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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 is a retention additive often used?
Na2S/(NaOH + Na2S) expressed as a percent NaO
Linerboard - Printing and writing paper - Food board - dissolving pulp.
polyacrylamide.
Calcium carbonate.

2. What percent of Paper and Board in the US is RECOVERED each year?
25%
Water - dissolved cellulose - hemicellulose - and lignin - and chemicals.
57%
Grinding and refining.

3. What do the stages in DEDED do?
Low yield - high chemical dosage required - high capital cost - requirement of recovery system - and darkens pulp.
D1: attack lignin E1: solubilize attacked lignin D2: break up lignin - start brightening E2: dissolve more lignin D3: attack chromophores - achieve final brightness
Corrugating Medium alone.
Summerwood.

4. What are the advantages of Kraft pulping?
Kymene.
25%
simple - no pulping required other than hyrdapulper.
High quality - adaptable - and simple.

5. Dark rings in wood are known as what?
Summerwood.
365 million metric tons
Paper pulp sold on the open market for repulping.
Linerboard - Printing and writing paper - Food board - dissolving pulp.

6. What are some products of Recycled Pulping?
batch and continuous.
Corrugating medium - newsprint - some printing and writing grades.
33% - 55% - and 8%
Printing and writing.

7. What do retention aids do?
Starch.
Help retain fines and fillers.
ASA and AKD for Alkaline paper or Rosin and Alum for Acid Linerboard.
75%

8. What are some roles of the headbox?
The goal is to remove some lignin between the cell walls - but maintain stiffness.
Creates a strong - high quality - sheet that sells for a high price.
Corrugating Medium alone.
Even stock spread - Level out cross currents and consistency variations level out MD velocity gradients - even flow - disperse flocs

9. What percent of World production does the US contribute to Paper/Board?
Protection.
Cellulose (50%) - Hemicellulose (25%) - and Lignin (25%).
Even stock spread - Level out cross currents and consistency variations level out MD velocity gradients - even flow - disperse flocs
25%

10. What is the per capita paper consumption for the US and China - respectively?
(NaOH + half of Na2S)/OD fiber expressed as Na2O
Water - dissolved cellulose - hemicellulose - and lignin - and chemicals.
batch and continuous.
655 and 98 lbs/year

11. What is black liquor?
Protection.
Low yield - high chemical dosage required - high capital cost - requirement of recovery system - and darkens pulp.
Pulp sold to manufacturers of absorbent products - such as diapers.
Water - dissolved cellulose - hemicellulose - and lignin - and chemicals.

12. Advantages of Mechanical Pulping?
High yield - simple - wood colored pulp - easy bleach - no chemical recovery.
Linerboard and Corrugating medium.
Soda (NaOH) - Sulfite (SO2) - and Kraft (NaOH + Na2S).
China - 105 AD

13. How many times can a fiber be recycled before it is completely destroyed typically?
Starch.
6 to 7 times.
simple - no pulping required other than hyrdapulper.
Calcium carbonate.

14. What part of wood largely goes into paper?
Thermomechanical pulping
To enable paper to RESIST liquid penetration.
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
The Xylem - or trachea fibers.

15. What sets Semi-Chemical pulping apart from Chemical Pulping?
Thermomechanical pulping
Steam is saved by exposing the strongest - thickest - black liquor to the hottest steam first - in order to evaporate the most water efficiently.
The goal is to remove some lignin between the cell walls - but maintain stiffness.
Printing and writing.

16. What are some disadvantages of Chemical pulping?
China - 105 AD
655 and 98 lbs/year
The measure of how freely water drains; aka the Drainage rate. Usually measured as Canadian Standard Freeness.
Low yield - high chemical dosage required - high capital cost - requirement of recovery system - and darkens pulp.

17. What are some advantages of Chemical pulping?
Lumen - S3 Wall - S2 Wall - S1 Wall - P Wall - and middle lamela.
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
Grinding and refining.
Creates a strong - high quality - sheet that sells for a high price.

18. What percent of Paper and Board in the US is PRODUCED from RECYCLING?
33% - 55% - and 8%
Printing and Writing - Board - and Tissue.
37%
655 and 98 lbs/year

19. List the 3 forces of wet end water removal.
Burn strong black liquor - Convert heat to steam - Turn chemicals into smelt - Recover inorganics as Na2S and Na2CO3
1) Gravity 2) Vacuum 3) Press
Relation of rate to time - also involving temperature. Tells how long to cook chips.
Springwood.

20. Light rings in wood are known as what?
Springwood.
Growth.
Costly - weak product - mechanical damage to fibers - hornification.
The Xylem - or trachea fibers.

21. How is brightness measured?
Thermomechanical pulping
Cellulose (50%) - Hemicellulose (25%) - and Lignin (25%).
Stone ground wood.
Percent ISO.

22. Where is black liquor produced and how is it seperated from the pulp?
The Xylem - or trachea fibers.
57%
(NaOH + half of Na2S)/OD fiber expressed as Na2O
Produced in digester - separated with blow tank.

23. What is the largest paper grade in the US by weight?
Produced in digester - separated with blow tank.
Printing and writing.
The goal is to remove some lignin between the cell walls - but maintain stiffness.
The Xylem - or trachea fibers.

24. What is the PRIMARY goal of pulping processes?
Liberation of Fibers.
1) Evaptoration of Black Liquor 2) Incineration 3) Causticizing and Calcining
Totally Chlorine Free.
simple - no pulping required other than hyrdapulper.

25. What are some strength additives?
Starch.
To deliver stock on to the wire.
Paper pulp sold on the open market for repulping.
Corrugating Medium alone.

26. What are the steps in Chemical pulping?
To deliver stock on to the wire.
Help retain fines and fillers.
25%
Treat chips with chemical dosage - heat to high temperature - and wash the chips of black liquor and remaining lignin.

27. What is Sulfidity?
To deliver stock on to the wire.
High quality - adaptable - and simple.
Na2S/(NaOH + Na2S) expressed as a percent NaO
Summerwood.

28. What are the steps to recycled pulping?
Chemical - Semi- chemical - Mechanical - and Recycled.
Grinding and refining.
Relation of rate to time - also involving temperature. Tells how long to cook chips.
Hydrapulping - remove debris - maintain fibers.

29. What is the largest paperboard grade in the US by weight?
Protection.
The Xylem - or trachea fibers.
Unbleached Kraft
Conduction.

30. What is the purpose of sizing additives?
1) Open 2) Pressurized 3) Hydraulic
1) Fourdriner 2) Top-Wire former 3) Gap former
High yield - low cost - simple.
To enable paper to RESIST liquid penetration.

31. What are the products of Mechanical Pulping?
Creates a strong - high quality - sheet that sells for a high price.
25%
Linerboard and Corrugating medium.
Newsprint - some Printing and writing - and coated publications.

32. Define refining.
To improve brightness.
Lumen - S3 Wall - S2 Wall - S1 Wall - P Wall - and middle lamela.
Mechanical action to improve paper characteristics - such as strength.
Pressurized ground wood.

33. What does the Kappa number indicate?
High yield - simple - wood colored pulp - easy bleach - no chemical recovery.
The amount of residual lignin in pulp after cooking.
25%
Corrugating medium - newsprint - some printing and writing grades.

34. What does CTMP mean?
Chemi- thermo- mechanical pulping.
High yield - low cost - simple.
Protection.
A web of cellulose fibers deposited from water suspension to form Hydrogen bonds.

35. What is formation?
polyacrylamide.
Chemi- thermo- mechanical pulping.
Even distribution of fibers; little flocs - blobs or clumps; no barring or streaking in either the MD or CD.
Conduction.

36. What are some advantages of Semi- chemical pulping?
To improve brightness.
High yield - low cost - simple.
Growth.
To deliver stock on to the wire.

37. What is common filler?
Pressurized ground wood.
Chemical - Semi- chemical - Mechanical - and Recycled.
Calcium carbonate.
China - 105 AD

38. What are the three types of chemical pulping?
1) Gravity 2) Vacuum 3) Press
Soda (NaOH) - Sulfite (SO2) - and Kraft (NaOH + Na2S).
Water - dissolved cellulose - hemicellulose - and lignin - and chemicals.
Calcium carbonate.

39. What are the 3 major grades of paper?
Printing and Writing - Board - and Tissue.
Mechanical action to improve paper characteristics - such as strength.
polyacrylamide.
Environmentally Chlorine Free.

40. What does PGW mean?
25%
simple - no pulping required other than hyrdapulper.
1) Fourdriner 2) Top-Wire former 3) Gap former
Pressurized ground wood.

41. What is the single product of Semi- chemical pulping?
Stone ground wood.
6 to 7 times.
Corrugating Medium alone.
High quality - adaptable - and simple.

42. What is Effective Alkali?
The goal is to remove some lignin between the cell walls - but maintain stiffness.
(NaOH + half of Na2S)/OD fiber expressed as Na2O
ASA and AKD for Alkaline paper or Rosin and Alum for Acid Linerboard.
Newsprint - some Printing and writing - and coated publications.

43. What are some sizing additives?
37%
ASA and AKD for Alkaline paper or Rosin and Alum for Acid Linerboard.
Improve optical and physical properties of the sheet.
33% - 55% - and 8%

44. What are the layers of wood fiber - listed from innermost to outermost?
Costly - weak product - mechanical damage to fibers - hornification.
57%
Lumen - S3 Wall - S2 Wall - S1 Wall - P Wall - and middle lamela.
Water - dissolved cellulose - hemicellulose - and lignin - and chemicals.

45. What are the four broad categories of pulping?
Treat chips with chemical dosage - heat to high temperature - and wash the chips of black liquor and remaining lignin.
Chemical - Semi- chemical - Mechanical - and Recycled.
Conduction.
Mechanical action to improve paper characteristics - such as strength.

46. What are the steps of Mechanical Pulping?
85 million metric tons
The amount of residual lignin in pulp after cooking.
Unbleached Kraft
Grinding and refining.

47. How much Paper/Board is produced in the US a year?
1) Gravity 2) Vacuum 3) Press
Thermomechanical pulping
85 million metric tons
Low yield - high chemical dosage required - high capital cost - requirement of recovery system - and darkens pulp.

48. Disadvantages of Mechanical Pulping?
Liberation of Fibers.
Na2S/(NaOH + Na2S) expressed as a percent NaO
Mild chemical charge with chips - disk refine.
Poor bonding - yellow coloration - high energy costs.

49. What happens during refining?
Growth.
The Xylem - or trachea fibers.
simple - no pulping required other than hyrdapulper.
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

50. Define Paper.
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.
Paper pulp sold on the open market for repulping.
6 to 7 times.