Product Design
Cigarette Design
Abstract
Detailed discussion of cigarette paper, filter, and tip ventilation, and their influence on smoke delivery. Notes the addition of chalk and salt additives to cigarette paper to control ash formation and modify burn rates; and the modification of paper permeability (measured in CORESTA units), either through paper porosity or the addition of electrostatic or mechanical holes, to reduce tobacco burnt during each puff and alter burn rate and puff count. Describes how filter may be used to alter the character of smoke by removing smoke constituents either in the particulate or vapor phase of smoke. Discusses measurement of the effectiveness of the filter, or filtration efficiency (FE). Describes tip ventilation, the process of introducing holes in the cigarete wrapper to allow air dilution of mainstream smoke thereby reducing delivery. Also describes in detail the formation of "Cigarette Smoke", including combustion process, generation of smoke, methods of measuring and reporting components of smoke, delivery of nicotine and other components, and tobacco grades and blending practices influencing or controlling component variability. Identifies filter pressure drop as the most important product factor influencing delivery variability of non-ventilated products. Ventilation is shown to be critical in development of low-delivery cigarette.
Fields
- Rank
- 1
- Hypothesis
- FTC machine testing and ratingsDesign changes to achieve altered FTC smoke machine tar and nicotine ratings, with or without measured changes in human intake.
- Low-yield cigarettesModification of low yield products to assure that adequate levels of nicotine delivery are maintained, and effects of yield changes on toxicity and dependence.
- Mainstream constituent yieldsModification of selected mainstream smoke constituents in response to health concerns.
- Nicotine transport, transfer, and uptakeDesign changes which alter nicotine delivery or effect how the product causes and maintains dependence, including transfer of nicotine from tobacco to smoke, and uptake into the body.
- Use of additivesModification of tobacco products through use of additives and measuring effects on dependence, behavior, and toxicity.
- Use of filters, paper, and ventilationModification of tobacco products through use of filters, paper, and ventilation, and measuring effects on dependence, behavior, and toxicity.
- Use of tobacco processing/ blendsModification of tobacco products through changes in tobacco processing and use of blends, and measuring effects on dependence, behavior, and toxicity.
- Elasticity and Product Control
- Design Basics
- Keyword
- Free nicotine (Unprotonated or unionized nicotine)
- Impact (Throat grab)
- Smoke pHAcidity/ baseness, scale from 0-14, 7 neutral
- Pyrolysis
- Respiratory system
- Acidity (Low pH)
- Alkalinity (High pH, Basic)
- Bullseye effect
- Exhaled smoke
- Additive
- Chalk
- Disodium hydrogen phosphate
- Potassium citrate
- Salts
- Sodium citrate
- Smoke Constituent
- Carbon monoxide
- Total particulate matter
- Gas phase constituents
- Particulate phase delivery
- Total particulate matter
- Dry TPM
- Dry TPM
- Total particulate matter
- Total nicotine alkaloids (TNAs)
- Design Component
- Cellulose acetate filter (CA filter, Conventional filter)
- Air dilution
- Electrostatic perforation 1 (EP)Method for manufacturing @filter_ventilation to alter @air_dilution
- Flax paper (Flax wrapper)
- Hemp
- Natural paper permeability 2
- Paper filter
- Plug wrap (Plugwrap)
- Tipping paper
- Tobacco grade
- Viscose filters
- Woodpulp fiber
- Pressure drop (PD, Resistance to draw (RTD), Flow rate or Draft)
- Coal
- Combustion
- Combustion zone
- Filter efficiency 3 (FE)
- Ash formation
- Static burn rate 4
- Temperature
- Filter ventilation (Filter vents, air vents)
- Named Organization
- Hauni
- Technology/Method
- Cambridge filter pad
- Electrostatic spark perforator
- Hauni tipping attachments
- CORESTA
- Subject
- aerosol (technology)
- Burn Rate (Design)
- Smoke Delivery/Transport (Measures)
- Filters (Design)
- Paper (Design)
- Particle Size (Technology)
- pH Manipulation (Technology)
- Puff Count (Measures)
- Smoke Constituents
- Smoke Nicotine (Measures)
- Smoke pH (Measures)
- Sugars (Additives)Glucose/Invert Sugar/Fructose/Sucrose
- T/N Ratios (Measures)
- Tobacco Weight (Design)
- acids (additives)
Annotations
- 1. Electrostatic perforation Design Component
- Synonyms:
EP
- Synonyms:
- 2. Natural paper permeability Design Component
- Synonyms:
NP
- Synonyms:
- 3. Filter efficiency Design Component
- Synonyms:
FE
- Synonyms:
- 4. Static burn rate Design Component
- Synonyms:
SBR
- Synonyms:
Document Images
BAT Co L~ - M*-','.~'~so~.a To~,~cco Lrr~¢ario.~. ~
CIGARETTE DESIGN - A~( OVERVieW
I~TRODUCTIOt;
A cigarette can con'~enien~ly be Cescribed aS a four component
i.
2.
3.
4.
Cigarette paper
Filter
Tip ventilation
Blend.
In order to ~eet the defined market brief, these are the four components
which can be modified. In this paper we will consider what charges can
be made in the first three components and the effects these changes have
on the deliveries. It is extremely important to appreciate how these
four components may be brought together to end up with a product or
products which are likely to satisfy both the subjective and the objective
requirements given in the brief.
I. CIGARETTE PAPER
Cigarette paper is not just simply the white wrapping material
used to hold the tobacco in the cigarette. By virtue of its physical
end chemical characteristics, it has a fundamental influence upon the
quality, the appearance and the ~o~bustlon of the cigarette~.
Most papers ire based on ~ax, hemp and woodpulp fibres and
contain 20-30% chalk, The chalk serves to increase the opacity of
the papers end to cause formation of an attractive white paper ash.
Along with the chalk, salts are added to the paper for three main reasons,
viz:
e) To minimise the tendency of cigarette paper to disco|our during
storage:
/2
b) TO control ash formation.
c} TO modify the burn rate of the cigarette which in turn can infZuence
the deliveries tca limited extent. This wit] be c:nsidered in
more detail later in the paper.
The pr:perty of the c~ret~e paper that has the ~ost
significant effect on deliveries is its PERMEA.~ILITY which is usually
specified in CO~E~TA Units. The CZRESTA Unit is defined as the flo'~ of
air in cm3/min through a sample O~ ~aper Icm2 in area when a pressure
difference of 10c~ water is applie: across the paper. The more porous
the pa~er is, the higher will be the air permeability as measured in
CORESTA Units.
The desired level of air permeability for the paper may be
achieved in two ways:
I. By making the paper inherent~ porous during its manufacture, This
is normally referred to as the Natural Permeability {NP) end the
normal commercially available papers cover a permeabilltx range
from B to 200 CORESTA Units.
By passing an inherently porous paper through a secondary process
where devices puncture, burn or cut holes in the paper. ~hese
holes tend to be considerably larger than the pores of the NP papers.
The most tone.on method of introducing holes is to use an
Electrostatic Spark Perforator and hence these papers are referred
to as [P papers.
One general effect of increasing the ~ermeabi~ity of ~be paper
(NP and/or EP) is to reduce the weight Of tobacco burnt during the puff.
7he reason for this being that as a fixed volume of air is drawn through
the cigarette, higher permeability paper will let in more air through
the paper envelope (dilution) and thus a lower volume of air wtl~ pass
tb-ougn the burninq coal. The effects of increasin~ permeability
• a/ be sum~arised as follows:
I. St~:ic burn rate (SBR) increases as we increase NP from very low
tz about 70 C.U. and thereafter the chanqes are small. ~ possihl~
reason being that as NP is increased, more oxygen becnmes avai:ab~e
fz, efficient combustion but at around 70 C.U. enouoh oxygen
available and hence there is very limited effect thereafter.
2. i-:roducing EP to a base paper does not alter the static burn
Increasing NP UD to about 70 C.U. results in reduced puff number
because although a lower weight of tobacco is consumed during the
puffs, the weight of tobacco consumed between puffs increases more
rapidly as illustrated in the Slide. Beyond this level, there is no
change in SBR but the weight of tobacco consumed during the puff
reduces and hence a sllg~t increase in puff number is observed.
BAT Co LTD - Mixx so r. Tobacco Lrno, 'rio.,,-
[ntroducinq 6P does not a)ter the 58R but reduces the wefghc of
tobacco consumed pe. buff and hence ~ncre~ses thp buff number.
Increasing NP reduces deliveries with a greater reduction being
observed for CO, followed by tar and nicotine. Thus, tar to nicotine
ratio will reduce.
EFPECT OF CHANGING THE NATURAL
PERMEABILITY OF CIGARETTE PAPER
ON SMOKE ~ELIVERtES
BAT Co LTD - M~.~o~..~, To,~,~cco Lmo,~'ndx-
Similar effects occur from increasing E~ but the effects a~e lowe~
tbam for NP beCause whereas NP affects both SmR amd level of
dilution EP only affects the level of dilution.
EFFECT OF ELECTROSTATIC
FE~,FORATION OF CIGARETTE PAPER
ON SMOKE DELIVERIES
PERMEABILITY (CORESTA UNITS)
Turning now to the additives, the followlng chemicals in the
range 0.5-3% are in common use:
~onoan~onium Phosphate is added as an ash conditioner and only slightly
increases the burn rate of the cigarette compared to oaper with no
additives which are the slowest burning papers.
~isodium H~dro~en Phosohate increases the burn rate of the clqarette
relative to that found from using the monoar~aunium phosohate additive.
Sodium and Potassium Citrates are most commonly used as burn accelerators.
This reduces tar delivery per cigarette by reducing the puff number as a
result of more tobacco being consumed in between puffs. However, tar
delivery per puff should not be slgnlficantly affected.
BAT Co - M xx soT., Tobacco Lmo, Tiox
/6
phosphate ~disodium hydrnq~n Ohosnrate ~¢itr!~ - fast~st hur~inl.
2. FILTE:
to divide filters intn twn grm, os - thnse which mainly remove smnk=
vapour phase. A rigid sun-division is not possible since m~ny smnk~
constituents (semi-volati]es) are ~r~sent in both ohases and it is
possible to design filters which are effective for both phases of smnke.
In this p~per we will concentrate on filters for the ~articulate
~ost cigarette filters which remove particulate phase consist
of fibrous or filamentary materials which capture the smoke particles
they pass through. Over gO~ of the filters used conlnercially are
cellulose acetate, with the remainder being paper and viscose. Further,
much of the paper used goes into dual filters with the paper section next
to the tobacco and the acetate section st the mouth end.
The effectiveness of a filter is measured by its filtration
efficiency (FE).
FILTRATION EFFICIENCY (,FE)
/ 7
* ~o0
Various filtration s:udies have shown that, in general,
fi]:ra~ion efficienciss are i~imately related to the pressure drops in
filtration e~ficiencies. Thus, for extols, increasing the length will
increase both preSSure drop an¢ FE. However, the absolute increase in
oressure drop and FE will n~t be identical. This is illustrated below:
EFFECT OF LENGTH ON PRESSURE DROP AND FE
BAT Co LrD - Mz.xx~soT.~, To~.o l ~,~.~4,~,-
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FILTRATION EFFICIENCY - T~M & NICOTIHE
25ram CA FILTE~
Some brands also use a dual filte- which consists of a length
of paper filter next to the tobacco (referred to as the 'T' section),
followed by a length of cellulose acetate filter at the mouth end (or the
'M' section). This filter cosines the advantages of high]y effective
paper filters with the acceptable white end appearance of cellulose
acetate filters. The filtration efficiency of each section can be
adjusted to particular requir~ents and following the logic i11ustrated in
Slide 6 it can be shown that the combined efficiency is:
FEdual • FE paper + (100 - FEpaper) FECA
100
where FE is the percentage filtration efficiency for the particular
section used in the dual filter.
3. TiP VEHTILATIDN
Ventilation, in simple terms, is the process of Introducl~g
holes in the wrapper of a cigarette. The holes allow air to enter the
mainstream smoke when the cigarette is smoked. The air thus entering
BAT Co - MixxEso'r. To . .co
110
the cigarette is not used to burn the tobacco, Hence, less tobacco w111
be burnt during each puff and the delivery of smoke reduced.
Tip ventilation, ~ore specifically, is the amount of air
entering through the tipping/plugwrap combination and is normaR]¢
expressed as a percentage O~ the total volume drawn through the cigarette.
The relationship between bercentage tip ventilation and delivery
reduc:ion for the nx)st common s~oke constituents measured is:
OVERALL~
60
40
20
VENTII-~TION ('~) -- UNLIT CIGAR=TTES
The line for PHWNF is an approximate 1:1 relationshio, i.e.
percentage tip ventilation approxfmately equals percentage reduction of
PMWNF. For nicotine the reduction is less at any oartlculer level of
ventilation relative to tar end therefore as tip ventilation Is increased
the tar to nicotine ratlo reduces. The reduction for CO |s greater than
BAT Co L'r
