Center heating cigarette temperature curve regulation and control method for improving smoke release stability

Abstract

A central heating cigarette temperature curve regulation and control method for improving smoke release stability is characterized in that a heating curve for heating a cigarette is subjected to periodic heating, that is, the cigarette is heated by a smoking set during smoking so that the cigarette can be kept at a relatively high temperature, and the relatively high temperature is subsequently called a first heating temperature; and in the smoking interval, the heating temperature of the smoking set is reduced, so that the cigarette is kept at a relatively low temperature, the relatively low temperature is subsequently called a second heating temperature, and the first heating temperature and the second heating temperature alternately appear. The device has the beneficial effects that the puff-by-puff smoke release stability in the smoking process of the heated cigarette can be effectively improved, the concentration of the smoke can be adjusted in a puff-by-puff mode, the adjusting mode is more flexible, the problems that the smoke consistency is not high and the stimulation feeling is high in the smoking process of the heated cigarette are solved, and the purposes that the smoke stability is kept, and the smoking quality is improved are achieved. And excessive release of irritant substances is avoided.

Description

Technical Field

[0001] The invention belongs to the field of heated cigarettes, and in particular relates to a temperature control method for centrally heated cigarettes which can improve smoke release stability. Background Art

[0002] In the research and development process of heated cigarettes, how to ensure the consistency of temperature, composition and flavor of each puff of smoke has become one of the core technical challenges for improving the smoking experience. The smoke of traditional cigarettes is produced by the burning of tobacco. As long as the tobacco is evenly filled in the cigarette, the smoke of each puff can achieve good consistency. Unlike traditional cigarettes, heated cigarettes are heated as a whole when producing smoke. If the heating temperature is too high in the early stage of smoking, too much substance will be released in the cigarette, and it will inevitably appear that the smoke is bland and tasteless in the later stage of smoking. In actual applications, the existing heating technology still has the instability of smoke release. Especially in the case of constant temperature heating, the key components of the smoke often show a release pattern of first rising and then falling, resulting in an uneven smoking experience.

[0003] In order to solve the problem of unstable smoke release, Philip Morris Manufacturing Co., Ltd. proposed a heated aerosol generating device and a method for generating aerosols with consistent characteristics (application number: 201380037681.2). The method of heating is first high temperature, then low temperature, and then high temperature. The core goal of this strategy is to quickly release low-volatile components at a higher temperature in the early stage to enhance the initial flavor and volume of the smoke; then, appropriately cool down in the middle stage to control the release of flavor substances and nicotine, avoid excessive release that causes the smoke to be bland and tasteless in the later stage, and thus maintain the balance and stability of the smoke in the later stage. In this way, the release pattern of the smoke can be optimized to ensure the consistency of flavor during the smoking process.

[0004] However, although this strategy can improve the stability of smoke to a certain extent, the influence of high-temperature heating on macromolecular substances in tobacco in the later stage may still lead to excessive release of these substances. This will not only increase the irritating components in the smoke and affect the comfort of smoking, but may also cause fluctuations in the flavor components in the smoke, resulting in inconsistent smoking experience. Therefore, how to balance the temperature changes during the heating process to maintain the stability of the smoke and avoid excessive release of irritating substances is still a difficult problem that needs to be solved in current technology. Summary of the invention

[0005] The purpose of the present invention is to provide a temperature control method for centrally heated cigarettes that improves smoke release stability, thereby solving the problem of weak smoke consistency and strong irritation during smoking of heated cigarettes.

[0006] The purpose of the present invention is achieved by adopting the following technical solutions: A method for controlling the temperature curve of a centrally heated cigarette for improving smoke release stability, wherein the heating curve of the heated cigarette is heated periodically, that is, during smoking, the smoking device heats the cigarette to keep it at a relatively high temperature, which is hereinafter referred to as the first heating temperature; and during the smoking interval, the heating temperature of the smoking device is reduced to keep the cigarette at a relatively low temperature, which is hereinafter referred to as the second heating temperature, and the first heating temperature and the second heating temperature appear alternately; To obtain the heating curve corresponding to the heated cigarette, the following steps are required: The first step is to conduct thermogravimetric analysis on the core material of the heated cigarette to obtain the thermal weight loss curve of the core material. The second step is to determine the first heating temperature and the second heating temperature. The first heating temperature is the temperature corresponding to the peak value of the second thermal weight loss peak of the thermal weight loss integral curve of the cigarette core material. The reason is that at this temperature, the release rate of key components in the cigarette core segment, such as propylene glycol, nicotine, glycerol, etc., is the largest. Using this temperature as the first heating temperature can ensure the rapid release of substances in the cigarette core segment.

[0007] The second heating temperature varies according to the different core materials used in the heated cigarettes. Specifically, it is the starting temperature of the first thermal weight loss peak of the core material. The reason is that when the core temperature is lower than this value, only a small amount of material is released. Using this temperature as the second heating temperature can reduce the amount of material released in the core during the non-smoking cycle, reduce waste, and avoid complete cooling of the core, reducing the time for re-heating.

[0008] The third step is to determine the first heating temperature and the second heating temperature duration. The first heating temperature duration is 10-15s, and the second heating temperature duration is 10-20s. The first heating temperature duration should be longer than the time it takes for the cigarette core segment to heat up to the first heating temperature. The sum of the first heating temperature duration and the second heating temperature duration is equal to the puffing interval; Through investigating the smoking habits of users and conducting experiments to measure the time for the temperature of the cigarette core section to rise from the second heating temperature to the first heating temperature, after determining the duration of the first heating temperature and the duration of the second heating temperature, they are alternately arranged and combined to obtain the first version of the heating curve, and then this temperature curve is used to heat the cigarette, and the stability of the smoke release of each puff is evaluated. According to the stability of the smoke release of each puff, it is adjusted. The evaluation index of the stability of the smoke release of each puff is the discrete degree of ACM (aerosol capture amount); The fourth step is to use the first version of the heating curve to smoke the cigarette made of the core material to obtain the ACM release in each puff of smoke. According to the release amount of each puff, the heating temperature of each puff is adjusted separately. The adjustment principle is that for those with less ACM release, the temperature can be appropriately increased, and for those with large ACM release, the temperature can be appropriately reduced. After adjustment, the second version of the heating curve is obtained. The temperature adjustment range is between 30°C and 70°C.

[0009] The beneficial effects of the present invention are that the stability of smoke release from each puff during the smoking process of heated cigarettes can be effectively improved, and the concentration of smoke can be adjusted puff by puff, and the adjustment method is more flexible, which solves the problems of weak smoke consistency and strong irritation during the smoking process of heated cigarettes, and achieves the purpose of maintaining smoke stability and avoiding excessive release of irritating substances.

[0010] The present invention also fully considers the influence of factors such as the time of puffing and the interval between puffs on the heating temperature curve. Compared with the prior art, the heating curve control method formulated pays more attention to balancing the temperature changes during the heating process, better maintaining the stability of the smoke, and thus improving the smoking comfort of the heated cigarette. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Flow chart of the method for controlling the temperature curve of a centrally heated cigarette to improve the stability of smoke release; Figure 2 It is a thermogravimetric curve diagram of thermogravimetric analysis of heated cigarette core material; In the figure: TG is the thermogravimetric curve, DTG is the differential thermogravimetric curve; Figure 3 This is the first version of the temperature curve; Figure 4 For a cigarette core Figure 3 The result analysis diagram of smoke release puff by puff is obtained by heating the heating curve; Figure 5 This is the second version of the temperature curve; Figure 6 For a cigarette core Figure 5 The heating curve is used to heat the smoke, and the result analysis chart of smoke release puff by puff is obtained. DETAILED DESCRIPTION

[0012] The present invention is further described below in conjunction with the accompanying drawings (embodiments): Example 1 Tobacco sheets made by a certain process are used as the material for heated cigarette cores. Thermogravimetric analysis is performed on them and the thermogravimetric curve is as follows: Figure 2 shown.

[0013] For this cigarette core material, it can be seen from the thermogravimetric curve that its second heating temperature should be 130°C and the first heating temperature should be 289.7°C.

[0014] According to the survey of users' smoking habits, most users have a smoking interval of 30s and a smoking time of 2s. According to experimental measurements, the cigarette core reaches the first heating temperature after 8s when heated at the first heating temperature. The first heating temperature duration is set to 10s, and the second heating temperature duration is set to 20s. Note: Only when the cigarette is at the first heating temperature, smoke is released when the cigarette is smoked, so the smoking time is within the first heating temperature duration period. For the convenience of users, the smoking device will vibrate when the first heating temperature duration reaches 6s, prompting the user to smoke. The first version of the temperature curve is as follows: Figure 3 shown.

[0015] Modify the heating curve of a smoking device to Figure 3 The curve is shown in FIG. 1 , and then the heated cigarette made of the cigarette core material is used to capture smoke puff by puff, and its ACM stability is analyzed. The analysis results are shown in FIG. Figure 4 shown.

[0016] from Figure 4 It can be seen that the amount of smoke released in the middle puffs is large, while the amount released in the first and last puffs is small, so the temperature of the first and last puffs is appropriately increased, and the temperature of the middle puffs is appropriately reduced. Here, adjustments are made based on the results of the experiment to explain the adjustment method. Different smoking utensils, different heating methods and different core materials will affect the release law. The second version of the temperature curve is as follows Figure 5 shown.

[0017] Modify the heating curve of the smoking device to Figure 5 The curve is shown in Figure 1. Then, the heated cigarette made of the cigarette core material is used to capture smoke puff by puff and analyze its ACM stability. The analysis results are shown in Figure 1. Figure 6 shown.

[0018] from Figure 6 It can be seen that the puff-by-puff smoke release stability has been significantly improved after adjustment.

Claims

1. A method for controlling the temperature curve of a centrally heated cigarette for improving smoke release stability, characterized in that: The heating curve of the heated cigarette adopts periodic heating, that is, when smoking, the smoking device heats the cigarette to keep it at a relatively high temperature, which is hereinafter referred to as the first heating temperature; and in the interval between smoking, the heating temperature of the smoking device is reduced to keep the cigarette at a relatively low temperature, which is hereinafter referred to as the second heating temperature, and the first heating temperature and the second heating temperature appear alternately; To obtain the heating curve corresponding to the heated cigarette, the following steps are required: The first step is to perform thermogravimetric analysis on the core material of the heated cigarette to obtain a thermogravimetric curve of the core material; The second step is to determine the first heating temperature and the second heating temperature. The first heating temperature is the temperature corresponding to the peak value of the second thermal weight loss peak of the thermal weight loss integral curve of the core material. The second heating temperature will vary to a certain extent according to the core material used in the heated cigarette, and is specifically the starting temperature of the first thermal weight loss peak of the core material; The third step is to determine the first heating temperature and the second heating temperature duration. The first heating temperature duration is 10-15s, and the second heating temperature duration is 10-20s. The first heating temperature duration should be longer than the time it takes for the cigarette core segment to heat up to the first heating temperature. The sum of the first heating temperature duration and the second heating temperature duration is equal to the puffing interval; Through investigating the smoking habits of users and conducting experiments to measure the time for the temperature of the cigarette core section to rise from the second heating temperature to the first heating temperature, after determining the duration of the first heating temperature and the duration of the second heating temperature, they are alternately arranged and combined to obtain the first version of the heating curve, and then this temperature curve is used to heat the cigarette, and the stability of the smoke release of each puff is evaluated. According to the stability of the smoke release of each puff, it is adjusted. The evaluation index of the stability of the smoke release of each puff is the discrete degree of ACM (aerosol capture amount); The fourth step is to use the first version of the heating curve to smoke the cigarette made of the cigarette core material to obtain the ACM release in each puff of smoke. According to the release amount of each puff, the heating temperature of each puff is adjusted separately. The adjustment principle is that for those with less ACM release, the temperature can be appropriately increased, and for those with more ACM release, the temperature can be appropriately lowered. After adjustment, the second version of the heating curve is obtained.

2. The temperature curve control method according to claim 1, characterized in that: In the second step, the first heating temperature is set to the temperature corresponding to the peak value of the second thermal weight loss peak of the thermal weight loss integral curve of the core material because at this temperature, the release rate of key components in the core segment, such as propylene glycol, nicotine, and glycerol, is the largest. Using this temperature as the first heating temperature can ensure the rapid release of substances in the core segment.

3. The temperature curve control method according to claim 1, characterized in that: In the second step, the second heating temperature is set as the starting temperature of the first thermal weight loss peak of the core material because when the temperature of the core segment is lower than this value, only a small amount of material is released; using this temperature as the second heating temperature can reduce the amount of material released in the core segment during the non-smoking cycle, reduce waste, and avoid complete cooling of the core segment, reducing the time for reheating.

4. The temperature curve control method according to claim 1, characterized in that: In the fourth step, the temperature is adjusted within the range of upper 30°C and lower 70°C.

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