A method of filter rod production

Abstract

This invention discloses a filter rod production method, comprising the following steps: obtaining a predictive model characterizing the relationship between filter rod hardness and absorbance resistance, glycerol content, and curing time; obtaining an absorbance resistance adjustment condition model and a glycerol content adjustment condition model based on the predictive model; obtaining the measured absorbance resistance value and measured glycerol content value of the produced filter rod, and obtaining the predicted hardness value of the filter rod based on the measured absorbance resistance value, measured glycerol content value, and predictive model; when the predicted hardness value does not match the preset range of filter rod hardness, obtaining a first hardness adjustment value based on the measured absorbance resistance value and absorbance resistance adjustment condition model; obtaining a second hardness adjustment value based on the measured glycerol content value and glycerol content adjustment condition model; adjusting the glycerol content parameter and / or absorbance resistance parameter of the filter rod production line based on the predicted hardness value, the first hardness adjustment value, and the second hardness adjustment value. This invention enables precise control of filter rod hardness during production, reduces fluctuations in filter rod hardness values, and greatly improves product stability.

Description

Technical Field

[0001] This invention relates to the field of filter rods, and in particular to a method for producing filter rods. Background Technology

[0002] As the filter tip of cigarettes, the filter rod must possess a certain degree of hardness before being used in the rolling process. Otherwise, defects such as wrinkling and air leakage will occur during the rolling process, affecting the consumer experience. Therefore, a plasticizer (usually triacetin, or glycerol for short) needs to be added during the production of the filter rod to accelerate its shaping and achieve a certain degree of hardness. However, since the plasticizer is initially liquid, it needs to be stored for at least 6 hours after production to solidify and increase the filter rod's hardness. According to production process requirements and testing, the solidification time is generally 6 hours. Too short a time does not meet process requirements, while too long a time increases inventory costs. Furthermore, research shows that after a solidification time greater than 24 hours, the hardness no longer changes. If the filter tip hardness cannot be effectively adjusted within the solidification time, there will be large fluctuations in the filter rod's hardness value, resulting in insufficient product stability.

[0003] Currently, the main method for adjusting hardness is to let the filter rods stand for 6 hours after production before testing their hardness, and then adjust the hardness based on the test results by increasing or decreasing the amount of plasticizer added. However, because this method is simplistic and lacks specific guidelines, frequent adjustments are necessary, and instances of unacceptable hardness after adjustments frequently occur. This leads to significant fluctuations in the hardness of the filter rods, severely affecting their stability and resulting in a low pass rate. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of large fluctuations in filter rod hardness values, low hardness qualification rates, and insufficient product stability. This invention provides a filter rod manufacturing method that allows for precise control of filter rod hardness during production, reducing fluctuations in hardness values ​​and significantly improving product stability.

[0005] To address the aforementioned technical problems, embodiments of the present invention disclose a method for producing filter rods, comprising the following steps:

[0006] Obtain a predictive model characterizing the relationship between filter rod hardness and suction resistance, glycerol content, and curing time;

[0007] Based on the prediction model, the absorption resistance adjustment condition model and the glycerol content adjustment condition model were obtained;

[0008] Obtain the measured absorption resistance value and measured glycerol content value of the produced filter rod, and obtain the predicted hardness value of the filter rod based on the measured absorption resistance value, measured glycerol content value and prediction model;

[0009] When the predicted hardness value does not match the preset range of filter rod hardness, the first hardness adjustment value is obtained based on the measured suction resistance value and the suction resistance adjustment condition model; the second hardness adjustment value is obtained based on the measured glycerol content value and the glycerol content adjustment condition model.

[0010] Adjust the glycerol content parameters and / or suction resistance parameters of the filter rod production line based on the predicted hardness value, the first hardness adjustment value, and the second hardness adjustment value.

[0011] By adopting the above technical solution, the hardness of the filter rod after a certain curing time can be predicted by a predictive model during the production of the filter rod. This provides a basis for controlling the hardness of the filter rod during the production process. Based on the predicted hardness of the filter rod, the first hardness adjustment value A related to suction resistance, and the hardness adjustment value B related to glycerol content, the suction resistance parameters or glycerol content parameters during the production process can be adjusted to keep the hardness of the filter rod within a preset range. The adjustment accuracy is high, which can ensure the stability of the hardness of the filter rod, reduce the fluctuation of the hardness of the filter rod, and improve the pass rate of the filter rod.

[0012] As one specific implementation, the glycerol content parameters and / or suction resistance parameters of the filter rod production line are adjusted based on the predicted hardness value, the first hardness adjustment value, and the second hardness adjustment value, including:

[0013] When the predicted hardness value is greater than the upper limit of the preset range of filter rod hardness, and at least one of the first hardness adjustment value and the second hardness adjustment value is positive, it is determined whether the first hardness adjustment value is greater than the second hardness adjustment value. If so, the suction resistance parameter is adjusted according to the first hardness adjustment value; otherwise, the glycerol content parameter is adjusted according to the second hardness adjustment value.

[0014] When the predicted hardness value is less than the lower limit of the preset range of filter rod hardness, and at least one of the first hardness adjustment value and the second hardness adjustment value is negative, it is determined whether the first hardness adjustment value is less than the second hardness adjustment value. If so, the suction resistance parameter is adjusted according to the first hardness adjustment value; otherwise, the glycerol content parameter is adjusted according to the second hardness adjustment value.

[0015] As one specific implementation method, it also includes:

[0016] When the predicted hardness value is greater than the upper limit of the preset range of filter rod hardness, and both the first hardness adjustment value and the second hardness adjustment value are positive, if the predicted hardness value is still greater than the upper limit of the preset range of filter rod hardness after adjusting the suction resistance parameter, adjust the glycerol content parameter; or if the predicted hardness value is still greater than the upper limit of the preset range of filter rod hardness after adjusting the glycerol content parameter, adjust the suction resistance parameter.

[0017] When the predicted hardness value is less than the lower limit of the preset range of filter rod hardness, and both the first hardness adjustment value and the second hardness adjustment value are negative or positive, if the predicted hardness value is still less than the lower limit of the preset range of filter rod hardness after adjusting the suction resistance parameter, adjust the glycerol content parameter; or if the predicted hardness value is still greater than the upper limit of the preset range of filter rod hardness after adjusting the glycerol content parameter, adjust the suction resistance parameter.

[0018] As one specific implementation method, it also includes:

[0019] When the predicted hardness value is greater than the upper limit of the preset range of filter rod hardness, if both the first hardness adjustment value and the second hardness adjustment value are negative, no adjustment will be made and an alarm will be issued.

[0020] When the predicted hardness value is less than the lower limit of the preset range of filter rod hardness, if both the first hardness adjustment value and the second hardness adjustment value are positive, no adjustment will be made and an alarm will be issued.

[0021] As a specific implementation, it also includes: when the predicted hardness value is within the preset range of filter rod hardness, no adjustment is required.

[0022] As a specific implementation method, a predictive model characterizing the relationship between filter rod hardness and suction resistance, glycerol content, and curing time is obtained, including:

[0023] The hardness values ​​of filter rods prepared under different process parameters were obtained, including suction resistance, glycerol content and curing time.

[0024] Based on the hardness values ​​of each sample filter rod and the corresponding process parameters, a predictive model characterizing the relationship between filter rod hardness and each process parameter is constructed.

[0025] As a specific implementation method, the hardness values ​​of filter rods prepared under different process parameters are obtained, including:

[0026] Acquire the absorbance, glycerol content, and hardness values ​​of sample filter rods produced under multiple different glycerol contents and multiple different curing times when the absorbance is adjusted to the first absorbance, and form a first data set;

[0027] Acquire the absorbance, glycerol content, and hardness values ​​of sample filter rods produced under multiple different glycerol contents and multiple different curing times when the absorbance is adjusted to the second absorbance, and form a second data set;

[0028] When the suction resistance is adjusted to the third suction resistance, the suction resistance, the glycerol content, and the hardness of the sample filter rods produced under multiple different glycerol contents and multiple different curing times are obtained to form a third data set.

[0029] A prediction model is constructed based on the first, second, and third data sets.

[0030] As a specific implementation method, the prediction model is as follows:

[0031] SD=65.699+0.006010R+0.5007G+0.33743M

[0032] Where SD is the hardness value, R is the suction resistance value, G is the glycerin content, and M is the curing time.

[0033] As a specific implementation method, the suction resistance adjustment condition model is as follows:

[0034] A = 0.0601 * (aX) / 10

[0035] Where A is the first hardness adjustment value, a is the measured suction resistance value, and X is the suction resistance threshold.

[0036] As a specific implementation method, the glycerol content adjustment condition model is as follows:

[0037] B = 0.05007 * (bY)

[0038] Where B is the second hardness adjustment value, b is the measured glycerol content value, and Y is the glycerol content threshold. Attached Figure Description

[0039] Figure 1 A flowchart illustrating the filter rod production method according to an embodiment of the present invention is shown;

[0040] Figure 2 The box plot shows the difference between the measured hardness after the priority adjustment index is adjusted and the predicted hardness value after the priority adjustment index is adjusted.

[0041] Figure 3 The box plot shows the difference between the measured hardness value after adjustment by the second adjustment index and the predicted hardness value after adjustment by the second adjustment index. Detailed Implementation

[0042] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a deep understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0043] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0044] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0045] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below.

[0046] This invention discloses a method for producing filter rods, referring to... Figure 1 This includes the following steps:

[0047] Step S1: Obtain a predictive model characterizing the relationship between filter rod hardness and suction resistance, glycerol content, and curing time. There are multiple production parameters in filter rod manufacturing, including not only suction resistance, glycerol content, and curing time, but also indicators such as filter rod weight, circumference, and length. When constructing the predictive model, these relevant process parameters are analyzed, and parameters unrelated to hardness or unable to be controlled independently are eliminated. Finally, a model is constructed to represent the relationship between suction resistance, glycerol content, and curing time. Further, the predictive model is as follows:

[0048] SD=65.699+0.006010R+0.5007G+0.33743M

[0049] Where SD is the hardness value, R is the suction resistance value, G is the glycerin content, and M is the curing time.

[0050] Step S2: Obtain the absorption resistance adjustment condition model and the glycerol content adjustment condition model based on the prediction model. Specifically, as shown in the prediction model above, when the curing time is constant, such as setting the curing time to 6 hours, the hardness mainly changes with the changes in absorption resistance and glycerol content. The absorption resistance adjustment condition model is constructed by adjusting the change in hardness when adjusting the minimum unit absorption resistance value, and the glycerol content adjustment condition model is constructed by adjusting the change in hardness when adjusting the minimum unit glycerol content.

[0051] For example, if the minimum adjustment unit for suction resistance is 10 (Pa), then, based on the above prediction model, when the suction resistance is adjusted by 10 (Pa), the hardness changes by 0.0601 (%). Therefore, the suction resistance adjustment condition model is as follows:

[0052] A = 0.0601 * (aX) / 10

[0053] Where A is the first hardness adjustment value, a is the measured suction resistance value, and X is the suction resistance threshold. A positive first hardness adjustment value A indicates that the suction resistance is too high and should be reduced; a negative value A indicates that the suction resistance is too low and should be increased.

[0054] Furthermore, the minimum adjustment unit for glycerol content is 0.1 (%). Based on the above prediction model, when the glycerol content is adjusted by 0.1 (%), the hardness changes by 0.05007 (%). Therefore, the glycerol content adjustment condition model is as follows:

[0055] B = 0.05007 * (bY)

[0056] Where B is the second hardness adjustment value, b is the measured glycerol content value, and Y is the glycerol content threshold. A positive second hardness adjustment value B indicates that the glycerol content is too high and should be reduced, while a negative B value indicates that the glycerol content is too low and should be increased.

[0057] Step S3: Obtain the measured absorbance and glycerol content values ​​of the filter rod during production, and obtain the predicted hardness value of the filter rod based on the measured absorbance, glycerol content, and prediction model. In other words, the absorbance and glycerol content values ​​are monitored in real time during production. The prediction model from step S1 is used to predict the hardness of the filter rod after a set curing time. That is, the hardness of the cured filter rod can be predicted during production using hardness-related absorbance and glycerol content indicators. If the predicted hardness of the cured filter rod does not meet the requirements, the filter rod in production can be adjusted in a timely manner, providing a basis for controlling the hardness of the filter rod.

[0058] Step S4: When the predicted hardness value does not match the preset range of filter rod hardness, the first hardness adjustment value is obtained based on the measured suction resistance value and the suction resistance adjustment condition model; the second hardness adjustment value is obtained based on the measured glycerol content value and the glycerol content adjustment condition model.

[0059] The hardness of the cured filter rod needs to meet certain requirements, specifically, the hardness value needs to be within a preset range. The predicted hardness obtained in step S3 is compared with the preset range. If the predicted hardness value is not within the preset range, it indicates that the hardness of the filter rod produced with the current production parameters does not meet the requirements after curing, and the production parameters need to be adjusted. In this embodiment, when the predicted hardness value does not meet the requirements, the hardness of the filter rod is adjusted by adjusting the absorption resistance or glycerol content during the production process.

[0060] During production, the absorbance and glycerol content of the filter rod also need to meet set conditions. In the absorbance adjustment condition model, X is the absorbance threshold; in the glycerol content adjustment condition model, Y is the glycerol content threshold. X and Y determine the control range of absorbance and glycerol content during production. Therefore, by using the difference between the measured absorbance value and the absorbance threshold, and the absorbance adjustment condition model, the hardness value that can be adjusted by the absorbance is obtained. Similarly, by using the difference between the measured glycerol content value and the glycerol content threshold, and the glycerol content adjustment condition model, the hardness value that can be adjusted by the glycerol content is obtained.

[0061] Step S5: Adjust the glycerol content parameters and / or suction resistance parameters of the filter rod production line based on the predicted hardness value, the first hardness adjustment value, and the second hardness adjustment value. Specifically, this includes the following steps:

[0062] When the predicted hardness value is greater than the upper limit of the preset range for filter rod hardness, and at least one of the first hardness adjustment value A and the second hardness adjustment value B is positive, it is determined whether the first hardness adjustment value A is greater than the second hardness adjustment value B. If so, the suction resistance parameter is adjusted according to the first hardness adjustment value A; otherwise, the glycerol content parameter is adjusted according to the second hardness adjustment value B. This situation includes two cases: both the first hardness adjustment value A and the second hardness adjustment value B are positive, and one is positive and the other is negative.

[0063] Furthermore, when the predicted hardness value exceeds the upper limit of the preset hardness range for the filter rod, if one of the first hardness adjustment value A and the other of the second hardness adjustment value B is positive and the other is negative, only the indicator with the larger value between the two values ​​is adjusted; that is, only the indicator with a positive value between the two values ​​is adjusted. If both the first hardness adjustment value A and the second hardness adjustment value B are positive, then the parameter with the larger value between the two values ​​is adjusted first, and this parameter is the priority adjustment indicator. If the predicted hardness value still does not meet the preset range requirements after adjusting the priority adjustment indicator, then another parameter is adjusted; this other indicator is the second adjustment indicator.

[0064] For example, if both the first hardness adjustment value A and the second hardness adjustment value B are positive, and the first hardness adjustment value A is greater than the second hardness adjustment value B, the suction resistance is adjusted first. If, after adjusting the suction resistance parameter, the predicted hardness value of the filter rod is still greater than the upper limit of the preset range of filter rod hardness, then the second adjustment index, glycerol content, is adjusted. If the first hardness adjustment value A is less than the second hardness adjustment value B, the glycerol content parameter is adjusted first. If, after adjusting the glycerol content parameter, the predicted hardness value is still greater than the upper limit of the preset range of filter rod hardness, then the second adjustment index, suction resistance parameter, is adjusted.

[0065] When the predicted hardness value is less than the lower limit of the preset range for filter rod hardness, and at least one of the first hardness adjustment value A and the second hardness adjustment value B is negative, it is determined whether the first hardness adjustment value A is less than the second hardness adjustment value B. If so, the suction resistance parameter is adjusted according to the first hardness adjustment value A; otherwise, the glycerol content parameter is adjusted according to the second hardness adjustment value B. This situation includes two cases: both the first hardness adjustment value A and the second hardness adjustment value B are negative, and one is negative while the other is positive.

[0066] Furthermore, when the predicted hardness value is less than the lower limit of the preset hardness range of the filter rod, if one of the first hardness adjustment value A and the other of the second hardness adjustment value B is positive and negative, then only the parameter with the negative value is adjusted. If both the first hardness adjustment value A and the second hardness adjustment value B are negative, the parameter with the smaller value (i.e., the parameter with the larger absolute value) is adjusted first; this parameter is the priority adjustment index. If the predicted hardness value of the filter rod still does not meet the requirements of the preset hardness range after adjusting the priority adjustment index, then another parameter is adjusted; this second parameter is the second adjustment index.

[0067] For example, if both the first hardness adjustment value A and the second hardness adjustment value B are negative, and the first hardness adjustment value A is less than the second hardness adjustment value B (i.e., the absolute value of the first hardness adjustment value A is greater than the second hardness adjustment value B), the suction resistance parameter is adjusted first. If, after adjusting the suction resistance parameter, the predicted hardness value of the filter rod is still less than the lower limit of the preset range of filter rod hardness, then the second adjustment index, the glycerol content parameter, is adjusted. Similarly, if the first hardness adjustment value A is greater than the second hardness adjustment value B (i.e., the absolute value of the first hardness adjustment value A is less than the second hardness adjustment value B), the glycerol content parameter is adjusted first. If, after adjusting the glycerol content parameter, the predicted hardness value of the filter rod is still greater than the lower limit of the preset range of filter rod hardness, then the second adjustment index, the suction resistance parameter, is adjusted.

[0068] Step S5 further includes: when the predicted hardness value is greater than the upper limit of the preset range of filter rod hardness, if both the first hardness adjustment value A and the second hardness adjustment value B are negative, no adjustment is made and an alarm is issued. When the predicted hardness value is less than the lower limit of the preset range of filter rod hardness, if both the first hardness adjustment value A and the second hardness adjustment value B are positive, no adjustment is made and an alarm is issued.

[0069] Step S5 also includes: when the predicted hardness value is within the preset range of filter rod hardness, no adjustment is required.

[0070] Specifically, step S1 involves obtaining a predictive model characterizing the relationship between filter rod hardness and suction resistance, glycerol content, and curing time, including:

[0071] Step S11: Obtain the hardness values ​​of each sample filter rod prepared under different process parameters, including suction resistance, glycerol content and curing time;

[0072] Step S12: Based on the hardness values ​​of each sample filter rod obtained in step S11 and the corresponding process parameters, construct a predictive model characterizing the relationship between the filter rod hardness and each process parameter.

[0073] Furthermore, the hardness values ​​of the filter rods prepared under different process parameters were obtained, including:

[0074] Acquire the absorbance, glycerol content, and hardness values ​​of sample filter rods produced under multiple different glycerol contents and multiple different curing times when the absorbance is adjusted to the first absorbance, and form a first data set;

[0075] Acquire the absorbance, glycerol content, and hardness values ​​of sample filter rods produced under multiple different glycerol contents and multiple different curing times when the absorbance is adjusted to the second absorbance, and form a second data set;

[0076] When the suction resistance is adjusted to the third suction resistance, the suction resistance, the glycerol content, and the hardness of the sample filter rods produced under multiple different glycerol contents and multiple different curing times are obtained to form a third data set.

[0077] A prediction model is constructed based on the first, second, and third data sets.

[0078] For example, when obtaining the prediction model that characterizes the relationship between filter rod hardness and suction resistance, glycerol content and curing time, the first suction resistance is set to 2940 Pa-2960 Pa, the second suction resistance is set to 2990 Pa-3010 Pa, the third suction resistance is set to 3040 Pa-3060 Pa, the glycerol content is set to 8.5%, 9%, 9.5% and 10%, and the curing time is set to 2 hours, 4 hours and 6 hours.

[0079] The online hardness prediction method of this embodiment will be described using the above parameters as an example:

[0080] In step S11, obtaining the hardness values ​​of each sample filter rod prepared under different process parameters specifically includes:

[0081] With the equipment running normally, adjust the suction resistance to the first suction resistance, which is 2940 Pa to 2960 Pa. Then adjust the glycerol content to four gradients: 10%, 9.5%, 9%, and 8.5%. Take two sets of samples for each gradient, for a total of eight sets of samples, which are designated as the first to the eighth sample sets. Take 90 samples from each set and divide each set into three parts, and number them accordingly. For example, the three parts of the first sample set are designated as 1-1, 1-2, and 1-3, the three parts of the second sample set are designated as 2-1, 2-2, and 2-3, and so on. Record the sampling time.

[0082] With the equipment operating normally, adjust the suction resistance to the second suction resistance, which is 2990 Pa to 3010 Pa. Then adjust the glycerol content to four gradients: 10%, 9.5%, 9%, and 8.5%. Take two sets of samples for each glycerol content gradient, for a total of eight sets of samples, which are designated as the ninth to sixteenth sample groups. Take 90 samples from each sample group and divide each sample group into three parts, and number them accordingly. For example, the three parts of the ninth sample group are designated as 9-1, 9-2, and 9-3, the three parts of the tenth sample group are designated as 10-1, 10-2, and 10-3, and so on. Record the sampling time.

[0083] With the equipment operating normally, adjust the suction resistance to the third level, which is 3040 Pa to 3060 Pa. Then adjust the glycerol content to four gradients: 10%, 9.5%, 9%, and 8.5%. Take two sets of samples for each gradient, for a total of eight sets of samples, which are designated as the seventeenth to twenty-fourth sample groups. Take 90 samples from each sample group and divide each sample group into three parts, and number them accordingly. For example, the three parts of the seventeenth sample group are designated as 17-1, 17-2, and 17-3, and the three parts of the seventeenth sample group are designated as 18-1, 18-2, and 19-3, and so on. Record the sampling time.

[0084] After sampling a total of 24 filter rod samples, according to the recorded sampling time, at the time points when the sample filter rods had been stored for 2 hours, 4 hours, and 6 hours (and when the set curing time was reached), the various production parameters of filter rod samples numbered 1, 2, and 3 in each sample group were measured, and the average absorbance resistance, average glycerol content, and average hardness of the corresponding filter rod samples were recorded. That is, the curing time for sample number 1 in each sample group was 2 hours, the curing time for sample number 2 in each sample group was 4 hours, and the curing time for sample number 3 in each sample group was 6 hours. This setup allows for keeping any two of the three parameters—absorbance resistance, glycerol content, and curing time—constant, and then measuring the relationship between the remaining parameter and the filter rod hardness. As in the above steps, two sets of filter rod samples with the same three process parameters were set up for each sample to facilitate comparison and ensure data accuracy.

[0085] In step S12, regression analysis can be used to process the data in step S11 to obtain the above prediction model.

[0086] Furthermore, the effectiveness of the filter rod production method according to the embodiments of this application was verified in actual production as follows:

[0087] For example, if the control range of the absorbance parameter is set to 3000±240 Pa, with a center value of 3000 Pa, then the absorbance adjustment condition model is: A=0.0601*(a-3000) / 10. If the control range of the glycerol content parameter is set to 9±1%, with a center value of 9%, then the glycerol content adjustment condition model is: B=0.05007*(b-9) / 0.1.

[0088] Taking a filter rod hardness preset range of 90±3% as an example, with a center value of 90%, the preset hardness range is 87%-93%. In actual operation, to make the preset hardness value closer to the center value, an additional deviation range of 1% can be added, that is, the preset hardness range of the filter rod is 89%-91%.

[0089] By setting the above parameters, the actual hardness of the filter rod is obtained during production without adjustment. The actual hardness of the filter rod after adjustment based on the priority adjustment index and the actual hardness after adjustment based on the secondary index are also obtained using the method of this embodiment. The corresponding absorbence resistance and glycerol content values ​​detected in real time during production are recorded. The first hardness adjustment value A and the second hardness adjustment value B are obtained based on the absorbence resistance adjustment condition model and the glycerol content adjustment condition model. The predicted hardness values ​​after adjustment based on the priority adjustment index and the second adjustment index are also recorded. Specific data are as follows:

[0090] Table 1: Data on suction resistance, glycerol content, original hardness value, predicted hardness value of the filter rod, and measured hardness value of the adjusted filter rod.

[0091]

[0092]

[0093] As can be seen from the above verification data, the production method of this embodiment can reduce the original measured hardness fluctuation SD of 0.81 to 0.48.

[0094] The consistency and difference between the adjusted measured hardness value and the predicted hardness value were further analyzed using a paired t-test. The paired test was verified as follows:

[0095] Paired T-test of measured hardness (%) after priority adjustment index adjustment, predicted hardness (%) after priority adjustment index adjustment, and measured hardness (%) - predicted hardness (%) after priority adjustment index adjustment:

[0096]

[0097] Based on the above, the 95% confidence interval for the mean difference is (-0.0443, 0.0283).

[0098] T-test for mean difference = 0 (and ≠ 0): T-value = -0.46, P-value = 0.650. Box plot of the difference is shown below. Figure 2 As shown.

[0099] Paired T-test of measured hardness value (%) adjusted for the second adjustment index, predicted hardness value (%) adjusted for the second adjustment index, and measured hardness value (%) adjusted for the second adjustment index minus predicted hardness value (%) adjusted for the second adjustment index:

[0100]

[0101] Based on the above, the 95% confidence interval for the mean difference is (-0.0541, 0.0131).

[0102] T-test for mean difference = 0 (and ≠ 0): T-value = -1.28, P-value = 0.217. Box plot of the difference is shown below. Figure 3 As shown.

[0103] As can be seen from the above analysis, the P values ​​are all >0.05, and there is no significant difference between the adjusted measured hardness and the predicted hardness. The production method implemented in this paper can be used to adjust the hardness of the filter rod in the actual production process.

[0104] After the production method of this embodiment is applied to actual production, the accuracy of filter rod hardness adjustment is greatly improved and the hardness fluctuation is greatly reduced. The following is a comparison of the accuracy of filter rod hardness adjustment, filter rod hardness qualification rate, and filter rod fluctuation before and after the application of this embodiment:

[0105] category Before application After application Adjust accuracy 5-10 adjustments 1-2 adjustments Hardness pass rate 91％ 99.9％ Hardness SD 0.81 0.48

[0106] In summary, the technical solution of this application embodiment can predict the hardness of the filter rod after a certain curing time during filter rod production, providing a basis for controlling the hardness of the filter rod during the production process. Based on the predicted filter rod hardness, the first hardness adjustment value A related to suction resistance, and the hardness adjustment value B related to glycerol content, the suction resistance and glycerol content during the production process are adjusted to keep the filter rod hardness within a preset range. The adjustment accuracy is high, which achieves the effect of ensuring the stability of the filter rod hardness, reducing the fluctuation of the filter rod hardness, and improving the pass rate of the filter rod.

[0107] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A method for producing filter rods, characterized in that, Includes the following steps: Obtain a predictive model characterizing the relationship between filter rod hardness and suction resistance, glycerol content, and curing time; Based on the prediction model, obtain the absorption resistance adjustment condition model and the glycerol content adjustment condition model; Obtain the measured absorbance value and measured glycerol content value of the produced filter rod, and obtain the predicted hardness value of the filter rod based on the measured absorbance value, the measured glycerol content value and the prediction model; When the predicted hardness value does not match the preset range of filter rod hardness, a first hardness adjustment value is obtained based on the measured suction resistance value and the suction resistance adjustment condition model; a second hardness adjustment value is obtained based on the measured glycerol content value and the glycerol content adjustment condition model. Adjusting the glycerol content parameters and / or suction resistance parameters of the filter rod production line based on the predicted hardness value, the first hardness adjustment value, and the second hardness adjustment value includes: When the predicted hardness value is greater than the upper limit of the preset range of filter rod hardness, and at least one of the first hardness adjustment value and the second hardness adjustment value is positive, it is determined whether the first hardness adjustment value is greater than the second hardness adjustment value. If so, the suction resistance parameter is adjusted according to the first hardness adjustment value; otherwise, the glycerol content parameter is adjusted according to the second hardness adjustment value. When the predicted hardness value is less than the lower limit of the preset range of filter rod hardness, and at least one of the first hardness adjustment value and the second hardness adjustment value is negative, it is determined whether the first hardness adjustment value is less than the second hardness adjustment value. If so, the suction resistance parameter is adjusted according to the first hardness adjustment value; otherwise, the glycerol content parameter is adjusted according to the second hardness adjustment value.

2. The filter rod production method as described in claim 1, characterized in that, Also includes: When the predicted hardness value is greater than the upper limit of the preset range of filter rod hardness, and both the first hardness adjustment value and the second hardness adjustment value are positive, if the predicted hardness value is still greater than the upper limit of the preset range of filter rod hardness after adjusting the suction resistance parameter, the glycerol content parameter is adjusted; or if the predicted hardness value is still greater than the upper limit of the preset range of filter rod hardness after adjusting the glycerol content parameter, the suction resistance parameter is adjusted. When the predicted hardness value is less than the lower limit of the preset range of filter rod hardness, and both the first hardness adjustment value and the second hardness adjustment value are negative or positive, if the predicted hardness value is still less than the lower limit of the preset range of filter rod hardness after adjusting the suction resistance parameter, the glycerol content parameter is adjusted; or if the predicted hardness value is still greater than the upper limit of the preset range of filter rod hardness after adjusting the glycerol content parameter, the suction resistance parameter is adjusted.

3. The filter rod production method as described in claim 1, characterized in that, Also includes: When the predicted hardness value is greater than the upper limit of the preset range of the filter rod hardness, if both the first hardness adjustment value and the second hardness adjustment value are negative, no adjustment will be made and an alarm will be issued. When the predicted hardness value is less than the lower limit of the preset range of filter rod hardness, if both the first hardness adjustment value and the second hardness adjustment value are positive, no adjustment will be made and an alarm will be issued.

4. The filter rod production method as described in claim 1, characterized in that, Also includes: When the predicted hardness value is within the preset range of the filter rod hardness, no adjustment is required.

5. The method for producing filter rods according to any one of claims 1-4, characterized in that, A predictive model was developed to characterize the relationship between filter rod hardness and suction resistance, glycerol content, and curing time, including: The hardness values ​​of filter rods prepared under different process parameters were obtained, including suction resistance, glycerol content, and curing time. Based on the hardness values ​​of each of the sample filter rods and the corresponding process parameters, a prediction model characterizing the relationship between the filter rod hardness and each of the process parameters is constructed.

6. The filter rod production method as described in claim 5, characterized in that, Obtain the hardness values ​​of filter rods prepared under different process parameters, including: Acquire the absorbance, glycerol content, and hardness values ​​of sample filter rods produced under multiple different glycerol contents and multiple different curing times when the absorbance is adjusted to the first absorbance, and form a first data set; Acquire the absorbance, glycerol content, and hardness values ​​of sample filter rods produced under multiple different glycerol contents and multiple different curing times when the absorbance is adjusted to the second absorbance, and form a second data set; When the suction resistance is adjusted to the third suction resistance, the suction resistance, the glycerol content, and the hardness of the sample filter rods produced under multiple different glycerol contents and multiple different curing times are obtained to form a third data set. The prediction model is constructed based on the first data set, the second data set, and the third data set.

7. The filter rod production method as described in claim 1, characterized in that, The prediction model is as follows: SD = 65.699 + 0.006010 R + 0.5007 G + 0.33743 M Where SD is the hardness value, R is the suction resistance value, G is the glycerin content, and M is the curing time.

8. The filter rod production method as described in claim 7, characterized in that, The suction resistance adjustment condition model is as follows: A = 0.0601 * (aX) / 10 Where A is the first hardness adjustment value, a is the measured suction resistance value, and X is the suction resistance threshold.

9. The filter rod production method as described in claim 7, characterized in that, The model for adjusting the glycerol content is as follows: B = 0.05007 * (bY) Where B is the second hardness adjustment value, b is the measured glycerol content value, and Y is the glycerol content threshold.

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