Product Design
"A Review of Filters Which Generate Smoke Swirl, and Their Sensory Properties."
Abstract
Summary of "the history of swirl" and its sensory benefits. Describes shift in BAT filter research from control of smoke components to enhancement of sensory properties of smoke. Explains use of filters to swirl smoke as it emerges from filter and into smoker's mouth, enhancing smoke taste. Describes development of early grooved filter prototype, the Actron filter, which became one of the features of the Barclay cigarette. Notes Actron filter keeps smoke stream and ventilating stream apart until they exit from the cigarette, creating a more turbulent flow pattern. Links use of the Actron filter to "spatial summation", "when the highest number of neurons can be caused to fire at the highest rate, i.e. the given dose of smoke in this case has been caused to reach as many active receptor sites as possible as fast as possible, thus causing the maximum stimulus to the smoker." Describes delivery controversy resulting from introduction of Barclay (due to differences in machine and human smoking conditions) and introduction of Actron Plus and a number of prototypes developed under Project Kilt in response. Prototypes include tube filters, slot filters, and center-jet filters. Summarizes BAT "swirl conference" presentations concluding that swirl offers "demonstrable sensory benefits."
User-Contributed Notes
Fields
- Rank
- 1
- Author
- BAT UK & Export Ltd.
- Greig-C
- Hypothesis
- CompensationIncorporating knowledge of compensation and effects of human smoking behavior into cigarette design.
- FTC machine testing and ratingsDesign changes to achieve altered FTC smoke machine tar and nicotine ratings, with or without measured changes in human intake.
- Introduction of new/unconventional productsResearch and development of novel nicotine delivery devices and experimental tobacco designs.
- 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.
- Measuring human intakeDevelopment of scientifically valid procedures for measuring tar and nicotine levels that more accurately reflect human intake.
- 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 filters, paper, and ventilationModification of tobacco products through use of filters, paper, and ventilation, and measuring effects on dependence, behavior, and toxicity.
- Elasticity and Product Control
- Smoke Control
- Sensory effectsTechnologies used to measure, control, or alter sensory effects
- Keyword
- Consumer demand responsiveness (CDR)
- Consumer demand responsiveness (CDR)
- Vent blockingBlocking of filter vents by lips or fingers
- Reward for effort
- Smoke direction
- Smoke swirl
- Smoke turbulence
- Vent blockingBlocking of filter vents by lips or fingers
- Strength attributes
- Taste enhancement
- Design Component
- Centre-jet filter
- CV filter
- Deep slot filter
- Experimental filter
- Grooved filter
- HH filter
- Slot filter
- Spin moulded filter
- TCT filter
- TTD filter
- Tube filter
- Tube-in-tow dual filter
- Turbulent filter
- Filter ventilation (Filter vents, air vents)
- Tube filter
- Actron filter
- Astra filter
- Filter efficiency (FE)
- Turbulent flow
- Operation/Project
- Project Kilt
- Named Organization
- BATCF, Hamburg
- Celanese
- Filtrona
- JT Inc.
- Technology/Method
- DELTA technique
- FIDES
- Glass mouth
- Spatial summation
- Subjective assessment
- Subject
- Compensation (Measures)
- Test/Consumer Preference (Testing)
- Smoke Delivery/Transport (Measures)
- Experimental Technology (Technology)
- Filters (Design)
- Low Yield Cigarettes (Products)
- Particle Size (Technology)
- Pressure Drop (Design)
- Puff Parameters (Measures)
- Sensory Effects—Taste (Effects)
- Sensory Effects—Impact (Effects)
- Test/Smoke Machine (Testing)
- Transfer to Smoke (Measures)
- Ventilation (Design)
- aerosol (technology)
- Brand
- Barclay
- Concord
Document Images
This report must not be copied or shown to unauthorised person~
B.A.T (U.K. & Export) Ltd.,
Research & Development Centre,
SOUTHAMPTON o
CCG/RA/46B-13
A REVIEW OF FILTERS WHICH GENERATE SMOKE
SWIRL, AND THEIR SENSORY PROPERTIES
REPORT NO. RD.2071 RESTRICTED
R&D-L019- 87
c.4
23.3.1987
AUTHOR: C.C. Greig
ISSUED BY: R.R. Baker
DISTRIBUTION:
Dr. R. Binns Copy No. 1
Mr. H.F. Dymond .... . 2
Mr. A.L. Heard .... 3,
Mr. M.L. Reynolds .... 4, 5
Dr. P.J. Dunn .... 6
Dr. S.R. Massey .... 7,
Mr. R.G. Nicholls .... 8, 9
Herr E. Rittershaus .... I0
Dr. E. Kausch .... ii
Dr. C.J.P. de Siqueira ....12
Mr. H.V. Thomsen .... 13
Mr. R.F. Gilderdale .... 14
Library .... 15, 16
COPY NO.
570365202
B.A.T (U.K. & Export) Ltd.,
Research & Development Centre,
SOUTHAMPTON.
CCG/RA/46B-13
23rd March, 1987
A REVIEW OF FILTERS WHICH GENERATE SMOKE SWIRL,
AND THEIR SENSORY PROPERTIES
REPORT NO. RD.2071 RESTRICTED
R&D-L019-87 c.4
SUMMARY
The history of swirl, beginning with the introduction of
ACTRON technology is reviewed and summarised, together with
the development of ACTRON PLUS. Evidence for the sensory
benefits Qf swirl is reviewed, together with a brief summary
of the findings of the 1984 Swirl Conference. The genesis of
Project KILT is described, as are the essential details of
its progress to date. Alternative approaches to swirl
generation are discussed, together with descriptions of the
modes of operation of these.
-i-
570365203
(~ 1987 B.A.T (U.K. and Export) I~m,ted. This report must not be copied or shown to unluthorised
persons.
KEY WORDS
Filters
Ventilated Filters
Experimental Filters
Turbulent Filters
Grooved Filters
ACTRON Filter
Spin Moulded Filters
Turbulent Flow
Mainstream Smoke Pattern
Smoke Direction
Smoke Turbulence
Smoke Swirl
Aerosol Particle Size
Subjective Assessment
Review
-ii-
5703 35204
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unau{hOnsed r>e,"~ons.
T
CONTENTS
A. SWIRL PRODUCTS
lo
Historical Developments
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
The ACTRON Filter
The BARCLAY Cigarette
Spatial Summation
The BARCLAY Controversy
ACTRON and ACTRON Plus
The Swirl Conference, 1984
What is Swirl?
Page
Bo
I.
J
SWIRL DEVELOPMENTS
Project KILT
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(i)
The Brief
Research into Turbulence
Candidate Designs
(a) Tube Filters
(b) Slot Filters
(c) Centre Jet Filters
(d) Laser Hole Filters
Cigarette Design Considerations
Consumer Subjective Testing -
Products and Small Scale
Consumer Subjective Testing - Larger Scale
Other BAT Group Developments
10
11
12
12
13
14
14
15
15
19
C.1 SUMMARY OF IN-HOUSE BAT SWIRL DEVELOPMENTS TODAY
(i)
(ii)
(iii)
(iv)
ACTRON
ACTRON Plus
KILTDevelopments
(a) 2-Tube Filters
(b) Deep Slot Filters
(c) Laser Hole Filters
(d) Injection Moulded
The HH Filters
20
20
21
21
21
21
21
21
D.I OTHER SWIRL FILTERS SIMILAR TO ACTRON IN CONCEPT
(i)
(ii)
(iii)
(iv)
The ASTRA Filters
The CV Filter
Other Filter Patents
Taste Enhancement by Filters
(a) TRUE
(b) Concord
23
23
24
24
24
24
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E.I OTHER BAT GROUP FILTER DEVELOPMENTS
(i) B&W, Louisville 25
(ii) BATCF, Hamburg 25
(iii) Other Laboratories 26
F.I
FUTURE DEVELOPMENTS
(i) FIDES and Swirl 26
(ii) Other KILT Possibilities 27
G.1 SUMMARY
Swirl - The Current Position
28
H.1 CONCLUSIONS 28
1.1 REFERENCES 30
J.1 APPENDIX - PATENTS 32
FIGURES
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INTRODUCTION
Up until about six years ago the majority of the filter work
of the BAT Group was to explore means of controlling smoke
components using filters. In the last few years the emphasis
has changed and much of the filter work has been associated
with designing filters which enhance the sensory properties
of smoke. A large part of this work has been in the design
of filters which cause the smoke to swirl as it emerges from
the filter and into the smoker's mouth. This swirling smoke
is associated with enhanced taste.
The objectives of the present review were to examine the
history of "swirl" filters, developed both within the BAT
Group and by others, to identify strengths and weaknesses
associated with particular designs, and to attempt thus to
assess how "swirl" may fit into future products.
A. THE HISTORY OF SWIRL
(i) The ACTRON Filter
Within the BAT Group, development of spinmoulding/grooving
of cellulose acetate filters occurred in the mid Ig7Os,
mainly in Southampton (1, 2). Once the base technology had
been established, emphasis in Southampton was put more onto
the high pressure drop/low efficiency concept of the HEE
filter (3) aimed at a level puff-by-puff profile, although
this was later abandoned. In Louisville, the technology was
translated into what became known as the ACTRON filter. In
this, four grooves, helically offset slightly for manufacturing
reasons, are impressed into a non-porous plugwrap paper of
the base filter rod by heat and pressure, forming the product
shown in Figure i. As can be seen, the four semicircular
grooves extend some 20 mm from the mouth end, allowing them
to be covered by the mechanically perforated tipping paper.
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-2-
Only mechanically and macrolaser perforated tipping can
allow the high local flow rates into the grooves to achieve
the high ventilation levels required for low deliveries. It
may be remarked in passing that, unlike conventional ventilated
filters, ACTRON has no upstream or downstream sections where
differing flows lead to differing filtration efficiencies
(4). Some second generation ACTRON filters do, however, have
upstream ventilation as discussed in Section (v) below.
(ii) The BARCLAY Cigarette
It is uncommon to find new cigarette brands which incorporate
more than one novel feature but, in the case of BARCLAY,
there were three at the initial launch:
.
35% expanded tobacco and very low (200 mg/ml) packing
density;
.
a blend nicotine of 3.0-3.2%, a full 1% or so more than
was conventional for low delivery blend nicotines at the
time; and
3. the most novel, the ACTRON filter.
A number Of marketing claims were made for BARCLAY at the
launch. Among these in some markets and of especial interest
in this Review was the topic of "spatial summation". This
has a chemosensory origin and is concerned with how stimuli
are perceived by humans - in this sense how smoke is perceived
in the smoker's mouth.
(iii) Spatial Summation
In the case of a given amount of smoke presented to a given
number of receptor sites, e.g. I mg into a standard human
570365208
(~) 1987 BAT I U.K. and Exponl Llm.¢d. This report must not be copied or shown to unauthonsed
per'sons.
-3-
mouth, if the time of presentation were to be long, i.e.
minutes, the total sensation would be expected to be of low
intensity but persistent. If, on the other hand, the
presentation time is short, i.e. milliseconds, the sensation
would be expected to be intense and shortlived. These become
known or learned human experiences, but they have a physical
and chemical rationale. The structure of the human chemosensory
system is complex but, at the lowest level, response is due
to the "firing" of neurons when activated by a stimulus to
which they are susceptible. The brain collates the origin
and intensity of the stimuli and gives a taste type and
intensity interpretation (which may or may not be acceptable).
"Spatial summation" is the term used when the highest number
of neurons can be caused to fire at the highest rate, i.e.
the given dose of smoke in this case has been caused to reach
as many active receptor sites as possible as fast as possible,
thus causing the maximum stimulus to the smoker.
Conventional unventilated cigarettes, when smoked at standard
conditions into a model "glass mouth", can be seen to give a
plume of smoke of the same diameter as the filter (see
Figure 2(a)). The smoke, due to its greater density than
air, tends to fall to the bottom of the mouth and, in a
human, would cover the tongue and fill the lower third or so
of the mouth.
Conventionally ventilated cigarettes, i.e. with ventilation
into the filter, emit a thinner stream of smoke, the width of
which is dependent upon the ventilation level - typically, at
80% ventilation, this is of the order of 1.5 to 2 mm diameter
(Figure 2(b)). (Visually, the size of the "bullseye" TPM
stain on the mouth end of the filter is a good guide to the
size of the smoke stream, since it is the smoke stream that
causes the "bullseye".)
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unau[.bx)nstd persons
• J
-4-
This thin stream of smoke travels in a "glass mouth" much as
for the conventional unventilated cigarette, though in the
B&W "glass mouth" it may even pass down the "model" trachea.
This is not a realistic human situation since it is known
that the trachea is closed during puffing and the actual act
of puffing is produced by the smoker "dropping" the bottom of
the mouth. In this case the thin stream of smoke may
occasionally impinge on the rear of the mouth, impact, reverse,
and return forwards, spreading out as it proceeds.
In BARCLAY, a completely different situation applies. Here,
the smoke stream and ventilating air streams are kept apart
until they exit from the cigarette. Owing to the volume of
ventilating air flow, 28 cm3 (80%) flowing through four
grooves of total area about 1.6 mm2, meeting 7 cm3 of smoke
flowing through an area of about 48 mm2, a vast speed
differential between the two streams is achieved.
The aerodynamics/fluid mechanics of such a system are amenable
to mathematical modelling, based on experience with the force
fields experienced in full-size aircraft and their engines
(5, 6) and at the Swirl Conference (7) a presentation clearly
demonstrates the degree of understanding now available via
this route.
In any "glass mouth", ACTRON shows (Figure 3) the vigorous
mixing of smoke and air predicted by modelling (8), and to
such a degree that all the internal surfaces become contacted
with smoke very swiftly after the start of the puff. Thus
the conditions for "spatial summation" are obeyed - the
given smoke input is dispersed to the maximum number of
sites in the minimum time. This has also been demonstrated
in human mouths by use of a fibre-optic light source/video
camera recording system.
It should be remembered that while "spatial summation"
maximises the initial effect of a given amount of smoke, it
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