Method for judging reclaimed material of inner barrel material of washing machine

Abstract

The invention discloses a method for judging a reclaimed material of an inner barrel material of a washing machine, which comprises the following steps of: detecting whether a grease compound is contained or not, performing primary extraction on a crushed reclaimed material if the grease compound is not detected, and performing secondary extraction on the crushed reclaimed material if a surfactant is directly confirmed to be contained in the crushed reclaimed material. Judging that the material is the regenerated material of the washing machine inner barrel and ending; otherwise, separation and detection are performed, so that whether the surfactant is contained or the type of the contained surfactant is further determined. According to the method, step-by-step progressive testing is carried out through a step-by-step method, whether the washing machine inner barrel material is the regenerated material or not is preliminarily judged through one-time extraction, and separation and further detection are carried out under the condition that direct judgment cannot be carried out, so that the possible regenerated material of the washing machine inner barrel material is rapidly screened out, time and resources are saved, and the efficiency is improved. And the method is particularly beneficial to the treatment of large-batch samples.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste plastic treatment, in particular to a method for judging recycled material in a drum of a washing machine. Background Art

[0002] With the rapid development of my country's plastics industry, the recycling and reuse of waste plastics has become an important environmental protection issue. The material of the drum of the washing machine is pure, the use environment is single, the output is large, and the recycling channels are stable. Therefore, it is a good performance material as a recycled material and is paid attention to by the recycling industry.

[0003] At present, the method of judging whether the recycled material is the drum material of the washing machine mainly relies on the detection of specific components. Although this method is accurate, it has the following shortcomings: the detection process is complicated, and it is necessary to conduct multi-step chemical analysis of the recycled material to determine its specific composition. The operation is cumbersome and the technical requirements of the operator are high. The cost is high, which is not conducive to large-scale promotion and application. The detection cycle is long and the whole process takes a long time, which is difficult to meet the needs of rapid judgment. Some detection methods are highly dependent on instruments and equipment, which limits their application in grassroots recycling companies.

[0004] Therefore, how to quickly and effectively determine whether recycled materials are the drum materials for washing machines has always been a technical challenge in the industry. Summary of the invention

[0005] The purpose of the present invention is to provide a method that can accurately determine whether the recycled material is the recycled material of the inner barrel of a washing machine.

[0006] In order to achieve the above object, the present invention provides a method for determining whether the drum material in a washing machine is recycled material, comprising:

[0007] Pre-processing to obtain recycled material and crushed material;

[0008] The recycled material and the grease residue extractant are fully contacted for extraction. If grease compounds are detected, it is determined that the recycled material is not the recycled material of the drum material of the washing machine, and the determination process ends;

[0009] If no oily compound is detected, the recycled material and the crushed material are fully contacted with the extraction solvent for extraction;

[0010] If one type of surfactant is extracted, it is judged to be recycled material from the drum of the washing machine. If two or more different types of surfactants are extracted or no surfactant is extracted, separate measurements are performed;

[0011] If one or more surfactants are measured after separation, it is judged to be recycled material from the drum material of the washing machine. If no surfactant is measured after separation, it is determined not to be recycled material from the drum material of the washing machine.

[0012] Optionally, the pretreatment process includes crushing, washing, drying and removing impurities from the recycled material to obtain the recycled material crushed material.

[0013] Optionally, the extraction solvent includes ethanol and isopropanol, and the mass ratio of ethanol to isopropanol is 80:20 to 85:15.

[0014] Optionally, the extraction solvent includes ethanol, isopropanol and methanol, and the mass ratio of ethanol, isopropanol and methanol is 80:15:5 to 75:20:5.

[0015] Optionally, the process of fully contacting the recycled material and the extraction solvent for extraction includes:

[0016] A plurality of samples of the recycled material and crushed material are selected, and respectively subjected to Soxhlet extraction, the extraction solvent is heated to boiling, and the plurality of extracts are collected and concentrated together for infrared testing, and the types of surfactants present are obtained based on the infrared spectrum obtained by the infrared test.

[0017] Optionally, the heating temperature range during the extraction process is 65 to 85° C., and the extraction time is 24 h to 48 h.

[0018] Optionally, the surfactant is a combination of one or more of anionic surfactants, cationic surfactants, amphoteric surfactants or non-ionic surfactants.

[0019] Optionally, select multiple samples and fully contact them with the grease residue extraction agent for extraction, combine the multiple filtered extracts for concentration, and take the concentrated solution for infrared spectroscopy analysis or gas chromatography-mass spectrometry analysis. If the characteristic peaks of grease compounds are detected, it is proved that the material is not recycled from the drum material of the washing machine.

[0020] Optionally, the oil residue extractant includes chloroform or carbon tetrachloride.

[0021] Compared with the prior art, the method for determining whether the drum material in a washing machine is recycled material provided by the present invention performs progressive testing through a step-by-step method, and preliminarily determines whether it is recycled material in the drum material of the washing machine through a single extraction. If it cannot be directly determined, separation and further testing are performed, thereby quickly determining whether it is recycled material in the drum material of the washing machine, saving time and resources, and being particularly beneficial for the processing of large quantities of samples; ensuring the type of recycled materials, avoiding recycled materials of unknown origin from entering the production process, and improving the quality and market competitiveness of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a flow chart of a method for determining whether drum material in a washing machine is recycled material. DETAILED DESCRIPTION

[0023] The present invention will be described in more detail below, wherein preferred embodiments of the present invention are shown, and it should be understood that those skilled in the art can modify the present invention described herein, and still achieve the beneficial effects of the present invention. Therefore, the following description should be understood as being widely known to those skilled in the art, and not as a limitation of the present invention.

[0024] The present invention is described in more detail by way of example in the following paragraphs. Advantages and features of the present invention will become more apparent from the following description.

[0025] The most basic feature of recycled materials is that they carry some traces of use, which can characterize their use environment. How to identify whether the recycled materials are the inner barrel materials of the washing machine or new materials through effective traces of use is the problem that the present invention aims to solve. During the use of washing machines, detergents, washing powders, washing liquids, softeners and other products are used. Washing products will have fixed residues inside the materials. Through the ingredients of washing powders, washing liquids, and washing soaps, representative substances are selected for testing according to the formula of laundry cleaning, and the test results are used to verify whether the recycled materials are the inner barrel materials of the washing machine.

[0026] The residues in the inner drum of the washing machine are representative surfactants, including anionic surfactants, cationic surfactants, amphoteric surfactants and non-ionic surfactants. At the same time, in order to distinguish whether the recycled material is the inner drum material of the washing machine or the recycled material of kitchen utensils, grease residue detection is also added to increase the specificity of the inner drum material of the washing machine.

[0027] The present invention provides a method for determining the recycled material of the drum material in the washing machine, please refer to Figure 1 , including the following steps:

[0028] S1, pre-processing to obtain recycled material and crushed material;

[0029] S2, fully contacting the recycled material and the grease residue extractant to extract, if grease compounds are detected, it is determined that it is not the recycled material of the drum material in the washing machine, and the judgment process ends;

[0030] S3. If no oily compounds are detected, the recycled material and the crushed material are fully contacted with the extraction solvent for extraction;

[0031] S4. If one type of surfactant is extracted, it is judged to be recycled material from the drum of the washing machine. If two or more different types of surfactants are extracted or no surfactant is extracted, separate measurement is performed;

[0032] S5. If one or more surfactants are measured after separation, it is determined to be recycled material from the drum material of the washing machine. If no surfactant is measured after separation, it is determined not to be recycled material from the drum material of the washing machine.

[0033] In this embodiment, most of the surfactant penetrates into the interior of the recycled material to characterize its use environment, and the surface of the material is cleaned to eliminate the interference of the surfactant remaining on the surface of the material.

[0034] Furthermore, the pretreatment in step S1 includes crushing, washing, drying and removing impurities from the recycled material to obtain the recycled material crushed material.

[0035] In step S2, specifically, multiple samples are selected and fully contacted with the grease residue extractant for extraction, multiple filtered extracts are combined and concentrated, and the concentrated solution is subjected to infrared spectroscopy analysis or gas chromatography-mass spectrometry analysis. If characteristic peaks of grease compounds are detected, it is proved that the sample is not recycled material from the drum of the washing machine.

[0036] Furthermore, the grease residue extractant includes chloroform or carbon tetrachloride.

[0037] In a specific example, the process of detecting oil compounds specifically includes the steps of:

[0038] 1. Sample pretreatment

[0039] Sampling: Randomly select multiple samples from the recycled and crushed materials, and the weight of each sample is about 10 to 20 grams.

[0040] Crushing: crush the sampled material to increase the contact area between the sample and the extractant and improve the extraction efficiency.

[0041] Sieving: Sieve the crushed sample to remove larger particles and make the sample particle size uniform.

[0042] 2. Extraction process

[0043] Selection of extraction agent: According to the properties of the oil residue, select a suitable extraction agent, such as chloroform or carbon tetrachloride.

[0044] Extraction: Place the pretreated sample into the extractor, add the extractant, and mix the sample and the extractant thoroughly.

[0045] The extraction time was 24 hours.

[0046] Filtration: After the extraction is completed, the extract is filtered to remove solid impurities.

[0047] 3. Mixed Concentration

[0048] Combining: Combine multiple filtered extracts in preparation for concentration.

[0049] Concentration: Use a rotary evaporator or other concentration equipment to concentrate the extract.

[0050] Transfer: Transfer the concentrate to a sample bottle and set aside.

[0051] 4. Testing and Analysis

[0052] Infrared spectrum analysis: Take an appropriate amount of the concentrate and perform infrared spectrum analysis. If the spectrum shows characteristic peaks of oils and fats, such as the carbonyl peak (1740cm^ -1 ), methylene peak (1460cm^ -1 ) etc., it can be determined that the sample contains oily substances.

[0053] GCMS analysis: Take an appropriate amount of concentrated liquid and perform gas chromatography-mass spectrometry analysis. By comparing the standard substance spectrum, if the characteristic peaks of oily compounds are detected, the presence of oily substances in the sample can be confirmed.

[0054] Furthermore, in step S3, the extraction solvent includes ethanol and isopropanol, and the mass ratio of ethanol to isopropanol is 80:20 to 85:15.

[0055] Furthermore, the extraction solvent includes ethanol, isopropanol and methanol, and the mass ratio of ethanol, isopropanol and methanol is 80:15:5 to 75:20:5. The extraction effects of extraction solutions with different ratios are shown in Table 1.

[0056] Table 1

[0057]

[0058]

[0059] The extraction was performed using a combination of extraction solvents in a ratio of 4. The anionic surfactants were extracted to a concentration of 1 ppm for UV spectrophotometer measurement, the nonionic surfactants were extracted to a concentration of 5 ppm for HPLC measurement, and the cationic and amphoteric surfactants were extracted to a concentration of 5x10 -5 Concentrations in mol / l are used for two-phase titrations.

[0060] The extraction was performed using a combination of extraction solvents in a ratio of 5. The anionic surfactant was extracted to a concentration of 1 ppm for UV spectrophotometer measurement, the nonionic surfactant was extracted to a concentration of 1 ppm for HPLC measurement, and the cationic surfactant and amphoteric surfactant reached a concentration of 5x10 -5 Concentrations in mol / l are used for two-phase titrations.

[0061] Specifically, in step S3, the process of fully contacting the recycled material and the extraction solvent for extraction includes: selecting multiple samples, respectively subjecting them to Soxhlet extraction, heating the extraction solvent to boiling, collecting multiple extracts together for concentration, conducting infrared testing on the concentrated extracts, and obtaining the type of surfactant present based on the infrared spectrum obtained from the infrared test.

[0062] In a specific example, step S3 specifically includes the following steps:

[0063] S31. Sample preparation and processing:

[0064] Sample collection: Randomly collect multiple samples from recycled and crushed materials to ensure that the samples are representative.

[0065] Sample pretreatment: crush the sample into small particles for easy extraction.

[0066] Sample loading: Load the processed sample into the extraction sleeve of the Soxhlet extractor.

[0067] S32, Soxhlet extraction process:

[0068] Heating: Turn on the Soxhlet extractor and heat the extraction solvent to boiling point, allowing it to evaporate and reflux through the condenser.

[0069] Extraction: Ensure that the sample is fully exposed to the boiling extraction solvent until the color of the extraction solvent no longer changes, indicating that most of the target substance has been extracted.

[0070] Collect the extract.

[0071] S33, extract combination and concentration

[0072] Combined extracts: Combined multiple extracts collected.

[0073] Concentration: Use a rotary evaporator or other concentrating equipment to heat the extract under reduced pressure to remove the solvent and obtain a concentrated solution.

[0074] S34, infrared test

[0075] Sample preparation: Take a small amount of the concentrate and perform appropriate drying to remove residual solvent.

[0076] Infrared spectrum analysis: Apply the processed sample on the sample stage of the infrared spectrometer and perform infrared spectrum scanning.

[0077] Data collection: Record the infrared spectrum, including the location, intensity and shape of the absorption peaks.

[0078] S35. Identification of surfactant types

[0079] Analyze infrared spectra: Compare with standard infrared spectra library to identify characteristic absorption peaks, such as carbonyl (C=O), hydroxyl (OH), amine (NH), etc.

[0080] Identification of surfactants: Based on the characteristic absorption peaks, the type of surfactant present in the sample can be inferred.

[0081] For example, anionic surfactants usually contain functional groups such as sulfonic acid (-SO3H) and carboxylic acid (-COOH), and their characteristic absorption peaks are between 1200 and 1000 cm^ -1 .

[0082] Cationic surfactants: usually contain quaternary ammonium salt structure, characteristic absorption peak at 1000-950cm^ -1 .

[0083] Amphoteric surfactants: contain functional groups with both positive and negative charges, such as betaine structure, and the characteristic absorption peak may be at 1600-1500cm^ -1 .

[0084] Nonionic surfactants: usually contain functional groups such as ether bonds (-O-) and hydroxyl groups (-OH), and the characteristic absorption peak may be between 1050-800cm^ -1 .

[0085] Through the above steps, the extraction process of surfactants in recycled material crushing materials can be systematically completed, and through further testing and identification processes, it can be determined whether anionic, cationic, amphoteric or non-ionic surfactants are present.

[0086] Furthermore, the heating temperature range during the extraction process is 65 to 85° C., and the extraction time is 24 h to 48 h.

[0087] The surfactant is selected from the group consisting of anionic surfactants, cationic surfactants, amphoteric surfactants and nonionic surfactants.

[0088] Furthermore, in steps S4 and S5, if a surfactant is extracted, it is determined to be recycled material from the drum material of the washing machine, and the determination process is terminated.

[0089] If the type of surfactant detected is not one but two or more different types or no surfactant is detected, further separation measurement is required to further confirm whether a surfactant is contained or what specific type of surfactant it is.

[0090] It should be noted that, in this embodiment, when more than one type of surfactant is detected, different types of surfactants may affect each other, which may affect the confirmation of the type of surfactant present, so separation and measurement are required.

[0091] In a specific example, taking step S4 as an example, the process of separation measurement includes the following steps:

[0092] S41, the dried recovered material is dissolved in a 40:60 isopropanol aqueous solution, heated to 50°C, and passed through a combined anion and cation mixed column, preferably a Dowex 50W-X2 and Merck Lewatit MP 7080 connection column. The nonionic surfactant is retained in the eluate.

[0093] S42. In order to avoid containing different surfactants at the same time and to separate the types, the dried recovered material is preferentially dissolved in methanol and anion separation is performed through an anion exchange column, preferably zerolit M-IP SRA 151. After the solvent passes through the column, the column is washed with 2 mol / L NH4OH ethanol solution to obtain a pure anionic surfactant reagent.

[0094] S43. Pass the methanol solvent from which the anionic surfactant has been extracted in step S42 through an amphoteric surfactant extraction column, preferably Bio-Rad AG-X2, OH-type, and wash with 2 mol / L HCL ethanol solution to obtain a pure amphoteric surfactant reagent; the remainder is mainly a cationic surfactant.

[0095] S44. The four separated surfactants are measured separately. The anionic and cationic surfactant sensing electrodes are potentiometrically titrated. The voltage shows a significant change, which can also be determined by the first-order derivative curve. The endpoint of the titration can be seen by the obvious change of the peak of the first-order derivative curve, proving the presence of surfactants. The anionic surfactant is first titrated with Hamming 1622 to determine the total active substances, and then after acid hydrolysis, the sulfonated hydrocarbon compounds are titrated with BEC. Cationic and amphoteric surfactants are potentiometrically titrated with sodium dodecyl sulfate (SDS) and are not restricted by acid-base environments. The titration determination methods of anionic surfactants and cationic surfactants are consistent.

[0096] S45, auxiliary identification test: the extract of step S42 is dissolved in water, the anionic surfactant sodium linear alkylbenzene sulfonate uses a methylene blue solution to dissolve and react the extract, and a spectrophotometer is used to test the absorbance of the sodium linear alkylbenzene sulfonate and methylene blue reactants at a wavelength of 652nm. It is also applicable to a series of anionic surfactants such as sodium alkyl sulfonate and sodium sulfate of fatty alcohol. Sodium linear alkylbenzene sulfonate is dissolved in a methylene blue solution, and a specific chemical reaction occurs, resulting in a change in color for subsequent quantitative analysis. Spectrophotometer test: Use a spectrophotometer to measure the absorbance at a specific wavelength (such as 652nm), and determine the concentration of the substance in the solution by measuring the absorption of the solution to light of a specific wavelength. This method is not only applicable to sodium linear alkylbenzene sulfonate, but also to other types of anionic surfactants, such as sodium alkyl sulfonate, sodium sulfate of fatty alcohol, etc.

[0097] Separation and measurement of nonionic surfactants: Take out an appropriate amount of the eluate in step S41 and concentrate it. After concentration, perform infrared testing to analyze the effective functional groups. Preliminary determination is that it is a nonionic surfactant. When using high performance liquid chromatography, the test conditions are: Merck LiChrosorb NH2, 4mmX250nm, mobile phase ethane / THF, injection volume 10uL, column temperature 40°C, evaporative light scattering detector. Through the test spectrum, ethoxylated compounds can be accurately tested, which can prove that nonionic surfactants exist. By confirming the elution time and elution position of fatty alcohols, it can be determined that it is fatty alcohol polyoxyethylene ether according to the elution position. The fatty alcohol polyoxyethylene ether is distinguished by the category of fatty alcohols, such as carbon-14 fatty alcohols, carbon-12 fatty alcohols, etc., which is also applicable to a series of nonionic surfactants such as alkylphenol polyoxyethylene ethers.

[0098] In step S5, if one or more surfactants are measured after separation, it is determined to be recycled material from the drum material of the washing machine; if no surfactant is measured after separation, it is determined not to be recycled material from the drum material of the washing machine, and the judgment process ends.

[0099] In summary, the method for determining whether the drum material in a washing machine is recycled material provided by the present invention detects whether it contains oily compounds. If no oily compounds are detected, a preliminary judgment is made through one extraction whether the recycled material contains a surfactant, thereby quickly determining whether it is the recycled drum material in the washing machine, saving time and resources, and being particularly beneficial for the processing of large quantities of samples; through subsequent separation and detection steps, the type and content of the surfactant can be further confirmed, thereby improving the accuracy of the judgment, reducing the possibility of misjudgment, and ensuring the reliability of the final judgment; the present invention provides a step-by-step judgment method, which allows unnecessary further analysis to be avoided when only one surfactant is found in the initial extraction, thereby saving analysis costs, and only performing more complex separations and detections when necessary, reducing waste of resources; further, it can also accurately determine the source of the recycled material, thereby providing a basis for effectively controlling the materials containing harmful substances entering the recycling process, and contributing to environmental protection and sustainable utilization of resources.

[0100] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for determining whether the drum material in a washing machine is recycled material, characterized in that: include: Pre-processing to obtain recycled material and crushed material; The recycled material and the grease residue extractant are fully contacted for extraction. If grease compounds are detected, it is determined that the recycled material is not the recycled material of the drum material of the washing machine, and the determination process ends; If no oily compound is detected, the recycled material and the crushed material are fully contacted with the extraction solvent for extraction; If one type of surfactant is extracted, it is judged to be recycled material from the drum of the washing machine. If two or more different types of surfactants are extracted or no surfactant is extracted, separate measurements are performed; If one or more surfactants are measured after separation, it is judged to be recycled material from the drum material of the washing machine. If no surfactant is measured after separation, it is determined not to be recycled material from the drum material of the washing machine.

2. The method for determining whether the drum material in a washing machine is recycled material according to claim 1, characterized in that: The pretreatment process includes crushing, cleaning, drying and removing impurities from the recycled material to obtain the recycled material crushed material.

3. The method for determining whether the drum material in a washing machine is recycled material according to claim 1, characterized in that: The extraction solvent includes ethanol and isopropanol, and the mass ratio of the ethanol to isopropanol is 80:20 to 85:

15.

4. The method for determining whether the drum material in a washing machine is recycled material according to claim 1, characterized in that: The extraction solvent includes ethanol, isopropanol and methanol; the mass ratio of ethanol, isopropanol and methanol is 80:15:5 to 75:20:

5.

5. The method for determining whether the drum material in a washing machine is recycled material according to claim 1, characterized in that: The process of fully contacting the recycled material and the extraction solvent for extraction comprises: A plurality of samples of the recycled material and crushed material are selected, and respectively subjected to Soxhlet extraction, the extraction solvent is heated to boiling, and the plurality of extracts are collected and concentrated together for infrared testing, and the types of surfactants present are obtained based on the infrared spectrum obtained by the infrared test.

6. The method for determining whether the drum material in a washing machine is recycled material as claimed in claim 5, characterized in that: The heating temperature range during the extraction process is 65 to 85°C, and the extraction time is 24h to 48h.

7. The method for determining whether the drum material in a washing machine is recycled material as claimed in claim 5, characterized in that: The surfactant is an anionic surfactant, a cationic surfactant, an amphoteric surfactant or a combination of one or more nonionic surfactants.

8. The method for determining whether the drum material in a washing machine is recycled material as claimed in claim 1, characterized in that: Select multiple samples and fully contact them with the grease residue extraction agent for extraction, combine the multiple filtered extracts for concentration, and take the concentrated solution for infrared spectroscopy analysis or gas chromatography-mass spectrometry analysis. If the characteristic peaks of grease compounds are detected, it proves that the samples are not recycled materials from the washing machine drum.

9. The method for determining whether the drum material in a washing machine is recycled material according to claim 8, characterized in that: The grease residue extracting agent includes chloroform or carbon tetrachloride.

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