Tobacco viscoelasticity tester and method for measuring the same

Abstract

This invention relates to the technical field and discloses an instrument and method for measuring the viscoelastic properties of tobacco shreds. The instrument includes a measuring component, a pressure applying component, a displacement detection component, and a control module. The measuring component includes a measuring container and a pressure detection element, while the pressure applying component includes a drive mechanism and a pressure probe. The control module is electrically connected to the pressure detection element, the displacement detection component, and the pressure applying component. During the movement of the pressure probe towards the tobacco sample, the control module compares the pressure value detected by the pressure detection element with a preset contact threshold to identify the contact moment between the pressure probe and the tobacco sample, and determines the displacement corresponding to that moment as the zero-compression point. Based on the zero-compression point, a compression test is performed, and pressure and displacement data are collected. This technical solution improves the repeatability and comparability of measurement results and enables automated, high-precision measurement of the viscoelastic properties of tobacco shreds and acquisition of dynamic characteristic data during the compression process.

Description

Technical Field

[0001] This invention relates to the field of tobacco processing technology, specifically to an instrument and method for measuring the viscoelastic properties of tobacco shreds. Background Technology

[0002] In cigarette production, the viscoelastic properties of tobacco shreds are typically used to measure their tightness. Essentially, this reflects the time-pressure change per unit mass of tobacco shreds under specific volume conditions, determining multiple final quality indicators such as the density, weight per cigarette, draw resistance, hardness, and combustion uniformity of the formed cigarette [YC / T 152-2001, YC / T 163-2003]. In large-scale industrial production, cigarette manufacturers often set extremely narrow process control bandwidths (±1% or even lower) for target filler values ​​based on their formula, equipment capabilities, and market positioning. This is to maximize raw material utilization, reduce costs, and implement safety standards for extruded cigarettes while ensuring sensory consistency.

[0003] Currently, the industry generally uses four main technical approaches to measure the viscoelastic properties of tobacco: The manual static compression method, based on standards, uses weights to apply constant pressure to a specified mass of tobacco shreds and calculates the filling value by measuring the compressed volume. Its advantages are its direct principle and high degree of conformity with standards. However, it suffers from significant drawbacks such as low efficiency, large human error, reliance on operator skill for repeatability, and the inability to obtain dynamic curves of the compression process. These disadvantages make it difficult to meet the demands of modern industry for efficiency and comprehensive data.

[0004] The methods include the gravimetric method and the X-ray volumetric method. The gravimetric method calculates filling characteristics by measuring the pressure or weight change of tobacco as it passes through the rollers. While this increases detection speed, the dynamic compression process differs from standard static compression conditions, sometimes raising questions about data comparability. The X-ray volumetric method measures tobacco volume using the principle of X-ray penetration. While it allows for rapid, non-contact measurement, it faces challenges such as expensive equipment, the need to address radiation source safety and protection issues, complex maintenance, and difficulties in public acceptance.

[0005] Near-infrared spectroscopy (NIR) prediction method. This method makes rapid predictions by establishing a mathematical model between spectral characteristics and fill values. However, the model relies heavily on calibration with a large number of representative samples. For new production areas, new formulas, or tobacco with large fluctuations in physical properties, the model's generalization ability and prediction accuracy may decrease. Essentially, it is an indirect, black-box estimation that is difficult to provide an explanation of the physical mechanism and process curves.

[0006] In addition, some scholars have tried to introduce machine vision and CT imaging, which can provide two-dimensional or three-dimensional structural information of tobacco shreds and have unique value in research. However, they are currently mostly in the laboratory verification stage and have problems such as extremely high equipment costs, complex data processing, and slow measurement speed. They are still far from industrial online applications.

[0007] In summary, existing technical solutions struggle to achieve a balance in terms of measurement efficiency, accuracy and stability, richness of process information, safety, and industrial applicability. The industry has long lacked a testing instrument and method that can achieve automated, high-precision, and highly repeatable measurements while adhering to static standard principles, and simultaneously acquire the viscoelastic characteristic curves of the entire tobacco compression process. Summary of the Invention

[0008] To address the shortcomings or defects of existing technologies, this invention aims to provide a tobacco viscoelasticity measuring instrument and its measuring method. Under the premise of ensuring that the measurement principle is consistent with the static compression standard, it solves the technical problem that the compression starting point of tobacco samples is inconsistent due to differences in the filling state, thus affecting the repeatability and comparability of measurement results. At the same time, it realizes the automated and high-precision measurement of tobacco viscoelasticity and the acquisition of dynamic characteristic data of the compression process.

[0009] To achieve the above objectives, a first aspect of the present invention provides a tobacco viscoelasticity measuring instrument, comprising: The measuring assembly includes a measuring container for holding a tobacco sample and a pressure detection element disposed below the measuring container; A pressure-applying component, disposed above the measuring component, includes a driving mechanism and a pressure-applying probe connected to the driving mechanism; the pressure-applying component is used to apply pressure to the tobacco shreds to be tested inside the measuring container; A displacement detection component, connected to the pressure application component, is used to detect the displacement of the pressure application probe during the pressure application process; The control module is electrically connected to the pressure detection element, the displacement detection assembly, and the pressure application assembly, respectively. During the movement of the pressure probe toward the tobacco sample, the contact moment between the pressure probe and the tobacco sample is identified based on the comparison between the pressure value detected by the pressure detection element and the preset contact threshold, and the displacement corresponding to that moment is determined as the zero compression position. Compression tests are performed using the compression zero-position control pressure probe, and pressure and displacement data are collected to obtain the viscoelastic properties of the tobacco.

[0010] In some embodiments, the drive mechanism includes a drive motor and a linear module; The drive motor is connected to the linear module for transmission; the pressure probe is located at the output end of the linear module and is driven by the drive motor through the linear module to perform vertical linear motion.

[0011] In some embodiments, it also includes: Base; A bracket, extending vertically on the base, is provided; the pressure application component and the displacement detection component are mounted on the bracket. The housing is disposed on the base and at least partially surrounds the bracket, the pressure application component, and the displacement detection component; The display module is mounted on the housing and is electrically connected to the control module.

[0012] In some embodiments, the control module is capable of performing at least one of the following operating modes: In constant pressure compression mode, the movement of the pressure probe is controlled to make the pressure value detected by the pressure detection element reach and maintain a preset target pressure value, and the displacement change data detected by the displacement detection component over time is recorded. In the shaping compression mode, the pressure probe is controlled to move to a preset target displacement and maintain that displacement, while recording the pressure change data over time.

[0013] In some embodiments, in the constant pressure compression mode, the control module performs closed-loop control of the drive mechanism based on the feedback signals from the pressure detection element and the displacement detection component to maintain the target pressure value.

[0014] This invention also provides a method for determining the viscoelastic properties of tobacco shreds, using the aforementioned tobacco shred viscoelastic property measuring instrument, comprising the following steps: Step S1: Load a pre-set mass of tobacco sample into the measuring container; Step S2: Control the pressure probe to move toward the tobacco sample and detect the pressure value of the pressure detection element in real time; Step S3: When the pressure value detected by the pressure detection component exceeds a contact threshold for the first time, the corresponding displacement detected by the displacement detection component is determined as the zero compression position. Step S4: Based on the zero-compression position, control the pressure probe to perform a compression test on the tobacco sample and collect pressure and displacement data. In some embodiments, the compression test in step S4 includes any of the following methods: (a) Constant pressure compression mode, control the pressure detected by the pressure detection element to reach and maintain the target pressure value, and record the displacement detected by the displacement detection component over time; (b) Shape compression mode, control the displacement of the pressure probe to reach and maintain the target displacement value, and record the pressure change over time detected by the pressure detection element.

[0015] In some embodiments, when constant pressure compression is used, the target pressure value is changed, and steps S1 to S4 are repeated to obtain displacement data corresponding to different pressure conditions and establish the relationship between pressure and displacement.

[0016] In some embodiments, when shape compression is used, the target displacement value is changed, and steps S1 to S4 are repeated to obtain pressure data corresponding to different displacement conditions and establish the relationship between displacement and pressure.

[0017] In some embodiments, the viscoelastic properties of tobacco are evaluated based on the relationship between pressure and displacement.

[0018] Compared with the prior art, the automatic method and instrument for determining the tobacco filling value provided by the present invention have the following advantages: Compared with existing technologies, this invention effectively eliminates the problem of inconsistent initial heights of tobacco samples caused by differences in their packing conditions by comparing the pressure value detected by the pressure sensor with a preset contact threshold during the movement of the pressure probe towards the tobacco sample. The moment of contact between the pressure probe and the tobacco sample is identified, and the displacement corresponding to that moment is determined as the zero-compression point. Using a unified zero-compression point as a displacement reference for subsequent compression tests ensures consistent compression starting conditions across different samples or batches, significantly improving the repeatability and comparability of measurement results.

[0019] This invention automates the pressure application process and enables real-time acquisition of pressure and displacement signals by controlling the pressure application component, pressure detection component, and displacement detection component through a control module. During compression testing, it continuously acquires data on pressure and displacement changes over time, thus providing not only steady-state measurement results but also reflecting the dynamic viscoelastic properties of tobacco, such as creep and stress relaxation, during compression. Compared to traditional measurement methods that only obtain a single result value, this invention significantly enhances the richness of measurement information and the value of data analysis.

[0020] Meanwhile, due to the use of a control method that combines pressure detection and displacement detection, the pressure state can be adjusted according to the feedback signal during the compression process, making the pressure process more stable. This helps to improve measurement accuracy and reduce the influence of human operation factors, further enhancing the consistency and reliability of measurement results.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0022] Figure 1 This is a flowchart of the constant pressure compression mode and the shape compression mode of the present invention; Figure 2 This is a schematic diagram of the overall structure of one embodiment of the tobacco viscoelasticity measuring instrument of the present invention; Figure 3 yes Figure 2 A schematic diagram of the internal structure.

[0023] Explanation of reference numerals in the attached figures 1. Base; 2. Bracket; 3. Measuring component; 4. Pressure application component; 5. Displacement detection component; 6. Housing; 7. Display module; 31 Measuring container; 32 Pressure testing device; 41 Drive motor; 42 Linear module; 43 Pressure probe. Detailed Implementation

[0024] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0025] In this invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the orientation in the assembled and used state. "Inner" and "outer" refer to the inner and outer sides relative to the outline of each component itself.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] like Figure 2 and Figure 3 As shown, the tobacco viscoelasticity tester mainly includes a base 1, a bracket 2, a measuring component 3, a pressure application component 4, a displacement detection component 5, a control module (not shown separately in the figure, usually integrated in the electrical control box), a housing 6, and a display module 7.

[0028] The base 1 serves as the supporting foundation for the entire instrument. The bracket 2 is fixed to the base 1 and extends vertically upwards. The pressure application component 4 and the displacement detection component 5 are mounted on the bracket 2.

[0029] The measuring component 3 includes a measuring container 31 and a pressure detection element 32. The measuring container 31 is used to hold the tobacco sample, and its inner diameter is preferably 58 mm to 62 mm. The pressure detection element 32 is preferably a pressure sensor with a range of 0–500 N and a resolution of no more than 0.1 N, which is arranged directly below the measuring container 31 to detect the force on the tobacco sample during the compression process.

[0030] The pressure application assembly 4 is mounted on the bracket 2, located above the measuring assembly 3, and includes a drive motor 41, a linear module 42, and a pressure probe 43. The drive motor 41 (preferably a servo motor) is connected to the linear module 42, converting rotational motion into high-precision vertical linear motion. The pressure probe 43 is mounted at the output end of the linear module 42, directly above the measuring container 31, and its diameter is preferably 53mm to 57mm, matching the inner diameter of the measuring container 31 to reduce boundary effects. The pressure probe 43 is used to apply controllable pressure to the tobacco sample inside the measuring container 31. Furthermore, the measuring container 31 has graduated walls to assist in recording the initial height of the tobacco.

[0031] The displacement detection component 5 is used to detect the displacement of the pressure probe 43, i.e., the compression height. A grating ruler or encoder is preferably used, with a resolution preferably not greater than 1 μm.

[0032] The housing 6 is mounted on the base 1, providing protection for the internal components. The measuring component 3 and the pressure probe 43 are located outside the housing 6, while other components are located inside the housing 6. The display module 7 (such as a touch screen) is mounted on or embedded in the outer wall of the housing 6, and is electrically connected to the control module for human-machine interaction, parameter setting, process monitoring, result display, execution control, and data acquisition and processing.

[0033] The control module is electrically connected to the pressure detection element 32, the displacement detection component 5, and the pressure application component 4 via the display module 7. The control module is programmed to execute the control logic and data processing functions described in subsequent embodiments, such as controlling the drive mechanism to drive the pressure application probe 43 to perform a compression action based on feedback signals from the pressure detection element 32 and the displacement detection component 5, and acquiring measurement data related to the viscoelastic properties of tobacco.

[0034] The control module performs closed-loop control of the pressurization process based on pressure and displacement signals to regulate and maintain pressure or displacement. In some embodiments, proportional-integral-derivative (PID) control, fuzzy control, or a combination thereof can be used to achieve the above control function. The closed-loop control described above can be implemented using conventional control algorithms in the art.

[0035] like Figure 1As shown in (a), the constant pressure compression mode measurement method is performed using the above-mentioned tobacco viscoelasticity measuring instrument. The overall idea is to control the movement of the pressure probe 43 so that the pressure value detected by the pressure detection element 32 reaches and maintains a preset target pressure value, and record the displacement change data over time detected by the displacement detection component 5.

[0036] To be more specific: S1 Sample loading: Before the test begins, a predetermined mass m of tobacco shreds, which has been fully equilibrated under constant temperature and humidity conditions, is accurately weighed and then evenly and loosely loaded into the measuring container 31. Compaction of the tobacco shreds is avoided to ensure consistency in the initial state of the test.

[0037] Before compression begins, the control module performs a software zeroing operation on the output signal of the pressure sensor to eliminate the influence of the tare weight of the measuring container 31 and the tray, ensuring the accuracy of subsequent pressure readings.

[0038] S3 contact self-identification: The control module controls the drive motor 41 to operate, driving the pressure probe 43 to slowly press down at a preset constant low speed via the linear module 42. During this process, the control module synchronously reads the pressure value P of the pressure detection element 32 in real time. When the system first detects that the pressure value P exceeds a preset small contact threshold (preferably 0.1N to 1N, for example 0.5N), it determines that the pressure probe 43 has just contacted the surface of the tobacco sample. At this moment, the control module records the real-time reading of the displacement detection component 5 (i.e., the grating ruler) and calibrates it as the "compression zero point" of this compression process, recording the distance from the pressure probe 43 to the bottom of the measuring container 31 at this time as h0. This step achieves automatic and accurate identification of the compression starting point, eliminating the initial error caused by the difference in tobacco filling height, thereby improving the consistency and accuracy of the test.

[0039] After the S4 closed-loop constant pressure compression completes the zero-point calibration, the control module continues to drive the pressure probe 43 to press down, gradually increasing the pressure so that the real-time pressure P detected by the pressure detection element 32 quickly and smoothly reaches and stabilizes at the preset target pressure value. During this stage, the control module synchronously acquires displacement value h and pressure value P at a high speed with a period of ≤1ms.

[0040] When the pressure value P reaches the preset pressure value When compression stops, record the height of the pressure probe 43 from the bottom of the measuring container 31 at this point. h 1. The volume of the tobacco at this moment is:

[0041] Where d is the inner diameter of the measuring barrel.

[0042] It should be noted that the "rapid" mentioned above does not refer to the mechanical pressing speed of the pressure probe 43, but rather to the dynamic response speed of the control system to the pressure setpoint. Based on high-frequency sampling and control algorithms, the control module drives the pressure probe to perform extremely sensitive micro-precision adjustments, enabling the actual detected pressure to quickly track and reach the preset target value with a very short adjustment time and minimal overshoot. .

[0043] This requirement for a "rapid" response is based on the physical properties of tobacco as a typical viscoelastic material. During the compression process, tobacco undergoes both elastic deformation and time-dependent viscous flow simultaneously. If the pressure build-up process is slow, significant stress relaxation and creep will occur during the long ramp-up phase before reaching the target pressure. This leads to a severe deviation between the final "stable" mechanical state and the preset initial target state, distorting the subsequent "time-displacement" curve and failing to accurately reflect the true creep characteristics under constant load. Therefore, achieving rapid closed-loop pressure build-up is crucial to quickly traverse the pressure transition phase before significant relaxation occurs in the tobacco, establishing an accurate and consistent initial mechanical benchmark for subsequent constant pressure maintenance tests. This is one of the key technical requirements for ensuring high accuracy and repeatability of the entire viscoelastic property measurement results.

[0044] S5 real-time measurement (pressure holding and data acquisition), when pressure achieve Afterward, the system enters the pressure holding phase. The control module dynamically fine-tunes the position of the pressure probe 43 to continuously resist the pressure decay caused by tobacco creep, thereby maintaining the pressure. Precisely maintained at Nearby. Throughout this holding phase, the system continuously records the displacement of the pressure probe 43. Over time The change was used to obtain the time-displacement curve. This curve reflects the creep behavior of tobacco shreds under constant load. When the rate of displacement change falls below a set threshold, the system is considered to have reached a steady state, and the final stable displacement is recorded. At this point, the volume of tobacco shreds under that pressure can be calculated. .

[0045]

[0046] Where d is the inner diameter of the measuring container 31. The distance between the pressure probe 43 and the bottom of the measuring container 31 is the height.

[0047] S6 resets the test. After a single test is completed, the control module automatically controls the pressure probe 43 to rise smoothly and return to the safe initial standby position, ready for the next test.

[0048] S7 repeats the measurement; to obtain the complete compression characteristics of the tobacco, the target pressure value can be changed. (For example, setting multiple increasing or decreasing pressure points), repeat steps S1 to S6 for the same batch of samples or parallel samples. Through this series of tests, a set of different... Below The data was used to plot the pressure-displacement relationship curve of the tobacco sample, providing rich data for in-depth analysis of its mechanical properties.

[0049] like Figure 1 As shown in (b), a method for measuring the shape-compression mode is performed using a tobacco viscoelasticity measuring instrument. The overall approach is to control the pressure probe 43 to move to a preset target displacement value and maintain its position, while simultaneously recording the curve of the pressure value detected by the pressure detection element 32 changing over time. The specific steps are as follows: S1 Sample loading: Before the test begins, a predetermined mass m of tobacco shreds that has been fully balanced under constant temperature and humidity conditions is accurately weighed and then evenly and loosely loaded into the measuring container 31.

[0050] Before compression begins, the control module performs a software zeroing operation on the output signal of the pressure sensor to eliminate the influence of the tare weight of the measuring container and tray, ensuring the accuracy of subsequent pressure readings.

[0051] S3 contact self-identification: The control module controls the drive motor 41 to operate, driving the pressure probe 43 to slowly press down at a preset constant low speed via the linear module 42. During this process, the control module synchronously reads the pressure value P of the pressure detection element 32 in real time. When the system first detects that the pressure value P exceeds a preset small contact threshold (preferably 0.1N to 1N, for example 0.5N), it determines that the pressure probe 43 has just contacted the surface of the tobacco sample. At this moment, the control module records the real-time reading of the displacement detection component 5 (i.e., the grating ruler) and officially calibrates it as the "compression zero point" of this compression process, recording the distance from the pressure probe 43 to the bottom of the measuring container at this time as h0. This step achieves automatic and accurate identification of the compression starting point, eliminating the initial error caused by the difference in tobacco filling height, thereby improving the consistency and accuracy of the test.

[0052] After the S4 closed-loop compression test and zero-point calibration, the control module continues to control the pressure probe 43 to press down, and reads the displacement h of the pressure probe 43 and the pressure value P of the pressure sensor in real time, so that the displacement of the pressure probe 43 (the amount of compression calculated from the zero point) reaches the user-preset target displacement value. (This value corresponds to the target compression volume). The system compares the displacement detection values ​​in real time. and ,when achieve At that time, the control module immediately sends a command to the drive mechanism, causing it to stop precisely and lock in the current position.

[0053] S5 performs real-time measurement. Under the condition that the position of the pressure probe 43 is kept strictly fixed (i.e., the deformation of the tobacco sample is constant), the stress inside the tobacco will relax over time. At this time, the system continuously records the pressure P detected by the pressure detection element 32 over time at high speed. The changes in pressure are used to obtain the time-pressure curve. This curve characterizes the stress relaxation properties of tobacco under constant deformation. Once the pressure drop rate falls below a set threshold and stability is achieved, the final stable pressure is recorded. .

[0054] S6 Reset: After the test is completed, the control module controls the pressure probe 43 to automatically reset.

[0055] S7 Repeat Measurement: By changing the target displacement value By repeating the test, a series of stable pressure data under different degrees of compression can be obtained, and then the displacement-pressure relationship curve of the tobacco sample can be plotted.

[0056] At the mechanical structure level, the technical solution of this invention employs a high-rigidity linear module combined with a coaxial self-calibrating pressure head design, effectively suppressing errors caused by lateral force and probe tilt. In terms of signal detection, by combining a grating ruler with a resolution of 0.5µm and a precision piezoelectric pressure sensor with a range of 500N, the system can obtain a high-quality dynamic feedback signal with a signal-to-noise ratio higher than 20dB.

[0057] In terms of control implementation, the control module performs closed-loop regulation of the compression process based on displacement and pressure signals, and automatically calibrates the zero-compression position when the pressure probe contacts the sample, thereby ensuring the consistency of the compression start position. Through the combination of the above structure and control method, the compression process can have good stability and repeatability, and can effectively reduce the impact of displacement fluctuations on the measurement results.

[0058] Compared to traditional static measurement methods using weights, this method increases the efficiency of a single measurement by more than three times and reduces the standard deviation of the filling value measurement to 0.02 cm³·g. - Within ¹; Compared with existing online rolling or X-ray volume methods, this solution completely avoids the safety and management risks brought by radioactive sources, and its measurement principle and calculation formula system fully comply with industry static standards (such as YC / T 152), thereby achieving seamless connection and unified traceability between factory online data and laboratory calibration data.

[0059] Furthermore, first viscoelastic property data is obtained through constant pressure compression measurement method; second viscoelastic property data is obtained through shape-fixed compression measurement method; and a comprehensive evaluation is performed based on the first viscoelastic property data and the second viscoelastic property data.

[0060] In practical applications, constant pressure compression scanning tests (obtaining pressure-displacement curves) and shape-fixed compression scanning tests (obtaining displacement-pressure curves) can be performed sequentially on the same sample. By comprehensively utilizing the creep and relaxation information contained in these two sets of curves, the viscoelastic properties of tobacco shreds (such as elastic modulus, viscous component, relaxation time spectrum, etc.) can be evaluated more comprehensively and profoundly. This provides accurate and quantitative data guidance for cigarette formulation design, optimization of tobacco processing parameters (such as flavoring and additives, drying intensity, stem pressing parameters), and prediction of cigarette rolling quality (such as empty end rate, end-burst amount).

[0061] The tobacco viscoelasticity measuring instrument and method of the present invention improves the repeatability and comparability of measurement results by setting a contact threshold recognition mechanism and determining the compression zero point, thus ensuring that the compression starting position remains consistent under different loading conditions. Furthermore, through the cooperation of the pressure application component and the displacement detection component, automatic control and data acquisition of the tobacco compression process are achieved, which not only improves measurement efficiency and accuracy but also obtains dynamic process data reflecting the viscoelasticity of the tobacco.

[0062] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0063] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0064] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. An instrument for measuring the viscoelastic properties of tobacco shreds, characterized in that, The instrument for measuring the viscoelastic properties of tobacco shreds includes: The measuring component (3) includes a measuring container (31) for holding a tobacco sample and a pressure detection element (32) disposed below the measuring container (31). The pressure application component (4) is disposed above the measuring component (3) and includes a driving mechanism and a pressure probe (43) connected to the driving mechanism; the pressure application component (4) is used to apply pressure to the tobacco shreds to be tested in the measuring container (31); The displacement detection component (5) is connected to the pressure application component (4) and is used to detect the displacement of the pressure application probe (43) during the pressure application process; The control module is electrically connected to the pressure detection element (32), the displacement detection component (5), and the pressure application component (4), respectively; During the process of the pressure probe (43) moving towards the tobacco sample, the contact time between the pressure probe (43) and the tobacco sample is identified based on the comparison result between the pressure value detected by the pressure detection element (32) and the preset contact threshold, and the displacement corresponding to that time is determined as the zero compression position. Compression tests are performed based on the compression zero-position control pressure probe (43), and pressure and displacement data are collected to obtain the viscoelastic properties of tobacco.

2. The tobacco viscoelasticity measuring instrument according to claim 1, characterized in that, The drive mechanism includes a drive motor (41) and a linear module (42). The drive motor (41) is connected to the linear module (42) for transmission; the pressure probe (43) is located at the output end of the linear module (42) and is driven by the drive motor (41) through the linear module (42) to perform vertical linear motion.

3. The tobacco shred viscoelasticity measuring instrument according to claim 1, characterized in that, Also includes: Base (1); A bracket (2) is provided on the base (1) extending vertically, and the pressure application component (4) and the displacement detection component (5) are mounted on the bracket (2). The outer casing (6) is disposed on the base (1) and at least partially surrounds the bracket (2), the pressure application component (4) and the displacement detection component (5). The display module (7) is disposed on the housing (6) and electrically connected to the control module.

4. The tobacco shred viscoelasticity measuring instrument according to claim 1, characterized in that, The control module is capable of performing at least one of the following operating modes: In constant pressure compression mode, by controlling the movement of the pressure probe (43), the pressure value detected by the pressure detection component (32) reaches and maintains the preset target pressure value, and records the displacement change data detected by the displacement detection component (5) over time. In the shaping compression mode, the pressure probe (43) is controlled to move to a preset target displacement and maintain that displacement, and the pressure change data over time is recorded.

5. The tobacco shred viscoelasticity measuring instrument according to claim 4, characterized in that, In the constant pressure compression mode, the control module performs closed-loop control on the drive mechanism based on the feedback signals of the pressure detection element (32) and the displacement detection component (5) to maintain the target pressure value.

6. A method for determining the viscoelastic properties of tobacco shreds, characterized in that, Using the tobacco viscoelasticity measuring instrument according to any one of claims 1-5, the following steps are included: Step S1: Load a sample of tobacco shreds of a preset mass into the measuring container (31). Step S2: Control the pressure probe (43) to move toward the tobacco sample and detect the pressure value of the pressure detection element (32) in real time; Step S3: When the pressure value detected by the pressure detection component (32) exceeds a contact threshold for the first time, the corresponding displacement detected by the displacement detection component (5) is determined as the zero compression position. Step S4: Based on the zero compression position, control the pressure probe (43) to perform a compression test on the tobacco sample and collect pressure and displacement data.

7. The method for determining the viscoelastic properties of tobacco shreds according to claim 6, characterized in that, The compression test described in step S4 includes any of the following methods: (a) Constant pressure compression mode, the pressure detected by the pressure detection component (32) reaches and maintains the target pressure value, and the displacement detected by the displacement detection component (5) changes over time; (b) In the shape compression mode, the displacement of the pressure probe (43) is controlled to reach and maintain the target displacement value, and the pressure detected by the pressure detection element (32) is recorded over time.

8. The method for determining the viscoelastic properties of tobacco shreds according to claim 7, characterized in that, When constant pressure compression is used, the target pressure value is changed, and steps S1 to S4 are repeated to obtain displacement data corresponding to different pressure conditions and establish the relationship between pressure and displacement.

9. The method for determining the viscoelastic properties of tobacco shreds according to claim 7, characterized in that, When using shape compression, change the target displacement value and repeat steps S1 to S4 to obtain pressure data corresponding to different displacement conditions and establish the relationship between displacement and pressure.

10. The method for determining the viscoelastic properties of tobacco shreds according to claim 8 or 9, characterized in that, The viscoelastic properties of tobacco shreds are evaluated based on the relationship between pressure and displacement.

Images