Method for detecting the degree of tobacco sheet material liquid permeation and application thereof

Abstract

This invention provides a method for detecting the penetration degree of tobacco flakes, comprising the following steps: acquiring spectral data of a tobacco flake substrate without applied tobacco liquid and spectral data of the applied tobacco liquid using spectral imaging, and determining characteristic marker peaks for characterizing tobacco liquid penetration based on the spectral differences between the two; slicing the tobacco flakes after applying the tobacco liquid to obtain a cross-section containing the area where the tobacco liquid was applied; scanning the cross-section of the tobacco flakes using spectral imaging to obtain spectral-image data of the cross-section; analyzing and processing the spectral-image data based on the characteristic marker peaks to extract the distribution information of the tobacco liquid on the cross-section of the tobacco flakes; determining the penetration depth of the tobacco liquid inside the tobacco flakes based on the distribution information, and calculating the ratio of the penetration depth to the thickness of the tobacco flakes to obtain the tobacco liquid penetration ratio. This invention enables quantitative detection of the tobacco liquid, effectively solving the problem of detecting tobacco liquid penetration and significantly reducing the time and labor costs of detection.

Description

Technical Field

[0001] This invention relates to the field of cigarette manufacturing, specifically to a method for detecting the penetration of cigarette feed liquor and its application, and more particularly to a method for detecting and evaluating the penetration depth and penetration ratio of sheet cigarette feed liquor based on spectral imaging technology and its application. Background Technology

[0002] Adding additives to tobacco sheets is one of the core processes in cigarette manufacturing. Its main task is to uniformly apply the formulated liquid additives to the surface of the tobacco sheets to enhance aroma and moisture retention, improve the sensory quality of the tobacco sheets, and increase the stability of the cigarette product. The uniformity of the liquid additive application and its effective absorption in the tobacco leaves directly affect the utilization rate of the liquid additives, the consistency of product quality, and the control of cigarette production costs.

[0003] The key to improving the utilization rate of slurry lies in enhancing its penetration ability within the tobacco leaf tissue. However, due to the thinness of tobacco leaves (usually around 100 μm), the complexity of tobacco leaf tissue structure, and the diverse composition and viscosity differences of slurry, there is currently a lack of technical means to accurately and intuitively evaluate the degree of slurry penetration within the tobacco leaf.

[0004] In existing technologies, the evaluation of the absorption effect of the feed liquid mainly relies on indirect analytical methods, such as adsorption-desorption-thermogravimetric analysis, infrared thermography, and gas chromatography-mass spectrometry (GC-MS). While these methods can reflect the overall amount of feed liquid applied or the amount remaining on the surface at a macroscopic level, they cannot achieve in-situ, visual characterization of the penetration depth and distribution pattern of the feed liquid on the cross-section of the tobacco leaf, nor can they quantify the proportional relationship between the penetration depth of the feed liquid and the thickness of the tobacco leaf (i.e., the penetration ratio). In addition, the above methods generally suffer from drawbacks such as complex sample pretreatment, long detection cycle, high operating cost, and difficulty in meeting the needs of online or rapid detection.

[0005] Therefore, how to establish a method that can intuitively, quantitatively, and efficiently characterize the degree of penetration of the liquid into tobacco flakes has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a method for detecting the penetration degree of tobacco liquid and its application, which solves at least one of the problems mentioned in the background art.

[0007] In a first aspect, the present invention provides a method for detecting the penetration degree of tobacco powder liquid, comprising the following steps: (a) Spectral data of the tobacco substrate without applied liquid and spectral data of the liquid to be applied are obtained by using spectral imaging method, and characteristic marker peaks for characterizing liquid penetration are determined based on the spectral differences between the two. (b) Slice the tobacco flakes after the application of the slurry to obtain a cross-section of the tobacco flakes containing the area where the slurry was applied; (c) The cross-section of the tobacco sheet is scanned using a spectral imaging method to obtain spectral-image data of the cross-section; (d) Based on the characteristic marker peaks, the spectral-image data is analyzed and processed to extract the distribution information of the liquid material on the cross-section of the tobacco sheet; (e) Determine the penetration depth of the liquid inside the tobacco sheet based on the distribution information, and calculate the ratio of the penetration depth to the thickness of the tobacco sheet to obtain the liquid penetration ratio.

[0008] In a second aspect, the present invention provides an application of the above-described detection method in optimizing the application process of liquid additives or controlling product quality during the cigarette manufacturing process.

[0009] The present invention has at least the following beneficial effects: This invention addresses the detection of liquid penetration in tobacco leaves (e.g., in industrial enterprises) by employing infrared spectroscopy imaging to determine the degree of liquid penetration. Compared to other detection methods such as adsorption-desorption-pyrolysis, infrared imaging, and chemical analysis (GC-MS), this invention enables quantitative detection of the liquid, effectively solving the problem of liquid penetration detection in industrial enterprises and significantly reducing time and labor costs. Attached Figure Description

[0010] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0011] Figure 1 This is an infrared spectrum curve of tobacco leaves (sheet tobacco) and liquid feed in an embodiment of the present invention; Figure 2 This is an image obtained by visualizing the infrared spectrum of a tobacco leaf sample after the application of the filtrate and allowing it to stand for 0.5 h in an embodiment of the present invention. Figure 3 This is an image obtained by visualizing the infrared spectrum of a tobacco leaf sample after the application of the filtrate and allowing it to stand for 2 hours in an embodiment of the present invention. Figure 4 The image obtained by visualization processing of the infrared spectrum of the tobacco sample after the application of the liquid material and standing for 5 hours in this embodiment of the invention. Detailed Implementation

[0012] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0013] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form includes the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0014] It should be noted that if the text uses terms such as "first" or "second", these terms are only used to distinguish similar objects and should not be interpreted as indicating or implying their relative importance, order of precedence, or implicitly indicating the number of technical features indicated. It should be understood that the data in the descriptions of "first" and "second" can be interchanged where appropriate.

[0015] Throughout the accompanying drawings, identical elements are represented by the same or similar reference numerals. Conventional structures or configurations may be omitted where they might cause confusion in understanding the invention. Furthermore, the shapes, dimensions, and positional relationships of the components in the drawings do not reflect actual size, scale, or actual positional relationships. Additionally, any reference symbols placed within parentheses in this invention should not be construed as limiting the scope of the invention.

[0016] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] One aspect of the present invention provides a method for detecting the penetration degree of tobacco powder liquid, comprising the following steps: (a) Spectral data of the tobacco substrate without applied liquid and spectral data of the liquid to be applied are obtained by using spectral imaging method, and characteristic marker peaks for characterizing liquid penetration are determined based on the spectral differences between the two. (b) Slice the tobacco flakes after the application of the slurry to obtain a cross-section of the tobacco flakes containing the area where the slurry was applied; (c) The cross-section of the tobacco sheet was scanned using a spectral imaging method to obtain spectral-image data of the cross-section; (d) Based on the characteristic marker peaks, the spectral-image data is analyzed and processed to extract the distribution information of the liquid material on the cross-section of the tobacco sheet; (e) Determine the penetration depth of the liquid inside the tobacco sheet based on the distribution information, and calculate the ratio of the penetration depth to the thickness of the tobacco sheet to obtain the liquid penetration ratio.

[0018] The method of this invention, through spectral imaging technology combined with cross-sectional slice analysis, can quantitatively and visually characterize the degree of penetration of the feed liquid into the tobacco leaf, overcoming the shortcomings of traditional detection methods that can only assess surface adhesion and cannot reflect internal penetration. This method provides an objective and accurate evaluation tool for optimizing tobacco leaf feeding processes.

[0019] In some embodiments, the method for determining the characteristic marker peak in step (a) includes: comparing and analyzing the spectral data of the tobacco substrate and the spectral data of the liquid, and selecting one or more bands where the absorption peaks of the two differ significantly as characteristic marker peaks. For example, if the liquid has characteristic absorption in a specific infrared band while the tobacco substrate has weak absorption or no absorption in that band, then that band can be used as the characteristic marker peak; and vice versa. By selecting bands with significant differences, the detection signal-to-noise ratio and specificity can be maximized.

[0020] In some embodiments, the method for obtaining the cross-section of the tobacco sheet in step (b) is as follows: the area where the liquid is applied is vertically cut using a sharp cutting tool (such as a blade, slicer, etc.), with the cutting direction perpendicular to the surface of the tobacco sheet. To ensure the flatness and representativeness of the cross-section, it is preferable to cut at the center of the area where the liquid is applied. During cutting, squeezing or pulling of the tobacco sheet tissue should be avoided to prevent the illusion of liquid migration.

[0021] In some embodiments, before the spectral imaging scan in step (c), a clamping device is used to fix the sliced ​​tobacco sample, ensuring that the cross-section of the tobacco is perpendicular to the measurement optical path of the spectral imaging system and parallel to the surface of the clamping device. The clamping device can be made of lightweight materials (such as polytetrafluoroethylene, aluminum, etc.) to avoid contamination or damage to the sample. Precise fixation ensures geometric consistency for each scan and improves measurement repeatability.

[0022] In some embodiments, step (d) of analyzing and processing the spectral-image data to extract the distribution information of the liquid material on the cross-section of the tobacco sheet further includes: The spectral-image data is scanned line by line, and the peak area (such as the integrated area of ​​the absorption peak, peak height or peak intensity, etc.) of each line of the spectral curve under the characteristic marked peak is calculated. The calculated peak area is normalized to eliminate signal differences caused by factors such as light source intensity fluctuations and sample surface unevenness. Based on the normalized data, the spectral-image data is inverted to generate a visual distribution map of the liquid feedstock across the cross-section of the tobacco sheet. This distribution map can be encoded in pseudo-color to intuitively display the penetration path, distribution range, and concentration gradient of the liquid feedstock within the tobacco sheet.

[0023] In some embodiments, the step of extracting liquid distribution information further includes: using digital image processing technology to extract the regional location and corresponding pixel depth of the liquid distribution from the visualized distribution map based on color differences. For example, algorithms such as threshold segmentation and edge detection can be used to automatically identify the liquid penetration front and calculate the maximum depth, average depth, or specific quantile depth of the penetration area.

[0024] In some embodiments, in step (e), the pixel depth of the liquid distribution is proportionally converted to the pixel ratio of the tobacco thickness, and the liquid penetration ratio is calculated according to the following formula I: Liquid penetration ratio = (liquid penetration depth / tobacco thickness) × 100% I.

[0025] The liquid-to-powder penetration ratio is used to evaluate the penetration performance of liquids under different formulations, application processes, or settling times. For example, by comparing the penetration ratios of liquids with different viscosities, formulations with better penetration can be selected; or by comparing the penetration ratios under different application pressures and temperatures, application process parameters can be optimized. The liquid-to-powder penetration ratio is a core indicator for evaluating the ability of liquids to penetrate into the tobacco sheet. The higher the value, the easier it is for the liquid to penetrate into the tobacco sheet, and the better the penetration performance of the liquid.

[0026] In some embodiments, the spectral imaging method may be selected from any one of infrared spectral imaging, Raman spectral imaging, hyperspectral imaging, or terahertz spectral imaging. Different spectral techniques have different resolutions, penetration depths, and molecular specificities, and those skilled in the art can make appropriate selections based on the composition of the feed liquid, the characteristics of the tobacco matrix, and the required detection accuracy.

[0027] In some embodiments, the tobacco flakes are placed in a constant temperature and humidity environment for equilibration before the application of the feed solution. The parameters of the constant temperature and humidity environment are set as follows: relative humidity 60-80%, for example 62%, 65%, 68%, 70%, 72%, 75%, 78%, etc.; temperature 23-27℃, for example 24℃, 25℃, 26.4℃, etc.; and equilibration time 36-60 h, for example 40 h, 45 h, 50 h, 56 h, etc. Through equilibration treatment, the influence of the moisture difference of the tobacco flakes on the penetration behavior of the feed solution can be eliminated, making the test results more comparable and repeatable.

[0028] In some embodiments, the feed solution is applied by quantitative dripping, with an application volume of 20-100 μL, such as 25 μL, 33 μL, 50 μL, 62 μL, 70 μL, 90 μL, etc.; after application, it is allowed to stand for 0.5-5.0 h, such as 0.6 h, 1.0 h, 1.7 h, 2.5 h, 3.0 h, 3.7 h, 4.2 h, 4.8 h, etc., before slicing. The length of the standing time directly affects the penetration depth of the feed solution; by setting different standing times, the permeation kinetics can be studied.

[0029] Another aspect of the present invention provides an application of the above-mentioned detection method in the optimization of the liquid application process or product quality control during the cigarette manufacturing process. By embedding this detection method into the cigarette manufacturing production line, online monitoring or offline sampling inspection of the feeding process can be achieved, timely detection of poor penetration problems can be made, and process parameters can be adjusted, thereby improving the sensory quality and batch stability of cigarette products.

[0030] The technical solution of the present invention will be described in detail below through specific embodiments, but the present invention is not limited to the following embodiments.

[0031] Example 1 A method for detecting the penetration degree of tobacco powder liquid is provided, and the specific steps are as follows: Sample preparation and equilibration: Take tobacco flakes from the same batch that have not been treated with liquid and place them in a constant temperature and humidity chamber. Set the relative humidity to 70% and the temperature to 25℃ and equilibrate for 48 hours.

[0032] Characteristic peak identification: Fourier transform infrared spectroscopy (FTIR) was used to collect infrared spectral data of the tobacco substrate and the liquid to be applied (a certain brand of tobacco additive). Figure 1 Infrared spectral curves of tobacco leaves (sheet tobacco) and slurry in this embodiment are provided. (Comparison) Figure 1 The spectra revealed that the two were at 837 cm⁻¹ -1 The differences are significant, therefore, 837 cm was used. -1 As a characteristic marker peak.

[0033] Application of the liquid: Use a micropipette to add 50 μL of liquid to the center of the equilibrated tobacco surface. After application, let stand for 0.5 h to allow the liquid to penetrate naturally.

[0034] Slicing and Fixation: After settling, slice the tobacco sheet along the area where the feed liquid was applied using a sharp blade to obtain a thin cross-sectional slice of the applied feed liquid area. Clamp the sliced ​​sample with an aluminum sheet to ensure that the cross-section of the tobacco sheet is perpendicular to the measurement optical path, while keeping the cross-section of the tobacco sheet parallel and aligned with the aluminum sheet to ensure the uniformity of the measurement surface.

[0035] Spectral imaging scanning: An infrared microscopic imaging system equipped with a focal plane array detector is used to perform surface scanning on the cross-section of the tobacco leaf to obtain spectral-image data of the cross-section.

[0036] Data Processing and Distribution Visualization: The spectral imaging data is scanned line by line, and the peak area under the characteristic peak of each spectral curve is calculated. The peak areas are normalized, and a visualization method is used to invert the spectral imaging data to obtain a visualization of the liquid content in the cross-section of the tobacco leaf, which is used to extract liquid content distribution information. Specifically: an 837cm² image is used. -1 As marker peaks, infrared spectral data are processed, peak areas under characteristic peaks are calculated and normalized, and then processed using visualization methods (using matpltlib, cmap='jet') to obtain color images, such as... Figure 2 As shown.

[0037] Penetration depth measurement and penetration ratio calculation: Digital image technology was used to extract the location information of the liquid distribution based on color differences. This information was then proportionally converted to the tobacco leaf thickness. The penetration ratio was calculated using Formula I, based on the pixel ratio of the liquid distribution depth to the tobacco leaf thickness. Specifically, the pixel ratios of the tobacco leaf and liquid were extracted according to the different color distributions in the cross-section. The spectral imaging data was 960*64 pixels (length*width) with 1019 bands. Each pixel represented 1 μm. The calculated penetration ratios are shown in Table 1 below.

[0038] Example 2 The method is basically the same as in Example 1, except that the settling time is adjusted to 2 hours. Figure 3 The image shown is an image obtained by visualization processing of the infrared spectrum of the tobacco sample after the application of the feed solution and standing for 2 hours in this embodiment. The results of the permeability ratio calculated in this embodiment are shown in Table 1 below.

[0039] Example 3 The method is basically the same as in Example 1, except that the settling time is adjusted to 5 hours. Figure 4 The image shown is an image obtained by visualization processing of the infrared spectrum of the tobacco sample after the application of the feed solution and 5 hours of settling. The results of the permeability calculated in this embodiment are shown in Table 1 below.

[0040] Table 1

[0041] The results in Table 1 visually reflect the effect of settling time on the penetration depth, indicating that the detection method of the present invention can effectively distinguish the penetration differences under different process conditions.

[0042] The above embodiments successfully achieved quantitative detection of the degree of penetration of the liquid into the tobacco leaf. The penetration ratio results were consistent with the trend observed visually, verifying the feasibility of the method.

[0043] The detection method of this invention utilizes the difference in absorption / reflection spectra of characteristic components of tobacco and tobacco liquor in a specific wavelength band. Through cross-sectional imaging analysis, it achieves for the first time a quantitative characterization of the ratio of liquor penetration depth to tobacco thickness (i.e., liquor penetration ratio). This provides a new and rapid detection method for optimizing cigarette feeding processes, designing liquor formulations, and controlling product quality.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting the penetration degree of tobacco powder liquid, characterized in that, Includes the following steps: (a) Spectral data of the tobacco substrate without applied liquid and spectral data of the liquid to be applied are obtained by using spectral imaging method, and characteristic marker peaks for characterizing liquid penetration are determined based on the spectral differences between the two. (b) Slice the tobacco flakes after the application of the slurry to obtain a cross-section of the tobacco flakes containing the area where the slurry was applied; (c) The cross-section of the tobacco sheet is scanned using a spectral imaging method to obtain spectral-image data of the cross-section; (d) Based on the characteristic marker peaks, the spectral-image data is analyzed and processed to extract the distribution information of the liquid material on the cross-section of the tobacco sheet; (e) Determine the penetration depth of the liquid inside the tobacco sheet based on the distribution information, and calculate the ratio of the penetration depth to the thickness of the tobacco sheet to obtain the liquid penetration ratio.

2. The detection method according to claim 1, characterized in that, In step (a), the method for determining the characteristic marker peaks includes: comparing and analyzing the spectral data of the tobacco substrate and the spectral data of the liquid material, and selecting one or more bands with significant differences in absorption peaks between the two as characteristic marker peaks; Preferably, in step (b), the cross-section of the tobacco sheet is obtained by using a sharp cutting tool to vertically cut the area where the liquid is applied, with the cutting direction perpendicular to the surface of the tobacco sheet.

3. The detection method according to claim 1 or 2, characterized in that, In step (c), before the spectral imaging scan, a clamping device is used to fix the sliced ​​tobacco sample so that the cross-section of the tobacco is perpendicular to the measurement optical path of the spectral imaging system and the cross-section is parallel and aligned with the surface of the clamping device.

4. The detection method according to any one of claims 1 to 3, characterized in that, In step (d), the spectral-image data is analyzed and processed to extract the distribution information of the liquid material on the cross-section of the tobacco sheet, including: The spectral-image data is scanned line by line, and the peak area under the characteristic marked peak is calculated for each line of the spectral curve. The calculated peak area is then normalized. Based on the normalized data, the spectral-image data is inverted to generate a visual distribution map of the liquid material on the cross-section of the tobacco sheet.

5. The detection method according to claim 4, characterized in that, The step of extracting liquid distribution information further includes: using digital image processing technology to extract the regional location and corresponding pixel depth of liquid distribution from the visualized distribution map based on color differences.

6. The detection method according to any one of claims 1 to 5, characterized in that, In step (e), the pixel depth of the liquid distribution is proportionally converted to the pixel ratio of the tobacco thickness, and the liquid penetration ratio is calculated according to the following formula I: Liquid penetration ratio = (liquid penetration depth / tobacco thickness) × 100%I.

7. The detection method according to any one of claims 1 to 6, characterized in that, The spectral imaging method is any one of infrared spectral imaging, Raman spectral imaging, hyperspectral imaging, or terahertz spectral imaging.

8. The detection method according to any one of claims 1 to 7, characterized in that, Before applying the molten material, the tobacco flakes are placed in a constant temperature and humidity environment for equilibration. The parameters of the constant temperature and humidity environment are set as follows: relative humidity 60-80%, temperature 23-27℃, and equilibration time 36-60 h.

9. The detection method according to any one of claims 1 to 8, characterized in that, The material solution is applied by quantitative dripping, with an application volume of 20-100 μL. After application, the solution is allowed to stand for 0.5-5.0 h before slicing.

10. The application of the detection method as described in any one of claims 1 to 9 in the optimization of the liquid application process or the control of product quality during the cigarette manufacturing process.

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