An automated packaging system and method for millet products

Abstract

This invention discloses an automatic packaging system and method for millet products, belonging to the field of food packaging technology. The system includes: a feeding module equipped with a storage hopper with an airflow-assisted guiding device and a variable-speed screw metering device; a weighing module employing a dynamic feedback weighing sensor and a weighing controller to form a closed-loop control, achieving three-stage variable-speed feeding; a forming and filling module including a spirally descending anti-breakage guide trough and a split-type measuring cup filling device; and a sealing and shaping module including a vacuum chamber and an elastic shaping pressure plate. This invention effectively solves the problems of easy bridging and clogging, easy breakage, and low weighing accuracy of millet products through air-assisted bridging, dynamic variable-speed weighing, buffering and guiding, and two-stage pressure vacuum shaping, achieving automated packaging with low breakage, high precision, and high stability.

Description

Technical Field

[0001] This invention relates to the field of food packaging machinery technology, specifically to an automatic packaging system and method for millet products. Background Technology

[0002] Millet products (such as millet, millet powder, and millet snack granules) face two major technical challenges in automated packaging: First, the material has poor flowability and is prone to "bridging" or "arching" in the hopper, leading to interruption or uneven feeding; second, millet products are brittle and hard, and are easily broken during high-speed feeding, weighing, and filling, affecting the appearance and quality of the finished product.

[0003] Traditional screw metering and packaging systems typically employ constant-speed or simple variable-speed feeding, making it difficult to balance packaging speed and weighing accuracy. Especially in the later stages of feeding, excessively rapid deceleration can easily cause material impact breakage or measurement errors. Furthermore, existing measuring cup filling devices and vacuum shaping devices are mostly designed for powdery or large-particle materials. When used directly for millet products, the high impact force and excessively rigid pressure plates often lead to material breakage. Therefore, developing a system capable of achieving low-breakage, high-precision, and high-stability packaging is of significant practical importance. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the purpose of this invention is to provide an automatic packaging system and method for millet products.

[0005] To achieve the aforementioned objective, the technical solution of the present invention is implemented as follows: an automatic packaging system for millet products, comprising: The feeding module includes: a storage hopper for holding millet products; a variable speed screw metering device located at the outlet of the storage hopper, the speed of which is dynamically adjusted by a frequency converter according to the real-time weighing signal; and an airflow auxiliary guiding device, the nozzles of which are set at the conical section of the storage hopper and the inlet of the variable speed screw metering device, for intermittently or continuously spraying low-pressure airflow into the material layer.

[0006] The weighing module includes: a dynamic feedback weighing sensor, which is installed below the feed port of the variable speed screw metering device to collect the weight of the material in real time and generate a weight signal; and a weighing controller, which receives the weight signal and forms a closed-loop control circuit with the frequency converter. Based on the difference between the preset target weight curve and the current weight of the material, the controller calculates and corrects the speed reduction slope of the variable speed screw metering device in the later stage of feeding in real time.

[0007] The molding and filling module includes: a hopper for receiving material from a weighing module; a shatterproof guide trough located below the hopper, the inner wall of which is covered with cushioning material and the trough descends in a spiral shape; and a split measuring cup filling device located at the outlet of the shatterproof guide trough for quantitatively introducing material into the packaging bag.

[0008] The sealing and shaping module includes: a vacuum chamber for containing a packaged bag filled with material; an elastic shaping plate located in the vacuum chamber for applying controllable flexible pressure to the material inside the packaged bag during the vacuuming process; and a heat sealing device for heat sealing the opening of the packaged bag after the vacuum level reaches a preset value.

[0009] As a further improvement, the airflow-assisted guiding device includes: multiple micro-orifice nozzles arranged in layers along the circumferential direction of the inner wall of the cone section of the storage hopper; a pulse airflow generator for generating pulse airflow with a frequency of 0.5Hz-5Hz and a pressure of 0.05MPa-0.2MPa; the angle between the direction of the pulse airflow and the direction of material descent is 30° to 60°. This setup effectively breaks up material bridging without causing millet products to splash or break due to excessive airflow.

[0010] As a further improvement, the weighing controller incorporates a variable-speed feeding curve model, which divides the feeding process into three stages: In the rapid feeding stage, the variable-speed screw metering device operates at a first speed N1, and the dynamic feedback weighing sensor only monitors weight but does not participate in speed regulation; in the buffer feeding stage, when the material weight reaches 60%-80% of the target weight, the weighing controller linearly reduces the speed according to the real-time difference ΔW between the current weight and the target weight, using the formula N = N1 - k1·ΔW, where k1 is the first proportional coefficient; in the finishing feeding stage, when the material weight reaches 90%-95% of the target weight, the weighing controller uses a PID algorithm to fine-tune the speed, and the airflow-assisted guidance device switches to continuous micro-airflow mode. Through segmented control, an optimal balance between speed and accuracy is achieved.

[0011] As a further improvement, the spiral descent angle of the shatterproof guide chute is 15°-25°, and the cushioning material on its inner wall is food-grade silicone or polyurethane foam. A flexible baffle is also installed at the outlet of the shatterproof guide chute. This angle range ensures that the material falls by sliding rather than tumbling, and the flexible baffle further reduces the initial velocity of the material when it leaves the guide chute.

[0012] As a further improvement, the split-type measuring cup filling device includes a left and right half measuring cup that can be opened and closed relative to each other; when closed, the two halves form a complete measuring chamber; when open, the two halves separate to the sides; the inner walls of both the left and right halves are coated with a polytetrafluoroethylene (PTFE) non-stick coating. This structure allows the material to fall vertically into the packaging bag under gravity, avoiding the damage caused by centrifugal ejection in traditional rotating measuring cups.

[0013] As a further improvement, the elastic shaping plate includes an upper plate and a lower plate, corresponding to the top and bottom surfaces of the packaging bag, respectively; the upper plate and / or the lower plate are connected to the drive cylinder via an airbag; during the vacuuming process, the elastic shaping plate first applies a first pressure value of 0.01-0.05 MPa, maintains it for 0.5-1 seconds, and then applies a second pressure value of 0.05-0.1 MPa. This two-stage pressure control, combined with airbag cushioning, gently flattens the material, preventing the grains from being crushed due to instantaneous high pressure.

[0014] As a further improvement, the system also includes an electrostatic elimination module, which is installed at the inlet of the anti-breakage guide trough to generate positive and negative ion airflow to eliminate static electricity generated by material friction and prevent fine particles from adsorbing onto the inner wall of the guide trough.

[0015] The present invention also provides an automatic packaging method for millet products using any of the above-mentioned systems, comprising the following steps: Step 1: Air-assisted bridging feeding. Add millet products into the storage hopper, activate the airflow-assisted guiding device to break up material bridging with pulsed airflow, and simultaneously, the variable-speed screw metering device begins to rotate, forcibly discharging the material from the storage hopper.

[0016] Step 2: Dynamic variable speed weighing. The dynamic feedback weighing sensor collects the weight of the material in real time. The weighing controller controls the frequency converter according to the weight signal, which drives the variable speed screw metering device to perform three stages in sequence: rapid feeding, buffer feeding, and finishing feeding. During the finishing feeding stage, a continuous micro-airflow is started simultaneously.

[0017] Step 3: Buffering and Anti-Breakage Filling. After being weighed, the material falls into the collection hopper and slides down the anti-breakage guide chute in a spiral descent or Z-shaped reversal. It then enters the split-type measuring cup filling device. The measuring cup receives the material in the closed state and fills the packaging bag with low impact when the cup is open.

[0018] Step 4: Vacuum Flexible Shaping and Sealing. The filled packaging bag is sent into the vacuum chamber, and the flexible shaping plate is activated to flexibly flatten the material using a two-stage pressure method. At the same time, a vacuum is drawn, and the heat sealing device completes the sealing after the set vacuum degree is reached.

[0019] As a further improvement to the above method, in step two, the target control accuracy of the finishing feeding stage is within ±0.5% of the set weight; when the weighing exceeds the tolerance three times in a row, the weighing controller automatically triggers the airflow-assisted dredging device to perform a powerful purging action with a pressure of 0.2MPa and a duration of 0.2 seconds to remove the accumulated material at the screw or nozzle.

[0020] As a further improvement to the above method, in step four, the two-stage pressure method is as follows: first, the shaping platen is brought into contact with the material with a pressure of 0.02 MPa and maintained for 0.8 seconds; then, the material is compacted with a pressure of 0.08 MPa and maintained for 0.3 seconds; then the pressure of the platen is released, and heat sealing is performed.

[0021] The beneficial effects of this invention are reflected in: By combining airflow-assisted guidance, a spiral buffer guide trough, a split measuring cup, and an elastic shaping pressure plate, the entire process of feeding, weighing, filling, and shaping millet products is handled flexibly, reducing the breakage rate to less than one-third of traditional systems. A three-stage dynamic variable-speed feeding model, combined with subsequent PID fine-tuning and frequency converter closed-loop control, ensures feeding speed while maintaining stable weighing accuracy within ±0.5%, solving the problem of unstable metering caused by variations in the flowability of millet products. A pulsed airflow-assisted guidance device, combined with a specific angle arrangement of micro-orifice nozzles, effectively breaks up material arching at the cone of the storage hopper without affecting the normal metering of the screw, ensuring the continuity and stability of the feeding process. Attached Figure Description

[0022] In the attached diagram: Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the feeding module of the present invention; Figure 3 This is a schematic diagram of the airflow-assisted diversion device of the present invention; Figure 4 This is a schematic diagram of the weighing module of the present invention; Figure 5 This is a schematic diagram of the molding and filling module of the present invention; Figure 6 This is a schematic diagram of the structure of the split measuring cup filling device of the present invention; Figure 7 This is a half-section schematic diagram of the sealing and shaping module of the present invention; Figure 8 This is a schematic diagram of the airbag distribution of the present invention; Explanation of reference numerals in the attached figures: 10. Feeding module; 11. Storage hopper; 12. Variable speed screw metering device; 13. Frequency converter; 14. Airflow auxiliary guiding device. Micro-orifice nozzle 141, pulse airflow generator 142 Weighing module 20, dynamic feedback load cell 21, weighing controller 22 Molding and filling module 30, hopper 31, anti-breakage guide trough 32, split-type measuring cup filling device 33 321 cushioning material, 322 flexible baffle curtain, 331 left half measuring cup, 332 right half measuring cup Sealing and shaping module 40, vacuum chamber 41, elastic shaping pressure plate 42, heat sealing device 43. Upper pressure plate 421, lower pressure plate 422, airbag 423 Static electricity elimination module 50. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the invention, and not all of them. Unless otherwise specified, the embodiments and features described in this application can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0024] It should be noted that if the embodiments of the invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0025] Furthermore, "multiple" refers to two or more. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the invention.

[0026] Example 1 Reference Figure 1 This embodiment provides an automated packaging system for millet products. This system is particularly suitable for the automated packaging of fragile, irregularly shaped millet crisps, millet crumbs, or dried millet grains.

[0027] The feeding module 10 is the starting part of the system. The storage hopper 11 adopts a conical structure that is wider at the top and narrower at the bottom, and a variable speed screw metering device 12 is installed at its discharge port. The speed of the screw is controlled by a frequency converter 13. An airflow-assisted guiding device 14 is installed on the inner wall of the conical section of the storage hopper 11 and above the screw feed port. This device includes multiple micro-orifice nozzles 141 arranged in layers along the circumference and a pulse airflow generator 142. The pulse airflow generator 142 generates a pulse airflow with a frequency of 2Hz and a pressure of 0.1MPa, and the airflow direction is at a 45° angle to the material falling direction. When millet products form a bridge in the storage hopper 11, the pulse airflow will be ejected from the nozzles 141, breaking the bridge structure from the side and below, allowing the material to resume flow. At the same time, the airflow can also help clean the accumulated material between the screw threads.

[0028] The weighing module 20 is located below the feeding module 10. A high-precision dynamic feedback load cell 21 is directly positioned below the screw feed inlet to receive and weigh the falling material in real time. The weighing controller 22 receives the weight signal from the sensor 21 and forms a closed-loop control with the frequency converter 13. The controller 22 internally contains a variable-speed feeding curve model. Taking a target weight of 500g as an example, the workflow of this model is as follows: Rapid feeding stage: The screw rotates at a high speed of 120 rpm (N1). At this time, sensor 21 only monitors the weight and does not participate in control to achieve the maximum feeding speed. When the weight of the material reaches 300g (i.e., 60%), it switches to the next stage.

[0029] Buffer feeding phase: Controller 22 linearly reduces the rotational speed according to the real-time difference ΔW, using the formula N=120-0.8·ΔW. For example, when the current weight is 400g, ΔW=100g, and the rotational speed drops to 40rpm. This phase ends when the weight reaches 450g (90%).

[0030] Finishing feeding stage: Starting from 450g, controller 22 switches to PID algorithm to fine-tune the screw speed, and at the same time, airflow-assisted guiding device 14 switches from pulse mode to continuous micro-airflow mode with a pressure of 0.02MPa to help the last small amount of material fall smoothly. When the weight reaches 500g±2.5g (±0.5%), feeding stops.

[0031] The molding and filling module 30 includes a hopper 31 for temporarily storing a weighed portion of material. A shatterproof guide trough 32 is connected below the hopper 31; this trough descends spirally at a 20° angle. The inner wall of the trough is covered with a 5mm thick layer of food-grade silicone as a cushioning material 321. At the outlet of the trough, a row of flexible baffle curtains 322, composed of multiple silicone strips, is suspended. After the material is decelerated by the spiral chute, it gently pushes aside the baffle curtains 322 and falls into the lower split-type measuring cup filling device 33. This measuring cup filling device 33 consists of a left half measuring cup 331 and a right half measuring cup 332, which can be opened and closed horizontally under the drive of a cylinder. When closed, it forms a metering chamber with an adjustable volume; when the packaging bag is delivered below, the two halves of the measuring cup quickly separate, and the material falls vertically into the bag with almost no horizontal impact. The inner wall of the measuring cup is coated with polytetrafluoroethylene to prevent millet fragments from sticking together.

[0032] The sealing and shaping module 40 includes an openable and closable vacuum chamber 41. An upper pressure plate 421 and a lower pressure plate 422 are located within the chamber, both connected to their respective drive cylinders via an airbag 423. When the filled packaging bag enters the chamber, vacuuming is initiated, and simultaneously, the upper pressure plate 421 descends under the drive of the cylinder. Low-pressure gas is injected into the airbag 423, causing the upper pressure plate 421 to initially contact the material at a pressure of 0.02 MPa and hold for 0.8 seconds, initially flattening the material. Subsequently, the airbag pressure is increased to 0.08 MPa and held for 0.3 seconds, compressing the material into a flat, brick-like shape. Afterward, the upper pressure plate 421 is slightly raised, and the heat-sealing device 43 heat-seals the bag opening when the vacuum reaches -0.08 MPa. Finally, the vacuum chamber 41 is degassed and opened, releasing the finished packaging bag.

[0033] In addition, an electrostatic elimination module 50 is installed at the inlet of the anti-breakage guide trough 32, which generates positive and negative ion winds to neutralize the static electricity generated by the material during the flow process and prevent millet powder from adsorbing onto the inner wall of the equipment.

[0034] Example 2 This embodiment provides an automatic packaging method for millet products using the above system, including the following specific steps: Step 1: Air-assisted bridge breaking material supply.

[0035] The operator pours the millet crisp granules to be packaged into the storage hopper 11. After the system is started, the airflow-assisted guiding device 14 first outputs a pulsed airflow at a frequency of 1Hz and a pressure of 0.15MPa for 3 seconds to break the initial bridging. Subsequently, the variable speed screw metering device 12 starts to rotate at a preset rapid feeding speed, forcibly discharging the material.

[0036] Step 2: Dynamic speed-changing weighing.

[0037] The dynamic feedback weighing sensor 21 collects weight data at a frequency of 100 times per second. The weighing controller 22 performs three-stage control. When the target weight is 200g, the rotation speed is 150rpm during the rapid feeding stage; after the weight reaches 140g (70%), it enters the buffer stage and linearly reduces the speed; after the weight reaches 188g (94%), it enters the finishing stage, which uses PID control, and the airflow is switched to a continuous micro-airflow of 0.01MPa. When three consecutive weighing results exceed 200g±1g (±0.5%), the controller 22 automatically triggers the airflow auxiliary guiding device 14 to perform a powerful purging at 0.2MPa for 0.2 seconds to clean the screw and nozzle.

[0038] Step 3: Buffering and anti-breakage filling.

[0039] The weighed material falls into the collecting hopper 31 and then enters the spiral-descending anti-breakage guide trough 32. The material slides in an S-shape or spiral on the inner wall of the silicone material, gradually decreasing in speed. Upon reaching the outlet, the flexible baffle curtain 322 further absorbs its kinetic energy. The material then enters the metering chamber formed by the closed left half-measuring cup 331 and right half-measuring cup 332. When the packaging bag is in place, the cylinder drives the two half-measuring cups to open rapidly, and the material falls vertically into the bag by its own weight.

[0040] Step 4: Vacuum flexible shaping and sealing.

[0041] The packaging bag filled with material is fed into the vacuum chamber 41 and the bag opening is secured. The vacuum pump is started to evacuate air, and the elastic shaping plate 42 is activated simultaneously. The plate 42 first presses the material with a pressure of 0.02 MPa for 0.8 seconds, allowing the material to spread naturally under low pressure; then the pressure is increased to 0.08 MPa and maintained for 0.3 seconds, compacting the material into a regular shape. Afterward, the plate 42 retracts 1 mm to release pressure but maintains its position. When the vacuum level in the chamber reaches -0.09 MPa, the heat sealing device 43 is energized to heat seal the bag opening. After heat sealing, the plate 42 is fully reset, the chamber is inflated and opened, and the finished product is discharged.

[0042] Through the above system and method, this embodiment successfully achieved high-speed, low-damage, and high-precision packaging of millet crisp granules. The packaging speed can reach 40-60 bags / minute, the finished product damage rate is less than 0.5%, and the weighing accuracy is stable within ±0.3%.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0044] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An automatic packaging system for millet products, characterized in that, include: The feeding module (10) includes: Storage hopper (11) is used to hold millet products; The variable speed screw metering device (12) located at the discharge port of the storage hopper (11) has its rotation speed dynamically adjusted by the frequency converter (13) according to the real-time weighing signal; The airflow-assisted guiding device (14) has a nozzle (141) located at the conical section of the storage hopper (11) and the feed inlet of the variable speed screw metering device (12) for intermittently or continuously spraying low-pressure airflow into the material layer. Weighing module (20), comprising: A dynamic feedback weighing sensor (21) is installed below the discharge port of the variable speed screw metering device (12) to collect the weight of the dropped material in real time and generate a weight signal. The weighing controller (22) receives the weight signal and forms a closed-loop control loop with the frequency converter (13). Based on the difference between the preset target weight curve and the current material weight, it calculates and corrects the speed reduction slope of the variable speed screw metering device (12) in the later stage of material feeding in real time. Molding and filling module (30), comprising: The material collection hopper (31) receives material from the weighing module (20); The anti-breakage guide trough (32) located below the collection hopper (31) has its inner wall covered with buffer material (321), and the trough descends in a spiral shape; A split-type measuring cup filling device (33) is provided at the outlet of the anti-breakage guide trough (32) for quantitatively introducing materials into the packaging bag; Sealing and shaping module (40), which includes: Vacuum chamber (41) for containing a packaged bag filled with material; The elastic shaping plate (42) located in the vacuum chamber (41) applies controllable flexible pressure to the material inside the packaging bag during the vacuuming process; The heat sealing device (43) heat seals the opening of the packaging bag after the vacuum level reaches a preset value.

2. The automatic packaging system for millet products according to claim 1, characterized in that, The airflow-assisted diversion device (14) includes: Multiple micro-orifice nozzles (141) are arranged in layers along the circumferential direction of the inner wall of the cone section of the storage hopper (11); A pulsed airflow generator (142) is used to generate pulsed airflow with a frequency of 0.5Hz-5Hz and a pressure of 0.05MPa-0.2MPa; The angle between the direction of the pulsed airflow and the direction of material falling is 30° to 60°.

3. The automatic packaging system for millet products according to claim 1, characterized in that, The weighing controller (22) has a built-in variable speed feeding curve model, which divides the feeding process into three stages: Rapid feeding stage: The variable speed screw metering device (12) operates at the first speed N1, and the dynamic feedback weighing sensor (21) only monitors the weight but does not participate in speed regulation; Buffer feeding stage: When the weight of the material reaches 60%-80% of the target weight, the weighing controller (22) linearly reduces the rotation speed according to the real-time difference ΔW between the current weight and the target weight, according to the formula N = N1 - k1·ΔW, where k1 is the first proportional coefficient; Finishing and feeding stage: When the weight of the material reaches 90%-95% of the target weight, the weighing controller (22) uses the PID algorithm to fine-tune the rotation speed, and the airflow-assisted guiding device (14) switches to continuous micro-airflow mode.

4. The automatic packaging system for millet products according to claim 1, characterized in that, The spiral descent angle of the anti-breakage guide trough (32) is 15°-25°, the buffer material (321) of its inner wall is food-grade silicone or polyurethane sponge, and a flexible baffle curtain (322) is provided at the outlet of the anti-breakage guide trough (32).

5. An automatic packaging system for millet products according to claim 1, characterized in that, The split-type measuring cup filling device (33) includes: The left half of the measuring cup (331) and the right half of the measuring cup (332) can be opened and closed relative to each other; When in the closed state, the two halves of the measuring cup form a complete measuring cavity; When in the open position, the two halves of the measuring cup separate to the sides; The inner walls of both the left half measuring cup (331) and the right half measuring cup (332) are coated with a polytetrafluoroethylene non-stick coating.

6. The automatic packaging system for millet products according to claim 1, characterized in that, The elastic shaping plate (42) includes: The upper pressure plate (421) and the lower pressure plate (422) correspond to the top and bottom surfaces of the packaging bag, respectively; The upper pressure plate (421) and / or lower pressure plate (422) are connected to the drive cylinder via an air bag (423); During the vacuuming process, the elastic shaping plate (42) first presses with a first pressure value of 0.01-0.05MPa, maintains it for 0.5-1 seconds, and then presses with a second pressure value of 0.05-0.1MPa.

7. The automatic packaging system for millet products according to claim 1, characterized in that, Also includes: An electrostatic elimination module (50) is installed at the inlet of the anti-breakage guide trough (32) to generate positive and negative ion airflow.

8. An automatic packaging method for millet products using the system described in any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1: Pneumatic bridge breaking material supply Millet products are put into the storage hopper (11), and the airflow-assisted guiding device (14) is activated to break the material bridging with pulse airflow. At the same time, the variable speed screw metering device (12) starts to rotate, forcibly discharging the material from the storage hopper (11). Step 2: Dynamic speed-changing weighing The dynamic feedback weighing sensor (21) collects the weight of the material in real time. The weighing controller (22) controls the frequency converter (13) according to the weight signal, and drives the variable speed screw metering device (12) to perform three stages in sequence: rapid feeding, buffer feeding and finishing feeding. During the finishing feeding stage, continuous micro airflow is started simultaneously. Step 3: Buffering and Fragmentation Prevention Filling After being weighed, the material falls into the collection hopper (31), and slides down along the spiral descent or Z-shaped return anti-breakage guide trough (32) at a reduced speed. Then it enters the split-type measuring cup filling device (33). The measuring cup receives the material in the closed state and fills the packaging bag with low impact in the open state. Step 4: Vacuum Flexible Shaping and Sealing The filled packaging bag is sent into the vacuum chamber (41), and the elastic shaping plate (42) is activated to flexibly flatten the material in a two-stage pressure manner. At the same time, a vacuum is drawn, and the heat sealing device (43) completes the sealing after the set vacuum degree is reached.

9. The automatic packaging method for millet products according to claim 8, characterized in that, In step two, the target control accuracy of the finishing feeding stage is within ±0.5% of the set weight; when the weighing exceeds the tolerance three times in a row, the weighing controller (22) automatically triggers the airflow-assisted dredging device (14) to perform a powerful purging action with a pressure of 0.2MPa and a duration of 0.2 seconds.

10. The automatic packaging method for millet products according to claim 8, characterized in that, In step four, the secondary pressure method is as follows: first, the shaping plate (42) is brought into contact with the material with a pressure of 0.02 MPa and maintained for 0.8 seconds; then, the material is compacted with a pressure of 0.08 MPa and maintained for 0.3 seconds; then the pressure of the plate is released and heat sealing is performed.

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