A method for improving the conversion efficiency between batches of tobacco thread

Abstract

The present invention discloses a method for improving the efficiency of tobacco silk thread batch conversion. The method utilizes a dual-code network diagram for the tobacco processing industry, combined with inter-batch brand change for tobacco silk production. Key paths and waste sources are identified through the six-hour annotation method. The method utilizes the SMED (Small Medium Enterprise Development) (SMED) conversion method to improve tobacco processing production. The method includes converting online operations to offline operations during brand change in the SMED tobacco production line, reorganizing the tobacco production line process through SMED conversion, and optimizing the flavoring and brand change workflow by converting serial operations to parallel operations. The present invention utilizes the SMED conversion method based on the dual-code network diagram to improve the efficiency of tobacco silk thread batch conversion, thereby improving the efficiency of tobacco silk thread batch conversion and reducing waste of water, electricity, gas, and labor.

Description

Technical Field

[0001] The present invention relates to a method for improving the conversion efficiency between batches of tobacco silk-making lines, in particular to a method for improving the conversion efficiency between batches of tobacco processing silk-making lines by using an SMED conversion method based on a double-code network diagram, and belongs to the field of cigarette silk making. Background Art

[0002] The tobacco production process in a cigarette factory's tobacco-making workshop is complex, with tobacco leaves undergoing two main stages: cutting and drying, and blending and flavoring. Within the tobacco-making line, batches of tobacco leaves enter each process sequentially according to production schedule. Under this assembly line production method, even minimal waiting time increases with each batch.

[0003] After the silk-making workshop enters the production state, the factors affecting the production efficiency of leaf silk thread include: brand change between batches, equipment failure and shutdown, and material transfer time. At present, there is a general problem of low efficiency in brand change between batches of leaf silk thread production in the workshop.

[0004] Therefore, in the face of the problem of low leaf silk thread production efficiency in the workshop, lean management methods should be used to optimize the production mode, reduce the brand change time between leaf thread production batches, and thus improve the brand change efficiency between leaf thread production batches in the silk-making workshop.

[0005] SMED (Single Minute Exchange Dies), often referred to as quick die change, is a method for continuously improving production preparation. This method reduces the time required to change tooling and materials by simplifying and coordinating operations during the die change process. Summary of the Invention

[0006] The technical problems to be solved by the present invention are:

[0007] Tobacco processing lines are generally characterized by long production lines and complex processes. The tobacco leaves undergo two main steps: cutting and drying, and blending and flavoring. Within the production line, different batches of tobacco leaves enter each process sequentially according to the production schedule. Under this assembly line production method, even a small amount of waiting time increases with the number of batches, resulting in wasted water, electricity, gas, and labor due to equipment idling.

[0008] The present invention aims to solve this problem by improving the conversion efficiency between batches of tobacco processing silk thread through a SMED conversion method based on a double-code network diagram, thereby improving the conversion efficiency between batches of tobacco processing silk thread and reducing the waste of water, electricity, gas and labor.

[0009] The main idea of ​​the present invention is:

[0010] Combined with the brand change between tobacco shred batches, a double-code network diagram of the tobacco processing industry is drawn. The six-hour method is used to mark and find the key paths and waste sources. Combined with the SMED model change method, characteristic production improvements in tobacco processing are carried out, including the SMED tobacco shred field brand change process from online work to non-online work, SMED model change to achieve tobacco shred production line process reorganization, and SMED serial to parallel to optimize the flavoring and brand change workflow.

[0011] The technical solution of the present invention is:

[0012] A method for improving the conversion efficiency between batches of tobacco thread, the method comprising the following steps:

[0013] 1. Conduct SIPOC analysis on silk thread;

[0014] 2. Conduct statistical summary of batch conversion work, including:

[0015] (1) There are 6 tasks in the batch change work of the cutting and drying process, which are the material stopping before the drying scale H, the line clearing K, the material discharging from the leaf storage cabinet W, the shredding X, the pre-filling of the drying wire Y, and the feeding and production of the drying machine Z.

[0016] (2) There are eight tasks in the inter-batch changeover of the blending and flavoring process, which are: blending end J, blending completion P, flavoring and silk storage completion Q, blending silk recovery R, ​​flavor return S, flavor pumping T, flavor pre-filling U, and blending silk pre-filling V;

[0017] (3) Summary of the leaf silk line changeover work. For leaf silk line, it includes the cutting and drying process and the blending and flavoring process. When changing brands between batches, there are 14 tasks, namely: stopping the scale before drying H, blending J, production line clearing K, blending completion P, flavoring and storage completion Q, blended silk recovery R, ​​spice return S, spice pumping T, spice pre-filling U, blended silk pre-filling V, leaf cabinet discharge W, shred X, drying silk pre-filling Y, drying machine feeding production Z. The relationship between each task is shown in the following table:

[0018]

[0019]

[0020] 3. Draw a double-code network diagram for the leaf silk batch conversion process

[0021] According to the relationship between each task in the leaf silk line batch change work association table, draw the work flow diagram and the double-code network diagram of the leaf line batch change work;

[0022] 4. Six-hour method to determine the source of leaf thread waste

[0023] For the leaf silk line, the double-code network diagram was calculated and annotated using the six-hour method according to the logical relationship between each task;

[0024] 5.SMED production improvement

[0025] First, a double-code network diagram analysis is conducted to confirm the key work of the leaf silk line.

[0026] The calculation of the brand change time between batches of leaf silk segments is from the time when the scale before the silk drying stops feeding during the production of the previous batch to the time when the silk drying machine is fed into the production of this batch.

[0027] The critical path is determined as: H work, stop the scale before drying the silk → P work, complete the blending → Q work, complete the fragrance and silk storage → W work, discharge the leaf storage cabinet → X work, cut the silk → V work, pre-fill the silk drying → Z work, feed the silk drying machine for production.

[0028] 5.1SMED Online Work to Offline

[0029] The primary function of a buffer cabinet is to ensure a stable supply of incoming materials for subsequent processes, but the current situation increases waiting times between production lines. By rationally utilizing the relationships between production processes and improving production processes, the time it takes to change brands between batches can be effectively reduced.

[0030] The statistics of online and offline processes in the batch change room of leaf silk thread are shown in the following table:

[0031] Job Number Job Title Time (min) Are you currently working online? Can I switch to non-online work? H Stop weighing before drying 0.5 √ × J Blending and finishing 1.5 √ × K Production line clearing 2.5 √ × P Blending completed 8 √ × Q Fragrance and silk storage completed 2.6 √ × R Blended silk recovery 1.5 √ × S Spice recycling 5 √ × T Spice pumping 2 √ × U Spice pre-filled 3 √ × V Pre-filled with blended silk 2 √ × W Leaf cabinet discharge 7 √ √ X shred 4.5 √ × Y Pre-filled dried silk 7 √ × Z Dryer feeding production 0.5 √ ×

[0032] As shown in the table, after implementing segmented start and stop, the leaf storage cabinet in work W discharges material and immediately enters the material preparation state. Because the subsequent work requires much longer than the 7 minutes required for this work, it is planned to convert work W from an online work to an offline work. Pre-loading of work W can be completed before the batch change, and it is not shown in the optimized time-scale flow chart.

[0033] A dual-code network diagram for the transfer of leaf shreds between batches was created for the improved process, enabling the independent operation of the temporary storage cabinet before shredding. This improvement no longer requires waiting for the entire production line to complete before starting the transfer from the leaf storage cabinet to the temporary storage cabinet before shredding. Instead, the transfer begins as soon as the previous batch of shreds is finished, preparing for subsequent production.

[0034] After improvements, the online work of W leaf storage cabinet discharge was successfully converted into non-online work, shortening the brand change time between leaf silk batches and improving the brand change efficiency.

[0035] After the program has been improved, the next batch of material can be fed into the buffer cabinet before the shredded strips are discharged, eliminating the need to wait for the entire batch changeover to begin. Because the batch changeover begins after the buffer cabinet before the shredded strips are discharged and the scale before the strip dryer stops feeding, the buffer cabinet before the shredded strips are fed can be completed and enter the discharge state before the batch changeover begins.

[0036] 5.2SMED conversion to achieve process reorganization

[0037] (1)SMED quick change

[0038] Due to the length of the silk-making line, some equipment runs idle for extended periods after production tasks are assigned, increasing the time required to change brands between batches. As shown in the above analysis, tasks X (slicing) and Y (drying and pre-filling) can be reorganized. Reorganization involves changing the work process and reordering tasks to improve performance. Examples include swapping previous and next steps, replacing manual movements with foot movements, and adjusting the position of machinery and equipment on the production floor.

[0039] The tasks X (shredding) and Y (pre-filling) of wire drying will be relocated from their current locations to immediately after the weighing of wire drying in task H is stopped. We plan to use program improvements to implement segmented start and stop operations, in order to achieve the parallel operation principle based on the SMED rapid changeover lean tool, and reorganize the tasks in the critical path to optimize the changeover time.

[0040] (2) Improve execution

[0041] The cutting and drying process is divided into two sub-processes with the buffer cabinet before drying as the node, namely the cutting sub-process and the drying sub-process.

[0042] The key path after improvement is: H work stops the scale before drying the silk → P work completes the blending → Q work completes the flavoring and silk storage → S work returns the spices → T work pumps the spices → U work pre-fills the spices → Z work feeds the silk drying machine for production.

[0043] After program improvements, the cutting and drying lines were upgraded from a full-line startup to a segmented startup, with Line A thin-sheet drying equipment group 1 and Line A thin-sheet drying equipment group 2. When thin-sheet drying equipment group 1 completes production, preparations for the next batch can begin immediately, without waiting for equipment group 2 to complete. This shifts tasks X (cutting the wire) and Y (pre-loading the wire) from their current locations to immediately after the pre-drying scale stops at Task H. This achieves the goal of optimizing brand changeover time through work reorganization based on SMED analysis.

[0044] 5.3SMED serial to parallel

[0045] Under ideal conditions, the next batch of tobacco would enter the production channel immediately after the previous batch entered the tobacco storage room. However, since it takes a long time to replace the spices in the flavoring tubes, this ideal condition cannot be achieved.

[0046] There is still a serial relationship between leaf thread spice recycling, spice pumping, and spice pre-filling. All three tasks are critical and take up a certain amount of batch change time.

[0047] The series relationship of first returning the material, then pumping, and finally pre-filling is optimized to a parallel relationship. When the previous batch is about to end, the next batch of spices can be pumped and pre-filled, thereby shortening the brand change time.

[0048] Adjusting the production sequence and changing the relationship between pipeline return, overnight pumping and pre-filling from parallel to serial can effectively shorten the running time of the critical path, thereby reducing the time for brand change between batches and improving brand change efficiency.

[0049] Through the improvement of SMED analysis and optimization method, the critical path of blade line change is improved to: 1→3→4→5→11→12 or 1→3→4→5→10→11→12; the key tasks are: H work stops the scale before drying, P work completes blending, Q work completes flavoring and storage, S work returns the spices, T work pumps the spices, U work pre-fills the spices, and Z work feeds the shredded silk machine for production.

[0050] The beneficial effects of the present invention are:

[0051] The present invention improves the conversion efficiency between batches of tobacco processing silk thread by using an SMED conversion method based on a double-code network diagram, thereby improving the conversion efficiency between batches of tobacco processing silk thread and reducing waste of water, electricity, gas and labor. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 : Flowchart of the present invention;

[0053] Figure 2 : Workflow diagram for changing brands between batches of leaf silk thread;

[0054] Figure 3 : Double code network diagram for brand change between batches of leaf silk thread;

[0055] Figure 4 : Six-time method to mark the double-code network diagram of leaf silk line;

[0056] Figure 5 : Leaf silk thread time scale value process analysis diagram;

[0057] Figure 6 : Leaf silk line key work path diagram (the dotted line in the figure represents the key path);

[0058] Figure 7 : Statistics of time occupied by work types;

[0059] Figure 8 : Improve the double-code network diagram of the front leaf silk line (the dotted line in the figure represents the critical path);

[0060] Figure 9 : Improved double-code network diagram of the leaf thread (the dotted line in the figure represents the critical path);

[0061] Figure 10 : Network diagram of the leaf silk thread process before reorganization;

[0062] Figure 11 : Network diagram of brand replacement after the reorganization and improvement of the leaf silk thread process;

[0063] Figure 12 : Double-code network diagram of Yesi line before serial to parallel improvement (the dotted line in the figure indicates the critical path);

[0064] Figure 13 : Double-code network diagram after the Ye silk line was improved from serial to parallel (the dotted line in the figure represents the critical path). DETAILED DESCRIPTION

[0065] Example 1

[0066] The following takes the production of silk thread in a certain cigarette factory as an example, and describes the technical solution and effects of the present invention in further detail with reference to the accompanying drawings.

[0067] 1. SIPOC analysis of silk yarn

[0068] SIPOC analysis is an analysis method for "supplier-input / demand-process-output / demand-customer". The SIPOC worksheet for single batch tobacco production is shown in Table 1.

[0069] Table 1 SIPOC worksheet for single batch tobacco production

[0070]

[0071] 2. Summary of inter-batch conversion work statistics

[0072] (1) Brand change between batches in the cutting and baking process

[0073] The material in the leaf storage cabinet is a semi-finished product after the tobacco thread is loosened and moistened, and the leaf is added to the raw materials. It also serves as the source of material for subsequent cutting, drying, blending, and flavoring. After the required storage time, the leaves in the leaf storage cabinet pass through the production channel to the cutter, which operates according to the set cut width. The tobacco cut through the cutter is stored in the drying buffer cabinet in preparation for the subsequent drying process. During the drying process, the tobacco is first heated by SIROX to ensure the curl and fill value of the dried tobacco. According to the required process standards, the tobacco cut through the drying drum is kept within the specified moisture and temperature range and directly enters the blending and flavoring process. Finally, the finished tobacco is transported through the material channel to the tobacco storage room.

[0074] There are six tasks in total when changing brands between batches in the cutting and drying process, namely stopping the scale before drying, clearing the production line, unloading the leaf storage cabinet, cutting, pre-filling the drying strips, and feeding the drying machine. The summary statistics are shown in Table 2.

[0075] Table 2 Statistics of batch conversion work in cutting and baking process

[0076]

[0077] (2) Brand change between batches in the blending and flavoring process

[0078] There are eight tasks in the blending and flavoring process when changing brands between batches, namely: blending end, blending completion, flavoring and silk storage completion, blending silk recovery, flavor return, flavor pumping, flavor pre-filling, and blending silk pre-filling. The summary statistics are shown in Table 3.

[0079] Table 3 Statistics of brand change work in blending and flavoring process

[0080]

[0081] (3) Summary of the work on changing the brand of Yesi thread

[0082] For leaf yarn, this involves cutting, drying, blending, and flavoring. When changing brands between batches, there are 14 tasks: stopping the scale before drying, finalizing blending, clearing the production line, completing blending, completing flavoring and storing the yarn, recovering the blended yarn, returning the flavor, pumping the flavor, pre-filling the flavor, pre-filling the blended yarn, unloading the leaf cabinet, cutting the yarn, pre-filling the dried yarn, and feeding the yarn dryer. The relationships between these tasks are shown in Table 4.

[0083] Table 4 Summary statistics of leaf silk thread brand replacement work

[0084]

[0085]

[0086] 3. Draw a double-code network diagram for the leaf silk batch conversion process

[0087] According to the relationship between each task in the leaf silk thread batch change work association table, a workflow diagram is drawn as follows Figure 2 shown.

[0088] According to the logical structure of the above figure, draw the double-code network diagram of the blade line batch change work, such as Figure 3 shown.

[0089] 4. Six-hour method to determine the source of leaf thread waste

[0090] For the leaf silk line, according to the logical relationship between each task, the six-hour method was used to calculate and mark the double-code network diagram, such as Figure 4 shown.

[0091] Among them, the work codes are the same as above, namely: H work stops the material scale before drying, J work finishes blending, K work clears the production line, P work completes blending, Q work completes flavoring and storage, R work recovers blended silk, S work returns spices, T work pumps spices, U work pre-fills spices, V work pre-fills blended silk, W work discharges leaf cabinets, X work cuts silk, Y work pre-fills drying silk, and Z work feeds the drying machine for production.

[0092] The working time parameters of the leaf silk thread are shown in Table 5.

[0093] Table 5 Calculation table of various working time parameters of leaf silk thread

[0094]

[0095]

[0096] like Figure 4 In the double-code network diagram of the leaf silk line marked with the six-hour method, the working time parameters are as follows:

[0097] a) ES in the upper left corner is the earliest start time of each task, which is the earliest time the task can start;

[0098] b) EF in the lower left corner is the earliest completion time of each task, which is the corresponding end time under the premise that the task is carried out at the earliest start time;

[0099] c) Middle and upper LS is the latest start time for each task that does not increase the total time for card replacement;

[0100] d) Middle and lower LF is the latest end time of each task that does not increase the total time of card replacement;

[0101] e) TF in the upper right corner is the total time difference, which refers to the maximum extent to which the work can be delayed without increasing the time for changing plates between batches. (Total time difference) = (latest start time - earliest start time) = (latest end time - earliest end time);

[0102] f) FF in the lower right corner is the free time difference, which refers to the maximum extent to which this work can be postponed without affecting the normal progress of the subsequent work. (Free time difference) = (earliest start time of the subsequent work - earliest end time of this work).

[0103] According to the contents of Table 5, the six-hour method was used to calculate and mark the double-code network diagram, such as Figure 4 shown.

[0104] according to Figure 4 The six-hour marking network diagram for the leaf-strip production line shows that the free and total time differences for the seven tasks (H, stopping the scale before drying), P, completing blending, Q, completing flavoring and storing, W, unloading the leaf storage cabinet, X, cutting, Y, pre-filling the dried strands, and Z, feeding the dried strands into the production machine) are all zero. This means that the maximum delay for these tasks is zero! This means that any delay in these tasks will directly affect the batch changeover time of the leaf-strip production line, resulting in increased changeover time.

[0105] Therefore, it can be determined that the critical path when the leaf line is changed is: 1→3→4→5→7→9→11→12; the key tasks are: H work, stopping the scale before drying the silk, P work, completing the blending, Q work, completing the fragrance storage, W work, discharging the leaf cabinet, X work, cutting the silk, Y work, pre-filling the silk, and Z work, feeding the silk drying machine for production.

[0106] The above critical path and key tasks have caused the blade production line to have a long inter-batch changeover time of 10 minutes, which is the bottleneck path that needs to be determined. The next work will focus on improving the bottleneck path to shorten the inter-batch changeover time of the blade production line.

[0107] According to the above content, a time scale process analysis diagram of each work of the blade line is drawn, as shown below: Figure 5 shown.

[0108] The calculation of the brand change time between batches of leaf silk segments is from the time when the scale before the silk drying stops feeding during the production of the previous batch to the time when the silk drying machine is fed and produced. Figure 5The diagram visually shows that the critical path (H, stopping the scale before drying the tofu shreds) → P, completing blending → Q, completing flavoring and storage → W, unloading the leaf storage cabinet → X, cutting → Y, pre-filling the tofu shreds → Z, feeding the tofu shreds into the tofu shreds machine, takes a considerable amount of time. This also results in significant time differences for other non-critical tasks, leading to wasted waiting time. The current situation is that after line K is cleared, it takes 4 minutes to wait; after V, completing blending and pre-filling, it takes 15 minutes; and after U, completing flavoring pre-filling, it takes 8.5 minutes before the next batch can be produced. This results in significant time waste, as well as wasted personnel, waiting time, and energy.

[0109] 5.SMED production improvement

[0110] First, conduct a double-code network diagram analysis, and confirm the key tasks of the leaf silk line as follows Figure 6 shown.

[0111] The calculation of the brand change time between batches of leaf silk segments is from the time when the scale before the silk drying stops feeding during the production of the previous batch to the time when the silk drying machine is fed and produced. Figure 6 The diagram visually shows that the critical path (H, stopping the scale before drying the tofu shreds) → P, completing blending → Q, completing flavoring and storage → W, unloading the leaf storage cabinet → X, cutting → Y, pre-filling the tofu shreds → Z, feeding the tofu shreds into the tofu shreds machine, takes a considerable amount of time. This also results in significant time differences for other non-critical tasks, leading to wasted waiting time. The current situation is that after line K is cleared, it takes 4 minutes to wait; after V, completing blending and pre-filling, it takes 15 minutes; and after U, completing flavoring pre-filling, it takes 8.5 minutes before the next batch can be produced. This results in significant time waste, as well as wasted personnel, waiting time, and energy.

[0112] according to Figure 6 The time-scaled process analysis diagram for each task on the leaf yarn line visually shows that the critical path (H: Stopping the scale before drying the yarn → P: Completing blending → Q: Completing flavoring and storing the yarn → W: Discharging the leaf storage cabinet → X: Cutting the yarn → Y: Pre-filling the yarn → Z: Feeding the yarn dryer) takes a considerable amount of time. This also results in significant time differences for other non-critical tasks, leading to wasted waiting time. The current status is: After line K is cleared, it takes 4 minutes to wait; after V is pre-filled with blended yarn, it takes 15 minutes; and after U is pre-filled with flavoring, it takes 8.5 minutes before the next batch can be produced. This results in significant waste of time, personnel, waiting time, and energy.

[0113] 5.1SMED Online Work to Offline

[0114] The primary function of a buffer cabinet is to ensure a stable supply of incoming materials for subsequent processes, but the current situation increases waiting times between production lines. By rationally utilizing the relationships between production processes and improving production processes, the time it takes to change brands between batches can be effectively reduced.

[0115] The statistics of online and non-online processes in the brand change room of leaf silk thread batches are shown in Table 6.

[0116] Table 6 Statistics of online and offline processes in the batch change room of leaf silk thread

[0117] Job Number Job Title Time (min) Are you currently working online? Can I switch to non-online work? H Stop weighing before drying 0.5 √ × J Blending and finishing 1.5 √ × K Production line clearing 2.5 √ × P Blending completed 8 √ × Q Fragrance and silk storage completed 2.6 √ × R Blended silk recovery 1.5 √ × S Spice recycling 5 √ × T Spice pumping 2 √ × U Spice pre-filled 3 √ × V Pre-filled with blended silk 2 √ × W Leaf cabinet discharge 7 √ √ X shred 4.5 √ × Y Pre-filled dried silk 7 √ × Z Dryer feeding production 0.5 √ ×

[0118] Statistics on time occupied by work types are as follows Figure 7 shown.

[0119] As shown in Table 6, after implementing staged start and stop, the leaf storage cabinet in Work W begins discharging material and immediately enters the stocking state. Because subsequent work requires significantly longer than the 7 minutes required for this task, Work W is planned to be converted from an online task to an offline task. This pre-loading of material for Work W can be completed before the batch change, and thus is not shown in the optimized timescale flow chart.

[0120] The improved flowchart is as follows Figure 8 and Figure 9 shown.

[0121] Programming and improvements were conducted based on the improved flow chart, enabling independent operation of the pre-shredding temporary storage cabinet. This improvement no longer requires waiting for the entire production line to complete before starting the process from the blade storage cabinet to the pre-shredding temporary storage cabinet. Instead, the process begins as soon as the previous batch of shredding is complete, preparing for subsequent production.

[0122] After improvements, the in-line process (discharging from the W leaf storage cabinet) was successfully converted to off-line operation, shortening the time required to change between batches of leaf yarn and improving its efficiency. After the improvements, the time required to change between batches of leaf yarn was reduced from 30.1 minutes to 23.1 minutes.

[0123] Thanks to program improvements, the next batch of material can be fed into Unit 01 after the pre-cutting buffer cabinet has finished discharging, eliminating the need to wait for the entire batch changeover to complete before production can begin. A staged start / stop system has been implemented between Unit 01 and Units 02-05. Because batch changeover begins after the pre-cutting and drying buffer cabinet has finished discharging material and the feed scale in front of the drying machine has stopped, the pre-cutting buffer cabinet can complete feeding and enter the discharge state before batch changeover.

[0124] 5.2SMED conversion to achieve process reorganization

[0125] SMED quick changeover

[0126] Due to the length of the silk-making line, some equipment runs idle for extended periods after production tasks are assigned, increasing the time required to change brands between batches. As shown in the above analysis, tasks X (slicing) and Y (drying and pre-filling) can be reorganized. Reorganization involves changing the work process and reordering tasks to improve performance. Examples include swapping previous and next steps, replacing manual movements with foot movements, and adjusting the position of machinery and equipment on the production floor.

[0127] The team can relocate tasks X (shredding) and Y (pre-filling) from their current locations to immediately after the material is stopped on the pre-shredding scale at task H. They plan to use program improvements to implement segmented start and stop operations, thereby achieving the first principle of parallel operations in the SMED rapid changeover lean tool. This will reorganize tasks on the critical path to optimize changeover time.

[0128] Improved execution: The cutting and drying process is divided into two sub-processes with the pre-drying buffer cabinet as the node, namely the cutting sub-process and the drying sub-process.

[0129] The details of the improved implementation are shown in Table 7.

[0130] Table 7 Improvement implementation details

[0131]

[0132] Comparison of double-code network diagrams before and after SMED rapid changeover improvement Figure 10 and Figure 11 shown.

[0133] Before the improvement, the critical path was: H (stopping the scale before drying the tofu) → P (combining and blending completed) → Q (fragmenting and storing completed) → X (cutting) → Y (pre-filling the tofu) → Z (feeding the tofu dryer). Before the improvement, the brand change time was 23.1 minutes.

[0134] The improved critical path is: H (stopping the scale before drying) → P (completion of blending) → Q (completion of flavoring and storage) → S (returning of flavors) → T (pumping of flavors) → U (pre-filling of flavors) → Z (feeding of the drying machine). The improved changeover time is 21.6 minutes.

[0135] After program improvements, the cutting and drying lines were upgraded from a full-line startup to a segmented startup, with Line A thin-sheet drying equipment group 1 and Line A thin-sheet drying equipment group 2. When thin-sheet drying equipment group 1 completes production, preparations for the next batch can begin immediately, without waiting for equipment group 2 to complete. This shifts tasks X (cutting the wire) and Y (pre-loading the wire) from their current locations to immediately after the pre-drying scale stops at Task H. This achieves the goal of optimizing brand changeover time through work reorganization based on SMED analysis.

[0136] 5.3SMED serial to parallel

[0137] Ideally, the next batch of tobacco would enter the production channel immediately after the previous batch entered the tobacco storage room. However, this ideal situation is not achieved due to the long time required to change the flavoring cartridges. This situation results in a 15-minute wait after blending and pre-filling, and a 4.5-minute wait after the production line is cleared before the next batch can begin. This results in a significant waste of time, which in turn leads to wasted personnel, waiting time, and energy.

[0138] The relationship between leaf thread spice recycling, spice pumping, and spice pre-filling is still serial. All three tasks are critical and take up 10 minutes of batch change time.

[0139] Specifically, the optimization is carried out by improving the sequence of working spice return, spice pumping, and spice pre-filling. The current series relationship of first return, then pumping, and finally pre-filling is optimized to a parallel relationship. When the previous batch is about to end, the next batch of spices can be pumped and pre-filled, thereby shortening the brand change time.

[0140] Serial to parallel conversion diagram Figure 12 and Figure 13 shown.

[0141] Adjusting the production sequence and changing the relationship between pipeline return, overnight pumping and pre-filling from parallel to serial can effectively shorten the running time of the critical path, thereby reducing the time for brand change between batches and improving brand change efficiency.

[0142] Through the improvement of SMED analysis and optimization method, the critical path of blade line change is improved to: 1→3→4→5→11→12 or 1→3→4→5→10→11→12; the key tasks are: H work stops the scale before drying, P work completes blending, Q work completes flavoring and storage, S work returns the spices, T work pumps the spices, U work pre-fills the spices, and Z work feeds the shredded silk machine for production.

[0143] After the improvement from serial to parallel, the card changing time between batches can be effectively shortened, and the card changing time can be reduced from the original 21.6 minutes to 16.6 minutes.

[0144] According to the plan, the production execution procedures were improved, and the workshop also standardized the operating procedures, so that the production parts replacement, material liquid recovery, material liquid pumping and material liquid pre-filling were improved from the original serial relationship to a parallel relationship, which successfully improved the critical path, and transformed material liquid pumping and material liquid pre-filling from critical tasks to non-critical tasks, shortening the replacement time between batches.

Claims

1. A method for improving the conversion efficiency between batches of tobacco thread, characterized in that: The following steps are involved: Step 1, performing SIPOC analysis on the silk thread; Step 2: Statistical summary of batch conversion work, including: (1) There are 6 tasks in the process of changing brands between batches in the cutting and drying process, namely: stopping the scale before drying H, clearing the production line K, unloading the leaf cabinet W, cutting X, pre-filling the drying wire Y, feeding the drying machine Z; (2) There are 8 tasks in the process of changing brands between batches of the blending and flavoring process, namely: blending end J, blending completion P, flavoring silk storage completion Q, blending silk recovery R, ​​flavor return S, flavor pumping T, flavor pre-filling U, blending silk pre-filling V; (3) Summary of the work of changing leaf silk yarn. For leaf silk yarn, it includes the cutting and drying process and the blending and flavoring process. When changing brands between batches, there are 14 tasks, namely: stopping the scale before drying H, blending J, production line clearing K, blending completion P, flavoring and storage completion Q, blending and yarn recovery R, ​​spice return S, spice pumping T, spice pre-filling U, blending and yarn pre-filling V, leaf storage cabinet discharge W, shred X, drying pre-filling Y, drying machine feeding production Z; Step 3: Draw a double-code network diagram for the leaf silk batch conversion process, including: According to the relationship between each task in the leaf silk line batch change work association table, draw the work flow diagram and the double-code network diagram of the leaf line batch change work; Step 4: Determine the source of leaf thread waste using the six-hour method For the leaf silk line, the double-code network diagram was calculated and annotated using the six-hour method according to the logical relationship between each task; Step 5, production improvement based on SMED transformation method, including: Step 5.1, determine the key tasks and critical paths; Step 5.2: SMED online work is converted to non-online work; Step 5.3, SMED changeover to achieve process reorganization; Step 5.4, SMED serial to parallel, includes: optimizing the series relationship of first returning materials, then pumping, and finally pre-filling into a parallel relationship. When the previous batch is about to end, the next batch of spices will be pumped and pre-filled, thereby shortening the brand change time.

2. The method according to claim 1, characterized in that The step 5.1 further includes: (1) Conduct double-code network diagram analysis to confirm the key tasks of the leaf silk line; (2) The calculation of the brand change time between batches of leaf silk segments is from the time when the scale before the silk drying stops during the production of the previous batch to the time when the silk drying machine is fed into the production of the current batch; (3) The critical path is determined as follows: material stopping before drying H → blending completed P → flavoring and storage completed Q → leaf cabinet discharge W → shredding X → pre-filling of drying Y → feeding of drying machine Z.

3. The method according to claim 2, characterized in that The step 5.2 further includes: (1) Count and analyze the online and offline work in the batch change room of leaf silk thread; (2) Find online jobs that can be converted into non-online jobs and convert them through technical means.

4. The method according to claim 3, characterized in that The step 5.3 further includes: (1) SMED rapid changeover Adjust the current locations of the shredded wire cutting (X) and pre-filling (Y) to immediately follow the material stop (H) before the wire drying process. Plans are underway to implement segmented start and stop operations through program improvements. This will enable parallel operation based on the SMED (Simplified Medium-Terminal Development) rapid changeover lean tool, and reorganize tasks along the critical path to optimize changeover time. (2) Improve execution The cutting and drying process is divided into two sub-processes with the pre-drying buffer cabinet as the node, namely the cutting sub-process and the drying sub-process; The key path after improvement is: stopping the scale before drying H → blending completed P → flavoring and storage completed Q → flavor return S → flavor pumping T → flavor pre-filling U → drying machine feeding production Z; After program improvements, the cutting and drying lines were changed from the original whole-line startup to a segmented startup, namely A-line thin plate wire drying machine equipment group 1 and A-line thin plate wire drying machine equipment group 2. When thin plate wire drying machine equipment group 1 completes production, there is no need to wait for equipment group 2 to complete production, and the production preparation work for the next batch can be started directly. As a result, the working wire cutting X and wire drying pre-filling Y are adjusted from the current position to immediately after the working wire drying pre-scale stop H is completed.

5. The method according to claim 4, characterized in that: By improving the SMED analysis and optimization method, the critical path during blade line replacement is improved.

6. The method according to claim 4, characterized in that: Through the improvement of SMED analysis and optimization method, the key tasks are: stopping the scale before drying H, completing blending P, completing flavoring and storing silk Q, returning spices S, pumping spices T, pre-filling spices U, and feeding and producing silk drying machine Z.

7. The method according to claim 1, wherein: The relationship between the 14 tasks summarized in the leaf silk thread brand replacement work is shown in the following table: 。

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