CN110564105A

CN110564105A - Regenerated plastic particles and preparation process thereof

Info

Publication number: CN110564105A
Application number: CN201910835182.7A
Authority: CN
Inventors: 边舒怡; 边寿鹏
Original assignee: Tianjin Yatai Futong Metal Products Co Ltd
Current assignee: Tianjin Yatai Futong Metal Products Co Ltd
Priority date: 2019-09-05
Filing date: 2019-09-05
Publication date: 2019-12-13

Abstract

The invention discloses a regenerated plastic particle and a preparation process thereof, belonging to the technical field of plastic recycling. The technical scheme is characterized in that the regenerated plastic particles comprise the following components in parts by weight: 500-700 parts of thermosetting plastic, 300-450 parts of thermoplastic plastic, 3-8 parts of lubricant, 5-10 parts of antioxidant, 2-6 parts of plasticizer and 2-6 parts of coupling agent; the particle size of the thermosetting plastic after mechanical and physical activation treatment is 0.003-0.2 mm. The regenerated plastic particles have excellent performances of heat insulation, wear resistance, insulation and the like, and the efficiency of recycling the thermosetting plastic is improved. The invention also discloses a preparation process of the regenerated plastic particles, which is simple and suitable for industrial application.

Description

Regenerated plastic particles and preparation process thereof

Technical Field

the invention relates to the technical field of plastic recycling, in particular to a regenerated plastic particle and a preparation process thereof.

Background

with the development of polymer material industry, plastics have been widely applied to various fields, and become an important part in people's life. However, as a chemical recycled plastic particle, the plastic brings convenience to daily life of people, and simultaneously brings great influence to the global environment due to the defect of deadly and difficult degradation.

According to the processing property of plastics, it can be divided into two categories of thermoplastic plastics and thermosetting plastics. Thermoplastics are linear molecular chain structures, elastic and plastic, soluble in solvents, meltable, and can be repeatedly processed and molded, such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, and the like. Thermosetting plastics are of a three-dimensional network cross-linked molecular chain structure, and after solidification and shaping, the thermosetting plastics cannot be melted again, cannot be dissolved in a solvent, and can only swell, such as phenolic plastics, polyurethane plastics, epoxy resins, unsaturated polyesters and the like. There have been many studies on the recycling of thermoplastics, and various recycling techniques have been developed.

But the recycling of thermosetting plastics faces a serious challenge, which causes serious resource waste and environmental pollution. The thermosetting plastic has excellent performances of heat insulation, wear resistance, insulation, high voltage resistance and the like, and is widely applied. Therefore, the development of the regenerated thermosetting plastic has important significance for saving resources, protecting the environment and realizing sustainable development.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide the following steps: provides a recycled plastic particle which has excellent performances of heat insulation, wear resistance, insulation and the like and improves the efficiency of recycling the thermosetting plastic.

The first purpose of the invention is realized by the following technical scheme: the recycled plastic particles comprise the following components in parts by weight: 500-700 parts of thermosetting plastic, 300-450 parts of thermoplastic plastic, 3-8 parts of lubricant, 5-10 parts of antioxidant, 2-6 parts of plasticizer and 2-6 parts of coupling agent; the particle size of the thermosetting plastic after mechanical and physical activation treatment is 0.003-0.2 mm.

Under the action of mechanical and physical properties, the chemical structure and chemical properties of the thermosetting plastic are changed, the reticular cross-linked molecular chains are broken to generate active groups, the cross-linking density is reduced, and the thermosetting plastic has reactivity and remolding capability after being activated.

the lubricant is one or more of stearic acid, polyethylene wax or paraffin. The lubricant can improve the processability, improve the stability and uniformity of each component of the mixture and ensure that the final plastic products have the same property and quality.

The antioxidant is one or more selected from antioxidant 1010, antioxidant 2246 and antioxidant 264. The antioxidant can capture active free radicals to generate inactive free radicals, or can decompose polymer hydroperoxide generated in the oxidation process to stop chain reaction, delay the oxidation process of plastics and prolong the service life.

The plasticizer is one or more of acetyl triethyl citrate, phosphate or glyceryl monostearate. The plasticizer can reduce the melting temperature, viscosity and hardness of the plastic, and increase the fluidity of the plastic and the flexibility of products, thereby improving the processability and the service performance of the plastic.

the coupling agent is one or more of silane, titanate and organic acid chromium complex. The coupling agent is also called a surface modifier. It can reduce the viscosity of synthetic resin melt in the course of plastic processing, and can improve the dispersity of filling agent to raise processing property, so that it can make the product obtain good surface quality and mechanical, thermal and electric properties.

by adopting the scheme, the activated thermosetting plastic serving as the main material and the thermoplastic plastic serving as the auxiliary material are mixed under the mechanical and physical effects, and then the auxiliary materials such as the lubricant, the antioxidant, the plasticizer, the coupling agent and the like are used in a matching manner, so that the regenerated plastic particles have excellent performances such as heat insulation, wear resistance, insulation and the like, and the recycling efficiency of the thermosetting plastic is improved.

the invention is further configured to: the thermosetting plastic comprises one or more of phenolic plastic, polyurethane plastic or epoxy resin.

The phenolic resin is a polycondensation product of phenol and formaldehyde under the action of a catalyst, and the phenolic plastic is a general name of plastics taking the phenolic resin as a matrix. The phenolic resin has the excellent characteristics of low cost, high mechanical strength, toughness, wear resistance, high temperature resistance, corrosion resistance, good electrical insulation performance and the like.

polyurethanes, collectively known as polyurethanes, are a general name for high molecular compounds containing recurring urethane groups (NHCOO) in the main chain, which are prepared by polyaddition of various isocyanates with polyhydroxyl compounds in the presence of catalysts. At present, a large amount of polyurethane waste materials come from various polyurethane plastic products, such as heat insulating materials used in buildings, refrigerators and cold storages.

Epoxy resins generally refer to organic macromolecular compounds containing two or more epoxy groups in the molecule. The epoxy resin has excellent bonding, corrosion resistance, forming capability and thermal stability.

By adopting the scheme, the type of the thermosetting plastic is optimized, and common thermosetting plastics such as phenolic plastics, polyurethane plastics or epoxy resin which are widely applied are selected, so that the recycling efficiency of the waste thermosetting plastic can be greatly improved.

The invention is further configured to: the thermoplastic comprises one or more of polyethylene, polypropylene or polyvinyl chloride.

Polyethylene is a thermoplastic resin obtained by polymerizing ethylene. The polyethylene is odorless, nontoxic, has wax-like hand feeling, excellent low-temperature resistance and good chemical stability, and can resist corrosion of most of acid and alkali.

Polypropylene is a semi-crystalline thermoplastic. The polypropylene has high impact resistance, high mechanical property and high toughness, and resists corrosion of various organic solvents and acid and alkali. Has wide application in industry, and is one of common polymer materials.

Polyvinyl chloride (PVC), abbreviated as PVC, has been a common plastic with the largest output in the world and has been widely used. PVC has better mechanical property, high tensile strength, high impact strength and excellent dielectric property.

By adopting the scheme, the type of the thermoplastic plastic is optimized, so that the thermoplastic plastic can be better mixed and reacted with the activated thermosetting plastic, and the heat insulation, wear resistance and insulation performance of the regenerated plastic particles are improved.

The invention is further configured to: the weight ratio of the thermosetting plastic to the thermoplastic plastic is 6-7: 3-4.

by adopting the scheme, the weight ratio of the thermosetting plastic to the thermoplastic plastic is optimized, the weight ratio of the thermosetting plastic is increased in a reasonable range, the weight ratio of the thermoplastic plastic is reduced, the excellent performance of the regenerated plastic particles is not affected, and the recycling efficiency of the thermosetting plastic is improved.

The invention is further configured to: the particle size of the thermosetting plastic after activation treatment is 0.004-0.15 mm.

By adopting the scheme, the particle size of the thermosetting plastic after activation treatment is optimized, the particle size of the thermosetting plastic is further reduced, the number of activated groups of the thermosetting plastic is increased, the reactivity of the thermosetting plastic is improved, the bonding force between the thermosetting plastic and the thermoplastic resin is stronger, and the recycling efficiency of the thermosetting plastic is further improved.

The invention is further configured to: the particle size of the thermoplastic plastic is 3-5 mm.

by adopting the scheme, the particle size of the thermoplastic plastic is optimized, so that the thermoplastic plastic also has high activity, and can be better combined with the active particles of the thermosetting plastic, and further the excellent performance of the regenerated plastic particles is improved.

The second purpose of the invention is that: provides a preparation process of the recycled plastic particles, which comprises the following steps:

(a) Carrying out mechanical physical activation treatment on the thermosetting plastic;

(b) Uniformly mixing the thermosetting plastic, the thermoplastic plastic, the lubricant, the antioxidant, the plasticizer and the coupling agent after activation treatment according to the formula amount, and heating to melt at the heating temperature of 180-190 ℃ to obtain a molten mixture;

(c) and (c) mixing the molten mixture obtained in the step (b) in an extruder for 18-25min at a cutter shaft rotating speed of 500-600rpm/min, and after mixing is finished, extruding, cooling and pelletizing to obtain the regenerated plastic particles.

The activated thermosetting plastic has a large number of mechanical force activated groups, and the active particles have strong reactivity, have strong binding force with the thermoplastic resin and can perform mechanochemical reaction. Under heating, the molten mixture has a chemical reaction process in addition to the physical action, which causes a linking reaction between the molecular structures of the thermosetting plastic and the thermoplastic polymer to form a polymer chain, and the polymer molecules of the two structures are bound together by the action of a 'bridge'. Finally, the thermosetting plastic and the thermoplastic polymer molecules are fused together, and the mutual positions of the molecular structure and the functional groups are kept by the Van der Waals force.

By adopting the scheme, the activated thermosetting plastic and other raw materials are mixed, heated and melted, and then are subjected to mixing, extrusion, cooling, granulation and molding to obtain the regenerated plastic particles. The preparation process method is simple, is suitable for industrial application, and can greatly improve the recycling efficiency of the thermosetting plastic.

The invention is further configured to: the thermosetting plastic activation treatment in the step (a) comprises the following steps:

S1, coarse crushing: firstly, disassembling, cleaning and drying the thermosetting plastic, and then crushing the thermosetting plastic, wherein the particle size of the crushed thermosetting plastic is 2-8 mm;

s2, fine crushing: carrying out secondary crushing on the thermosetting plastic coarsely crushed in the step S1, wherein the particle size is 0.08-0.5mm after crushing;

S3, regeneration: and (3) performing mechanical activation regeneration on the thermosetting plastic after the fine crushing in the step S2, wherein the rotating speed of a cutter shaft is 500-2500rpm/min, the temperature is 60-120 ℃, the time is 50-150min, and the particle size after activation is 0.003-0.2 mm.

The mechanism of mechanical-physical regeneration of thermosetting plastics is as follows: in the coarse crushing and fine crushing stages, the particle size of the thermosetting plastic is reduced, the specific surface area is increased, and thermosetting plastic powder is obtained, but the molecular structure and the chemical property of the reticular cross-linking are not changed. In the regeneration stage, the thermosetting plastic powder is continuously crushed, the particle size is continuously reduced, but the particle size is slowly changed or even is not changed any more, at the moment, under the comprehensive action of mechanical force and heat, the molecular chain fracture process of the thermosetting plastic powder occurs, the crosslinking density is reduced, the reticular crosslinking structure is gradually destroyed, the mechanochemical effect is generated, a large amount of active groups are generated, and the molecular structure and the chemical property are changed.

by adopting the scheme, the mechanical energy is converted into heat energy, so that the chemical bond with weaker bond energy in the molecular structure is promoted to be broken, new functional groups are generated, the active groups are increased, and the reaction activity of the reclaimed materials is enhanced. The heat energy destroys the cross-linking structure of the thermosetting plastic macromolecules, reduces the cross-linking density, generates a low cross-linked high polymer, increases the viscosity and the fluidity of the reclaimed material of the thermosetting plastic, has the capability of reshaping again, improves the mechanical property of the reclaimed plastic, and realizes the recycling of the waste thermosetting plastic.

In conclusion, the invention has the following beneficial effects:

1. in the regenerated plastic particles, the thermosetting plastic is regenerated by a mechanical and physical method to prepare active particles, the active particles of the thermosetting plastic are used as a main material and the thermoplastic plastic is used as an auxiliary material, and then a lubricant, an antioxidant, a plasticizer, a coupling agent and other auxiliary agents are used in a matching manner, so that the regenerated plastic particles have excellent performances of heat insulation, wear resistance, insulation and the like, and the efficiency of recycling the thermosetting plastic is improved;

2. In the regenerated plastic particles, the thermosetting plastic is subjected to three stages of coarse crushing, fine crushing and regeneration, so that new functional groups are generated in the molecular structure of the thermosetting plastic, active groups are increased, and the reaction activity is improved;

3. the preparation process of the regenerated plastic particles is simple, is suitable for industrial application, and can greatly improve the recycling efficiency of the thermosetting plastic.

Detailed Description

The present invention will be described in further detail below.

Example 1

A preparation method of thermosetting plastic activated particles comprises the following steps:

S1, coarse crushing: firstly, disassembling, cleaning and drying the thermosetting plastic, and then crushing the thermosetting plastic, wherein the particle size of the crushed thermosetting plastic is about 2 mm;

S2, fine crushing: carrying out secondary crushing on the thermosetting plastic coarsely crushed in the step S1, wherein the particle size of the crushed thermosetting plastic is about 0.08 mm;

S3, regeneration: and (3) performing mechanical activation regeneration on the thermosetting plastic after the fine crushing in the step S2, wherein the rotating speed of a cutter shaft is 500rpm/min, the temperature is 60 ℃, the time is 150min, and the particle size after activation is about 0.003 mm.

Example 2

S1, coarse crushing: firstly, disassembling, cleaning and drying the thermosetting plastic, and then crushing the thermosetting plastic, wherein the particle size of the crushed thermosetting plastic is about 8 mm;

S2, fine crushing: carrying out secondary crushing on the thermosetting plastic coarsely crushed in the step S1, wherein the particle size of the crushed thermosetting plastic is about 0.5 mm;

S3, regeneration: and (3) performing mechanical activation regeneration on the thermosetting plastic after the fine crushing in the step S2, wherein the rotating speed of a cutter shaft is 2500rpm/min, the temperature is 120 ℃, the time is 50min, and the particle size after activation is about 0.2 mm.

Example 3

s1, coarse crushing: firstly, disassembling, cleaning and drying the thermosetting plastic, and then crushing the thermosetting plastic, wherein the particle size of the crushed thermosetting plastic is about 5 mm;

S2, fine crushing: carrying out secondary crushing on the thermosetting plastic coarsely crushed in the step S1, wherein the particle size of the crushed thermosetting plastic is about 0.3 mm;

s3, regeneration: and (3) performing mechanical activation regeneration on the thermosetting plastic after the fine crushing in the step S2, wherein the rotating speed of a cutter shaft is 2000rpm/min, the temperature is 100 ℃, the time is 100min, and the particle size after activation is about 0.01 mm.

example 4

A method for preparing thermosetting plastic activated particles, which is different from the method of example 3, is that in step S3, the rotating speed of the cutter shaft is adjusted to 2500rpm/min, and the particle size after activation is about 0.004 mm.

Example 5

A method for preparing thermosetting plastic activated particles, which is different from the method of example 3, is that the adjustment time in step S3 is 60min, and the particle size after activation is about 0.15 mm.

comparative example 1

A method for preparing thermosetting plastic activated particles, which is different from the method of example 3, is that the rotation speed of the cutter shaft is adjusted to 200rpm/min in step S3, and the particle diameter after activation is about 1 mm.

Comparative example 2

a method for preparing thermosetting plastic activated particles, which is different from the method of example 3, is that the particle size after activation is about 0.8mm by adjusting the time for 20min in step S3.

Example 6

The recycled plastic particles comprise the following components in parts by weight: 500 parts of activated phenolic plastic, 450 parts of polyethylene, 3 parts of stearic acid, 101010 parts of antioxidant, 2 parts of acetyl triethyl citrate and 6 parts of silane coupling agent;

the phenolic plastic is prepared by the preparation method of the recycled plastic particles provided in example 3; the grain diameter of the polyethylene is 3 mm;

The preparation method comprises the following steps:

(a) Uniformly mixing activated phenolic plastics, polyethylene, stearic acid, an antioxidant 1010, acetyl triethyl citrate and a silane coupling agent according to the formula amount, heating to melt, wherein the heating temperature is 180 ℃, and obtaining a molten mixture;

(b) and (b) mixing the molten mixture obtained in the step (a) in an extruder for 18min at the rotating speed of 600rpm/min, and after the mixing is finished, extruding, cooling and pelletizing to obtain the regenerated plastic particles.

Example 7

The recycled plastic particles comprise the following components in parts by weight: 700 parts of activated phenolic plastic, 300 parts of polyethylene, 8 parts of stearic acid, 10105 parts of antioxidant, 6 parts of acetyl triethyl citrate and 2 parts of silane coupling agent;

The phenolic plastic is prepared by the preparation method of the recycled plastic particles provided in example 3; the grain diameter of the polyethylene is 5 mm;

The preparation method comprises the following steps:

(a) Uniformly mixing activated phenolic plastics, polyethylene, stearic acid, an antioxidant 1010, acetyl triethyl citrate and a silane coupling agent according to the formula amount, heating to melt, wherein the heating temperature is 190 ℃ to obtain a molten mixture;

(b) And (b) mixing the molten mixture obtained in the step (a) in an extruder for 25min at the rotating speed of 500rpm/min, and after the mixing is finished, extruding, cooling and pelletizing to obtain the regenerated plastic particles.

example 8

the recycled plastic particles comprise the following components in parts by weight: 600 parts of activated phenolic plastic, 350 parts of polyethylene, 5 parts of stearic acid, 10108 parts of antioxidant, 4 parts of acetyl triethyl citrate and 4 parts of silane coupling agent;

The phenolic plastic is prepared by the preparation method of the recycled plastic particles provided in example 3; the grain diameter of the polyethylene is 4 mm;

the preparation method comprises the following steps:

(a) uniformly mixing activated phenolic plastics, polyethylene, stearic acid, an antioxidant 1010, acetyl triethyl citrate and a silane coupling agent according to the formula amount, heating to melt, wherein the heating temperature is 185 ℃, and obtaining a molten mixture;

(b) And (b) mixing the molten mixture obtained in the step (a) in an extruder for 20min at the rotating speed of 600rpm/min, and after the mixing is finished, extruding, cooling and pelletizing to obtain the regenerated plastic particles.

Example 9

A recycled plastic pellet, which is different from example 8 in that a phenolic plastic is produced by the method for producing the recycled plastic pellet provided in example 4.

Example 10

A recycled plastic pellet, which is different from example 8 in that a phenolic plastic is produced by the method for producing the recycled plastic pellet provided in example 5.

Example 11

A recycled plastic pellet is distinguished from example 8 in that 700 parts of a phenolic plastic is used after activation treatment.

Example 12

a recycled plastic pellet, which is different from example 8 in that 300 parts of polyethylene.

example 13

A recycled plastic pellet differing from example 8 in that the polyethylene particle size was 8 mm.

Example 14

A recycled plastic pellet differing from example 8 in that the polyethylene particle size was 1 mm.

Example 15

a recycled plastic pellet differing from example 8 in that an equal amount of activated polyurethane plastic replaced an equal amount of phenolic plastic.

Comparative example 3

A recycled plastic pellet, which is different from example 8 in that a phenolic plastic is produced by the method for producing the recycled plastic pellet provided in comparative example 1.

Comparative example 4

A recycled plastic pellet, which is different from example 8 in that a phenolic plastic is produced by the method for producing the recycled plastic pellet as provided in comparative example 2.

Comparative example 5

the recycled plastic particles comprise the following components in parts by weight: 800 parts of activated phenolic plastic, 200 parts of polyethylene, 5 parts of stearic acid, 10108 parts of antioxidant, 4 parts of acetyl triethyl citrate and 4 parts of silane coupling agent; the rest is the same as in example 3.

Examples 6-15 and comparative examples 3-5 provided tests of thermal insulation, wear resistance and insulation properties of recycled plastic granules under the same test methods and test conditions with reference to "determination of temperature of deformation under load for plastics GB/T1634-2004", "determination of abrasion resistance by the Plastic-grinding wheel method according to International Standard ISO 9352-2012", "test methods for insulation resistance, volume resistance System and surface resistivity of solid Electrical insulation" and "test methods for testing solid Electrical insulation" according to the following test methods and test conditions:

TABLE 1

as can be seen from the results of table 1, the regenerated plastic granules provided in example 8 have better thermal insulation performance, abrasion resistance and insulation performance than the test results of the regenerated plastic granules provided in examples 6 to 7 and examples 10 to 15. The experimental result data of the tests of the insulation performance, abrasion resistance and insulation performance of the recycled plastic granules provided in comparative examples 3-5 are clearly not as good as those of example 8.

examples 9 and 10 are compared with example 8, and example 9 is prepared by the method for preparing recycled plastic particles provided in example 4, and the particle size of activated phenolic plastics is about 0.004mm, so that the particle size of activated phenolic plastics is reduced; in example 10, the particle size of the activated phenolic plastic is about 0.15mm, which increases the particle size of the activated phenolic plastic, using the method of preparing recycled plastic particles as provided in example 5. The experimental results of the comparative examples 9-10 and the example 8 show that the experimental result data of the examples 8 and 9 are not very different, which indicates that the reduction of the particle size of the phenolic plastics has little significance for the improvement of the activity of the phenolic plastics, and the particle size of the activated phenolic plastics has influence on the heat insulation performance, the wear resistance performance and the insulation performance of the regenerated plastic particles.

Examples 11 and 12 are compared with example 8, and the weight ratio of the activated phenolic plastics is increased in the adjustment of example 11; the weight ratio of polyethylene was reduced by the adjustment in example 12. It can be seen from the results of the experiments conducted in examples 11 and 12 and example 8 that the weight ratio of the activated thermosetting plastic and the activated thermoplastic plastic has an influence on the heat insulating property, the wear resistance and the insulating property of the recycled plastic particles.

Comparing examples 13 and 14 with example 8, the particle size of the thermoplastic polyethylene is increased by adjusting in example 13, and the particle size is not in the preferred range; in example 13, the particle size of the thermoplastic polyethylene was adjusted to be smaller than the preferable range. It is understood from the experimental results of comparative examples 13 and 14 and example 8 that the particle size of the thermoplastic has an influence on the heat insulating property, wear resistance and insulating property of the recycled plastic particles.

Example 15 compares with example 8, the kind of thermosetting plastic is adjusted in example 15, the test result is not very different from example 8, and the specific kind of thermosetting plastic has slight influence on the heat insulating property, wear resistance and insulating property of the recycled plastic particles.

Comparative examples 3 to 5 are compared with example 8, and in comparative example 3, the particle size of the activated phenolic plastic is about 1mm, which increases the particle size of the activated phenolic plastic, which is prepared by the preparation method of the recycled plastic particles provided in comparative example 1; in comparative example 4, which was prepared by the method for preparing recycled plastic granules as provided in comparative example 5, the particle size of the activated phenolic plastic was about 0.8mm, increasing the particle size of the activated phenolic plastic. The contents of the components of the thermosetting plastic and the thermoplastic plastic in the recycled plastic granules in comparative example 5 were out of the range of protection. Compared with the experimental results of the comparative examples 3 to 5 and the example 8, the increase of the particle size of the activated phenolic plastics can obviously influence the activity of the thermosetting plastic active particles, and further influence the heat insulation performance, the wear resistance and the insulation performance of the regenerated plastic particles; the component content of the thermoset and thermoplastic also has an effect on the thermal insulation, abrasion resistance and insulation properties of the recycled plastic granules.

The above-mentioned embodiments are merely illustrative and not restrictive, and those skilled in the art can modify the embodiments without inventive contribution as required after reading this specification, but only fall within the scope of the claims of the present invention.

Claims

1. A recycled plastic pellet characterized by: the paint comprises the following components in parts by weight: 500-700 parts of thermosetting plastic, 300-450 parts of thermoplastic plastic, 3-8 parts of lubricant, 5-10 parts of antioxidant, 2-6 parts of plasticizer and 2-6 parts of coupling agent;

The particle size of the thermosetting plastic after mechanical and physical activation treatment is 0.003-0.2 mm.

2. recycled plastic granules according to claim 1, characterized in that: the thermosetting plastic comprises one or more of phenolic plastic, polyurethane plastic or epoxy resin.

3. Recycled plastic granules according to claim 1, characterized in that: the thermoplastic comprises one or more of polyethylene, polypropylene or polyvinyl chloride.

4. Recycled plastic granules according to claim 1, characterized in that: the weight ratio of the thermosetting plastic to the thermoplastic plastic is 6-7: 3-4.

5. Recycled plastic granules according to claim 1, characterized in that: the particle size of the thermosetting plastic after activation treatment is 0.004-0.15 mm.

6. Recycled plastic granules according to claim 1, characterized in that: the particle size of the thermoplastic plastic is 3-5 mm.

7. a process for the preparation of recycled plastic granules according to any one of claims 1 to 6, characterized in that it comprises the following steps:

(c) And (c) mixing the molten mixture obtained in the step (b) for 18-25min, wherein the rotating speed of a cutter shaft is 500-600rpm/min, and after mixing is finished, extruding, cooling and granulating to obtain the regenerated plastic particles.

8. The method of recycling plastic granules of claim 7, wherein: the mechanical physical activation treatment of the thermosetting plastic in the step (a) comprises the following steps:

s3, regeneration: and (3) performing mechanical activation regeneration on the thermosetting plastic after the fine crushing in the step S2, wherein the rotation speed of a cutter shaft is 500-2500rpm/min, the temperature is 60-120 ℃, the time is 50-150min, and the particle size after activation is 0.003-0.2 mm.