A data characterization method for filter rod circumference control

Abstract

The present invention discloses a data characterization method for filter rod circumference control, including: 1) circumference verification in the startup phase; 2) special working condition verification, splicing and rejection phase; 3) circumference linearity verification; 4) process evaluation verification; 5) periodic verification. This method is used to measure the control situation of the filter rod circumference control system under different working conditions and make targeted improvements, especially to carry out periodic multi-dimensional verification and quality evaluation of the circumference control system to carry out refined control to ensure product quality.

Description

Technical Field

[0001] The invention relates to a data characterization method for filter rod circumference control, belonging to the technical field of circumference control system detection in cigarette filter rod production. Background Art

[0002] In my country's tobacco industry, the filter rod forming process is a very important part of the entire cigarette manufacturing process. The main elements of the filter rod include: acetate fiber bundle, plasticizer, forming paper and glue. The filter rod process tasks mainly consist of: opening and plasticizer application process (bundle unpacking and positioning, bundle pre-tensioning, opening, plasticizer application), forming process (bundle strip forming, adhesive application, rolling forming, overlapping glue application) and output transfer process (cutting, conveying, loading, curing). Among them, forming, as a more critical and important link, directly affects the circumference of the filter rod; the filter rod circumference is an important physical indicator of cigarette products. Excessive fluctuations in the filter rod circumference will directly lead to cigarette leakage, filter tip shedding, wrinkles in the connection part and other connection quality problems. Therefore, the filter rod circumference is the key control indicator of the filter rod forming process, and it is also the difficulty of control.

[0003] Therefore, as mentioned above, the stability and quality of filter rod circumference control are the key links in the filter rod process and the basis for the stability of the filter rod's physical indicators, which in turn will affect the quality of the rolling process and consumer requirements. Therefore, it is the main focus of the tobacco industry's research on filter rod physical indicators and process control.

[0004] At present, the filter rod forming machines used in the domestic tobacco industry include single-channel KDF2, KDF4 and KDF6 and their derivatives, dual-channel DF10 and domestic ZL28 models. The main models are still the KDF2 series and its derivatives. From the perspective of circumference detection and control methods, there are pneumatic circumference detection and control methods and optical (ODM) detection and control methods. The pneumatic circumference detection and control method uses the pneumatic detection method to measure the circumference of the filter rod. The air path is divided into reference air pressure and measurement air pressure. When the filter rod passes through the measuring nozzle, the amount of air passing through the measuring nozzle reflects the size of the filter rod circumference and then controls it. The optical (ODM) detection and control method is an optical diameter detection device that uses optical principles to detect the diameter of the filter rod. It consists of an ODM measurement converter, a component bracket and a computer-assisted analysis and processing system. It mainly completes the task of monitoring the filter rod and correcting the diameter deviation. The existence of dirty optical units in the optical (ODM) detection method will cause detection errors of the measuring device due to dirtiness, thus affecting the control of the physical indicators of the filter rods, and in severe cases, even leading to the production of unqualified filter rods, causing product quality accidents. The existence of dirty optical units in the ODM detection method will cause detection errors of the measuring device due to dirtiness, thus affecting the control of the physical indicators of the filter rods, and in severe cases, even leading to the production of unqualified filter rods, causing product quality accidents.

[0005] From the perspective of the circumference control method in the current filter rod manufacturing process, the KDF2 model is the main model for filter rod production in the current tobacco industry. The circumference control mode is still mainly based on the operator's manual control, that is, the operator extracts samples from the machine and uses the detection instrument to measure the data, and adjusts the molding equipment circumference control module based on the measured data to achieve the purpose of controlling the filter rod circumference. This method cannot well assist the machine operator to discover circumference quality problems and make timely adjustments. There are problems such as lag, high labor intensity and low precision. In addition, due to the long manufacturing age of the KDF2 molding unit, the compact structure and limited expandable space size cannot meet the installation space requirements of more advanced filter rod circumference detection and control devices.

[0006] The Chinese patent with publication number CN202059983U disclosed a laser online controller for the circumference of cigarette filter rods and cigarette sticks on December 7, 2011. It displays the current filter rod circumference value online and automatically adjusts the filter rod circumference. However, the scheme only displays the connection control relationship and does not disclose the relevant detection mechanism. The Chinese patent with publication number CN112890273A disclosed an online dynamic cleaning device for filter rods or cigarette sticks on March 22, 2021. However, this scheme is only to solve the problem of filter rod cleaning, that is, to pre-clean the filter rods before they enter the ODM, so that they have a good cleaning effect, eliminate frequent abnormal adjustments and no adjustments of the ODM, improve the cleanliness of the subsequent production system components and final products of the equipment, and work on improving the stability of the operation of the ODM measurement system of the molding machine.

[0007] In general, in the current filter rod circumference quality control process, the measurement and evaluation are relatively extensive, the scientificity needs to be improved, and the degree of refined research is not high. The main limitations are as follows: 1) The linear changes of the circumference control process cannot be examined; 2) The changes of the circumference under different working conditions cannot be examined, that is, the accuracy of the circumference changes and control under conditions such as equipment speed-up, speed-down, low speed and full speed; 3) There is a lack of scientific evaluation indicators for the advantages and disadvantages of the circumferential control system; 4) The impact of operating aging and overhaul of equipment components is not taken into account, and there is a lack of periodic and multi-dimensional evaluation of the key links of circumferential control.

[0008] In the tobacco industry, with the improvement of the requirements for the entire cigarette process indicators, the requirements for the molding process and product quality are also increasing day by day. Therefore, the stability and quality evaluation of the circular control system in the filter rod molding link are becoming more and more important. Therefore, it is necessary to conduct periodic and multi-dimensional exploration and evaluation to fill the gaps in related aspects and ensure and improve product quality. Summary of the invention

[0009] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a data characterization method for filter rod circumferential control. Through this method, the control status of the filter rod circumferential control system under different working conditions can be measured and targeted improvements can be made, especially to carry out periodic multi-dimensional verification and quality evaluation of the circumferential control system to carry out refined control to ensure product quality.

[0010] To achieve the above object, the present invention provides a data characterization method for filter rod circumference control, which is used to verify the accuracy of circumference control under a fixed circumference control center value, comprising:

[0011] At rated vehicle speed, set the circular control center value;

[0012] Sampling the first batch of filter rods and inspecting the circumference of the first batch of filter rods;

[0013] Based on the circumference of the first batch of filter rods, determine whether the circumference control is accurate under the circumference control center value. If the circumference control center value is not within the set threshold range, replace the set circumference control center value with the circumference of the first batch of filter rods;

[0014] The filter rods of the second batch are sampled and the circumferences of the filter rods of the second batch are detected.

[0015] Prioritize verification of the accuracy of circular control at a fixed circular control center value, including:

[0016] If the circumferential detection mean value of the filter rods of the second batch is within the range of ±0.05mm of the circumferential control center value, and the circumferential detection value of a single filter rod of the second batch is within the range of ±0.15mm of the circumferential control center value, the accuracy of the circumferential control is judged to be qualified.

[0017] Prioritize verification of steady-state control of the filter rod circumference during the startup phase, including:

[0018] Empty the filter rods on the outlet channel of the filter rod making machine;

[0019] During the start-up phase, the rejection amount of the beam and drum is set;

[0020] Continuously sampling in sections at the outlet of the outlet channel;

[0021] The filter rod circumference is tested by an off-line testing instrument to obtain the filter rod circumference mean and circumference standard deviation.

[0022] Preferably, based on the control chart, it is determined whether the control of the filter rod circumference has reached a steady state condition.

[0023] Prioritize verification of changes in filter rod circumference control before and after coil splicing, including:

[0024] Take samples from the filter rods before and after the forming paper coils are spliced;

[0025] The two-sample T test and two-way variance test were performed on the filter rod circumference before and after the forming coil paper was spliced.

[0026] Verify the circumferential changes of the filter rods in the bonding section, including:

[0027] The bonding section is sampled, and the circumference of the filter rod without the bonding section is tested to obtain a single value test value of the circumference.

[0028] Preferably, in verifying the control change of the filter rod circumference before and after the coil paper splicing, if the P value is greater than 0.05, it is determined that there is no significant difference in the control change of the filter rod circumference before and after the coil paper splicing;

[0029] In verifying the circumferential change of the filter rod of the bonding section removal branch, if the circumferential single value detection value is within the range of ±0.15mm of the circumferential control center value, it is determined that the circumferential control of the filter rod of the bonding section removal branch is stable and controlled.

[0030] Prioritize verification of the linearity of the circular control, including:

[0031] At the rated vehicle speed, different circumferential gradients are set, including circumferential control center value -0.10, circumferential control center value center value -0.05, circumferential control center value is the origin, circumferential control center value +0.05 and circumferential control center value +0.10. When the circumferential display value of the rod forming machine is within the range of ±0.15mm of the corresponding circumferential gradient, the filter rod is sampled, and the offline detection instrument detects the circumference of the filter rod to verify its linear compliance and accuracy;

[0032] Verify the accuracy of circular control under different circular control center values, including:

[0033] Get the filter rod circumference, if the linear correlation coefficient R 2 ≥0.98, and the filter rod circumference detection result is within the range of circumference gradient ±0.05mm, then it is judged that the accuracy of circumference control meets the requirements.

[0034] Prioritize the assessment of the process's ability to meet product specifications for high volume production, including:

[0035] During continuous production, filter rods are sampled at intervals, and the circumference of the filter rods is tested by an offline testing instrument. The process capability index Cpk is used to evaluate the process capability level of the filter rod circumference.

[0036] Preferably, in the mass production capacity that the evaluation process meets the product specification requirements, if the process capability index Cpk of the filter rod circumference is ≥ 1.3, it is determined that the mass production capacity that the evaluation process meets the product specification requirements meets the requirements.

[0037] A computer-readable storage medium stores a computer program, which implements the steps of any of the above methods when executed by a processor.

[0038] The beneficial effects achieved by the present invention are:

[0039] The present invention provides a method for periodic multi-dimensional detection and evaluation of a filter rod circumference control system. Periodicity may refer to being carried out at a certain time, such as once every six months or a year, or after an equipment overhaul. This method improves the evaluation of the stability and accuracy of the circumference control system to achieve more effective and accurate control of the filter rod circumference. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a flow chart of the present invention;

[0041] Figure 2 is a line graph of the mean value of the circumference and the suction resistance in the startup stage of the present invention;

[0042] Figure 3 is a line graph of the standard deviation of the circumference and the absorption resistance during the startup phase of the present invention;

[0043] Figure 4 It is a line graph of the set value and mean value of the circular linear verification of the present invention. DETAILED DESCRIPTION

[0044] The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention.

[0045] It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention, they are only used to explain the relative position relationship and movement status of the various components under a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0046] In addition, if the descriptions of "first" and "second" etc. are involved in the present invention, they are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] A detection method for a filter rod circumference control system and quality evaluation, the method comprising the following steps:

[0048] 1) Circumference calibration verification, verify the accuracy of circumference control under fixed circumference control center value, as follows: at rated speed, set the circumference control center value, take the first batch of 20 filter rods through calibration sampling, detect the circumference of the filter rods to obtain the test results, enter the test results into the circumference calibration interface of the machine itself, calibrate, and take the second batch of 50 new samples through the "ODM calibration sampling" function to detect the circumference. The circumference detection mean value is required to be within the range of ±0.05mm of the circumference control center value, and the circumference detection single rod is within the range of ±0.15mm of the circumference control center value.

[0049] 2) Start-up period verification, verify the control of the filter rod circumference and the steady-state during the startup phase, as follows: empty the filter rods on the outlet channel of the filter rod forming machine, set the beam and drum to the normal rejection amount during the startup phase, and continuously take samples in sections at the outlet of the outlet channel, 10 to 30 pieces per group, for a total of 15 to 25 groups, and use offline testing instruments to perform data detection of the filter rod circumference (circumferential mean and circumferential standard deviation). The detection data refers to the control chart to measure the circumferential control and the steady-state. It is required to reach a stable state within the set number of groups (for example, 15 groups) to ensure product quality.

[0050] 3) Verification during special periods, verify the circumference control changes before and after the paper is spliced, and verify the circumference changes of the rejection branch in the bonding section, as follows:

[0051] Verify the control change of the circumference before and after the splicing of the coil paper: take 1 to 3 groups of samples from the 20 pieces before the splicing section of the forming paper and the samples within one minute after the splicing, with 20 pieces in each group, and conduct a two-sample T test and a two-way variance test on the circumference of each group of samples before splicing and each group of samples after splicing to test whether there is a significant difference, and the P value is required to be greater than 0.05;

[0052] Verify the change of circumference before and after the removal of the bonding segment: During normal operation, sample the bonding segment (the sampling quantity can be set in the range of 3-15, and the actual setting value is 15), and detect the circumference of the filter rod without the bonding segment. The circumference single value detection value is required to be within the range of ±0.15mm of the circumference control center value.

[0053] 4) Circular linearity verification, verify the linearity of circular control, verify the accuracy of circular control under different circular control center values, as follows: Under rated vehicle speed, set different circular gradients, which can be set to 5 to 7 groups, such as circular control center value -0.10, circular control center value -0.05, circular control center value as origin, circular control center value +0.05, circular control center value +0.10, etc. Under different circular gradient conditions, take samples when the circumferential display value of the equipment is basically consistent with the corresponding circular gradient, and use offline testing instruments to test the circumference of the filter rod to verify its linear compliance and accuracy.

[0054] Take 20 to 50 filter rods as a group, and take 1 to 5 groups. If the linear correlation coefficient R 2 ≥0.98, and the filter rod circumference detection result is within the range of circumference gradient ±0.05mm, then it is judged that the accuracy of circumference control meets the requirements.

[0055] 5) Process evaluation and verification. Process characteristic evaluation uses the process capability index Cpk to evaluate the process's mass production capacity that meets product specification requirements, based on the physical indicator requirements of product technology, as follows: Under stable production operation conditions, when continuous production is required, interval sampling is carried out within 8 hours, with 10 filter rods as a group, greater than or equal to 25 groups. The circumference of the filter rod is tested by an offline testing instrument, and the process capability index Cpk is used to evaluate the process capability level of the filter rod circumference. The process capability index Cpk of the filter rod circumference is required to be ≥1.3.

[0056] The present invention adopts the above-mentioned detection scheme to achieve the unification and standardization of the detection methods, judgment criteria, etc. of the application amount and related systems in the filter rod production process, and realizes the purposes of effective detection, precision control and periodic verification of the filter rod circumference control system.

[0057] Control chart is a mature mathematical statistics technology in the prior art, which mainly uses mathematical statistics technology to determine whether the circular mean value and SD control are stable or not. T test and two-way variance test are also mature mathematical statistics applications in the prior art. P value is also a mature mathematical statistics indicator in the prior art.

[0058] The present invention has the following effects:

[0059] 1. The test results are highly accurate and reliable;

[0060] 2. The operation methods and steps are clear and highly operable;

[0061] 3. The calculation method is clear and can be used to determine the quality of control in each production link;

[0062] 4. The evaluation method is data-based and highly scientific.

[0063] 1. Circular calibration

[0064] Set the circumference to 19.85mm, take 20 filter rods according to the parameter "ODM calibration sampling", test their circumference, input the test results into the machine, calibrate, and then take 50 samples through the "ODM calibration sampling" function to test the circumference. The test results are shown in the following table:

[0065]

[0066] From the above data, it is considered that the calibration is effective and the results meet the requirements.

[0067] 2. Startup phase verification

[0068] First, observe that the machine is in normal production and the monitoring circle is within the normal product requirements. After stopping, clear the outlet channel and restart, and take samples in chronological order at the outlet channel, 20 in a group, and take 15 groups. The waste smoke removal amount in the SEF startup stage is set to 250. The sampling test results are as follows Figure 2 and Figure 3 shown.

[0069] 3. Verification during special periods

[0070] (1) Circumference before and after splicing

[0071] Take samples of 20 pieces in each group from the 20 pieces before and within one minute after the splicing of the forming paper. Perform a two-sample T test and a two-way variance test on the circumference of the samples before and after splicing to test whether there is a significant difference. The test results are shown in the following table:

[0072] Table 1 Circumference comparison before and after splicing

[0073]

[0074] (2) Circumference before and after the bonding segment is removed

[0075] When the circumference setting value is 19.85mm, during normal operation, sampling is performed through the bonding section sampling (the setting range is 3-15, and the actual setting value is 15), the filter rods containing the bonding section are removed, and the circumference of the remaining filter rods is tested. The test results are shown in the following table:

[0076]

[0077] According to the data in the above table, the circumferential conditions of the paper coil before and after the sticky section is removed meet the requirements.

[0078] In summary, there is no significant difference in the circumference of the filter rod before and after splicing. The circumference before and after splicing meets the requirements.

[0079] 4. Circular linear verification

[0080] At the highest speed, set the circumference to (mm) 19.75, 19.80, 19.85, 19.90, 19.95 respectively. When the displayed value of the equipment is basically consistent with the set value, take samples (20 pieces) and test the circumference to check its linear compliance and accuracy. The test results are shown in the following table:

[0081] Table 3 Circular linearity and accuracy test results

[0082]

[0083] According to the data in the above table, we can draw a graph, such as Figure 4 As shown in the figure, the absolute value of the difference between the calibrated ODM test value and the laboratory test value is less than 0.05mm, and the circumferential linear correlation coefficient R 2 is 0.989, which is consistent with R 2 ≥ 0.98, so it is believed that the ODM of this equipment meets the requirements in terms of accuracy and linearity for circumference detection during the production process.

[0084] 5. Process evaluation and verification

[0085] Under stable production conditions, take samples at intervals during continuous production within 8 hours, with 10 pieces as a group, and no less than 25 groups. Use offline testing equipment to test the circumference and calculate the circumference CPK value as follows:

[0086]

[0087] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0088] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0089] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0090] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A data characterization method for filter rod circumference control, characterized in that: Used to verify the accuracy of circular control under fixed circular control center value, including: At rated vehicle speed, set the circular control center value; Sampling the first batch of filter rods and inspecting the circumference of the first batch of filter rods; Based on the circumference of the first batch of filter rods, determine whether the circumference control is accurate under the circumference control center value. If the circumference control center value is not within the set threshold range, replace the set circumference control center value with the circumference of the first batch of filter rods; Sampling the filter rods of the second batch and detecting the circumference of the filter rods of the second batch; Verify the steady-state control of the filter rod circumference during the startup phase, including: Empty the filter rods on the outlet channel of the filter rod making machine; During the start-up phase, the rejection amount of the beam and drum is set; Continuously sampling in sections at the outlet of the outlet channel; The filter rod circumference is tested by an offline testing instrument to obtain the filter rod circumference mean and circumference standard deviation; Verify the control changes of the filter rod circumference before and after the coil paper splicing, including: Take samples from the filter rods before and after the forming paper coils are spliced; The two-sample T test and two-way variance test were performed on the filter rod circumference before and after the forming coil paper was spliced. Verify the circumferential changes of the filter rods in the bonding section, including: The bonding section is sampled, and the circumference of the filter rod without the bonding section is tested to obtain a single value test value of the circumference; Verify the linearity of circular control, including: At the rated vehicle speed, different circumferential gradients are set, including circumferential control center value -0.10, circumferential control center value center value -0.05, circumferential control center value is the origin, circumferential control center value +0.05 and circumferential control center value +0.

10. When the circumferential display value of the rod forming machine is within the range of ±0.15mm of the corresponding circumferential gradient, the filter rod is sampled, and the offline detection instrument detects the circumference of the filter rod to verify its linear compliance and accuracy; Verify the accuracy of circular control under different circular control center values, including: Get the filter rod circumference, if the linear correlation coefficient R 2 ≥0.98, and the filter rod circumference detection result is within the range of circumference gradient ±0.05mm, it is judged that the accuracy of circumference control meets the requirements.

2. A data characterization method for filter rod circumference control according to claim 1, characterized in that: Verify the accuracy of circular control under fixed circular control center value, including: If the circumferential detection mean value of the filter rods of the second batch is within the range of ±0.05mm of the circumferential control center value, and the circumferential detection value of a single filter rod of the second batch is within the range of ±0.15mm of the circumferential control center value, the accuracy of the circumferential control is judged to be qualified.

3. A data characterization method for filter rod circumference control according to claim 1, characterized in that: Based on the control chart, determine whether the control of the filter rod circumference has reached a steady state.

4. A data characterization method for filter rod circumference control according to claim 1, characterized in that: In verifying the control change of the filter rod circumference before and after the coil paper splicing, if the P value is greater than 0.05, it is determined that there is no significant difference in the control change of the filter rod circumference before and after the coil paper splicing; In verifying the circumferential change of the filter rod of the bonding section removal branch, if the circumferential single value detection value is within the range of ±0.15mm of the circumferential control center value, it is determined that the circumferential control of the filter rod of the bonding section removal branch is stable and controlled.

5. A data characterization method for filter rod circumference control according to claim 1, characterized in that: Evaluate the process's ability to meet product specifications for high volume production, including: During continuous production, filter rods are sampled at intervals, and the circumference of the filter rods is tested by an offline testing instrument. The process capability index Cpk is used to evaluate the process capability level of the filter rod circumference.

6. A data characterization method for filter rod circumference control according to claim 5, characterized in that: In the mass production capacity that the evaluation process meets the requirements of product specifications, if the process capability index Cpk of the filter rod circumference is ≥1.3, it is determined that the mass production capacity that the evaluation process meets the requirements of product specifications meets the requirements.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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