1. HEMP
AS
A RAW MATERIAL FOR PAPER MAKING
Final Year
Pulp and Paper Technology.
Seminar by,
Miss. Mayuri Kalane.

3. Hemp:
Hemp isa
Herbaceousannual
plant with asingle,
unbranched stem
which growsover
4-5 months
growing season to
aheight of about 5
m & dia.50-60mm

4. Hemp:
Hemp isknown for itslong and durablesoft
fiber.
 botanical nameCannabis sativaL.
Hemp isan annual shrub with ,yield 12-14
tonsof dry matter/hecto r.
Hemp stem isdivided into two parts:-
• Hemp Core- Relatively thin outer layer.
• Hemp Bast – inner woody part.

5. Hemp:
 Hemp CoreConstitutes
30 to 35% of fiber, with
fiber length 20 to 55mm
& width 16 to 50 µm.
Hemp Bast comprises
about 65-70% fiber,
with fiber length 0.5 to
0.6 mm & width 15 to
25 µm.

6. Need Of hemp:
Oneof themajor industriesdepending on
forestsisthepulp and paper industry
which usesthewoody /non-woody fiber
obtained from forest.
But obtaining thecontinuoussupply of
such woody fibersfrom thefragileforest
ecosystem in thefuturewill becomemore
and moredifficult.

7. The reasons for this
potential short supply of
wood are:
 pressurefrom theenvironment
 over-harvesting,
 sustainableforest management which
allowslesscutsper year though it aimsto
supply fibersfor many moreyears.
demandsfrom social corners like
recreational facilities.

8. Address to the problem of short supply of
wood and increasing demands:
 Improvethe technology to makethebest
useof availablefibers.
 useother fiber resourcesLikenon-woods.
promotemorerecycling of paper.
makebest useof theavailableresiduesof
round wood from other industriesfor pulp-
making.

9.  Asaresult industriesarelooking either for
inventing changesin thetechnology to
improvetheefficiency of theuseof
harvested wood or research for some
alternativeraw materials.
 In fact, from16" century to 18" century,
much of thepulp produced wasfrom non-
woody fiber, especially from hemp.
But dueto thedeveloping new technologies
and cheaper woody fibers resulted in the
declineof hemp .

10. Narcotic Issue of Hemp
Therearemany different varietiesof
cannabisplants. Marijuanaand hemp come
from thesamespeciesof plant, Cannabis
sativa L.
 but fro m different varieties o r cultivars.
Ho wever, hemp is genetically different and
isdistinguished by itsuseand chemical
makeup.
Hemp containsonly 0.3-1.0% of THC

11. (delta-9 tetrahydrocannabinol, psychoactive
chemical).

THC.

12. Marijuana refers to the flowering tops and
leaves of psychoactive cannabis varieties,
which are grown for their high content of
THC about 10%; some sample tests indicate
THC levels reaching 20%-30%, or greater.
As well growing Hemp for THC is
uneconomical
Marijuana and Hemp are easily
differentiable.

13. Reasons for using Hemp :
 Hemp can help to providesustainable
fiber resourcefor pulp production5-8 tones
of fiber per acres.
Also hemp cultivation needsmoderateuse
of fertilizers.
o Nitrogen :12 kg/ton of dry matter.
o Potassium: 15 kg/ton of dry matter.
o Phosphorous: 4 kg/ton of dry mater.

14. Usehemp can decreasethepressureon
forestsand theenvironment.
 lessenergy isrequired for using hemp in
pulp production.
Lignin content in hemp islessthan that of
wood, which meanslessuseof chlorinefor
pulping, bleaching and potential increased
useof alternativemethodsof non-chlorine
bleaching.
Finequality paper from hemp can be
recycled 7to 8 times.

15. Soil condition:
SiteRequirement:
Hemp issaid to grow best on fertile, well
drained, medium-heavy soilsand especially
well on silty loams, clay loams, and silty
clays. It can grow on again widevariety of
soil types. A pH of lessthan 5 hasbeen
reported unfavorableto Hemp Production.

16. Climatic Condition:
Climatic Condition:
Climatic Condition of thenorthern plains
arefavorableto hemp production.
Agro climatic conditionsof Assam and
other Northeast region in Indiaarevery
much suitableto grow Hemp in India.

17. Cultivation of Hemp
Seed bed: It should besimilar to cereal bed
and freefrom weeds.
A stableseedbed made
in march and cleaned
beforedrilling during
lateApril/early May is
needed. Organic
fertilizer need to be
worked into theseed bed.

18. Hemp grown in green house.

19. Cultivation includes:
Drilling: Theseedsof Hemp aresowed at
an averageof 30kg/acre. Theseed must be
drilled with aconventional 4inch cereal
drill into moistureto thedepth of 2 inch.
Rowsof Hemp plants
wereabout 7 inches
apart with 2 inches
distancebetween the
plant in each row.

20. Harvesting procedure for Hemp
Hemp harvesting
would bedone
early September.
Processincludes:
Cutting
Turning
Bailing
Retting

21. Harvesting Procedure
Cutting: Thecrop is
cut with o mower
or swather .
Turning: Turning is
donewith arotary
rake.
Baling: Turning in
Baleswith Baler.

22. Retting of Hemp
Retting isdoneto separatebast and Core
fibers.
It iscarried out by immersing theHemp
stalksin water in streams, pond, or artificial
tanksfor 8 daysand second timelittlemore
days.
Thisprocessin completewhen thebark,
including thefiber, getsseparated from
stalks.

23. Hemp production in tonnes 2003–2004
FAOSTAT (FAO)
China 23000 79 % 24000 79 %
France 4300 15 % 4300 14 %
Chile 1250 4 % 1250 4 %
Russia 200 1 % 300 1 %
Turkey 150 1 % 150 < 1 %
Ukraine 150 1 % 150 < 1 %
Romania 100 < 1 % 100 < 1 %
Hungary 40 < 1 % 40 < 1 %
Poland 15 < 1 % 15 < 1 %
Spain 8 < 1 % 8 < 1 %
Serbia and Montenegro
2 < 1 % 2 < 1 %
Total 29215 100 % 30315 100 %

24. Morphological PropertiesOf Hemp
Fiber.
Properties Hemp Core Hemp Core
Fiber Length(L)(mm) 0.5-0.6 5-55
Fiber Width (D) (µm) 15-25 16-50
Cell Wall Thickness ,
(µm)
3 14
Slenderness ratio
(L/D)
27.5 1000

25. Chemical Analysis of Hemp:
Raw
Material
Hemp Core Hemp Bast
Cellulose % 36.3 71.7
Lignin % 27.1 4.0
Extractives% 1.2 0.9
Ash % 1.2 1.5

26. Pulping of Hemp.
Following TypesOf Pulping Can becarried
out with Hemp asaRaw material:-
Kraft Pulping
SodaPulping
Organosolvepulping
Alkalinethermomechenical Pulping
Chemithermomechenical Pulping

27. Pulping
Kraft Pulping of certain fiberswascarried
on at samepulping conditionsand
compared :
Cut Hemp stalk or Corefiber.
Hemp bast fiber.
Hemp wood retted.
Hemp wood non retted.
Birch.
Pine.

28. Cut Hemp
Stalk
Uncut & Cut
Hemp Bast Fibers

29. Hemp Wo o d
Retted
Hemp Wo o d
No n Retted

30. Pulping process:
 Kraft Pulping
conditions:
 Bath Ratio 1:6 for
Bast fibers & 1:5 for
Stalk fibers.
 Temp. was raised to
165 °C in 90 min. &
retained for 90 min.
 Sulfidity was varied
from 4-26%

31. Fig.1RelationshipbetweentheKappanumberandtheamount
of activealkaliaddedintheprocess of thedelignificationof hempraw
materials andbirchandpinewood.

32. Fig.2Comparisonof pulpyields fromindustrialhempraw
materials andconventionalones fromwoodattheir
differentpulpinglevels.

33. Oxygen Delignification of Hemp
Oxygen Delignification of Hemp Bast Fiber
as carried out at following conditions:
Oven dry fibers: 40gm
Consistency: 8%
Oxygen pressure: 6 Mpa at 100 °C
0.1% MgSO4 dissolved in water.
NaOH charged up to 2%
Time 60 min.

34. Fig.3 Variations in the Kappa number of hemp bast fibers
in the oxygen delignification process depending on the
amount of NaOH used.

35. Fig.4 Yield of hemp bast fibers in the process of their
oxygen delignification compared with that in the process of
delignification with Kraft cooking liquor

36. Bleaching of Hemp
Bleaching of Hemp wascarried out using
four stage(DEpAp) Procedurewith
Chlorinedioxide(D),Extraction (Ep), Acid
(A), Peroxide(P) stagesin sequence.
Procedure:
In thefirst step, thepulp of 3.5%
consistency wasacidified with dilute
sulfuric acid. Sodium Chloritesolution was
added in proportion to thekappanumber of
pulp.

37. Thetreated pulp wasthen kept in thewater
bath at atemperatureof 50 °C for 60 min.
Pulp wasthen washed carefully and used
for theextraction stage.
In theextraction stage, consistency of 10 %
wasapplied and NaOH (2 % of theO.D.
basis) and peroxide(1 % of theO.D. basis)
wereused for extraction. Thisstagewas
retained for 90 minutesat atemperatureof
80° C of water bath. After completion of
desired time, pulp waswashed with cold
distilled water & used for thenext step.

38. In theacid stage, at 3% consistency Pulp
wasacidified with the1 % acid (O.D. basis)
and retained for half an hour at a
temperatureof 50 °C. At theend of 30
minutes, pulp waswashed with distilled
water, and thelast stageof peroxidewas
then carried out.
At 10% Pulp consistency the chemicals
magnesium sulfate(0.25 %). DTPA(0.25
%), NaOH (2%) and peroxide(3 %) were
added in Pulp and wasthen mixed well and
retained in water bath at temp. of 80 °C
for 4 hours.

39. At theend , pulp waswashed with the
distilled water to removethechemicals
used and then collected and weighed.
Moisturecontent wasmeasured to
determinetheyield of thebleached pulp.

40. Physical properties of pulp
Particulars Hemp Core pulp
Yield of unbleached pulp% 58
Yield of bleached pulp % 54.4
Brightness Of Bleached pulp
%
80.2
CED Viscosity at 27°C (cp) 28.4
Initial Pulp Freeness (°SR) 16

41. Hand Sheet Making
Hand sheetsof 60 gsm weremadefrom
both thebleached and unbleached pulp
using British hand sheet former.
Hand sheetsweredried at temperatureof
around 23 °C with relativehumidity of
50 %.
Hand sheetsweretested and strength
propertiesweredetermined.

42. Physical strength properties of Paper
sheet.
Strength
properties
Unbleached Bleached
Bulk density (cc/g) 1.50 1.38
Burst Index
(kPa sq.m /g)
5.80 4.32
Tear Index
(mN Sq.m /g)
11.77 8.37
Tensile Index
(N m/g)
62.67 48.17
Folding endurance 320 125
°

43. Blending of hemp
 To evaluate the properties of paper from
the blending of pulp, the Bast fiber pulp and
the core fiber pulp were blended at a ratio
of 50:50.
Hand sheets were prepared and tested and
the physical strength properties are
presented in Table

44. Physical strength properties of Bleached
Paper sheet made by Blending.
Strength properties Bleached Blended sheet
Bulk density (cc/g) 1.42
Burst Index
(kPa sq.m /g)
5.80
Tear Index
(mN Sq.m /g)
9.85
Tensile Index
(N m/g)
56.60
Folding endurance 190

45. Investment for hemp assuming high yield, small
module scale & no recovery system. Investment is
calculated for 5000ton/year Pilot Plant.
Operation Annual Cost/Tone US$
Investment Estimate
Refit 480
Greenfield 600
Operational Cost
Fiber Crop 130
Pulping Operation 400
Total Cost 530
NBSK* 950
Non Bleached Softwood Kraft pulp is used as a reference

46. Cannabis sativa. Height 2.5m

47. Problems encountered in use of
Hemp fibers
 Theirseasonality
 Large storage area is needed,
Degradation of the fibers due to
impropercare in storage.
 Requires high input and costlier

48. Conclusion
Hemp can positively
seen asaraw
material for paper
making.

50. Cost (US$/tone)
process Hemp Hemp Softwood
Chemical Chemomec
henical
Chemical
Pulping 2,100 530 820
Paper
making
1,900 800 800
Total Cost 4,000 1,330 1,620
Cost of Chemical and Chemomechenical pulping
processof Hemp VsChemical processing of
Softwood

51. Proximate Chemical Analysis Of Hemp
Particulars C. Sativa
Solubility %
1. Cold water 4.2
2. Hot water 12.84
3. 1% NAOH 27.6
4. Alcohol Benzene 3.61
Cellulose % 50.8
Lignin % 4.8
Ash % 4.5
Silica % 0.75

52. Uses of hemp
• Hemp fibersareused in awiderangeof products,
including fabricsand textiles, yarnsand raw or
processed spun fibers, paper, carpeting, home
furnishings, construction and insulation
materials, auto parts, and composites. The
interior stalk isused in variousapplicationssuch
asanimal bedding, raw material inputs, low-
quality papers, and composites. Hemp seed and
oilcakeareused in arangeof foodsand
beverages, andcan bean alternativefood protein
source

53. • Hemp seed is also used for
industrial oils, cosmetics and personal care,
and pharmaceuticals, among other
composites