Low-voltage cable with good flame retardance and preparation method thereof

Abstract

The invention provides a low-voltage cable with good flame retardance and a preparation method thereof, and relates to the technical field of cables, the low-voltage cable comprises a conductive wire core, an insulating layer, a flame-retardant layer and an outer sheath, the conductive wire core, the insulating layer, the flame-retardant layer and the outer sheath are sequentially arranged from inside to outside, the periphery of the conductive wire core is coated with the insulating layer, the periphery of the flame-retardant layer is coated with the outer sheath, and the flame-retardant layer is coated with the outer sheath. The flame-retardant layer comprises a fireproof material layer, a first flame-retardant material layer and a second flame-retardant material layer, the first flame-retardant material layer is located between the fireproof material layer and the insulating layer, and the second flame-retardant material layer is located between the fireproof material layer and the outer sheath. According to the low-voltage cable, the flame-retardant layer is arranged between the outer sheath and the insulating layer, and the flame-retardant layer is flame-retardant through the first flame-retardant material layer, the fireproof material layer and the second flame-retardant material layer, so that the flame-retardant effect of the low-voltage cable is improved, fire can be restrained in a local range, fire diffusion is avoided, the damage degree of the fire is reduced, and the service life of the low-voltage cable is prolonged. And the loss caused by fire diffusion is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of cables, and in particular to a low-voltage cable with good flame retardancy and a preparation method thereof. Background Art

[0002] Cable is a conductor covered with an insulating layer, a protective layer, a shielding layer, etc., used to transmit power or signal current or signal voltage. Cables can be divided into high-voltage cables and low-voltage cables according to voltage. Low-voltage cables have the characteristics of reliable operation, no need to erect poles, no ground occupation, no obstruction of appearance, and less affected by the outside world, so they are widely used in low-voltage power distribution systems.

[0003] A Chinese patent with authorization announcement number CN117877793B discloses an environmentally friendly PP insulated low-voltage cable, which includes a conductor, an insulating layer and a protective sleeve arranged in sequence; the material of the insulating layer is plastic and has been cooled, and the thickness of the insulating layer is greater than 0.6 mm; the protective sleeve is coated on the outer periphery of the insulating layer, and the thickness of the protective sleeve is greater than the thickness of the insulating layer; the cable is produced by the following production process: first annealing the conductor, then extruding the insulating layer on the outer periphery of the conductor through an extruder, then extruding the protective sleeve on the outer periphery of the insulating layer through an extruder, and then cooling through a cooling module, and cooling quality detection and control are performed through a cable detection system. The above method can improve the quality of the cable.

[0004] However, when an electrical fault such as a short circuit occurs in the cable, the above-mentioned low-voltage cable lacks flame retardant materials and has a poor flame retardant effect, which can easily cause the fire to spread and cause greater losses. Summary of the invention

[0005] The invention provides a low-voltage cable with good flame retardancy and a preparation method thereof, which are used to solve the technical problem that the current low-voltage cable has poor flame retardancy and is easy to cause fire to spread.

[0006] To solve the above technical problems, the present invention discloses a low-voltage cable with good flame retardancy, comprising: a conductive core, an insulating layer, a flame retardant layer, and an outer sheath, wherein the conductive core, the insulating layer, the flame retardant layer, and the outer sheath are arranged in sequence from the inside to the outside, the insulating layer is coated on the outer periphery of the conductive core, the outer sheath is coated on the outer periphery of the flame retardant layer, the flame retardant layer comprises a fire-retardant material layer, a first flame retardant material layer, and a second flame retardant material layer, the first flame retardant material layer is located between the fire-retardant material layer and the insulating layer, and the second flame retardant material layer is located between the fire-retardant material layer and the outer sheath.

[0007] Also included is a method for preparing a low-voltage cable with good flame retardancy, which is used to prepare the above-mentioned low-voltage cable with good flame retardancy, comprising the following steps:

[0008] Step 1: Prepare the conductive wire core;

[0009] Step 2: Extruding an insulating material onto the outside of the conductive wire core to obtain an insulating layer;

[0010] Step 3: Take a fireproof material layer, spray a first flame retardant material on one side of the fireproof material layer to obtain a first flame retardant material layer, spray a second flame retardant material on the other side of the fireproof material layer to obtain a second flame retardant material layer, and wrap the fireproof material layer with the first flame retardant material layer and the second flame retardant material layer around the outer surface of the insulating layer to obtain a flame retardant layer;

[0011] Step 4: Extrude the outer sheath material onto the outside of the flame retardant layer to obtain the outer sheath, and the low-voltage cable is completed.

[0012] Preferably, the conductor core is a copper core.

[0013] Preferably, the fireproof material layer is made of fireproof webbing.

[0014] Preferably, in step 3, a spraying device is used to spray the first flame retardant material and the second flame retardant material on the outside of the fireproof material layer.

[0015] Preferably, the spraying device includes a spray box, which has a spray inlet and a spray outlet at the upper positions on the left and right sides of the spray box, one end of the fireproof material layer passes through the spray inlet and the spray outlet in sequence and extends to the outside of the spray box, the fireproof material layer is vertically arranged, and the spray components are symmetrically arranged on the front and back sides of the fireproof material layer. The spray component includes a spray pipe, an infusion pump is arranged at the upper position of the spray pipe, the spray pipe is vertically arranged, and a plurality of spray ports are arranged at equal intervals on one side of the spray pipe close to the fireproof material layer. A spray nozzle is arranged at the spray port, and the output end of the spray nozzle faces the fireproof material layer. The upper end of the spray pipe extends to the outside of the spray box and is connected to a liquid storage tank. Two liquid storage tanks are provided, one of which stores a first flame retardant material, and the other stores a second flame retardant material.

[0016] Preferably, a partition is provided in the spray box, which divides the spray box into a spray chamber and a drying chamber. The spray assembly is located in the spray chamber. A through hole compatible with the fireproof material layer is provided in the partition, and the through hole is in the shape of a long strip.

[0017] Preferably, two drying tubes are arranged in the drying chamber, and the two drying tubes are symmetrically arranged on the front and rear sides of the fireproof material layer. One end of the drying tube extends to the outside of the spray box and is connected to the dryer. Several drying ports are arranged on the side of the drying tube close to the fireproof material layer, and a drying nozzle is arranged at the drying port.

[0018] Preferably, a guide plate is horizontally arranged in the spray chamber, the guide plate is horizontally arranged, one end of the guide plate is connected to the partition plate, the other end of the guide plate is connected to the left inner wall of the spray box, a guide groove is provided on the upper surface of the guide plate, the lower end of the fireproof material layer is slidingly connected to the inner wall of the guide groove, a support plate is arranged on the lower surface of the guide plate, the lower end of the support plate is connected to the bottom inner wall of the spray box, one side of the support plate is connected to the left inner wall of the spray box, and the other side of the support plate is connected to the side wall of the partition plate.

[0019] Preferably, liquid outlet holes are provided on the front and rear sides of the guide plate, one end of the liquid outlet hole is connected to the guide groove, and the other end of the liquid outlet hole is connected to the inside of the spraying chamber.

[0020] The technical solution of the present invention has the following advantages: The present invention provides a low-voltage cable with good flame retardancy and a preparation method thereof, which relates to the field of cable technology. The low-voltage cable comprises a conductive core, an insulating layer, a flame retardant layer, and an outer sheath. The conductive core, the insulating layer, the flame retardant layer, and the outer sheath are arranged in sequence from the inside to the outside. The insulating layer is coated on the outer periphery of the conductive core, and the outer sheath is coated on the outer periphery of the flame retardant layer. The flame retardant layer comprises a fire retardant material layer, a first flame retardant material layer, and a second flame retardant material layer. The first flame retardant material layer is located between the fire retardant material layer and the insulating layer, and the second flame retardant material layer is located between the fire retardant material layer and the outer sheath. In the present invention, a flame retardant layer is arranged between the outer sheath and the insulating layer. The flame retardant layer is flame retardant by the first flame retardant material layer, the fire retardant material layer, and the second flame retardant material layer, thereby improving the flame retardant effect of the low-voltage cable, being able to contain the fire in a local area, and avoiding the spread of the fire, thereby reducing the degree of damage caused by the fire and reducing the losses caused by the spread of the fire.

[0021] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the devices particularly pointed out in the written description and the drawings of the description.

[0022] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the overall structure of a low-voltage cable with good flame retardancy according to the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of a spraying device in a method for preparing a low-voltage cable with good flame retardancy according to the present invention;

[0026] Figure 3 It is a schematic diagram of the internal structure of the spray box in the present invention;

[0027] Figure 4 For the present invention Figure 3 The local structure section view at AA in the middle;

[0028] Figure 5 For the present invention Figure 4 A magnified view of the structure at B in the middle;

[0029] Figure 6 Schematic diagram of the internal structure of the mixing tube in the present invention;

[0030] Figure 7 For the present invention Figure 6 A magnified view of the structure at C in the middle;

[0031] Figure 8 It is a schematic diagram of the mixing mechanism in the present invention.

[0032] In the figure: 1, conductive core; 2, insulating layer; 3, flame retardant layer; 301, fireproof material layer; 302, first flame retardant material layer; 303, second flame retardant material layer; 4, outer sheath; 5, spray box; 6, spray pipe; 7, spray nozzle; 8, liquid storage tank; 9, partition; 10, through hole; 11, drying pipe; 12, drying machine; 13, drying nozzle; 14, guide plate; 15, guide groove; 16, support plate; 17, liquid outlet; 1 8. Mounting plate; 19. First liquid extraction pipe; 20. Second liquid extraction pipe; 21. First liquid extraction pump; 22. Second liquid extraction pump; 23. Mixing pipe; 24. Liquid discharge hole; 25. Connecting pipe; 26. Nozzle; 27. Diverter block; 28. Diverter channel; 29. ​​Driving block; 30. Spiral driving groove; 31. Rotating plate; 32. Connecting block; 33. Connecting hole; 34. Liquid discharge channel; 35. Connecting rod; 36. Turntable; 37. Agitating blade. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0034] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] Example 1

[0036] The embodiment of the present invention provides a low-voltage cable with good flame retardancy, such as Figure 1As shown, it includes: a conductive core 1, an insulating layer 2, a flame retardant layer 3, and an outer sheath 4. The conductive core 1, the insulating layer 2, the flame retardant layer 3, and the outer sheath 4 are arranged in sequence from the inside to the outside. The insulating layer 2 is coated on the outer periphery of the conductive core 1, and the outer sheath 4 is coated on the outer periphery of the flame retardant layer 3. The flame retardant layer 3 includes a fire-retardant material layer 301, a first flame retardant material layer 302, and a second flame retardant material layer 303. The first flame retardant material layer 302 is located between the fire-retardant material layer 301 and the insulating layer 2, and the second flame retardant material layer 303 is located between the fire-retardant material layer 301 and the outer sheath 4.

[0037] The working principle and beneficial effects of the above technical solution are as follows: the low-voltage cable comprises a conductive core 1, an insulating layer 2, a flame retardant layer 3, and an outer sheath 4, which are arranged in sequence from the inside to the outside. The flame retardant layer 3 is arranged between the outer sheath 4 and the insulating layer 2. The flame retardant layer 3 comprises a fire-retardant material layer 301, a first flame retardant material layer 302, and a second flame retardant material layer 303. The fire-retardant material layer 301 is made of fire-retardant webbing, and the first flame retardant material layer 302 is made of a phosphorus-based flame retardant sprayed on one side of the fire-retardant material layer 301. The phosphorus-based flame retardant can form a protective layer by promoting the carbonization of the material, thereby isolating oxygen and heat to achieve a flame retardant effect. The second flame retardant material layer 303 is made of a nitrogen-based flame retardant sprayed on the other side of the fire-retardant material layer 301. The flame retardant mainly dilutes the combustible gas by releasing non-combustible gas, reduces the oxygen concentration in the combustion area, and thus achieves a flame retardant effect. The fire-retardant material layer 301, the first flame retardant material layer 302 and the second flame retardant material layer 303 all have flame retardant effects. By arranging the first flame retardant material layer 302 and the second flame retardant material layer 303, the flame retardant layer 3 combines the advantages of two flame retardants and can provide more comprehensive and efficient flame retardant performance. The second flame retardant material layer 303, the fire-retardant material layer 301 and the first flame retardant material layer 302 are flame-retarded in sequence, thereby improving the flame retardant effect of the low-voltage cable, being able to contain the fire in a local area and avoid the spread of the fire, thereby reducing the degree of damage caused by the fire and reducing the losses caused by the spread of the fire.

[0038] Example 2

[0039] On the basis of the above-mentioned embodiment 1, Figure 1-Figure 8 As shown, the present application also discloses a method for preparing a low-voltage cable with good flame retardancy, which is used to prepare the above-mentioned low-voltage cable with good flame retardancy, comprising the following steps:

[0040] Step 1: Prepare the conductive core 1;

[0041] Step 2: Extruding an insulating material onto the outside of the conductive core 1 to obtain an insulating layer 2;

[0042] Step 3: Take a fireproof material layer 301, spray a first flame retardant material on one side of the fireproof material layer 301 to obtain a first flame retardant material layer 302, spray a second flame retardant material on the other side of the fireproof material layer 301 to obtain a second flame retardant material layer 303, and wrap the fireproof material layer 301 with the first flame retardant material layer 302 and the second flame retardant material layer 303 around the outer surface of the insulating layer 2 to obtain a flame retardant layer 3;

[0043] Step 4: Extruding the outer sheath 4 material onto the outside of the flame retardant layer 3 to obtain the outer sheath 4, and the low-voltage cable is completed;

[0044] Among them, the wire core is a copper battery core;

[0045] The fireproof material layer 301 is made of fireproof webbing.

[0046] The working principle and beneficial effects of the above technical solution are as follows: first prepare a conductive core 1, which is a copper core; then extrude an insulating material onto the outside of the conductive core 1 to obtain an insulating layer 2, and the insulating material can be selected from commonly used insulating materials for existing cables; then take a fireproof material layer 301, and the fireproof material layer 301 can be selected from a fireproof webbing, and spray a first flame retardant material on one side of the fireproof material layer 301 to obtain a first flame retardant material layer 302, and the first flame retardant material layer 302 uses a phosphorus-based flame retardant, which can form a protective layer by promoting the carbonization of the material, thereby isolating oxygen and heat to achieve flame retardancy. The second flame retardant material layer 303 is sprayed on the other side of the fire retardant material layer 301 to obtain the second flame retardant material layer 303. The second flame retardant material layer 303 adopts a nitrogen flame retardant. The nitrogen flame retardant mainly dilutes the combustible gas by releasing non-combustible gas to reduce the oxygen concentration in the combustion area, thereby achieving a flame retardant effect. The fire retardant material layer 301 with the first flame retardant material layer 302 and the second flame retardant material layer 303 is then wrapped around the outer surface of the insulating layer 2 to obtain a flame retardant layer 3. Finally, the outer sheath 4 material is extruded around the outside of the flame retardant layer 3 to obtain the outer sheath 4. After cooling, it is cut as needed to obtain a low-voltage cable. The fire-retardant material layer 301, the first flame-retardant material layer 302 and the second flame-retardant material layer 303 of the above-mentioned low-voltage cable all have flame-retardant effects. By sequentially flame-retarding the second flame-retardant material layer 303, the fire-retardant material layer 301 and the first flame-retardant material layer 302, the flame-retardant effect of the low-voltage cable is improved, and the fire can be contained in a local area to avoid the spread of the fire, thereby reducing the degree of damage caused by the fire and reducing the losses caused by the spread of the fire.

[0047] Example 3

[0048] On the basis of Example 2, Figure 2-Figure 5 As shown, in step 3, a spraying device is used to spray the first flame retardant material and the second flame retardant material on the outside of the fireproof material layer 301;

[0049] The spraying device includes a spray box 5, which has a spray inlet and a spray outlet at the upper positions on the left and right sides of the spray box 5, one end of the fireproof material layer 301 passes through the spray inlet and the spray outlet in sequence and extends to the outside of the spray box 5, the fireproof material layer 301 is vertically arranged, and the spray components are symmetrically arranged on the front and back sides of the fireproof material layer 301. The spray component includes a spray pipe 6, an infusion pump is arranged at the upper position of the spray pipe 6, the spray pipe 6 is vertically arranged, and a plurality of spray ports are evenly spaced on one side of the spray pipe 6 close to the fireproof material layer 301. A spray nozzle 7 is arranged at the spray port, and the output end of the spray nozzle 7 faces the fireproof material layer 301. The upper end of the spray pipe 6 extends to the outside of the spray box 5 and is connected to a liquid storage tank 8. Two liquid storage tanks 8 are arranged, one of which stores a first flame retardant material, and the other stores a second flame retardant material.

[0050] The working principle and beneficial effects of the above technical solution are as follows: a first flame retardant material is stored in a liquid storage tank 8, and the first flame retardant material is a phosphorus-based flame retardant; a second flame retardant material is stored in another liquid storage tank 8, and the second flame retardant material is a nitrogen-based flame retardant; both ends of the fireproof material layer 301 pass through the spray box 5, and the fireproof material layer 301 is arranged vertically, one end of the fireproof material layer 301 is wound on a winding roller, and the other end of the fireproof material layer 301 is wound on an unwinding roller. When preparing the first flame retardant material layer 302 and the second flame retardant material layer 303, the winding roller and the unwinding roller are started, and the fireproof material layer 301 starts to be sprayed in the spray box 5. The first flame retardant material layer 302 and the second flame retardant material layer 303 are transported in the spray tube 6, and the first flame retardant material layer 302 and the second flame retardant material layer 303 are evenly sprayed on the other side of the fire retardant material layer 301 through the spray nozzle 7. The first flame retardant material layer 302 and the second flame retardant material layer 303 are prepared at the same time, and the preparation efficiency of the flame retardant layer 3 is improved. The first flame retardant material layer 302 and the second flame retardant material layer 303 can produce a synergistic effect during the combustion process, and jointly improve the flame retardant properties of the fire retardant material layer 301.

[0051] Example 4

[0052] On the basis of Example 3, Figure 3 As shown, a partition 9 is provided in the spray box 5, and the partition 9 divides the spray box 5 into a spray chamber and a drying chamber. The spray assembly is located in the spray chamber, and a through hole 10 adapted to the fireproof material layer 301 is provided in the partition 9, and the through hole 10 is in a long strip shape;

[0053] Two drying tubes 11 are arranged in the drying chamber, and the two drying tubes 11 are symmetrically arranged on the front and back sides of the fireproof material layer 301. One end of the drying tube 11 extends to the outside of the spray box 5 and is connected to the dryer 12. Several drying ports are arranged on the side of the drying tube 11 close to the fireproof material layer 301, and a drying nozzle 13 is arranged at the drying port.

[0054] The working principle and beneficial effects of the above technical scheme are as follows: the partition 9 can divide the spray box 5 into a spray chamber and a drying chamber. The fireproof material layer 301 first enters the spray chamber through the spray inlet. When the first flame retardant material and the second flame retardant material are sprayed on the front and back sides of the fireproof material layer 301 respectively, the fireproof material layer 301 moves to the drying chamber, and the dryer 12 is started. The drying airflow generated by the dryer 12 is distributed to each drying nozzle 13 through the drying pipe 11 and sprayed out from the drying nozzle 13. The drying airflow can dry the first flame retardant material and the second flame retardant material, thereby accelerating the preparation of the first flame retardant material layer 302 and the second flame retardant material layer 303, and further improving the preparation efficiency of the flame retardant layer 3.

[0055] Example 5

[0056] On the basis of Example 4, Figure 3-Figure 5 As shown, a guide plate 14 is horizontally arranged in the spray chamber, the guide plate 14 is horizontally arranged, one end of the guide plate 14 is connected to the partition plate 9, the other end of the guide plate 14 is connected to the left inner wall of the spray box 5, a guide groove 15 is arranged on the upper surface of the guide plate 14, the lower end of the fireproof material layer 301 is slidably connected to the inner wall of the guide groove 15, a support plate 16 is arranged on the lower surface of the guide plate 14, the lower end of the support plate 16 is connected to the bottom inner wall of the spray box 5, one side of the support plate 16 is connected to the left inner wall of the spray box 5, and the other side of the support plate 16 is connected to the side wall of the partition plate 9;

[0057] Liquid outlet holes 17 are provided at both the front and rear sides of the guide plate 14 . One end of the liquid outlet hole 17 is communicated with the guide groove 15 , and the other end of the liquid outlet hole 17 is communicated with the interior of the spraying chamber.

[0058] The working principle and beneficial effects of the above technical solution are as follows: when the fireproof material layer 301 moves in the spray box 5, the guide groove 15 in the guide plate 14 can guide and limit the bottom of the fireproof material layer 301, so as to prevent the fireproof material layer 301 from shaking violently during spraying, thereby improving the stability of the fireproof material layer 301, thereby ensuring the uniformity of spraying of the first flame retardant material and the second flame retardant material, and improving the preparation quality of the flame retardant layer 3. The support plate 16 can provide support for the guide plate 14, ensuring the stability of the guide plate 14. At the same time, the support plate 16 separates the bottom space of the spray chamber into front and back. During the spraying process, since the fireproof material layer 301 is vertically arranged, the excess first flame retardant material and the second flame retardant material will flow downward along the outside of the fireproof material layer 301, and part of the first flame retardant material In the process of flowing downward along the fireproof material layer 301, the first flame retardant material and the second flame retardant material can flow into the gap inside the fireproof material layer 301, so that the flame retardant can fully penetrate into the fireproof material layer 301, thereby improving the spraying effect, and further improving the flame retardant effect of the flame retardant layer 3. Another part of the first flame retardant material and the second flame retardant material will be separated from the fireproof material layer 301 and fall into the bottom of the spraying chamber. Under the separation of the support plate 16, the first flame retardant material and the second flame retardant material will fall into different recovery spaces respectively, and only a small amount of the first flame retardant material and the second flame retardant material will mix and flow out through the liquid outlet 17, thereby avoiding the waste of the first flame retardant material and the second flame retardant material. In addition, the first flame retardant material and the second flame retardant material on the surface of the fireproof material layer 301 are reduced, which is convenient for subsequent drying and improves the drying efficiency.

[0059] Example 6

[0060] On the basis of Example 5, Figure 3-Figure 8As shown, a secondary spraying mechanism is symmetrically arranged on the front and rear sides of the fireproof material layer 301, and the secondary spraying mechanism is located between the spraying tube 6 and the partition 9. The secondary spraying mechanism includes a mounting plate 18, and one side of the mounting plate 18 is connected to the inner wall of the spray box 5. Two mounting holes are arranged in the mounting plate 18, and a first liquid pumping tube 19 is arranged in one of the mounting holes, and a second liquid pumping tube 20 is arranged in the other mounting hole. A first liquid pumping pump 21 is arranged on the first liquid pumping tube 19, and a second liquid pumping pump 22 is arranged on the second liquid pumping tube 20. A horizontal section is arranged on the upper end of the first liquid pumping tube 19, and the horizontal section of the first liquid pumping tube 19 extends into the mixing tube 23, and the horizontal section is evenly opened in a circumferential direction. A dry drainage hole 24 is connected to the interior of the first liquid extraction pipe 19, the upper end of the second liquid extraction pipe 20 is connected to the bottom wall of the mixing tube 23, a connecting pipe 25 is arranged at one end of the mixing tube 23 close to the fireproof material layer 301, a nozzle 26 is arranged at one end of the connecting pipe 25 close to the fireproof material layer 301, a plurality of liquid spraying holes are arranged on the nozzle 26, a horizontal section close to one end of the nozzle 26 is arranged as a closed end, a diverter block 27 is arranged between the horizontal section and the nozzle 26, the cross-section of the diverter block 27 is diamond-shaped, a diverter channel 28 is arranged on the outer wall of the diverter block 27, one end of the diverter channel 28 is connected to the interior of the nozzle 26, and the other end of the diverter channel 28 is connected to the interior of the mixing tube 23.

[0061] The working principle and beneficial effects of the above technical solution are as follows: the dripping first flame retardant material and the second flame retardant material will accumulate at the bottom of the spray chamber to form a recovery liquid. In order to further improve the preparation effect of the first flame retardant material layer 302 and the second flame retardant material layer 303, a secondary spraying mechanism is also arranged on the front and rear sides of the fireproof material layer 301. During spraying, the first liquid pump 21 and the second liquid pump 22 are started. The first liquid pump 21 can draw the recovery liquid into the first liquid pumping pipe 19, and then flow out to the inside of the mixing pipe 23 through the drainage hole 24 of the horizontal section. The second liquid pump 22 draws the recovery liquid into the second liquid pumping pipe 20, and then enters the second liquid pumping pipe 20 through the upper end. The recycled liquid enters the mixing tube 23, and is mixed in the mixing tube 23 to form a mixed liquid, which flows to the nozzle 26 through the diverter channel 28 on the outer wall of the diverter block 27, and is sprayed onto the surface of the fireproof material layer 301 through the spray hole of the nozzle 26. The aperture of the diverter channel 28 is much smaller than the inner diameter of the mixing tube 23, which can accelerate the flow rate of the mixed liquid, so that the mixed liquid can be quickly sprayed out from the nozzle 26, thereby expanding the spraying range. The nozzles 26 on the front and rear sides can spray the corresponding mixed liquid at the same time, and spray the fireproof material layer 301 for the second time, which further improves the spraying effect and makes the fireproof material layer 301 absorb the first flame retardant material and the second flame retardant material more fully.

[0062] Example 7

[0063] On the basis of Example 6, Figure 6-Figure 8As shown, a driving block 29 is arranged outside the horizontal section of the first liquid pumping tube 19, and a spiral driving groove 30 is arranged on the outer wall of the driving block 29. A mixing mechanism is arranged between the driving block 29 and the diverter block 27, and the mixing mechanism includes a rotating plate 31. Two adjacent rotating plates 31 are connected by a connecting block 32. The rotating plate 31 is in a fan ring shape. The inner wall of the rotating plate 31 is rotatably connected to the outer wall of the mixing tube 23. A connecting hole 33 is arranged in the rotating plate 31, and the connecting hole 33 is connected to the drainage hole 24. A drainage channel 34 is also arranged in the rotating plate 31. The diameter of the drainage channel 34 is smaller than the diameter of the connecting hole 33. One end of the drainage channel 34 is connected to the connecting hole 33, and the other end of the drainage channel 34 is connected to the inside of the mixing tube 23. The two ends of the rotating plate 31 are connected by a connecting rod 35. The connecting rod 35 is arc-shaped. A plurality of turntables 36 are rotatably arranged on the connecting rod 35, and a plurality of stirring blades 37 are obliquely arranged on the outer wall of the turntable 36.

[0064] The working principle and beneficial effects of the above technical solution are as follows: taking the collection of the first flame retardant material on the front side of the support plate 16 as an example, inevitably, a small amount of the second flame retardant material will also flow to the front side of the support plate 16 through the liquid outlet 17 and mix with the first flame retardant material. Therefore, when selecting the first flame retardant material and the second flame retardant material, it is necessary to ensure that the two have good compatibility to avoid adverse reactions or stratification. When the second flame retardant material falls into the first flame retardant material to form a recovered liquid, as the recovered liquid flows out of the drainage hole 24, part of the recovered liquid enters the connecting hole 33 through the drainage hole 24, and then is sprayed into the mixing tube 23 through the drainage channel 34. As the recovered liquid is quickly sprayed out, it can be quickly mixed with the recovered liquid in the mixing tube 23 to improve the mixing effect of the first flame retardant material and the second flame retardant material. When another part of the recovered liquid is discharged through the drainage pipe, it can push the stirring blade 37 to rotate, and the stirring blade 37 drives the turntable 36 to rotate, and the turntable 36 drives The multiple stirring blades 37 on the movable outer wall rotate to accelerate the stirring of the recovery liquid in the mixing tube 23, thereby improving the mixing efficiency of the recovery liquid. In addition, when the recovery liquid flowing out through the second liquid extraction pipe 20 is discharged through the spiral driving groove 30 of the driving block 29, it can make the recovery liquid spirally flow between the driving block 29 and the diverter block 27, and drive the rotating plate 31 to rotate on the outer wall of the mixing tube 23, thereby further improving the mixing efficiency of the recovery liquid between the driving block 29 and the diverter block 27. The mixed mixed liquid is quickly sprayed from the nozzle 26 to the fireproof material layer 301, and the mixed liquid is in full contact with the fireproof material layer 301, so that the first flame retardant material and the second flame retardant material are stably attached to the surface of the fireproof material layer 301, thereby finally improving the flame retardant properties of the flame retardant layer 3, ensuring that the low-voltage cable has excellent flame retardant properties, and being able to contain the fire in a local area when a fire occurs to avoid the spread of the fire, thereby reducing the degree of damage caused by the fire and reducing the losses caused by the spread of the fire.

[0065] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0066] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A low-voltage cable with good flame retardancy, characterized in that: include: The invention relates to a conductive core (1), an insulating layer (2), a flame retardant layer (3), and an outer sheath (4). The conductive core (1), the insulating layer (2), the flame retardant layer (3), and the outer sheath (4) are arranged in sequence from the inside to the outside. The insulating layer (2) is coated on the outer periphery of the conductive core (1), and the outer sheath (4) is coated on the outer periphery of the flame retardant layer (3). The flame retardant layer (3) comprises a fireproof material layer (301), a first flame retardant material layer (302), and a second flame retardant material layer (303). The first flame retardant material layer (302) is located between the fireproof material layer (301) and the insulating layer (2), and the second flame retardant material layer (303) is located between the fireproof material layer (301) and the outer sheath (4).

2. A method for preparing a low-voltage cable with good flame retardancy, used for preparing a low-voltage cable with good flame retardancy as claimed in claim 1, characterized in that: The following steps are involved: Step 1: Prepare a conductive core (1); Step 2: Extruding an insulating material onto the outside of the conductive wire core (1) to obtain an insulating layer (2); Step 3: Take a fireproof material layer (301), spray a first flame retardant material on one side of the fireproof material layer (301) to obtain a first flame retardant material layer (302), spray a second flame retardant material on the other side of the fireproof material layer (301) to obtain a second flame retardant material layer (303), and wrap the fireproof material layer (301) with the first flame retardant material layer (302) and the second flame retardant material layer (303) around the outer surface of the insulating layer (2) to obtain a flame retardant layer (3); Step 4: Extruding the outer sheath (4) material onto the outside of the flame retardant layer (3) to obtain the outer sheath (4), and the low-voltage cable is completed.

3. The method for preparing a low-voltage cable with good flame retardancy according to claim 2, characterized in that: The conductor core is a copper core.

4. The method for preparing a low-voltage cable with good flame retardancy according to claim 2, characterized in that: The fireproof material layer (301) is made of fireproof webbing.

5. The method for preparing a low-voltage cable with good flame retardancy according to claim 2, characterized in that: In step 3, a spraying device is used to spray the first flame retardant material and the second flame retardant material on the outside of the fireproof material layer (301).

6. A method for preparing a low-voltage cable with good flame retardancy according to claim 5, characterized in that: The spraying device comprises a spraying box (5), wherein a spraying inlet and a spraying outlet are provided at upper positions on both sides of the spraying box (5), one end of the fireproof material layer (301) passes through the spraying inlet and the spraying outlet in sequence and extends to the outside of the spraying box (5), the fireproof material layer (301) is arranged vertically, and spraying components are symmetrically arranged on the front and rear sides of the fireproof material layer (301), and the spraying components comprise a spraying pipe (6), an infusion pump is arranged at the upper position of the spraying pipe (6), the spraying pipe (6) is arranged vertically, and a plurality of spraying ports are arranged at equal intervals on one side of the spraying pipe (6) close to the fireproof material layer (301), and a spraying nozzle (7) is arranged at the spraying port, and the output end of the spraying nozzle (7) faces the fireproof material layer (301), the upper end of the spraying pipe (6) extends to the outside of the spraying box (5) and is connected to a liquid storage tank (8), and two liquid storage tanks (8) are arranged, wherein one liquid storage tank (8) stores a first flame retardant material, and the other liquid storage tank (8) stores a second flame retardant material.

7. A method for preparing a low-voltage cable with good flame retardancy according to claim 6, characterized in that: A partition (9) is arranged in the spray box (5), and the partition (9) divides the spray box (5) into a spray chamber and a drying chamber. The spray assembly is located in the spray chamber. A through hole (10) adapted to the fireproof material layer (301) is provided in the partition (9), and the through hole (10) is in a long strip shape.

8. The method for preparing a low-voltage cable with good flame retardancy according to claim 7, characterized in that: Two drying tubes (11) are arranged in the drying chamber. The two drying tubes (11) are symmetrically arranged on the front and rear sides of the fireproof material layer (301). One end of the drying tube (11) extends to the outside of the spray box (5) and is connected to the dryer (12). A plurality of drying ports are arranged on the side of the drying tube (11) close to the fireproof material layer (301), and a drying nozzle (13) is arranged at the drying port.

9. The method for preparing a low-voltage cable with good flame retardancy according to claim 7, characterized in that: A guide plate (14) is horizontally arranged in the spray chamber, the guide plate (14) is horizontally arranged, one end of the guide plate (14) is connected to the partition plate (9), the other end of the guide plate (14) is connected to the left inner wall of the spray box (5), a guide groove (15) is arranged on the upper surface of the guide plate (14), the lower end of the fireproof material layer (301) is slidably connected to the inner wall of the guide groove (15), a support plate (16) is arranged on the lower surface of the guide plate (14), the lower end of the support plate (16) is connected to the bottom inner wall of the spray box (5), one side of the support plate (16) is connected to the left inner wall of the spray box (5), and the other side of the support plate (16) is connected to the side wall of the partition plate (9).

10. A method for preparing a low-voltage cable with good flame retardancy according to claim 9, characterized in that: Liquid outlet holes (17) are provided on both the front and rear sides of the guide plate (14), one end of the liquid outlet hole (17) is communicated with the guide groove (15), and the other end of the liquid outlet hole (17) is communicated with the inside of the spraying chamber.

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