RESEARCH & DEVELOPMENT ESTABLISHMENT.
BrItIsh-American Tobacco Co., Lt.d., Southmpton.
D.S.F.HOBSON. ESQ. C.opy NO ... 3.....
Research & DeveloFwent EBtablishnent
British-luerican Tobacco GoAtd.
Southampton.
REPORT 10.1D.7A
UUjs TOBACCO AS A FILTER MEDIUM (FAfM II)
Authorat I.W.Rughes.
D.Forter.
joisued b!ri R.D.Anderson. Date of Tesimi 16th
January. 1959.
D44r4bution: Copy 11o.1 Ywter
No.2 File 46B
No-3 D.S.F.Hobson, Esq.
N0.4 Sir Charlos Ellis
No.5 L.C.Laporte, Esq.
No*6 T.H.Wade, Jnr.,Esl.
No.7 L.Hinshelvood, Ea-1.
No.8 Dr.H.H.Evers.
No.9
No.10
No 12
No:12
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BATCo document for Province of British Columbia 29
October 1999


RESEARCH & DEVELOPMENT ESTABLISHMENT.
British-American Tobacco Co.. Ltd.. Southampton.
Research & Development Eatablishrr?nt
British-Averican Tobacco COAM.
Southampton.
8 th Jenua17, 1959.
LO-BACCO AS A FILM PfCnIUM (PART II)
A"MT 30. 1W.71
Report No. RD.32 described the preliminary work
carriecl out
to dateraine the variation in the filterim~r power
of a tobacco
blend with the cut of the tobacco.
A mmary of the results Is given in T able 1.
TABLE I
Coefficients calculated from data givm in VD.32.
Filter rods made at 22 rods/on. and 25 rm.
circurferarice
fro- 04.86 %,-a
Cuto/
In Filtration
ff
.(iTJ.Lcyj1 Coeff. of
Impedance
sec./cme Coeff. of
Filtratizi (k-)
cm. Cuerf. of
Retention
90 C.-1
so 10 0.052 0.081 1.6
150 16.5 0.o66 0.139 2*1
200 23. 0.074, 001183 2.5
B#Ap at 20 roovs/oe.
80 .5 21.5 0.085 0.185 2.2
150 27.3 0.088 o.246 2.8
200 30-3 0.091 0.282 3.1
The sain conclusions reached weres-
(i) Increased drav resiatence with increasad
filtraticn
occurred an the tobacco vas cut wre finelv.
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BATCo document for Province of British Columbia 29
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RESEARCH A DEVELOPMENT ESTABLISHMEJ,
British-American Tobacco Co., Ltd.. Southampton.
(ii) of those examined, the most efricient filtcr
roi vnrs
Oat xa" frow t0woo cut at 2D0 cuts/inch. This
filter compared
favourably with cellulose acetate filter (5/1W,000
specification)
of the same length.
(:Ui) Tobacco filters, thou& having a filtration
efficiency
approximately equivalent to that of cellulose
acetate, gave the
smoko considw-abljv greater tobacco character.
As a contizu, 4on of this vork, it was decided to
exurDne
Us filtering power at eve finer auts/inch than
20.), and vlao to
compare the effectivweas of C.R.S. filters to
those made from
1-11an alone. Aaccirdingly, filter rods were
manufacturel at
Liverpool both from latina, and from C.R.S. at ZJ
and 22 rods/oz.
A. PALUATION OF CQ.86 T-UnNA ADD X0.1 G.R.S.
FILTEW HADE AT 20 R(MV0.1
The filter rods were made with the following
specifications.
TABLE 2
CQ.96 'L-4,,- Filter rods (78 - 25m.) made at 20
rods/oz.
so. cuts
inch
200
220
300
Av. vt.
filter rod
(ff.)
1.,32
1.36
LAI
Are Pressure Drop
(=*WoG )
^t 1.250 -l:/1-+n.
2792
29 o7
4 o.6
Calculatei
coef.r. of Impsdance
(sec./cm.)
0,085
0.092
0.125
No. I C.R.S. Filter Rods (78 x 25m.) at 20
rods/oz.
200 1.28 25*3 0*081
220 :L.31 28.7 0.088
500 1.38 36.o 0.njL
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BATCo document for Province of British Columbia 29
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RESEARCH & DEVELOPMENT ESTABLISHMENT.
British-American Tobacco Co., Ltd., Southampton.
-3 -
froced"ve for determin4rie, F4'trwt4evn Wficiency
The six types of filter rods were conditioned for
several
days In the humidity cabinet which is In
equilibrium with Ploverts
"'Medium" cigarettes at 121%. After conditioning,
thi rods were
sawted an a weight =d drav resistance basix (i.e.
av. weight
:L 2%1 averw proaxwe drop 1,4%). From the selected
rods,
lengths of U, 13 and 15 m. were cut, weighed and
attached to
60 am. lengths of weight and draw selected
Plover's "Hodium"
cigarettes.
Bwklw:- Smoking was carried out on the I.T.Co.
autoenoker
vhich gavv 4 puffs a minute, each puff of volune
15 ml. and 2
seconds duration. In allowes, 52 mm. of cigarette
rod was L-=it,
lenUg a butt comprising 8 mm. of cigarette rod
plus thi length
of filter.
01 m completion of woking, the filters were
carefully detacbel
from the tobacco butts, and the nicotine and
solvent-extractable
cmtonts determined (W 2 ).
Mai determInations were made on equivalent veiahed
unsmoked
filters (WI).
Thus
Tar or nicotine retained by the tobacco filter is
W 2 1
Tar or nicotine in the collected smoke is W
3
Filtration Efficiency = W 2 W1
(W -W + W x 1001%,
The fIltration efficiencies of the various
tob=t.-o filtcrs are
presented In Table 3.
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BATCo document for Province of British Columbia 29
October 1999


RESEARCH & DEVELOPMENT ESTABLISHMENT,
British-American Tobacco Co.. Ltd.. Southampton.
-4-
TABLIC I
Filter rodo (78 X 25me.) Made at 20 rods/oz.
(CQ.86)
Lamina Filters G.R.S. Filters
CUte/Ineh 200 22) 500 29U 220 5UU
Filtration %
Efficienc-7
at n rn. 30 33 39 A 33 A-6
at 13 rim. 32 37 45 37 331 59
at 15 mm. 37 41 49 4') 42 5 1#1
(These results are treated graphicany, in ri,,.l
en(I 2)
In Table 2, Coefficients of
calculated using the approximate relationship
V 11
From these approximate fiVxas r-nd the -.~-ove
filti-rfii-i
efficiencies, values for the Fetention
Oo-~.rficicnt!3 hare bi~n
calculated and are listed in Table 4-
TA13LE 4
(CQ.86)
T-PM41na Filters G.R.S. Filters
Cuts/inch 200 220 50U 2,,)9 220 30;3
Coeff. of
Filtration 0.31 0.35 0.44 0,35 0.365 0
53
cm,-J. .
Coeff. of.
Impedance W 0.085 0.092 0.125 0.081 0.0318 O.ill
Coaff. of
Rete:1 ion W) 3.6 3.7 3.5 4.3 /~.15 At."
see.
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BATCo document for Province of British Columbia 29
October 1999


RESEARCH & DEVELOPMENT ESTABLISHMENT.
British-American Tobacco Co., Ltd., SoWhamptan.
- 3 -
B. RVAT.UATION OF LA14INA AND C.R.S. FUTERS MADE
AT 22 RODS/OZ.
TABLE 5
(9 Q.86) T_-n4inm Filter rods (78 X 25"%.) made at
22 rods/oz.
110.0uts AT. Wt. Av. Fressure Drop Coeff. of
Impedance (f:)
/inch fllter rod (cm.W.G.) (sec./cm.)
(it. ) at 1.250 ml./min.
200 1.26 22.. 0.068
220 - - -
500 1927 30.5 0*09/4
No-I) C.R.S. Filter rods (76 x 25w . 4 22 rods/o
s.
200 1o25 24.7 0.076
220 1,26 28,,2 0,087
500 1*28 31.8 0.097
TABLE 6
filter rods (78 x 25mm.) made at 22 rods/qz.
(CQ,86) (110.1)
11-o-lina Filters C.R.S. Filters
cuts/inch 200 220 500 200 220 5J)
Filtration
Efficiency
at U X2. 25 - 35 24 28 33
at 13 MR. - - - Z7 31 49
at 15 am. 31 - - 35 48
(These results are treated graphically in Fig.1
and 2)
The calmdated Retention Coefficients are now given
in
Table 7.
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BATCo document for Province of British Columbia 29
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RESEARCH & DEVELOPMENT ESTABLISHMENT
British-Arnerican Tobacco Co.. Ltd.. Southampton.
TABLE 7
filter rods (78 - 25 -.) made *t 22 rods/oz.
(CQ.86) (-No. 1)
kri"A Filters C.R.S. Filters
Cuts/inch 200 220 500- 200 220 500
Coeff. of
Filtration (K) 0.25 - 008 0.25 0.3 0.43
cm.-l
Coeff. of
Impedance (J-) 0.068 - 0.094 0.076 0.087 U.097
see./cm.
Coeff. of
Retention
Z (6-) 3.7 - 4.0 3.3 3.5 4.5
i
sec.
Conclusions
1, An already shown in Report flo. PD.32, filtcrs
rn,le fron
tobacco cut increasingly finely have higher drw.!
rcsiatrnr-o vith
concomitant increase in filtering power.
2. Lamina has an average retention value of 3.7
a--id C.R.S.
of 4.1 - theme figures are somewhat high, since
they Kavo b-:!en
calculated using an approximate Impedance figure.
Dowever, these
results suggest that C.R.S. if anything is a
sligbt!7 bettor filter
material than Lamina. This might be expected since
atcr. has a
more open structure than leaf and the rolling and
cnttinf,, itoad
tend to provide a more absorbing surface.
3. The retention values for Lamina and C.P.S. are
higfv~r than
those or the tobacco filters reported in U-32. Tbi
a:!rnl"
provided for that report were already-assonbled
filtcr-tip c1!-,nrottci
CZ)
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BATCo document for Province of BritiSh Columbia 29
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RESEARCH & DEVELOPMENT ESTABLISHMENT.
British-American Tobacco Co., Ltd.. Southampton.
-7
(13 mm. lengths of the various tobacco filter
plugs atttch,?d to
Player's "Medium" cigarettes by eark tipping), and
these presentel
practical difficulties, such as cutting And
matching filters for
blank determinations and measurements of pressure
drop, etc.,
which did not arias in the vork reported abave.
4. This is the final report on tobacco as a
filtering midimm,
and shmm that the natural naterial (tobacco)
compares very favourably
with ouch filters as 51100,000 Estron which
possess a Coefficient
of Retention of 2.3 under smoking conditions of /+
pugh p,= minute
of 15 MI. volume. Unfortunately, 'Prior Art'
prevents the patenting
of tobacco in various forms as a filter material,
and inJoed the
use of stem material as a filter is covered in
patent0lo.781,960.
1 WH
G~RM/A+61L
BATCo document for Province of BritiSh Columbia 29
October 1999


p 4 6 8 io t2 t4 16 IS to
-0.1
-0.3
-0-4 (D
-0.6
J
-0-6
-0-7
-0.9
-0.9
L E N wr w c F P i L-r E;z
2 O0*C.tSjLACk
20-0 cuts/kKek
Z?Q cuts/LKck
1,500 CutS/LKCk
SOO CU.tS/LKCk
LAMINA FILTERS
Loqj,(1-4P)aq0LtKSt L*Kgtk 0; 4LLtar.
(Wke re e = FtttV-M'tLOK e*ftCLCKC-,4)
0-0 LAMINA FiLTEFLs at 20rocis/0-3,
LAMINA FIL-rFuts ckt 22 vcoLs/0:5.
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BATCo document for Province of British Columbia 29
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4 6 8 10 12 14 1 G Is SO
LENGTH OF FILTER
-0-2
200cut-VtKck
`1220 cuts/tKck
-0-3 2:0c) C,,tS/k,-tCk
-o-4 1500 CLAI./LH Ck
4 D
1 500 Cuts/LRCk
-0-5 Ft.g(fi) ICA.S FILTERS
GrcLpk o4- toglo(I-G) agCALKSt I:LtteV 14ZPtgtk
(WkCV'ee= FLLtr0AL6KC;fLcteKc4
-0-6 0 0 CA.S. FiLTsp-S oLt 20vads/o3.
6---A C.;Z.6. FILTERS ott 22 ~-octS/0-5
-0.7
-0.8
-0-9
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BATCo document for Province of British Columbia 29
October 1999


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BATCo document for Province of British Columbia 29
October 1999