Tobacco Documents Online

Draft of general outline on aspects of cigarette design. Notes cigarette design has objectives of: 1) controlling deliveries to acceptable levels, 2) optimizing smoking mechanics, 3) providing acceptable physical properties, and 4) providing acceptable visual properties. Describes "tools" at disposal of designer, which include computerized cigarette design model, analytical data, standard nontobacco materials, blend components, processes (pressure drop, density, etc.), smoke sensory quality assessment, and sensory input. Notes that cigarette design influences taste perception as blend and flavors do, and should be considered in combination with these factors. Gives detailed outline of steps in developing a product, including production, assessment, and ultimately commercialization.

Discusses effects of free nicotine on smoke impact. "Smoke impact is defined as "smoker's degree of awareness of the presence of tobacco smoke in the back of the throat." Describes model for smoke impact through receptors activated at back of throat. Claims the degree of smoke impact is determined by the amount of free nicotine in the smoke. Notes that free nicotine depends on smoke pH and total nicotine. While total nicotine represents the potential nicotine available to the smoker, it does not represent the free nicotine that is actually available "since the smoker is unable to employ strong bases in order to liberate all the nicotine, that is, at least not in his mouth." Concludes that it should be possible to "create an ultra-low tar cigarette that produces much more impact than its delivery would suggest."

Discusses (and provides equations for calculating) effects of paper permeability, filter ventilation, circumference, and puff position on delivery. Defines porosity (fraction of open space in a material), permeability (measure of the ability of a material to allow a fluid to pass through it), CORESTA permeability and conversion to Filtrona and Greiner permeability ratings. Describes relationship between cigarette parameters and ventilation, including pressure drop, tipping permeability, rod length and width, tipping paper vent area, circumference, cut width, and denier per filament. Graphs show effects of ventilation on puff count and tar/nicotine ratio. Ventilation reduces pressure drop and tar delivery, increases nicotine content of TPM, and reduces carbon monoxide delivery.

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.

Review of theory on the interaction between smoker and cigarette. Hypothesizes that while nicotine is responsible for sensory effects, it is other compounds in cigarette smoke and design parameters of cigarette that modulate how the smoker delivers nicotine to herself. Discusses possible measures for physiological response, focusing on puff profile, amount of smoke that is "wasted" after the puff is taken, and the characteristics of the first inhalation after the puff. Suggests use of these measures to improve marketplace performance and directly effect product construction/design. Analyzes degree to which measurements can be made accurately, degree to which these behaviors are influenced by habit, determinants of behavior, and predictive ability of measures (alone or in combination). Provides recommendations for future research.

Describes how variations in product delivery modification affect smoker compensation. Notes that in addition to nicotine, the amount of smoke/puff or perceived level of taste may effect compensation. Suggests two approaches for design of low delivery cigarettes: 1) reducing deliveries of gas phase components (appropriate for those smokers who do not compensate); and 2) reduction of tar and gas phase components relative to nicotine (assuming nicotine drives compensation.) Notes that the altered T/N cigarette "would have somewhat different taste characteristics from current products." Recommends further research into the interaction between the smoker and altered design products. Notes minimum nicotine intake of 1 mg may be necessary for certain pharmacological effects.

Report summarizing study to determine changes in human smoking parameters for cigarettes with altered nicotine deliveries and similar tar, CO, and RTD (resistance to draw) parameters. Describes significant differences in puff duration, puff interval, and mean smoke volume due to altered nicotine, with increases in nicotine resulting in increased puff interval and decreases in puff number, volume and duration. Notes delivery changes associated with puff parameter changes "appear to be very minimal". Concludes that it is not clear whether parameter changes are a result of pharmacological responses to nicotine or response to taste/strength differences in the cigarette.