A fastener backing plate and a preparation method thereof

Abstract

The present invention provides a fastener backing plate and a preparation method thereof. The fastener backing plate comprises a polyethylene plate and a rubber layer. The polyethylene plate is connected to the rubber layer. A grafting layer is provided on one side of the polyethylene plate facing the rubber layer. The rubber layer comprises chitosan microspheres, and the chitosan microspheres are uniformly dispersed in the rubber layer. The grafting layer is respectively connected to the rubber layer and the chitosan microspheres on the surface layer of the rubber layer. The present invention enables the polyethylene plate to not only be vulcanized and connected to the rubber layer through the grafting layer, but also generate van der Waals forces with the chitosan microspheres on the surface layer of the rubber layer, which can effectively improve the bonding strength between the polyethylene plate and the rubber layer. At the same time, chitosan plays an antibacterial and bactericidal role inside the rubber layer and between the rubber layer and the polyethylene plate. On the one hand, it inhibits the corrosion and decomposition of the rubber layer by bacteria, which is beneficial to delaying the aging of the rubber. On the other hand, it is beneficial to maintaining good bonding strength between the polyethylene plate and the rubber layer for a long time.

Description

Technical Field

[0001] The present invention relates to the technical field of track fasteners, and particularly relates to a fastener backing plate and a preparation method thereof. Background Art

[0002] Currently, in the field of rail transit technology, when the temperature span in the area where the railway bridge is located is large, in order to reduce the interaction force between the bridge structure and the long welded rail on the bridge, it is required that the longitudinal resistance of the track fastener to the rail is small. To meet this requirement, small-resistance fasteners are often used in elevated track lines. When the rail undergoes displacement within a certain range, the small-resistance fastener allows this rail movement, thereby releasing the interaction force between the bridge and the rail.

[0003] In the prior art, a fastener backing plate with small resistance is often used as the under-rail backing plate to reduce the friction coefficient with the rail, thereby reducing the sliding friction force between the two. With the development of the prior art, the traditional stainless steel-rubber composite backing plate has gradually been replaced by a non-metal plate-elastic layer composite backing plate. The latter has obvious advantages in terms of anti-corrosion of the non-metal plate and improving the service life of the overall backing plate. The composite processing technology in the prior art is often relatively simple and difficult to ensure the connection strength between the non-metal plate and the elastic layer. In the environment of train dynamic load, the non-metal plate and the elastic layer are prone to separation, causing the backing plate to be crushed or delaminated, bringing certain potential safety hazards to train operation. Summary of the Invention

[0004] In view of this, the present invention aims to provide a fastener backing plate and a preparation method thereof to solve the problem that the non-metal plate and the elastic layer are prone to separation in the prior art.

[0005] To achieve the above object, the technical solution of the present invention is realized as follows:

[0006] A fastener backing plate includes a polyethylene plate and a rubber layer. The polyethylene plate is connected to the rubber layer. A grafting layer is provided on the side of the polyethylene plate facing the rubber layer. The rubber layer includes chitosan microspheres, and the chitosan microspheres are uniformly dispersed in the rubber layer. The grafting layer is respectively connected to the rubber layer and the chitosan microspheres on the surface layer of the rubber layer.

[0007] Further, the rubber layer includes conductive fillers, and the conductive fillers are uniformly dispersed in the rubber layer. The chitosan microspheres are chitosan microspheres coated with piezoelectric ceramics.

[0008] A preparation method of a fastener backing plate, used to prepare the described fastener backing plate; the preparation method includes: S1. Perform two-stage surface treatment on a polyethylene plate to form a grafted layer on the polyethylene plate; S2. Prepare chitosan microspheres; S3. Knead rubber material and chitosan microspheres in a mixer to obtain a mixed rubber material; S4. Place the mixed rubber material on the grafted layer, and perform integral vulcanization on the grafted layer of the polyethylene plate and the mixed rubber material to obtain the fastener backing plate; the two-stage surface treatment includes a mechanical surface treatment process and a surface grafting treatment process carried out in sequence.

[0009] Further, in step S2, the chitosan microspheres are chitosan microspheres coated with piezoelectric ceramics.

[0010] Further, the mechanical surface treatment process is to use a grinding machine to grind the surface to be treated of the polyethylene plate, so that the surface roughness of the surface to be treated reaches more than 45 μm, and blow the surface to be treated of the polyethylene plate clean with compressed air to form a rough surface of the polyethylene plate; the surface grafting treatment process is: under the state of ultraviolet light irradiation, immerse the rough surface of the polyethylene plate into a benzophenone-acrylic acid solution, take out the polyethylene plate after soaking for 15 minutes, and then use acetone to clean and dry the rough surface of the polyethylene plate to obtain a polyethylene plate with a grafted layer.

[0011] Further, step S2 includes: S21. Add nano-level piezoelectric ceramics into ethanol, stir evenly and then disperse ultrasonically, then add diethanolamine, stir evenly to obtain a piezoelectric ceramic suspension, filter and then dry and grind the precipitate to obtain modified piezoelectric ceramics; S22. Add the modified piezoelectric ceramics into ethanol, stir evenly and then disperse ultrasonically to obtain a 0.01 g / mL modified piezoelectric ceramic suspension; S23. Add chitosan into a 1% acetic acid aqueous solution by mass fraction, stir evenly to obtain a 0.016 g / mL chitosan solution; S24. Stir and mix evenly the modified piezoelectric ceramic suspension prepared in step S22 and the chitosan solution prepared in step S23 according to a volume ratio of 1:1 to obtain a mixed solution A; S25. Add propylene glycol fatty acid ester into liquid paraffin, stir and mix evenly to obtain a mixed solution B; S26. Under a constant temperature water bath at 50 °C, dropwise add the mixed solution A into the mixed solution B, stir evenly to obtain a mixed solution C; S27. After quenching the mixed solution C in an ice-water bath, take it out and then heat the mixed solution C to 30 °C, add glutaraldehyde with a volume fraction of 1.8%, and stir constantly at a constant temperature for 5 h to obtain a chitosan microsphere emulsion coated with piezoelectric ceramics; S28. After centrifuging, filtering, washing and drying the emulsion prepared in step S27, obtain chitosan microspheres coated with piezoelectric ceramics.

[0012] Further, step S3 includes: S31. By weight, put 100 parts of natural rubber compound into an internal mixer for plasticizing. The plasticizing temperature is 90 - 110°C, the rotation speed is 30 - 40 revolutions per minute, and plasticize for 3 - 4 minutes; S32. Add 5 - 8 parts of vulcanization activator, 0.5 - 1.6 parts of scorch retarder, and 8 - 13 parts of conductive filler into the internal mixer for mixing. The discharge temperature of the mixed rubber is 120 - 125°C, and let it stand until room temperature; S33. Continue to add 1.5 - 2.5 parts of vulcanizing agent, 2 - 4 parts of vulcanization accelerator, and 15 - 18 parts of chitosan microspheres coated with piezoelectric ceramics into the internal mixer for mixing. The discharge temperature is 100 - 115°C. After letting it stand until room temperature, cut and send out the mixed rubber compound.

[0013] Preferably, the vulcanization activator is zinc oxide and stearic acid with a mass ratio of 2.5:1, the scorch retarder is scorch retarder CTP, the conductive filler is graphene and carbon nanotubes with a mass ratio of 2:1, the vulcanizing agent is sulfur powder, and the vulcanization accelerator is accelerator DM.

[0014] Further, step S4 is carried out in a vulcanizer. Based on the unit area of the grafting layer of the polyethylene board, put 6 - 10 kg / m 2 of the mixed rubber compound in the mold of the vulcanizer; the vulcanization temperature is 100 - 145°C, the pressure is 10 - 18 MPa, and the vulcanization time is 15 - 20 min.

[0015] Compared with the prior art, the fastener cushion plate and its preparation method of the present invention have the following advantages:

[0016] For the fastener cushion plate and its preparation method of the present invention, by setting a grafting layer on one side of the polyethylene board facing the rubber layer, the polyethylene board can not only be vulcanized and connected to the rubber layer through the grafting layer, but also generate van der Waals forces with the chitosan microspheres on the surface layer of the rubber layer, which can effectively improve the bonding strength between the polyethylene board and the rubber layer.

[0017] In addition, with the use of the fastener cushion plate, bacteria often gradually grow between the rubber layer, especially between the rubber layer and the polyethylene board, which will corrode and decompose the rubber material, especially damage the molecular connection bonds between the rubber layer and the polyethylene board, resulting in a poor connection strength between the polyethylene board and the rubber layer. Therefore, in this application, by adding chitosan microspheres to the rubber layer, in addition to improving the connection strength between the polyethylene board and the rubber layer, chitosan also plays an antibacterial and bactericidal role inside the rubber layer and between the rubber layer and the polyethylene board. On the one hand, it inhibits the corrosion and decomposition of the rubber layer by bacteria, which is beneficial to delaying the aging of the rubber. On the other hand, it is beneficial to maintaining a good bonding strength between the polyethylene board and the rubber layer for a long time. Description of the Drawings

[0018] The accompanying drawings, which form a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 It is a structural schematic diagram of a fastener pad in application according to an embodiment of the present invention (the rail structure above the pad is omitted).

[0020] Explanation of reference numerals:

[0021] 1. Polyethylene plate; 2. Rubber layer; 3. Chitosan microspheres; 4. Conductive member; 5. Processing module; 6. Wire. Detailed description of the specific implementation

[0022] Hereinafter, the inventive concepts of the present disclosure will be described using the terms that those skilled in the art would typically use to convey the substance of their work to other skilled artisans in the art. However, these inventive concepts may be embodied in many different forms and should not be construed as limited to the embodiments described herein.

[0023] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0024] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0025] In the prior art, a fastener pad with a small resistance is often used as the under-rail pad to reduce the friction coefficient with the rail, thereby reducing the sliding friction force between the two. At the same time, in order to overcome the corrosion problem existing in the stainless steel-rubber composite pad, a non-metal plate-elastic layer composite pad is often used in the prior art, which has obvious advantages in anti-corrosion and also has good performance in reducing the sliding friction force. However, the composite processing technology in the prior art is often relatively simple and it is difficult to ensure the connection strength between the non-metal plate and the elastic layer.

[0026] In order to solve the problem that the non-metal plate and the elastic layer are prone to separation in the prior art, as shown in the attached Figure 1 figure, this embodiment provides a fastener pad, which includes a polyethylene plate 1 and a rubber layer 2. The polyethylene plate 1 is connected to the rubber layer 2. A grafting layer (extremely thin in thickness and not shown) is provided on the side of the polyethylene plate 1 facing the rubber layer 2. The rubber layer 2 includes chitosan microspheres 3. The chitosan microspheres 3 are uniformly dispersed in the rubber layer 2. The grafting layer is respectively connected to the rubber layer 2 and the chitosan microspheres 3 on the surface layer of the rubber layer 2.

[0027] Therefore, in the present application, by providing a grafting layer on the side of the polyethylene plate 1 facing the rubber layer 2, the polyethylene plate 1 can not only be vulcanized and connected to the rubber layer 2 through the grafting layer, but also generate van der Waals forces with the chitosan microspheres 3 on the surface layer of the rubber layer 2, effectively improving the bonding strength between the polyethylene plate 1 and the rubber layer 2.

[0028] In addition, with the use of the fastener pad, bacteria often gradually grow between the rubber layer 2, especially between the rubber layer 2 and the polyethylene plate 1, which will corrode and decompose the rubber material, especially damage the molecular connection bonds between the rubber layer 2 and the polyethylene plate 1, resulting in a deterioration of the connection strength between the polyethylene plate 1 and the rubber layer 2. For this reason, in the present application, by adding chitosan microspheres 3 to the rubber layer 2, in addition to improving the connection strength between the polyethylene plate 1 and the rubber layer 2, the chitosan also plays an antibacterial and bactericidal role inside the rubber layer 2 and between the rubber layer 2 and the polyethylene plate 1. On the one hand, it inhibits the corrosion and decomposition of the rubber layer 2 by bacteria, which is beneficial to delaying the aging of the rubber. On the other hand, it is beneficial to maintaining good bonding strength between the polyethylene plate 1 and the rubber layer 2 for a long time.

[0029] In the present application, the polyethylene plate 1 is a commercially available ultra-high molecular weight polyethylene plate 1, which is a flat plate. The size requirements of the track pad can be met by customizing specific plate sizes, which will not be elaborated here. The material is preferably ultra-high molecular weight polyethylene with a molecular weight of more than 5 million. On the one hand, it ensures that the polyethylene plate 1 has good mechanical strength and meets the stiffness requirements of the track pad. On the other hand, it is beneficial to ensure that the polyethylene plate 1 has a good sliding friction coefficient and reduces the sliding friction force between the rail and the sub-rail pad.

[0030] Considering that various problems such as aging, wear, and tearing separation between the non-metallic plate and the elastic layer may occur during the long-term service of the fastener pad, it is necessary to timely obtain the service state of the fastener pad, so as to timely identify and replace the fastener pads with corresponding problems after long-term service, ensuring the long-term stability and safety of the rail transit system operation.

[0031] The rubber layer 2 further includes conductive fillers, which are also evenly dispersed in the rubber layer 2. The chitosan microspheres 3 are chitosan microspheres coated with piezoelectric ceramics, and the piezoelectric ceramics are preferably PTZ (lead zirconate titanate) piezoelectric ceramics.

[0032] The fastener backing plate includes a conductive member 4, which is disposed within the rubber layer 2 or on the side of the rubber layer 2 away from the polyethylene plate 1. The conductive member 4 is connected to the processing module 5 through a wire 6. The conductive member 4 can be a conventional conductive component such as a copper sheet or copper foil. When a train passes through a corresponding track section, a relatively high pressure will be applied to the track and the corresponding fastener backing plate within a short period of time. Correspondingly, there will also be a relatively high internal pressure within the rubber layer 2 under the action of elastic deformation. Thus, when a single train passes through a corresponding track section, a short-time micro-current pulse is generated by the piezoelectric ceramic under the piezoelectric effect. Since the side where the polyethylene plate 1 is located belongs to an insulating layer with good insulation performance, part of the micro-current is consumed within the rubber layer, and the other part of the micro-current will flow from the conductive member 4 to the processing module 5. The processing module 5 is at least capable of obtaining the current value of the micro-current pulse in real time when a train passes through a corresponding track section. It should be noted that during the entire process of a single train passing through a corresponding track section, the piezoelectric ceramic will form a micro-current pulse, rather than a continuous current output.

[0033] Preferably, the processing module 5 includes a current detector and a data processor. The current detector is a conventional high-precision current detector purchased on the market and is connected to the conductive member 4. It is used to detect the current value of the micro-current pulse in real time at least when a train passes through a corresponding track section. The data processor is connected to the current detector and is used to analyze and process the current value of the micro-current pulse. The data processor has an alarm for alarming when the current value of the micro-current pulse is abnormal.

[0034] Certainly, the current detector and the conductive member 4 can also be made into one body and disposed within the rubber layer 2 or on the side of the rubber layer 2 away from the polyethylene plate 1 at the same time. At this time, the processing module 5 includes a data processor. The current detector can be connected to the data processor through conventional wired data transmission or wireless data transmission to send the detected current value of the micro-current pulse to the data processor. In view of the data transmission technology, existing technologies can be directly adopted and will not be elaborated here. At the same time, for the remaining structures of the fastener backing plate, such as the shoulder, card slot and other structures, the conventional forms of fastener backing plates in the prior art can be referred to and will not be elaborated.

[0035] On this basis, the present application proposes a monitoring method for a fastener backing plate, including:

[0036] B1. During the process of a train passing through a track section, the current detector detects the current value of the micro-current pulse generated by the fastener backing plate in real time;

[0037] Among them, in the prior art, the identification technology for whether a train passes through a certain track section has been relatively conventional, such as through image comparison, vibration identification, etc. Therefore, this application can also directly adopt the prior art to automatically identify whether a train passes through the current track section through a data processor, so as to focus on monitoring the pulse current during the process of the train passing through the track section, which is beneficial to improving the automation and intelligence of the monitoring of the fastener pads. At the same time, the monitoring of the fastener pads in this application can be understood as the monitoring of the service state of the fastener pads.

[0038] B2. The data processor obtains the initial maximum current preset value A0 and the current value situation of the micro-current pulse when a single train passes through the track section.

[0039] Among them, A0 is the average value or weighted average of the maximum current that the fastener pad can reach in the initial stage of service (referring to the total number of train passes of 50 - 200 times) determined through laboratory simulation and evaluation tests before the fastener pad leaves the factory. Given that there may be differences in the formulations and components of fastener pads from different manufacturers or batches, as well as different requirements for the corresponding track application levels and different laboratory test and evaluation accuracies, all of which will result in different values of A0. In this application, A0 can be about 15 - 20 μA, but this application is not limited to this value and is only presented as an example.

[0040] For the current value situation, it is preferably a micro-current pulse curve with the time length as the x-axis and the current value as the y-axis during the time period when a single train passes through the track section, which includes the change of the current value with time and the maximum current value (i.e., the current pulse peak) in the micro-current pulse. Among them, when the data processor processes the current value situation, it can be considered that after a single train has just passed through the track section, it analyzes and processes the micro-current pulse curve formed during the time period when a single train passes through the track section.

[0041] B3. The data processor determines whether the ratio of the maximum current value A1 to A0 when a single train passes through the track section is less than the first-level warning coefficient a; if so, it proceeds to step B4; if not, it returns to step B1.

[0042] Among them, a is preferably 55% - 70%. If A1:A0 < a, it indicates that the current service state of the fastener pad may be difficult to meet the requirements of the track application level. If otherwise, it indicates that the current service state of the fastener pad is still good and can continue to serve in the current track system.

[0043] B4. The data processor determines whether the ratio of A1 to A0 is greater than the second-level warning coefficient b; if so, the data processor issues a maintenance reminder; if not, the data processor issues a maintenance and replacement alarm.

[0044] Among them, b is preferably 16%-22%. If a > A1: A0 > b, it indicates that the rubber layer 2 in the fastener cushion plate may have aged and hardened. As the train passes by, the internal elastic deformation ability of the rubber layer 2 becomes poor, resulting in a decrease in the pressure borne by the piezoelectric ceramic. At the same time, the aging and hardening of the rubber layer 2 in the track system will not only reduce the vibration damping effect, but also there is a risk of rupture of the internal microstructure of the rubber layer 2, affecting the safe operation of the track. The data processor needs to issue a maintenance reminder to remind the track maintenance personnel to check the corresponding fastener cushion plate and track fasteners in time to ensure the service state of the fastener cushion plate.

[0045] If A1: A0 ≤ b, it may be that the rubber layer 2 is severely aged, but the greater risk is the long-term wear between the rail and the polyethylene board 1. In the case of A1: A0 ≤ b, it may also be that the rail wears through the polyethylene board 1, resulting in the direct contact between the rail and the rubber layer 2. Since the rail is conductive, a part of the microcurrent generated in the rubber layer 2 will flow towards the rail, causing the microcurrent detected by the current detector to become smaller. In the long-term service state of the fastener cushion plate, whether the rubber layer 2 is severely aged or the rail wears through the polyethylene board 1, it means that the service life of the fastener cushion plate is basically up. The data processor needs to issue a maintenance alarm to remind the track maintenance personnel to repair and replace the corresponding fastener cushion plate and track fasteners in time to ensure the normal operation of the track system.

[0046] In addition, step B3 includes:

[0047] B31. The data processor determines whether there are at least two pulse peaks in the microcurrent pulse during the passage of a single train through the track section; if so, go to step B32; if not, go to step B33;

[0048] B32. The data processor issues a warning of delamination of the fastener cushion plate;

[0049] Among them, the fastener backing plate is a relatively integrated structure. When a train passes by, there will be a relatively stable force in the rubber layer 2, enabling the micro-current pulse generated by the piezoelectric ceramic to decay smoothly after reaching the pulse peak. However, if two or more pulse peaks are generated in the micro-current pulse during a single train passing through the track section, it indicates that under the impact force generated by the train passing at high speed, tearing separation may occur between the polyethylene plate 1 and the rubber layer 2 at a certain moment, or delamination may occur inside the rubber layer 2, resulting in fluctuations in the force in the rubber layer 2. As a result, the piezoelectric ceramic will be subjected to compressive force or elastic recovery (tensile) force, causing the micro-current pulse to also fluctuate correspondingly, thus forming two or more pulse peaks. Therefore, it is necessary for the data processor to issue a warning of delamination of the fastener backing plate to remind the track maintenance personnel to promptly check the current structural state of the corresponding fastener backing plate. If it is confirmed that the fastener backing plate has undergone structural delamination, the corresponding fastener backing plate can be replaced as soon as possible to ensure the normal operation of the track system.

[0050] B33. The data processor determines whether the ratio of the maximum current value A1 to A0 of the current when a single train passes through the track section is less than the first-level warning coefficient a; if so, proceed to step B4; if not, return to step B1;

[0051] On the basis that there is no risk of delamination of the fastener backing plate, the original content of steps B3 and B4 can be continued to be executed, which is the same as above and will not be elaborated here.

[0052] In addition, when a single train passes through the track section, if no micro-current pulse is detected in steps B1 - B2, or in other words, the current value of the micro-current pulse is zero when a single train passes through the track section, or the current value of the micro-current pulse decays to zero instantaneously, it may indicate that the conductive part 4 (or current detector) is separated from the rubber layer 2, or the detection element is damaged. The data processor issues a zero-signal warning to remind the track maintenance personnel to promptly check the assembly condition and operating state of the corresponding detection element of the fastener backing plate to ensure the normal progress of the monitoring process of the fastener backing plate.

[0053] In this application, chitosan is used to coat the piezoelectric ceramic. On the one hand, it can optimize the dispersion performance of the piezoelectric ceramic in the rubber system, improve the dispersion uniformity of the piezoelectric ceramic in the rubber layer 2, prevent the aggregation of the piezoelectric ceramic, enable the piezoelectric effect with similar strength to be realized in different regions of the rubber layer 2, and avoid the over-concentration of the micro-current. On the other hand, the amino groups in the chitosan molecular chain can effectively crosslink with the rubber, which is beneficial to improving the macroscopic mechanical properties of the rubber layer 2. Microscopically, it also enables the piezoelectric ceramic to be more firmly distributed in the rubber system, avoiding incompatibility between different interfaces, ensuring that the piezoelectric ceramic can play a long-term effective piezoelectric role in the fastener backing plate, and is conducive to realizing the long-term effectiveness of the monitoring process of the fastener backing plate.

[0054] In addition, by using the piezoelectric effect to monitor the service state of the fastener pad in this application, the fastener pad can be directly, simply and conveniently applied to the track system in the prior art, and the existing track system can also timely detect problems such as component aging, wear, and delamination that may exist in the fastener pad during long-term service. This is beneficial for timely inspection and replacement of the fastener pads with corresponding problems, can improve the intelligent monitoring level of the operation of the existing track system, and is conducive to ensuring the long-term safe and stable operation of the track system.

[0055] For the preparation method of the fastener pad, it includes:

[0056] S1. Perform two-stage surface treatment on the polyethylene board 1, and after drying, form a grafted layer on the polyethylene board 1;

[0057] S2. Prepare the chitosan microspheres 3;

[0058] S3. Knead the rubber material and the chitosan microspheres 3 in a mixer to obtain a mixed rubber material;

[0059] S4. Place the mixed rubber material on the grafted layer, and vulcanize the grafted layer of the polyethylene board 1 and the mixed rubber material integrally to produce the fastener pad.

[0060] In step S1, the two-stage surface treatment includes a mechanical surface treatment process and a surface grafting treatment process carried out in sequence. Specifically, the mechanical surface treatment process is to use a conventional grinding machine to grind the surface to be treated of the polyethylene board 1 so that the surface roughness of the surface to be treated reaches more than 45 μm, and blow the surface to be treated of the polyethylene board 1 clean with compressed air to form a rough surface of the polyethylene board 1. For the grinding machine and related grinding operations, they are all prior art and will not be elaborated here.

[0061] The surface grafting treatment process is as follows: Under the irradiation of ultraviolet light with a wavelength of 290 nm, immerse the rough surface of the polyethylene board 1 into the benzophenone-acrylic acid solution. After soaking for 15 minutes, take out the polyethylene board 1, and then use acetone to clean and dry the rough surface of the polyethylene board 1 to obtain the polyethylene board 1 with a grafted layer. Among them, the benzophenone-acrylic acid solution is a solution formed by dissolving benzophenone in acrylic acid to form a benzophenone-acrylic acid solution with a mass percentage of benzophenone of 1.3%.

[0062] For the preparation process of the chitosan microspheres coated with piezoelectric ceramics, that is, step S2 includes:

[0063] S21. Add nanoscale piezoelectric ceramics into ethanol, stir evenly and then disperse them by ultrasonic waves. After that, add diethanolamine and stir evenly to obtain a piezoelectric ceramic suspension. After filtration, dry and grind the precipitate to obtain modified piezoelectric ceramics;

[0064] Among them, the nanoscale piezoelectric ceramics are commercially available nanoscale piezoelectric ceramics, and their material is preferably PTZ (lead zirconate titanate) piezoelectric ceramics. The surface of the nanoscale piezoelectric ceramics is subjected to the first-level surface treatment with diethanolamine.

[0065] S22. Add the modified piezoelectric ceramics into ethanol, stir evenly and then disperse them ultrasonically to obtain a modified piezoelectric ceramics suspension with a concentration of 0.01 g / mL.

[0066] S23. Add chitosan into an aqueous acetic acid solution with a mass fraction of 1%, stir evenly to obtain a chitosan solution with a concentration of 0.016 g / mL.

[0067] S24. Stir and mix the modified piezoelectric ceramics suspension prepared in step S22 and the chitosan solution prepared in step S23 evenly according to a volume ratio of 1:1 to obtain a mixed solution A.

[0068] Among them, through step S21, the surface of the nanoscale piezoelectric ceramics is subjected to the first-level surface treatment with diethanolamine, so that the modified piezoelectric ceramics can be evenly dispersed in the chitosan solution, which is convenient for the chitosan to carry out the second-level surface treatment on the piezoelectric ceramics and the subsequent coating of the piezoelectric ceramics by chitosan.

[0069] S25. Add propylene glycol fatty acid ester into liquid paraffin, stir and mix evenly to obtain a mixed solution B.

[0070] Among them, the mass ratio of liquid paraffin to propylene glycol fatty acid ester is 42:1.

[0071] S26. Under a constant temperature water bath at 50 °C, add the mixed solution A dropwise into the mixed solution B, stir evenly to obtain a mixed solution C.

[0072] S27. After rapidly cooling the mixed solution C in an ice-water bath, take it out and then heat the mixed solution C to 30 °C, add glutaraldehyde with a volume fraction of 1.8%, and stir constantly for 5 h to obtain a chitosan microsphere emulsion coating the piezoelectric ceramics.

[0073] S28. After centrifuging, filtering, washing, and drying the emulsion prepared in step S27, chitosan microspheres coating the piezoelectric ceramics are obtained.

[0074] Therefore, through the two-level surface treatment of the piezoelectric ceramics, on the one hand, it is beneficial for chitosan to uniformly coat the piezoelectric ceramics to form chitosan microspheres with relatively similar particle sizes; on the other hand, the piezoelectric ceramics can achieve good compatibility in the rubber system through the amine-based functional groups after surface modification, avoiding interfacial peeling of the piezoelectric ceramics in the rubber, ensuring that the piezoelectric ceramics can play a long-term effective piezoelectric effect in the fastener pad, and being conducive to realizing the long-term effectiveness of the monitoring process of the fastener pad.

[0075] For the treatment of the rubber compound, in step S3, it includes:

[0076] S31. By weight, put 100 parts of natural rubber compound into a kneader for plasticizing. The plasticizing temperature is 90 - 110 °C, the rotation speed is 30 - 40 revolutions per minute, and plasticize for 3 - 4 minutes;

[0077] S32. Add 5 - 8 parts of vulcanization activator, 0.5 - 1.6 parts of scorch retarder, and 8 - 13 parts of conductive filler to the kneader for mixing. The discharge temperature of the mixed rubber is 120 - 125 °C, and let it stand until room temperature;

[0078] S33. Continue to add 1.5 - 2.5 parts of vulcanizing agent, 2 - 4 parts of vulcanization accelerator, and 15 - 18 parts of chitosan microspheres coated with piezoelectric ceramics to the kneader for mixing. The discharge temperature is 100 - 115 °C. After letting it stand until room temperature, cut and send out the mixed rubber compound.

[0079] In step S3, the vulcanization activator is zinc oxide and stearic acid with a mass ratio of 2.5:1, the scorch retarder is commercially available scorch retarder CTP, the conductive filler is graphene and carbon nanotubes with a mass ratio of 2:1, the vulcanizing agent is sulfur powder, and the vulcanization accelerator is commercially available accelerator DM. For the related operations of rubber plasticizing and mixing, they are all prior arts and will not be elaborated.

[0080] Step S4 is carried out in a vulcanizer. Based on the unit area of the grafting layer of polyethylene board 1, put 6 - 10 kg / m 2 of the mixed rubber compound in the mold of the vulcanizer; among them, for every 1 m 2 of the grafting layer of polyethylene board 1, place 6 - 10 kg / m 2 of the mixed rubber compound. The corresponding area is the area of the board in the common understanding, which is the product of the length and width of the board. During the vulcanization process of step S4, the vulcanization temperature is 100 °C - 145 °C, the pressure is 10 MPa - 18 MPa, and the vulcanization time is 15 min - 20 min.

[0081] In the actual vulcanization operation, it is necessary to place the grafting layer of polyethylene board 1 upward and put polyethylene board 1 into the mold of the vulcanizer, and then fill the mixed rubber compound above the grafting layer. For the vulcanization equipment and vulcanization operation, the prior arts can be directly adopted and will not be elaborated.

[0082] The following further describes the specific embodiments of the present invention in combination with the embodiments, and the present invention is not limited to the described embodiments.

[0083] Embodiment 1

[0084] Treatment of polyethylene board 1

[0085] The surface to be treated of the polyethylene plate 1 (ultra-high molecular weight polyethylene plate with a molecular weight greater than 5 million, the same below) is polished so that the surface roughness of the surface to be treated reaches more than 45 μm, and the surface to be treated of the polyethylene plate 1 is blown clean with compressed air to form a rough surface of the polyethylene plate 1.

[0086] Under the irradiation of ultraviolet light with a wavelength of 290 nm, the rough surface of the polyethylene plate 1 is immersed in a benzophenone-acrylic acid solution. After soaking for 15 minutes, the polyethylene plate 1 is taken out, and then the rough surface of the polyethylene plate 1 is cleaned and dried with acetone to obtain the polyethylene plate 1 with a grafted layer. The benzophenone-acrylic acid solution is a benzophenone-acrylic acid solution with a mass percentage of benzophenone of 1.3%.

[0087] Preparation of chitosan microspheres 3

[0088] The nano-scale PTZ piezoelectric ceramics are added to ethanol, stirred evenly and then ultrasonically dispersed. After that, diethanolamine is added, and after stirring evenly, a piezoelectric ceramic suspension is obtained. After filtration, the precipitate is dried and ground to obtain modified piezoelectric ceramics;

[0089] The modified piezoelectric ceramics are added to ethanol, stirred evenly and then ultrasonically dispersed to obtain a modified piezoelectric ceramic suspension with a concentration of 0.01 g / mL;

[0090] Chitosan is added to an aqueous acetic acid solution with a mass fraction of 1%, and after stirring evenly, a chitosan solution with a concentration of 0.016 g / mL is obtained;

[0091] The modified piezoelectric ceramic suspension and the chitosan solution are stirred and mixed evenly at a volume ratio of 1:1 to obtain a mixed solution A;

[0092] Propylene glycol fatty acid ester is added to liquid paraffin, and after stirring and mixing evenly, a mixed solution B is obtained, and the mass ratio of liquid paraffin to propylene glycol fatty acid ester is 42:1;

[0093] Under a constant temperature water bath at 50 °C, the mixed solution A is added dropwise to the mixed solution B, and after stirring evenly, a mixed solution C is obtained;

[0094] After the mixed solution C is quenched by an ice-water bath, it is taken out and then the temperature of the mixed solution C is raised to 30 °C, and glutaraldehyde with a volume fraction of 1.8% is added, and it is stirred at a constant temperature for 5 h to obtain an emulsion of chitosan microspheres coated with piezoelectric ceramics; after centrifugation, filtration, washing and drying of the emulsion, chitosan microspheres coated with piezoelectric ceramics are obtained.

[0095] Preparation of mixed rubber

[0096] By weight, 100 parts of natural rubber compound are put into a mixer for plasticizing, the plasticizing temperature is 90 °C, the rotation speed is 40 revolutions per minute, and the plasticizing time is 3 minutes;

[0097] Add 6 parts of vulcanization activator, 0.5 part of scorch retarder, and 10 parts of conductive filler into the internal mixer for mixing. The discharge temperature of the mixed rubber is 125 °C, and it is parked until it reaches room temperature.

[0098] Continue to add 1.9 parts of vulcanizing agent, 2 parts of vulcanization accelerator, and 18 parts of chitosan microspheres coated with piezoelectric ceramics into the internal mixer for mixing. The discharge temperature is 107 °C. After parking until it reaches room temperature, cut and send out the mixed rubber compound.

[0099] Among them, the vulcanization activator is zinc oxide and stearic acid with a mass ratio of 2.5:1, the scorch retarder is commercially available scorch retarder CTP, the conductive filler is graphene and carbon nanotubes with a mass ratio of 2:1, the vulcanizing agent is sulfur powder, and the vulcanization accelerator is commercially available accelerator DM.

[0100] Vulcanization

[0101] In the vulcanizer mold, place the grafting layer of the polyethylene plate 1 upwards, and take part of the mixed rubber compound and place it above the grafting layer. The filling ratio is: based on the unit area of the grafting layer of the polyethylene plate 1, fill 7 kg / m 2 of the mixed rubber compound in the vulcanizer mold. The vulcanization parameters during the vulcanization process are: vulcanization temperature is 145 °C, pressure is 10 MPa, and vulcanization time is 15 min.

[0102] After vulcanization, the fastener cushion plate is prepared, and the bonding strength of the fastener cushion plate is detected. The results are shown in Table 1.

[0103] Example 2

[0104] This example is the same as Example 1 in "Treatment of Polyethylene Plate 1" and "Preparation of Chitosan Microspheres 3", and will not be elaborated.

[0105] Preparation of mixed rubber compound

[0106] By weight, put 100 parts of natural rubber compound into the internal mixer for plasticizing. The plasticizing temperature is 110 °C, the rotation speed is 33 revolutions per minute, and the plasticizing time is 4 minutes.

[0107] Add 5 parts of vulcanization activator, 1.2 parts of scorch retarder, and 13 parts of conductive filler into the internal mixer for mixing. The discharge temperature of the mixed rubber is 120 °C, and it is parked until it reaches room temperature.

[0108] Continue to add 1.5 parts of vulcanizing agent, 4 parts of vulcanization accelerator, and 15 parts of chitosan microspheres coated with piezoelectric ceramics into the internal mixer for mixing. The discharge temperature is 100 °C. After parking until it reaches room temperature, cut and send out the mixed rubber compound.

[0109] Among them, the vulcanization activator is zinc oxide and stearic acid with a mass ratio of 2.5:1, the scorch retarder is the commercially available scorch retarder CTP, the conductive filler is graphene and carbon nanotubes with a mass ratio of 2:1, the vulcanizing agent is sulfur powder, and the vulcanization accelerator is the commercially available accelerator DM.

[0110] Vulcanization

[0111] In the vulcanizing machine mold, the grafting layer of the polyethylene plate 1 is facing upward, and a part of the mixed rubber compound is placed above the grafting layer. The filling ratio is: based on the unit area of the grafting layer of the polyethylene plate 1, 6 kg / m of the mixed rubber compound is filled in the mold of the vulcanizing machine. 2 The vulcanization parameters during vulcanization are: the vulcanization temperature is 100 °C, the pressure is 18 MPa, and the vulcanization time is 19 min.

[0112] After vulcanization, the fastener backing plate is obtained, and the bonding strength of the fastener backing plate is detected. The results are shown in Table 1.

[0113] Example 3

[0114] This example is the same as Example 1 in "Treatment of Polyethylene Plate 1" and "Preparation of Chitosan Microspheres 3", and will not be elaborated.

[0115] Preparation of Mixed Rubber Compound

[0116] By weight, 100 parts of natural rubber compound are put into a kneader for plasticization. The plasticization temperature is 98 °C, the rotation speed is 30 revolutions per minute, and the plasticization time is 3 minutes;

[0117] 8 parts of vulcanization activator, 1.6 parts of scorch retarder, and 8 parts of conductive filler are added to the kneader for mixing. The discharge temperature of the mixed rubber is 122 °C, and it is left to stand until room temperature;

[0118] Continue to add 2.5 parts of vulcanizing agent, 2.7 parts of vulcanization accelerator, and 17 parts of chitosan microspheres coated with piezoelectric ceramics to the kneader for mixing. The discharge temperature is 115 °C. After leaving it to stand until room temperature, the mixed rubber compound is cut and sent out;

[0119] Among them, the vulcanization activator is zinc oxide and stearic acid with a mass ratio of 2.5:1, the scorch retarder is the commercially available scorch retarder CTP, the conductive filler is graphene and carbon nanotubes with a mass ratio of 2:1, the vulcanizing agent is sulfur powder, and the vulcanization accelerator is the commercially available accelerator DM.

[0120] Vulcanization

[0121] In the vulcanizing machine mold, the grafting layer of the polyethylene plate 1 is facing upward, and a part of the mixed rubber compound is placed above the grafting layer. The filling ratio is: based on the unit area of the grafting layer of the polyethylene plate 1, 10 kg / m of the mixed rubber compound is filled in the mold of the vulcanizing machine. 2The mixed rubber compound. The vulcanization parameters during vulcanization are: vulcanization temperature is 128 °C, pressure is 13 MPa, and vulcanization time is 20 min.

[0122] After vulcanization, the fastener backing plate is obtained, and the adhesive strength of the fastener backing plate is detected, and the results are shown in Table 1.

[0123] Example 4

[0124] This example is the same as Example 1 in "treatment of polyethylene plate 1" and "preparation of chitosan microspheres 3", which will not be elaborated.

[0125] Preparation of mixed rubber compound

[0126] By weight, 100 parts of natural rubber compound are put into a mixer for plasticizing. The plasticizing temperature is 107 °C, the rotation speed is 36 revolutions per minute, and the plasticizing time is 4 minutes;

[0127] 7 parts of vulcanization activator, 1 part of scorch retarder, and 9 parts of conductive filler are added to the mixer for mixing. The discharge temperature of the mixed rubber is 124 °C, and it is parked until room temperature;

[0128] 2.2 parts of vulcanizing agent, 3.2 parts of vulcanization accelerator, and 17 parts of chitosan microspheres coated with piezoelectric ceramics are continuously added to the mixer for mixing. The discharge temperature is 110 °C. After parking until room temperature, the mixed rubber compound is cut and sent out;

[0129] Among them, the vulcanization activator is zinc oxide and stearic acid with a mass ratio of 2.5:1, the scorch retarder is commercially available scorch retarder CTP, the conductive filler is graphene and carbon nanotubes with a mass ratio of 2:1, the vulcanizing agent is sulfur powder, and the vulcanization accelerator is commercially available accelerator DM.

[0130] Vulcanization

[0131] In the vulcanizer mold, the grafted layer of polyethylene plate 1 is facing up, and a part of the mixed rubber compound is filled above the grafted layer. The filling ratio is: based on the unit area of the grafted layer of polyethylene plate 1, 8 kg / m is filled in the mold of the vulcanizer 2 of the mixed rubber compound. The vulcanization parameters during vulcanization are: vulcanization temperature is 134 °C, pressure is 15 MPa, and vulcanization time is 17 min.

[0132] After vulcanization, the fastener backing plate is obtained, and the adhesive strength of the fastener backing plate is detected, and the results are shown in Table 1.

[0133] Comparative Example 1

[0134] This comparative example is based on Example 4, and the difference is that this comparative example does not carry out the "preparation of chitosan microspheres 3", and correspondingly, the chitosan microspheres coated with piezoelectric ceramics are not added during the "preparation of mixed rubber compound" process.

[0135] The remaining operating conditions and process sequence are the same as those in Example 4, and the fastener backing plate is prepared. The bonding strength of the fastener backing plate is detected, and the results are shown in Table 1.

[0136] Comparative Example 2

[0137] This comparative example is based on Example 4. The difference is that the second step of the "treatment of polyethylene sheet 1" (i.e., the surface grafting treatment process) is not carried out in this comparative example, so that the polyethylene sheet 1 is only ground into a rough surface without a grafted layer. During vulcanization, the rough surface of the polyethylene sheet 1 faces upward.

[0138] The remaining operating conditions and process sequence are the same as those in Example 4, and the fastener backing plate is prepared. The bonding strength of the fastener backing plate is detected, and the results are shown in Table 1.

[0139] Comparative Example 3

[0140] Taking Example 3 of the prior art CN113863065A as a comparative example, the specific content is as follows:

[0141] S1. The bonding surface of the polyethylene sheet 1 (polytetrafluoroethylene sheet with a molecular weight greater than 5 million, the same below) is sandblasted, and then the bonding surface of the polyethylene sheet 1 is blown clean with compressed air to form a rough surface of the polyethylene sheet 1; then the rough surface of the polyethylene sheet 1 is immersed in a naphthalene sodium solution for activation treatment. After soaking for 25 minutes, the polyethylene sheet 1 is taken out, and then the rough surface of the polyethylene sheet 1 is ultrasonically cleaned in water. Subsequently, the polyethylene sheet 1 is taken out. After the rough surface of the polyethylene sheet 1 is dried, it is the active bonding surface. Then, according to GB / T 30693-2014, the contact angle A between the active bonding surface and water is measured to be 7°.

[0142] S2. The active bonding surface is coated with TipTop SC2000 adhesive, and then the polyethylene sheet 1 is placed into the vulcanizer mold in the preheating process with the active bonding surface facing upward. The preheating process of the vulcanizer adopts the above steps S23-S25 until the adhesive is dried, and then step S3 is carried out; among them, the heating rate in step S23 is 2°C, and the preset temperature in step S24 is 110°C.

[0143] S3. In the preheated vulcanizer mold, 8 kg of natural rubber particles are filled on the active bonding surface of the polyethylene sheet 1 per 1 m 2 of the polyethylene sheet 1, and the polyethylene sheet 1, TipTop SC2000 adhesive, and rubber compound are vulcanized integrally to obtain a finished product of a small resistance backing plate. The vulcanization parameters are: vulcanization temperature 170°C, pressure 20 MPa, and vulcanization time 20 minutes.

[0144] The bonding strength of the prepared backing plate is detected, and the results are shown in Table 1.

[0145] Comparative Example 4

[0146] Applied to track fasteners, a commercially available conventional stainless steel-rubber backing plate was subjected to a bonding strength test, and the results are shown in Table 1.

[0147] Table 1 Bonding strength test of relevant backing plates in Examples 1-4 and Comparative Examples 1-3

[0148] Adhesion strength, kN / m Example 1 8.4 Example 2 8.2 Example 3 8.5 Example 4 8.8 Comparative Example 1 6.7 Comparative Example 2 3.9 Comparative Example 3 7.4 Comparative Example 4 4.2

[0149] Among them, the bonding strength test process was carried out in accordance with GB / T7760-2003 "Determination of the adhesion strength of vulcanized rubber or thermoplastic rubber to rigid plates - 90° peel method".

[0150] It can be seen from the data in Table 1 that among the fastener backing plates prepared in Examples 1-4 of the present application, the bonding strength between the non-metallic plate and the elastic layer is significantly higher than that of the commercially available conventional stainless steel-rubber backing plate (Comparative Example 4), and it has statistical significance (p < 0.01).

[0151] At the same time, comparing Examples 1-4 of the present application with the backing plate (Comparative Example 3) in the prior art in which the non-metallic plate and the elastic layer are bonded by an adhesive, it can be seen that: by providing a grafted layer on the polyethylene plate 1 and chitosan microspheres 3 on the rubber layer 2 in the present application, on the one hand, the grafted layer can generate vulcanization crosslinking with the rubber molecular chains during the rubber vulcanization process, and on the other hand, the microscopic grafted chains of the grafted layer have a large number of carbonyl and hydroxyl groups, and more reliable hydrogen bonds are formed between the hydroxyl groups of the chitosan molecular chain and the carbonyl and hydroxyl groups of the grafted layer, which can increase the connection force between the polyethylene plate 1 and the rubber layer 2 in the microscopic structure and improve the bonding strength of the fastener backing plate prepared in the present application.

[0152] At the same time, by comparing Examples 1-4 with Comparative Example 1, it can be seen that: if the chitosan microspheres 3 are not provided in the rubber layer 2, the bonding strength of the fastener backing plate will decrease to a certain extent, and its bonding strength is similar to that of the backing plate in the prior art in which the non-metallic plate and the elastic layer are bonded by an adhesive. Although it cannot play a piezoelectric role in the fastener backing plate and cannot monitor the service state of the fastener backing plate, it still has certain practical application value and can also be used as one of the implementation schemes of the present application and applied to the track system.

[0153] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation method of a fastener backing plate, characterized in that, the fastener backing plate includes a polyethylene plate (1) and a rubber layer (2). The polyethylene plate (1) is connected to the rubber layer (2). A grafting layer is provided on one side of the polyethylene plate (1) facing the rubber layer (2). The rubber layer (2) includes chitosan microspheres (3). The chitosan microspheres (3) are uniformly dispersed in the rubber layer (2). The grafting layer is respectively connected to the rubber layer (2) and the chitosan microspheres (3) on the surface layer of the rubber layer (2); the preparation method includes: S1. Perform two-stage surface treatment on the polyethylene plate (1) to form a grafting layer of the polyethylene plate (1); S2. Prepare chitosan microspheres (3); S3. Knead the rubber material and chitosan microspheres (3) in a mixer to obtain a mixed rubber material; S4. Place the mixed rubber material on the grafting layer, and vulcanize the grafting layer of the polyethylene plate (1) and the mixed rubber material integrally to obtain the fastener backing plate; the two-stage surface treatment includes a mechanical surface treatment process and a surface grafting treatment process carried out in sequence; in step S2, the chitosan microspheres (3) are chitosan microspheres coated with piezoelectric ceramics; step S2 includes: S21. Add nano-level piezoelectric ceramics to ethanol, stir evenly and then disperse ultrasonically. Then add diethanolamine, stir evenly to obtain a piezoelectric ceramic suspension. After filtration, dry and grind the precipitate to obtain modified piezoelectric ceramics; S22. Add the modified piezoelectric ceramics to ethanol, stir evenly and then disperse ultrasonically to obtain a modified piezoelectric ceramic suspension with a concentration of 0.01 g / mL; S23. Add chitosan to an acetic acid aqueous solution with a mass fraction of 1%, stir evenly to obtain a chitosan solution with a concentration of 0.016 g / mL; S24. Stir and mix the modified piezoelectric ceramic suspension prepared in step S22 and the chitosan solution prepared in step S23 evenly according to a volume ratio of 1:1 to obtain a mixed solution A; S25. Add propylene glycol fatty acid ester to liquid paraffin, stir and mix evenly to obtain a mixed solution B; S26. Dropwise add the mixed solution A to the mixed solution B under a constant temperature water bath at 50 °C, stir evenly to obtain a mixed solution C; S27. After quenching the mixed solution C in an ice-water bath, take it out and then heat the mixed solution C to 30 °C, add glutaraldehyde with a volume fraction of 1.8%, and stir constantly for 5 h to obtain an emulsion of chitosan microspheres coated with piezoelectric ceramics; S28. After centrifuging, filtering, washing and drying the emulsion prepared in step S27, obtain chitosan microspheres coated with piezoelectric ceramics.

2. The preparation method of a fastener backing plate according to claim 1, characterized in that, the rubber layer (2) includes conductive fillers, and the conductive fillers are uniformly dispersed in the rubber layer (2).

3. The preparation method of a fastener backing plate according to claim 1, characterized in that, the mechanical surface treatment process is to use a grinding machine to grind the surface to be treated of the polyethylene plate (1) so that the surface roughness of the surface to be treated reaches more than 45 μm, and blow the surface to be treated of the polyethylene plate (1) clean with compressed air to form a rough surface of the polyethylene plate (1); The surface grafting treatment process is as follows: Under the state of ultraviolet light irradiation, immerse the rough surface of the polyethylene plate (1) into the benzophenone-acrylic acid solution. After soaking for 15 minutes, take out the polyethylene plate (1), and then use acetone to clean and dry the rough surface of the polyethylene plate (1) to obtain the polyethylene plate (1) with a grafted layer.

4. A method for preparing a fastener cushion plate according to claim 1, characterized in that, Step S3 includes: S31. Put 100 parts of natural rubber compound into a mixer for plasticizing. The plasticizing temperature is 90-110°C, the rotation speed is 30-40 revolutions per minute, and plasticize for 3-4 minutes; S32. Add 5-8 parts of vulcanization activator, 0.5-1.6 parts of scorch retarder, and 8-13 parts of conductive filler to the mixer for mixing. The discharge temperature of the mixed rubber is 120-125°C, and let it stand until room temperature; S33. Continue to add 1.5-2.5 parts of vulcanizing agent, 2-4 parts of vulcanization accelerator, and 15-18 parts of chitosan microspheres coated with piezoelectric ceramics to the mixer for mixing. The discharge temperature is 100-115°C. After standing until room temperature, cut and send out the mixed rubber compound.

5. A method for preparing a fastener cushion plate according to claim 4, characterized in that, The vulcanization activator is zinc oxide and stearic acid with a mass ratio of 2.5:1, the scorch retarder is scorch retarder CTP, the conductive filler is graphene and carbon nanotubes with a mass ratio of 2:1, the vulcanizing agent is sulfur powder, and the vulcanization accelerator is accelerator DM.

6. A method for preparing a fastener cushion plate according to claim 1, characterized in that, Step S4 is carried out in a vulcanizer. Based on the unit area of the grafting layer of the polyethylene plate (1), 6 - 10 kg / m 2 of the mixed rubber compound is filled in the mold of the vulcanizer; the vulcanization temperature is 100 - 145 °C, the pressure is 10 - 18 MPa, and the vulcanization time is 15 - 20 min.

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