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What is cellulose primarily made of?
What is cellulose primarily made of?
Natural cellulose fibers lose strength when wet.
Natural cellulose fibers lose strength when wet.
False
What are the two main groups of trees considered in papermaking?
What are the two main groups of trees considered in papermaking?
Softwoods and hardwoods
Cellulose fibers contribute strength to paper, while the shorter fibers primarily contribute to _____ and surface smoothness.
Cellulose fibers contribute strength to paper, while the shorter fibers primarily contribute to _____ and surface smoothness.
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Match the following tree types with their characteristics:
Match the following tree types with their characteristics:
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Which of the following statements about cellulose is true?
Which of the following statements about cellulose is true?
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Wood is the predominant source of papermaking fiber.
Wood is the predominant source of papermaking fiber.
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What preferred species were used during the early pulp industry when the sulfite process was common?
What preferred species were used during the early pulp industry when the sulfite process was common?
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Who created the first sheet of paper around AD 105?
Who created the first sheet of paper around AD 105?
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Papyrus was the least used writing material in ancient times.
Papyrus was the least used writing material in ancient times.
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What materials were used to create the first sheets of paper?
What materials were used to create the first sheets of paper?
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The art of papermaking reached Samarkand in the year _____ .
The art of papermaking reached Samarkand in the year _____ .
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What is the primary purpose of the rail yard and dock mentioned in the passage?
What is the primary purpose of the rail yard and dock mentioned in the passage?
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Match the following events with their respective dates:
Match the following events with their respective dates:
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What was a significant issue faced by paper mills in the 18th century?
What was a significant issue faced by paper mills in the 18th century?
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Mechanical pulp is made by treating wood chips with chemical solutions.
Mechanical pulp is made by treating wood chips with chemical solutions.
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What is the kraft process used for in pulp preparation?
What is the kraft process used for in pulp preparation?
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The papermaking process has changed significantly since the 18th century.
The papermaking process has changed significantly since the 18th century.
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What was the primary raw material used for papermaking before the need for alternatives?
What was the primary raw material used for papermaking before the need for alternatives?
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The pulp that is purified by bleaching and alkaline extraction is known as ______ pulp.
The pulp that is purified by bleaching and alkaline extraction is known as ______ pulp.
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Which of the following products is NOT made from market pulp or paper?
Which of the following products is NOT made from market pulp or paper?
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Match the type of pulp to its main characteristic:
Match the type of pulp to its main characteristic:
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Separate converting operations are usually distant from consumer markets.
Separate converting operations are usually distant from consumer markets.
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The processes for preparing pulp include ______, chemical, and semi-chemical methods.
The processes for preparing pulp include ______, chemical, and semi-chemical methods.
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What is the primary role of alum in paper production?
What is the primary role of alum in paper production?
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Calcium carbonate can be used in paper systems containing alum.
Calcium carbonate can be used in paper systems containing alum.
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Name one common pigment used to enhance the brightness of paper.
Name one common pigment used to enhance the brightness of paper.
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Titanium dioxide is prepared from the minerals ______ and ______.
Titanium dioxide is prepared from the minerals ______ and ______.
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Which of the following is NOT a commonly used filler for paper?
Which of the following is NOT a commonly used filler for paper?
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Match the following pigments to their key characteristics:
Match the following pigments to their key characteristics:
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The amount of filler used in paper production typically ranges from 10% to 20% of the fiber.
The amount of filler used in paper production typically ranges from 10% to 20% of the fiber.
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What is the main purpose of adding an agent like alum when using fillers in paper?
What is the main purpose of adding an agent like alum when using fillers in paper?
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What is the primary chemical used in the Kraft pulping process?
What is the primary chemical used in the Kraft pulping process?
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The Kraft pulping process results in a pulp yield of about 50 percent.
The Kraft pulping process results in a pulp yield of about 50 percent.
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What is the approximate energy requirement to produce one ton of pulp in the Kraft process?
What is the approximate energy requirement to produce one ton of pulp in the Kraft process?
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The pulping chemicals are regenerated in the ______ process.
The pulping chemicals are regenerated in the ______ process.
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What is the main reason that the Kraft bleaching process does not typically allow for effluent recycling?
What is the main reason that the Kraft bleaching process does not typically allow for effluent recycling?
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Total chlorine free (TCF) bleaching sequences are more common than elemental chlorine free (ECF) sequences in the United States.
Total chlorine free (TCF) bleaching sequences are more common than elemental chlorine free (ECF) sequences in the United States.
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What type of sequences is the recent 'cluster rule' expected to standardize in the coming decade?
What type of sequences is the recent 'cluster rule' expected to standardize in the coming decade?
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Match the following energy outputs to their sources in the Kraft process:
Match the following energy outputs to their sources in the Kraft process:
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Study Notes
Papyrus
- Papyrus, a widely used writing material in ancient times, was made from the glue-like sap of a plant.
- The sap acted as an adhesive, cementing layers together to create sheets.
- Unlike modern papermaking, papyrus sheets did not undergo complete defibring.
Papermaking History
- Papermaking can be traced back to AD 105 when Ts'ai Lun, a Chinese official, created paper using mulberry, bast fibres, fishnets, rags, and hemp waste.
- The art of papermaking spread westward, reaching Samarkand in 751 and Baghdad in 793.
- The golden age of Islamic culture facilitated the spread of this technology to Europe.
- By the 14th century, numerous paper mills existed in Europe, particularly in Spain, Italy, France, and Germany.
- The invention of printing in the 1450s significantly increased the demand for paper.
- For centuries, the papermaking process remained largely unchanged, relying on linen and cotton rags as the primary source of material.
- The increasing demand for paper led to shortages, prompting a search for more abundant materials.
Raw Materials
- All plant cell walls contain cellulose fibers, a linear polysaccharide essential for papermaking.
- Cellulose fibers comprise about one-third of annual plant structure and one-half of perennial plant structure.
- These fibres are known for their high strength, durability, and ability to absorb water without losing strength.
- Most plant materials also contain non-fibrous cells that are less desirable for papermaking but are valuable for filling the sheet.
- Wood is the predominant source of papermaking fiber, as it contains a high concentration of fibers and minimal non-fibrous elements.
Wood Pulp
- Forest trees are categorized into two groups: coniferous trees (softwoods) and deciduous trees (hardwoods).
- Softwood fibers are longer (2 to 4 mm), contributing strength to paper.
- Hardwood fibers are shorter (0.5 to 1.5 mm), providing opacity and a smooth surface.
- In the early days of the pulp industry, spruce and fir were the preferred species for pulping.
Pulp Preparation
- Mechanical or groundwood pulp: Produced by grinding wood against a revolving stone or passing chips through a mill, separating and fragmenting fibers.
- Chemical wood pulp: Made by cooking wood chips with chemical solutions in digesters under pressure and high temperatures, dissolving lignin and isolating fibers.
- Semi-chemical pulp: Produced by softening lignin with sulfite or alkali, but not completely dissolving it, before defibring.
- Alpha or dissolving pulp: High-purity chemical wood pulp bleached and extracted, used for specialty papers, rayon, cellulose film, and derivatives.
Kraft Pulping Process
- Wood chips are treated with sodium hydroxide and sodium sulfide under heat and pressure to break down lignin and separate fibers.
- The Kraft process is energy-intensive, requiring 9,000 MJ to produce a ton of pulp, with a pulp yield of about 50%.
- Chemical and energy recovery are efficient in this process, with over 98% of chemicals regenerated.
- The remaining organic matter is burned in a recovery furnace, generating energy to run the mill and often surplus electricity.
- Kraft pulp can be bleached using oxygen, chlorine dioxide, and peroxide.
- Total chlorine free (TCF) sequences are less common than elemental chlorine free (ECF) sequences, which rely on peroxide and ozone.
- Bleach effluent cannot be recycled due to salt buildup, accounting for half the effluent from the Kraft mill.
- The total water use in a Kraft mill is approximately 20,000 gallons per ton of pulp.
Sizing and Filling
- Paper for writing or printing typically contains white pigments or fillers for brightness, opacity, smoothness, and ink receptivity.
- Common fillers include clay (kaolin), titanium dioxide (TiO2), and calcium carbonate (CaCO3).
- Titanium dioxide is the most expensive pigment and often used in mixtures.
- Calcium carbonate is preferred for its brightness, opacity, ink receptivity, and burning properties in cigarette paper.
- Other fillers include zinc oxide, zinc sulfide, hydrated silica, calcium sulfate, hydrated alumina, talc, barium sulfate, and asbestos.
- Fillers are often used in paper coatings.
- Alum is used as an agent to bond fillers to fibers. Filler content can vary from 1 to 10% of the fiber.
- Soluble dyes or colored pigments are added to the paper stock to impart colour.
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Description
Explore the ancient origins of papyrus and the evolution of papermaking from its inception in China to its spread across the world. This quiz covers significant milestones in the history of writing materials, including the innovations of Ts'ai Lun and the impact of Islamic culture on papermaking in Europe. Test your knowledge on how these developments shaped communication through the ages.
