Environment-friendly odorless high-strength reversion regenerated rubber and preparation method thereof

Abstract

The invention relates to the related technical field of regenerated rubber preparation, and discloses environment-friendly odorless high-strength reversion regenerated rubber and a preparation method thereof.The environment-friendly odorless high-strength reversion regenerated rubber comprises a desulfurization device, a mixing device, a forming device, a vulcanization reversion device and a granulation packaging device which are sequentially connected; the desulfurization device comprises a closed desulfurization tank, a spiral stirring blade arranged on the inner wall of the tank body, and a desulfurization agent quantitative injection module and a temperature control module which are connected with the tank body. By adopting the composite environment-friendly desulfurizer and the sectional temperature control vulcanization process, the production peculiar smell is thoroughly eliminated, the VOCs emission is controlled, and the tensile strength of the regenerated rubber is greatly improved through the cooperation of the multi-directional shearing dispersion mechanism and the sectional vulcanization process, so that the quality and stability of the regenerated rubber are ensured, the requirements of subsequent use and the like are met, and the economic benefit is increased. And continuous production is realized through seamless connection of the devices which are sequentially connected in the system, so that the purpose of reducing the cost by reducing the energy consumption is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field related to the preparation of recycled rubber, in particular to an environmentally friendly, odorless, high-strength and reversion-resistant recycled rubber and a preparation method thereof. Background Art

[0002] Recycled rubber is rubber processed from vulcanized scraps in rubber product production, with a certain plasticity and the ability to be reused, abbreviated as recycled rubber. According to the different waste rubbers used, recycled rubber is divided into types such as outer tire type, inner tire type, and rubber shoe type.

[0003] Most of the existing recycled rubbers adopt high-temperature desulfurization processes, which have problems such as desulfurizing agent pollution and odor problems caused by the release of volatile organic compounds (VOCs), and the mechanical strength of the recycled rubber is significantly reduced. Although attempts have been made to improve the desulfurization process in the prior art, there are still problems such as high equipment energy consumption, poor reinforcement effect due to uneven filler dispersion, and lack of segmented optimization of the vulcanization reversion process. To solve such problems, an environmentally friendly, odorless, high-strength and reversion-resistant recycled rubber and a preparation method thereof are proposed. Summary of the Invention

[0004] The present invention provides an environmentally friendly, odorless, high-strength and reversion-resistant recycled rubber and a preparation method thereof, which solve the problems in the above background art.

[0005] The present invention solves its technical problems by adopting the following technical solutions:

[0006] An environmentally friendly, odorless, high-strength and reversion-resistant recycled rubber preparation system includes a desulfurization device, a mixing device, a forming device, a vulcanization reversion device, and a granulating and packaging device connected in sequence;

[0007] The desulfurization device includes a closed desulfurization tank, spiral stirring blades arranged on the inner wall of the tank, a desulfurizing agent quantitative injection module connected to the tank, and a temperature control module;

[0008] The mixing device includes a twin-rotor internal mixer, an activator feeding port arranged above the internal mixer, and a filler pre-dispersion mechanism, wherein the pre-dispersion mechanism is composed of a multi-directional shear rotor and an ultrasonic vibrating screen;

[0009] The vulcanization reversion device includes a segmented heating box body, at least three independent temperature control zones are arranged in the box body, each zone is connected by a conveyor belt, and a negative pressure exhaust channel is arranged at the top of the box body.

[0010] Preferably, the desulfurizing agent quantitative injection module is connected to the desulfurization tank through a multi-channel metering pump, and a hydraulic-driven discharge valve is arranged at the bottom of the desulfurization tank.

[0011] Preferably, the first temperature control zone of the segmented heating box body is connected to a hot air circulation system, an infrared radiation plate is arranged in the second temperature control zone, and a water-cooled interlayer is arranged in the third temperature control zone.

[0012] Preferably, the granulating and packaging device includes a screw extruder, a crawler-type cooling conveyor connected thereto, and an automatic weighing and sealing machine, and the die head aperture of the screw extruder is adjustable.

[0013] A preparation method of an environment-friendly, odorless and high-strength reverted recycled rubber includes the following steps:

[0014] S1: Put waste rubber particles into a desulfurization device, add a composite environment-friendly desulfurizing agent, and complete desulfurization under dynamic stirring and temperature control conditions;

[0015] S2: The desulfurized rubber material enters a mixing device, an activator and a reinforcing filler are added in sequence, and a mixed rubber is formed after multi-directional shearing and dispersion; S3: The mixed rubber is calendered into a sheet by a forming device and conveyed to a vulcanization reversion device for segmented temperature control treatment;

[0016] S4: The vulcanized and reverted rubber sheet is made into granular finished products through a granulating and packaging device.

[0017] Preferably, the composite environment-friendly desulfurizing agent in S1 is compounded from terpene resin and metal oxide in a mass ratio of 3-5:1.

[0018] Preferably, the segmented temperature control treatment in S3 includes: pre-vulcanization in the first temperature control zone, completion of the main vulcanization reaction in the second temperature control zone, and gradient cooling in the third temperature control zone.

[0019] An environment-friendly, odorless and high-strength reverted recycled rubber, the raw material composition of which includes, by mass: 60-80 parts of waste rubber particles, 3-5 parts of composite environment-friendly desulfurizing agent, 1-2 parts of activator, and 10-15 parts of reinforcing filler.

[0020] The advantages and positive effects of the present invention are: By adopting a composite environment-friendly desulfurizing agent and a segmented temperature-controlled vulcanization process, the production odor is completely eliminated, the VOCs emission is controlled, and through the cooperation of a multi-directional shearing and dispersion mechanism and a segmented vulcanization process, the tensile strength of the recycled rubber is greatly improved, ensuring the quality and stability of the recycled rubber, meeting the requirements of subsequent use, etc. Also, through the seamless connection of the devices connected in sequence within the system, continuous production is achieved, thereby achieving the purpose of reducing energy consumption and cost. Description of the Drawings

[0021] The present invention will be further described below with reference to the drawings and embodiments.

[0022] Figure 1 It is a schematic diagram of the system structure of the present invention.

[0023] The marks in the drawings are described separately as follows:

[0024] 1. Desulfurization device; 11. Enclosed desulfurization tank; 111. Spiral stirring blade; 112. Discharge valve; 12. Desulfurizer metering injection module; 13. Temperature control module;

[0025] 2. Mixing device; 21. Twin-screw internal mixer; 211. Activator feeding port; 22. Filler pre-dispersion mechanism;

[0026] 3. Molding device;

[0027] 4. Vulcanization reversion device; 41. Segmented heating box; 411. First temperature control zone; 412. Second temperature control zone; 413. Third temperature control zone; 42. Conveyor belt; 43. Negative pressure exhaust channel;

[0028] 5. Granulation and packaging device; 51. Screw extruder; 52. Track type cooling conveyor; 53. Automatic weighing and sealing machine. Detailed implementation manners

[0029] Now, the present invention will be further described in detail with reference to the accompanying drawings. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present invention in a schematic manner, so they only show the components related to the present invention.

[0030] The following further details the embodiments of the present invention with reference to the accompanying drawings:

[0031] Refer to Figure 1 As shown, recycled rubber is rubber processed from vulcanized scrap in rubber product production, with a certain plasticity and can be reused, simply referred to as recycled rubber. According to the different waste rubbers used, recycled rubber is divided into types such as outer tire type, inner tire type, and rubber shoe type. Most of the existing recycled rubbers adopt high-temperature desulfurization processes, which have problems such as desulfurizer pollution, odor problems caused by the release of volatile organic compounds (VOCs), and a significant reduction in the mechanical strength of the recycled rubber. Moreover, although attempts have been made to improve the desulfurization process in the prior art, there are still problems such as high equipment energy consumption, poor reinforcement effect due to uneven filler dispersion, and lack of segmented optimization of the vulcanization reversion process. To solve these problems, an environmentally friendly, odorless, high-strength reverted recycled rubber and its preparation method are proposed, including a desulfurization device 1, a mixing device 2, a molding device 3, a vulcanization reversion device 4, and a granulation and packaging device 5 connected in sequence;

[0032] The desulfurization device 1 includes an enclosed desulfurization tank 11, spiral stirring blades 111 provided on the inner wall of the tank, a desulfurizer metering injection module 12 connected to the tank, and a temperature control module 13;

[0033] The mixing device 2 includes a twin-screw internal mixer 21, an activator feeding port 211 provided above the internal mixer, and a filler pre-dispersion mechanism 22, wherein the pre-dispersion mechanism is composed of a multi-directional shear rotor and an ultrasonic vibrating screen;

[0034] The vulcanization reversion device 4 includes a segmented heating box body 41, with at least three independent temperature control zones arranged inside the box body. Each zone is connected by a conveyor belt, and a negative pressure exhaust channel 43 is provided at the top of the box body. By adopting a composite environmental protection desulfurization agent and a segmented temperature control vulcanization process, production odors are completely eliminated, VOC emissions are controlled, and through the cooperation of a multi-directional shearing and dispersing mechanism and a segmented vulcanization process, the tensile strength of the recycled rubber is greatly improved, ensuring the quality and stability of the recycled rubber to meet subsequent usage requirements. Additionally, seamless connection of the devices sequentially connected within the system enables continuous production, thereby achieving the goal of reducing energy consumption and costs.

[0035] It should be noted that the raw material composition of an environmentally friendly odorless high-strength reclaimed rubber in this embodiment includes, by mass: 60 - 80 parts of waste rubber particles, 3 - 5 parts of a composite environmental protection desulfurization agent, 1 - 2 parts of an activator, and 10 - 15 parts of a reinforcing filler.

[0036] Furthermore, the above high strength is mainly reflected in: The mixing device 2 includes a twin-rotor internal mixer 21, an activator feeding port 211 provided above the internal mixer, and a filler pre-dispersion mechanism 22. Among them, the pre-dispersion mechanism is composed of a multi-directional shearing rotor and an ultrasonic vibrating screen. The size of the filler agglomerates is ≤5μm (≥15μm in the traditional process), and the interfacial bonding strength is increased by 30%.

[0037] It should be noted that the following purposes can be achieved through the setting of three-zone temperature control: Pre-vulcanization in the first temperature control zone 411 at 120 - 130°C: Promote the diffusion of sulfur into the rubber matrix; Main vulcanization in the second temperature control zone 412 at 150 - 160°C: Infrared radiation ensures the uniformity of the cross-linking reaction; Gradient cooling in the third temperature control zone 413 at 80 - 100°C: Avoid internal stress cracks caused by sudden cooling.

[0038] It is worth mentioning that the modified clay (lamellar structure) and silica white (nano-particles) are compounded in a ratio of 3:1, forming a three-dimensional network through geometric effects + hydrogen bond interactions, thereby greatly improving the strength of the recycled rubber.

[0039] Moreover, the above "environmentally friendly and odorless" is mainly reflected in that terpene resin (bio-based renewable material) replaces traditional coal tar and toxic desulfurization agents such as dithiocarbamates, and metal oxides such as zinc oxide are used as catalysts, reducing the desulfurization reaction temperature to 150 - 160°C (compared with above 180°C in the traditional process), reducing sulfur-containing waste gas generated by high-temperature cracking, thereby achieving the goal of being environmentally friendly and odorless.

[0040] It should also be noted that the spiral stirring blades 111 of the closed desulfurization tank 11 cooperate with the tank body sealing structure, and together with the negative pressure exhaust channel 43 of the vulcanization reversion device 4, form a closed production chain to effectively collect volatile substances. Additionally, the setting of the above three-stage temperature control zone can also effectively treat the above waste gas.

[0041] Specifically, the hot air circulation system in the pre-vulcanization stage of the first temperature control zone 411 can recover low-concentration VOCs. The infrared radiation plates in the second temperature control zone 412 reduce the vulcanization time and inhibit the generation of odor substances due to side reactions. The water-cooled sandwich in the third temperature control zone 413 rapidly cools down to prevent the continuous release of gases from the high-temperature rubber compound.

[0042] Furthermore, the specific steps of the above method for preparing recycled rubber are as follows. S1: Put waste rubber particles into the desulfurization device 1, add a composite environmental protection desulfurizing agent, and complete desulfurization under dynamic stirring and temperature control conditions.

[0043] S2: The desulfurized rubber compound enters the mixing device 2, and an activator and a reinforcing filler are added in sequence, and a mixed rubber is formed after multi-directional shearing and dispersion.

[0044] S3: The mixed rubber is calendered into a sheet by the forming device 3 and transported to the vulcanization reversion device 4 for segmented temperature control treatment.

[0045] S4: The sheet after vulcanization reversion is made into granular finished products through the granulation and packaging device 5.

[0046] Among them, the composite environmental protection desulfurizing agent described in S1 is compounded from terpene resin and metal oxide in a mass ratio of 3 - 5:1; the segmented temperature control treatment described in S3 includes: pre-vulcanization in the first temperature control zone 411, completion of the main vulcanization reaction in the second temperature control zone 412, and implementation of gradient cooling in the third temperature control zone 413.

[0047] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention is not limited to the embodiments described in the specific implementation manners. Any other implementation manners obtained by those skilled in the art according to the technical solutions of the present invention also fall within the scope of protection of the present invention.

Claims

1. An environmentally friendly, odorless and high-strength reclaimed rubber preparation system, characterized in that: It includes a desulfurization device (1), a mixing device (2), a forming device (3), a vulcanization reversion device (4) and a granulation and packaging device (5) which are connected in sequence; The desulfurization device (1) includes a closed desulfurization tank (11), spiral stirring blades (111) arranged on the inner wall of the tank, a desulfurizing agent quantitative injection module (12) connected to the tank body and a temperature control module (13); The mixing device (2) includes a twin-rotor internal mixer (21), an activator feeding port (211) arranged above the internal mixer and a filler pre-dispersion mechanism (22), wherein the pre-dispersion mechanism is composed of a multi-directional shearing rotor and an ultrasonic vibrating screen in combination; The vulcanization reversion device (4) includes a segmented heating box body (41), at least three independent temperature control zones are arranged in the box body, each zone is connected by a conveyor belt, and a negative pressure exhaust channel (43) is arranged at the top of the box body.

2. The preparation system for an environmentally friendly, odorless, and high-strength reclaimed rubber according to claim 1, characterized in that: The desulfurizing agent quantitative injection module (12) is connected to the desulfurization tank through a multi-channel metering pump, and a hydraulic-driven discharge valve (112) is arranged at the bottom of the desulfurization tank.

3. An environmentally friendly and odorless high-strength reverted and recycled rubber preparation system according to claim 1, characterized in that: The first temperature control zone (411) of the segmented heating box body (41) is connected to a hot air circulation system, an infrared radiation plate is arranged in the second temperature control zone (412), and a water-cooled interlayer is arranged in the third temperature control zone (413).

4. An environmentally friendly and odorless high-strength reclaimed rubber preparation system according to claim 3, characterized in that: The granulation and packaging device (5) includes a screw extruder (51), a crawler-type cooling conveyor (52) connected thereto and an automatic weighing and sealing machine (53), and the die head aperture of the screw extruder (51) is adjustable.

5. The preparation method of the preparation system according to any one of claims 1-4, characterized in that: It includes the following steps: S1: Put waste rubber particles into the desulfurization device (1), add a composite environmental protection desulfurizing agent, and complete desulfurization under dynamic stirring and temperature control conditions; S2: The desulfurized rubber compound enters the mixing device (2), an activator and a reinforcing filler are added in sequence, and a mixed rubber is formed after multi-directional shearing and dispersion; S3: The mixed rubber is calendered into a sheet by the forming device (3) and conveyed to the vulcanization reversion device (4) for segmented temperature control treatment; S4: The vulcanized and reverted film is made into granular finished products through the granulation and packaging device (5).

6. An environmentally friendly, odorless, high-strength reclaimed rubber and its preparation method according to claim 5, characterized in that: The composite environmental protection desulfurizing agent described in S1 is compounded by terpene resin and metal oxide in a mass ratio of 3-5:

1.

7. An environmentally friendly odorless high-strength reverted recycled rubber according to claim 5 and a preparation method thereof, characterized in that: The segmented temperature control treatment described in S3 includes: pre-vulcanization in the first temperature control zone (411), completion of the main vulcanization reaction in the second temperature control zone (412), and implementation of gradient cooling in the third temperature control zone (413).

8. An environmentally friendly odorless high-strength reverted recycled rubber prepared by the method according to any one of claims 5-7, characterized in that: Its raw material composition includes by mass: 60-80 parts of waste rubber particles, 3-5 parts of composite environmental protection desulfurizing agent, 1-2 parts of activator, and 10-15 parts of reinforcing filler.

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