Plastic product prepared from waste mulching film and preparation method of plastic product

Abstract

The invention discloses a plastic product prepared from waste mulching films and a preparation method of the plastic product, relates to the field of recycling of mulching films, and solves the problems that in the prior art, when the waste mulching films are recycled, after the mulching films are crushed, mulching film particles need to be cleaned with water, so that a large amount of water resources are consumed in the production process, and the production cost is reduced. And a certain amount of sewage can be generated. According to the invention, the recycled waste plastic is crushed without cleaning, the linear (longitudinal) mulching film raw material low density polyethylene (LDPE) is used as a cross-linking agent, and a reinforcing material is added to improve the environmental adaptability such as compression resistance, freezing resistance, fracture resistance and aging resistance of the mulching film; the mulching film impurity removal device can be processed into energy-saving and environment-friendly novel building materials such as plastic footpath bricks, road barriers, agricultural canal profiles and trays for transportation and cargo carrying of the building materials, the requirement for impurities entrained by an agricultural film is not strict, and in the mulching film impurity removal process, water cleaning and manual impurity removal procedures are not needed, so that water resources are saved.

Description

Technical Field

[0001] The invention relates to the field of recycling and reuse of ground films, and in particular to a plastic product made from waste ground films and a preparation method thereof. Background Art

[0002] In order to ensure the effective supply of agricultural products in my country, mulch films and pesticides are increasingly used in agricultural production. Since the 1980s, my country has introduced agricultural film technology and promoted its application in the arid northwest region and high-altitude cold regions. Up to now, my country's agricultural film production has jumped to the first place in the world, and the annual usage accounts for about 62% of the world's usage. Although agricultural mulch films play a huge role in water retention, promoting soil nutrient conversion and absorption, and inhibiting weed growth, their main component, polyethylene, is difficult to degrade under natural conditions, and film fragments can stay in the soil for more than 200 years.

[0003] In order to prevent the impact of plastic products such as ground film on the ecology and protect public health, various parts of the country have established unified recycling and centralized disposal models to control agricultural plastic pollution. However, the recycling and reuse of waste plastics such as pesticide packaging and ground film is still a technical or economic problem. If the recycled waste plastics are treated by conventional methods, such as washing and removing impurities to produce recycled plastic particles for sale, a large amount of low-concentration pesticide wastewater is generated during the cleaning of pesticide packaging, and a large amount of dust and crop straw branches and leaves are mixed in when the ground film is recycled. A large amount of water resources are consumed during cleaning, and the cost of manual impurity removal (crop straw) and subsequent sewage purification treatment is high. In addition, environmental problems such as sewage, dust and volatile organic compounds (VOCs) generated during the production process have led to slow progress in the recycling and utilization of agricultural waste plastics.

[0004] For example, in the patent application with publication number CN114752159A, a pallet synthesized from waste mulch and modified red mud is disclosed, which includes the following raw materials in parts by weight: 70-80 parts of waste mulch, 0.2-0.7 parts of initiator, 1.3-2.8 parts of toughening agent, 0.5-1.6 parts of antioxidant, 0.4-1.7 parts of lubricant and 1.5-3.5 parts of coupling agent; this invention uses waste mulch as the main raw material and modified red mud as the toughening agent, thus realizing the recycling of resources and avoiding the waste of resources, and at the same time can also enhance the impact resistance of the pallet. Since glass fiber is the reinforcing fiber, its high strength can improve the physical and mechanical properties of the pallet on the basis of ensuring that the raw materials have good processing properties, and can also improve the dimensional stability and heat resistance of the pallet.

[0005] The above patent uses waste mulch and modified red mud to make pallets. However, in the production process, the waste mulch needs to be crushed to a particle size of 8-10 cm, then placed in clean water for ultrasonic washing for 30-40 minutes, and then placed in a detergent solution for repeated ultrasonic washing 2-3 times. Therefore, the production process not only consumes a large amount of water resources, but also produces a certain amount of sewage, which is not conducive to use in water-scarce areas such as Xinjiang. Summary of the invention

[0006] The purpose of the present invention is to provide a plastic product made of waste mulch film and a preparation method thereof, so as to solve the problem that in the prior art of recycling and reusing waste mulch film, after the mulch film is crushed, water needs to be used to clean the mulch film particles, so that a large amount of water resources is consumed in the production process, and a certain amount of sewage is generated.

[0007] The technical solution adopted by the present invention is as follows: a plastic product made of waste mulch film, characterized in that it includes the following raw materials in parts by weight: 75-130 parts of waste mulch film, 7.5-13 parts of lubricant, 15-26 parts of calcium carbonate, 4.6-8 parts of antioxidant and 22-39 parts of toughening agent.

[0008] Furthermore, the antioxidant is one or both of 2,6-di-tert-butyl-p-cresol and dilauryl thiodipropionate.

[0009] Furthermore, the ratio of the 2,6-di-tert-butyl-p-cresol to the dilauryl thiodipropionate is 1:0.5-1:1.5.

[0010] Furthermore, the lubricant is talcum powder.

[0011] Furthermore, the toughening agent is glass fiber.

[0012] A method for recycling and reusing waste mulch film comprises the following steps:

[0013] S1: Use a sieve to preliminarily screen the waste ground film to remove dust and other impurities in the ground film

[0014] S2: Use a crusher to crush the waste mulch film, and the particle size of the crushed mulch film is 1 cm;

[0015] S3: Use the specific gravity method to screen the soil from the mulch particles. When using the specific gravity method to screen, the mulch particles containing soil are placed in a container on a vibrating table. During the vibration of the vibrating table, the mulch particles are lighter and will move upward, while the soil is heavier and sinks, thereby completing the separation of the two.

[0016] S4: placing the mulch particles processed in S3 in a drum dry rubbing machine, the inner wall of which has a rough surface, and the material is continuously rolled and rubbed between the drum and the inner wall to remove the soil attached to the mulch particles.

[0017] S6: using wind selection equipment to screen the ground film particles processed in S4 again to separate the ground film particles from the soil;

[0018] S6: The mulch film particles that have been screened for multiple times are heated to a molten state. The high temperature during the heating process can decompose the residual pesticides, greatly reducing the secondary pollution of the pesticides to the environment. At the same time, talcum powder, calcium carbonate, 2,6-di-tert-butyl-p-cresol, dilauryl thiodipropionate and glass fiber are added and mixed;

[0019] S7: placing the molten mixture obtained in S3 into a mold and press-molding it into a desired product.

[0020] Furthermore, in S4, the molten mixture is cooled, crushed into particles, put into a mold and press-formed to prepare the desired product.

[0021] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0022] The present invention crushes the recycled waste plastics without washing, utilizes the linear (longitudinal) low-density polyethylene (LDPE) as a raw material of ground film as a cross-linking agent, and adds reinforcing materials to improve its environmental adaptability such as compression resistance, frost resistance, bending resistance and aging resistance, and then processes it into energy-saving and environment-friendly new building materials such as plastic walkway bricks, road barriers, agricultural water channel profiles, and pallets for transporting cargo. The requirements for impurities entrained in agricultural films are not strict, and in the process of removing impurities from the ground film, water washing and manual impurity removal procedures are not required, thereby saving water resources. In addition, the equipment and facilities are simple, the production cost is low, there is no secondary pollution in the production process, the mechanical properties of the finished plastic products are excellent, the products are widely used and have high added value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] A plastic product made of waste mulch film comprises the following raw materials in parts by weight: 75 parts of waste mulch film, 7.5 parts of talcum powder, 15 parts of calcium carbonate, 2.3 parts of 2,6-di-tert-butyl-p-cresol, 2.3 parts of dilauryl thiodipropionate and 22 parts of glass fiber.

[0028] The main component of recycled waste mulch is low-density polyethylene (LDPE), and its mechanical properties cannot meet the requirements of industrial use if it is directly recycled. Therefore, modified additives are added to enhance its compression resistance, anti-aging, resistance to drastic temperature differences, and resistance to acid rain corrosion.

[0029] A method for recycling and reusing waste mulch film comprises the following steps:

[0030] S1: Use a sieve to preliminarily screen the waste ground film to remove dust and other impurities in the ground film

[0031] S2: Use a crusher to crush the waste mulch film, and the particle size of the crushed mulch film is 0.3 cm;

[0032] S3: Use the specific gravity method to screen the soil from the mulch particles. When using the specific gravity method to screen, the mulch particles containing soil are placed in a container on a vibrating table. During the vibration of the vibrating table, the mulch particles are lighter and will move upward, while the soil is heavier and sinks, thereby completing the separation of the two.

[0033] S4: placing the mulch particles processed in S3 in a drum dry rubbing machine, the inner wall of which has a rough surface, and the material is continuously rolled and rubbed between the drum and the inner wall to remove the soil attached to the mulch particles.

[0034] S6: using wind selection equipment to screen the ground film particles processed in S4 again to separate the ground film particles from the soil;

[0035] S6: The mulch film particles that have been screened for multiple times are heated to a molten state. The high temperature during the heating process can decompose the residual pesticides, greatly reducing the secondary pollution of the pesticides to the environment. At the same time, talcum powder, calcium carbonate, 2,6-di-tert-butyl-p-cresol, dilauryl thiodipropionate and glass fiber are added and mixed;

[0036] S7: placing the molten mixture obtained in S3 into a mold and press-molding it into a desired product.

[0037] Example 2

[0038] A plastic product made of waste mulch film comprises the following raw materials in parts by weight: 85 parts of waste mulch film, 8.5 parts of talcum powder, 17 parts of calcium carbonate, 2.5 parts of 2,6-di-tert-butyl-p-cresol, 2.5 parts of dilauryl thiodipropionate and 26 parts of glass fiber.

[0039] A method for recycling and reusing waste mulch film comprises the following steps:

[0040] S1: Use a sieve to preliminarily screen the waste ground film to remove dust and other impurities in the ground film

[0041] S2: Use a crusher to crush the waste mulch film, and the particle size of the crushed mulch film is 0.6 cm;

[0042] S3: Use the specific gravity method to screen the soil from the mulch particles. When using the specific gravity method to screen, the mulch particles containing soil are placed in a container on a vibrating table. During the vibration of the vibrating table, the mulch particles are lighter and will move upward, while the soil is heavier and sinks, thereby completing the separation of the two.

[0043] S4: placing the mulch particles processed in S3 in a drum dry rubbing machine, the inner wall of which has a rough surface, and the material is continuously rolled and rubbed between the drum and the inner wall to remove the soil attached to the mulch particles.

[0044] S6: using wind selection equipment to screen the ground film particles processed in S4 again to separate the ground film particles from the soil;

[0045] S6: The mulch film particles that have been screened for multiple times are heated to a molten state. The high temperature during the heating process can decompose the residual pesticides, greatly reducing the secondary pollution of the pesticides to the environment. At the same time, talcum powder, calcium carbonate, 2,6-di-tert-butyl-p-cresol, dilauryl thiodipropionate and glass fiber are added and mixed;

[0046] S7: placing the molten mixture obtained in S3 into a mold and press-molding it into a desired product.

[0047] Example 3

[0048] A plastic product made of waste mulch film comprises the following raw materials in parts by weight: 100 parts of waste mulch film, 10 parts of talcum powder, 20 parts of calcium carbonate, 3 parts of 2,6-di-tert-butyl-p-cresol, 3 parts of dilauryl thiodipropionate and 30 parts of glass fiber.

[0049] A method for recycling and reusing waste mulch film comprises the following steps:

[0050] S1: Use a sieve to preliminarily screen the waste ground film to remove dust and other impurities in the ground film

[0051] S2: Use a crusher to crush the waste mulch film, and the particle size of the crushed mulch film is 1.0 cm;

[0052] S3: Use the specific gravity method to screen the soil from the mulch particles. When using the specific gravity method to screen, the mulch particles containing soil are placed in a container on a vibrating table. During the vibration of the vibrating table, the mulch particles are lighter and will move upward, while the soil is heavier and sinks, thereby completing the separation of the two.

[0053] S4: placing the mulch particles processed in S3 in a drum dry rubbing machine, the inner wall of which has a rough surface, and the material is continuously rolled and rubbed between the drum and the inner wall to remove the soil attached to the mulch particles.

[0054] S6: using wind selection equipment to screen the ground film particles processed in S4 again to separate the ground film particles from the soil;

[0055] S6: The mulch film particles that have been screened for multiple times are heated to a molten state. The high temperature during the heating process can decompose the residual pesticides, greatly reducing the secondary pollution of the pesticides to the environment. At the same time, talcum powder, calcium carbonate, 2,6-di-tert-butyl-p-cresol, dilauryl thiodipropionate and glass fiber are added and mixed;

[0056] S7: placing the molten mixture obtained in S3 into a mold and press-molding it into a desired product.

[0057] Example 4

[0058] A plastic product made of waste mulch film comprises the following raw materials in parts by weight: 115 parts of waste mulch film, 11 parts of talcum powder, 23 parts of calcium carbonate, 3.5 parts of 2,6-di-tert-butyl-p-cresol, 3.5 parts of dilauryl thiodipropionate and 35 parts of glass fiber.

[0059] A method for recycling and reusing waste mulch film comprises the following steps:

[0060] S1: Use a sieve to preliminarily screen the waste ground film to remove dust and other impurities in the ground film

[0061] S2: Use a crusher to crush the waste mulch film, and the particle size of the crushed mulch film is 1.2 cm;

[0062] S3: Use the specific gravity method to screen the soil from the mulch particles. When using the specific gravity method to screen, the mulch particles containing soil are placed in a container on a vibrating table. During the vibration of the vibrating table, the mulch particles are lighter and will move upward, while the soil is heavier and sinks, thereby completing the separation of the two.

[0063] S4: placing the mulch particles processed in S3 in a drum dry rubbing machine, the inner wall of which has a rough surface, and the material is continuously rolled and rubbed between the drum and the inner wall to remove the soil attached to the mulch particles.

[0064] S6: using wind selection equipment to screen the ground film particles processed in S4 again to separate the ground film particles from the soil;

[0065] S6: The mulch film particles that have been screened for multiple times are heated to a molten state. The high temperature during the heating process can decompose the residual pesticides, greatly reducing the secondary pollution of the pesticides to the environment. At the same time, talcum powder, calcium carbonate, 2,6-di-tert-butyl-p-cresol, dilauryl thiodipropionate and glass fiber are added and mixed;

[0066] S7: placing the molten mixture obtained in S3 into a mold and press-molding it into a desired product.

[0067] Example 5

[0068] A plastic product made of waste mulch film comprises the following raw materials in parts by weight: 130 parts of waste mulch film, 13 parts of talcum powder, 26 parts of calcium carbonate, 4 parts of 2,6-di-tert-butyl-p-cresol, 4 parts of dilauryl thiodipropionate and 39 parts of glass fiber.

[0069] A method for recycling and reusing waste mulch film comprises the following steps:

[0070] S1: Use a sieve to preliminarily screen the waste ground film to remove dust and other impurities in the ground film

[0071] S2: Use a crusher to crush the waste mulch film, and the particle size of the crushed mulch film is 1.5 cm;

[0072] S3: Use the specific gravity method to screen the soil from the mulch particles. When using the specific gravity method to screen, the mulch particles containing soil are placed in a container on a vibrating table. During the vibration of the vibrating table, the mulch particles are lighter and will move upward, while the soil is heavier and sinks, thereby completing the separation of the two.

[0073] S4: placing the mulch particles processed in S3 in a drum dry rubbing machine, the inner wall of which has a rough surface, and the material is continuously rolled and rubbed between the drum and the inner wall to remove the soil attached to the mulch particles.

[0074] S6: using wind selection equipment to screen the ground film particles processed in S4 again to separate the ground film particles from the soil;

[0075] S6: The mulch film particles that have been screened for multiple times are heated to a molten state. The high temperature during the heating process can decompose the residual pesticides, greatly reducing the secondary pollution of the pesticides to the environment. At the same time, talcum powder, calcium carbonate, 2,6-di-tert-butyl-p-cresol, dilauryl thiodipropionate and glass fiber are added and mixed;

[0076] S7: placing the molten mixture obtained in S3 into a mold and press-molding it into a desired product.

[0077] Example 6

[0078] The difference between this embodiment and embodiment 1 is that in S4, the molten mixture is cooled, crushed into particles, put into a mold and press-formed to prepare the desired product.

[0079] The waste mulch film is melted and put into a mold for pressure forming to prepare bricks. The prepared bricks are then tested for mechanical properties, mainly including compressive strength and flexural (bending) strength, to analyze the feasibility of producing building materials.

[0080] Table 1 Plastic brick density data

[0081]

[0082] The experimental results show that the average density of plastic bricks is 1085.2kg / m3. The density of solid concrete bricks commonly used in the construction industry is about 1681-2099kg / m3. It can be seen that the density of plastic bricks is lower than that of solid concrete bricks, and they have a lightweight and heat-insulating effect.

[0083] Plastic bricks will inevitably be soaked by rainwater during use, and the water absorption rate directly affects their durability, so it is necessary to conduct research on their durability. The water absorption rate of plastic bricks is shown in Table 2.

[0084] Table 2 Water absorption data of plastic bricks

[0085]

[0086]

[0087] The average water absorption rate of the plastic bricks was calculated to be 0.054%, which is in line with the 14% specified in the GB / T21144-2007 Concrete Solid Brick Standard (Table 3). This shows that the plastic bricks have low water absorption and excellent durability.

[0088] The compressive strength of plastic bricks will affect their engineering properties. In the preliminary experiment, an electronic universal testing machine was used to test their mechanical properties. The compressive properties of plastic bricks placed horizontally and vertically are shown in Table 3.

[0089] Table 3 Compressive performance data of plastic bricks

[0090]

[0091] The compressive strength meets the MU15 strength grade of GB5101-2017 National Standard for Sintered Ordinary Bricks. Comprehensive analysis shows that the use of agricultural waste mulch to prepare plastic bricks can greatly improve the mechanical properties of plastic bricks and is feasible for use in the building materials industry.

Claims

1. A plastic product made from waste mulch film, characterized in that: The method comprises the following raw materials in parts by weight: 75-130 parts of waste ground film, 7.5-13 parts of lubricant, 15-26 parts of calcium carbonate, 4.6-8 parts of antioxidant and 22-39 parts of toughening agent.

2. The plastic product made from waste mulch film according to claim 1, characterized in that: The antioxidant is one or two of 2,6-di-tert-butyl-p-cresol and dilauryl thiodipropionate.

3. The plastic product made from waste mulch film according to claim 1, characterized in that: The lubricant is talcum powder.

4. The plastic product made from waste mulch film according to claim 1, characterized in that: The toughening agent is glass fiber.

5. The plastic product made from waste mulch film according to claim 2, characterized in that: The ratio of the 2,6-di-tert-butyl-p-cresol to the dilauryl thiodipropionate is 1:0.5-1:1.

5.

6. The method for preparing a plastic product made from waste mulch film according to claims 1-5, characterized in that: The steps include: S1: Use a sieve to preliminarily screen the waste ground film to remove dust and other impurities in the ground film S2: Use a crusher to crush the waste mulch film, and the particle size of the crushed mulch film is 0.3cm to 1.5cm; S3: Screening the soil from the mulch film particles using the specific gravity method; S4: placing the mulch particles processed in S3 in a drum dryer to remove the soil attached to the mulch particles. S6: using wind selection equipment to screen the ground film particles processed in S4 again to separate the ground film particles from the soil; S6: The mulch film particles that have been screened for multiple times are heated to a molten state. The high temperature during the heating process can decompose the residual pesticides, greatly reducing the secondary pollution of the pesticides to the environment. At the same time, talcum powder, calcium carbonate, 2,6-di-tert-butyl-p-cresol, dilauryl thiodipropionate and glass fiber are added and mixed; S7: placing the molten mixture obtained in S3 into a mold and press-molding it into a desired product.

7. The method for preparing a plastic product made from waste mulch film according to claim 6, characterized in that: In S3, when using the specific gravity method for screening, the mulch particles containing soil are placed in a container on a vibrating table. During the vibration of the vibrating table, the mulch particles are lighter and will move upward, while the soil is heavier and will sink, thus completing the separation of the two.

8. The method for preparing a plastic product made from waste mulch film according to claim 6, characterized in that: In S4, the inner wall of the drum dry rubbing machine is provided with a rough surface. When the motor drives the drum to rotate, the material continuously rolls and rubs between the drum and the inner wall to remove the soil attached to the mulch particles.

9. The method for preparing a plastic product made from waste mulch film according to claim 6, characterized in that: In S6, the molten mixture is cooled, crushed into particles, put into a mold and pressed to prepare a desired product.

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