1. WOOD 120 Pulp and Paper

2. Raw material
Paper products

3. Chemical pulp mill

4. Chemical pulp mill

5. Composition of Paper
Surface
Section through paper sheet

6. Lignin “glues” wood cells together

7. fibers or fiber bundles
wood

8. Pulping Mechanical Uses heat and mechanical energy Higher yield
Lower quality
Chemical
Uses heat and chemical energy
Lower yield
Higher quality

9. World Pulp Production (2012) (x106 metric tonnes)
Recovered paper
Mechanical pulp
Full chemical pulp Kraft Sulphite
Dissolving pulp
Non-wood fiber pulp

10. Raw material – wood supply
Logs
Chips

11. Pulp and Paper – overview of production stages

12. Pulping

13. Pulp treatment

14. Papermaking

15. Mechanical pulping
fibers or fiber bundles
wood

16. Stone ground wood Refiner pulps
Mechanical Pulping
Stone ground wood
Refiner pulps

17. Debarking
Drum debarkers

18. Stone Ground Wood bolts of wood hydraulic pistons grinding stone
pulp slurry

19. Stone Ground Wood

20. Stone Ground Wood Raw material – short logs (bolts) High yield
Low quality fibers or fiber bundles
High energy input
Pulp suitable for tissues

21. Refiner pulping

22. Pretreatment of chips

23. Refiner pulping http://www.globalequip.com/photos/bg_901371.001_2.jpg

24. Multiple refiners in parallel

25. Refiner pulping Raw material – chips Lower yield than SGW
Medium quality fibers or fiber bundles
High energy input
Pulp suitable for newsprint

26. The “Alphabet Pulps” RMP refiner mechanical pulp
TMP thermo mechanical pulp
CTMP chemi thermo mechancial pulp
SGW stone ground wood
PGW pressurized ground wood
NSSC neutral sulfite semi chemical

27. Chemical pulping
wood
individual fibers

28. Sulfate process (Kraft) Sulfite process
Chemical Pulping
Sulfate process (Kraft)
Sulfite process

29. Kraft process Delignifies wood by
fragmenting lignin into smaller units
adding chemical groups to increase the lignin’s solubility
Tolerates wide range of species
High strength pulp
Lower yield than mechanical pulps

30. Kraft digester - continuous

31. Kraft pulping – continuous digester
Chips and pulping chemicals
Steam
Blow valve
Gases
Pulp

32. Kraft liquor recovery cycle
Wood
Pulping
Pulp
White
liquor
Washing
Bleaching
Evaporation
Cauticising
Bailing &
Shipping
Black
liquor
Green
liquor
Burning
Green liquor recovery cycle

33. Bleaching / Brightening Beating (refining)
Pulp treatment
Bleaching / Brightening
Beating (refining)

34. Pulp and Paper – overview of production stages

36. Raw material
Paper products

37. Bleaching vs. Brightening
Continuation of pulping process
Removal of residual lignin left after pulping
More permanent
Applied to chemical pulps
Brightening
Distinct from pulping process
Impact chromophoric structures in lignin
More temporary
Applied to mechanical pulps

38. Bleaching/brightening chemicals
C chlorine Cl2
D chlorine dioxide ClO2
O oxygen O2
Z ozone O3
P peroxide H2O2
E alkaline extraction NaOH

39. Bleaching/brightening sequences
Classic
e.g., C E D E D
Elemental Chlorine Free (ECF)
e.g., D E D E D
Totally Chlorine Free (TCF)
e.g., O Z E P

40. Bleaching Towers

41. Pulp Beating
Flattens fibers to produce larger surface area – increases hydrogen bonding between fibers
Unravels fibers to some degree
Optimum beating time to achieve best paper properties

42. Pulp Beating
Jordan refiner

43. Pulp Beating After beating Before beating
Internal and external defibrillation take place

44. Papermaking
Foudrinier machine - thinner paper sheet - faster production speed Cylinder machine - thicker paper sheet - slower production speed

45. Papermaking
Foudrinier machine - thinner paper sheet - faster production speed

46. Foudrinier papermaking machine

47. Foudrinier - schematic

48. Blending of pulp stocks

49. Foudrinier papermaking machine

50. Foudrinier – wet-end

51. Foudrinier – wet-end

52. Foudrinier - presses

53. Foudrinier – dry-end

54. Foudrinier – calendering and winding

55. Foudrinier – moisture loss in paper

56. Papermaking
Cylinder machine - thicker paper sheet - slower production speed

57. Cylinder papermaking machine

58. Cylinder papermaking machine

59. Schematic of cylinder machine
Couch roll
Paper layer forms on screen
Level of pulp stock
vacuum pressure
Fibres in suspension
Screen rotates
Mold remains fixed

60. Cylinder papermaking machine
Dryers

61. World Paper Production (2012) (x106 metric tonnes)
Wrapping, packaging and board
Coated paper
Newsprint