A PCR material stacking barrel and its preparation process

Abstract

This application relates to the technical field of plastic recycled products, and specifically discloses a stacking bucket made of PCR materials and its preparation process. The stacking bucket made of PCR materials is made from recycled plastic particles, which are obtained by successively subjecting waste plastics to rough washing, crushing, fine washing and drying, then mixing with additives and performing melt granulation. During the fine washing process, the detergent is mixed with the waste plastics that have been roughly washed and crushed and then centrifugally washed. The components of the detergent include an anionic surfactant, a builder, deionized water and a swelling agent. In this application, the particles of the builder are used for scouring and abrasion, and the swelling agent is used to increase the deformation of the waste plastics, accelerating the shedding of the stain layer. The builder can also reduce the adsorption of calcium and magnesium ions in the stain layer on the anionic surfactant, improving the washing effect of the detergent on the waste plastics.

Description

Technical Field

[0001] This application relates to the technical field of plastic recycled products, and more specifically, it relates to a PCR material stacking barrel and its preparation process. Background Art

[0002] Plastic is the most widely used polymer material. At present, the ways to deal with waste plastics include incineration, landfill, and recycling. Among them, the incineration method for dealing with waste plastics has limited application prospects due to secondary pollution, while the landfill method will occupy a large amount of land resources. The recycling method is to purify waste plastics and then make them into recycled plastic products (also called PCR products), which has certain positive significance for solving the problem of plastic waste.

[0003] There is a kind of PCR material stacking barrel in the related technology, which is prepared according to the following method: (1) Mix an anionic surfactant and deionized water to obtain a detergent; (2) Mix the water for rough washing with waste plastics, let it stand and then carry out solid-liquid separation to obtain roughly washed plastics; (3) Crush the roughly washed plastics obtained in step (2), then mix the crushed product with the detergent, and then carry out fine washing under centrifugation conditions. After the fine washing is completed, carry out solid-liquid separation. The separated solid is dried and then mixed with additives to obtain granulation raw materials; (4) Carry out melt granulation on the granulation raw materials to obtain recycled plastic particles, carry out melt extrusion on the recycled plastic particles to obtain a blank mold, and carry out blow molding and cooling and shaping on the blank mold to obtain a PCR material stacking barrel.

[0004] In view of the above related technology, the inventor believes that although the waste plastics that have been cleaned and crushed are recycled in the related technology, if the waste plastics have come into contact with landfill leachate and soil before recycling, the soil will absorb the landfill leachate and form a stain layer on the surface of the waste plastics. Landfill leachate usually contains a certain amount of calcium and magnesium ions, and these calcium and magnesium ions will be stored in the soil particles in the stain layer. During the fine washing process, the anionic surfactant in the detergent is easily adsorbed by the calcium and magnesium ions in the stain layer, resulting in a decline in the washing effect of the detergent and being unfavorable for improving the product quality of the PCR material stacking barrel. Summary of the Invention

[0005] For waste plastics that have come into contact with landfill leachate and soil before recycling, the soil around the waste plastics will absorb the landfill leachate and form a stain layer on the surface of the waste plastics. During the fine washing process, the anionic surfactant in the detergent is easily adsorbed by the calcium and magnesium ions in the stain layer, resulting in a decline in the washing effect of the detergent and being unfavorable for improving the product quality of the PCR material stacking barrel. To improve this defect, this application provides a PCR material stacking barrel and its preparation process.

[0006] In a first aspect, the present application provides a stacking bucket for PCR materials, adopting the following technical solutions:

[0007] A stacking bucket for PCR materials, which is made of recycled plastic particles. The recycled plastic particles are obtained by sequentially subjecting waste plastics to rough washing, crushing, fine washing, and drying, and then mixing with an auxiliary agent and performing melt granulation. In the fine washing process, the detergent is first mixed with the waste plastics that have been roughly washed and crushed, then centrifugal washing is carried out, and finally water washing is carried out. The detergent comprises the following components in parts by weight: 24 - 28 parts of an anionic surfactant, 18 - 22 parts of a builder, 240 - 280 parts of deionized water, and 26 - 30 parts of a swelling agent. The builder is an inorganic abrasive grafted with carboxyl groups on its surface.

[0008] By adopting the above technical solutions, in the detergent of the present application, in addition to the anionic surfactant, a builder is added, and the inorganic abrasive enables the builder to have a certain mechanical strength. When the detergent is mixed with the waste plastics that have been roughly washed and centrifugal washing is carried out, the swelling agent first causes the waste plastics to swell, weakening the binding force between the waste plastics and the stain layer. When the builder washes the surface of the waste plastics along with the water flow, the mechanical abrasion effect of the builder itself can wear the stain layer, accelerating the shedding of the stain layer. The carboxyl groups on the surface of the builder and the anionic surfactant can form a competitive adsorption relationship and combine with the shed soil particles and calcium and magnesium ions, thereby reducing the adsorption of calcium and magnesium ions in the stain layer on the anionic surfactant, improving the washing effect of the detergent on the waste plastics, and contributing to improving the product quality of the stacking bucket for PCR materials.

[0009] Preferably, the detergent comprises the following components in parts by weight: 25 - 27 parts of an anionic surfactant, 19 - 21 parts of a builder, 250 - 270 parts of a washing liquid, and 27 - 29 parts of a suspending agent.

[0010] By adopting the above technical solutions, the formula of the detergent is optimized, which helps to improve the washing effect of the detergent on the waste plastics.

[0011] Preferably, the builder is prepared according to the following method:

[0012] (1) Mix a silane coupling agent, water, and ethanol to obtain a modified liquid. In this step, the molecule of the silane coupling agent contains vinyl.

[0013] (2) Grind the inorganic abrasive and then mix it with the modified liquid to obtain a first reaction liquid. Let the first reaction liquid stand for 60 - 80 minutes and then dry it to obtain a silanized abrasive.

[0014] (3) Mix the silanized abrasive, unsaturated monomer, water, and initiator to obtain a second reaction solution. Heat the second reaction solution for 40 - 60 min and then evaporate the second reaction solution to dryness to obtain a carboxylated abrasive. Wash the carboxylated abrasive and then dry it to obtain a detergent builder. In this step, the molecule of the unsaturated monomer contains a carboxyl group.

[0015] By adopting the above technical solution, in this application, the inorganic abrasive is first modified with a modification solution containing a silane coupling agent. The silane coupling agent can graft an organic chain segment containing a vinyl group on the surface of the inorganic abrasive to obtain a silanized abrasive. The vinyl group on the surface of the silanized abrasive polymerizes with the unsaturated monomer under the action of the initiator, thereby converting the organic chain segment containing a vinyl group into an organic chain segment containing a carboxyl group, and obtaining a carboxylated abrasive. The carboxylated abrasive can be obtained as a detergent builder after drying.

[0016] Preferably, the inorganic abrasive includes quartz sand and zeolite particles.

[0017] By adopting the above technical solution, during the co-grinding process of quartz sand and zeolite particles, quartz sand will cause the zeolite particles to break fully into smaller particles. After being ground by quartz sand, the particle size of the zeolite particles decreases and the specific surface area increases. Therefore, more silane coupling agents can be grafted, and finally, after grafting with the unsaturated monomer, the carboxyl content in the detergent builder increases, which helps to improve the adsorption effect of the detergent builder on calcium and magnesium ions.

[0018] Preferably, in step (2) of preparing the detergent builder, a surface roughening agent is also added during the grinding of the inorganic abrasive. The components of the surface roughening agent include serpentine particles and calcium hydroxide.

[0019] By adopting the above technical solution, during the grinding process, the serpentine particles will undergo interlayer cleavage and chemical bond breakage, and release free water. After the free water dissolves calcium hydroxide, it will erode the surfaces of the quartz sand and zeolite particles, and form calcium silicate on the surfaces of the quartz sand and zeolite particles, thereby increasing the roughness of the detergent builder, which helps to improve the scouring and abrasion effects of the particles of the detergent builder on the stain layer on the surface of waste plastics. In addition, calcium hydroxide can also increase the porosity of the zeolite particles and improve the adsorption effect of the zeolite particles on calcium and magnesium ions.

[0020] Preferably, in step (2) of preparing the detergent builder, fly ash is also mixed with the inorganic abrasive.

[0021] By adopting the above technical solution, after the magnesium hydroxy silicate releases free water, the free water dissolves calcium hydroxide, and the calcium hydroxide undergoes a pozzolanic reaction with fly ash, which activates the hydration activity of fly ash. The hydration of fly ash consumes water, which helps to reduce the accumulation of water. At the same time, the dissociation products of serpentine also play a lubricating role, reducing the possibility of agglomeration of inorganic abrasives during grinding. The hydration products of fly ash can adhere to the surfaces of quartz sand and zeolite particles together with calcium silicate, and form a silicate adhesion zone after curing, which helps to increase the roughness of the washing aid and improve the scouring and abrasion effects of the particles of the washing aid on the stain layer on the surface of waste plastics.

[0022] Preferably, in step (3) of preparing the washing aid, the carboxylated abrasive is washed in the following manner: after soaking the carboxylated abrasive with a sodium tripolyphosphate solution, the carboxylated abrasive is filtered and recovered, and then the recovered carboxylated abrasive is washed with deionized water.

[0023] By adopting the above technical solution, sodium tripolyphosphate can complex calcium ions in the silicate adhesion zone, causing the calcium ions to dissolve out, reducing the calcium ion content in the washing aid, and being beneficial to the adsorption of calcium ions by the washing aid.

[0024] Preferably, the initiator is selected as persulfate.

[0025] By adopting the above technical solution, persulfate can promote the breaking and regeneration of silicon-oxygen bonds, repair the structural defects in the washing aid while initiating polymerization, reduce the possibility of the particles of the washing aid breaking during centrifugal washing, and improve the washing effect of the detergent.

[0026] Preferably, the swelling agent is selected as dibutyl phthalate.

[0027] By adopting the above technical solution, in the presence of an anionic surfactant, dibutyl phthalate can swell polystyrene plastics, which helps to clean polystyrene plastics.

[0028] In the second aspect, the present application provides a preparation process for a PCR material stacking barrel, adopting the following technical solution.

[0029] A preparation process for a PCR material stacking barrel includes the following steps:

[0030] (1) Coarse washing and crushing: Mix an anionic surfactant, a washing aid, deionized water, and a swelling agent to obtain a detergent; mix the water for coarse washing with waste plastics, and after standing, perform solid-liquid separation to obtain coarsely washed plastics;

[0031] (2) Fine washing and premixing: The roughly washed plastics obtained in step (1) are crushed, and then the crushed product is mixed with a detergent, followed by washing under centrifugal conditions. After the washing is completed, the floating plastic fragments are fished out, followed by another water wash. After the water wash is completed, solid-liquid separation is carried out. The separated solid is dried and then mixed with an auxiliary agent to obtain granulation raw materials;

[0032] (3) Molding: The granulation raw materials are melt granulated to obtain recycled plastic particles. The recycled plastic particles are melt extruded to obtain a blank mold, and the blank mold is blow molded and cooled and shaped to obtain a PCR material stacking barrel.

[0033] By adopting the above technical solutions, the method of the present application sequentially performs rough washing, crushing, fine washing and drying on waste plastics, and then blends the obtained plastic solids with an auxiliary agent and granulates them to obtain recycled plastic particles. Then, using the recycled plastic particles as raw materials, a PCR material stacking barrel is prepared, realizing the recycling of waste plastics.

[0034] In summary, the present application has the following beneficial effects:

[0035] 1. Under centrifugal conditions, the particles of the washing aid in the present application scour and abrade the stain layer on the surface of the waste plastics after rough washing, and the swelling agent increases the deformation of the waste plastics, accelerating the shedding of the stain layer. The washing aid can also form a competitive adsorption relationship with the anionic surfactant, reducing the adsorption of calcium and magnesium ions in the stain layer on the anionic surfactant, improving the washing effect of the detergent on the waste plastics, and being beneficial to improving the product quality of the PCR material stacking barrel.

[0036] 2. In step (2) of preparing the washing aid in the present application, the hydration of fly ash consumes water when it is mixed with the inorganic abrasive, which helps to reduce the accumulation of water. At the same time, the dissociation products of serpentine also play a lubricating role, reducing the possibility of agglomeration of the inorganic abrasive during grinding. The hydrated products of fly ash form a silicate attachment area after solidification, which helps to increase the roughness of the washing aid and improve the scouring and abrasion effect of the particles of the washing aid on the stain layer on the surface of the waste plastics.

[0037] 3. The method of the present application sequentially performs rough washing, crushing, fine washing and drying on waste plastics, and then blends the obtained plastic solids with an auxiliary agent and performs melt granulation to obtain recycled plastic particles. Then, using the recycled plastic particles as raw materials, after melt extrusion and blow molding, and after cooling and shaping, a PCR material stacking barrel is obtained, realizing the recycling of waste plastics. Specific embodiments

[0038] The present application will be further described in detail below with reference to examples, preparation examples and comparative examples. The raw materials involved in the present application can all be obtained commercially.

[0039] Preparation Example of Builder

[0040] Taking Preparation Example 1 as an example, it is described as follows.

[0041] Preparation Example 1

[0042] In this preparation example, the builder is prepared according to the following method:

[0043] (1) Mix a silane coupling agent, water, and ethanol according to a weight ratio of 2:4:5 to obtain a modified liquid; in this step, the silane coupling agent is vinyltriethoxysilane;

[0044] (2) Grind the inorganic abrasive and then mix it with the modified liquid to obtain a first reaction liquid. Let the first reaction liquid stand for 75 min and then dry it at 105 °C to obtain a silanized abrasive; in this step, the inorganic abrasive is quartz sand with an average particle size of 0.75 mm;

[0045] (3) Mix the silanized abrasive, unsaturated monomer, water, and initiator according to a weight ratio of 35:12:60:1 to obtain a second reaction liquid. Heat the second reaction liquid at 80 °C for 45 min and then evaporate the second reaction liquid to dryness to obtain a carboxylated abrasive. Wash the carboxylated abrasive and then dry it at 105 °C to obtain the builder; in this step, the unsaturated monomer is acrylic acid and the initiator is azobisisobutyronitrile; in this step, when washing the carboxylated abrasive, the operation is as follows: soak the carboxylated abrasive in deionized water for 1 h and then filter and recover the carboxylated abrasive.

[0046] Preparation Example 2

[0047] The difference between this preparation example and Preparation Example 1 is that the inorganic abrasive is composed of quartz sand and zeolite particles mixed according to a weight ratio of 4:1.

[0048] Preparation Example 3

[0049] The difference between this preparation example and Preparation Example 2 is that in step (2) of preparing the builder, when grinding the inorganic abrasive, a surface roughening agent equivalent to 20% of the total weight of the inorganic abrasive is also added, and the surface roughening agent is composed of serpentine particles and calcium hydroxide mixed according to a weight ratio of 1:1.

[0050] Preparation Example 4

[0051] The difference between this preparation example and Preparation Example 3 is that in step (2) of preparing the builder, 5% of fly ash equivalent to the total weight of the inorganic abrasive is also mixed with the inorganic abrasive.

[0052] Preparation Example 5

[0053] The difference between this Preparation Example and Preparation Example 4 lies in that in step (3) of preparing the builder, the carboxylated abrasive is washed in the following manner: after soaking the carboxylated abrasive in a sodium tripolyphosphate solution with a mass concentration of 1% for 1 h, the carboxylated abrasive is filtered and recovered, and then the recovered carboxylated abrasive is washed with deionized water.

[0054] Preparation Example 6

[0055] The difference between this Preparation Example and Preparation Example 4 is that sodium persulfate is used as the initiator.

[0056] Example

[0057] Examples 1 - 5

[0058] The following takes Example 1 as an illustration.

[0059] Example 1

[0060] In this example, the detergent comprises the following components by weight: 24 kg of an anionic surfactant, 18 kg of the builder of Preparation Example 1, 240 kg of deionized water, 26 kg of a swelling agent. The anionic surfactant is sodium dodecyl sulfate, and the swelling agent is dibutyl phthalate. The waste plastic is waste polystyrene sheets taken from a waste recycling station. After the waste plastic sample is soaked and scrubbed to remove the stain layer, it is observed that soil particles fall off on the surface, and calcium ions and magnesium ions are detected in the residual liquid after scrubbing.

[0061] In this example, the PCR material stacking barrel is prepared according to the following steps:

[0062] (1) Coarse washing and crushing: Mix the anionic surfactant, the builder, deionized water, and the swelling agent to obtain a detergent; mix the water for coarse washing and the waste plastic according to a weight ratio of 4:1, then let it stand for 1 h. After standing, perform solid-liquid separation to obtain coarsely washed plastic. In this step, the water for coarse washing is industrial water;

[0063] (2) Fine washing and premixing: Crush the coarsely washed plastic obtained in step (1) to an average particle size of 2.36 mm, then mix the crushed product with the detergent according to a weight ratio of 1:4, and perform centrifugal fine washing at a rate of 500 r / min for 15 min. After fine washing, fish out the suspended plastic fragments, then perform a water wash on the fished-out plastic fragments once again. After the water wash, filter and recover the plastic fragments and dry them at 80 °C for 8 h. Then mix the plastic fragments with the auxiliary agent according to a weight ratio of 11.4:1 to obtain the granulation raw material. In this step, the auxiliary agent is composed of titanium dioxide, silicon carbide fiber, methyltriethoxysilane, magnesium stearate, and stearoylbenzoylmethane mixed according to a weight ratio of 4:1:0.2:0.4:0.7;

[0064] (3) Molding: The granulated raw materials are melt granulated at 180 °C to obtain recycled plastic particles. The recycled plastic particles are melt extruded at 170 °C to obtain a blank mold. The blank mold is blow molded at 130 °C and then cooled and shaped to obtain a PCR material stacking bucket.

[0065] As shown in Table 1, the main difference between Examples 1-5 lies in the different raw material ratios of the detergent.

[0066] Table 1

[0067]

[0068] Examples 6-10

[0069] As shown in Table 2, the difference between Example 3 and Examples 6-10 is that the preparation examples of the builder are different.

[0070] Sample Example 3 Example 6 Example 7 Example 8 Example 9 Example 10 Preparation Example of Builders Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 Preparation Example 5 Preparation Example 6

[0071] Comparative Example

[0072] Comparative Example 1

[0073] In this comparative example, the detergent is composed of 26 kg of anionic surfactant and 260 kg of water, and the source of the waste plastic is the same as that in Example 1.

[0074] This comparative example provides a PCR material stacking bucket, which is prepared according to the following steps:

[0075] (1) Coarse washing and crushing: Mix the anionic surfactant and deionized water to obtain a detergent; in this step, the anionic surfactant is sodium dodecyl sulfate; mix the water for coarse washing and the waste plastic in a weight ratio of 4:1, then let it stand for 1 h, and after standing, perform solid-liquid separation to obtain coarsely washed plastic; in this step, the water for coarse washing is industrial water;

[0076] (2) Fine washing and premixing: Crush the coarsely washed plastic obtained in step (1) to an average particle size of 2.36 mm, then mix the crushed product with the detergent in a weight ratio of 1:4, and perform centrifugal fine washing at a rate of 500 r / min for 15 min. After fine washing, fish out the suspended plastic fragments, then wash the fished-out plastic fragments once more. After washing, filter and recycle the plastic fragments and dry them at 80 °C for 8 h. Then mix the plastic fragments with the additive in a weight ratio of 11.4:1 to obtain granulated raw materials; in this step, the additive is composed of titanium dioxide, silicon carbide fiber, methyltriethoxysilane, magnesium stearate, and stearoyl benzoyl methane mixed in a weight ratio of 4:1:0.2:0.4:0.7;

[0077] (3) Molding: The granulated raw materials are melt granulated at 180 °C to obtain recycled plastic particles. The recycled plastic particles are melt extruded at 170 °C to obtain a blank mold. The blank mold is blow molded at 130 °C and then cooled and shaped to obtain a PCR material stacking barrel.

[0078] Comparative Example 2

[0079] The difference between this comparative example and Example 3 is that the components of the detergent do not include a swelling agent.

[0080] Comparative Example 3

[0081] The difference between this comparative example and Example 3 is that the components of the detergent do not include an anionic surfactant.

[0082] Comparative Example 4

[0083] The difference between this comparative example and Example 3 is that the components of the detergent do not include a builder.

[0084] Performance detection test method Sample selection: Take 100 g of the fragments of the roughly washed plastic (counted by the weight after drying) as Sample A, and take 100 g of the plastic fragments fished out after fine washing (counted by the weight after drying) as Sample B.

[0085] Performance characterization:

[0086] Use a ball mill to crush the dried sample to an average particle size of 0.5 μm, then mix the crushed product with 400 g of deionized water, and then titrate the total content C (unit: mg / L) of calcium and magnesium ions in the mixed solution with an EDTA standard solution.

[0087] Detect the C values of Sample A and Sample B respectively, and then calculate the ratio of the C value of Sample B to the corresponding C value of Sample A in each example / comparative example, denoted as the calcium and magnesium residue rate, and the result is expressed as a percentage, as shown in Table 3.

[0088] Sample Calcium and Magnesium Residual Rate / % Sample Calcium and Magnesium Residual Rate / % Example 1 16.4 Example 8 10.8 Example 2 15.7 Example 9 10.3 Example 3 15.1 Example 10 10.1 Example 4 15.3 Comparative Example 1 49.7 Example 5 15.9 Comparative Example 2 23.6 Example 6 14.2 Comparative Example 3 78.9 Example 7 13.4 Comparative Example 4 37.8

[0089] Combined with Examples 1-5 and Comparative Example 1 and combined with Table 3, it can be seen that the calcium and magnesium residue rates measured in Examples 1-5 are all less than that of Comparative Example 1, indicating that in this application, the particles of the builder scour and abrade the stain layer on the surface of the waste plastic after rough washing, and the swelling agent increases the deformation of the waste plastic, accelerating the shedding of the stain layer. At the same time, since the builder can form a competitive adsorption relationship with the anionic surfactant, the adsorption of calcium and magnesium ions in the stain layer on the anionic surfactant is reduced, improving the washing effect of the detergent on the waste plastic.

[0090] Combining Example 3 and Comparative Example 2 and referring to Table 3, it can be seen that the calcium and magnesium residue rate measured in Example 3 is less than that in Comparative Example 2, indicating that when the detergent does not contain a swelling agent, the binding force between the waste plastic and the stain layer is relatively strong, and the stain layer is not easily washed off, resulting in poor washing effect of the detergent on the waste plastic.

[0091] Combining Example 3 and Comparative Example 3 and referring to Table 3, it can be seen that the calcium and magnesium residue rate measured in Example 3 is less than that in Comparative Example 3, indicating that when the detergent does not contain an anionic surfactant, it is difficult for the mechanical scouring effect of the builder alone to achieve sufficient removal effect on the stain layer on the surface of the waste plastic.

[0092] Combining Example 3 and Comparative Example 4 and referring to Table 3, it can be seen that the calcium and magnesium residue rate measured in Example 3 is less than that in Comparative Example 4, indicating that when the detergent does not contain a builder, the stain layer on the surface of the waste plastic is not easily shed, and the anionic surfactant is strongly adsorbed by calcium ions and magnesium ions, resulting in poor washing effect of the detergent on the waste plastic.

[0093] Combining Example 3 and Example 6 and referring to Table 3, it can be seen that the calcium and magnesium residue rate measured in Example 6 is less than that in Example 3, indicating that after the zeolite particles are ground by quartz sand, the particle size decreases and the specific surface area increases. Therefore, more silane coupling agents can undergo grafting, and finally the carboxyl group content in the builder increases after grafting with unsaturated monomers, improving the adsorption effect of the builder on calcium and magnesium ions.

[0094] Combining Example 6 and Example 7 and referring to Table 3, it can be seen that the calcium and magnesium residue rate measured in Example 7 is less than that in Example 6, indicating that after the free water released by the serpentine particles dissolves calcium hydroxide, the calcium hydroxide improves the roughness of the builder, enhancing the scouring and abrasion effects of the builder particles on the stain layer on the surface of the waste plastic. At the same time, calcium hydroxide also increases the porosity of the zeolite particles, improving the adsorption effect of the zeolite particles on calcium and magnesium ions.

[0095] Combining Example 7, Example 8 and referring to Table 3, it can be seen that the calcium and magnesium residue rate measured in Example 8 is less than that in Example 7, indicating that the hydration products of fly ash and calcium silicate are attached to the surface of quartz sand and zeolite particles together, and form a silicate attachment area after curing, increasing the roughness of the builder and improving the scouring and abrasion effects of the builder particles on the stain layer on the surface of the waste plastic.

[0096] Combining Example 8, Example 9 and referring to Table 3, it can be seen that the calcium and magnesium residue rate measured in Example 9 is less than that in Example 8, indicating that sodium tripolyphosphate can complex calcium ions in the silicate attachment area, causing the calcium ions to dissolve out, reducing the calcium ion reserve in the builder, improving the adsorption effect of the builder on calcium ions, and inhibiting the adsorption of calcium ions on sodium dodecyl sulfate.

[0097] Combined with Example 9 and Example 10 and in conjunction with Table 3, it can be seen that the calcium and magnesium residue rate measured in Example 10 is less than that in Example 9, indicating that persulfate can promote the breakage and regeneration of silicon-oxygen bonds, repair the structural defects in the builder while initiating polymerization, reduce the possibility of the builder particles breaking during centrifugal washing, and improve the washing effect of the detergent.

[0098] This specific embodiment is only an interpretation of the present application and is not a limitation thereof. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A preparation process of a stacking bucket for PCR materials, characterized in that, It includes the following steps: (1) Coarse washing and crushing: Mix an anionic surfactant, a builder, deionized water, and a swelling agent to obtain a detergent; mix the water for coarse washing with waste plastics, perform solid-liquid separation after standing, and obtain coarsely washed plastics; the detergent includes the following components in parts by weight: 24-28 parts of an anionic surfactant, 18-22 parts of a builder, 240-280 parts of deionized water, and 26-30 parts of a swelling agent; the builder is prepared according to the following method: S1. Mix a silane coupling agent, water, and ethanol to obtain a modified liquid; the molecule of the silane coupling agent contains a vinyl group; S2. Grind the inorganic abrasive and then mix it with the modified liquid to obtain a first reaction liquid, dry the first reaction liquid after standing for 60-80 min to obtain a silanized abrasive; the inorganic abrasive includes quartz sand and zeolite particles; S3. Mix the silanized abrasive, an unsaturated monomer, water, and an initiator to obtain a second reaction liquid, heat the second reaction liquid for 40-60 min and then evaporate the second reaction liquid to dryness to obtain a carboxylated abrasive, wash the carboxylated abrasive and then dry it to obtain a builder; the molecule of the unsaturated monomer contains a carboxyl group. (2) Fine washing and premixing: Crush the coarsely washed plastics obtained in step (1), then mix the crushed product with the detergent, and then wash it under centrifugation conditions. After the washing is completed, fish out the floating plastic fragments, perform another water wash, and perform solid-liquid separation after the water wash is completed. The separated solid is dried and then mixed with an auxiliary agent to obtain a granulation raw material. (3) Molding: Perform melt granulation on the granulation raw material to obtain recycled plastic particles, perform melt extrusion on the recycled plastic particles to obtain a blank mold, and perform blow molding and cooling and shaping on the blank mold to obtain a PCR material stacking barrel.

2. The preparation process of a stacking bucket for PCR materials according to claim 1, characterized in that, In step S2 of preparing the builder, a surface roughening agent is also added during the grinding of the inorganic abrasive, and the components of the surface roughening agent include serpentine particles and calcium hydroxide.

3. The preparation process of a stacking bucket for PCR materials according to claim 2, characterized in that, In step S2 of preparing the builder, fly ash is also mixed with the inorganic abrasive.

4. The preparation process of a stacking bucket for PCR materials according to claim 3, characterized in that, In step S3 of preparing the builder, the carboxylated abrasive is washed in the following manner: Soak the carboxylated abrasive in a sodium tripolyphosphate solution, filter and recover the carboxylated abrasive, and then wash the recovered carboxylated abrasive with deionized water.

5. The preparation process of a stacking bucket for PCR materials according to claim 1, characterized in that, The initiator is selected as a persulfate.

6. The preparation process of a stacking bucket for PCR materials according to claim 1, characterized in that, The swelling agent is selected as dibutyl phthalate.

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