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Paper Science Engineering Core Concepts

Instructions:

Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What are the 3 main components of wood and what percentage of wood do they make up?
Collapse of ribbons in fibers - Fibrillization of outer surface - Production of fines - reduction of freeness value - Shorter - flexible - fibers are achieved - Burst and tensile strength improve - tear strength goes down
Newsprint - some Printing and writing - and coated publications.
Cellulose (50%) - Hemicellulose (25%) - and Lignin (25%).
Chemical - Semi- chemical - Mechanical - and Recycled.

2. What are the 3 major grades of paper?
Chemi- thermo- mechanical pulping.
Printing and Writing - Board - and Tissue.
Costly chemical recovery - only used for corrugating medium production.
Mechanical action to improve paper characteristics - such as strength.

3. Define refining.
Treat chips with chemical dosage - heat to high temperature - and wash the chips of black liquor and remaining lignin.
(NaOH + half of Na2S)/OD fiber expressed as Na2O
Mechanical action to improve paper characteristics - such as strength.
Costly chemical recovery - only used for corrugating medium production.

4. What are some disadvantages of Semi- chemical pulping?
Cellulose (50%) - Hemicellulose (25%) - and Lignin (25%).
Costly chemical recovery - only used for corrugating medium production.
85 million metric tons
High yield - low cost - simple.

5. What are the layers of wood fiber - listed from innermost to outermost?
High yield - low cost - simple.
Lumen - S3 Wall - S2 Wall - S1 Wall - P Wall - and middle lamela.
33% - 55% - and 8%
Corrugating Medium alone.

6. What is world production per year of paper/board?
365 million metric tons
Starch.
57%
25%

7. Define Paper.
Pulp sold to manufacturers of absorbent products - such as diapers.
A web of cellulose fibers deposited from water suspension to form Hydrogen bonds.
The goal is to remove some lignin between the cell walls - but maintain stiffness.
Chemical - Semi- chemical - Mechanical - and Recycled.

8. What percentage of the average P&W sheet is Hardwood?
75%
Calcium carbonate.
Costly chemical recovery - only used for corrugating medium production.
A web of cellulose fibers deposited from water suspension to form Hydrogen bonds.

9. What does PGW mean?
Pressurized ground wood.
Treat chips with chemical dosage - heat to high temperature - and wash the chips of black liquor and remaining lignin.
(NaOH + half of Na2S)/OD fiber expressed as Na2O
Pulp sold to manufacturers of absorbent products - such as diapers.

10. The set up of Evaporators and how it saves steam economy.
Even distribution of fibers; little flocs - blobs or clumps; no barring or streaking in either the MD or CD.
Chemical - Semi- chemical - Mechanical - and Recycled.
Steam is saved by exposing the strongest - thickest - black liquor to the hottest steam first - in order to evaporate the most water efficiently.
85 million metric tons

11. What are the steps of Mechanical Pulping?
Paper pulp sold on the open market for repulping.
Grinding and refining.
Even distribution of fibers; little flocs - blobs or clumps; no barring or streaking in either the MD or CD.
Thermomechanical pulping

12. What are the steps to recycled pulping?
Corrugating Medium alone.
Even distribution of fibers; little flocs - blobs or clumps; no barring or streaking in either the MD or CD.
Pressurized ground wood.
Hydrapulping - remove debris - maintain fibers.

13. Light rings in wood are known as what?
batch and continuous.
Costly chemical recovery - only used for corrugating medium production.
1) Fourdriner 2) Top-Wire former 3) Gap former
Springwood.

14. What part of wood largely goes into paper?
33% - 55% - and 8%
Environmentally Chlorine Free.
Soda (NaOH) - Sulfite (SO2) - and Kraft (NaOH + Na2S).
The Xylem - or trachea fibers.

15. What is Sulfidity?
Na2S/(NaOH + Na2S) expressed as a percent NaO
To deliver stock on to the wire.
Mild chemical charge with chips - disk refine.
Percent ISO.

16. What are some products of Recycled Pulping?
Grinding and refining.
Steam is saved by exposing the strongest - thickest - black liquor to the hottest steam first - in order to evaporate the most water efficiently.
Corrugating medium - newsprint - some printing and writing grades.
Even distribution of fibers; little flocs - blobs or clumps; no barring or streaking in either the MD or CD.

17. What is brownstock?
Printing and writing.
Poor bonding - yellow coloration - high energy costs.
Brown pulp that is unbleached.
(NaOH + half of Na2S)/OD fiber expressed as Na2O

18. What is the H- factor? What does it tell us?
Relation of rate to time - also involving temperature. Tells how long to cook chips.
The measure of how freely water drains; aka the Drainage rate. Usually measured as Canadian Standard Freeness.
365 million metric tons
To deliver stock on to the wire.

19. What are some strength additives?
D1: attack lignin E1: solubilize attacked lignin D2: break up lignin - start brightening E2: dissolve more lignin D3: attack chromophores - achieve final brightness
6 to 7 times.
Starch.
The amount of residual lignin in pulp after cooking.

20. What is the PRIMARY goal of pulping processes?
Improve optical and physical properties of the sheet.
Help retain fines and fillers.
D1: attack lignin E1: solubilize attacked lignin D2: break up lignin - start brightening E2: dissolve more lignin D3: attack chromophores - achieve final brightness
Liberation of Fibers.

21. Dark rings in wood are known as what?
1) Open 2) Pressurized 3) Hydraulic
Summerwood.
Collapse of ribbons in fibers - Fibrillization of outer surface - Production of fines - reduction of freeness value - Shorter - flexible - fibers are achieved - Burst and tensile strength improve - tear strength goes down
Chemi- thermo- mechanical pulping.

22. What is the single product of Semi- chemical pulping?
Corrugating Medium alone.
Treat chips with chemical dosage - heat to high temperature - and wash the chips of black liquor and remaining lignin.
Linerboard and Corrugating medium.
Na2S/(NaOH + Na2S) expressed as a percent NaO

23. Advantages of Mechanical Pulping?
High yield - simple - wood colored pulp - easy bleach - no chemical recovery.
Mild chemical charge with chips - disk refine.
The Xylem - or trachea fibers.
Produced in digester - separated with blow tank.

24. What does the Kappa number indicate?
The amount of residual lignin in pulp after cooking.
Costly - weak product - mechanical damage to fibers - hornification.
Unbleached Kraft
1) Evaptoration of Black Liquor 2) Incineration 3) Causticizing and Calcining

25. What are the four broad categories of pulping?
Chemical - Semi- chemical - Mechanical - and Recycled.
Thermomechanical pulping
6 to 7 times.
High yield - simple - wood colored pulp - easy bleach - no chemical recovery.

26. What two ways is kraft pulping performed?
To enable paper to RESIST liquid penetration.
1) Gravity 2) Vacuum 3) Press
Liberation of Fibers.
batch and continuous.

27. How much Paper/Board is produced in the US a year?
Help retain fines and fillers.
Creates a strong - high quality - sheet that sells for a high price.
The goal is to remove some lignin between the cell walls - but maintain stiffness.
85 million metric tons

28. What is the purpose of sizing additives?
(NaOH + half of Na2S)/OD fiber expressed as Na2O
Pulp sold to manufacturers of absorbent products - such as diapers.
D1: attack lignin E1: solubilize attacked lignin D2: break up lignin - start brightening E2: dissolve more lignin D3: attack chromophores - achieve final brightness
To enable paper to RESIST liquid penetration.

29. What are the steps in Chemical pulping?
57%
Treat chips with chemical dosage - heat to high temperature - and wash the chips of black liquor and remaining lignin.
1) Gravity 2) Vacuum 3) Press
simple - no pulping required other than hyrdapulper.

30. What are the steps in Semi-Chemical Pulping?
China - 105 AD
Na2S/(NaOH + Na2S) expressed as a percent NaO
Mild chemical charge with chips - disk refine.
37%

31. Name the primary purpose of the headbox.
Corrugating medium - newsprint - some printing and writing grades.
Unbleached Kraft
655 and 98 lbs/year
To deliver stock on to the wire.

32. What are some disadvantages of Chemical pulping?
polyacrylamide.
1) Evaptoration of Black Liquor 2) Incineration 3) Causticizing and Calcining
Low yield - high chemical dosage required - high capital cost - requirement of recovery system - and darkens pulp.
Na2S/(NaOH + Na2S) expressed as a percent NaO

33. What does TCF stand for?
To enable paper to RESIST liquid penetration.
simple - no pulping required other than hyrdapulper.
Totally Chlorine Free.
Kymene.

34. What are some roles of the headbox?
6 to 7 times.
Even stock spread - Level out cross currents and consistency variations level out MD velocity gradients - even flow - disperse flocs
75%
1) Gravity 2) Vacuum 3) Press

35. What is the per capita paper consumption for the US and China - respectively?
Pulp sold to manufacturers of absorbent products - such as diapers.
High quality - adaptable - and simple.
The measure of how freely water drains; aka the Drainage rate. Usually measured as Canadian Standard Freeness.
655 and 98 lbs/year

36. What do the stages in DEDED do?
Water - dissolved cellulose - hemicellulose - and lignin - and chemicals.
Newsprint - some Printing and writing - and coated publications.
D1: attack lignin E1: solubilize attacked lignin D2: break up lignin - start brightening E2: dissolve more lignin D3: attack chromophores - achieve final brightness
Hydrapulping - remove debris - maintain fibers.

37. What are the three big steps to Chemical recovery?
Pulp sold to manufacturers of absorbent products - such as diapers.
Printing and writing.
1) Evaptoration of Black Liquor 2) Incineration 3) Causticizing and Calcining
Pressurized ground wood.

38. What is the primary goal of bleaching?
To improve brightness.
Totally Chlorine Free.
Liberation of Fibers.
Help retain fines and fillers.

39. What is the function of the Cambium?
China - 105 AD
Growth.
To enable paper to RESIST liquid penetration.
High yield - simple - wood colored pulp - easy bleach - no chemical recovery.

40. What are the jobs of the Recovery Boiler?
33% - 55% - and 8%
Kymene.
Burn strong black liquor - Convert heat to steam - Turn chemicals into smelt - Recover inorganics as Na2S and Na2CO3
Relation of rate to time - also involving temperature. Tells how long to cook chips.

41. List the 3 types of Wet end machines.
polyacrylamide.
1) Fourdriner 2) Top-Wire former 3) Gap former
Growth.
Totally Chlorine Free.

42. What does ECF stand for?
Environmentally Chlorine Free.
Even distribution of fibers; little flocs - blobs or clumps; no barring or streaking in either the MD or CD.
Improve optical and physical properties of the sheet.
Even stock spread - Level out cross currents and consistency variations level out MD velocity gradients - even flow - disperse flocs

43. What is Effective Alkali?
(NaOH + half of Na2S)/OD fiber expressed as Na2O
Steam is saved by exposing the strongest - thickest - black liquor to the hottest steam first - in order to evaporate the most water efficiently.
Newsprint - some Printing and writing - and coated publications.
The measure of how freely water drains; aka the Drainage rate. Usually measured as Canadian Standard Freeness.

44. What are some advantages of Semi- chemical pulping?
Burn strong black liquor - Convert heat to steam - Turn chemicals into smelt - Recover inorganics as Na2S and Na2CO3
High yield - low cost - simple.
polyacrylamide.
Thermomechanical pulping

45. What percent of Paper and Board in the US is PRODUCED from RECYCLING?
Even distribution of fibers; little flocs - blobs or clumps; no barring or streaking in either the MD or CD.
37%
Printing and Writing - Board - and Tissue.
Improve optical and physical properties of the sheet.

46. How many times can a fiber be recycled before it is completely destroyed typically?
To improve brightness.
Water - dissolved cellulose - hemicellulose - and lignin - and chemicals.
Soda (NaOH) - Sulfite (SO2) - and Kraft (NaOH + Na2S).
6 to 7 times.

47. What percent of World production does the US contribute to Paper/Board?
High yield - simple - wood colored pulp - easy bleach - no chemical recovery.
25%
85 million metric tons
Corrugating Medium alone.

48. What do fillers do?
Newsprint - some Printing and writing - and coated publications.
Improve optical and physical properties of the sheet.
ASA and AKD for Alkaline paper or Rosin and Alum for Acid Linerboard.
Conduction.

49. Disadvantages of recycled pulping?
Relation of rate to time - also involving temperature. Tells how long to cook chips.
Starch.
Grinding and refining.
Costly - weak product - mechanical damage to fibers - hornification.

50. What is the largest paperboard grade in the US by weight?
Unbleached Kraft
365 million metric tons
Relation of rate to time - also involving temperature. Tells how long to cook chips.
The amount of residual lignin in pulp after cooking.