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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 layers of wood fiber - listed from innermost to outermost?
Lumen - S3 Wall - S2 Wall - S1 Wall - P Wall - and middle lamela.
Even stock spread - Level out cross currents and consistency variations level out MD velocity gradients - even flow - disperse flocs
Chemi- thermo- mechanical pulping.
Costly - weak product - mechanical damage to fibers - hornification.

2. What is common filler?
Help retain fines and fillers.
Newsprint - some Printing and writing - and coated publications.
Calcium carbonate.
Corrugating Medium alone.

3. What two ways is kraft pulping performed?
High quality - adaptable - and simple.
365 million metric tons
batch and continuous.
Kymene.

4. What percent of Paper and Board in the US is PRODUCED from RECYCLING?
25%
37%
Low yield - high chemical dosage required - high capital cost - requirement of recovery system - and darkens pulp.
365 million metric tons

5. Advantages of recycled pulping?
To deliver stock on to the wire.
Produced in digester - separated with blow tank.
simple - no pulping required other than hyrdapulper.
Poor bonding - yellow coloration - high energy costs.

6. What are some products of Recycled Pulping?
Corrugating medium - newsprint - some printing and writing grades.
Mechanical action to improve paper characteristics - such as strength.
To enable paper to RESIST liquid penetration.
85 million metric tons

7. What are some disadvantages of Chemical pulping?
To deliver stock on to the wire.
To improve brightness.
1) Fourdriner 2) Top-Wire former 3) Gap former
Low yield - high chemical dosage required - high capital cost - requirement of recovery system - and darkens pulp.

8. Name the primary purpose of the headbox.
High yield - low cost - simple.
To deliver stock on to the wire.
Percent ISO.
37%

9. What percentage of the average P&W sheet is Softwood?
Percent ISO.
25%
Even distribution of fibers; little flocs - blobs or clumps; no barring or streaking in either the MD or CD.
Corrugating medium - newsprint - some printing and writing grades.

10. What is the PRIMARY goal of pulping processes?
Liberation of Fibers.
The amount of residual lignin in pulp after cooking.
Totally Chlorine Free.
37%

11. What is brownstock?
Brown pulp that is unbleached.
Cellulose (50%) - Hemicellulose (25%) - and Lignin (25%).
Mild chemical charge with chips - disk refine.
Liberation of Fibers.

12. List the 3 forces of wet end water removal.
Unbleached Kraft
simple - no pulping required other than hyrdapulper.
1) Gravity 2) Vacuum 3) Press
Low yield - high chemical dosage required - high capital cost - requirement of recovery system - and darkens pulp.

13. What is Effective Alkali?
(NaOH + half of Na2S)/OD fiber expressed as Na2O
A web of cellulose fibers deposited from water suspension to form Hydrogen bonds.
Kymene.
1) Fourdriner 2) Top-Wire former 3) Gap former

14. Where is black liquor produced and how is it seperated from the pulp?
1) Evaptoration of Black Liquor 2) Incineration 3) Causticizing and Calcining
Chemi- thermo- mechanical pulping.
Produced in digester - separated with blow tank.
Hydrapulping - remove debris - maintain fibers.

15. What is the function of Heartwood and Sapwood?
Stone ground wood.
Newsprint - some Printing and writing - and coated publications.
(NaOH + Na2S)/OD fiber expressed as Na2O
Conduction.

16. What is formation?
Soda (NaOH) - Sulfite (SO2) - and Kraft (NaOH + Na2S).
Costly - weak product - mechanical damage to fibers - hornification.
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 are the three big steps to Chemical recovery?
Produced in digester - separated with blow tank.
1) Evaptoration of Black Liquor 2) Incineration 3) Causticizing and Calcining
Brown pulp that is unbleached.
Water - dissolved cellulose - hemicellulose - and lignin - and chemicals.

18. Define Market Pulp.
Starch.
Paper pulp sold on the open market for repulping.
Soda (NaOH) - Sulfite (SO2) - and Kraft (NaOH + Na2S).
Springwood.

19. What is the purpose of sizing additives?
Thermomechanical pulping
To enable paper to RESIST liquid penetration.
simple - no pulping required other than hyrdapulper.
Unbleached Kraft

20. What is the largest paperboard grade in the US by weight?
Calcium carbonate.
Unbleached Kraft
ASA and AKD for Alkaline paper or Rosin and Alum for Acid Linerboard.
Improve optical and physical properties of the sheet.

21. What are the jobs of the Recovery Boiler?
Corrugating Medium alone.
Burn strong black liquor - Convert heat to steam - Turn chemicals into smelt - Recover inorganics as Na2S and Na2CO3
Na2S/(NaOH + Na2S) expressed as a percent NaO
Linerboard - Printing and writing paper - Food board - dissolving pulp.

22. Disadvantages of recycled pulping?
(NaOH + half of Na2S)/OD fiber expressed as Na2O
Costly - weak product - mechanical damage to fibers - hornification.
Even distribution of fibers; little flocs - blobs or clumps; no barring or streaking in either the MD or CD.
Corrugating Medium alone.

23. Define refining.
Kymene.
Mechanical action to improve paper characteristics - such as strength.
57%
6 to 7 times.

24. What do the stages in DEDED do?
D1: attack lignin E1: solubilize attacked lignin D2: break up lignin - start brightening E2: dissolve more lignin D3: attack chromophores - achieve final brightness
Linerboard - Printing and writing paper - Food board - dissolving pulp.
655 and 98 lbs/year
High yield - low cost - simple.

25. What are the steps to recycled pulping?
Pressurized ground wood.
Hydrapulping - remove debris - maintain fibers.
batch and continuous.
Treat chips with chemical dosage - heat to high temperature - and wash the chips of black liquor and remaining lignin.

26. What is a common wet strength aid?
Soda (NaOH) - Sulfite (SO2) - and Kraft (NaOH + Na2S).
(NaOH + half of Na2S)/OD fiber expressed as Na2O
Kymene.
Costly chemical recovery - only used for corrugating medium production.

27. What are the steps in Semi-Chemical Pulping?
Corrugating Medium alone.
Low yield - high chemical dosage required - high capital cost - requirement of recovery system - and darkens pulp.
655 and 98 lbs/year
Mild chemical charge with chips - disk refine.

28. What is the single product of Semi- chemical pulping?
655 and 98 lbs/year
Costly - weak product - mechanical damage to fibers - hornification.
Thermomechanical pulping
Corrugating Medium alone.

29. Define Fluff Pulp.
Pulp sold to manufacturers of absorbent products - such as diapers.
Chemi- thermo- mechanical pulping.
The amount of residual lignin in pulp after cooking.
Totally Chlorine Free.

30. What does SGW mean?
To deliver stock on to the wire.
Stone ground wood.
Steam is saved by exposing the strongest - thickest - black liquor to the hottest steam first - in order to evaporate the most water efficiently.
Costly chemical recovery - only used for corrugating medium production.

31. The set up of Evaporators and how it saves steam economy.
Steam is saved by exposing the strongest - thickest - black liquor to the hottest steam first - in order to evaporate the most water efficiently.
Printing and writing.
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
Creates a strong - high quality - sheet that sells for a high price.

32. What are some advantages of Chemical pulping?
Newsprint - some Printing and writing - and coated publications.
Environmentally Chlorine Free.
ASA and AKD for Alkaline paper or Rosin and Alum for Acid Linerboard.
Creates a strong - high quality - sheet that sells for a high price.

33. How much Paper/Board is produced in the US a year?
85 million metric tons
The goal is to remove some lignin between the cell walls - but maintain stiffness.
25%
Totally Chlorine Free.

34. Disadvantages of Mechanical Pulping?
Summerwood.
33% - 55% - and 8%
Poor bonding - yellow coloration - high energy costs.
Steam is saved by exposing the strongest - thickest - black liquor to the hottest steam first - in order to evaporate the most water efficiently.

35. Light rings in wood are known as what?
Burn strong black liquor - Convert heat to steam - Turn chemicals into smelt - Recover inorganics as Na2S and Na2CO3
Springwood.
85 million metric tons
Hydrapulping - remove debris - maintain fibers.

36. What is the H- factor? What does it tell us?
Hydrapulping - remove debris - maintain fibers.
Creates a strong - high quality - sheet that sells for a high price.
57%
Relation of rate to time - also involving temperature. Tells how long to cook chips.

37. List the 3 types of headboxes.
Pulp sold to manufacturers of absorbent products - such as diapers.
1) Open 2) Pressurized 3) Hydraulic
Summerwood.
33% - 55% - and 8%

38. What are the steps in Chemical pulping?
Treat chips with chemical dosage - heat to high temperature - and wash the chips of black liquor and remaining lignin.
25%
Cellulose (50%) - Hemicellulose (25%) - and Lignin (25%).
Even distribution of fibers; little flocs - blobs or clumps; no barring or streaking in either the MD or CD.

39. What percent of Paper and Board in the US is RECOVERED each year?
1) Gravity 2) Vacuum 3) Press
57%
Percent ISO.
batch and continuous.

40. What are the steps of Mechanical Pulping?
Printing and Writing - Board - and Tissue.
High yield - low cost - simple.
Grinding and refining.
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

41. What is world production per year of paper/board?
Produced in digester - separated with blow tank.
Grinding and refining.
365 million metric tons
Liberation of Fibers.

42. What do retention aids do?
Even stock spread - Level out cross currents and consistency variations level out MD velocity gradients - even flow - disperse flocs
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
Help retain fines and fillers.
Costly - weak product - mechanical damage to fibers - hornification.

43. What are some advantages of Semi- chemical pulping?
6 to 7 times.
Cellulose (50%) - Hemicellulose (25%) - and Lignin (25%).
75%
High yield - low cost - simple.

44. When and where was paper invented?
China - 105 AD
Environmentally Chlorine Free.
Linerboard - Printing and writing paper - Food board - dissolving pulp.
Low yield - high chemical dosage required - high capital cost - requirement of recovery system - and darkens pulp.

45. What percent of World production does the US contribute to Paper/Board?
25%
High yield - simple - wood colored pulp - easy bleach - no chemical recovery.
Mechanical action to improve paper characteristics - such as strength.
Burn strong black liquor - Convert heat to steam - Turn chemicals into smelt - Recover inorganics as Na2S and Na2CO3

46. How is brightness measured?
Linerboard and Corrugating medium.
Percent ISO.
Chemi- thermo- mechanical pulping.
Starch.

47. How many times can a fiber be recycled before it is completely destroyed typically?
6 to 7 times.
Mechanical action to improve paper characteristics - such as strength.
Soda (NaOH) - Sulfite (SO2) - and Kraft (NaOH + Na2S).
High yield - low cost - simple.

48. What are some strength additives?
Starch.
To enable paper to RESIST liquid penetration.
Creates a strong - high quality - sheet that sells for a high price.
Na2S/(NaOH + Na2S) expressed as a percent NaO

49. What is the largest paper grade in the US by weight?
Steam is saved by exposing the strongest - thickest - black liquor to the hottest steam first - in order to evaporate the most water efficiently.
Printing and writing.
Even distribution of fibers; little flocs - blobs or clumps; no barring or streaking in either the MD or CD.
Protection.

50. What are the four broad categories of pulping?
37%
Chemical - Semi- chemical - Mechanical - and Recycled.
Percent ISO.
Linerboard - Printing and writing paper - Food board - dissolving pulp.