A device for determining the total migration of a food contact material

Abstract

The present application relates to the technical field of food contact material safety detection, and particularly relates to a food contact material total migration amount determination device. The device comprises a vacuum adjustment module, a water tank module, a sample test bin module, an electronic balance bin module, a central controller and a sample migration device. The sample test bin module is provided with a sealed test cavity, a sample bearing table and a control console, and the control console can adjust the temperature, pressure and humidity in the cavity. The vacuum adjustment module is connected to the left side of the test bin and used for vacuumizing. The water tank module is arranged on the top and used for storing distilled water and delivering water vapor to adjust the humidity. The electronic balance bin module is connected to the right side and used for weighing the sample in a constant temperature and humidity environment. The sample migration device can transfer the sample from the test bin to the balance bin. The device integrates vacuum drying, humidity adjustment, environmental balance, sample migration and precise weighing, reduces the manual transfer times of the sample between different devices, and significantly improves the automation degree of the determination process.

Description

Technical Field

[0001] This invention relates to the field of food contact material safety testing technology, and in particular to a device for measuring the total migration of food contact materials. Background Technology

[0002] During contact with food, non-volatile substances contained in food contact materials and articles may migrate into the food or food simulants. Total migration is one of the important indicators for evaluating the safety of food contact materials, and the result is usually expressed as the mass of non-volatile substances migrating per unit food contact area. When determining the total migration according to relevant national food safety standards, it is necessary to accurately measure the mass of the sample before and after the migration test, and calculate the total migration based on the initial mass, final mass, and actual contact area of ​​the sample.

[0003] For paper, cardboard, cellulose products, some hygroscopic polymers, and food contact materials with porous structures, sample mass is easily affected by ambient temperature and humidity. During the transfer of samples from a conditioned or dried environment to the weighing environment, the samples may absorb or release moisture, leading to changes in the weighing results. Especially when using food simulants such as olive oil for total migration determination, it is necessary to first determine whether the sample is moisture-sensitive. If the sample is moisture-sensitive, the moisture content needs to be adjusted before and after the migration test to reduce the impact of changes in the sample's own moisture content on the total migration determination results.

[0004] Existing methods for determining moisture sensitivity and adjusting moisture content typically require the separate use of equipment such as vacuum drying ovens, constant temperature and humidity chambers, and electronic balances. Test personnel must repeatedly handle and transfer samples between these different devices, recording temperature, humidity, vacuum level, processing time, and weighing data. This approach presents at least the following problems: First, when samples are transferred between different devices, they are exposed to the external environment. Changes in ambient temperature and humidity may cause the samples to absorb moisture or lose water, resulting in a discrepancy between the mass of the sample after leaving the treatment environment and the mass at the time of weighing. This, in turn, affects the results of moisture sensitivity assessment and total migration measurement.

[0005] Secondly, the steps of vacuum drying, constant humidity adjustment, environmental equilibration and weighing are independent of each other. Operators need to switch the equipment on and off, move the samples and enter the weighing data multiple times. The degree of automation is low, the test cycle is long, and it is easy to cause human errors such as sample misplacement, data omission or inconsistent processing time.

[0006] Third, ordinary electronic balances are usually set up directly in the laboratory environment. Fluctuations in laboratory temperature and humidity, air flow, static electricity, and changes in sample temperature can all affect weighing stability, making it particularly difficult to meet the requirements of continuous weighing and judgment of small mass differences.

[0007] Fourth, the vacuum, temperature, and humidity control systems in existing equipment are usually independent of each other, making it difficult to form a closed-loop control according to the test procedure. When the vacuum or humidity fluctuates, manual intervention is required, which is not conducive to ensuring the consistency of test conditions between different batches.

[0008] Fifth, if the test chamber and weighing chamber are connected for a long period of time, the vacuum drying or high humidity treatment environment will interfere with the constant temperature and humidity environment of the electronic balance chamber; if they are completely separated, then manual removal and transfer of samples are required. Therefore, how to reliably isolate the test chamber and the electronic balance chamber while achieving automatic migration is a technical problem that needs to be solved to achieve fully automated measurement.

[0009] In addition, the water level and quality of the distilled water in the tank also affect the humidity control effect. Existing humidity generating equipment usually requires manual water replenishment and lacks continuous monitoring of conductivity, total organic carbon content, and liquid level, which may affect the stability of the test environment due to insufficient water volume or changes in water quality.

[0010] Therefore, it is necessary to provide a device for measuring the total migration of food contact materials that integrates vacuum drying, constant humidity regulation, constant temperature and humidity weighing, automatic sample migration, data acquisition, and program control into one unit. This device can automatically complete the moisture sensitivity judgment, moisture content adjustment, and weighing process while reducing the contact between the sample and the external environment, thereby improving the accuracy, repeatability, and automation of the total migration measurement. Summary of the Invention

[0011] The purpose of this invention is to overcome the shortcomings of the prior art and provide a device for measuring the total migration of food contact materials. By setting up a vacuum conditioning module, a water tank module, a sample test chamber module, an electronic balance chamber module, a central controller, and a sample migration device, vacuum drying, humidity regulation, environmental equilibration, sample migration, and precision weighing are integrated into the same device, reducing the number of times samples need to be manually transferred between different devices and improving the automation level of the measurement process.

[0012] To achieve the above objectives, the technical solution adopted by this invention is as follows: This invention discloses a device for determining the total migration amount of food contact materials, including a vacuum conditioning module, a water tank module, a sample test chamber module, an electronic balance chamber module, a central controller, and a sample migration device. The sample test chamber module includes a test chamber shell, a sealed test chamber, a sample support platform, a control console, and a test chamber door. The test chamber shell has a square structure, and a square sealed test chamber is provided on the upper part of its outer wall. The sealed test chamber is provided with a sample support platform for placing samples, and the test chamber door is provided at the front opening of the sealed test chamber. The control console can adjust the temperature, pressure, and humidity inside the sealed test chamber; the vacuum regulation module is connected to the lower left side wall of the sample test chamber module and is used to evacuate the sample test chamber module; the water tank module is located on the top of the sample test chamber module and is used to store distilled water and supply water vapor to the sample test chamber module to regulate the humidity inside the chamber; the electronic balance chamber module is connected to the right side wall of the sample test chamber module and is used to weigh the sample in a constant temperature and humidity environment; the sample in the sample test chamber module can be transferred to the electronic balance chamber module by the sample transfer device.

[0013] The electronic balance chamber module includes a balance chamber shell, a sealed balance chamber cavity, a high-precision electronic balance, a balance chamber cavity door, and a constant temperature and humidity system. The sealed balance chamber shell has a square structure, with a square sealed balance chamber cavity located on the upper part of its front wall. The front opening of the sealed balance chamber cavity is provided with the balance chamber cavity door. The high-precision electronic balance is located at the bottom of the inner cavity of the sealed balance chamber. The constant temperature and humidity system is located inside the sealed balance chamber cavity to maintain the environment inside the balance chamber at 25°C±0.5°C and relative humidity at 50%±2%. A migration port is provided between the sealed balance chamber cavity and the sealed test chamber, and the sample migration device migrates the sample from the sealed test chamber to the sealed balance chamber cavity through the migration port.

[0014] The sample transfer device includes a roller linear guide system and a robotic arm. The base of the robotic arm is fixed on the linear guide slider of the roller linear guide system. The linear guide slider slides in cooperation with the linear slide rail of the roller linear guide system. One end of the slide rail is fixed to the top of the sealed test chamber, and the other end passes through the top of the transfer port and is fixedly connected to the top of the sealed balance chamber. The robotic arm can move from the sealed test chamber to the sealed balance chamber through the roller linear guide system.

[0015] A migration door capable of closing the migration opening is provided on the right side. The migration door is located inside the sealed balance chamber and is driven to move vertically by a drive mechanism. The drive mechanism includes a cylinder seat, a piston rod, a connecting block, a drive slider, and a drive rail. The bottom of the balance chamber housing is provided with a balance control housing with a hollow square structure and an open front end. The cylinder seat is fixed to the left side of the inner cavity of the balance control housing. The bottom end of the piston rod can move vertically along the inner cavity of the cylinder seat, and the top end of the piston rod passes through the bottom of the sealed balance chamber and connects to the middle of the bottom end of the connecting block. The inner wall of the connecting block is fixedly connected to the middle of the outer wall of the migration door. The length of the connecting block is greater than the width of the migration door. Drive sliders are provided on the inner walls at both ends of the connecting block. The drive rails are provided on both sides of the left side wall of the sealed balance chamber and are arranged vertically. The drive sliders slide in cooperation with the drive rails.

[0016] The linear slide rail has a square cross-section, with semi-circular grooves on the lower sides of its two side walls. The linear guide slider has a square structure, with a square groove at its top for insertion of the linear slide rail. The inner walls of the square groove have snap-fit ​​parts matching the shape of the groove on both sides. The linear slide rail is positioned at the sliding door with a notch of the same thickness as the sliding door. Vertical rods are connected to the top two sides of the sliding door, and a horizontal rod is connected between the top ends of the vertical rods. The top of the sealed balance chamber has a horizontal rod hole for the horizontal rod to pass through. A connecting slide rail is located at the bottom of the horizontal rod. The length of the connecting slide rail is equal to the thickness of the sliding door, and the cross-sectional shape of the connecting slide rail is the same as that of the linear slide rail. The length of the vertical rod is greater than the height of the sliding door.

[0017] The sample support platform includes a support rod, a placement rod, a support frame, and spacer rods. Four rods are fixed vertically to the front and rear sides of the left and right walls of the sealed test chamber. Several placement rods are equally spaced vertically on the outer wall of the support rod. The support frame is a square frame structure set on the placement rod. Several spacer rods are equally spaced between the inner walls of the support frame. The sample is placed on the top of the spacer rod.

[0018] The top of the outer wall of the test chamber shell is connected to the bottom of the outer wall of the water tank module via a quick-connect mechanism. This quick-connect mechanism includes two identical connecting units, which are respectively fixed to the bottom of the two side walls of the water tank module and the top of the two side walls of the test chamber shell. The two connecting units are symmetrically arranged about the midpoint of the connection point. Each connecting unit includes a base, an arc block, an outer guide ring, an inner guide ring, and a lever. The base has a square structure with an arc hole in its center that matches the shape of the arc block. The inner guide ring is connected to the side wall of the arc block, and the inner wall of the inner guide ring is flush with the inner wall of the arc block. The thickness of the inner guide ring is less than the thickness of the arc block; the inner wall of the inner guide ring is connected to the outer guide ring, the inner wall of the outer guide ring is flush with the inner wall of the inner guide ring, the thickness of the outer guide ring is less than the thickness of the arc block, and the thickness of the outer guide ring is greater than the thickness of the inner guide ring; the inner wall of the base is respectively provided with an inner guide groove for the rotation of the inner guide ring and an outer guide groove for the rotation of the outer guide ring, the outer guide groove is connected to the arc hole through the inner guide groove, the top of the base is provided with a groove for the rotation of the lever, the bottom of the groove is connected to the outer guide groove, and the bottom end of the lever passes through the groove and is connected to the side wall of the outer guide ring.

[0019] The vacuum regulation module includes a multi-stage vacuum pump group, a vacuum buffer tank, a vacuum sensor, a vacuum solenoid valve group, and a vacuum pipeline. The multi-stage vacuum pump group includes a coarse vacuum pump and a fine vacuum pump connected in sequence. One end of the vacuum buffer tank is connected to the multi-stage vacuum pump group via the vacuum pipeline, and the other end is connected to the vacuum interface of the sealed test chamber via the vacuum solenoid valve group. The vacuum sensor is installed in the vacuum pipeline and / or the sealed test chamber to detect the vacuum level in the sealed test chamber. The volume of the vacuum buffer tank is not less than three times the volume of the sealed test chamber. The multi-stage vacuum pump group is used to adjust the pressure in the sealed test chamber from atmospheric pressure to 1.3 kPa. The vacuum sensor is a capacitive thin-film vacuum gauge with a measurement accuracy of not less than ±0.1 kPa.

[0020] The water tank module includes a distilled water storage tank, an ultrasonic atomizer, a humidity generator, a dehumidifier, a circulating water pump, a water level sensor, a water quality monitoring unit, an automatic water replenishment system, and a humidity delivery pipeline. The ultrasonic atomizer is located inside or connected to the distilled water storage tank. The humidity generator is connected to the humidity interface of the sealed test chamber via the humidity delivery pipeline, and is used to deliver atomized and vaporized or gas-liquid separated humid gas to the sealed test chamber. The dehumidifier is connected to the sealed test chamber to reduce the humidity within the chamber. The ultrasonic atomizer uses high-efficiency... The system uses high-frequency ultrasonic oscillation, producing atomized particles with a particle size no greater than 5μm. The dehumidification device includes a semiconductor refrigeration dehumidification component and a molecular sieve adsorption dehumidification component. The water quality monitoring unit is used to detect the conductivity and total organic carbon content of the distilled water, and the water level sensor is used to detect the liquid level in the distilled water storage tank. The automatic water replenishment system is connected to an external pure water source via a water replenishment pipeline, and a water replenishment solenoid valve is installed on the water replenishment pipeline. When the water level sensor detects that the liquid level in the distilled water storage tank is lower than the preset liquid level, the central controller controls the water replenishment solenoid valve to open, so as to automatically replenish distilled water to the distilled water storage tank.

[0021] The central controller is electrically or communicatively connected to the vacuum conditioning module, water tank module, sample testing chamber module, electronic balance chamber module, and sample transfer device. The central controller receives sensor detection signals from each module and sends control commands to each module according to a preset test program. The central controller is also connected to a vacuum sensor, water level sensor, water quality monitoring unit, temperature sensor, humidity sensor, and pressure sensor within the sealed test chamber, temperature and humidity sensor within the constant temperature and humidity system, and a high-precision electronic balance. Based on the collected temperature, humidity, pressure, vacuum, water level, water quality, and mass data, the central controller controls the multi-stage vacuum pump group, vacuum solenoid valve group, ultrasonic atomizer, humidity generator, dehumidifier, automatic water replenishment system, constant temperature and humidity system, drive mechanism, and robotic arm. The central controller includes a control processing unit, data acquisition unit, data storage unit, communication unit, human-machine interface unit, and alarm unit. The control processing unit executes preset vacuum drying, constant humidity conditioning, sample transfer, and weighing programs. The data storage unit stores sample information, environmental parameters, weighing data, equipment operating status, and alarm information.

[0022] The beneficial effects of this invention are as follows: 1. This invention integrates vacuum drying, humidity control, environmental equilibration, sample transfer, and precision weighing into a single device by setting up a vacuum conditioning module, a water tank module, a sample testing chamber module, an electronic balance chamber module, a central controller, and a sample transfer device. This reduces the number of times samples need to be manually transferred between different devices and improves the automation level of the measurement process.

[0023] 2. The sealed test chamber can adjust the temperature, pressure and humidity according to the preset program, so that the same test chamber can perform both vacuum drying program and constant humidity adjustment program. Therefore, it can be adapted to both vacuum drying method and constant humidity method test modes, and can be used for moisture sensitivity judgment and moisture content adjustment before and after migration test.

[0024] 3. The sealed balance chamber is maintained in an environment of 25℃±0.5℃ and 50%±2% relative humidity by a constant temperature and humidity system. The high-precision electronic balance weighs under relatively stable temperature and humidity conditions, which can reduce the impact of laboratory environmental fluctuations and changes in sample temperature and moisture content on the weighing results, and improve the stability and comparability of continuous weighing data.

[0025] 4. The sample transfer device, through the cooperation of a robotic arm and a roller linear guide system, automatically transfers the sample from the sealed test chamber to the sealed balance chamber. After weighing, the sample can be returned to the sealed test chamber. This structure reduces manual contact with the sample and the sample's exposure time to the external environment, helping to prevent the sample from absorbing moisture, losing water, or becoming contaminated during the transfer process.

[0026] 5. The migration door can close the migration opening when not in the migration state, isolating the sealed test chamber from the sealed balance chamber and preventing the vacuum, high temperature, or high humidity environment in the test chamber from affecting the constant temperature and humidity environment of the balance chamber. When sample migration is required, the drive mechanism moves the migration door vertically to open the migration channel, achieving coordinated control of inter-chamber isolation and sample passage.

[0027] 6. The top of the transfer door is equipped with vertical bars, horizontal bars, and connecting slide rails. When the transfer door moves to the open position, the connecting slide rails fill the gap formed by the linear slide rails at the transfer door, thus forming a continuous movement track for the robotic arm. When the transfer door closes, the connecting slide rails move away from the gap with the transfer door, allowing the transfer door to close the transfer opening. This structure balances track continuity and the requirements for sealing and isolation of the compartment, improving the stability of sample transfer.

[0028] 7. The slots on both sides of the linear guide rail cooperate with the locking parts inside the linear guide rail slider to limit the slider's offset and disengagement relative to the linear guide rail, so that the robotic arm remains stable during cross-compartment movement and reduces the risk of sample tilting or falling.

[0029] 8. The sample support stage adopts a multi-layer placement structure with multiple spacer bars within the support frame, enabling the simultaneous placement of multiple samples or sample cups. This spacing facilitates the flow of air, water vapor, and heat around the samples, improving the consistency of processing conditions for different samples, and also making it easier for the robotic arm to grasp and place the samples.

[0030] 9. The vacuum regulation module employs a multi-stage vacuum pump group, with a coarse vacuum pump and a fine vacuum pump working in sequence, and is equipped with a vacuum buffer tank with a volume not less than three times the volume of the sealed test chamber, which can buffer and stabilize the vacuuming process. Combined with a vacuum solenoid valve group and a capacitive thin-film vacuum gauge, the pressure in the sealed test chamber can be adjusted to approximately 1.3 kPa, improving the accuracy of vacuum control.

[0031] 10. The water tank module is equipped with an ultrasonic atomizer, a humidity generator, and a dehumidifier, which can both replenish water vapor to the sealed test chamber and dehumidify when the humidity is higher than the target value, thus forming a two-way humidity control. The atomized particles with a diameter of no more than 5μm are conducive to the dispersion of moisture in the airflow, improving the uniformity and response speed of humidity control.

[0032] 11. The water level sensor, water quality monitoring unit, and automatic water replenishment system can monitor the liquid level, conductivity, and total organic carbon content of the distilled water storage tank, respectively, and automatically replenish water when the liquid level is lower than the preset value, thereby reducing the frequency of manual maintenance and reducing the impact of water shortage or abnormal water quality on humidity control results.

[0033] 12. The water tank module and the sample test chamber module are connected by a quick-connect mechanism. The operator can control the rotation of the corresponding connecting parts by turning the lever, so as to realize the quick assembly or disassembly of the water tank module, which is convenient for water replenishment, cleaning, maintenance and replacement.

[0034] 13. The central controller can centrally collect temperature, humidity, pressure, vacuum, water level, water quality and mass data, and control the vacuum pump, valve group, humidity generator, dehumidification device, constant temperature and humidity system, transfer door and robotic arm according to the preset program to realize closed-loop adjustment of test conditions and automatic connection of sample processing and weighing process. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure in the closed state of the migration door in this invention. Figure 1 ; Figure 2 This is a cross-sectional view of the sliding door in the closed state in this invention; Figure 3 This is a schematic diagram of the structure in the closed state of the migration door in this invention. Figure 2 ; Figure 4 This is a schematic diagram of the structure of the migration door in the open state in this invention; Figure 5 This is a top view of the sliding door in the open state in this invention; Figure 6 for Figure 5 A cross-sectional view along AA; Figure 7 for Figure 5A cross-sectional view along BB; Figure 8 for Figure 7 A magnified view of a portion of the image; Figure 9 This is a schematic diagram of the vacuum regulation module in this invention; Figure 10 This is a schematic diagram of the water tank module in this invention; Figure 11 This is a connection diagram of the central controller of the present invention; Figure 12 This is a schematic diagram of the quick-connect mechanism in the unlocked state of the present invention; Figure 13 This is a cross-sectional schematic diagram of the quick-connect mechanism in the present invention in the unlocked state; Figure 14 This is a schematic diagram of the quick-connect mechanism in the locked state of the present invention.

[0036] In the attached diagram, 1 is the vacuum regulating module, 2 is the water tank module, 3 is the sample test chamber module, 4 is the electronic balance chamber module, 5 is the central controller, 6 is the sample transfer device, 7 is the transfer port, 8 is the transfer door, 9 is the drive mechanism, 10 is the vertical rod, 11 is the horizontal rod, 12 is the connecting slide rail, 13 is the quick connection mechanism, 14 is the multi-stage vacuum pump group, 15 is the vacuum buffer tank, 16 is the vacuum degree sensor, 17 is the vacuum solenoid valve group, 18 is the vacuum pipeline, 21 is the distilled water storage tank, 22 is the ultrasonic nebulizer, 23 is the humidity generator, 24 is the dehumidification device, 25 is the circulating water pump, 26 is the water level sensor, 27 is the water quality monitoring unit, 28 is the automatic water replenishment system, 29 is the humidity delivery pipeline, 31 is the test chamber shell, 32 is the sealed test chamber, 33 is the sample support platform, 34 is the control console, 35 is the test chamber door, 331 is the support rod, 332 is the placement rod, 333 is the support frame, 334 is the support rod. 41. Spacer bar; 42. Balance chamber housing; 43. Sealed balance chamber cavity; 44. High-precision electronic balance; 45. Balance chamber door; 46. Constant temperature and humidity system; 47. Balance control housing; 68. Robotic arm; 69. Linear guide slider; 60. Linear slide rail; 61. Slot; 62. Square slot; 63. Snap-fit ​​component; 64. Notch; 95. Cylinder seat; 96. Piston rod; 97. Connecting block; 98. Drive slider; 99. Drive slide rail; 100. Base; 111. Arc block; 12. Outer guide ring; 132. Inner guide ring; 133. Lever; 14. Arc hole; 15. Inner guide groove; 16. Outer guide groove; 17. Lever. Detailed Implementation

[0037] The present invention will be further described below: Please see Figure 1-14 .

[0038] Example 1: Overall Structure of the Device This embodiment provides a device for measuring the total migration of food contact materials, including a vacuum conditioning module 1, a water tank module 2, a sample testing chamber module 3, an electronic balance chamber module 4, a central controller 5, and a sample migration device 6.

[0039] The sample testing chamber module 3 serves as the main working area for vacuum drying, humidity control, and environmental equilibration of samples. The vacuum control module 1 is connected to the lower left side wall of the sample testing chamber module 3, the water tank module 2 is located at the top of the sample testing chamber module 3, and the electronic balance chamber module 4 is connected to the right side wall of the sample testing chamber module 3. This arrangement allows the vacuum pipeline 18 and the humidity delivery pipeline 29 to connect to the sealed testing chamber 32 via a shorter path, while also enabling the sample to be directly transferred horizontally from the sealed testing chamber 32 to the sealed balance chamber 42.

[0040] The sample test chamber module 3 includes a test chamber shell 31, a sealed test chamber 32, a sample support platform 33, a control console 34, and a test chamber door 35. The test chamber shell 31 is generally square, and the sealed test chamber 32 is located on the upper part of the test chamber shell 31. Its front end forms an opening for inserting and removing samples, and the test chamber door 35 is located at this opening.

[0041] A heat-resistant sealing ring is installed between the test chamber door 35 and the sealed test chamber 32, and the sealing ring can be tightened by a locking mechanism. The walls of the sealed test chamber 32 can be insulated to reduce the influence of the external environment on the internal temperature. Temperature, humidity, and pressure sensors are installed inside the sealed test chamber 32. The control console 34 controls the heating components, cooling components, vacuum regulation module 1, water tank module 2, and pressure relief valve based on the detection results of each sensor to regulate the temperature, pressure, and relative humidity inside the sealed test chamber 32.

[0042] The electronic balance chamber module 4 includes a balance chamber housing 41, a sealed balance chamber cavity 42, a high-precision electronic balance 43, a balance chamber cavity door 44, and a constant temperature and humidity system 45. The sealed balance chamber cavity 42 is located on the upper part of the balance chamber housing 41, and the balance chamber cavity door 44 is installed at its front opening. The high-precision electronic balance 43 is located at the bottom of the inner cavity of the sealed balance chamber cavity 42.

[0043] The constant temperature and humidity system 45 includes a temperature regulating component, a humidity regulating component, a circulating fan, and temperature and humidity sensors. The central controller 5 controls the constant temperature and humidity system 45 based on data feedback from the temperature and humidity sensors, maintaining the sealed balance chamber 42 at 25℃±0.5℃ and a relative humidity of 50%±2%. The airflow direction of the circulating fan avoids the weighing area of ​​the high-precision electronic balance 43, or the circulating fan speed is reduced during the weighing stage to minimize the impact of airflow on the weighing results.

[0044] A migration port 7 is provided between the sealed test chamber 32 and the sealed balance chamber 42. The migration port 7 is opened during sample migration and closed by the migration door 8 during sample processing or weighing, so that the two chambers can maintain their respective temperature, humidity and pressure conditions.

[0045] Example 2: Sample support stage The sample support platform 33 includes a support rod 331, a placement rod 332, a support frame 333, and a spacer rod 334.

[0046] Four support rods 331 are fixed vertically to the front and rear positions of the left and right side walls of the sealed test chamber 32, respectively. Multiple placement rods 332 are equally spaced vertically on the outer wall of each support rod 331. Multiple placement rods 332 at the same height jointly support a bearing frame 333, thereby forming a multi-layer sample placement structure.

[0047] The support frame 333 is rectangular, with multiple spacer bars 334 evenly spaced between the opposing inner walls of the support frame 333. Samples can be placed directly on the spacer bars 334, or first placed in a sample cup and then placed on the spacer bars 334. The gaps between adjacent spacer bars 334 form airflow channels, allowing for sufficient gas exchange around the samples during vacuum drying or constant humidity conditioning.

[0048] The support frame 333 is detachably placed on the placement rod 332 so that the distance between adjacent support frames 333 can be adjusted according to the sample size, and the support frame 333 can also be cleaned and maintained.

[0049] Example 3: Sample Migration and Inter-compartment Isolation Structure The sample transfer device 6 includes a roller linear guide system and a robotic arm 61. The roller linear guide system includes a linear guide slider 62 and a linear slide rail 63. The base of the robotic arm 61 is fixed to the linear guide slider 62, and the linear guide slider 62 can reciprocate along the linear slide rail 63.

[0050] One end of the linear slide rail 63 is fixed to the top of the sealed test chamber 32, and the other end extends through the migration port 7 to the top of the sealed balance chamber 42 and is fixedly connected thereto. The robotic arm 61 moves along the linear slide rail 63 via the linear guide slider 62, thereby switching positions between the sealed test chamber 32 and the sealed balance chamber 42.

[0051] The linear guide rail 63 has a square cross-section, with semi-circular grooves 64 on the lower part of its two side walls. The top of the linear guide rail slider 62 has a square groove 65, which fits over the linear guide rail 63. The inner walls of both sides of the square groove 65 are fitted with engaging parts 66 that match the grooves 64. The engaging parts 66 can be rollers or low-friction sliders; after entering the grooves 64, they restrict the linear guide rail slider 62 from wobbling in the non-moving direction or disengaging from the linear guide rail 63.

[0052] A migration door 8 is provided on the side of the migration port 7 near the sealed balance chamber 42. The migration door 8 is driven by a drive mechanism 9 and moves vertically. The drive mechanism 9 includes a cylinder seat 91, a piston rod 92, a connecting block 93, a drive slider 94, and a drive slide rail 95.

[0053] A hollow balance control housing 46 is provided at the bottom of the balance compartment housing 41, and a cylinder seat 91 is fixed to the left side of the inner cavity of the balance control housing 46. The bottom end of the piston rod 92 cooperates with the cylinder seat 91, and the top end of the piston rod 92 passes through the sealing guide hole at the bottom of the sealed balance compartment cavity 42 and connects to the middle of the bottom end of the connecting block 93. The connecting block 93 is fixedly connected to the sliding door 8, and the drive sliders 94 at both ends of the connecting block 93 cooperate with the drive slide rails 95 arranged in the vertical direction. Through the guiding action of the drive sliders 94 and the drive slide rails 95, the sliding door 8 can be prevented from tilting during the lifting and lowering process.

[0054] A notch 67 is provided on the linear slide rail 63 corresponding to the position of the sliding door 8. The dimension of the notch 67 along the length of the linear slide rail 63 is the same as the thickness of the sliding door 8. Vertical rods 10 are connected to the top two sides of the sliding door 8, and the top ends of the two vertical rods 10 are connected by a horizontal rod 11. The horizontal rod 11 passes through the horizontal rod hole at the top of the sealed balance chamber 42, and a connecting slide rail 12 is provided at its bottom. The length of the connecting slide rail 12 is equal to the thickness of the sliding door 8, and the cross-sectional shape of the connecting slide rail 12 is the same as that of the linear slide rail 63.

[0055] When sample migration is required, the central controller 5 first adjusts the sealed test chamber 32 to pressure, temperature, and humidity conditions close to those of the sealed balance chamber 42. Once the conditions reach the preset range, the central controller 5 controls the drive mechanism 9 to operate, and the piston rod 92 drives the connecting block 93 and the migration door 8 to move downwards along the drive slide rail 95. The migration door 8 leaves the migration opening 7, and the vertical rod 10 and horizontal rod 11 move downwards simultaneously, causing the connecting slide rail 12 to enter the notch 67 of the linear slide rail 63. The two ends of the connecting slide rail 12 are aligned with the linear slide rails 63 on both sides of the notch 67, forming a continuous track.

[0056] Subsequently, the robotic arm 61 grasps the sample cup located on the sample support stage 33, and the linear guide slider 62 passes through the migration port 7 along the continuous track and enters the sealed balance chamber 42. The robotic arm 61 places the sample cup on the weighing pan of the high-precision electronic balance 43 and exits the weighing area. After the weighing data stabilizes, the central controller 5 reads and stores the weighing data. After weighing is completed, the robotic arm 61 grasps the sample cup again and returns it to its original position in the sealed test chamber 32.

[0057] After the robotic arm 61 leaves the migration port 7, the drive mechanism 9 drives the migration door 8 to move upward. The connecting slide rail 12 leaves the notch 67, and the migration door 8 enters the closed position of the migration port 7, pressing the seals around the migration port 7, thereby restoring the isolation state between the sealed test chamber 32 and the sealed balance chamber 42.

[0058] Example 4: Vacuum and Humidity Control Structure The vacuum regulation module 1 includes a multi-stage vacuum pump group 14, a vacuum buffer tank 15, a vacuum degree sensor 16, a vacuum solenoid valve group 17, and a vacuum pipeline 18.

[0059] The multi-stage vacuum pump assembly 14 includes a coarse vacuum pump and a fine vacuum pump connected in sequence. One end of the vacuum buffer tank 15 is connected to the multi-stage vacuum pump assembly 14 via a vacuum pipeline 18, and the other end is connected to the vacuum interface of the sealing test chamber 32 via a vacuum solenoid valve assembly 17. The volume of the vacuum buffer tank 15 is not less than three times the volume of the sealing test chamber 32, and is used to reduce pressure fluctuations caused by the start-up and shutdown of the vacuum pump and valve switching.

[0060] The vacuum sensor 16 is a capacitive thin-film vacuum gauge with a measurement accuracy of not less than ±0.1 kPa. It can be installed in the vacuum pipeline 18 and / or the sealed test chamber 32 to detect the vacuum level in the sealed test chamber 32 in real time. Based on the detection value of the vacuum sensor 16, the central controller 5 controls the operation of the coarse vacuum pump, the fine vacuum pump, and the vacuum solenoid valve group 17 to gradually adjust the pressure in the sealed test chamber 32 from atmospheric pressure to approximately 1.3 kPa and maintain it within the preset pressure range.

[0061] During vacuuming, the central controller 5 first controls the coarse vacuum pump to quickly reduce the pressure inside the sealed test chamber 32. Once the pressure drops to a preset switching value, the fine vacuum pump is started, and the opening and closing status of the vacuum solenoid valve assembly 17 is adjusted according to the feedback signal from the vacuum sensor 16. The vacuum buffer tank 15 is used to buffer pressure fluctuations caused by the start-up and shutdown of the vacuum pump and valve switching. After the vacuum treatment is completed, the central controller 5 closes the vacuum solenoid valve assembly 17 and controls the air inlet valve to introduce clean air into the sealed test chamber 32 at a preset speed, allowing the sealed test chamber 32 to gradually return to normal pressure.

[0062] The water tank module 2 includes a distilled water storage tank 21, an ultrasonic atomizer 22, a humidity generator 23, a dehumidification device 24, a circulating water pump 25, a water level sensor 26, a water quality monitoring unit 27, an automatic water replenishment system 28, and a humidity delivery pipeline 29.

[0063] The ultrasonic atomizer 22 is installed inside the distilled water storage tank 21, or connected to the distilled water storage tank 21 via a water supply pipeline. The ultrasonic atomizer 22 uses high-frequency ultrasonic oscillation to atomize distilled water into atomized particles with a particle size of no more than 5 μm. The humidity generator 23 mixes the atomized particles with clean gas and delivers the mixture to the sealed test chamber 32 via the humidity delivery pipeline 29.

[0064] The circulating water pump 25 is used to circulate the distilled water in the distilled water storage tank 21 to reduce local water quality or temperature differences. A flow regulating valve and a check valve can be installed on the humidity delivery pipeline 29. The flow regulating valve is used to regulate the amount of water vapor delivered, and the check valve is used to prevent gas in the sealed test chamber 32 from flowing back into the water tank module 2.

[0065] The dehumidification device 24 is connected to the sealed test chamber 32 and includes a semiconductor refrigeration dehumidification component and a molecular sieve adsorption dehumidification component. When the relative humidity inside the sealed test chamber 32 is higher than the preset upper limit, the central controller 5 controls the operation of the semiconductor refrigeration dehumidification component, causing water vapor in the airflow to condense on the low-temperature surface. When further reduction of humidity is required, the airflow is controlled to pass through the molecular sieve adsorption dehumidification component to adsorb the remaining moisture in the airflow. When the relative humidity is lower than the preset lower limit, the central controller 5 shuts off the dehumidification device 24 and activates the ultrasonic atomizer 22 and the humidity generator 23. Through bidirectional adjustment of humidification and dehumidification, the relative humidity inside the sealed test chamber 32 is maintained within the preset range.

[0066] A water level sensor 26 is installed inside the distilled water storage tank 21 to detect the distilled water level. The water quality monitoring unit 27 includes a conductivity detection component and a total organic carbon (TOC) detection component to detect the conductivity and TOC content of the distilled water. When the water level is below the preset level, the central controller 5 controls the opening of the water supply solenoid valve on the water supply pipeline, allowing external pure water to supply water to the distilled water storage tank 21; when the water level reaches the preset upper limit, the central controller 5 closes the water supply solenoid valve. When the water quality detection result exceeds the preset range, the central controller 5 issues an alarm signal through the alarm unit and can pause the humidity generation program to prevent unsuitable water sources from affecting the test results.

[0067] Example 5: Quick-connect structure for water tank module The top of the test chamber shell 31 is connected to the bottom of the water tank module 2 via a quick-connect mechanism 13. The quick-connect mechanism 13 includes two identical connecting units, which are respectively located at the bottom of the two side walls of the water tank module 2 and the top of the two side walls of the test chamber shell 31, and are arranged symmetrically about the midpoint of the connection.

[0068] Each connecting unit includes a base 131, an arc block 132, an outer guide ring 133, an inner guide ring 134, and a lever 135. The base 131 is square, with an arc hole 136 in its center that matches the arc block 132. The inner guide ring 134 and the outer guide ring 133 are connected sequentially to the sidewalls of the arc block 132, and the inner walls of both the inner guide ring 134 and the outer guide ring 133 are flush with the inner wall of the arc block 132.

[0069] The thickness of the inner guide ring 134 is less than the thickness of the arc block 132, and the thickness of the outer guide ring 133 is greater than the thickness of the inner guide ring 134 but less than the thickness of the arc block 132. An inner guide groove 137 and an outer guide groove 138 are respectively provided within the base 131. The inner guide ring 134 can rotate within the inner guide groove 137, and the outer guide ring 133 can rotate within the outer guide groove 138. The outer guide groove 138 communicates with the arc hole 136 via the inner guide groove 137.

[0070] A slot 139 is provided on the top of the base 131, and the bottom end of the lever 135 passes through the slot 139 and connects to the outer guide ring 133. When installing the water tank module 2, first align the connecting unit at the bottom of the water tank module 2 with the connecting unit at the top of the test chamber shell 31, so that the corresponding arc block 132 enters the arc hole 136; then move the lever 135 to drive the outer guide ring 133, inner guide ring 134 and arc block 132 to rotate, so that the two connecting units engage with each other. When disassembling, move the lever 135 in the opposite direction to disengage the arc block 132 from the engaged position, and the water tank module 2 can be removed from the top of the test chamber shell 31.

[0071] The fluid interface between the water tank module 2 and the test chamber shell 31 can be a quick connector with a self-sealing valve. When the water tank module 2 is installed in place, the quick connector automatically connects; when the water tank module 2 is removed, the self-sealing valve closes to prevent distilled water leakage or external impurities from entering the pipeline.

[0072] Example 6: Central Controller and Automatic Control Process The central controller 5 is electrically or communicatively connected to the vacuum regulation module 1, water tank module 2, sample test chamber module 3, electronic balance chamber module 4, and sample transfer device 6, respectively.

[0073] The central controller 5 includes a control processing unit, a data acquisition unit, a data storage unit, a communication unit, a human-machine interaction unit, and an alarm unit. The data acquisition unit collects data from the vacuum sensor 16, the water level sensor 26, the water quality monitoring unit 27, the temperature sensor, humidity sensor, and pressure sensor in the sealed test chamber 32, the temperature and humidity sensor in the constant temperature and humidity system 45, and the output data from the high-precision electronic balance 43.

[0074] The control and processing unit sends control commands to the multi-stage vacuum pump group 14, vacuum solenoid valve group 17, ultrasonic atomizer 22, humidity generator 23, dehumidifier 24, automatic water replenishment system 28, constant temperature and humidity system 45, drive mechanism 9 and robotic arm 61 according to the preset test program and sensor feedback data.

[0075] The human-machine interface unit can be a touch screen or operating software connected to a host computer. Test personnel input information such as sample number, sample type, sample quantity, sample size, actual contact area, test mode, processing temperature, target humidity, target pressure, processing time, and weighing interval through the human-machine interface unit. The data storage unit stores sample information, environmental parameters during processing, weighing data for each weighing, equipment operating status, and alarm information.

[0076] The alarm unit is used to issue audible and visual alarms when the test chamber sealing is abnormal, the vacuum level fails to reach the set value, the temperature and humidity exceed the limits, the water level is abnormal, the water quality is abnormal, the transfer door is not in place, the robotic arm fails to grasp, or the electronic balance communication is abnormal. The alarm type and occurrence time are recorded in the data storage unit. For anomalies that affect the validity of the test, the central controller 5 pauses the current program, putting the vacuum pump, robotic arm, and drive mechanism 9 into a preset safety state.

[0077] Example 7: Moisture Sensitivity Test of Vacuum Drying Method This embodiment uses the vacuum drying method to determine whether a food contact material sample is a moisture-sensitive sample.

[0078] First, prepare the test samples according to the relevant requirements for migration testing of food contact materials. For the full immersion method or the filling method, the contact area of ​​the sample should not be less than 1 dm²; when using the test cell method, the actual area of ​​the sample in contact with the food simulant should be used as the contact area; when using the bagged method, the contact area of ​​the sample should not be less than 2 dm². Two or three parallel samples can be set up for each group.

[0079] The tester opens the test chamber door 35, places each sample into a sample cup, and then places the sample cup on the sample support stage 33. After closing the test chamber door 35, the tester inputs the sample number, size, and contact area through the human-machine interface unit and selects the vacuum drying method program.

[0080] Before vacuum drying begins, the sealed test chamber 32 is adjusted to a constant temperature and humidity condition similar to or the same as that of the sealed balance chamber 42. After the environment stabilizes, the robotic arm 61 sequentially delivers each sample cup to the high-precision electronic balance 43 for initial weighing. The central controller 5 records the mass of each sample before drying and returns the sample cup to the sample support stage 33.

[0081] After the initial weighing is completed, the central controller 5 controls the migration door 8 to close and adjusts the temperature of the sealed test chamber 32 to 60℃±5℃. The vacuum regulation module 1 adjusts the pressure inside the sealed test chamber 32 to approximately 1.3kPa and maintains it for 60min±10min.

[0082] After vacuum treatment, the central controller 5 controls the sealed test chamber 32 to slowly return to normal pressure and cool for 60 min ± 10 min. Then, the sealed test chamber 32 is adjusted to 25℃ and 50% relative humidity to closely match the environmental conditions of the sealed balance chamber 42. Once the temperature, humidity, and pressure are all within acceptable ranges, the transfer door 8 is opened, and the robotic arm 61 sequentially transfers each sample cup to the high-precision electronic balance 43 for drying and weighing.

[0083] The central controller 5 calculates the change in mass per unit area based on the mass of each sample before and after drying and the actual contact area. The change in mass per unit area can be calculated using the following formula: ; In the formula: This represents the change in mass per unit area, expressed in mg / dm². The mass of the sample before vacuum drying is expressed in mg. The mass of the sample after vacuum drying is expressed in mg. S represents the actual contact area of ​​the sample, in dm².

[0084] When multiple parallel samples are set, the arithmetic mean of the change in mass per unit area of ​​each parallel sample can be used as the judgment value. When the judgment value is not greater than 2 mg / dm², the central controller 5 determines the sample as a non-moisture-sensitive sample, and no special moisture content adjustment is required before or after the migration test; when the judgment value is greater than 2 mg / dm², the sample is determined as a moisture-sensitive sample, and the system automatically enters or prompts the user to enter the moisture content adjustment program.

[0085] Example 8: Moisture content adjustment in vacuum drying method For the sample determined to be moisture-sensitive in Example 7, the central controller 5 executes the moisture content adjustment program before the migration test.

[0086] The central controller 5 adjusts the sealed test chamber 32 to 60℃±5℃ and evacuates it to approximately 1.3kPa, maintaining this state for 24h±2h. After processing, the sealed test chamber 32 is restored to normal pressure and cooled, then adjusted to 25℃ and 50% relative humidity. Once the environment stabilizes, the robotic arm 61 delivers each sample cup to the high-precision electronic balance 43 for weighing.

[0087] After weighing, the robotic arm 61 returns the sample cup to the sealed test chamber 32. The central controller 5 repeats the vacuum drying, environmental equilibration, and weighing steps according to a preset cycle until the difference in unit area mass between two consecutive weighings of the same sample is no greater than 2 mg / dm². The mass obtained from the last weighing of each sample is used as the initial mass before the migration test.

[0088] To restore the appropriate moisture content of the vacuum-dried sample, a further moisture content adjustment procedure can be performed. The central controller 5 controls the water tank module 2 to maintain a constant humidity environment of 80% in the sealed test chamber 32. After a preset time, the sealed test chamber 32 is adjusted to 25°C and 50% relative humidity, and the robotic arm 61 delivers the sample cup to the high-precision electronic balance 43 for weighing.

[0089] The central controller 5 compares the mass loss during vacuum drying with the mass increase after adjusting the re-moisture content. The re-moisture content adjustment program ends when the mass regained by the sample reaches 80%–120% of the mass lost during vacuum drying. Afterward, the test personnel can remove the sample for food simulant migration testing.

[0090] After the migration test, the sample is placed back into the corresponding sample cup and sample support stage 33. The central controller 5 adjusts the sealed test chamber 32 to 60℃±5℃ and approximately 1.3kPa again, and maintains this temperature for 24h±2h. The environmental equilibration and automatic weighing process is then repeated until the difference in unit area mass between two consecutive weighings is no greater than 2mg / dm². The mass obtained from the last weighing of each sample is taken as the final mass of the sample.

[0091] Example 9: Moisture Sensitivity Test by Constant Humidity Method This embodiment uses the constant humidity method to determine whether the sample is a moisture-sensitive sample.

[0092] Place two or three prepared parallel samples into sample cups and then onto the sample support stage 33. After closing the test chamber door 35, input the sample dimensions, actual contact area, and sample number through the human-computer interaction unit, and select the constant humidity method program.

[0093] The central controller 5 first maintains the sealed test chamber 32 at an environment of 25°C and 50% relative humidity. After the environment stabilizes, the robotic arm 61 sequentially sends the sample cups to the high-precision electronic balance 43 for initial weighing and then returns the sample cups to the sealed test chamber 32.

[0094] Subsequently, the central controller 5 controls the water tank module 2 to adjust the relative humidity of the sealed test chamber 32 to 80% and maintain it for 24h±4h. After the treatment is completed, the sealed test chamber 32 is readjusted to 25℃ and 50% relative humidity. After the environment stabilizes, the robotic arm 61 delivers each sample cup to the high-precision electronic balance 43 for weighing.

[0095] The central controller 5 calculates the change in mass per unit area of ​​the sample before and after constant humidity treatment. When the arithmetic mean of the change in mass per unit area of ​​parallel samples is not greater than 2 mg / dm², the sample is determined to be a non-moisture-sensitive sample; when it is greater than 2 mg / dm², the sample is determined to be a moisture-sensitive sample and enters the constant humidity method moisture content adjustment program.

[0096] Example 10: Moisture Content Adjustment by Constant Humidity Method For samples whose moisture content is regulated using a constant humidity method, the central controller 5 controls the sealed test chamber 32 to maintain a constant humidity environment of 50% relative humidity, and weighs the samples according to a preset cycle. In one embodiment, the weighing cycle is 24 hours.

[0097] Before each weighing, the central controller 5 confirms that the temperature and humidity difference between the sealed test chamber 32 and the sealed balance chamber 42 is within a preset range, and then controls the transfer door 8 to open. The robotic arm 61 sequentially delivers the sample cup to the high-precision electronic balance 43 for weighing, and returns it to the sealed test chamber 32 after weighing.

[0098] The central controller 5 compares the weighing data of two consecutive weighings of the same sample. When the difference in mass per unit area between two consecutive weighings is no greater than 2 mg / dm², the sample mass is considered to have reached a stable state, and the last weighing result is used as the initial mass before the migration test.

[0099] After the migration test is completed, the sample is placed back into the corresponding sample cup, and the central controller 5 controls the sealed test chamber 32 to maintain a relative humidity of 50% again, and the weighing is repeated according to the preset cycle. When the difference in unit area mass between two consecutive weighings is not greater than 2 mg / dm², the result of the last weighing is taken as the final mass after the migration test.

[0100] Example 11: Total Migration Calculation and Data Output After obtaining the initial and final mass of the sample, the central controller 5 automatically calculates the total migration amount based on the actual contact area of ​​the sample. For cases where the total migration amount is evaluated based on the increase in sample mass after the migration test, it can be calculated using the following formula: ; In the formula: Total migration amount, in mg / dm²; The initial mass of the sample after moisture content adjustment before the migration test is expressed in mg. The final mass of the sample after the migration test and moisture content adjustment is expressed in mg. S represents the area of ​​the sample actually in contact with the food simulant, expressed in dm².

[0101] The actual calculation method can be set according to the food simulant used, the migration test method, and the applicable standards. For tests that require subtracting blank test results or making other corrections, the central controller 5 can call blank values ​​and correction parameters according to the preset calculation program to perform the calculation.

[0102] The test results generated by the central controller 5 include at least the sample number, sample name, sample size, actual contact area, selected test mode, moisture sensitivity judgment result, weighing data for each test, initial mass, final mass, total migration, temperature change curve, humidity change curve, pressure change curve, test start and end time, and equipment alarm records.

[0103] The communication unit can connect to the laboratory information management system via wired or wireless means to output test data and test reports. The data storage unit retains original sensor data, original weighing data, and control command records for querying and tracing the test process.

[0104] In the above embodiments, the listed temperature, humidity, pressure, processing time, and quality stability judgment values ​​can be adjusted according to the corresponding food contact material testing standards and sample characteristics. The robotic arm 61 can also be replaced by a multi-axis actuator with the same sample gripping and migration functions; the drive mechanism 9 can be a cylinder, electric push rod, or lead screw drive mechanism. Any implementation that achieves isolation, track connection, and automatic sample migration between the sealed test chamber 32 and the sealed balance chamber 42 can be considered an equivalent embodiment of the present invention.

[0105] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A device for measuring the total migration of food contact materials, characterized in that, It includes a vacuum conditioning module (1), a water tank module (2), a sample test chamber module (3), an electronic balance chamber module (4), a central controller (5), and a sample transfer device (6). The sample test chamber module (3) includes a test chamber shell (31), a sealed test chamber (32), a sample support platform (33), a control console (34), and a test chamber door (35). The test chamber shell (31) has a square structure, and the sealed test chamber (32) is square on the upper part of its outer wall. The sample support platform (33) for placing samples is provided in the sealed test chamber (32). The test chamber door (35) is provided at the front opening of the sealed test chamber (32). The control console (34) can adjust the temperature, pressure, and humidity inside the sealed test chamber (32). The vacuum adjustment module (1) is connected to the lower left side wall of the sample test chamber module (3) and is used to perform vacuum treatment on the sample test chamber module (3). The water tank module (2) is located on top of the sample test chamber module (3) and is used to store distilled water and supply water vapor to the sample test chamber module (3) to regulate the humidity inside the chamber. The electronic balance chamber module (4) is connected to the right side wall of the sample test chamber module (3) and is used to weigh the sample in a constant temperature and humidity environment. The samples in the sample test chamber module (3) can be transferred to the electronic balance chamber module (4) through the sample transfer device (6).

2. The device for measuring the total migration of food contact materials according to claim 1, characterized in that, The electronic balance chamber module (4) includes a balance chamber shell (41), a sealed balance chamber cavity (42), a high-precision electronic balance (43), a balance chamber cavity door (44), and a constant temperature and humidity system (45). The sealed balance chamber shell (41) has a square structure, and the sealed balance chamber cavity (42) is square on the upper part of its front wall. The front opening of the sealed balance chamber cavity (42) is provided with the balance chamber cavity door (44). The high-precision electronic balance (43) is disposed in the sealed balance chamber. The constant temperature and humidity system (45) is set inside the sealed balance chamber (42) at the bottom of the inner cavity of the balance chamber (42) to maintain the environment inside the balance chamber at 25°C±0.5°C and relative humidity at 50%±2%. A migration port (7) is provided between the sealed balance chamber (42) and the sealed test chamber (32). The sample migration device (6) migrates the sample from the sealed test chamber (32) to the sealed balance chamber (42) through the migration port (7).

3. The device for measuring the total migration of food contact materials according to claim 2, characterized in that, The sample transfer device (6) includes a roller linear guide system and a robotic arm (61). The base of the robotic arm (61) is fixed on the linear guide slider (62) of the roller linear guide system. The linear guide slider (62) slides in cooperation with the linear slide rail (63) of the roller linear guide system. One end of the slide rail is fixed to the top of the sealed test chamber (32), and the other end passes through the top of the transfer port (7) and is fixedly connected to the top of the sealed balance chamber (42). The robotic arm (61) can move from the sealed test chamber (32) to the sealed balance chamber (42) through the roller linear guide system.

4. The device for measuring the total migration of food contact materials according to claim 3, characterized in that, The right side of the migration port (7) is provided with a migration door (8) that can close it. The migration door (8) is located inside the sealed balance chamber (42). The migration door (8) is driven to move vertically by a drive mechanism (9). The drive mechanism (9) includes a cylinder seat (91), a piston rod (92), a connecting block (93), a drive slider (94), and a drive slide rail (95). The bottom of the balance chamber housing (41) is provided with a balance control housing (46) with a hollow square structure and an open front end. The cylinder seat (91) is fixed to the left side of the inner cavity of the balance control housing (46). The bottom end of the piston rod (92) can... The piston rod (92) can move vertically along the inner cavity of the cylinder seat (91). The top end of the piston rod (92) passes through the bottom of the sealed balance chamber (42) and is connected to the middle of the bottom end of the connecting block (93). The inner wall of the connecting block (93) is fixedly connected to the middle of the outer wall of the migration door (8). The length of the connecting block (93) is greater than the width of the migration door (8). The inner walls at both ends of the connecting block (93) are provided with driving sliders (94). The left side wall of the sealed balance chamber (42) is provided with driving slide rails (95) arranged vertically on both sides. The driving sliders (94) and the driving slide rails (95) cooperate to slide.

5. The device for measuring the total migration of food contact materials according to claim 4, characterized in that, The linear slide rail (63) has a square cross-section, and semi-circular slots (64) are provided on the lower side walls of its two sides; the linear guide slider (62) has a square structure, and a square groove (65) for inserting the linear slide rail (63) is provided on its top. The inner walls of the square groove (65) are provided with snap-fit ​​pieces (66) that match the shape of the slot (64). The linear slide rail (63) is located at the sliding door (8) with a notch (67) of the same thickness as the sliding door (8); the top two sides of the sliding door (8) A vertical rod (10) is connected, and a horizontal rod (11) is connected between the top ends of the vertical rod (10). The top of the sealed balance chamber (42) is provided with a horizontal rod hole for the horizontal rod (11) to pass through. The bottom of the horizontal rod (11) is provided with a connecting slide rail (12). The length of the connecting slide rail (12) is equal to the thickness of the sliding door (8). The cross-sectional shape of the connecting slide rail (12) is the same as the cross-sectional shape of the straight slide rail (63). The length of the vertical rod (10) is greater than the height of the sliding door (8).

6. The device for measuring the total migration of food contact materials according to claim 1, characterized in that, The sample support platform (33) includes a support rod (331), a placement rod (332), a support frame (333), and spacer rods (334). Four rods (331) are fixed vertically to the front and rear sides of the left and right walls of the sealed test chamber (32). Several placement rods (332) are equally spaced vertically on the outer wall of the support rod (331). The support frame (333) is a square frame structure on the placement rod (332). Several spacer rods (334) are equally spaced between the inner walls of the support frame (333). The sample is placed on the top of the spacer rod (334).

7. The device for measuring the total migration of food contact materials according to claim 1, characterized in that, The top of the outer wall of the test chamber shell (31) is connected to the bottom of the outer wall of the water tank module (2) by a quick connection mechanism (13). The quick connection mechanism (13) includes two identical connection units, which are respectively fixed to the bottom of the two side walls of the water tank module (2) and the top of the two side walls of the test chamber shell (31). The two connection units are symmetrically arranged about the midpoint of the connection. The connection unit includes a base (131), an arc block (132), an outer guide ring (133), an inner guide ring (134), and a lever (135). The base (131) has a square structure, and its middle part is provided with an arc hole (136) that matches the shape of the arc block (132). The inner guide ring (134) is connected to the side wall of the arc block (132). The inner wall of the inner guide ring (134) is flush with the inner wall of the arc block (132). The thickness of the inner guide ring (134) is less than the thickness of the arc block (132). The inner guide ring (134) is connected to the outer guide ring (133) on its sidewall. The inner wall of the outer guide ring (133) is flush with the inner wall of the inner guide ring (134). The thickness of the outer guide ring (133) is less than the thickness of the arc block (132), and the thickness of the outer guide ring (133) is greater than the thickness of the inner guide ring (134). The inner wall of the base (131) is provided with an inner guide groove (137) for the rotation of the inner guide ring (134) and a groove for the rotation of the inner guide ring (134). The outer guide groove (138) rotates on the outer guide ring (133). The outer guide groove (138) is connected to the arc hole (136) through the inner guide groove (137). The top of the base (131) is provided with a groove (139) for rotating the lever (135). The bottom of the groove (139) is connected to the outer guide groove (138). The bottom end of the lever (135) passes through the groove (139) and is connected to the side wall of the outer guide ring (133).

8. The device for measuring the total migration of food contact materials according to claim 6, characterized in that, The vacuum regulation module (1) includes a multi-stage vacuum pump group (14), a vacuum buffer tank (15), a vacuum sensor (16), a vacuum solenoid valve group (17), and a vacuum pipeline (18). The multi-stage vacuum pump group (14) includes a coarse vacuum pump and a fine vacuum pump connected in sequence. One end of the vacuum buffer tank (15) is connected to the multi-stage vacuum pump group (14) via the vacuum pipeline (18), and the other end is connected to the vacuum interface of the sealed test chamber (32) via the vacuum solenoid valve group (17). The vacuum sensor (16) is installed in the vacuum pipeline (18) and / or the sealed test chamber (32) to detect the vacuum level in the sealed test chamber (32); the volume of the vacuum buffer tank (15) is not less than three times the volume of the sealed test chamber (32); the multi-stage vacuum pump group (14) is used to adjust the pressure in the sealed test chamber (32) from atmospheric pressure to 1.3 kPa; the vacuum sensor (16) is a capacitive thin-film vacuum gauge with a measurement accuracy of not less than ±0.1 kPa.

9. The device for measuring the total migration of food contact materials according to claim 8, characterized in that, The water tank module (2) includes a distilled water storage tank (21), an ultrasonic atomizer (22), a humidity generator (23), a dehumidifier (24), a circulating water pump (25), a water level sensor (26), a water quality monitoring unit (27), an automatic water replenishment system (28), and a humidity delivery pipeline (29). The ultrasonic atomizer (22) is located inside or connected to the distilled water storage tank (21). The humidity generator (23) is connected to the humidity interface of the sealed test chamber (32) via the humidity delivery pipeline (29) to deliver humidified gas (after atomization and vaporization or gas-liquid separation) to the sealed test chamber (32). The dehumidifier (24) is connected to the sealed test chamber (32) to reduce the humidity of the sealed test chamber (32). The humidity inside; the ultrasonic atomizer (22) adopts high-frequency ultrasonic oscillation mode, and the atomized particles generated by it have a particle size of no more than 5μm; the dehumidification device (24) includes a semiconductor refrigeration dehumidification component and a molecular sieve adsorption dehumidification component; the water quality monitoring unit (27) is used to detect the conductivity and total organic carbon content of distilled water, and the water level sensor (26) is used to detect the liquid level in the distilled water storage tank (21); the automatic water replenishment system (28) is connected to an external pure water source through a water replenishment pipeline, and a water replenishment solenoid valve is installed on the water replenishment pipeline; when the water level sensor (26) detects that the liquid level in the distilled water storage tank (21) is lower than the preset liquid level, the central controller (5) controls the water replenishment solenoid valve to open, so as to automatically replenish distilled water to the distilled water storage tank (21).

10. The device for measuring the total migration of food contact materials according to claim 9, characterized in that, The central controller (5) is electrically or communicatively connected to the vacuum regulation module (1), water tank module (2), sample test chamber module (3), electronic balance chamber module (4), and sample transfer device (6), respectively. The central controller (5) is used to receive sensor detection signals from each module and send control commands to each module according to the preset test program. The central controller (5) is connected to the vacuum sensor (16), water level sensor (26), water quality monitoring unit (27), temperature sensor, humidity sensor, and pressure sensor in the sealed test chamber (32), temperature and humidity sensor in the constant temperature and humidity system (45), and high-precision electronic balance (43), respectively. The central controller (5) is used to receive sensor detection signals from each module and send control commands to each module according to the preset test program. The central controller (5) controls the multi-stage vacuum pump group (14), vacuum solenoid valve group (17), ultrasonic atomizer (22), humidity generator (23), dehumidification device (24), automatic water replenishment system (28), constant temperature and humidity system (45), drive mechanism (9) and robotic arm (61) based on temperature, pressure, vacuum degree, water level, water quality and mass data. The central controller (5) includes a control processing unit, data acquisition unit, data storage unit, communication unit, human-machine interaction unit and alarm unit. The control processing unit is used to execute preset vacuum drying program, constant humidity adjustment program, sample migration program and weighing program. The data storage unit is used to store sample information, environmental parameters, weighing data, equipment operating status and alarm information.

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