Method for separating and recycling bottle cap and bottle body of PP plastic bottle

Abstract

The invention discloses a method for separating and recycling bottle caps and bottle bodies of PP plastic bottles, and belongs to the field of plastics. The polypropylene PP plastic bottle cap mainly comprises the following components in parts by weight: 50-60 parts of polypropylene, 30-40 parts of calcium carbonate, 8-15 parts of EPDM, 0.1-0.2 part of erucyl amide, 0.5-3 parts of quaternary ammonium salt, 0.1-0.5 part of an antioxidant and 2-5 parts of a stabilizer. According to the invention, the polypropylene is used as a main material, the calcium carbonate is used as an auxiliary material, and the polypropylene and calcium carbonate composite material can be recycled, so that the plastic bottle cap is environment-friendly and pollution-free; the impact of waste on the environment is reduced, the material mass is lighter, subsequent operation is facilitated, the polypropylene and calcium carbonate composite material is low in manufacturing cost and has high market competitiveness, the mechanical property of a plastic product can be remarkably improved by adding calcium carbonate, and the tensile strength, bending strength and impact toughness of the plastic product are improved.

Description

Technical Field

[0001] The invention relates to the technical field of plastics, in particular to a method for separating a polypropylene (PP) plastic bottle cap from a bottle body for recycling. Background Art

[0002] Plastic bottle caps are devices used to close or seal containers, usually made of plastic materials. Plastic bottle caps are divided into PP, PE, and other types according to the material. PP is a non-toxic, odorless, tasteless milky white high-crystalline polymer with a density of 0.90-0.91g / cm 3 PE material is light and transparent, and is moisture-proof, anti-oxidation, acid-resistant, alkali-resistant, and has general air tightness. It has good ductility and is not easy to break, and has excellent heat sealing properties. PE film is light and transparent, and meets the sanitation standards for food packaging. According to its characteristics, PP plastic bottle caps have good heat resistance and strong resistance to heat deformation. PP plastic is one of the lightest varieties of all plastics. Its water absorption rate is only 0.01%, and its molecular weight is between 80,000 and 150,000. According to its characteristics, PE plastic bottle caps have poor heat resistance, are easy to deform, and have high flexibility. From the existing technology, common polypropylene bottle caps have poor resistance to low temperatures, and when polypropylene is recycled, it is usually washed and melted before being used directly for accommodation, which greatly increases the content of debris in the plastic and is prone to breeding bacteria. To this end, we provide a method for separating and recycling polypropylene PP plastic bottle caps from bottle bodies. Summary of the invention

[0003] The purpose of the present invention is to provide a method for separating and recycling the polypropylene (PP) plastic bottle cap and the bottle body in order to solve the above technical problems. The method has the advantages of being recyclable, reducing the impact of waste on the environment, significantly improving impact strength and low-temperature performance, and being effective against a variety of microorganisms, including bacteria, viruses and fungi, and having a broad-spectrum bactericidal effect.

[0004] To achieve this purpose, the present invention provides a method for separating and recycling a polypropylene PP plastic bottle cap from a bottle body, which adopts the following technical embodiments:

[0005] A polypropylene (PP) plastic bottle cap, which is mainly made of polypropylene (PP): the components of the polypropylene (PP) plastic bottle cap mainly include: polypropylene, 50-60 parts, calcium carbonate, 30-40 parts, EPDM, 8-15 parts, erucamide, 0.1-0.2 parts, quaternary ammonium salt, 0.5-3 parts, antioxidant, 0.1-0.5 parts, stabilizer, 2-5 parts.

[0006] Preferably, the antioxidant is any one of pomegranate seed extract PSE, grape seed extract GSE, and seabuckthorn seed extract SSE, and the stabilizer is zinc stearate, with a chemical formula of C36H70O4Zn.

[0007] Preferably, the method for preparing a polypropylene PP plastic bottle cap comprises the following steps:

[0008] S1: Raw material preparation: polypropylene and calcium carbonate are crushed and mixed separately to obtain a base material;

[0009] S2: heating, stirring and mixing the base material until the base material is in a molten state;

[0010] S3: adding EPDM, erucamide, quaternary ammonium salt, antioxidant and stabilizer into the molten base material, and continuing heating and stirring to obtain a mixture;

[0011] S4: injecting the molten mixture into a bottle cap mold through an injection molding machine, and forming the shape of the bottle cap after cooling;

[0012] S5: Trim and inspect the formed bottle caps.

[0013] Preferably, in the above step S2, the heating temperature is maintained at 175-190°C.

[0014] Preferably, in the above step S3, auxiliary agents are added, and the auxiliary agents include EPDM, erucamide, quaternary ammonium salt, antioxidant, and stabilizer, wherein EPDM is first added as a plasticizer, and then erucamide, quaternary ammonium salt, antioxidant, and stabilizer are added.

[0015] Preferably, in the above step S4, the mold temperature of the injection molding machine is set at 45-75°C, the injection pressure range is 80-140MPa, the holding pressure is about 30%-60% of the injection pressure, and the linear speed of the high screw is 0.9m / s.

[0016] A method for separating a polypropylene (PP) plastic bottle cap from a bottle body for recycling and reuse, the recycling and reuse method comprising the following steps:

[0017] S6: Collect waste polypropylene plastic bottle caps and bottles and sort them by color and type;

[0018] S7: repeatedly washing the sorted waste polypropylene plastics to remove dirt and impurities on the surface;

[0019] S8: The cleaned polypropylene plastic is fed into an extruder for melting. During the melting process, the polypropylene plastic is reheated and plasticized;

[0020] S9: Cooling the waste after plasticization, grinding and cutting it after cooling to form polypropylene particles;

[0021] S10: Fill and modify the polypropylene particles according to subsequent applications to improve the performance of the recycled materials;

[0022] S11: Mix the improved waste materials with new materials for application. Mix the waste materials with new materials for use.

[0023] Preferably, in the above step S8, the melting temperature of the extruder is 235°C, the mold temperature is maintained between 50-90°C, the flow channel diameter is 4-7mm, and the needle gate length is 1-1.5mm.

[0024] Preferably, in the above step S9, the polypropylene waste particles are cut into particles with a diameter of 2-5 mm.

[0025] Preferably, in the above step S11, the mixing ratio of waste material to new material does not exceed 1:6.

[0026] The present invention has at least the following beneficial effects:

[0027] In the present invention, the polypropylene PP plastic bottle cap adopts polypropylene as the main material and calcium carbonate as the auxiliary material. The polypropylene and calcium carbonate composite material can be recycled, reducing the impact of waste on the environment. The material is lighter and convenient for subsequent operation. The polypropylene and calcium carbonate composite material has low manufacturing cost and high market competitiveness. The addition of calcium carbonate can significantly improve the mechanical properties of plastic products, increase the tensile strength, bending strength and impact toughness of plastic products, and the addition of calcium carbonate also plays a lubricating role in the plastic melting process, reduces the viscosity of the plastic melt, makes it easier to flow and fill the mold, and improves production efficiency.

[0028] In the present invention, EPDM is used as a plasticizer to improve the toughness of polypropylene plastics, making it less likely to break when subjected to external forces, and significantly improving the impact strength and low-temperature performance.

[0029] In the present invention, adding natural antioxidants, pomegranate seed extract (PSE), grape seed extract (GSE), sea buckthorn seed extract (SSE), can provide safe, non-toxic and non-side-effect antioxidant effects, and the natural antioxidants have no effect on the melting process of polypropylene plastics;

[0030] In the present invention, zinc stearate is added to improve the processing performance and durability of polypropylene plastics, and to increase the service life of repeated recycling and use;

[0031] In the present invention, the addition of erucic acid amide significantly reduces the friction coefficient of the polypropylene material, making the surface of the product smoother and easier to process and handle, and can significantly improve the anti-adhesion property of polypropylene to prevent the products from sticking together during the production process. Erucic acid amide has better thermal stability and is suitable for use in products with higher processing temperatures. Adding erucic acid amide in polypropylene processing can improve the thermoplasticity and heat resistance of the product;

[0032] In the present invention, quaternary ammonium salt is added to the polypropylene plastic. The quaternary ammonium salt is effective against a variety of microorganisms, including bacteria, viruses and fungi, and has a broad-spectrum bactericidal effect, thereby improving the antibacterial effect of the polypropylene plastic and extending the service life of the polypropylene plastic product.

[0033] In the present invention, the polypropylene bottle cap itself has a certain bactericidal effect by adding quaternary ammonium salt, and in the recycling scheme, the content of waste materials in the finished product is reduced to further reduce the possibility of bacterial growth and reduce the probability of users encountering harmful substances.

[0034] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a comparative relationship diagram of the tensile strength test of the polypropylene PP plastic bottle cap prepared in Example 1 of the present invention;

[0036] Figure 2 This is a comparative relationship diagram of the friction temperature test of the polypropylene PP plastic bottle cap prepared in Example 1 of the present invention;

[0037] Figure 3 This is a comparative relationship diagram of the tensile strength test of the polypropylene PP plastic bottle cap prepared in Example 2 of the present invention;

[0038] Figure 4 This is a comparative relationship diagram of the friction temperature test of the polypropylene PP plastic bottle cap prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical embodiments and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] The application principle of the present invention is described in detail below in conjunction with the accompanying drawings.

[0041] A polypropylene (PP) plastic bottle cap, which is mainly made of polypropylene (PP): the components of the polypropylene (PP) plastic bottle cap mainly include: polypropylene, 50-60 parts, calcium carbonate, 30-40 parts, EPDM, 8-15 parts, erucamide, 0.1-0.2 parts, quaternary ammonium salt, 0.5-3 parts, antioxidant, 0.1-0.5 parts, stabilizer, 2-5 parts, wherein the antioxidant is any one of pomegranate seed extract PSE, grape seed extract GSE, and sea buckthorn seed extract SSE, and the stabilizer is zinc stearate, with the chemical formula of C36H70O4Zn.

[0042] The method for preparing a polypropylene (PP) plastic bottle cap comprises the following steps:

[0043] S1: Raw material preparation: polypropylene and calcium carbonate are crushed and mixed separately to obtain a base material;

[0044] S2: heating, stirring and mixing the base material until the base material is in a molten state;

[0045] S3: adding EPDM, erucamide, quaternary ammonium salt, antioxidant and stabilizer into the molten base material, and continuing heating and stirring to obtain a mixture;

[0046] S4: injecting the molten mixture into a bottle cap mold through an injection molding machine, and forming the shape of the bottle cap after cooling;

[0047] S5: Trim and inspect the formed bottle caps.

[0048] Wherein, in the above step S2, the heating temperature is maintained at 175-190°C, in the above step S3, additives are added, and the additives include EPDM, erucamide, quaternary ammonium salt, antioxidant, and stabilizer, wherein EPDM is first added as a plasticizer, and then erucamide, quaternary ammonium salt, antioxidant, and stabilizer are added; in the above step S4, the mold temperature of the injection molding machine is set at 45-75°C, the injection pressure range is 80-140MPa, the holding pressure is approximately 30%-60% of the injection pressure, and the linear speed of the high screw is 0.9m / s.

[0049] A method for separating a polypropylene (PP) plastic bottle cap from a bottle body for recycling and reuse, the recycling and reuse method comprising the following steps:

[0050] S6: Collect waste polypropylene plastic bottle caps and bottles and sort them by color and type;

[0051] S7: repeatedly washing the sorted waste polypropylene plastics to remove dirt and impurities on the surface;

[0052] S8: The cleaned polypropylene plastic is fed into an extruder for melting. During the melting process, the polypropylene plastic is reheated and plasticized;

[0053] S9: Cooling the waste after plasticization, grinding and cutting it after cooling to form polypropylene particles;

[0054] S10: Fill and modify the polypropylene particles according to subsequent applications to improve the performance of the recycled materials;

[0055] S11: Mix the improved waste materials with new materials for application. Mix the waste materials with new materials for use.

[0056] Wherein, in the above step S8, the melting temperature of the extruder is 235°C, the mold temperature is maintained between 50-90°C, the flow channel diameter is 4-7mm, the needle gate length is 1-1.5mm, in the above step S9, the polypropylene waste particles are cut into particles with a diameter of 2-5mm, and in the above step S11, the mixing ratio of waste material to new material does not exceed 1:6.

[0057] Embodiment 1:

[0058] A polypropylene (PP) plastic bottle cap, which is mainly made of polypropylene (PP): the components of the polypropylene (PP) plastic bottle cap mainly include: polypropylene, 50 parts, calcium carbonate, 35 parts, EPDM, 10 parts, erucamide, 0.2 parts, quaternary ammonium salt, 2 parts, antioxidant, 0.5 parts, stabilizer, 2.3 parts, wherein the antioxidant is any one of pomegranate seed extract PSE, grape seed extract GSE, and sea buckthorn seed extract SSE, and the stabilizer is zinc stearate, with the chemical formula of C36H70O4Zn.

[0059] The method for preparing a polypropylene (PP) plastic bottle cap comprises the following steps:

[0060] S1: Raw material preparation: polypropylene and calcium carbonate are crushed and mixed separately to obtain a base material;

[0061] S2: heating, stirring and mixing the base material until the base material is in a molten state;

[0062] S3: adding EPDM, erucamide, quaternary ammonium salt, antioxidant and stabilizer into the molten base material, and continuing heating and stirring to obtain a mixture;

[0063] S4: injecting the molten mixture into a bottle cap mold through an injection molding machine, and forming the shape of the bottle cap after cooling;

[0064] S5: Trim and inspect the formed bottle caps.

[0065] A method for separating a polypropylene (PP) plastic bottle cap from a bottle body for recycling and reuse, the recycling and reuse method comprising the following steps:

[0066] S6: Collect waste polypropylene plastic bottle caps and bottles and sort them by color and type;

[0067] S7: repeatedly washing the sorted waste polypropylene plastics to remove dirt and impurities on the surface;

[0068] S8: The cleaned polypropylene plastic is fed into the extruder for melting. During the melting process,

[0069] Polypropylene plastic is reheated and plasticized;

[0070] S9: Cooling the waste after plasticization, grinding and cutting it after cooling to form polypropylene particles;

[0071] S10: Fill and modify the polypropylene particles according to subsequent applications to improve the performance of the recycled materials;

[0072] S11: Mix the improved waste materials with new materials for application. Mix the waste materials with new materials for use.

[0073] The experimental results show that:

[0074] The polypropylene PP plastic bottle cap prepared in Example 1 is heat-resistant and non-deformable, has high surface strength and good chemical stability. Example 1 maintains high strength and toughness at room temperature. The specific tensile strength is compared with PE plastic and PS plastic. Figure 1 As shown in Figure 1, the wear resistance and low temperature resistance of the polypropylene PP plastic bottle cap prepared in Example 1 are significantly improved, which is nearly 5 times higher than that of the PE matrix. The specific wear resistance is compared with PE plastic and PS plastic. Figure 2 shown.

[0075] The experimental data of Example 1 are compared with those of PE plastic and PS plastic, see Table 1.

[0076] Table 1, PE plastic, PS plastic and related parameter analysis data of Example 1

[0077]

[0078] Embodiment 2:

[0079] A polypropylene (PP) plastic bottle cap, which is mainly made of polypropylene (PP): the components of the polypropylene (PP) plastic bottle cap mainly include: polypropylene, 95 parts, erucamide, 0.2 parts, quaternary ammonium salt, 2 parts, antioxidant, 0.5 parts, stabilizer, 2.3 parts, wherein the antioxidant is any one of pomegranate seed extract PSE, grape seed extract GSE, and sea buckthorn seed extract SSE, and the stabilizer is zinc stearate, with the chemical formula of C36H70O4Zn.

[0080] The method for preparing a polypropylene (PP) plastic bottle cap comprises the following steps:

[0081] S1: Raw material preparation, crushing and mixing polypropylene to obtain a base material;

[0082] S2: heating and stirring the base material until the base material is in a molten state, adding EPDM, erucamide, quaternary ammonium salt, antioxidant, and stabilizer into the molten base material, and continuing to heat and stir to obtain a mixture;

[0083] S3: injecting the molten mixture into a bottle cap mold through an injection molding machine, and forming the shape of the bottle cap after cooling;

[0084] S5: Trim and inspect the formed bottle caps.

[0085] A method for separating a polypropylene (PP) plastic bottle cap from a bottle body for recycling and reuse, the recycling and reuse method comprising the following steps:

[0086] S6: Collect waste polypropylene plastic bottle caps and bottles and sort them by color and type;

[0087] S7: repeatedly washing the sorted waste polypropylene plastics to remove dirt and impurities on the surface;

[0088] S8: The cleaned polypropylene plastic is fed into the extruder for melting. During the melting process,

[0089] Polypropylene plastic is reheated and plasticized;

[0090] S9: The waste material after plasticization is cooled, and then ground and cut to form polypropylene particles.

[0091] The experimental results show that:

[0092] The polypropylene PP plastic bottle cap prepared in Example 2 has high strength and good chemical stability. Example 2 maintains high strength and toughness at room temperature. The specific strength is compared with PE plastic and PS plastic. Figure 3 As shown in the figure, the tensile strength and strength of the polypropylene PP plastic bottle cap prepared in Example 2 are significantly improved, which is nearly 2 times higher than that of the PE matrix. The specific tensile strength is compared with that of PE plastic and PS plastic. Figure 4 shown.

[0093] The experimental data of Example 2 are compared with those of Example 1, PE plastic and PS plastic, see Table 2.

[0094] Table 2, PE plastic, PS plastic, Example 1 and Example 2 related parameter analysis data

[0095]

[0096]

[0097] The present invention discloses a method for separating and recycling a polypropylene (PP) plastic bottle cap from a bottle body, wherein the prepared EPDM composition has high heat resistance and high tensile strength, and magnesium oxide is used as an activator to replace zinc oxide to avoid zinc in the product. The above embodiments are only used to illustrate but not limit the technical embodiments of the present invention, and relevant technicians in the field can make reasonable modifications or equivalent substitutions to the present invention, but any modifications and partial substitutions that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

[0098] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A polypropylene (PP) plastic bottle cap, characterized in that: Polypropylene PP plastic bottle caps are mainly made of polypropylene PP: the ingredients of polypropylene PP plastic bottle caps mainly include: polypropylene, 50-60 parts, calcium carbonate, 30-40 parts, EPDM, 8-15 parts, erucamide, 0.1-0.2 parts, quaternary ammonium salt, 0.5-3 parts, antioxidant, 0.1-0.5 parts, stabilizer, 2-5 parts.

2. A polypropylene PP plastic bottle cap according to claim 1, characterized in that: The antioxidant is any one of pomegranate seed extract PSE, grape seed extract GSE, and seabuckthorn seed extract SSE, and the stabilizer is zinc stearate, with a chemical formula of C36H70O4Zn.

3. A polypropylene PP plastic bottle cap according to claim 1, characterized in that: The preparation method of polypropylene (PP) plastic bottle cap comprises the following steps: S1: raw material preparation, polypropylene and calcium carbonate are crushed and mixed separately to obtain a base material; S2: heating, stirring and mixing the base material until the base material is melted; S3: adding EPDM, erucamide, quaternary ammonium salt, antioxidant and stabilizer into the molten base material, and continuing heating and stirring to obtain a mixture; S4: injecting the molten mixture into a bottle cap mold through an injection molding machine, and forming the shape of the bottle cap after cooling; S5: Trim and inspect the formed bottle caps.

4. The method for preparing a polypropylene PP plastic bottle cap according to claim 3, characterized in that: In the above step S2, the heating temperature is maintained at 175-190°C.

5. The method for preparing a polypropylene PP plastic bottle cap according to claim 3, characterized in that: In the above step S3, auxiliary agents are added, and the auxiliary agents include EPDM, erucamide, quaternary ammonium salt, antioxidant, and stabilizer, wherein EPDM is first added as a plasticizer, and then erucamide, quaternary ammonium salt, antioxidant, and stabilizer are added.

6. The method for preparing a polypropylene PP plastic bottle cap according to claim 3, characterized in that: In the above step S4, the mold temperature of the injection molding machine is set at 45-75°C, the injection pressure range is 80-140MPa, the holding pressure is about 30%-60% of the injection pressure, and the linear speed of the high screw is 0.9m / s.

7. A method for separating and recycling the cap and bottle body of a polypropylene (PP) plastic bottle, characterized in that: The recycling method includes the following steps: S6: Collect waste polypropylene plastic bottle caps and bottles and sort them by color and type; S7: repeatedly washing the sorted waste polypropylene plastics to remove dirt and impurities on the surface; S8: The cleaned polypropylene plastic is fed into an extruder for melting. During the melting process, the polypropylene plastic is reheated and plasticized; S9: Cooling the waste after plasticization, grinding and cutting it after cooling to form polypropylene particles; S10: Fill and modify the polypropylene particles according to subsequent applications to improve the performance of the recycled materials; S11: Mix the improved waste materials with new materials for application. Mix the waste materials with new materials for use.

8. The method for separating and recycling the cap and bottle body of a polypropylene (PP) plastic bottle according to claim 7, characterized in that: In the above step S8, the melt temperature of the extruder is 235°C, the mold temperature is maintained between 50-90°C, the flow channel diameter is 4-7mm, and the needle gate length is 1-1.5mm.

9. The method for separating and recycling the polypropylene PP plastic bottle cap and bottle body according to claim 7, characterized in that: In the above step S9, the polypropylene waste particles are cut into particles with a diameter of 2-5 mm.

10. The method for separating and recycling the cap and bottle body of a polypropylene (PP) plastic bottle according to claim 7, characterized in that: In the above step S11, the mixing ratio of waste material to new material does not exceed 1:6.

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