CN114381029A - EPDM (ethylene-propylene-diene monomer) rubber reclaimed material closed-cell secondary foam material and preparation method thereof - Google Patents

Abstract

The invention discloses an EPDM rubber reclaimed material closed-cell secondary foaming material and a preparation method thereof, wherein the EPDM rubber closed-cell secondary foaming material comprises 10-20 parts of EPDM rubber, 130 parts of a mixture B110-one, 2-3 parts of vulcanizing agent sulfur powder, 2-3 parts of a vulcanizing assistant DM, 6-6 parts of a foaming agent AC 40004-6 parts, 6-9 parts of zinc oxide, 40-55 parts of talcum powder and 25-35 parts of paraffin oil, and the mixture B comprises 100 parts of a premixed reclaimed material A and 30-45 parts of carbon black; the premix reclaimed material A comprises 4725P 90-110 parts of EPDM rubber and 90-110 parts of EPDM rubber reclaimed material, and the EPDM rubber reclaimed material are the same in parts by weight; the foaming material solves the difficulty of poor compatibility of the EPDM rubber reclaimed rubber, keeps better elasticity, wear resistance, crack resistance, wet skid resistance, shock resistance/buffering property, heat preservation, cold protection, high temperature performance and sound insulation of the EPDM rubber foaming material, and produces products which are nontoxic, tasteless and pollution-free.

Description

EPDM (ethylene-propylene-diene monomer) rubber reclaimed material closed-cell secondary foam material and preparation method thereof

Technical Field

The invention relates to a foaming material, in particular to an EPDM rubber reclaimed material closed-cell secondary foaming material and a preparation method thereof.

Background

The EPDM rubber is widely applied to various industries along with the maturity of domestic production technology, has better elasticity, wear resistance, crack resistance, wet skid resistance and price advantage as a mainstream rubber species, and has high tensile and tearing strength, good chemical resistance, weather resistance and cold resistance; however, under the condition that the demand of the international society on the exploitation and utilization of global resources is increased, the call for the utilization of the recovered resources is put forward in a dispute, and the corresponding global recovery standard GRS4.0 standard and the global recovery standard RCS2.0 standard are also established, so that the rubber and plastic product production enterprises are restricted from reducing the use amount of the petroleum derivatives of the earth ecological resources. The utilization rate of the waste is improved, and the recycling of resources is improved. And as the demand increases and the price rises year by year, the light weight and the cost reduction are the mainstream development trend. EPDM rubber belongs to rubber materials, reclaimed materials are vulcanized and shaped thermosetting elastomers, poor dispersibility after processing and blending is a great difficulty for foaming materials, and how to improve the process to improve the good dispersibility, the low cost and the good comprehensive physical property, so that the widening of the application range needs to be broken through.

Disclosure of Invention

The embodiment of the application provides an EPDM rubber reclaimed material closed-cell secondary foam material and a preparation method thereof, solves the technical problem that in the prior art, when a foam material mainly comprising EPDM rubber is prepared, the performance of the foam material does not meet the use requirement due to the use of the EPDM rubber reclaimed material, and realizes that the EPDM rubber reclaimed material is applied to the preparation of the foam material and the foam material with excellent performance is obtained.

The embodiment of the application provides an EPDM rubber reclaimed material closed-cell secondary foaming material, which comprises

10-20 parts of EPDM rubber

Mixture B110-

2-3 parts of vulcanizing agent sulfur powder

2-3 parts of vulcanization auxiliary agent DM

Foaming agent AC 40004-6 parts

6-9 parts of zinc oxide

40-55 parts of talcum powder

25-35 parts of paraffin oil

The mixture B comprises 100 parts of a premixed reclaimed material A and 30-45 parts of carbon black;

the premix reclaimed material A comprises 90-110 parts of EPDM rubber 4725P and 90-110 parts of EPDM rubber reclaimed material, and the EPDM rubber reclaimed material are the same in parts by weight.

Further, the preparation method of the premix reclaimed material A comprises the following steps:

step (I): putting the EPDM rubber 4725P, EPDM reclaimed rubber into an internal mixer, pressing down the heavy hammer for a displacement distance of two thirds, after reacting for a period of time, fully pressing down the internal mixer heavy hammer, pressurizing, lifting up the heavy hammer, and turning over; pressing down the banburying heavy hammer again, lifting up the heavy hammer, and repeatedly pressing down the heavy hammer for kneading; continuously filling cooling water for cooling in the kneading process, observing the material temperature of the banburying chamber, and pouring the materials to obtain the banburying material;

step (II): and (3) putting the banburying rubber into an open mill, continuously introducing cooling water into a roller of the open mill, controlling the thickness of the roller, cooling, cutting and standing to obtain a premixed reclaimed material A.

Further, the preparation method of the mixture B comprises the following steps:

step (I): putting the carbon black and the premixed recycled material A into an internal mixer, pressing down a heavy hammer for a displacement distance of two thirds, reacting for a period of time, pressing down the internal mixer heavy hammer completely, pressurizing for a period of time, raising the heavy hammer, and turning over; pressing down the banburying heavy hammer again, lifting up the heavy hammer, and repeatedly pressing down the heavy hammer for kneading; continuously filling cooling water to cool in the kneading process, and pouring to obtain a mixture;

step (II): and (3) putting the mixture into a mill table, continuously introducing cooling water into a roller of an open mill, controlling the thickness of the roller, thinning, cooling, cutting and standing to obtain a mixed rubber material B.

A preparation method of an EPDM rubber reclaimed material closed-cell secondary foaming material comprises the following steps:

step (I): putting talcum powder, zinc oxide and paraffin oil into an internal mixing chamber, stirring for a period of time without pressing a heavy hammer, putting B, EPDM rubber into the mixture, pressurizing, lifting the heavy hammer, and turning over; pressing down the banburying heavy hammer again, lifting up the heavy hammer, and repeatedly pressing down the heavy hammer for kneading; adding vulcanizing agent sulfur powder, vulcanizing assistant DM, foaming agent and a pressurizing heavy hammer, after a period of time, raising the heavy hammer, repeatedly pressing down the heavy hammer kneading step for multiple times, continuously filling cooling water in the kneading process to cool, and pouring to obtain a rubber compound;

step (II): putting the rubber compound in the last step into an open mill, continuously introducing cooling water into a roller of the open mill, controlling the thickness of the roller, thinning, cooling, cutting and standing to obtain a mixture C;

step (three): putting the mixture C obtained in the previous step into a calender again, continuously introducing cooling water into a roller of the calender, controlling the thickness of the roller, carrying out thickness calendering, standing and cooling to obtain a rubber compound;

step (IV): putting the rubber compound in the last step into an open mill, controlling the temperature at 80-90 ℃, and open milling to further mix and pre-heat the raw materials of each component to obtain a pre-heating material;

step (V): putting the preheated material in the last step into an extruder for extrusion molding, cutting, standing and cooling to obtain a rubber sheet;

step (six): filling the rubber sheet obtained in the previous step into a primary vulcanizing machine mold for foaming and releasing pressure to obtain a primary vulcanized foaming material;

step (seven): filling the primary vulcanized foaming material into a foaming machine die for foaming, and releasing the pressure to obtain a secondary foaming material;

and (eight): naturally cooling the secondary foaming material at room temperature, and warehousing or processing and molding after the product is sufficiently cooled and contracted.

One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

1. the EPDM rubber reclaimed material is doped with impurities (such as EVA and PE), so that the uniform mixing of the EPDM rubber main material and the EPDM rubber reclaimed material is further improved by preparing the premixed reclaimed material A and the mixed material B, and the dispersibility of the system is improved.

2. PE, EVA etc. are thermoplastic elastomer, and EPDM rubber is thermosetting elastomer, this application is through carrying out the preliminary treatment to EPDM rubber reclaimed materials, utilize the difference that the melting point is different of raw materials such as various thermoplastic elastomer EVA is solved to high temperature in the premix stage, solve simultaneously that some filler in time gets into and has reserved some filler in the raw materials molecular chain under the different melting points, modified the raw materials in advance can thoroughly mix with EPDM rubber, banburying temperature when vulcanizing agent and foamer are added to the back end is not high when premixing, it is also relatively short during banburying, be unlikely to vulcanize in advance in the banburying stage, foaming. The compatibility and the dispersibility are ensured, and scorching and vulcanization foaming in an internal mixing and mixing stage are avoided, so that a normal scorching period, cross-linking molding, uniform foaming nuclei and uniform and consistent pore size and foaming multiplying power in a vulcanization foaming stage after extrusion are ensured.

3. The fineness of the milled powder of the reclaimed EPDM rubber material is less than or equal to 0.074mm, the specific surface area of the milled powder particles can be increased, the number of the fillers in the rubber molecules is increased, the gaps are increased and densified, and the resilience of the EPDM rubber is improved, so that the better lower compression deformation rate of the product can be still kept under the condition that the total main colloid is replaced by the reclaimed EPDM rubber material by about 10-20%. Since the recycled abrasive powder using EPDM rubber as the main material is the thermoset elastomer particles after vulcanization and foaming, namely the main rubber amount in the system is reduced, the corresponding amounts of the vulcanizing agent, the vulcanization auxiliary agent and the foaming agent can be reduced to about 10-20% of the main rubber without EPDM rubber recycled material. However, the EPDM rubber reclaimed material has the heat preservation and insulation characteristics of the foaming material, so the amounts of the foaming auxiliary agent and the heat conduction auxiliary agent zinc oxide need to be increased by about 10-20% of the main rubber of the EPDM rubber reclaimed material.

4. The EPDM rubber reclaimed material can replace the main rubber to be used, the using amount of the main rubber is reduced, meanwhile, a small amount of vulcanized thermoplastic elastomers (EVA and PE) exist in the EPDM rubber reclaimed material, the vulcanized thermoplastic elastomers can reinforce a reaction system, but the vulcanized thermoplastic elastomers are easy to slip when encountering paraffin oil, so that the system is non-uniformly dispersed, and the dispersibility is improved in advance by premixing the reclaimed material A.

5. The foaming material has the advantages that the physical properties of the foaming material are close to those of an EPDM rubber foaming material without the recycled material, the cost is lower, and the price is low, so that the recycled EPDM rubber material and the premixed recycled material A are particularly increased through the mixing and milling; the mixture B is mixed with powder, vulcanization and foaming agent to obtain mixed rubber C, and the mixed rubber C is extruded and molded, foamed once or twice to form foamed material containing 10-20% of EPDM rubber reclaimed material, so that the problem of poor compatibility of the EPDM rubber reclaimed material is solved, the good elasticity, wear resistance, crack resistance, wet skid resistance, shock resistance/buffering property, heat preservation, cold protection, low temperature performance and sound insulation of the EPDM rubber foamed material are maintained, and the produced product is non-toxic, odorless and pollution-free.

Detailed Description

In order to better understand the technical solutions, the technical solutions will be described in detail with reference to the description and the specific embodiments.

Example 1

A preparation method of an EPDM rubber reclaimed material closed-cell secondary foaming material comprises the following steps:

the first-stage banburying premixing process comprises the following steps:

step one, mixing by a 75L rhombic blade shaft W-shaped heavy hammer internal mixer: putting 100 parts of reclaimed EPDM rubber and 100 parts of EPDM rubber into an internal mixer, pressing down a heavy hammer for two thirds of displacement distance to coarsely mix the EPDM rubber and the reclaimed EPDM rubber, avoiding the reclaimed powder from overflowing out of the internal mixing chamber, pressing down all the internal mixing heavy hammers after 320 seconds, pressurizing to 7 kilograms, timing for 320 seconds, lifting up the heavy hammers for 20 seconds, and turning over the coarsely mixed material in the whole internal mixing chamber; pressing down the banburying weight hammer for 200 seconds again, lifting up the banburying weight hammer for 20 seconds, and repeating the pressing down weight hammer kneading step for 6 times (200 seconds/time); continuously filling cooling water of 10 ℃ into the stirring blade shaft and the heavy hammer for cooling in the kneading process, observing the material temperature of the banburying chamber until the temperature reaches 135 ℃, and pouring the material to obtain the dense rubber;

step two, 18 inches of automatic material turning and open milling, namely, putting the banburying rubber obtained in the step one into an open mill, continuously introducing cooling water with the water temperature of 10 ℃ into a roller of the open mill, controlling the thickness of the roller to be 1mm, reducing the temperature of rubber materials to 85 ℃, floating, stacking, cutting and standing for 48 hours according to the weight part of the formula to obtain a premixed reclaimed material A;

step three, mixing by a diamond blade shaft W-shaped heavy hammer internal mixer of 75L: putting 34.96 parts of carbon black and 100 parts of premixed recycled material A into an internal mixer, pressing down a heavy hammer by two thirds of displacement distance to coarsely mix the powder, the EPDM rubber and the premixed recycled material A, so as not to overflow the powder into the internal mixing chamber, pressing down the whole internal mixing heavy hammer by 320 seconds, pressurizing to 7 kilograms, timing for 250 seconds, lifting up the heavy hammer for 20 seconds, and turning over the coarsely mixed material in the whole internal mixing chamber; pressing down the banburying weight hammer for 200 seconds again, lifting up the banburying weight hammer for 20 seconds, and repeating the pressing down weight hammer kneading step for 6 times (200 seconds/time); continuously filling cooling water of 10 ℃ into the stirring blade shaft and the heavy hammer for cooling in the kneading process, observing the material temperature of the banburying chamber until the temperature reaches 138 +/-5 ℃, and pouring the materials to obtain a mixture;

step four, 18 inches of automatic material turning and open milling, putting the mixture obtained in the step three into an open mill, continuously introducing cooling water with the water temperature of 10 ℃ into a roller of the open mill, controlling the thickness of the roller to be 1mm, thinning for 3 times, reducing the temperature of the rubber material to 85 +/-5 ℃, floating, stacking, cutting and standing for 48 hours according to the weight part of the formula to obtain premixed rubber material B;

step five, mixing 46.2 parts of talcum powder, 6.9 parts of zinc oxide and 30 parts of paraffin oil in a mixing chamber by using a W-shaped heavy hammer mixer with a diamond blade shaft of 75L, stirring the blade shaft for 2 minutes without pressing the heavy hammer, then adding 124.7 parts of premixed rubber material B and 13.8 parts of EPDM rubber into the mixer, pressurizing to 7 kg, timing for 350 seconds, lifting the heavy hammer for 20 seconds, and turning over the coarse mixture in the whole mixing chamber; pressing down the banburying weight hammer for 200 seconds again, lifting up the banburying weight hammer for 20 seconds, and repeating the pressing down weight hammer kneading step for 4 times (200 seconds/time); observing the material temperature of the mixing chamber until the temperature is 110 ℃, adding 2.3 parts of vulcanizing agent sulfur powder, 2.3 parts of vulcanizing assistant DM and 4.6 parts of foaming agent pressurizing heavy hammer, rising the heavy hammer after 120 seconds, staying the heavy hammer for 15 seconds, repeating the step of kneading the heavy hammer for 3 times (120 seconds/time), continuously filling 10 ℃ cooling water into the stirring vane shaft and the heavy hammer to cool down in the kneading process, observing the material temperature of the mixing chamber until the material is poured at 130 +/-5 ℃, and obtaining mixed rubber;

step six, 18 inches of automatic material turning and open milling, namely, putting the mixed rubber obtained in the step five into an open mill, continuously introducing cooling water with the water temperature of 10 ℃ into a roller of the open mill, controlling the thickness of the roller to be 1mm, thinning for 3 times, reducing the temperature of the rubber material to 80 +/-5 ℃, rolling by four rollers, floating, stacking, cutting and standing for 48 hours according to the weight part of the formula to obtain a mixed material C;

rolling and standing the mixture C obtained in the step six by a 16-inch four-roll calender, putting the mixture C into the 16-inch four-roll calender again, continuously introducing cooling water with the water temperature of 10 ℃ into a roller of the calender, controlling the thickness of the roller to be 1mm, rolling the roller to be 1mm, standing and cooling for 24 hours to obtain rubber compound;

and (3) second-stage extrusion process:

step eight 18 inches automatic material turning open mill 6mm thick open mill put the mixed rubber of step seven into the open mill, the temperature is controlled at 85 plus or minus 5 ℃, open mill 600 seconds, make each component raw materials further mix and preheat, get the material of preheating;

step nine 250 diameter aspect ratio 1: 8, extruding by a hot-feeding single-screw extruder at the speed of 2-3 meters per minute, controlling the temperature of a screw to be 85 +/-5 ℃, and controlling the temperature of an outlet of a die cavity of the extruder to be 95 ℃; putting the preheated material obtained in the step eight into an extruder, extruding, molding, cutting into rubber sheets meeting the size and weight of a mold, and standing and cooling for 4 hours to obtain material sheets;

and a third stage: and (3) vulcanization foaming molding stage:

step ten-die internal-closing hole foaming, precisely weighing the material sheet after standing in the step nine, filling the material sheet into a corresponding 1300-ton oil pressure primary vulcanizing machine die for foaming, releasing pressure, and obtaining a primary vulcanized foaming material and trimming the material sheet;

and step eleven, filling the primary vulcanized foaming material into a corresponding 300-ton foaming machine for foaming, wherein the foaming temperature is 165 +/-5 ℃ for 45 minutes, and releasing the pressure to obtain the secondary foaming material.

And step twelve, naturally cooling the secondary foaming body for 12-15 days at room temperature, and warehousing or processing and molding after the product is fully cooled and contracted.

Example 2

A preparation method of an EPDM rubber reclaimed material closed-cell secondary foaming material comprises the following steps:

the first-stage banburying premixing process comprises the following steps:

step one, mixing by a 75L rhombic blade shaft W-shaped heavy hammer internal mixer: firstly putting 100 parts of reclaimed EPDM rubber and 100 parts of EPDM rubber into an internal mixer, pressing down a heavy hammer for two thirds of displacement distance to coarsely mix the EPDM rubber and the reclaimed EPDM rubber, avoiding the reclaimed powder from overflowing out of the internal mixing chamber, pressing down all the internal mixing heavy hammers after 320 seconds, pressurizing to 7 kilograms, timing for 320 seconds, lifting up the heavy hammers for 20 seconds, and turning over the coarsely mixed material in the whole internal mixing chamber; pressing down the banburying weight hammer for 200 seconds again, lifting up the banburying weight hammer for 20 seconds, and repeating the pressing down weight hammer kneading step for 6 times (200 seconds/time); continuously filling cooling water of 10 ℃ into the stirring blade shaft and the heavy hammer for cooling in the kneading process, observing the material temperature of the banburying chamber until the temperature reaches 135 ℃, and pouring the material to obtain the dense rubber;

and step two, 18 inches of automatic material turning and open milling, namely putting the banburying rubber in the step one into an open mill, continuously introducing cooling water with the water temperature of 10 ℃ into a roller of the open mill, controlling the thickness of the roller to be 1mm, reducing the temperature of the rubber material to 85 ℃, floating, stacking, cutting and standing for 48 hours according to the weight part of the formula to obtain the premixed reclaimed material A.

Step three, mixing 45 parts of carbon black and 100 parts of premixed recycled material A in a rhombic blade shaft W-shaped heavy hammer internal mixer, pressing down the heavy hammer for two thirds of displacement distance to coarsely mix the powder, the EPDM rubber and the premixed recycled material A, avoiding the powder from overflowing out of an internal mixing chamber, pressing down the whole internal mixing heavy hammer after 320 seconds, pressurizing to 7 kilograms, timing for 250 seconds, lifting the heavy hammer for 20 seconds, and turning over the coarse mixed material in the whole internal mixing chamber; pressing down the banburying weight hammer for 200 seconds again, lifting up the banburying weight hammer for 20 seconds, and repeating the pressing down weight hammer kneading step for 6 times (200 seconds/time); continuously filling cooling water of 10 ℃ into the stirring blade shaft and the heavy hammer for cooling in the kneading process, observing the material temperature of the banburying chamber until the temperature reaches 135 ℃, and pouring the materials to obtain a mixture;

and step four, 18 inches of automatic material turning and open milling, putting the mixture obtained in the step three into an open mill, continuously introducing cooling water with the water temperature of 10 ℃ into a roller of the open mill, controlling the thickness of the roller to be 1mm, thinning for 3 times, reducing the temperature of the rubber material to 85 ℃, floating, stacking, cutting and standing for 48 hours according to the weight part of the formula to obtain a mixture B.

Step five, mixing 55 parts of talcum powder, 9 parts of zinc oxide and 35 parts of paraffin oil in an internal mixing chamber by using a W-shaped heavy hammer internal mixer with a diamond blade shaft of 75L, stirring the blade shaft for 2 minutes without pressing a heavy hammer, then adding 130 parts of mixture B and 20 parts of EPDM rubber into the internal mixer, pressurizing to 7 kg, timing for 350 seconds, raising the heavy hammer for 20 seconds, and turning over the coarse mixture in the whole internal mixing chamber; pressing down the banburying weight hammer for 200 seconds again, lifting up the banburying weight hammer for 20 seconds, and repeating the pressing down weight hammer kneading step for 4 times (200 seconds/time); and (3) observing the material temperature of the mixing chamber until the temperature is 115 ℃, adding 3 parts of vulcanizing agent sulfur powder, 3 parts of vulcanizing additive DM and 6 parts of foaming agent pressurizing heavy hammer, rising the heavy hammer after 120 seconds, staying the heavy hammer for 15 seconds, repeating the pressing down heavy hammer kneading step for 3 times (120 seconds/time), continuously filling 10 ℃ cooling water into the stirring blade shaft and the heavy hammer in the kneading process for cooling, and observing the material temperature of the mixing chamber until the material is poured at 135 ℃.

Putting the mixed rubber obtained in the step five into an open mill for open milling by using an 18-inch automatic material turning open mill, continuously introducing cooling water with the water temperature of 10 ℃ into a roller of the open mill, controlling the thickness of the roller to be 1mm, thinning for 3 times, reducing the temperature of rubber materials to 88 ℃, rolling, stacking, cutting and standing for 48 hours by using four rollers according to the weight part of the formula to obtain a mixed rubber C;

rolling and standing the mixture C obtained in the step six by a 16-inch four-roll calender, putting the mixture C into the 16-inch four-roll calender again, continuously introducing cooling water with the water temperature of 10 ℃ into a roller of the calender, controlling the thickness of the roller to be 1mm, rolling the roller to be 1mm, standing and cooling for 24 hours to obtain rubber compound;

and (3) second-stage extrusion process:

step eight 18 inches automatic material turning open mill 6mm thick open mill put the mixed rubber of step seven into the open mill, the temperature is controlled at 89 ℃, open mill 600 seconds, make each component raw materials further mix and preheat, get the material of preheating;

step nine 250 diameter aspect ratio 1: 8, extruding by a hot-feeding single-screw extruder at the speed of 2-3 meters per minute, controlling the temperature of a screw at 88 ℃ and controlling the temperature of an outlet of a die cavity of the extruder at 93 ℃; putting the preheated material obtained in the step eight into an extruder, extruding, molding, cutting into rubber sheets meeting the size and weight of a mold, and standing and cooling for 4 hours to obtain material sheets;

and a third stage: and (3) vulcanization foaming molding stage:

step ten-die internal-closing hole foaming, precisely weighing the material sheet after standing in the step nine, filling the material sheet into a corresponding 1300-ton oil pressure once-vulcanizing machine for foaming at the foaming temperature of 152 ℃ for 43 minutes, releasing the pressure, and obtaining a once-vulcanized foaming material and trimming the material sheet;

step eleven, filling the primary vulcanized foaming material into a corresponding 300-ton foaming machine for foaming at 168 ℃ for 43 minutes, and releasing pressure to obtain a secondary foaming material;

and step twelve, naturally cooling the secondary foaming material at room temperature for 12-15 days, and warehousing or processing and molding after the product is sufficiently cooled and contracted.

Experimental testing

The physical properties of the finished products obtained in example 1 and example 2 were tested, and the experimental results are shown in the following table, wherein table 1 is the experimental data of example 1, and table 2 is the experimental data of example 2:

TABLE 1

TABLE 2

The above description is only an embodiment utilizing the technical content of the present disclosure, and any modification and variation made by those skilled in the art can be covered by the claims of the present disclosure, and not limited to the embodiments disclosed.

Claims (4)

1. An EPDM rubber reclaimed material closed-cell secondary foaming material is characterized by comprising

10-20 parts of EPDM rubber

Mixture B110-

2-3 parts of vulcanizing agent sulfur powder

2-3 parts of vulcanization auxiliary agent DM

Foaming agent AC 40004-6 parts

6-9 parts of zinc oxide

40-55 parts of talcum powder

25-35 parts of paraffin oil

The mixture B comprises 100 parts of a premixed reclaimed material A and 30-45 parts of carbon black;

the premix reclaimed material A comprises 90-110 parts of EPDM rubber 4725P and 90-110 parts of EPDM rubber reclaimed material, and the EPDM rubber reclaimed material are the same in parts by weight.

2. The EPDM recycled rubber closed-cell secondary foaming material as recited in claim 1, wherein the preparation method of the premixed recycled material A comprises the following steps:

step (I): putting the EPDM rubber 4725P, EPDM reclaimed rubber into an internal mixer, pressing down the heavy hammer for a displacement distance of two thirds, after reacting for a period of time, fully pressing down the internal mixer heavy hammer, pressurizing, lifting up the heavy hammer, and turning over; pressing down the banburying heavy hammer again, lifting up the heavy hammer, and repeatedly pressing down the heavy hammer for kneading; continuously filling cooling water for cooling in the kneading process, observing the material temperature of the banburying chamber, and pouring the materials to obtain the banburying material;

step (II): and (3) putting the banburying rubber into an open mill, continuously introducing cooling water into a roller of the open mill, controlling the thickness of the roller, cooling, cutting and standing to obtain a premixed reclaimed material A.

3. The EPDM recycled rubber closed-cell secondary foaming material as recited in claim 1, wherein the preparation method of the mixture B comprises the following steps:

step (I): putting the carbon black and the premixed recycled material A into an internal mixer, pressing down a heavy hammer for a displacement distance of two thirds, reacting for a period of time, pressing down the internal mixer heavy hammer completely, pressurizing for a period of time, raising the heavy hammer, and turning over; pressing down the banburying heavy hammer again, lifting up the heavy hammer, and repeatedly pressing down the heavy hammer for kneading; continuously filling cooling water to cool in the kneading process, and pouring to obtain a mixture;

step (II): and (3) putting the mixture into a mill table, continuously introducing cooling water into a roller of an open mill, controlling the thickness of the roller, thinning, cooling, cutting and standing to obtain a mixed rubber material B.

4. A preparation method of an EPDM rubber reclaimed material closed-cell secondary foaming material is characterized by comprising the following steps:

step (I): putting talcum powder, zinc oxide and paraffin oil into an internal mixing chamber, stirring for a period of time without pressing a heavy hammer, putting B, EPDM rubber into the mixture, pressurizing, lifting the heavy hammer, and turning over; pressing down the banburying heavy hammer again, lifting up the heavy hammer, and repeatedly pressing down the heavy hammer for kneading; adding vulcanizing agent sulfur powder, vulcanizing assistant DM, foaming agent and a pressurizing heavy hammer, after a period of time, raising the heavy hammer, repeatedly pressing down the heavy hammer kneading step for multiple times, continuously filling cooling water in the kneading process to cool, and pouring to obtain a rubber compound;

step (II): putting the rubber compound in the last step into an open mill, continuously introducing cooling water into a roller of the open mill, controlling the thickness of the roller, thinning, cooling, cutting and standing to obtain a mixture C;

step (three): putting the mixture C obtained in the previous step into a calender again, continuously introducing cooling water into a roller of the calender, controlling the thickness of the roller, carrying out thickness calendering, standing and cooling to obtain a rubber compound;

step (IV): putting the rubber compound in the last step into an open mill, controlling the temperature at 80-90 ℃, and open milling to further mix and pre-heat the raw materials of each component to obtain a pre-heating material;

step (V): putting the preheated material in the last step into an extruder for extrusion molding, cutting, standing and cooling to obtain a rubber sheet;

step (six): filling the rubber sheet obtained in the previous step into a primary vulcanizing machine mold for foaming and releasing pressure to obtain a primary vulcanized foaming material;

step (seven): filling the primary vulcanized foaming material into a foaming machine die for foaming, and releasing the pressure to obtain a secondary foaming material;

and (eight): naturally cooling the secondary foaming material at room temperature, and warehousing or processing and molding after the product is sufficiently cooled and contracted.