food, primarily meat, dairy, fish and shellfish, as dioxins accumulate in the food chain in the fatty tissue of animals.
qas: answers: text: bleaching
question: What process of papermaking is most heavily linked to the pollution?

answers: text: through food
question: How are humans commonly exposed to the byproducts of the bleaching process?

answers: text: fatty tissue
question: Where are dioxins stored in our animal sources of food?

answers: text: the Stockholm Convention on Persistent Organic Pollutants
question: What agency internationally regulates dioxins?

context: Some manufacturers have started using a new, significantly more environmentally friendly alternative to expanded plastic packaging. Made out of paper, and known commercially as paperfoam, the new packaging has very similar mechanical properties to some expanded plastic packaging, but is biodegradable and can also be recycled with ordinary paper.
qas: answers: text: paperfoam
question: What product used in the sale ofpaper is newly used by manufacturers in an effort to be more environmentally friendly?

answers: text: biodegradable
question: What is the main benefit of using paperfoam over traditional shrink-wrap?

answers: text: paper
question: What is paperfoam primarily made of?

answers: text: recycled
question: How is paperfoam commonly disposed of?

context: With increasing environmental concerns about synthetic coatings (such as PFOA) and the higher prices of hydrocarbon based petrochemicals, there is a focus on zein (corn protein) as a coating for paper in high grease applications such as popcorn bags.
qas: answers: text: corn protein
question: What is newly used as a coating in high grease applications?

answers: text: corn protein
question: Popcorn bags produced modernly are likely to use what type of coating?

answers: text: synthetic
question: PFOA is what type of coating?