Insulated rubber sheathed cable repair strip and preparation method and application thereof

Abstract

The present invention relates to an insulating rubber sheath cable repair strip and a preparation method and application thereof. The insulating rubber sheath cable repair strip comprises a reinforcing tensile element and a re-vulcanizable rubber strip, wherein the reinforcing tensile element is arranged at the center of the re-vulcanizable rubber strip; the re-vulcanizable rubber strip comprises: 86-90 parts of chlorinated polyethylene, 10-14 parts of ethylene propylene rubber, 10-14 parts of magnesium oxide, 7-9 parts of flame retardant, 0.7-0.9 parts of antioxidant, 10-14 parts of carbon black, 13-17 parts of white carbon black, 18-22 parts of clay, 10-14 parts of talc, 13-17 parts of plasticizer, 10-14 parts of diisooctyl adipate, 0.7-0.9 parts of paraffin wax, 0.9-1.1 parts of polyethylene wax, 2.3-2.7 parts of vulcanizing agent, and 1.8-2.2 parts of vulcanizing agent. The present invention solves the problems of facilitating the repair of cable sheaths and facilitating production, more effectively saving costs and reducing safety.

Description

Technical Field

[0001] The invention relates to the technical field of cables, and in particular to an insulating rubber sheathed cable repair strip and a preparation method and application thereof. Background Art

[0002] Mining cables are mainly used as special cable products for ground and underground equipment in the mining industry. The use environment of mining cables is very complex, the working environment is very harsh, and gas and coal dust gather, which is easy to cause explosions, so the cable safety requirements are very high. This product needs to be moved, bent, twisted, etc. frequently during use, so the wires are required to be soft, stable in structure, not easy to kink, etc., and have certain wear resistance. At the same time, during the use of mining cables by users, the surface of the cable sheath is rubbed against the ground or other sharp objects for a long time, resulting in the sheath being damaged, causing the cable to fail to protect the cable, thereby affecting the service life and safety of the cable. Therefore, when the sheath of mining cables is damaged during use, most of them are replaced with new products.

[0003] In order to ensure the service life of the cable and avoid safety problems, the cable needs to be repaired when the cable sheath is damaged. The existing repair technologies are:

[0004] 1. Wrap a layer of rubber tape with a material similar to that of the sheath on the surface of the sheath, and finally perform compression molding on a compression molding machine. The compression molding temperature and time are 180-200℃ and 30min respectively.

[0005] 2. Use rubber to repair. The rubber used should be consistent with the wire material of the repaired wire, and the rubber content should be higher than the repaired material, and the vulcanization system should be slightly stronger. The repair method includes: 1. Set the temperature and time according to the vulcanization system of the rubber. 2. Use rubber ink thinner to wipe the repaired area, especially the joints should be fully treated. 3. Cut the repair rubber according to the size of the gap, and be careful not to be too much or too little. 4. Plug the cut rubber into the gap, and be careful not to let the rubber be higher than the circumference of the wire. 5. Wrap it with high-temperature resistant PP tape. And put it into a tubular mold cavity slightly smaller than the wire diameter, lock the upper and lower molds, and let the repaired position have a certain pressure. Note that the mold cavity diameter is slightly smaller than the wire diameter by 0.1~0.2mm. 6. When the vulcanization time is up, take out the product. If a small amount of rubber overflows, use a sharp blade to trim it and wipe it with thinner.

[0006] However, the above two methods cannot guarantee the roundness of the cable. If glue or rubber particles are used for repair and filling, the gap cannot be filled because there are gaps between the glue and the glue or between the rubber particles. During the die pressing, the gas in the middle cannot be effectively discharged, which affects the structural stability of the cable core. When the cable is bent, the core wire is prone to dislocation and deformation, and is prone to collision and bending, resulting in structural damage, and has the disadvantage of poor protection effect. Summary of the invention

[0007] The invention aims to provide an insulating rubber sheathed cable repair strip and a preparation method thereof, so as to prolong the service life of mining cables and reduce costs.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] An insulating rubber sheathed cable repair strip comprises a reinforcing tensile element and a re-vulcanizable rubber strip, wherein the reinforcing tensile element is arranged at the center of the re-vulcanizable rubber strip;

[0010] The re-vulcanizable rubber strip comprises: 86-90 parts of chlorinated polyethylene (CPE3000), 10-14 parts of ethylene propylene diene rubber (KEP210), 10-14 parts of magnesium oxide, 7-9 parts of flame retardant, 0.7-0.9 parts of antioxidant, 10-14 parts of carbon black N330, 13-17 parts of white carbon black, 18-22 parts of clay, 10-14 parts of talc, 13-17 parts of plasticizer TOTM, 10-14 parts of diisooctyl adipate (DOA), 0.7-0.9 parts of paraffin wax, 0.9-1.1 parts of polyethylene wax, 2.3-2.7 parts of vulcanizing agent, and 1.8-2.2 parts of vulcanizing agent.

[0011] The preparation method of the re-vulcanizable rubber strip comprises the following steps:

[0012] Step 1, adding chlorinated polyethylene and EPDM rubber into an internal mixer and plasticizing for 2-3 minutes;

[0013] Step 2, add other components except the vulcanizing agent and the co-vulcanizing agent, mix for 3-4 minutes, and discharge at 90-100°C;

[0014] Step 3, the discharged mixed rubber material is thinned once on the open mill and then turned over 2-3 times on the rubber turning machine, then calendered on the open mill, and cooled on the cooling roller to form a sheet;

[0015] Step 4: The semi-finished product is placed for 10-12 hours after being produced, and then put into an internal mixer for mixing, and a vulcanizing agent and a co-vulcanizing agent are added at a temperature of 80-90° C., mixed for 1 minute, and discharged to discharge the mixed rubber material;

[0016] Step 5, the mixed rubber material is thinned once on the open mill, then turned over 2-3 times on the rubber turning machine, and then calendered on the open mill, and then packed into boxes after passing through the cooling roller talcum powder box to obtain the film;

[0017] Step 6: Extruding the film at 70-90° C. to obtain an insulating rubber sheathed cable repair strip.

[0018] The insulating rubber sheathed cable repair strip of the present invention is safer, soft, and can be re-vulcanized after heating. Its performance satisfies the re-vulcanization performance after heating, effectively ensures the roundness of the cable and the stability of the core wire structure, solves the problem that the core wire is easily dislocated and deformed when the cable is bent, and is prone to collision and bending, resulting in structural damage, is convenient for cable sheath repair and production, and more effectively saves costs and reduces safety issues. At the same time, corresponding improvements are made to the tensile strength and re-vulcanization of the repair strip to ensure safe and efficient operation of the cable.

[0019] In one preferred embodiment, the antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline polymer produced by Sanmen Huamai Chemical Co., Ltd.

[0020] In a preferred embodiment, the plasticizer is trioctyl trimellitate.

[0021] In a preferred embodiment, the vulcanization temperature of the combination of the vulcanizing agent and the co-vulcanizing agent is 180° C. for 10-15 minutes, or 120° C. for 2-3 hours.

[0022] In a preferred embodiment, the vulcanizing agent is BIBP produced by Changsha West Chemical Co., Ltd.

[0023] In a preferred embodiment, the co-vulcanizing agent is triallyl isocyanurate.

[0024] In one of the preferred embodiments, the reinforcing tensile element is formed by twisting polyester rope, aramid yarn, tear rope and nylon rope, and has a diameter of 1 mm to 3 mm.

[0025] In one of the preferred embodiments, the extrusion molding step includes: after the film enters the barrel of the rubber extruder, the film becomes a viscous flow state, and then a reinforcing tensile element is placed in the center of the mold core, and an insulating rubber sheathed cable repair strip of specific size and geometric cross-section is obtained through extrusion molding by the molding equipment.

[0026] In one preferred embodiment, the extrusion molding step includes: after the film enters the barrel of the rubber extruder, it is gradually pushed toward the head of the machine as the screw rotates, the screw groove is filled with the film, the material begins to be compacted, and due to the gradual shallowing of the screw groove and the resistance of the diverter plate and the head, a very high pressure is formed in the rubber, and the film is pressed very densely. Under the action of the external heating of the barrel and the internal friction heat generated by the mixing and shearing of the screw and the barrel on the material, the temperature of the rubber gradually increases, so that the rubber begins to melt and gradually changes into a viscous flow state; then a polyester rope, aramid yarn, tear rope or nylon rope is placed in the center of the extrusion mold core, and then passed through the molding mold in the head, the material passes through it to obtain a certain cross-sectional geometric shape and size. After cooling, a molded insulating rubber sheath cable repair strip is obtained.

[0027] In one of the preferred embodiments, the cross-section of the repair strip is an isosceles arc trapezoid and a spherical triangle; when the repair sheath is die-cast at high temperature, the edge gaps of the cable can be firmly filled, and the roundness of the cable and the stability of the core structure can be effectively ensured.

[0028] In one of the preferred embodiments, the contour line of the isosceles arc trapezoid is formed by two waists with arcs and two straight lines smoothly connected in sequence; the two waists of the arcs are arranged oppositely, namely the left waist and the right waist, and the two diameters are arranged oppositely, namely the upper base and the lower base. The length of the upper base L1 is 7.7mm, the length of the lower base L2 is 26.78mm, the height H is 16.0mm, the chamfer radius of the upper base R1 is 2.0mm, the chamfer radius of the lower base R2 is 1.0mm, and the waist arc radius R3 is 10.0mm; the contour line of the spherical triangle is composed of three curves with arcs smoothly connected in sequence; the three arcs are arranged relatively, namely arc 1, arc 2, and arc 3, and the arc radii of arc 1 and arc 2 are equal, R1 is 15.0mm, the arc radius of arc 3 is R2 is 50.0mm, the three edge chamfer radii are equal, R3 is 0.5mm, the height H of the spherical triangle is 8.47mm, and the width L is 16.51mm.

[0029] The reasons for setting the above length, width and height are: 1. It is convenient for production enterprises to process, with fewer size specifications, easy to produce and prepare inventory, and reduce production costs; 2. It is convenient for customers to use; 3. This size is determined by combining the cable filling gap area.

[0030] The above-mentioned special-shaped repair strip has a simple appearance and structure, and is easy to extrude into rubber. Its cross-section adopts isosceles arc trapezoid and spherical triangle. When the repair sheath is die-cast at high temperature, it can firmly fill the edge gap of the cable, and can effectively ensure the roundness of the cable and the stability of the core structure. If plastic particles are used for filling, the gap cannot be fully filled because there are gaps between the plastic particles. However, when using isosceles arc trapezoid and spherical triangle repair strips, because the edges have edges, the edges can be squeezed into the edge gaps during die-casting. This can fully fill the cable gaps, and the rubber strips are easier to carry and store than plastic particles. Isosceles arc trapezoidal structure repair strips are mainly used for conductor cross-sectional areas of 95mm 2 It is used for sheath repair of cables with a conductor cross-sectional area of ​​95mm2 or less. Because the cable specifications are large, the isosceles arc trapezoidal structure repair strip can be used to fill large gaps. The spherical triangle structure repair strip is mainly used for sheath repair of cables with a conductor cross-sectional area of ​​95mm2 or less. Because the cable specifications are small, the spherical triangle structure repair strip can not only fill the gaps, but also save materials.

[0031] In one preferred embodiment, after the repair strip is vulcanized and pressed, the tensile strength can reach above 11.0 MPa. After the repair strip is vulcanized and pressed, the performance of the cable sheath and the repair strip is almost the same as before the repair, so the repaired cable has the same tensile and wear resistance as the unused cable.

[0032] In one preferred embodiment, the Shore hardness of the repair strip is 55±5 A. The Shore hardness of the repair strip is equal to the hardness of the sheath, which is 55±5 A, and the material properties are almost the same, so the repair strip has the same performance as the sheath.

[0033] The present invention also claims a method for using the insulating rubber sheathed cable repair strip, comprising the following steps:

[0034] 1. After repairing and cleaning the damaged sheath on the insulated rubber sheathed cable, insert the repair strip into the gap or the gap of the cable core, wrap it with a wrapping tape, and wrap the tape and high-temperature resistant PP tape around the outer periphery of the cable core in turn;

[0035] 2. Put the wound insulating rubber sheathed cable into the tubular mold cavity, pressurize it, and vulcanize it at 180-200°C for 20-30 minutes to obtain a repaired insulating rubber sheathed cable.

[0036] The present invention also claims to protect the application of the insulating rubber sheathed cable repair strip in repairing cables.

[0037] Therefore, compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The repair strip is designed to be re-vulcanizable, which can effectively ensure the roundness of the cable and the stability of the core wire structure during use, and solve the problem that the core wire is easily dislocated and deformed when the cable is bent, and is prone to collision and bending, which leads to structural damage. It is convenient for cable sheath repair and production, more effectively saves costs and reduces safety issues. At the same time, corresponding improvements have been made to the tensile strength and re-vulcanization of the repair strip to ensure safe and efficient operation of the cable.

[0039] 2. Extend the service life of mining cables, improve safety and reduce costs.

[0040] 3. The repair strip has environmentally friendly flame retardant properties and can pass the performance tests of GB / T 18380.12 and RoHS.

[0041] 4. Compared with ordinary filling strips, the repair strips are vulcanizable on the one hand, and their hardness is much lower than that of the filling strips on the other hand. There are two types of filling strips that do not have vulcanizable properties. The first type has been vulcanized, and the second type cannot be vulcanized at all. The first reason is that the vulcanized filling strips have high hardness and are not easy to compress and deform during use, and cannot fill the cable fully. The second reason is that the filling strips that cannot be vulcanized at all cannot meet the performance requirements before repair after use, such as physical and mechanical properties, thermal aging properties, etc. At the same time, the filling strips with too high hardness will affect the performance of the final cable. The above reasons lead to that ordinary filling strips cannot be used to repair cables. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a structural principle diagram of the insulating rubber sheathed cable repair strip of the present invention;

[0043] Figure 2 is a cross-sectional view of an insulating rubber sheathed cable repair strip according to embodiment 1 of the present invention;

[0044] Figure 3 is a cross-sectional view of an insulating rubber sheathed cable repair strip according to embodiment 2 of the present invention;

[0045] In the figure 1 - reinforcing tensile element, 2 - revulcanizable rubber strip. DETAILED DESCRIPTION

[0046] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0047] Example 1

[0048] like Figure 1-3 As shown, an insulating rubber sheath cable repair strip comprises a reinforcing tensile element and a re-vulcanizable rubber strip, wherein the reinforcing tensile element is arranged at the center of the re-vulcanizable rubber strip;

[0049] The re-vulcanizable rubber strip comprises: 86 parts of chlorinated polyethylene (CPE3000), 10 parts of ethylene propylene diene monomer rubber (KEP210), 10 parts of magnesium oxide, 7 parts of flame retardant, 0.7 parts of antioxidant, 10 parts of carbon black N330, 13 parts of white carbon black, 18 parts of clay, 10 parts of talc, 13 parts of plasticizer TOTM, 10 parts of diisooctyl adipate (DOA), 0.7 parts of paraffin, 0.9 parts of polyethylene wax, 2.7 parts of co-vulcanizing agent, and 1.8 parts of vulcanizing agent.

[0050] The antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline polymer from Sanmen Huamai Chemical Co., Ltd. The plasticizer is trioctyl trimellitate. The vulcanizer is BIBP from Changsha West Chemical Co., Ltd. The co-vulcanizer is triallyl isocyanurate. The reinforced tensile element is twisted together by polyester rope, aramid yarn, tear rope and nylon rope, and has a diameter of 1.5 mm.

[0051] The preparation method of the re-vulcanizable rubber strip comprises the following steps:

[0052] Step 1, adding chlorinated polyethylene and EPDM rubber into an internal mixer and plasticizing for 2-3 minutes;

[0053] Step 2, add other components except the vulcanizing agent and the co-vulcanizing agent, mix for 3-4 minutes, and discharge at 90-100°C;

[0054] Step 3, the discharged mixed rubber material is thinned once on the open mill and then turned over 2-3 times on the rubber turning machine, then calendered on the open mill, and cooled on the cooling roller to form a sheet;

[0055] Step 4: The semi-finished product is placed for 10-12 hours after being produced, and then put into an internal mixer for mixing, and a vulcanizing agent and a co-vulcanizing agent are added at a temperature of 80-90° C., mixed for 1 minute, and discharged to discharge the mixed rubber material;

[0056] Step 5, the mixed rubber material is thinned once on the open mill, then turned over 2-3 times on the rubber turning machine, and then calendered on the open mill, and then packed into boxes after passing through the cooling roller talcum powder box to obtain the film;

[0057] Step 6: Extruding the film at 70-90° C. to obtain an insulating rubber sheathed cable repair strip.

[0058] The steps of extrusion molding include: after the rubber sheet enters the barrel of the rubber extruder, it is gradually pushed toward the die head as the screw rotates, the screw groove is filled with the rubber sheet, and the material begins to be compacted. As the screw groove gradually becomes shallower, and the resistance of the diverter plate and the die head, a very high pressure is formed in the rubber, pressing the rubber sheet very densely. Under the action of the internal friction heat generated by the external heating of the barrel and the mixing and shearing of the screw and the barrel on the material, the temperature of the rubber material gradually increases, so that the rubber material begins to melt and gradually changes into a viscous flow state; then a reinforcing tensile element made of polyester rope, aramid yarn, tear rope, and nylon rope is placed in the center of the extrusion mold core, and then passed through the molding mold in the die head, the material passes through it to obtain a certain cross-sectional geometric shape and size. After cooling, the molded insulating rubber sheath cable repair strip is obtained. The cross section of the insulating rubber sheath cable repair strip is an isosceles arc trapezoid. The contour of the isosceles arc trapezoid is formed by two waists with arcs and two straight lines connected smoothly in sequence; the two waists of the arcs are arranged relatively, namely the left waist and the right waist, and the two diameters are arranged relatively, namely the upper base and the lower base. The upper base length L1 is 7.7mm, the lower base length L2 is 26.78mm, the height H is 16.0mm, the upper base chamfer radius R1 is 2.0mm, the lower base chamfer radius R2 is 1.0mm, and the waist arc radius R3 is 10.0mm.

[0059] Example 2

[0060] An insulating rubber sheathed cable repair strip comprises a reinforcing tensile element and a re-vulcanizable rubber strip, wherein the reinforcing tensile element is arranged at the center of the re-vulcanizable rubber strip;

[0061] The re-vulcanizable rubber strip comprises: 90 parts of chlorinated polyethylene (CPE3000), 14 parts of ethylene propylene diene monomer rubber (KEP210), 14 parts of magnesium oxide, 9 parts of flame retardant, 0.7 parts of antioxidant, 14 parts of carbon black N330, 17 parts of white carbon black, 22 parts of clay, 10 parts of talc, 13 parts of plasticizer TOTM, 10 parts of diisooctyl adipate (DOA), 0.9 parts of paraffin, 1.1 parts of polyethylene wax, 2.7 parts of co-vulcanizing agent, and 2.2 parts of vulcanizing agent.

[0062] The antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline polymer from Sanmen Huamai Chemical Co., Ltd. The plasticizer is trioctyl trimellitate. The vulcanizer is BIBP from Changsha West Chemical Co., Ltd. The co-vulcanizer is triallyl isocyanurate. The reinforced tensile element is twisted together by polyester rope, aramid yarn, tear rope and nylon rope, and has a diameter of 1.5 mm.

[0063] The preparation method of the re-vulcanizable rubber strip comprises the following steps:

[0064] Step 1, adding chlorinated polyethylene and EPDM rubber into an internal mixer and plasticizing for 2-3 minutes;

[0065] Step 2, add other components except the vulcanizing agent and the co-vulcanizing agent, mix for 3-4 minutes, and discharge at 90-100°C;

[0066] Step 3, the discharged mixed rubber material is thinned once on the open mill and then turned over 2-3 times on the rubber turning machine, then calendered on the open mill, and cooled on the cooling roller to form a sheet;

[0067] Step 4: The semi-finished product is placed for 10-12 hours after being produced, and then put into an internal mixer for mixing, and a vulcanizing agent and a co-vulcanizing agent are added at a temperature of 80-90° C., mixed for 1 minute, and discharged to discharge the mixed rubber material;

[0068] Step 5, the mixed rubber material is thinned once on the open mill, then turned over 2-3 times on the rubber turning machine, and then calendered on the open mill, and then packed into boxes after passing through the cooling roller talcum powder box to obtain the film;

[0069] Step 6: Extruding the film at 70-90° C. to obtain an insulating rubber sheathed cable repair strip.

[0070] The steps of extrusion molding include: after the rubber sheet enters the barrel of the rubber extruder, it is gradually pushed toward the die head as the screw rotates, the screw groove is filled with the rubber sheet, and the material begins to be compacted. As the screw groove gradually becomes shallower, and the resistance of the diverter plate and the die head, a very high pressure is formed in the rubber, pressing the rubber sheet very densely. Under the action of the internal friction heat generated by the external heating of the barrel and the mixing and shearing of the screw and the barrel on the material, the temperature of the rubber material gradually increases, so that the rubber material begins to melt and gradually changes into a viscous flow state; then a reinforcing tensile element made of polyester rope, aramid yarn, tear rope, and nylon rope is placed in the center of the extrusion mold core, and then passed through the molding mold in the die head, the material passes through it and obtains a certain cross-sectional geometric shape and size. After cooling, the molded insulating rubber sheath cable repair strip is obtained.

[0071] The cross section of the re-vulcanizable rubber strip is a spherical triangle. The contour line of the spherical triangle is formed by three curves with arcs connected in sequence smoothly; the three arcs are arranged relatively, namely arc 1, arc 2, and arc 3, the arc radius of arc 1 and arc 2 is equal to R1 of 15.0mm, the arc radius of arc 3 is R2 of 50.0mm, the three edge chamfer radii are equal to R3 of 0.5mm, the height H of the spherical triangle is 8.47mm, and the width L is 16.51mm.

[0072] The special-shaped repair strip has a simple appearance and structure, and is easy to extrude into rubber. Its cross-section adopts isosceles arc trapezoid and spherical triangle. When the repair sheath is die-cast at high temperature, it can firmly fill the edge gap of the cable, which can effectively ensure the roundness of the cable and the stability of the core structure. If rubber particles are used for filling, the gap cannot be fully filled because there are gaps between the rubber particles. However, when using isosceles arc trapezoid and spherical triangle repair strips, because the edges have edges, the edges can be squeezed into the edge gaps during die-casting. This can fully fill the cable gaps, and the rubber strips are easier to carry and store than rubber particles. Isosceles arc trapezoidal structure repair strips are mainly used for conductor cross-sectional areas of 95mm 2 For sheath repair of cables above 95mm, due to the large cable specifications, the isosceles arc trapezoidal structure repair strip can fill the large gap. The spherical triangle structure repair strip is mainly used for conductor cross-sectional area 95mm 2 The following cables are used for sheath repair. Because the cable specifications are small, the use of spherical triangular structure repair strips can not only fill the gaps, but also save materials.

[0073] The insulating rubber sheathed cable repair strips of Example 1 and Example 2 were tested, and the performance was as follows:

[0074] 1. Hardness test

[0075] thickness

[0076] When measuring hardness with a portable hardness tester, the sample thickness should be at least 6mm. For thin sheets less than 6mm thick, in order to obtain sufficient test thickness, the sample can be composed of no more than 3 sheets, and the thickness of each sheet should not be less than 2mm. However, the measurement results obtained by this method may be inconsistent with the measurement results of a single layer. The shapes and sizes of the samples used for comparison purposes should be similar.

[0077] surface

[0078] The sample size should be large enough, the measuring point should be at least 12 mm away from any edge of the sample, and the sample surface in contact with the pressure foot should be flat. It is not possible to obtain satisfactory measurement results on curved, uneven or rough surfaces with portable rubber international hardness testers. However, they also have special applications, such as ISO 7267-1 for the hardness determination of rubber rollers. The limitations of these special applications should be clearly understood.

[0079] adjust

[0080] Before the test, the sample should be conditioned at standard laboratory temperature for at least 1 hour in accordance with GB / T 2941. Any single or series of tests for comparison purposes should always use the same temperature.

[0081] program

[0082] General Procedures

[0083] Place the sample on a flat, hard, rigid surface. Hold the durometer so that the center of the end of the indenter is at least 12 mm away from each edge of the sample. Press the indenter onto the sample as quickly and without vibration as possible. Ensure that the indenter is parallel to the sample surface and the indenter is perpendicular to the rubber surface.

[0084] Test force holding time

[0085] Apply enough pressure to keep the pressure foot in close contact with the sample surface, and then read the reading at the specified time. The standard test force holding time for vulcanized rubber is 3s, and for thermoplastic rubber is 15s. If other test force holding times are used, it must be stated in the test report. Unknown types of rubber are treated as vulcanized rubber.

[0086] Number of measurements

[0087] Carry out 5 measurements at different points on the sample surface, with the interval between any two measuring points being at least 6 mm, and then take the median of the 5 measurement results.

[0088] The Shore hardness of the rubber insulated cable repair strip is 50A. The Shore hardness of the ordinary rubber filling strip tested in the same way is 68A. The hardness of the ordinary rubber filling strip after vulcanization is too high and cannot be used as a repair strip.

[0089] Other properties of the test repair strip are as follows: physical and mechanical properties: tensile strength before aging, minimum 11.0MPa, elongation at break before aging, minimum 250%; tensile strength after aging, minimum 8.5MPa; elongation at break after aging, minimum 125%; aging conditions: 120±2℃*240h.

[0090] The insulating rubber sheath cable repair strips of Example 1 and Example 2 are applied to the damaged cables, and the repair process is as follows:

[0091] Repair model specification MY 3×50+1×25 mining cable, the repair strip specifications are isosceles arc trapezoid and spherical triangle, repair process: 1. Set the temperature and time according to the vulcanization system of the rubber strip (180-200℃ / 30min). 2. Repair the damaged sheath with a utility knife, and then use rubber ink thinner to wipe the repaired part, especially the joint should be fully treated. 3. Plug the repair strip into the gap or the gap of the cable core. 4. Wrap it with non-woven fabric or other suitable wrapping tape to prevent looseness, 5, and then wrap the CR material tape around the cable core, 6. Wrap the CR material tape with high temperature resistant PP tape. And put it into a tubular mold cavity slightly smaller than the wire diameter, lock the upper and lower molds, and let the repaired position have a certain pressure. Note that the mold cavity diameter is slightly smaller than the wire diameter by 0.1~0.2mm. 7. When the vulcanization time is up, take out the product. If a small amount of rubber overflows, trim it with a sharp blade and wipe it off with a thinner.

[0092] The physical and mechanical properties of the repaired cable are the same as or equivalent to those before the repair.

[0093] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the embodiments made by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. An insulating rubber sheathed cable repair strip, It is characterized in that It comprises a reinforcing tensile element and a re-vulcanizable rubber strip, wherein the reinforcing tensile element is arranged at the center of the re-vulcanizable rubber strip; The re-vulcanizable rubber strip comprises: 86-90 parts of chlorinated polyethylene, 10-14 parts of ethylene propylene diene rubber, 10-14 parts of magnesium oxide, 7-9 parts of flame retardant, 0.7-0.9 parts of antioxidant, 10-14 parts of carbon black, 13-17 parts of white carbon black, 18-22 parts of clay, 10-14 parts of talc, 13-17 parts of plasticizer, 10-14 parts of diisooctyl adipate, 0.7-0.9 parts of paraffin wax, 0.9-1.1 parts of polyethylene wax, 2.3-2.7 parts of vulcanizing agent, and 1.8-2.2 parts of vulcanizing agent; The preparation method of the re-vulcanizable rubber strip comprises the following steps: Step 1, adding chlorinated polyethylene and EPDM rubber into an internal mixer and plasticizing for 2-3 minutes; Step 2, add other components except the vulcanizing agent and the co-vulcanizing agent, mix for 3-4 minutes, and discharge at 90-100°C; Step 3, the discharged mixed rubber material is thinned once on the open mill and then turned over 2-3 times on the rubber turning machine, then calendered on the open mill, and cooled on the cooling roller to form a sheet; Step 4: The semi-finished product is placed for 10-12 hours after being produced, and then put into an internal mixer for mixing, and a vulcanizing agent and a co-vulcanizing agent are added at a temperature of 80-90° C., mixed for 1 minute, and discharged to discharge the mixed rubber material; Step 5, the mixed rubber material is thinned once on the open mill, then turned over 2-3 times on the rubber turning machine, and then calendered on the open mill, and then packed into boxes after passing through the cooling roller talcum powder box to obtain the film; Step 6, extruding the film at 70-90° C. to obtain an insulating rubber sheathed cable repair strip; The antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline polymer; the plasticizer is trioctyl trimellitate; the vulcanization temperature of the combination of the vulcanizer and the co-vulcanizer is 10-15 minutes at 180°C, or 2-3 hours at 120°C; the cross-section of the insulating rubber sheathed cable repair strip is an isosceles arc trapezoid and a spherical triangle.

2. The insulating rubber sheathed cable repair strip according to claim 1, It is characterized in that The vulcanizing agent is BIBP, and the co-vulcanizing agent is triallyl isocyanurate.

3. The insulating rubber sheathed cable repair strip according to claim 1, It is characterized in that The reinforcing tensile element is formed by twisting polyester rope, aramid yarn, tear rope and nylon rope, and has a diameter of 1mm to 3mm.

4. The insulating rubber sheathed cable repair strip according to claim 1, It is characterized in that The steps of extrusion molding include: after the rubber sheet enters the barrel of the rubber extruder, the rubber sheet becomes a viscous flow state, and then a reinforcing tensile element is placed in the center of the mold core, and an insulating rubber sheathed cable repair strip of a specific size and geometric cross-section is obtained through extrusion molding by the molding equipment.

5. The insulating rubber sheathed cable repair strip according to any one of claims 1 to 4, It is characterized in that After the insulating rubber sheath cable repair strip is vulcanized and pressed, the tensile strength is above 11.0 MPa and the Shore hardness is 55±5A.

6. A method for using the insulating rubber sheathed cable repair strip according to any one of claims 1 to 5, It is characterized in that The following steps are involved: (1) After repairing and cleaning the damaged sheath on the insulated rubber sheathed cable, insert the repair strip into the gap or the gap of the cable core wire, wrap it with a wrapping tape, and wrap the tape and high-temperature resistant PP tape around the outer periphery of the cable core in sequence; (2) Place the wound insulating rubber sheathed cable into a tubular mold cavity, pressurize, and vulcanize at 180-200°C for 20-30 minutes to obtain a repaired insulating rubber sheathed cable.

7. Use of the insulating rubber sheathed cable repair strip according to any one of claims 1 to 5 in repairing cables.

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