Method for evaluating physical properties of paper-making reconstituted tobacco sheet base

Abstract

The invention relates to a method for evaluating the physical performance of a paper-making reconstituted tobacco sheet base, and belongs to the technical field of reconstituted tobacco performance evaluation. The method comprises the following steps: detecting physical performance indexes of paper-making process reconstituted tobacco base samples with different raw material ratios and different pulping processes; screening physical performance indexes of the reconstituted tobacco base sample by taking preset tensile strength, softness and absorbability as targets; carrying out normalization processing on physical performance indexes of the screened reconstituted tobacco base sample, and then carrying out Spearman correlation analysis; carrying out entropy method weight analysis on the physical performance indexes of the screened reconstituted tobacco sheet base samples, and establishing a paper-making process reconstituted tobacco sheet base physical performance evaluation model; and evaluating the physical properties of the to-be-evaluated paper-making process reconstituted tobacco sheet base by using the paper-making process reconstituted tobacco sheet base physical property evaluation model. The quantitative and effective evaluation method is established for the physical properties of the reconstituted tobacco base.

Description

Technical Field

[0001] This invention relates to a method for evaluating the physical properties of reconstituted tobacco leaves produced by papermaking, belonging to the technical field of reconstituted tobacco leaf performance evaluation. Background Technology

[0002] Reconstituted tobacco (hereinafter referred to as "reconstituted tobacco") is a reconstituted tobacco product made from tobacco by-products such as tobacco stems and tobacco scraps. It is produced using the wet papermaking process, involving extraction, pulping, papermaking, coating, and drying. Compared to natural tobacco leaves, reconstituted tobacco has advantages such as a looser structure, adjustable physicochemical properties, and unique characteristics. It plays a significant role in reducing tar and harmful substances while also being less expensive, thus becoming an indispensable and important component of raw materials for Chinese-style cigarettes.

[0003] Reconstituted tobacco leaf substrate serves as a crucial intermediate carrier for pulp and finished products, and its performance directly impacts production efficiency and product quality. In the production practice of reconstituted tobacco enterprises, the determination of physical performance indicators mostly relies on standard methods for papermaking. Although the raw materials and processing technology of reconstituted tobacco are similar to those of papermaking, there are significant differences in their physical properties and requirements. Consequently, many relevant physical indicators and measurement methods are not applicable. Therefore, it is necessary to select evaluation indicators suitable for the physical properties of reconstituted tobacco.

[0004] Currently, numerous reports exist on testing standards and methods for physical indicators of reconstituted tobacco leaves, such as basis weight, thickness, tensile strength, and softness. Patents CN201610384220.8 and CN201610231512.8S01, respectively, combine known samples to determine the basis weight of irregularly shaped reconstituted tobacco leaves through paper quality and basis weight measurement, as well as image capture. Patent CN202410759861.1 calculates the thickness of reconstituted tobacco leaves based on laser stripe images using an image processing unit. Patent CN202010397331.9K1 uses a tensile strength tester to stretch strip-shaped reconstituted tobacco leaf samples by adjusting the clamp position, obtaining the actual measured value of the tensile strength of the reconstituted tobacco leaves. Patent CN201910701761.2 uses a physical property analyzer to calculate the softness of the sample under test based on the maximum stress. Patent CN202310492611.1 calculates the softness HF of reconstituted tobacco samples by acquiring surface roughness TS750, fiber true softness TS7, and paper sinking distance D data. Patent CN201910734614.5 characterizes the absorbency of a sample by the liquid absorption mass per unit absorbent area.

[0005] However, the above reports mainly focus on the measurement methods of individual physical indicators of reconstituted tobacco leaves, and have not yet systematically integrated the comprehensive physical properties of reconstituted tobacco leaves, nor have they explored the correlation between physical indicators. Currently, the physical properties of reconstituted tobacco leaves are evaluated more by visual observation and touch, and subjective factors have a strong influence on the results. Summary of the Invention

[0006] To address the problems of limited physical performance indicators and strong subjective interference in existing papermaking-based reconstituted tobacco leaf samples, this invention proposes a method for evaluating the physical performance of papermaking-based reconstituted tobacco leaf substrates. The method involves normalizing the physical performance indicators of selected reconstituted tobacco leaf substrate samples and performing Spearman correlation analysis. Entropy value analysis is then used to weight the selected physical performance indicators, establishing an evaluation model for the physical performance of papermaking-based reconstituted tobacco leaf substrates. This model is then used to evaluate the physical performance of the papermaking-based reconstituted tobacco leaf substrates to be evaluated. This invention establishes a quantitative and effective evaluation method for the physical performance of reconstituted tobacco leaf substrates.

[0007] A method for evaluating the physical properties of reconstituted tobacco leaf substrate produced by papermaking, comprising the following specific steps: (1) Test the physical properties of papermaking reconstituted tobacco leaf samples with different raw material ratios and different pulping processes; the physical properties include basis weight, thickness, tensile strength, softness, air permeability and absorbency. (2) Screening of physical performance indicators for reconstituted tobacco leaf substrate samples with preset tensile strength, softness and absorbency as targets; (3) The physical performance indicators of the selected reconstituted tobacco leaf samples were normalized and then Spearman correlation analysis was performed. (4) Perform entropy weight analysis on the physical performance indicators of the selected reconstituted tobacco leaf samples and establish a physical performance evaluation model for papermaking reconstituted tobacco leaf samples. (5) The physical properties of the paper-made reconstituted tobacco leaf substrate to be evaluated are evaluated using the paper-making reconstituted tobacco leaf substrate evaluation model.

[0008] Preferably, in step (1), the proportions of different raw materials are different for stem pulp, leaf pulp, and wood pulp.

[0009] Preferably, step (2) has a preset tensile strength of 0.30~0.60kN / m, a softness of ≤300mN, and an absorbent liquid height of ≥25mm.

[0010] Preferably, the specific method for normalization in step (3) is as follows: using a normalization formula, the physical performance data of the reconstituted tobacco leaf sample are linearly mapped to the [0,1] interval; the normalization formula is: ； In the formula: X normalized The new data is normalized, and X is the original data. min X is the minimum value of this physical performance index. max This is the maximum value of the physical performance index.

[0011] Preferably, the specific method for Spearman correlation analysis in step (3) is as follows: The normalized reconstituted tobacco leaf sample data of each physical performance index were converted into grades and sorted. The grade difference d and the square of the grade difference d for each physical performance index were calculated. 2 Calculate the Spearman rank correlation coefficient.

[0012] More preferably, the formula for calculating the Spearman rank correlation coefficient is: ; In the formula, ρ is the Spearman rank correlation coefficient, which ranges from [-1, 1], and n is the number of samples.

[0013] Preferably, step (4) involves performing entropy-based weight analysis on the physical performance indicators of the screened reconstituted tobacco leaf substrate samples to establish a physical performance evaluation model for the papermaking reconstituted tobacco leaf substrate. The specific method is as follows: 1) Calculate the proportion of the i-th reconstituted tobacco leaf sample to the j-th physical performance index in the reconstituted tobacco leaf sample; 2) Calculate the information entropy value of the j-th physical performance index in the reconstituted tobacco leaf sample; 3) Calculate the information utility value d of the j-th physical performance index in the reconstituted tobacco leaf sample. j And the weighting coefficient of the j-th physical performance index in the reconstituted tobacco leaf sample; 4) Establish a physical performance evaluation model for reconstituted tobacco leaf substrate made by papermaking.

[0014] Preferably, in step 1), the proportion of the i-th reconstituted tobacco leaf substrate sample to the j-th physical performance index in the reconstituted tobacco leaf substrate sample is calculated using the following formula: ; In the formula, P ij X represents the proportion of the j-th physical performance index of the i-th reconstituted tobacco leaf substrate sample to that physical performance index. ij Let be the j-th physical performance index in the i-th reconstituted tobacco leaf sample, and n be the number of reconstituted tobacco leaf samples. Step 2) The information entropy value of the j-th physical performance index in the reconstituted tobacco leaf sample is calculated using the following formula: ; In the formula, e j To determine the information entropy value of the j-th physical performance index in the reconstructed tobacco leaf sample, P ij The weight of the i-th reconstituted tobacco leaf sample relative to the j-th physical performance index in the reconstituted tobacco leaf sample is denoted by n, where n is the number of reconstituted tobacco leaf samples. Step 3) The information utility value d of the j-th physical performance index in the reconstituted tobacco leaf substrate sample j The calculation formula is: d j =1-e j ; In the formula, d j e represents the information utility value of the j-th physical performance index in the reconstituted tobacco leaf sample. j The information entropy value of the j-th physical performance index in the reconstituted tobacco leaf sample; Step 3) The weighting coefficient of the j-th physical performance index in the reconstituted tobacco leaf sample is calculated using the following formula: ; In the formula, W j d represents the weighting coefficient of the j-th physical performance index in the reconstituted tobacco leaf sample. j The information utility value of the j-th physical performance index in the reconstituted tobacco leaf sample; Step 4) The evaluation model for the physical properties of reconstituted tobacco leaf substrate by papermaking method is as follows: ; In the formula, Y is the evaluation value of the physical properties of reconstituted tobacco leaf substrate under the entropy method weighting, and W j X is the weighting coefficient of the j-th physical performance index in the reconstituted tobacco leaf sample. j Let J be the j-th physical property index of the reconstituted tobacco leaf substrate by papermaking, and N be the number of physical properties of the reconstituted tobacco leaf substrate by papermaking.

[0015] More preferably, step (5) uses a papermaking reconstituted tobacco leaf substrate physical property evaluation model to evaluate the physical properties of the papermaking reconstituted tobacco leaf substrate to be evaluated. The specific method is as follows: 1) The physical properties of the papermaking reconstituted tobacco leaf base to be evaluated were determined respectively. The physical property indicators include basis weight X1, thickness X2, tensile strength X3, softness, air permeability X5 and absorbency X6; the reciprocal of softness is recorded as X4. 2) Based on the evaluation model of physical properties of reconstituted tobacco leaf substrate by papermaking method, calculate the evaluation value Y of physical properties of reconstituted tobacco leaf substrate by papermaking method under the entropy value method weight. The larger the value of Y, the better the physical properties of reconstituted tobacco leaf substrate.

[0016] The beneficial effects of this invention are: (1) This invention establishes a multi-dimensional comprehensive evaluation system model for quantitative characterization of the physical properties of reconstituted tobacco leaf substrate, which can more comprehensively and realistically reflect the comprehensive physical properties of reconstituted tobacco leaf substrate; (2) The evaluation model constructed based on the fusion of multiple indicators in this invention realizes quantitative, objective and accurate evaluation, transforming the traditional subjective qualitative evaluation that relies on human senses and experience judgment into a data-driven objective quantitative evaluation, effectively avoiding evaluation bias caused by subjective factors. (3) The reconstituted tobacco leaf physical performance evaluation model of the present invention has excellent predictive and guiding value, realizes forward-looking prediction of the applicability of reconstituted tobacco leaves, reduces the blindness and trial and error costs of R&D, and provides an efficient feedback tool for product formula design and process parameter optimization. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0018] Example 1: A method for evaluating the physical properties of reconstituted tobacco leaf substrate made by papermaking, the specific steps of which are as follows: (1) Test the physical properties of papermaking reconstituted tobacco leaf samples with different raw material ratios (different ratios of stem pulp, leaf pulp, and wood pulp) and different pulping processes (see Table 1); the physical properties include basis weight, thickness, tensile strength, softness, air permeability, and absorbency. (2) Screening of physical performance indicators for reconstituted tobacco leaf substrate samples with preset tensile strength (0.30~0.60kN / m), softness (≤300mN) and absorbency (liquid absorption height ≥25mm) as targets; Table 1 Physical index detection of reconstituted tobacco leaf substrate samples ; (3) The physical performance indicators of the selected reconstituted tobacco leaf samples were normalized (see Table 2), and then Spearman correlation analysis was performed (see Table 4). The specific method for normalization is as follows: The physical performance data of the reconstituted tobacco leaf sample are linearly mapped to the [0,1] interval using a normalization formula; the normalization formula is: ； In the formula: X normalizedThe new data is normalized, and X is the original data. min X is the minimum value of this physical performance index. max This is the maximum value of the physical performance index; Table 2 Normalized physical properties of reconstituted tobacco leaf samples ; The specific method for Spearman correlation analysis is as follows: The normalized reconstituted tobacco leaf sample data of each physical performance index were converted into grades and sorted. The grade difference d and the square of the grade difference d for each physical performance index were calculated. 2 Calculate the Spearman rank correlation coefficient; the formula for calculating the Spearman rank correlation coefficient is: ; In the formula, ρ is the Spearman rank correlation coefficient, which ranges from [-1, 1], and n is the number of samples; Table 3 Spearman Correlation Analysis ; As shown in Table 3, the correlations between basis weight and thickness, and the reciprocal of softness are significant. Specifically, the correlation coefficient between basis weight and thickness is 0.808, showing significance at the 0.05 level, and the correlation coefficient between basis weight and the reciprocal of softness is -0.731, also showing significance at the 0.05 level. Furthermore, the correlations between basis weight and tensile strength, air permeability, and absorbency are not significant (p>0.05), meaning there is no correlation between basis weight and tensile strength, air permeability, and absorbency. (4) Entropy weight analysis was performed on the physical performance indicators of the screened reconstituted tobacco leaf substrate samples (see Table 4) to establish a physical performance evaluation model for papermaking reconstituted tobacco leaf substrate; the specific method is as follows: 1) Calculate the proportion of the i-th reconstituted tobacco leaf sample to the j-th physical performance index in the reconstituted tobacco leaf sample. The calculation formula is as follows: ; In the formula, P ij X represents the proportion of the j-th physical performance index of the i-th reconstituted tobacco leaf substrate sample to that physical performance index. ij Let be the j-th physical performance index in the i-th reconstituted tobacco leaf sample, and n be the number of reconstituted tobacco leaf samples. 2) Calculate the information entropy value of the j-th physical performance index in the reconstituted tobacco leaf sample. The calculation formula is as follows: ; In the formula, e j To determine the information entropy value of the j-th physical performance index in the reconstructed tobacco leaf sample, P ij The weight of the i-th reconstituted tobacco leaf sample relative to the j-th physical performance index in the reconstituted tobacco leaf sample is denoted by n, where n is the number of reconstituted tobacco leaf samples. 3) Calculate the information utility value d of the j-th physical performance index in the reconstituted tobacco leaf sample. j The calculation formula is: d j =1-e j ; In the formula, d j e represents the information utility value of the j-th physical performance index in the reconstituted tobacco leaf sample. j The information entropy value of the j-th physical performance index in the reconstituted tobacco leaf sample; Calculate the weighting coefficient of the j-th physical performance index in the reconstituted tobacco leaf sample, using the following formula: ; In the formula, W j d represents the weighting coefficient of the j-th physical performance index in the reconstituted tobacco leaf sample. j The information utility value of the j-th physical performance index in the reconstituted tobacco leaf sample; Table 4 Entropy Value Method Weight Analysis ; As shown in Table 4, the weight values ​​of basis weight, thickness, tensile strength, reciprocal of softness, air permeability, and absorbency are 14.99%, 11.17%, 9.07%, 31.75%, 21.07%, and 11.96%, respectively. There are certain differences in the weight among the items, with the reciprocal of softness having the highest weight at 31.75% and the lowest weight for basis weight at 9.07%. 4) Establish a physical performance evaluation model for reconstituted tobacco leaf substrate produced by papermaking: ; In the formula, Y is the evaluation value of the physical properties of reconstituted tobacco leaf substrate under the entropy method weighting, and W j X is the weighting coefficient of the j-th physical performance index in the reconstituted tobacco leaf sample. j Let N be the j-th physical property index of the reconstituted tobacco leaf substrate produced by the papermaking method, and N be the number of physical properties of the reconstituted tobacco leaf substrate produced by the papermaking method; specifically, the evaluation model is as follows: Y=14.99%*X1+11.16%*X2+9.07%*X3+31.75%*X4+21.07%*X5+11.96%*X6 In the formula, Y is the physical performance evaluation value of reconstituted tobacco leaf substrate under the entropy method weight, X1 is basis weight, X2 is thickness, X3 is tensile strength, X4 is the reciprocal of softness, X5 is air permeability, and X6 is absorbency. (5) The physical properties of the reconstituted tobacco leaf substrate by papermaking method are evaluated using the evaluation model. The specific method is as follows: 1) The physical properties of the papermaking reconstituted tobacco leaf base to be evaluated were determined (see Table 5). The physical property indicators include basis weight X1, thickness X2, tensile strength X3, softness, air permeability X5 and absorbency X6; the reciprocal of softness is recorded as X4. 2) Based on the evaluation model of physical properties of reconstituted tobacco leaves by papermaking method, the evaluation value Y of physical properties of reconstituted tobacco leaves by papermaking method under the entropy method weight is calculated (see Table 5). The larger the Y value, the better the physical properties of reconstituted tobacco leaves. Table 5 Evaluation of Physical Properties of Reconstituted Tobacco Leaf Substrate ; As shown in Table 5, the evaluation results of the series of reconstituted tobacco leaf substrates by the physical performance evaluation model of reconstituted tobacco leaf substrates show that RT-3 has the best performance, followed by C-1, C-2, C-3, D-1, X-2, R-2, and RT-2, while the performance of the others is average.

[0019] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method of evaluating the physical properties of paper process reconstituted tobacco sheet, characterized by, The specific steps are as follows: (1) detecting the physical performance indexes of the papermaking process reconstituted tobacco sheet base samples with different raw material ratios and different pulping processes; the physical performance indexes include basis weight, thickness, tensile strength, softness, air permeability and absorbency; (2) performing physical performance index screening on the reconstituted tobacco sheet base samples with preset tensile strength, softness and absorbency as the targets; (3) performing normalization processing on the screened physical performance indexes of the reconstituted tobacco sheet base samples, and then performing Spearman correlation analysis; (4) performing entropy method weight analysis on the screened physical performance indexes of the reconstituted tobacco sheet base samples, and establishing a papermaking process reconstituted tobacco sheet base physical performance evaluation model; (5) using the papermaking process reconstituted tobacco sheet base physical performance evaluation model to evaluate the physical performance of the papermaking process reconstituted tobacco sheet base to be evaluated.

2. The method of evaluating the physical properties of paper process reconstituted tobacco sheet according to claim 1, characterized in that: In step (1), the different raw material ratios are different ratios of stem pulp, leaf pulp and wood pulp.

3. The method of evaluating the physical properties of paper process reconstituted tobacco sheet according to claim 1, characterized in that: In step (2), the preset tensile strength is 0.30-0.60 kN / m, the softness is ≤300 mN, and the liquid absorption height of the absorbency is ≥25 mm.

4. The method of evaluating the physical properties of paper process reconstituted tobacco sheet according to claim 1, characterized in that: In step (3), the specific method of normalization processing is to linearly map the physical performance index data of the reconstituted tobacco sheet base samples to the [0, 1] interval by using a normalization formula; the normalization formula is: ； where: X normalized is the normalized new data, X is the original data, X min is the minimum value of the physical performance indicator. X max is the maximum value of the physical performance indicator.

5. The method of evaluating the physical properties of paper process reconstituted tobacco sheet according to claim 1, characterized in that: The specific method of Spearman correlation analysis in step (3) is: The physical performance index data of the normalized reconstituted tobacco sheet base sample are converted into grades and sorted, and the grade difference d of each physical performance index data and the square of the grade difference d are calculated 2 , and the Spearman rank correlation coefficient is calculated.

6. The method of evaluating the physical properties of paper process reconstituted tobacco sheet according to claim 5, characterized in that: The calculation formula of the Spearman rank correlation coefficient is: ； In the formula, ρ is the Spearman rank correlation coefficient, the value range is [-1, 1], and n is the number of samples.

7. The method of evaluating the physical properties of paper process reconstituted tobacco sheet according to claim 1, characterized in that: In step (4), the entropy method weight analysis is performed on the screened physical performance indexes of the reconstituted tobacco sheet base samples, and a papermaking process reconstituted tobacco sheet base physical performance evaluation model is established, and the specific method is: 1) calculating the proportion of the i th reconstituted tobacco sheet base sample in the j th physical performance index of the reconstituted tobacco sheet base sample; 2) calculating the information entropy value of the j th physical performance index of the reconstituted tobacco sheet base sample; 3) calculating the information utility value d of the jth physical performance index in the reconstituted tobacco leaf base sample respectively j and the weight coefficient of the jth physical performance index in the reconstituted tobacco leaf base sample; 4) establishing a papermaking process reconstituted tobacco sheet base physical performance evaluation model.

8. The method of evaluating the physical properties of paper process reconstituted tobacco sheet according to claim 7, characterized in that: In step 1), the proportion of the i th reconstituted tobacco sheet base sample in the j th physical performance index of the reconstituted tobacco sheet base sample is calculated by the formula: ； In the formula, P ij is the proportion of the i th reconstituted tobacco sheet base sample in the j th physical performance index of the reconstituted tobacco sheet base sample, X ij is the j th physical performance index of the i th reconstituted tobacco sheet base sample, and n is the number of reconstituted tobacco sheet base samples. In step 2), the information entropy value of the j th physical performance index of the reconstituted tobacco sheet base sample is calculated by the formula: ； In the formula, e j is the information entropy value of the jth physical performance index in the reconstituted tobacco base sample, P ij is the proportion of the ith reconstituted tobacco base sample in the jth physical performance index in the reconstituted tobacco base sample, and n is the number of reconstituted tobacco base samples. Step 3) calculating the information utility value d of the jth physical performance index in the reconstituted tobacco leaf sheet sample j The calculation formula is: d j =1-e j ; In the formula, d j is the information utility value of the jth physical performance index in the reconstituted tobacco sheet base sample, e j is the information entropy value of the jth physical performance index in the reconstituted tobacco sheet base sample. In step 3), the weight coefficient of the j th physical performance index of the reconstituted tobacco sheet base sample is calculated by the formula: ； In the formula, W j is the weight coefficient of the jth physical performance index in the reconstituted tobacco leaf base sample, d j is the information utility value of the jth physical performance index in the reconstituted tobacco leaf base sample. In step 4), the papermaking process reconstituted tobacco sheet base physical performance evaluation model is: ; In the formula, Y is the evaluation value of the physical properties of the papermaking process reconstituted tobacco sheet substrate under the entropy value method weight, W j is the weight coefficient of the jth physical property index in the reconstituted tobacco sheet substrate, X j is the jth physical property index of the papermaking process reconstituted tobacco sheet substrate, and N is the number of the physical property indexes of the papermaking process reconstituted tobacco sheet substrate.

9. The method of evaluating the physical properties of paper process reconstituted tobacco sheet according to claim 8, characterized in that: In step (5), the specific method of using the papermaking process reconstituted tobacco sheet base physical performance evaluation model to evaluate the physical performance of the papermaking process reconstituted tobacco sheet base to be evaluated is: 1) respectively measuring the physical performance of the papermaking process reconstituted tobacco sheet base to be evaluated, the physical performance indexes include basis weight X1, thickness X2, tensile strength X3, softness, air permeability X5 and absorbency X6; the reciprocal of the softness is recorded as X4; 2) According to the evaluation model of the physical properties of the paper-process reconstituted tobacco sheet, the physical property evaluation value Y of the paper-process reconstituted tobacco sheet under the entropy weight is calculated. The greater the Y value, the better the physical properties of the reconstituted tobacco sheet.

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