Method for separating metal rubber part by using solvent soaking

Abstract

A method for separating metal and rubber parts through solvent soaking comprises the following steps of S1, rubber aging, S2, metal and rubber part separation and S3, residual rubber cleaning. According to the method, the rubber parts are aged and denatured through a polar solvent, meanwhile, the metal parts cannot be eroded or damaged, the original high elasticity and rigidity of the metal parts cannot be lost, the adhesive force of the metal parts is reduced, and the service life of the metal parts is prolonged. And the energy consumption of mechanical separation is subsequently reduced, and excessive damage to the metal part in mechanical separation is avoided, so that the separation of the rubber part and the recycling of the metal part can be efficiently and reliably realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of low-carbon recycling and remanufacturing of metal-rubber damping devices in rail transit, in particular to a method for separating metal-rubber devices by solvent soaking. BACKGROUND

[0002] In the field of rail transit, there are a large number of metal-rubber composite damping devices in the bogies of locomotives, which provide flexible support for the operation of the locomotives. Common ones include conical springs, spherical hinges (nodes), and cover plates, etc. These metal-rubber devices are generally connected by metal and rubber parts through vulcanization, and the high elasticity and strength of the rubber parts are used to provide certain flexible support and stiffness. These metal-rubber devices are consumable parts and often need to be replaced as a whole after a long time of operation. The aging failure is generally the rubber part, and the metal part still has the value of recycling and remanufacturing. How to efficiently separate the rubber part from the metal-rubber device has a positive significance for the recycling and remanufacturing of the metal part. In the prior art, there are related schemes for stripping the rubber body to recycle the metal part by mechanical means, but since the rubber part cannot achieve the original characteristics, it still has considerable elasticity and stiffness. Direct mechanical stripping consumes a lot of energy and may cause damage to the metal part. Therefore, before directly stripping the rubber part, certain pretreatment is performed on the rubber part to reduce its mechanical strength and adhesion to the metal part, which will be beneficial to the subsequent separation and recycling of the metal part.

[0003] Through retrieval, there are related literatures in the prior art. For example, the publication number is "CN116352923A", and the name is "A recycling process for scrap rubber sealing parts". A recycling process for scrap rubber sealing parts is disclosed, which includes the recovery of scrap rubber parts, the removal of rubber on the iron part, the phosphating of the iron part, and the vulcanization and molding of the rubber. It uses ultrasonic treatment in an alkaline solution to achieve non-destructive stripping of the rubber and the iron part. However, in this scheme, the characteristics of the solvent are beneficial to the denaturation and aging of the rubber, but it causes certain erosion damage to the metal part. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a method for separating metal-rubber devices by solvent soaking, which comprises the following steps: Rubber aging S1, placing the metal-rubber device in a solvent containing a polar solution and anhydrous ethanol to soak, so that the rubber part connected to the metal part by vulcanization in the metal-rubber device is denatured and aged, and loses high elasticity and strength; Metal-rubber device separation S2, using mechanical pressure to press out the rubber part, so that the metal part and the rubber part are separated; Residual glue cleaning S3, cleaning the residual glue attached to the surface of the separated metal part to completely remove the rubber on the surface of the metal part.

[0005] Further, in the solvent containing polar solution and anhydrous ethanol, dichloromethane accounts for 10-20%, dimethylformamide accounts for 10-20%, dimethylacetamide accounts for 10-20%, N-methyl pyrrolidone accounts for 10-20%, and the rest is anhydrous ethanol.

[0006] Further, in the step of rubber aging S1, the metal rubber part is immersed in the solvent containing polar solution and anhydrous ethanol under heating and pressurization.

[0007] Further, the step of pretreatment S0 is further included, in which a pre-stress is applied to the metal part in the metal rubber part and is maintained so that the rubber part is in a tensile and / or shear state, and then the step of rubber aging S1 is performed.

[0008] Further, when the metal rubber part is a spherical hinge, a pretreatment tool is provided, and the pre-stress is applied by using the tool.

[0009] Further, the spherical hinge includes a mandrel, an outer sleeve, a rubber body vulcanized and connected between the mandrel and the outer sleeve, and mounting holes formed at both ends of the mandrel; the pretreatment tool includes a support cylinder with a depth greater than the length of the mandrel, a support ring connected to the inner wall of the support cylinder, and a pair of fixed ears connected to the top of the support cylinder in opposition, a first through slot vertically extending is formed in the fixed ear, and a fixed slot vertically communicated with the first through slot is further formed in the fixed ear.

[0010] Further, the step of pretreatment S0 specifically includes the following steps: Spherical hinge assembly S01, the spherical hinge is vertically placed in the support cylinder, and the end of the outer sleeve abuts against the support ring; Pre-stress application S02, the pressing rod is inserted through the mounting hole at the upper end of the mandrel and the first through slot of the fixed ear, the pressing rod is pressed to the bottom end of the first through slot, and then the fixed plate is inserted into the fixed slot, so that the rubber body is maintained in a compressed state.

[0011] Alternatively, the first through slot of the fixed ear of the pretreatment tool is further connected to a second through slot extending horizontally, the second through slot is connected to a third through slot extending vertically upward at the end, and the extension direction of the second through slot of the fixed ear arranged in opposition is opposite; the inner wall of the support cylinder is further provided with a clamping block that can extend and retract radially along the support cylinder.

[0012] Further, the step of pretreatment S0 specifically includes the following steps: Spherical hinge assembly S01, the spherical hinge is vertically placed in the support cylinder, and the end of the outer sleeve abuts against the support ring, and the clamping block stably clamps the outer wall of the outer sleeve; Prestress is applied S02, the first through slot of the installation hole and the fixed lug on the upper end of the core shaft is penetrated by the pressure rod, the pressure rod is pressed to the bottom of the first through slot, the both ends of the pressure rod are rotated to the second through slot, the pressure rod is rebounded to the third through slot after the pressure rod is released, and the rubber body is maintained in the compressed and sheared state.

[0013] Further, the method further comprises the step of surface treatment S4 of the metal piece, specifically, sand blasting and cleaning are performed on the surface of the metal piece to meet the surface roughness requirement of the subsequent vulcanization production.

[0014] Compared with the prior art, the technical scheme has the following beneficial effects: the method can make the aging denaturation of the rubber piece by using the polar solvent, without causing corrosion and damage to the metal piece, so that the metal piece loses the original high elasticity and stiffness, and the adhesion to the metal piece is reduced, the energy consumption of subsequent mechanical separation is reduced, the excessive damage to the metal piece in the mechanical separation is avoided, and the rubber piece separation and recycling of the metal piece can be efficiently and reliably realized. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 : Assembly of the ball hinge in the pretreatment tool Figure 1 ; Figure 2 : Assembly of the ball hinge in the pretreatment tool Figure 3 : Schematic view of the pressure rod in the left end connecting lug when the ball hinge is pressed and twisted by using the pretreatment tool Figure 4 : Schematic view of the pressure rod in the right end connecting lug when the ball hinge is pressed and twisted by using the pretreatment tool Figure 5 : Schematic view of the ball hinge pressed by using the pretreatment tool. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0017] A method for separating a metal rubber piece by using solvent soaking, comprising the following steps: Rubber aging S1, the metal rubber piece is placed in a solvent containing a polar solution and anhydrous ethanol, the rubber piece vulcanized and connected with the metal piece in the metal rubber piece is denatured and aged, and loses high elasticity and strength; Metal rubber piece separation S2, the rubber piece is pressed out by using a mechanical pressing method, so that the metal piece and the rubber piece are separated; The residual glue is cleaned S3, and the residual glue attached to the surface of the separated metal piece is cleaned to remove all the rubber on the surface of the metal piece.

[0018] The above is the basic step of the method. After the metal rubber piece is placed in a polar solvent environment for a period of time, the aging of the metal rubber piece will be accelerated, and the original high elasticity and strength of the metal rubber piece will be lost. The adhesion of the metal piece will be reduced. After accelerated aging, the rubber piece can be separated without applying excessive mechanical load to the metal piece, and a metal piece with only surface-attached residual glue is obtained. In this process, the metal piece receives less mechanical load, and its loss, damage, and mechanical deformation are smaller, which provides the possibility for subsequent recycling and manufacturing. The residual glue can be cleaned by mechanical methods such as iron brushes. It should be noted that even if the metal piece is less damaged during the separation process, it still has a deformation in size and shape compared to a newly manufactured product. The metal piece can be processed through shaping, compensation, etc. after recycling, and the recycled metal piece can be used in a degraded manner.

[0019] Further, in the solvent containing polar solution and anhydrous ethanol, dichloromethane accounts for 10-20%, dimethylformamide accounts for 10-20%, dimethylacetamide accounts for 10-20%, N-methyl pyridine accounts for 10-20%, and the remaining component is anhydrous ethanol. The polar solvent promoted by this composition can effectively accelerate the denaturation and aging of the rubber piece. Since it is an organic polar solvent, it will not cause any erosion and damage to the metal piece, and it can be recycled and reused.

[0020] In a more preferred embodiment, in the step of rubber aging S1, the metal rubber piece is immersed in a solvent containing polar solution and anhydrous ethanol under heating and pressure.

[0021] In a more preferred embodiment, it further includes a pretreatment step S0 of applying a pre-stress to the metal piece in the metal rubber piece and keeping it, so that the rubber piece is in a tensile and / or shear state, and then the step of rubber aging S1 is performed.

[0022] Although the aging of rubber parts can be accelerated by using polar solvents, most of the rubber parts of metal rubber parts, especially products such as conical springs, spherical hinges, etc., are vulcanized with metal parts, and the exposed part is limited, so the contact area with the solvent is limited. In order to further increase the contact area of the rubber part and the solvent, a certain pre-stress can be applied to the metal part, so that the rubber part is in a non-free state. When the rubber begins to age and denature, its elasticity and strength will decrease, and under the action of pre-stress, the rubber will accelerate cracking and dispersion, thereby increasing the contact area with the solvent. With the increase of reaction time, the adhesion between the metal part and the rubber under this pre-stress will be likely to fail, and the partial separation of the rubber part will be likely to be achieved during the solvent reaction process. It should be noted that in general, the metal rubber damping parts used in vehicles are generally in a free state or a pre-compressed state. This state of the rubber part makes the metal part and the rubber part not have a large pre-stress, so in order to accelerate the aging and separation of the rubber body and increase the reaction contact area, a certain pre-stress needs to be applied additionally.

[0023] In general, the rubber part is in a compressed state after the pre-stress is applied, although the separation of the rubber part can also be accelerated under this pre-stress, but since the separation direction tends to be in the compression direction, the separation effect is still limited. The general compressive mechanical strength of the rubber body is significantly stronger than the tensile and shear strength, and in the metal rubber damping part, the rubber body needs to be in a tensile and / or shear state as much as possible to avoid being in a tensile and / or shear state, otherwise the service life will be significantly reduced. In this embodiment, this characteristic can be used to make the rubber part in a tensile and / or shear state under the pre-stress, and during the aging process, it will be cracked and aged in the tensile and / or shear separation direction under the action of the pre-stress, thereby further increasing the reaction contact area with the solvent.

[0024] In a more preferred embodiment, when the metal rubber part is a spherical hinge 3, a pretreatment tool 4 is provided, and the pre-stress is applied by using the tool.

[0025] Specifically referring to Figure 1 , the spherical hinge 3 comprises a mandrel 31, an outer sleeve 32, a rubber body 33 vulcanized between the mandrel 31 and the outer sleeve 32, and mounting holes 311 formed at both ends of the mandrel 31; the pretreatment tool 4 comprises a support cylinder 41 with a length greater than that of the mandrel 31, a support ring 42 connected to the inner wall of the support cylinder 41, and a pair of fixed ears 43 connected to the top of the support cylinder 41 in opposition, wherein a first through slot 431 vertically extending is formed in the fixed ear 43, and a fixed groove 432 vertically communicating with the first through slot 431 is further formed in the fixed ear 43.

[0026] By using the tool, the step of pretreatment S0 specifically comprises the following steps: The spherical hinge is assembled S01, and specifically referring to Figure 1The ball hinge 3 is vertically placed in the support cylinder 41, and the end of the outer sleeve 32 is in contact with the support ring 42. At this time, the outer sleeve 32 is limited in the axial direction of the ball hinge 3 by the support ring 42, so that when the mandrel 31 is pressed downward, the rubber body 33 is in a stretched state under the action of the downward pressing force.

[0027] The prestress is applied S02, see 2 and Figure 5 The pressing rod 44 is inserted through the mounting hole 311 at the upper end of the mandrel 31 and the first through groove 431 of the fixing lug 43, and then the pressing rod 44 is pressed to the bottom end of the first through groove 431. Then, the fixing plate 434 is inserted into the fixing groove 432, so that the rubber body 33 is maintained in a compressed state. When the rubber body 33 is stretched by pressing the pressing rod 44, the pressing rod 44 can be limited by the fixing plate 434 to prevent it from rebounding under the action of the rubber body 33. At this time, the rubber body 33 will be in a stretched state and will always be maintained.

[0028] Unlike the above embodiment, another embodiment can be seen in Figures 2-4 The bottom of the first through groove 431 of the fixing lug 43 of the front treatment tool 4 is also connected to the second through groove 435 which extends transversely. The end of the second through groove 435 is connected to the third through groove 436 which extends vertically upward. The extension direction of the second through groove 435 of the fixing lug 43 is opposite to that of the other fixing lug 43. The inner wall of the support cylinder 41 is also provided with a clamping block 411 which can extend and retract radially along the support cylinder 41. The clamping block 411 is preferably arc-shaped and can fit the surface of the outer sleeve 32. The clamping block 411 can be driven to extend and retract by the bolts penetrating the cylinder wall of the support cylinder 41 and can press and hold the outer sleeve 32.

[0029] After the tool is used to apply prestress, the rubber body 33 of the ball hinge 3 can be in a stretched and compressed state at the same time. The specific steps are as follows: The ball hinge is assembled S01, see Figure 1 The ball hinge 3 is vertically placed in the support cylinder 41, and the end of the outer sleeve 32 is in contact with the support ring 42. The clamping block 411 is used to stably hold the outer wall of the outer sleeve 32. The prestress is applied S02, see Figures 2-4 The pressing rod 44 is inserted through the mounting hole 311 at the upper end of the mandrel 31 and the first through groove 431 of the fixing lug 43, and then the pressing rod 44 is pressed to the bottom end of the first through groove 431. At this time, the rubber body 33 is in a stretched state under the action of the pressing rod 44. The ends of the pressing rod 44 are rotated to the ends of the second through groove 435. Since the two ends are oppositely arranged to the extension direction of the second through groove 435, the mandrel 31 can be twisted under the action of the pressing rod 44. At this time, the rubber body 33 is further in a shearing state. Since the clamping block 411 stably holds the outer wall of the outer sleeve 32, the outer sleeve 32 will not rotate under the shearing force. Then, the pressing rod 44 is released and rebounds to the end of the third through groove 436. At this time, the pressing rod 44 is limited and maintained. At this time, the rubber body 33 is maintained in a compressed and sheared state.

[0030] On the basis of the above-mentioned embodiments, the method further comprises a step S4 of surface treatment of the metal piece, specifically sandblasting and cleaning the surface of the metal piece to meet the surface roughness requirement for the re-vulcanization production.

Claims

1. A method for separating a metal rubber member by solvent immersion, characterized by, The method comprises the following steps: rubber aging S1, the metal rubber part is immersed in a solvent containing a polar solution and anhydrous ethanol, so that the rubber part connected with the metal part by vulcanization is denatured and aged, losing high elasticity and strength; metal rubber part separation S2, the rubber part is pressed out by a mechanical pressing method, so that the metal part and the rubber part are separated; residual glue cleaning S3, the residual glue attached to the surface of the separated metal part is cleaned, so that the rubber on the surface of the metal part is completely removed.

2. The method for separating a metal rubber member by solvent immersion according to claim 1, wherein In the solvent containing a polar solution and anhydrous ethanol, dichloromethane accounts for 10-20%, dimethylformamide accounts for 10-20%, dimethylacetamide accounts for 10-20%, N-methyl pyridine alkyl ketone accounts for 10-20%, and the remaining component is anhydrous ethanol.

3. The method for separating a metal rubber member by solvent soaking according to claim 2, wherein In the step of rubber aging S1, the metal rubber part is immersed in a solvent containing a polar solution and anhydrous ethanol under heating and pressure.

4. The method for separating a metal rubber member by solvent soaking according to claim 3, wherein Further comprising a pretreatment step S0, a pre-stress is applied to the metal part in the metal rubber part and maintained, so that the rubber part is in a tensile and / or shear state, and then the step of rubber aging S1 is performed.

5. The method for separating a metal rubber member by solvent soaking according to claim 4, wherein When the metal rubber part is a spherical hinge (3), a pretreatment tool (4) is provided, and the pretreatment tool is used to apply the pre-stress.

6. The method for separating a metal rubber member by solvent soaking according to claim 5, wherein The spherical hinge (3) comprises a mandrel (31), an outer sleeve (32), and a rubber body (33) connected between the mandrel (31) and the outer sleeve (32) by vulcanization, and mounting holes (311) are formed at both ends of the mandrel (31); the pretreatment tool (4) comprises a support cylinder (41) with a length greater than that of the mandrel (31), a support ring (42) connected to the inner wall of the support cylinder (41), and a pair of fixed ears (43) connected to the top of the support cylinder (41) in opposition, a first through slot (431) vertically extending is formed in the fixed ear (43), and a fixed slot (432) is vertically connected to the first through slot (431).

7. The method for separating a metal rubber member by solvent soaking according to claim 6, wherein The step of pretreatment S0 specifically comprises the following steps: spherical hinge assembly S01, the spherical hinge (3) is vertically placed in the support cylinder (41), and the end of the outer sleeve (32) abuts against the support ring (42); pre-stress application S02, a pressing rod (44) penetrates the mounting hole (311) at the upper end of the mandrel (31) and the first through slot (431) of the fixed ear (43), and after the pressing rod (44) is pressed to the bottom of the first through slot (431), a fixed plate (434) is inserted into the fixed slot (432), so that the rubber body (33) is maintained in a compressed state.

8. The method for separating a metal rubber member by solvent soaking according to claim 6, wherein The bottom of the first through slot (431) of the fixed ear (43) of the pretreatment tool (4) is further connected to a second through slot (435) extending transversely, the end of the second through slot (435) is connected to a third through slot (436) extending vertically upward, and the extension directions of the second through slots (435) in the fixed ears (43) arranged in opposition are opposite; the inner wall of the support cylinder (41) is further provided with a clamping block (411) which can extend and contract radially along the support cylinder (41).

9. The method for separating a metal rubber member by solvent soaking according to claim 6, wherein The step of pretreatment S0 specifically comprises the following steps: Ball hinge assembly S01, the ball hinge (3) is placed in the support cylinder (41) vertically, the end of the outer sleeve (32) is in contact with the support ring (42), and the clamping block (411) is firmly clamped on the outer wall of the outer sleeve (32); Prestress application S02, the installation hole (311) on the upper end of the mandrel (31) and the first through slot (431) of the fixed lug (43) are penetrated by the pressing rod (44), the pressing rod (44) is pressed to the bottom of the first through slot (431), the ends of the pressing rod (44) are rotated to the ends of the second through slot (435), the pressing rod (44) rebounds to the end of the third through slot (436) after the pressing rod (44) is released, and the rubber body (33) is maintained in a compressed and sheared state.

10. The method for separating a metal rubber member by solvent immersion according to any one of claims 1 to 9, characterized by, It also includes the step of metal part surface treatment S4, which is to sand blast and clean the surface of the metal part to meet the surface roughness requirements for re-vulcanization production.

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