A method and system for cleaning steel strip embedded residual molecular imprinting

Abstract

The patent discloses a kind of for steel strip embedded type residual molecular imprinting cleaning method and cleaning system, comprising: screening out with string smell feature highly related compound as template molecule;Template molecule is dissolved in porogen with functional monomer, and porogen is toluene-acetonitrile mixture, to obtain pre-polymer;Crosslinking agent and initiator are added in pre-polymer, and heated and stirred to react, to obtain mixed product;Mixed product is removed template molecule by soxhlet extraction, to obtain MIP microsphere, and the particle size of MIP microsphere is 0.5-2 μm;MIP microsphere is dispersed in solvent, and non-ionic surfactant is added to form MIP functional cleaning fluid;MIP functional cleaning fluid is coated on the surface of steel strip, so that residual aroma molecule in the interior of surface micropore is specifically combined with surface and is stripped out from the surface of steel strip together.The patent realizes the purpose of preventing thick pulp method sheet characteristic flavor string smell of cleaning steel strip aroma residue.

Description

Technical Field

[0001] This patent belongs to the field of novel tobacco technology, specifically relating to a method and system for cleaning molecular imprints of steel strip embedded residues. Background Technology

[0002] In the production process of slurry-based thin films, the steel belt serves as the core process carrier and transfer tool, running through the entire process from slurry casting to film peeling. The steel belt is both the substrate for slurry casting, precisely controlling the film thickness through the use of a doctor blade, and a highly efficient heat-conducting element, directly heating the wet film in the drying zone or combining it with hot air to uniformly dehydrate the film. At the same time, as a circular conveyor belt, the steel belt stably feeds the film sequentially into the drying, cooling, and peeling stages.

[0003] When switching brands in the production of slurry-process sheet products, aroma components from different brands (pineapple, orange, tea, blueberry) seep into the micropores of the steel belt surface, forming "embedded residues." Conventional water washing and hot air removal are ineffective in removing these residues, leading to flavor mixing of characteristic aromas in the slurry-process sheet products produced when switching brands. Therefore, a method for cleaning aroma residues from the steel belt is needed to solve this problem. Summary of the Invention

[0004] The purpose of this patent is to provide a method and system for cleaning molecular imprints embedded in steel strips, so as to clean the aroma residues in the steel strips and prevent the characteristic aromas of the thick slurry sheet from being mixed with other flavors.

[0005] To solve the above-mentioned technical problems, this patent adopts the following technical solution: A method for cleaning molecular imprints embedded in steel strips includes the following steps: Step A: Select compounds that are highly correlated with cross-contamination characteristics as template molecules; Step B: The template molecule and functional monomer are dissolved in a porogen, which is a toluene-acetonitrile mixture, to obtain a prepolymer; a crosslinking agent and an initiator are added to the prepolymer, and the mixture is heated and stirred to obtain a mixed product; the template molecule is removed by Soxhlet extraction to obtain MIP microspheres with a particle size of 0.5-2 μm; the MIP microspheres are dispersed in a solvent, and a nonionic surfactant is added to form a MIP functional cleaning fluid; Step C: Apply the MIP functional cleaning fluid to the surface of the steel strip, so that it specifically binds with the residual aroma molecules inside the micropores of the surface and is then peeled off the steel strip surface together.

[0006] Furthermore, step A includes the following steps: Residual aroma molecules inside the micropores of the surface were analyzed by HS-SPME-GC-MS, and combined with sensory evaluation, compounds highly correlated with cross-contamination characteristics were screened as template molecules.

[0007] Furthermore, step B includes the following steps: Step B1: Dissolve the template molecule and functional monomer in a toluene-acetonitrile mixture, wherein the mass ratio of toluene to acetonitrile in the toluene-acetonitrile mixture is 1:(1-2), 1:(2-3), or 1:(3-5), and the functional monomer includes methacrylic acid and / or 4-vinylpyridine; sonicate pre-assemble for 10-13, 13-15, 15-18, or 18-20 minutes to obtain a prepolymer; Step B2: Add crosslinking agent and initiator to the prepolymer, remove oxygen by purging with nitrogen, and stir and react in a water bath at 60-65℃ or 65-70℃ for 20-24 hours or 24-28 hours to obtain a mixed product; the crosslinking agent includes ethylene glycol dimethacrylate, and the initiator includes azobisisobutyronitrile; Step B3: Centrifuge the mixed product, extract with a methanol-glacial acetic acid mixture for 24 hours to remove template molecules, wash, dry, and obtain MIP microspheres.

[0008] Furthermore, the mass ratio of the template molecule to the functional monomer is 1:(3-5), 1:(5-7), or 1:(7-10). The mass ratio of template molecules to crosslinking agents is 1:(25-30), 1:(30-40), 1:(40-50), or 1:(50-60). The mass ratio of template molecule to initiator is 1:(0.12-0.16), 1:(0.16-0.20), 1:(0.20-0.30), or 1:(0.30-0.40). The volume ratio of methanol to glacial acetic acid in the methanol-glacial acetic acid mixture is (8-9):1.

[0009] Furthermore, in step B3, after removing the template molecules, the product is washed with anhydrous methanol and dried at a temperature of 60-80℃.

[0010] Furthermore, step B also includes the following steps: Step B4: The MIP microspheres are dispersed in a solvent. The amount of MIP microspheres added is 2.0-2.5%, 2.5-3.0%, or 3.0-5.0% of the total mass of the MIP functional cleaning fluid. The solvent includes an aqueous ethanol solution to obtain the MIP microsphere solvent. Step B5: Add a nonionic surfactant to the MIP microsphere solvent. The amount of nonionic surfactant added is 0.01-0.03% or 0.03-0.05% of the total mass of the MIP functional cleaning fluid. The nonionic surfactant includes Tween-80. Step B6: After adding the nonionic surfactant, ultrasonically treat for 15 minutes to form the MIP functional cleaning fluid.

[0011] Furthermore, step C includes the following steps: Step C1: Cool the steel strip temperature to below 40°C, apply MIP functional cleaning fluid to the surface of the steel strip, let it stand for 30 minutes, and the MIP microspheres penetrate the surface micropores to specifically bind residual aroma molecules to form specifically bound microspheres. Step C2: The fluid medium is rinsed through the spray nozzle to wash the surface of the steel strip. The fluid shear force is used to peel the specifically bound microspheres off the surface of the steel strip and form rinsing waste liquid. Step C3: The rinsing waste liquid passes through a microsphere filter membrane to trap the specifically bound microspheres. The specifically bound microspheres are collected and enter the desorption tank, where residual aroma molecules are eluted with an ethanol aqueous solution to reduce them back to MIP microspheres.

[0012] Furthermore, step A includes the following steps: Step A1: Collect an air sample 1 mm from the steel strip into a headspace vial and seal it. Step A2: The aroma components of the headspace vial were detected and sensory evaluated using HS-SPME-GC-MS. When the residual concentration of the aroma components was greater than or equal to 10%, the compound with the highest sensory evaluation score and the highest aroma component concentration was selected as the template molecule.

[0013] Furthermore, in step A2, HS-SPME-GC-MS includes the following steps: Use 50 / 30 µm DVB / CAR / PDMS fiber and extract in headspace vials at 30-35℃, 35-40℃, or 40-50℃ for 40-45 min or 45-50 min.

[0014] This patent also provides a cleaning system, which includes a screening module, a cleaning fluid preparation module, and a coating recovery module; The screening module is used to select compounds that are highly correlated with cross-flavor characteristics as template molecules; The cleaning fluid preparation module is used to dissolve template molecules and functional monomers in a porogen, which is a toluene-acetonitrile mixture, to obtain a prepolymer. A crosslinking agent and an initiator are added to the prepolymer, and the mixture is heated and stirred to obtain a mixed product. The mixed product is subjected to Soxhlet extraction to remove template molecules, resulting in MIP microspheres with a particle size of 0.5-2 μm. The MIP microspheres are dispersed in a solvent, and a nonionic surfactant is added to form a MIP functional cleaning fluid. The coating and recovery module is used to coat the MIP functional cleaning fluid onto the surface of the steel strip, so that it specifically binds with the residual aroma molecules inside the micropores of the surface and is then peeled off from the surface of the steel strip.

[0015] This patent provides a method and system for cleaning molecular imprints embedded in steel strips. A specially designed MIP (Molecular Injection Processing) cleaning fluid is applied to the surface of the steel strip for specific binding, removing residual aroma molecules inside the micropores on the surface. Furthermore, a three-step synergistic process of "cold coating - static capture - fluid shear removal" is adopted to achieve targeted cleaning of aroma residues inside the micropores on the equipment surface, solving the problem of cross-contamination of flavors when changing brands. Attached Figure Description

[0016] The above content of this patent and the following detailed embodiments will be better understood when read in conjunction with the accompanying drawings. It should be noted that the drawings are merely examples of the claimed technical solution.

[0017] Figure 1 This is a schematic diagram of the MIP functional cleaning fluid being coated on the surface of a steel strip in this patent. Figure 2 This is a schematic diagram showing the MIP microspheres within the surface micropores of this patent binding with residual aroma molecules to form specifically bound microspheres; Figure 3 This is a partial schematic diagram of the coating recycling module in this patent; Figure 4 This is a schematic diagram of the desorption tank in this patent.

[0018] The reference numerals in the attached figures are explained as follows: MIP microspheres: 1 Steel strip: 2 Surface micropores: 21 Residual aroma molecules: 22 Specific binding microspheres: 23 Spray nozzles: 3 Flow measurement ports: 4 Microsphere filtration membrane: 5 Desorption tank: 6 Ethanol solution: 61 Desorbed filter membrane: 62 Drain port: 63 Detailed Implementation

[0019] The detailed features and advantages of this patent are described below in the specific embodiments. The content is sufficient to enable any person skilled in the art to understand the technical content of this patent and implement it accordingly. Based on the specification, claims and drawings disclosed in this specification, a person skilled in the art can easily understand the related objectives and advantages of this patent.

[0020] This specification also uses several compound terms to describe devices, components, equipment, etc. that include more than one function, or to assign additional functions to a corresponding device, component, equipment, etc. Those skilled in the art will understand that such compound terms can be implemented by a single or multiple devices, components, equipment, etc., as long as they are reasonable under the interpretation rules of this patent terminology.

[0021] It should be noted that in this specification, similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and interpreted in subsequent figures. In this specification and claims, several terms will be used, and unless otherwise indicated, these terms will be defined as having the following meanings: The terms “comprising” or “having” have the same meaning as “containing”, and also include other forms of the term, such as the gerund and singular forms in English, meaning including but not limited to, and not intended to exclude, for example, other elements, components, integers or steps. All other terms used herein for special definition are intended to have the general meaning understood by one of ordinary skill in the art, and in particular, meaning that one of ordinary skill in the art, upon reading the claims, specification and drawings of this patent, can directly and without doubt determine how the technical solution of this patent can be implemented.

[0022] Even if there are incomplete descriptions, omissions, or ambiguities in the grammar, words, punctuation, graphics, symbols, etc. of the claims, specification, and drawings of this patent, a person skilled in the art can still arrive at the only correct understanding by reading the claims, specification, and drawings as a whole without extensive reasoning or experimentation, and effectively exclude various incorrect interpretations that are not aimed at achieving the purpose of this patent.

[0023] Those skilled in the art would first choose to read the claims, specification, and drawings of this patent to reasonably interpret the terms; secondly, they would choose to refer to the relevant definitions in other documents published by the applicant before the filing date to reasonably interpret the terms; thirdly, they would choose the references cited in this patent to reasonably interpret the terms; and finally, they would choose to combine the technical dictionaries, technical manuals, reference books, textbooks, national or industry technical standards, etc., commonly used by those skilled in the art to reasonably interpret the terms.

[0024] All references cited in this application are incorporated herein by way of quotation, to the extent that they do not contradict the disclosure herein. It will be apparent to those skilled in the art that products (apparatus, components, devices, compounds, compositions, materials, etc.) and methods (processes, steps, conditions, parameters, equipment, and test methods, equipment, etc.) not specifically described herein can be applied to the implementation of the inventions fully disclosed herein without the need for excessive experimentation. This patent is intended to cover all functional equivalents known in the art of the methods, apparatus, apparatus components, materials, processes, and techniques specifically described herein. All cited references include: The following publications are included: Marks' Standard Handbook for Mechanical Engineers (11th edition and other editions prior to this patent application date), published by McGraw-Hill, Inc.; DeGarmo's Materials and Processes in Manufacturing (13th edition and other editions prior to this patent application date), published by Wiley; Machinery's Handbook (32nd edition and other editions prior to this patent application date), published by IndustrialPress Inc.; Mechanical Design Handbook (6th edition and other editions prior to this patent application date), edited by Cheng Daxian, published by Chemical Industry Press; and Modern Mechanical Design Handbook (6th edition and other editions prior to this patent application date), edited by Wen Bangchun, published by Machinery Industry Press.

[0025] This patent will now be described with reference to the accompanying drawings, in which similar reference numerals denote similar elements. While specific structures and arrangements are discussed, it should be understood that this is done merely for illustrative purposes. Those skilled in the art will recognize that other structures and arrangements can be used without departing from the spirit and scope of this patent. It will be clear to those skilled in the art that this patent can also be used in a variety of other applications.

[0026] This patent provides a method for cleaning molecular imprints embedded in steel strips, comprising the following steps: S1, Constructing MIP functional cleaning fluid a) Template molecule screening: Detection was performed using HS-SPME-GC-MS. An air sample was collected 1 mm from the steel strip and sealed in a headspace vial. At the same time, a blank sample was collected from the field for background subtraction.

[0027] Solid-phase microextraction: 50 / 30 µm DVB / CAR / PDMS fibers were selected and extracted in the headspace gas phase at 40 °C for 45 min. Pre-equilibration was performed for 15 min before extraction to ensure stable partitioning.

[0028] GC-MS instrument analysis: The fibers were desorbed without splitting at the injection port for 5 min at 250 ℃, and separated using a medium polarity chromatographic column with programmed temperature rise. The mass spectrometer was used to collect ions at m / z 29–350 in full scan mode with EI source.

[0029] Qualitative and quantitative: Qualitative analysis was performed by searching the NIST spectral library (e.g., searching the corresponding library for the product with blueberry flavor) and comparing the retention index with the standard; quantitative analysis was performed by establishing a gaseous standard curve using the external standard method, and the relative content of components without standard was expressed as a percentage of peak area.

[0030] Sensory evaluation: A sensory evaluation team of at least 8 evaluators was formed to score the cross-contamination characteristics: the evaluators smelled an air sample 1 mm away from the steel strip, established common descriptive words for "cross-contamination" (such as "blueberry", "tea", "sour", "stinky", etc.), and scored the intensity of each smell (0-10 points, 0=none, 1-3 slightly, 4-6 obvious, 7-9 strong, 10=very strong) and obtained the average score, and ranked the smell with the highest score (e.g., blueberry).

[0031] Fifteen air samples were collected from different steel belt production lines at a distance of 1 mm. The concentrations of all aroma components were quantitatively detected using HS-SPME-GC-MS. At the same time, sensory evaluation was conducted by tasters. The results are shown in Table 1.

[0032] Table 1: Comparison of Residual Concentrations of Aroma Components

[0033] As shown in Table 1, when the residual concentration of aroma components is greater than or equal to 10%, the aroma can be perceived by the senses, meaning that using this steel belt to produce other brands of slurry-process sheets will result in severe cross-contamination of flavors. However, when the residual concentration of aroma components is less than or equal to 2%, the aroma is basically undetectable, thus avoiding cross-contamination.

[0034] If the highest sensory evaluation score matches the highest concentration of aroma component detected by HS-SPME-GC-MS, it indicates its effectiveness. When the residual concentration of aroma component in the air sample is greater than 2.0%, the compound with the highest sensory evaluation score and the highest concentration of aroma component detected by HS-SPME-GC-MS is selected as the template molecule. Analysis of the residue on the steel belt surface after the previous brand's production, combined with sensory evaluation, filters are selected based on a high correlation with cross-contamination characteristics. Thus, by correlating volatile compounds detected by GC-MS with human sensory evaluation data, the compound with the "largest negative contribution" to cross-contamination is selected as the template molecule. This process relies not only on chemical concentration but also emphasizes the matching of odor activity and sensory characteristics.

[0035] b) Preparation of MIP microspheres: Precipitation polymerization method was used.

[0036] 0.5 mmol of template molecule and 3.0 mmol of functional monomer were dissolved in a toluene-acetonitrile mixed porogen. The functional monomer was selected according to the polarity of the template, either MAA (methacrylic acid) or 4-VP (4-vinylpyridine). The prepolymer was obtained by ultrasonic pre-assembly at 130W for 15 minutes.

[0037] Add 15-25 mmol of crosslinking agent EDMA (ethylene glycol dimethacrylate) and 0.08-0.15 mmol of initiator AIBN (azobisisobutyronitrile) to the prepolymer, remove oxygen by purging with nitrogen, and stir the mixture in a water bath at 65°C for 24 hours to obtain a mixed product.

[0038] The mixed product was centrifuged and then Soxhlet extracted with a methanol-glacial acetic acid mixture (volume ratio 8-9:1) for 24 hours to remove template molecules. The product was then washed with anhydrous methanol and dried under vacuum at 70±3℃ to obtain monodisperse MIP microspheres with an average particle size of 0.5-2 μm.

[0039] c) Preparation of functional fluid: Disperse MIP microspheres at a mass fraction of 2.5% in a water-ethanol mixture (volume ratio 1:0.8-1.2) to obtain MIP microsphere solvent; continue to add 0.03% of the nonionic surfactant Tween-80 to the MIP microsphere solvent, and sonicate for 15 minutes to form a uniformly suspended MIP functional cleaning fluid.

[0040] S2, Cold Coating and Static Capture

[0041] With the production line shut down and the steel strip temperature cooled to below 40°C, the MIP functional cleaning fluid is applied to the steel strip surface. After standing for 30 minutes, the MIP microspheres penetrate the surface micropores and specifically bind residual aroma molecules through imprinted holes.

[0042] like Figure 1-2As shown, the MIP functional cleaning fluid is uniformly coated on the surface of the steel belt. The MIP microspheres 1 in the MIP functional cleaning fluid enter the surface micropores 21 of the steel belt 2. The MIP microspheres 1 specifically bind to the residual aroma molecules 22 inside the surface micropores, thereby forming specifically bound microspheres 23.

[0043] S3, Fluid flushing to remove residue

[0044] like Figure 3 As shown, a fluid medium (optionally distilled water) with a flow rate of 1.5 m / s is used to rinse the surface of the steel belt through the spray nozzle 3. The fluid shear force is used to peel off the specific bound microspheres that are bound to residual aroma molecules from the surface and form rinsing waste liquid that is washed away.

[0045] S4, MIP recycling and regeneration

[0046] The rinsing waste liquid passes through side outlet 4 and is filtered by a 0.5 μm microsphere filter membrane 5, where specifically bound microspheres 23 are retained. A certain amount of the specifically bound microspheres 23 is collected and then enters the desorption tank 6. Figure 4 As shown, elution and regeneration are performed using a 65°C ethanol solution (optionally a 70% aqueous ethanol solution) 61. After elution for 30 minutes, residual aroma molecules 22 in the specifically bound microspheres 23 are eluted into the ethanol solution 61, thereby reducing the specifically bound microspheres 23 to MIP microspheres 1. The mixture of ethanol and residual aroma molecules is discharged by opening the drain port 63 at the bottom of the desorption tank 6. The MIP microspheres 1 in the desorption tank 6 are dried and recycled.

[0047] Example 1

[0048] The molecular imprint removal method for the reconstituted tobacco leaves of the previous grade of fruit-flavored heated cigarette produced by the slurry-process sheet production steel belt in this embodiment includes the following steps: S1, Constructing MIP functional cleaning fluid HS-SPME-GC-MS was used to analyze the residues on the steel strip surface after the previous grade was produced. Combined with sensory evaluation by smell, a compound that was highly correlated with cross-contamination characteristics was selected as a template molecule.

[0049] An air sample was collected 1 mm from the steel strip and sealed in a headspace vial. At the same time, a blank sample was collected from the field for background subtraction.

[0050] 50 / 30 µm DVB / CAR / PDMS fibers were selected and extracted in the headspace gas phase at 40 °C for 45 min. Pre-equilibration was performed for 15 min before extraction to ensure stable partitioning.

[0051] The fibers were desorbed without splitting at the injection port for 5 min at 250 ℃, and separated using a medium polarity chromatographic column with programmed temperature rise. The mass spectrometer was used to collect ions at m / z 29–350 in full scan mode with EI source.

[0052] Qualitative analysis was performed by searching the NIST spectral library and comparing retention indices with standards; quantitative analysis was performed by establishing a gaseous standard curve using the external standard method. The relative content of components without standards was expressed as a percentage of peak area. The detected components and quantitative results are shown in Table 2.

[0053] Table 2: Test Results of Steel Strip for Fruit-Flavored Heated Cigarettes

[0054] A sensory evaluation team consisting of at least 8 evaluators was formed. The evaluators smelled an air sample 1 mm away from the steel strip, established common descriptive terms for aroma types, scored the intensity of each odor they smelled, and calculated the average score. The results are shown in Table 3.

[0055] Table 3: Sensory Evaluation Results

[0056] According to Table 2-3, the residual concentration of residue on the steel belt surface after the production of fruit-flavored heated cigarette reconstituted tobacco is about 10%, and the steel belt needs to be cleaned to prevent cross-contamination of flavors. The overall evaluation of aroma components and sensory evaluation shows the consistency of the results in Table 4.

[0057] Table 4: Comparison Table of Overall Evaluation Conformity

[0058] As shown in Table 4, the blueberry aroma (linalool) ranked highest in both detection concentration and sensory evaluation, indicating that linalool was selected as the template molecule.

[0059] 0.5 mmol template molecule and 3.0 mmol functional monomer were dissolved in a toluene-acetonitrile mixed porogen (acetonitrile:toluene = 3:1). The functional monomer was selected according to the polarity of the template, either MAA (methacrylic acid) or 4-VP (4-vinylpyridine). The prepolymer was obtained by ultrasonic pre-assembly at 130W for 15 minutes.

[0060] 20 mmol of crosslinking agent EDMA (ethylene glycol dimethacrylate) and 0.1 mmol of initiator AIBN (azobisisobutyronitrile) were added to the prepolymer. After purging with nitrogen to remove oxygen, the mixture was stirred in a water bath at 65°C for 24 hours to obtain a mixed product.

[0061] The mixed product was centrifuged and then Soxhlet extracted with a methanol-glacial acetic acid mixture (9:1, volume ratio) for 24 hours to remove template molecules. The product was then washed with anhydrous methanol and dried under vacuum at 70±3℃ to obtain monodisperse MIP microspheres with an average particle size of 0.5-2 μm.

[0062] MIP microspheres were dispersed at a mass fraction of 2.5% in a water-ethanol mixture (volume ratio 1:1) to obtain the MIP microsphere solvent; 0.03% of the nonionic surfactant Tween-80 was added to the MIP microsphere solvent, and the mixture was ultrasonically treated at 130W for 15 minutes to form a uniformly suspended MIP functional cleaning fluid.

[0063] S2, Cold Coating and Static Capture

[0064] With the production line shut down and the steel strip temperature cooled to below 40°C, the MIP functional cleaning fluid is applied to the steel strip surface. After standing for 30 minutes, the MIP microspheres penetrate the surface micropores and specifically bind residual aroma molecules through imprinted cavities, forming specifically bound microspheres.

[0065] S3, Fluid flushing to remove residue

[0066] The surface of the steel belt is rinsed through a spray nozzle with a fluid medium (distilled water can be selected) at a flow rate of 1.5 m / s. The fluid shear force is used to peel off the specific binding microspheres that bind residual aroma molecules from the surface and form rinsing waste liquid that is washed away. The residual aroma molecule concentration in the steel belt is detected to be ≤2%, which meets the qualified standard.

[0067] S4, MIP recycling and regeneration

[0068] The rinsing waste liquid flows through a side outlet and is filtered through a 0.5 μm microsphere membrane to trap the specifically bound microspheres. A certain amount of these microspheres is collected and enters the desorption tank, where they are eluted and regenerated using a 65°C ethanol solution. After elution for 30 minutes, residual aroma molecules from the microspheres are eluted into the ethanol solution, thus reducing the microspheres to MIP microspheres. The mixture of ethanol and residual aroma molecules is discharged through the drain outlet at the bottom of the desorption tank. The MIP microspheres in the desorption tank are dried and recycled.

[0069] This patented method for cleaning molecular imprints of embedded aroma residues on the surface of thin steel strips produced by the slurry method has the following advantages: 1. It solves the problem of residual aroma on the surface of the thin steel strip in the thick slurry method, which leads to cross-contamination of flavors when changing brands, effectively improving the stability of product quality and ensuring the consistency of product flavor.

[0070] 2. Low cost and easy to industrialize: The raw materials for the preparation of MIP microspheres are readily available and the process is simple. No complicated equipment is required, and they can be reused after regeneration, which greatly reduces production costs. The supporting equipment has a simple structure, does not require modification of existing production lines, has strong adaptability, and can be directly applied to the slurry-based thin film production line, which is convenient for large-scale promotion.

[0071] The terms and expressions used in this specification are for illustrative purposes and not for limitation. Their use is not intended to exclude any equivalents of the features or portions thereof shown, but rather to facilitate the understanding that various modifications may be possible within the scope of this patent claim. Therefore, it should be understood that while this patent has been specifically disclosed through preferred embodiments, exemplary embodiments, and optional features, variations or modifications of the concepts disclosed herein may be adopted by those skilled in the art, and such variations and modifications are therefore considered to be within the scope of this patent as defined by the appended claims. The specific embodiments given in this specification are examples of useful embodiments of this patent, and it will be apparent to those skilled in the art that this patent can be implemented using many variations of the devices, device components, and method steps disclosed herein.

[0072] The foregoing description of specific embodiments fully discloses the general features of this patent, enabling others to easily modify and / or adapt such embodiments for various applications by applying knowledge within the scope of the art, without excessive experimentation or deviation from the general concept of this patent. Therefore, based on the teachings and guidance provided herein, it is intended that such modifications and alterations be included within the meaning and scope of equivalents of the disclosed embodiments. It should be understood that the wording or terminology used herein is for descriptive purposes and not intended to be limiting; thus, the wording or terminology in this specification will be interpreted by those skilled in the art based on the foregoing teachings and guidance.

[0073] Furthermore, the scope of this patent should not be limited to any of the exemplary embodiments described above, but only to the appended claims and their equivalents.

Claims

1. A method for cleaning molecular imprints embedded in steel strips, characterized in that, Includes the following steps: Step A: Select compounds that are highly correlated with cross-contamination characteristics as template molecules; Step B: The template molecule and functional monomer are dissolved in a porogen, wherein the porogen is a toluene-acetonitrile mixture, to obtain a prepolymer; a crosslinking agent and an initiator are added to the prepolymer, and the mixture is heated and stirred to obtain a mixed product; the template molecule is removed from the mixed product by Soxhlet extraction to obtain MIP microspheres with a particle size of 0.5-2 μm; the MIP microspheres are dispersed in a solvent, and a nonionic surfactant is added to form a MIP functional cleaning fluid; Step C: The MIP functional cleaning fluid is coated onto the surface of the steel strip, thereby specifically binding with the residual aroma molecules inside the micropores of the surface and being peeled off from the surface of the steel strip together.

2. The method for cleaning molecular imprints embedded in steel strips according to claim 1, characterized in that, Step A includes the following steps: The residual aroma molecules inside the surface micropores were analyzed by HS-SPME-GC-MS, and combined with sensory evaluation, compounds highly correlated with cross-contamination characteristics were screened as template molecules.

3. The method for cleaning molecular imprints embedded in steel strips according to claim 1, characterized in that, Step B includes the following steps: Step B1: Dissolve the template molecule and the functional monomer in the toluene-acetonitrile mixture, wherein the mass ratio of toluene to acetonitrile in the toluene-acetonitrile mixture is 1:(1-2), 1:(2-3), or 1:(3-5), and the functional monomer includes methacrylic acid and / or 4-vinylpyridine; perform ultrasonic pre-assembly for 10-13, 13-15, 15-18, or 18-20 minutes to obtain the prepolymer; Step B2: Add the crosslinking agent and the initiator to the prepolymer, remove oxygen by purging with nitrogen, and stir and react in a water bath at 60-65°C or 65-70°C for 20-24 hours or 24-28 hours to obtain the mixed product; the crosslinking agent includes ethylene glycol dimethacrylate, and the initiator includes azobisisobutyronitrile; Step B3: The mixed product is centrifuged, and the template molecules are removed by Soxhlet extraction with a methanol-glacial acetic acid mixture for 24 hours. After washing and drying, the MIP microspheres are obtained.

4. The method for cleaning molecular imprints embedded in steel strips according to claim 3, characterized in that, The mass ratio of the template molecule to the functional monomer is 1:(3-5), 1:(5-7), or 1:(7-10). The mass ratio of the template molecule to the crosslinking agent is 1:(25-30), 1:(30-40), 1:(40-50), or 1:(50-60). The mass ratio of the template molecule to the initiator is 1:(0.12-0.16), 1:(0.16-0.20), 1:(0.20-0.30), or 1:(0.30-0.40). The volume ratio of methanol to glacial acetic acid in the methanol-glacial acetic acid mixture is (8-9):

1.

5. The method for cleaning molecular imprints embedded in steel strips according to claim 3, characterized in that, In step B3, after removing the template molecules, the product is washed with anhydrous methanol, and the drying temperature is 60-80℃.

6. The method for cleaning molecular imprints embedded in steel strips according to claim 3, characterized in that, Step B further includes the following steps: Step B4: The MIP microspheres are dispersed in a solvent, and the amount of MIP microspheres added is 2.0-2.5%, 2.5-3.0%, or 3.0-5.0% of the total mass of the MIP functional cleaning fluid. The solvent includes an aqueous ethanol solution to obtain the MIP microsphere solvent. Step B5: Add the nonionic surfactant to the MIP microsphere solvent. The amount of nonionic surfactant added is 0.01-0.03% or 0.03-0.05% of the total mass of the MIP functional cleaning fluid. The nonionic surfactant includes Tween-80. Step B6: After adding the nonionic surfactant, the mixture is ultrasonically treated for 15 minutes to form the MIP functional cleaning fluid.

7. The method for cleaning molecular imprints embedded in steel strips according to claim 1, characterized in that, Step C includes the following steps: Step C1: The steel strip temperature is cooled to below 40°C, the MIP functional cleaning fluid is coated on the surface of the steel strip, and it is left to stand for 30 minutes. The MIP microspheres penetrate the surface micropores and specifically bind the residual aroma molecules to form specifically bound microspheres. Step C2: The fluid medium is rinsed through the spray nozzle to wash the surface of the steel strip, and the specific binding microspheres are peeled off the surface of the steel strip by the fluid shear force to form rinsing waste liquid; Step C3: The rinsing waste liquid is filtered through a microsphere filter membrane to retain the specifically bound microspheres. The specifically bound microspheres are collected and sent to a desorption tank, where the residual aroma molecules are eluted with an ethanol aqueous solution to reduce them back to the MIP microspheres.

8. The method for cleaning molecular imprints embedded in steel strips according to claim 1, characterized in that, Step A includes the following steps: Step A1: Collect an air sample 1 mm from the steel strip into a headspace vial and seal it. Step A2: The headspace vial is subjected to aroma component detection and sensory evaluation using HS-SPME-GC-MS. When the residual concentration of the aroma component is greater than or equal to 10%, the compound with the highest sensory evaluation score and the highest aroma component concentration is selected as the template molecule.

9. The method for cleaning molecular imprints embedded in steel strips according to claim 8, characterized in that, In step A2, the HS-SPME-GC-MS includes the following steps: Using 50 / 30 µm DVB / CAR / PDMS fiber, extract for 40-45 min or 45-50 min in the headspace vial at 30-35℃, 35-40℃ or 40-50℃.

10. A cleaning system, characterized in that, The cleaning system includes a screening module, a cleaning fluid preparation module, and a coating recovery module; The screening module is used to screen out compounds that are highly correlated with cross-flavor characteristics as template molecules; The cleaning fluid preparation module is used to dissolve the template molecules and functional monomers in a porogen, wherein the porogen is a toluene-acetonitrile mixture, to obtain a prepolymer; a crosslinking agent and an initiator are added to the prepolymer, and the mixture is heated and stirred to obtain a mixed product; the mixed product is subjected to Soxhlet extraction to remove the template molecules, thereby obtaining MIP microspheres with a particle size of 0.5-2 μm; the MIP microspheres are dispersed in a solvent, and a nonionic surfactant is added to form a MIP functional cleaning fluid; The coating and recovery module is used to coat the MIP functional cleaning fluid onto the surface of the steel strip, so that it specifically binds with the residual aroma molecules inside the micropores of the surface and is then peeled off from the surface of the steel strip.

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