Methods for recycling plastic waste and products thereof

Abstract

This invention relates to a method for recycling plastic waste and its products. The method involves providing plastic waste and additives; performing a mixing step on the plastic waste and additives to form a composite material; performing a granulation step on the mixed composite material to form a granular composite material; and using a molding step to produce the recycled plastic waste products. This invention's plastic waste recycling method can effectively recycle and reuse plastic waste by mixing plastic waste containing various plastic raw materials with additives, granulating it, and then molding it. The recycled plastic waste products can be molded according to usage requirements and applied to industrial or construction products.

Description

Technical Field

[0001] This invention relates to a method for remanufacturing plastic waste and its products, particularly a method for remanufacturing plastic waste and its products applied to the recycling and reuse of plastic waste. Prior Technology

[0002] Plastic materials have good plasticity, and their rigidity and plasticity can be adjusted by adding appropriate additives according to needs, resulting in a variety of different types of plastic materials. With the rapid development of technology, various plastic materials are used in a variety of products in daily life. However, with the continuous innovation of various products, people are replacing products at an increasingly faster pace, resulting in a large amount of plastic waste and causing many environmental and ecological problems.

[0003] In the recycling of plastic waste, due to the large variety of types of plastic waste and the different material properties of each type, the classification of plastic waste can only be done manually. Moreover, most products are made of multiple different plastic materials during molding, and the cost of disassembling and classifying them individually is high. Therefore, the current efficiency of plastic waste recycling is still not good.

[0004] In order to ensure the sustainable development of the environment and ecology, and in accordance with ESG (Environment, Social, and Governance) indicators, and based on the sustainable operation of industries, how to effectively recycle and reuse plastic waste in industries is one of the important issues in the development of various industries at this stage. Summary of the Invention

[0005] The main purpose of this work is to provide a method for recycling plastic waste and its products, in order to improve the current problem of poor efficiency in recycling plastic waste.

[0006] To achieve the aforementioned objectives, the plastic waste recycling method described in this invention includes: The invention provides plastic waste and additives, wherein the plastic waste can be polypropylene (PP), polyethylene (PE), polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS), polyvinyl chloride (PVC), polyamide (PA), polycarbonate (PC), or a combination thereof, and the additives can be any one of silica sand (silica), calcium phosphate, ceramic powder, tile powder, talc powder, and glass fiber; The plastic waste and the additives are mixed in a mixing process. Under a mixing temperature environment, the plastic waste and the additives are mixed and subjected to cutting, extrusion and stirring to form a composite material after the plastic waste and the additives are uniformly mixed. The mixed composite material is subjected to a granulation step, which pulverizes the composite material to form granular composite material; and The granular composite material is processed into a recycled plastic waste product through a molding step.

[0007] In the plastic waste recycling method described above, the molding step involves hot pressing the recycled plastic waste product using a profile extrusion method at a temperature of 150°C to 220°C.

[0008] The plastic waste recycling method described above includes a pretreatment process, which is performed before the mixing step. The pretreatment process includes: The plastic waste undergoes a pre-mixing step, in which it is subjected to cutting, extrusion, and stirring in a mixing temperature environment to homogenize the plastic waste; and The mixed plastic waste is subjected to a pre-granulation step, which crushes the plastic waste into granular plastic waste.

[0009] In order to achieve the aforementioned purpose, the recycled plastic waste products provided in this invention are made by the plastic waste recycling method described above. The recycled plastic waste products contain 21% to 59% plastic materials and 40% to 78% additive materials by weight, with the remainder being impurities.

[0010] This invention relates to a method for recycling plastic waste. The method involves mixing plastic waste with additives, granulating the mixture, and then molding it to form recycled plastic waste products. These recycled plastic waste products and their derivatives offer the following advantages: 1. Accepts mixed plastic waste as raw material: The plastic waste recycling method of this invention can use the mixing equipment to mix the plastic waste and additives, so that the material composition can ensure that different types of plastics are evenly distributed under repeated crushing and homogenization treatment, making the structure of the recycled plastic waste products more stable. 2. Significantly reduces the need for tedious sorting and cleaning: This innovative plastic waste recycling method can crush and homogenize plastic waste and additives through mixing, while precise temperature and pressure control removes biological contaminants from food, oils and organic residues from plastic waste, thereby making the material composition more uniform without the need for tedious pre-cleaning and pre-sorting operations. 3. Manufacturing high-strength composite material products: This invention's plastic waste recycling method can form granular composite materials in the granulation step, and then form high-density molecularly bonded recycled plastic waste products through a high-pressure extrusion molding step. This improves the overall material compactness of the recycled plastic waste products and gives them characteristics such as high compressive strength, high load-bearing capacity, low water absorption, and high freeze-thaw cycle resistance, meeting international standards. This allows the recycled plastic waste products to be used not only in building materials such as paving bricks and floor tiles, but also in extreme environmental conditions. 4. In line with the principles of circular economy: The plastic waste recycling method of this invention mainly involves mixing and adding various plastic waste materials, followed by granulation and molding steps to produce recycled plastic waste products. This not only effectively recycles and reuses various difficult-to-classify plastic wastes to solve environmental problems, but also provides high-strength recycled plastic waste products for use as paving bricks, floor tiles and other building materials, thereby providing the construction industry with cost-effective alternative materials, thus conforming to the principles of circular economy. Simple Explanation of the Diagram

[0011] Figure 1: A block diagram of a preferred embodiment of the plastic waste recycling method of this invention. Figure 2: Block diagram of another preferred embodiment of the plastic waste recycling method of this invention. Implementation

[0012] Please refer to Figure 1, which shows a preferred embodiment of the plastic waste recycling method of this invention, wherein the plastic waste recycling method includes the following steps when executed.

[0013] The invention provides plastic waste and additives; wherein the plastic waste can be plastic waste from daily life, and the plastic waste can be any one or a combination of polypropylene (PP), polyethylene (PE), polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS), polyvinyl chloride (PVC), polyamide (PA), and polycarbonate (PC); and the additives can be non-metallic construction waste, such as silica sand (silica), calcium phosphate, ceramic powder, tile powder, talc powder, and glass fiber.

[0014] Next, the operator can put the plastic waste and the additives into the mixing equipment to perform the mixing step, and in the mixing temperature environment, the plastic waste and the additives are mixed and subjected to cutting, extrusion and stirring to form a composite material after the plastic waste and the additives are uniformly mixed.

[0015] The mixed composite material is then fed into a granulation device to perform a granulation step, which crushes the composite material into granular composite material.

[0016] Finally, the granular composite material is fed into a molding equipment for molding, and a recycled plastic waste product is produced.

[0017] The recycled plastic waste products of this invention are made using the aforementioned recycled plastic waste manufacturing method. The recycled plastic waste products contain 21% to 59% plastic materials and 40% to 78% additive materials by weight, with the remainder being impurities.

[0018] As shown in Figure 1, the present invention’s plastic waste recycling method can uniformly mix different plastic raw materials and additives in the plastic waste through a mixing step to form a composite material, and make the connection between the different plastic raw materials and additives in the plastic waste tighter. Then, the granulation step is used to crush the plastic waste into granular composite material to facilitate the subsequent molding step.

[0019] This invention’s plastic waste recycling method can be applied to the treatment of various unclassified thermoplastic wastes, including plastic wastes that are traditionally considered difficult to recycle, such as: mixed plastics and contaminated plastic products containing any one of the following polymers or combinations thereof: polypropylene (PP), polyethylene (PE), polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS), polyvinyl chloride (PVC), polyamide (PA), polycarbonate (PC).

[0020] The aforementioned plastic waste recycling method utilizes a multi-screw structure in the mixing process of the mixing equipment to shear, extrude, and agitate the plastic waste and additives. This repeated crushing and homogenization, coupled with precise temperature and pressure control, ensures a uniform mixture of different types of plastics and removes biological contaminants from food, oils, and organic residues from the plastic waste. This reduces the need for pre-cleaning and pre-sorting of plastic waste. Furthermore, oxidative degradation and vacuum degassing technologies remove volatile organic compounds (VOCs) and microbial byproducts, resulting in a more biocompatible composite material after mixing of plastic waste and additives.

[0021] Furthermore, by precisely controlling the parameters related to shear force, temperature change range, and pressure regulation during the mixing process, the material can be continuously flowed, thereby improving the wetting and interfacial bonding between plastic waste and additives, resulting in a composite material with a dense structure, high compressive strength, uniform load distribution, and impact resistance.

[0022] Furthermore, during the mixing process, the mixing equipment can perform precise temperature control and short-term heat transfer reaction treatment, thereby reducing the degradation of plastic waste, promoting the mutual diffusion and chain entanglement between molecules, and enabling the polymers and additives in the plastic waste to form chemical chains at the microscopic level. In this controlled reaction environment, the additives can be directly functionalized during the extrusion process, thereby improving compatibility, eliminating weak interface regions, reducing unnecessary thermal degradation, and effectively suppressing the release of harmful gases.

[0023] Precise pressure control ensures that the polymer uniformly coats the additives, preventing the release of microplastics and forming a chemically stable composite material. This not only maintains long-term durability but also significantly reduces carbon dioxide emissions by reducing the use of cement-based materials. Since this innovative plastic waste recycling method does not rely on cement as a binder, the recycled plastic waste products can reduce carbon dioxide emissions by up to 90% compared to traditional concrete building materials under the same compressive strength.

[0024] In a preferred embodiment of the manufacturing method for the plastic waste of this invention, during the molding step, the molding equipment employs existing shaped extrusion methods and is equipped with multiple dies. These dies, combined with the shaped extrusion method, are used to hot-press the recycled plastic waste product at a temperature of 150°C to 220°C. The shape of the recycled plastic waste product can be adjusted according to usage requirements. High-pressure shaped extrusion ensures high-density molecular bonding of the material, reducing voids and increasing the overall material compactness. This results in the production of recycled plastic waste products with high compressive strength, load-bearing capacity, and low water absorption. The compressive strength of the recycled plastic waste product is 3 to 4 times that of standard concrete bricks, and its load-bearing capacity is more than 10 times higher. Furthermore, the recycled plastic waste product exhibits extremely high resistance to freeze-thaw cycles, meets international standards, and is suitable for applications under extreme environmental conditions.

[0025] Furthermore, the molding equipment utilizes precise pressure control combined with die extrusion technology, along with laser or waterjet cutting, to produce recycled plastic waste products. This effectively encapsulates plastic waste and additives, mechanically locking plastic particles within a dense structural matrix, thereby significantly reducing microplastic release. Moreover, the high-pressure extrusion and optimized cooling stages further strengthen the bond between plastic waste and additives, ensuring the recycled plastic waste products maintain chemical inertness and physical stability when exposed to the environment.

[0026] Furthermore, this invention's method for remanufacturing plastic waste can directly mix non-metallic construction waste as an additive with plastic waste to form a composite material. The mixing process requires no water or additional chemical binders, thus reducing reliance on virgin materials and optimizing the thermal properties of the recycled plastic waste. Moreover, the manufacturing process requires almost no water-based treatment, which helps reduce environmental impact and improve production efficiency.

[0027] As shown in Figure 2, in another preferred embodiment of the plastic waste recycling method of this invention, the plastic waste recycling method can perform a pre-treatment process before performing the mixing step. During the pre-treatment process, the operator can first place the plastic waste into a mixing equipment to perform a pre-mixing step, and apply cutting, extrusion, and stirring to the plastic waste in a mixing temperature environment to homogenize it. Then, the mixed plastic waste is placed into a granulation equipment to perform a pre-granulation step, causing the plastic waste to be crushed into granular plastic waste. The granular plastic waste and the additives can then be input into the mixing equipment to perform the mixing step.

[0028] As shown in Figure 2, the pre-treatment process allows for the initial mixing of plastic waste through a pre-mixing step. By performing actions such as cutting, extrusion, and stirring at the mixing temperature, different plastic raw materials in the plastic waste can be mixed together, thereby making the overall plastic waste more homogeneous. Then, the mixed plastic waste is placed into a granulation device to perform a pre-granulation step, thereby reducing the volume of the plastic waste to facilitate subsequent mixing steps with added materials and further improving the mixing effect.

[0029] In summary, the plastic waste recycling method of this invention can form recycled plastic waste products by mixing plastic waste containing various plastic raw materials with additives, granulating the mixture, and then molding it. These recycled plastic waste products can be molded according to usage requirements and applied to industrial or building products, thus enabling the effective recycling and reuse of plastic waste.

[0030] none

Claims

1. A method for remanufacturing plastic waste, comprising: providing plastic waste and additives, wherein the plastic waste can be polypropylene (PP), polyethylene (PE), polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS), polyvinyl chloride (PVC), polyamide (PA), polycarbonate (PC), or a combination thereof, and the additives can be any one of silica sand (silica), calcium phosphate, ceramic powder, tile powder, talc powder, and glass fiber; and performing a pretreatment process, wherein the pretreatment process comprises: performing a pre-mixing step on the plastic waste, wherein the plastic waste is subjected to cutting, extrusion, and stirring in a mixing temperature environment to homogenize the plastic waste; And perform a pre-granulation step on the mixed plastic waste to crush the plastic waste into granular plastic waste; The granular plastic waste and the additives are mixed in a mixing process. In a mixing temperature environment, the granular plastic waste and the additives are mixed and subjected to cutting, extrusion and stirring to form a composite material after the granular plastic waste and the additives are uniformly mixed. The mixed composite material is subjected to a granulation step to crush the composite material into granular composite material; And to produce a recycled plastic waste product by molding the granular composite material.

2. The plastic waste recycling method as described in claim 1, wherein the molding step is performed by extrusion molding and hot pressing of the recycled plastic waste product at a temperature of 150°C to 220°C.

3. A recycled plastic waste product, which is made by the plastic waste recycling method as described in claim 1 or 2, wherein the recycled plastic waste product comprises 21% to 59% plastic material and 40% to 78% additive material by weight, with the remainder being impurities.

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