1. A durable safety cable, comprising:

an inner core composed of a wire group;

the coating layer comprises the following components in parts by weight: 40-50 parts of ethylene propylene diene monomer, 30-40 parts of nitrile rubber, 3-8 parts of polysulfone film, 30-40 parts of silicone rubber, 10-20 parts of phenolic resin, 10-15 parts of polyvinyl chloride resin, 2-5 parts of chitosan and 8-15 parts of flame retardant.

2. The robust security cable of claim 1, wherein said conductor sets are twisted from a plurality of copper wires.

3. A durable safety cable according to claim 1, wherein the coating comprises the following ingredients in parts by weight: 45 parts of ethylene propylene diene monomer, 35 parts of nitrile rubber, 5 parts of polysulfone membrane, 35 parts of silicon rubber, 15 parts of phenolic resin, 12 parts of polyvinyl chloride resin, 3 parts of chitosan and 11 parts of flame retardant.

4. A durable safety cable according to claim 1 or 3, wherein the flame retardant is one or more of antimony trioxide, melamine phosphate.

5. A method of making a durable safety cable according to any one of claims 1 to 4, comprising the steps of:

s1: uniformly coating a wire drawing liquid on the surface of a copper bar, drawing the copper bar into a copper wire with the thickness of 0.52-1.25 mm by using a wire drawing machine, and simultaneously carrying out annealing treatment;

s2: stranding a plurality of copper wires to obtain a wire group, obtaining an inner core, and then heating the inner core by passing through a high-frequency coil;

s3: adding ethylene propylene diene monomer, nitrile rubber and silicone rubber into a rubber mixing mill, controlling the roll temperature to be 35-50 ℃, carrying out pressure refining for 5-15 min, then introducing the materials into a plastic extruding machine, adding a polysulfone film, controlling the temperature to be 80-100 ℃, carrying out extrusion coating on the upper layer on the outer side of the inner core, respectively carrying out hot water cooling and cold water cooling, and carrying out air cooling blow-drying to form an inner treatment layer;

s4: pressing a plurality of pretreatment traces on the inner treatment layer, cooling with hot water and cooling with cold water, adding phenolic resin into an extruding machine, crushing chitosan and adding the crushed chitosan to the pretreatment traces after extruding, and extruding polyvinyl chloride resin by the extruding machine to wrap the outer ring of the upper treatment layer to completely wrap the pretreatment traces to form an outer treatment layer;

s5: and (4) extruding and wrapping the flame retardant on the outer treatment layer through an extrusion wrapping process to obtain the durable safe cable.

6. The method as claimed in claim 5, wherein in the step of S2, at least one of the copper wires is S-shaped and at least two of the copper wires are connected end to end.

7. The method for preparing a durable safety cable according to claim 5, wherein the high frequency coil heating temperature in S2 is 80-160 ℃.

8. The method of claim 5, wherein in step S2, each copper wire is ground by a grinding machine before stranding.

9. The method as claimed in claim 5, wherein the cooling temperature of the hot water is controlled to be 45-50 ℃ and the cooling temperature of the cold water is controlled to be 5-15 ℃ in S3 and S4.

10. The method as claimed in claim 5, wherein the pre-treatment mark is opened in a circular ring shape/S shape in S4.

Background

A cable is an assembly for connecting two devices to transmit electrical signals, and is formed by bonding, twisting, or weaving two or more wires together. The cable has a wide range of applications and each application requires a special purpose, which is a wire product with large functions for transmitting electric energy, electric signals and realizing electromagnetic energy conversion.

An electric cable generally comprises a cable core for transmitting electric power or electric signals and a sheath for protecting and insulating. Cables having only one core and a relatively small diameter are generally referred to as wires. And the electric wire without the insulating sheath is called a bare wire. The cable core in the cable is made of metal materials with good electric conductivity, and usually copper with good electric conductivity or aluminum with low cost is used.

The tensile strength change rate and the elongation at break rate of the existing cable are poor in performance, and the performance of an alternating current withstand voltage test is also relatively deficient.

Therefore, we propose a durable safety cable to solve the above problems.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provides a durable safety cable.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a durable safety cable, which comprises: an inner core composed of a wire group; the coating layer comprises the following components in parts by weight: 40-50 parts of ethylene propylene diene monomer, 30-40 parts of nitrile rubber, 3-8 parts of polysulfone film, 30-40 parts of silicone rubber, 10-20 parts of phenolic resin, 10-15 parts of polyvinyl chloride resin, 2-5 parts of chitosan and 8-15 parts of flame retardant.

Preferably, the wire set is stranded from a plurality of copper wires.

Preferably, the coating layer comprises the following components in parts by weight: 45 parts of ethylene propylene diene monomer, 35 parts of nitrile rubber, 5 parts of polysulfone membrane, 35 parts of silicon rubber, 15 parts of phenolic resin, 12 parts of polyvinyl chloride resin, 3 parts of chitosan and 11 parts of flame retardant.

Preferably, the flame retardant is one or more of antimony trioxide and melamine phosphate.

In another aspect of the present invention, a method for preparing a durable safety cable is provided, comprising the steps of:

s1: uniformly coating a wire drawing liquid on the surface of a copper bar, drawing the copper bar into a copper wire with the thickness of 0.52-1.25 mm by using a wire drawing machine, and simultaneously carrying out annealing treatment;

s2: stranding a plurality of copper wires to obtain a wire group, obtaining an inner core, and then heating the inner core by passing through a high-frequency coil;

s3: adding ethylene propylene diene monomer, nitrile rubber and silicone rubber into a rubber mixing mill, controlling the roll temperature to be 35-50 ℃, carrying out pressure refining for 5-15 min, then introducing the materials into a plastic extruding machine, adding a polysulfone film, controlling the temperature to be 80-100 ℃, carrying out extrusion coating on the upper layer on the outer side of the inner core, respectively carrying out hot water cooling and cold water cooling, and carrying out air cooling blow-drying to form an inner treatment layer;

s4: pressing a plurality of pretreatment traces on the inner treatment layer, cooling with hot water and cooling with cold water, adding phenolic resin into an extruding machine, crushing chitosan and adding the crushed chitosan to the pretreatment traces after extruding, and extruding polyvinyl chloride resin by the extruding machine to wrap the outer ring of the upper treatment layer to completely wrap the pretreatment traces to form an outer treatment layer;

s5: and (4) extruding and wrapping the flame retardant on the outer treatment layer through an extrusion wrapping process to obtain the durable safe cable.

Preferably, in S2, in the process of stranding a plurality of copper wires, at least one of the copper wires is S-shaped, and at least two of the copper wires are connected end to end.

Preferably, in S2, the high-frequency coil heating temperature is 80 to 160 ℃.

Preferably, in S2, each copper wire is polished by a polishing machine before stranding.

Preferably, in S3 and S4, the cooling temperature of hot water is controlled to be 45-50 ℃, and the cooling temperature of cold water is controlled to be 5-15 ℃.

Preferably, in S4, the pretreatment mark is opened in a circular ring shape/S shape.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, the cable is prepared and produced by splitting the cable into the inner core and the coating layer, when the coating layer is applied to ethylene propylene diene monomer, nitrile butadiene rubber and silicon rubber, the polysulfone film is arranged in the coating layer, so that the three are melted alternately after a rubber mixing machine, the forming state of the three is better, and the hydrocarbon-based chain link in the polysulfone film also improves the tensile strength of the finally obtained cable and further improves the elongation at break of the cable.

2. According to the invention, after the inner treatment layer is obtained by using a plurality of rubbers, the inner treatment layer is further coated by using the phenolic resin and the polyvinyl chloride resin, and the chitosan is arranged between the phenolic resin and the polyvinyl chloride resin, so that the forming of the outer treatment layer is more stable, and the intermediate layer formed by the chitosan is tightly embedded on the basis of the outer treatment layer formed by the resins, so that the finally obtained cable has better performance in an alternating current withstand voltage test.

3. When the inner core is processed, the shape of the lead group is limited, the stability of the inner core is stronger, and the pretreatment traces are arranged on the inner treatment layer, so that the outer treatment layer is more stable and compact in further coating, and the quality of the finally obtained cable finished product is improved.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control. When "mass, concentration, temperature, time, or other value or parameter is expressed as a range, preferred range, or as a range defined by a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, a range of 1 to 50 should be understood to include any number, combination of numbers, or subrange selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50, and all fractional values between the above integers, e.g., 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, and 1.9. With respect to sub-ranges, specifically consider "nested sub-ranges" that extend from any endpoint within the range. For example, nested sub-ranges of exemplary ranges 1-50 may include 1-10, 1-20, 1-30, and 1-40 in one direction, or 50-40, 50-30, 50-20, and 50-10 in another direction. "

The present invention is further illustrated below with reference to specific examples in which various processes and methods not described in detail are conventional methods well known in the art. Materials, reagents, devices, instruments, apparatuses and the like used in the following examples are commercially available unless otherwise specified.

Example one

A durable safety cable includes an inner core composed of a conductor set; the coating layer comprises the following components in parts by weight: 40 parts of ethylene propylene diene monomer, 30 parts of nitrile rubber, 3 parts of polysulfone membrane, 30 parts of silicon rubber, 10 parts of phenolic resin, 10 parts of polyvinyl chloride resin, 2 parts of chitosan and 8 parts of flame retardant.

Wherein, the wire group is stranded by a plurality of copper wires, and the fire retardant is one or more of antimony trioxide and melamine phosphate.

In an embodiment, a method for manufacturing a durable safety cable is further provided, including the steps of:

s1: uniformly coating a wire drawing liquid on the surface of a copper bar, drawing the copper bar into a copper wire with the thickness of 0.52mm by using a wire drawing machine, and simultaneously carrying out annealing treatment;

s2: before stranding, polishing each copper wire by using a polisher, stranding a plurality of copper wires to obtain a wire group to obtain an inner core, and then penetrating the inner core through a high-frequency coil for heating, wherein the heating temperature of the high-frequency coil is 80 ℃;

s3: adding ethylene propylene diene monomer, nitrile rubber and silicone rubber into a rubber mixing mill, controlling the roll temperature to be 35 ℃, carrying out pressure refining for 5min, then introducing the materials into a plastic extruding machine, adding a polysulfone film, controlling the temperature to be 80 ℃, carrying out extrusion coating on the upper layer on the outer side of the inner core, respectively carrying out hot water cooling and cold water cooling, and carrying out air cooling blow-drying to form an inner treatment layer, controlling the hot water cooling temperature to be 45 ℃, and controlling the cold water cooling temperature to be 5 ℃;

s4: pressing a plurality of pretreatment traces on the inner treatment layer, wherein the pretreatment traces are arranged in a circular ring shape/S shape, performing hot water cooling and cold water cooling, then adding phenolic resin into a plastic extruding machine, crushing chitosan and adding the crushed chitosan into the pretreatment traces, then extruding polyvinyl chloride resin on an outer ring of the upper treatment layer by using the plastic extruding machine to completely wrap the pretreatment traces to form an outer treatment layer, wherein the hot water cooling temperature is controlled at 45 ℃, and the cold water cooling temperature is controlled at 5 ℃;

s5: and (4) extruding and wrapping the flame retardant on the outer treatment layer through an extrusion wrapping process to obtain the durable safe cable.

Wherein, in the process of stranding a plurality of copper wires, at least one copper wire is S-shaped, and at least two copper wires are connected end to end.

Example two

A durable safety cable includes an inner core composed of a conductor set; the coating layer comprises the following components in parts by weight: 43 parts of ethylene propylene diene monomer, 34 parts of nitrile rubber, 5 parts of polysulfone membrane, 33 parts of silicone rubber, 14 parts of phenolic resin, 12 parts of polyvinyl chloride resin, 3 parts of chitosan and 11 parts of flame retardant.

Wherein, the wire group is stranded by a plurality of copper wires, and the fire retardant is one or more of antimony trioxide and melamine phosphate.

In an embodiment, a method for manufacturing a durable safety cable is further provided, including the steps of:

s1: uniformly coating a wire drawing liquid on the surface of a copper bar, drawing the copper bar into a copper wire with the thickness of 0.67mm by using a wire drawing machine, and simultaneously carrying out annealing treatment;

s2: before stranding, polishing each copper wire by using a polisher, stranding a plurality of copper wires to obtain a wire group to obtain an inner core, and then penetrating the inner core through a high-frequency coil for heating, wherein the heating temperature of the high-frequency coil is 110 ℃;

s3: adding ethylene propylene diene monomer, nitrile rubber and silicone rubber into a rubber mixing mill, controlling the roll temperature to be 40 ℃, carrying out pressure refining for 8min, then introducing the materials into a plastic extruding machine, adding a polysulfone film, controlling the temperature to be 85 ℃, carrying out extrusion coating on the upper layer on the outer side of the inner core, respectively carrying out hot water cooling and cold water cooling, and carrying out air cooling blow-drying to form an inner treatment layer, controlling the hot water cooling temperature to be 47 ℃, and controlling the cold water cooling temperature to be 8 ℃;

s4: pressing a plurality of pretreatment traces on the inner treatment layer, wherein the pretreatment traces are arranged in a circular ring shape/S shape, performing hot water cooling and cold water cooling, then adding phenolic resin into a plastic extruding machine, crushing chitosan and adding the chitosan into the pretreatment traces after extruding, then extruding polyvinyl chloride resin on an outer ring of the upper treatment layer by using the plastic extruding machine to completely wrap the pretreatment traces to form an outer treatment layer, wherein the hot water cooling temperature is controlled at 47 ℃, and the cold water cooling temperature is controlled at 8 ℃;

s5: and (4) extruding and wrapping the flame retardant on the outer treatment layer through an extrusion wrapping process to obtain the durable safe cable.

Wherein, in the process of stranding a plurality of copper wires, at least one copper wire is S-shaped, and at least two copper wires are connected end to end.

EXAMPLE III

A durable safety cable includes an inner core composed of a conductor set; the coating layer comprises the following components in parts by weight: 48 parts of ethylene propylene diene monomer, 38 parts of nitrile rubber, 7 parts of polysulfone membrane, 37 parts of silicone rubber, 18 parts of phenolic resin, 14 parts of polyvinyl chloride resin, 4 parts of chitosan and 13 parts of flame retardant.

Wherein, the wire group is stranded by a plurality of copper wires, and the fire retardant is one or more of antimony trioxide and melamine phosphate.

In an embodiment, a method for manufacturing a durable safety cable is further provided, including the steps of:

s1: uniformly coating a wire drawing liquid on the surface of a copper bar, drawing the copper bar into a copper wire with the thickness of 1.13mm by using a wire drawing machine, and simultaneously carrying out annealing treatment;

s2: before stranding, polishing each copper wire by using a polisher, stranding a plurality of copper wires to obtain a wire group to obtain an inner core, and then penetrating the inner core through a high-frequency coil for heating, wherein the heating temperature of the high-frequency coil is 140 ℃;

s3: adding ethylene propylene diene monomer, nitrile rubber and silicone rubber into a rubber mixing mill, controlling the roll temperature to be 45 ℃, carrying out pressure refining for 13min, then introducing the materials into a plastic extruding machine, adding a polysulfone film, controlling the temperature to be 95 ℃, carrying out extrusion coating on the upper layer on the outer side of the inner core, respectively carrying out hot water cooling and cold water cooling, and carrying out air cooling blow-drying to form an inner treatment layer, controlling the hot water cooling temperature to be 49 ℃, and controlling the cold water cooling temperature to be 13 ℃;

s4: pressing a plurality of pretreatment traces on the inner treatment layer, wherein the pretreatment traces are arranged in a circular ring shape/S shape, performing hot water cooling and cold water cooling, then adding phenolic resin into a plastic extruding machine, crushing chitosan and adding the chitosan into the pretreatment traces after extruding, then extruding polyvinyl chloride resin on an outer ring of the upper treatment layer by using the plastic extruding machine to completely wrap the pretreatment traces to form an outer treatment layer, wherein the hot water cooling temperature is controlled at 49 ℃, and the cold water cooling temperature is controlled at 13 ℃;

s5: and (4) extruding and wrapping the flame retardant on the outer treatment layer through an extrusion wrapping process to obtain the durable safe cable.

Wherein, in the process of stranding a plurality of copper wires, at least one copper wire is S-shaped, and at least two copper wires are connected end to end.

Example four

A durable safety cable includes an inner core composed of a conductor set; the coating layer comprises the following components in parts by weight: 50 parts of ethylene propylene diene monomer, 40 parts of nitrile rubber, 8 parts of polysulfone membrane, 40 parts of silicon rubber, 20 parts of phenolic resin, 15 parts of polyvinyl chloride resin, 5 parts of chitosan and 15 parts of flame retardant.

Wherein, the wire group is stranded by a plurality of copper wires, and the fire retardant is one or more of antimony trioxide and melamine phosphate.

In an embodiment, a method for manufacturing a durable safety cable is further provided, including the steps of:

s1: uniformly coating a wire drawing liquid on the surface of a copper bar, drawing the copper bar into a copper wire with the thickness of 1.25mm by using a wire drawing machine, and simultaneously carrying out annealing treatment;

s2: before stranding, polishing each copper wire by using a polisher, stranding a plurality of copper wires to obtain a wire group to obtain an inner core, and then penetrating the inner core through a high-frequency coil for heating, wherein the heating temperature of the high-frequency coil is 160 ℃;

s3: adding ethylene propylene diene monomer, nitrile rubber and silicone rubber into a rubber mixing mill, controlling the roll temperature to be 50 ℃, carrying out pressure refining for 15min, then introducing the materials into a plastic extruding machine, adding a polysulfone film, controlling the temperature to be 100 ℃, carrying out extrusion coating on the upper layer on the outer side of an inner core, respectively carrying out hot water cooling and cold water cooling, and carrying out air cooling blow-drying to form an inner treatment layer, controlling the hot water cooling temperature to be 50 ℃, and controlling the cold water cooling temperature to be 15 ℃;

s4: pressing a plurality of pretreatment traces on the inner treatment layer, wherein the pretreatment traces are arranged in a circular ring shape/S shape, performing hot water cooling and cold water cooling, then adding phenolic resin into a plastic extruding machine, crushing chitosan and adding the crushed chitosan into the pretreatment traces, then extruding polyvinyl chloride resin on an outer ring of the upper treatment layer by using the plastic extruding machine to completely wrap the pretreatment traces to form an outer treatment layer, wherein the hot water cooling temperature is controlled at 50 ℃, and the cold water cooling temperature is controlled at 15 ℃;

s5: and (4) extruding and wrapping the flame retardant on the outer treatment layer through an extrusion wrapping process to obtain the durable safe cable.

Wherein, in the process of stranding a plurality of copper wires, at least one copper wire is S-shaped, and at least two copper wires are connected end to end.

Comparative example 1

A durable safety cable includes an inner core composed of a conductor set; the coating layer comprises the following components in parts by weight: 50 parts of ethylene propylene diene monomer, 40 parts of nitrile rubber, 40 parts of silicon rubber, 20 parts of phenolic resin, 15 parts of polyvinyl chloride resin, 5 parts of chitosan and 15 parts of flame retardant.

Wherein, the wire group is stranded by a plurality of copper wires, and the fire retardant is one or more of antimony trioxide and melamine phosphate.

In a comparative example, a method of making a durable safety cable is also provided, comprising the steps of:

s1: uniformly coating a wire drawing liquid on the surface of a copper bar, drawing the copper bar into a copper wire with the thickness of 1.25mm by using a wire drawing machine, and simultaneously carrying out annealing treatment;

s2: before stranding, polishing each copper wire by using a polisher, stranding a plurality of copper wires to obtain a wire group to obtain an inner core, and then penetrating the inner core through a high-frequency coil for heating, wherein the heating temperature of the high-frequency coil is 160 ℃;

s3: adding ethylene propylene diene monomer, nitrile rubber and silicone rubber into a rubber mixing mill, controlling the roll temperature to be 50 ℃, carrying out pressure mixing for 15min, then introducing the materials into a plastic extruding machine, carrying out extrusion coating on the upper layer on the outer side of an inner core, respectively carrying out hot water cooling and cold water cooling, and carrying out air cooling blow-drying to form an inner treatment layer, wherein the hot water cooling temperature is controlled to be 50 ℃, and the cold water cooling temperature is controlled to be 15 ℃;

s4: pressing a plurality of pretreatment traces on the inner treatment layer, wherein the pretreatment traces are arranged in a circular ring shape/S shape, performing hot water cooling and cold water cooling, then adding phenolic resin into a plastic extruding machine, crushing chitosan and adding the crushed chitosan into the pretreatment traces, then extruding polyvinyl chloride resin on an outer ring of the upper treatment layer by using the plastic extruding machine to completely wrap the pretreatment traces to form an outer treatment layer, wherein the hot water cooling temperature is controlled at 50 ℃, and the cold water cooling temperature is controlled at 15 ℃;

s5: and (4) extruding and wrapping the flame retardant on the outer treatment layer through an extrusion wrapping process to obtain the durable safe cable.

Wherein, in the process of stranding a plurality of copper wires, at least one copper wire is S-shaped, and at least two copper wires are connected end to end.

Comparative example No. two

A durable safety cable includes an inner core composed of a conductor set; the coating layer comprises the following components in parts by weight: 50 parts of ethylene propylene diene monomer, 40 parts of nitrile rubber, 8 parts of polysulfone membrane, 40 parts of silicone rubber, 20 parts of phenolic resin, 15 parts of polyvinyl chloride resin and 15 parts of flame retardant.

Wherein, the wire group is stranded by a plurality of copper wires, and the fire retardant is one or more of antimony trioxide and melamine phosphate.

In a comparative example, a method of making a durable safety cable is also provided, comprising the steps of:

s1: uniformly coating a wire drawing liquid on the surface of a copper bar, drawing the copper bar into a copper wire with the thickness of 1.25mm by using a wire drawing machine, and simultaneously carrying out annealing treatment;

s2: before stranding, polishing each copper wire by using a polisher, stranding a plurality of copper wires to obtain a wire group to obtain an inner core, and then penetrating the inner core through a high-frequency coil for heating, wherein the heating temperature of the high-frequency coil is 160 ℃;

s3: adding ethylene propylene diene monomer, nitrile rubber and silicone rubber into a rubber mixing mill, controlling the roll temperature to be 50 ℃, carrying out pressure refining for 15min, then introducing the materials into a plastic extruding machine, adding a polysulfone film, controlling the temperature to be 100 ℃, carrying out extrusion coating on the upper layer on the outer side of an inner core, respectively carrying out hot water cooling and cold water cooling, and carrying out air cooling blow-drying to form an inner treatment layer, controlling the hot water cooling temperature to be 50 ℃, and controlling the cold water cooling temperature to be 15 ℃;

s4: pressing a plurality of pretreatment marks on the inner treatment layer, wherein the pretreatment marks are arranged in a ring shape/S shape, performing hot water cooling and cold water cooling, adding phenolic resin into a plastic extruding machine, extruding polyvinyl chloride resin by the plastic extruding machine to wrap an outer ring of the upper treatment layer, and completely wrapping the pretreatment marks to form an outer treatment layer, wherein the hot water cooling temperature is controlled at 50 ℃, and the cold water cooling temperature is controlled at 15 ℃;

s5: and (4) extruding and wrapping the flame retardant on the outer treatment layer through an extrusion wrapping process to obtain the durable safe cable.

Wherein, in the process of stranding a plurality of copper wires, at least one copper wire is S-shaped, and at least two copper wires are connected end to end.

Comparative example No. three

A durable safety cable includes an inner core composed of a conductor set; the coating layer comprises the following components in parts by weight: 50 parts of ethylene propylene diene monomer, 40 parts of nitrile rubber, 8 parts of polysulfone membrane, 40 parts of silicon rubber, 20 parts of phenolic resin, 15 parts of polyvinyl chloride resin, 5 parts of chitosan and 15 parts of flame retardant.

Wherein, the wire group is stranded by a plurality of copper wires, and the fire retardant is one or more of antimony trioxide and melamine phosphate.

In a comparative example, a method of making a durable safety cable is also provided, comprising the steps of:

s1: uniformly coating a wire drawing liquid on the surface of a copper bar, drawing the copper bar into a copper wire with the thickness of 1.25mm by using a wire drawing machine, and simultaneously carrying out annealing treatment;

s2: before stranding, polishing each copper wire by using a polisher, stranding a plurality of copper wires to obtain a wire group to obtain an inner core, and then penetrating the inner core through a high-frequency coil for heating, wherein the heating temperature of the high-frequency coil is 160 ℃;

s3: adding ethylene propylene diene monomer, nitrile rubber and silicone rubber into a rubber mixing mill, controlling the roll temperature to be 50 ℃, carrying out pressure refining for 15min, then introducing the materials into a plastic extruding machine, adding a polysulfone film, controlling the temperature to be 100 ℃, carrying out extrusion coating on the upper layer on the outer side of an inner core, respectively carrying out hot water cooling and cold water cooling, and carrying out air cooling blow-drying to form an inner treatment layer, controlling the hot water cooling temperature to be 50 ℃, and controlling the cold water cooling temperature to be 15 ℃;

s4: adding phenolic resin into an extruding machine, crushing and adding chitosan after extruding, and then extruding polyvinyl chloride resin by using the extruding machine to wrap the outer ring of the upper inner treatment layer to form an outer treatment layer;

s5: and (4) extruding and wrapping the flame retardant on the outer treatment layer through an extrusion wrapping process to obtain the durable safe cable.

Wherein, in the process of stranding a plurality of copper wires, at least one copper wire is S-shaped, and at least two copper wires are connected end to end.

Comparative example No. four

A durable safety cable includes an inner core composed of a conductor set; the coating layer comprises the following components in parts by weight: 50 parts of ethylene propylene diene monomer, 40 parts of nitrile rubber, 40 parts of silicone rubber, 20 parts of phenolic resin, 15 parts of polyvinyl chloride resin and 15 parts of flame retardant.

Wherein, the wire group is stranded by a plurality of copper wires, and the fire retardant is one or more of antimony trioxide and melamine phosphate.

In a comparative example, a method of making a durable safety cable is also provided, comprising the steps of:

s1: uniformly coating a wire drawing liquid on the surface of a copper bar, drawing the copper bar into a copper wire with the thickness of 1.25mm by using a wire drawing machine, and simultaneously carrying out annealing treatment;

s2: before stranding, polishing each copper wire by using a polisher, stranding a plurality of copper wires to obtain a wire group to obtain an inner core, and then penetrating the inner core through a high-frequency coil for heating, wherein the heating temperature of the high-frequency coil is 160 ℃;

s3: adding ethylene propylene diene monomer, nitrile rubber and silicone rubber into a rubber mixing mill, controlling the roll temperature to be 50 ℃, carrying out pressure mixing for 15min, then introducing the materials into a plastic extruding machine, carrying out extrusion coating on the upper layer on the outer side of an inner core, respectively carrying out hot water cooling and cold water cooling, and carrying out air cooling blow-drying to form an inner treatment layer, wherein the hot water cooling temperature is controlled to be 50 ℃, and the cold water cooling temperature is controlled to be 15 ℃;

s4: adding phenolic resin and polyvinyl chloride resin into an extruding machine, and extruding an outer ring of the upper inner treatment layer to form an outer treatment layer;

s5: and (4) extruding and wrapping the flame retardant on the outer treatment layer through an extrusion wrapping process to obtain the durable safe cable.

Wherein, in the process of stranding a plurality of copper wires, at least one copper wire is S-shaped, and at least two copper wires are connected end to end.

The cables prepared in the above examples one to four and comparative examples one to four were tested, and the results are shown in the following table 1:

TABLE 1

Wherein, the tensile strength change rate and the elongation at break refer to the change rate before and after the salt spray test; the impact resistance of the cable is the time that the cable is not broken down under 4.5KV under an alternating current withstand voltage test.

As can be clearly seen from table 1, in the first to fourth examples, the tensile strength change rate and the elongation at break of the finally produced cable before and after the salt spray test are both much less than ± 25%, and the cable can be maintained without breakdown for a long time under the ac withstand voltage test;

in the fourth example and the first comparative example which are all the same under other conditions, the polysulfone membrane is not used in the treatment process of the in-process treatment, so that the tensile strength change rate of the obtained cable before and after the salt spray test is more than + 25%, and the breakdown resistance of the cable is slightly reduced under the alternating-current withstand voltage test;

in the second comparative example, chitosan was not used as the intermediate layer between the two resins in the treatment process of the outer treatment layer, so that the elongation at break of the finally obtained cable before and after the salt spray test was more than-25%, and the breakdown resistance of the cable was slightly reduced in the ac withstand voltage test;

in the third comparative example, no pretreatment trace is set in the treatment process of the outer treatment layer, the breakdown resistance of the finally obtained cable is greatly reduced under the alternating-current withstand voltage test, and the tensile strength change rate and the elongation at break before and after the salt spray test are not greatly influenced;

in the fourth comparative example, the polysulfone film was not used in the treatment process of the inner treatment, the chitosan was not used as the intermediate layer between the two resins in the treatment process of the outer treatment layer, and the pretreatment traces were not provided in the treatment process of the outer treatment layer, so that the tensile strength change rate and the elongation at break of the finally obtained cable before and after the salt spray test were significantly increased, both of which were more than ± 25%, and the cable maintainable time was greatly reduced in the ac withstand voltage test.

In conclusion, the cable is prepared and produced by splitting the cable into the inner core and the coating layer, when the coating layer is used for ethylene propylene diene monomer, nitrile butadiene rubber and silicon rubber, the polysulfone film is arranged in the coating layer, so that the three are melted alternately after a rubber mixing machine, the forming state of the three is better, and the hydrocarbon chain link in the polysulfone film also improves the tensile strength of the finally obtained cable and further improves the elongation at break of the cable.

After the inner treatment layer is obtained by using a plurality of rubbers, the inner treatment layer is further coated by using phenolic resin and polyvinyl chloride resin, and chitosan is arranged between the phenolic resin and the polyvinyl chloride resin, so that the forming of the outer treatment layer is more stable, and the intermediate layer formed by the chitosan is tightly embedded on the basis of the outer treatment layer formed by the resins, so that the finally obtained cable has better performance in an alternating current withstand voltage test

In addition, when the inner core is processed, the shape of the lead group is limited, the stability of the inner core is stronger, the inner processing layer is provided with the preprocessing traces, the outer processing layer is further coated more stably and tightly, and the quality of the finally obtained cable finished product is improved.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.