High-flame-retardant fire-resistant cable and preparation method thereof

Abstract

The invention relates to the technical field of cable preparation devices, in particular to a high-flame-retardant fire-resistant cable and a preparation method thereof. The device comprises an insulating material preparation device, the insulating material preparation device comprises a workbench, a modification assembly is arranged above the workbench, a discharging assembly is arranged at the top of the modification assembly, a dredging assembly is arranged between the workbench and the modification assembly, and a hot melting assembly is arranged on one side of the workbench; the stirring paddle continuously passes through the top of the wedge-shaped plate during rotation, and during the period, the dredging rod slides downwards in the discharging channel when the wedge-shaped plate is pressed downwards, so that a large block of flame retardant blocked at an inlet of the discharging channel is mashed. After a large flame retardant is smashed into small blocks, if the small blocks directly enter the hot melting cavity along with the plastic raw materials, the situation of uneven mixing still occurs, and therefore after the smashed small blocks of flame retardant fall into the grinding groove, the flame retardant is ground into powder from the small blocks in the process that the grinding teeth pass through the grinding groove.

Description

Technical Field

[0001] The present invention relates to the technical field of cable preparation devices, in particular to a highly flame-retardant and fire-resistant cable and a preparation method thereof. Background Art

[0002] Cables primarily consist of an inner conductor and an outer insulator, with the outer insulator's material composition determining the cable's properties. For example, to produce cables with high flame retardancy and fire resistance, a flame retardant must be added to the plastic raw material during the melt preparation of the cable pellets. However, metal hydroxide-based inorganic flame retardants, such as aluminum hydroxide and magnesium hydroxide, are highly hygroscopic and prone to agglomeration during use. Adding these agglomerated flame retardants to the plastic raw material can lead to uneven mixing and blockage of the feed channel, thus compromising the flame retardancy and fire resistance of the resulting cable insulation material.

[0003] Existing cable preparation devices typically incorporate a dredging mechanism in the material feed channel to break up any clumping flame retardant that becomes clogged. However, existing dredging mechanisms can only break up larger particles into smaller ones. The flame retardant that enters the hot-melt device along with the plastic particles remains in a clumpy state, resulting in uneven mixing after hot-melting, which in turn affects the flame retardancy and fire resistance of the resulting cable insulation material.

[0004] In view of this, we propose a highly flame retardant and fire resistant cable and a preparation method thereof to improve the deficiencies in the existing technology. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a method for preparing highly flame-retardant and fire-resistant cables, which solves the problem that in existing cable preparation devices, a dredging structure is usually set at the material discharge channel to crush the flame retardant agglomerated in the material discharge channel. However, the existing dredging structure can only crush larger particles into smaller particles, that is:

[0006] After small pieces of flame retardant follow the plastic raw materials into the hot melt device for hot melting, the problem of uneven mixing will still occur.

[0007] To achieve the above-mentioned purpose, the preparation method of the highly flame-retardant and fire-resistant cable comprises the following steps:

[0008] S1. Conductor preparation: Anneal the copper / aluminum rod (500°C for copper and 200°C for aluminum) to eliminate processing stress and improve flexibility. Then, twist the single wires into bundles according to cable specifications, such as a 7-strand structure. The twisting pitch must be uniform to avoid stress concentration.

[0009] S2. Preparation of flame retardant and fire resistant materials: adding flame retardant and plastic raw materials into an insulation material preparation device, mixing the flame retardant and plastic raw materials, and then melt-extruding to obtain a cable insulation material with high flame retardant and fire resistant properties;

[0010] S3, cross-linking treatment: after extrusion, the cross-linking treatment is carried out through a steam vulcanization tube at a temperature of 180-220°C, a pressure of 1.8-2.2 MPa, and a time of 18-22 minutes to form a three-dimensional network structure;

[0011] S4, cabling process;

[0012] S4.1. Insulated wire core treatment: Use a mechanical straightening machine to eliminate wire core bending with a tension of 9-11N to ensure roundness;

[0013] S4.2, Filling and Binding: First fill the gaps with hemp rope to improve structural stability, then spirally wrap fiberglass tape to prevent loosening;

[0014] S5. Sheath extrusion: Set the sheath material extruder parameters to 170-190℃ for PVC sheath material. After extrusion, the sheath material is first passed through a cold water tank at 18-22℃ for rapid shaping, and then passed through a warm water tank at 40-60℃ to eliminate internal stress and avoid cracking of the sheath.

[0015] S6. Aging and shaping: The obtained cable is placed in an aging box with a temperature of 80-100°C for 48-52 hours to eliminate internal stress and stabilize the structure. Finally, the cable is packaged on an ironwood reel, and the outer layer of the cable is wrapped with moisture-proof paper. Both ends are sealed to prevent moisture, and a highly flame-retardant and fire-resistant cable product is obtained.

[0016] The insulating material preparation device includes a workbench, a modifying component is provided above the workbench, a blanking component is provided on the top of the modifying component, a dredging component is provided between the workbench and the modifying component, a hot melt component is provided on one side of the workbench, the modifying component and the hot melt component are connected through the dredging component, the blanking component is used to store flame retardants, which are inorganic flame retardants of metal hydroxides such as aluminum hydroxide and magnesium hydroxide, and the plastic raw material mixed with the flame retardant enters the hot melt component through the dredging component. The hot melt component is used to heat and melt the plastic raw material, and finally extrude it to obtain a highly flame-retardant and fire-resistant insulating material;

[0017] The modified component includes a stirring piece for stirring plastic raw materials and flame retardants. During the rotation of the stirring piece, the stirring piece moves the bottom of the unloading component to achieve intermittent unloading. At the same time, the stirring piece continuously presses down the top of the dredging component to crush the block flame retardant blocking the top of the dredging component, thereby crushing the large blocks of flame retardant blocking the entrance of the dredging component into small pieces. During the process of the stirring piece passing over the top of the dredging component, the stirring piece can grind the crushed block flame retardant, that is, grind the small pieces of flame retardant into fine powder.

[0018] In the above technical solution, the modification component includes a modification chamber for mixing plastic raw materials and flame retardants. The main shaft is distributed along the axis of the modification chamber and is rotatably connected to the side wall of the modification chamber. The stirring element includes multiple stirring paddles distributed radially along the main shaft. The main shaft is driven by a motor to drive the multiple stirring paddles to rotate to mix the plastic raw materials and flame retardants.

[0019] The top of the modification bin is provided with a mounting seat for installing a blanking component, so that flame retardants can be intermittently added to the plastic raw materials in the modification bin during the stirring of the plastic raw materials, avoiding the application of too much flame retardant to the plastic raw materials at one time. The stirring paddle is provided with a plurality of grinding teeth at the end away from the main shaft. The grinding teeth can further grind small pieces of flame retardant into fine powder in the process of contacting the top of the dredging component, so as to facilitate the full mixing of the flame retardant and the plastic raw materials in the subsequent melting stage.

[0020] In another technical solution, the unloading assembly includes a storage bin fixedly connected to a mounting base, a baffle is slidably connected to the bottom opening of the storage bin, a shift bar is provided on one side of the top of the baffle, and when the stirring paddle is vertically upward, a fixing part is provided at one end of the baffle for preventing the baffle from falling off from the bottom of the storage bin, and the height of the top of the stirring paddle is higher than the height of the bottom of the shift bar.

[0021] The fixing part includes a seal fixedly connected to the baffle, the width of the seal is greater than the width of the baffle, a pair of limit bolts are symmetrically provided on both sides of the storage bin away from each other, the parts of the seal wider than the storage bin at both ends are fixedly connected to guide rods, each of the guide rods is slidably connected to the corresponding limit bolt, the end of the guide rod away from the seal is fixedly connected to the limit cap, and a first spring is sleeved on the periphery of the guide rod between the limit bolt and the limit cap.

[0022] Based on the above scheme, the dredging component includes a feed channel connected to the bottom of the modification bin, and the feed channel is used to feed the plastic raw material with flame retardant mixed on the surface into the hot melt component. A dredging rod is axially provided at the inner axis of the feed channel, and a grinding dredging piece is provided on the top of the dredging rod for blocking the plastic raw material and preventing it from entering the hot melt component too quickly. The inner wall of the feed channel is fixedly connected to a limit plate, and the dredging rod is slidably connected to the limit plate. The width of the limit plate is smaller than the inner diameter of the feed channel, and a second spring is provided between the grinding dredging piece and the limit plate for resetting the grinding dredging piece that slides downward.

[0023] The grinding and dredging member includes a plate body, which includes a flat plate and a wedge-shaped plate. A plurality of grinding grooves are provided on the top of the flat plate and the wedge-shaped plate. During the rotation of the stirring paddle, the grinding teeth first pass through the grinding grooves on the top of the flat plate and then pass through the grinding grooves on the top of the wedge-shaped plate. Since the top height of the wedge-shaped plate is higher than the top height of the flat plate and is an inclined surface, when the abrasive teeth pass through the grinding grooves on the top of the wedge-shaped plate, the wedge-shaped plate is compressed to drive the dredging rod to slide downward.

[0024] In the above scheme, the hot melt component includes a hot melt chamber for melting plastic raw materials and flame retardants. The hot melt chamber is heated by a heating sleeve in the prior art. An auger is axially provided at the axis of the hot melt chamber. The auger is used to provide shear force to evenly mix the plastic raw materials and flame retardants, as well as a driving force to push the molten plastic forward.

[0025] A main rod is provided at the axis of the auger, and the main rod is also driven by a motor. A plurality of extrusion channels are opened at one end of the hot melt cavity away from the workbench.

[0026] A second object of the present invention is to provide a highly flame-retardant and fire-resistant cable, comprising a conductor and an insulating material, wherein the insulating material is prepared by the above-mentioned method for preparing a highly flame-retardant and fire-resistant cable.

[0027] Based on the above description, it can be seen that compared with the prior art, the beneficial effects of the present invention are:

[0028] Multiple stirring paddles continuously pass through the bottom of the baffle, and the far end of the stirring paddle drives the baffle to slide by pushing the dial, thereby exposing the opening of the storage bin. While the baffle is being pushed, the limit cap slides synchronously with the guide rod. After the stirring paddle leaves the dial, the first spring drives the baffle to reset and seal the opening at the bottom of the storage bin, thereby realizing intermittent addition of flame retardant to the storage bin.

[0029] At the same time, the stirring paddle rotates and continuously passes over the top of the wedge plate. During this time, the wedge plate is pressed down, and the dredging rod slides downward within the discharge channel, thereby breaking up large pieces of flame retardant blocking the discharge channel entrance. If the large pieces of flame retardant are broken into small pieces and directly enter the hot melt chamber with the plastic raw material, uneven mixing will still occur. Therefore, the crushed small pieces of flame retardant fall into the grinding trough, where the grinding teeth slide across the grinding trough, grinding the flame retardant from small pieces into powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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:

[0031] Figure 1 It is a three-dimensional diagram of the overall structure of the present invention;

[0032] Figure 2 It is a partially cutaway perspective view of the present invention;

[0033] Figure 3 It is a partially cut-away left side view of the present invention;

[0034] Figure 4 is a cutaway perspective view of the modified component of the present invention;

[0035] Figure 5 It is a cutaway left side view of the modified component of the present invention;

[0036] Figure 6 is a cutaway perspective view of the blanking assembly of the present invention;

[0037] Figure 7 It is a cutaway left side view of the blanking assembly of the present invention;

[0038] Figure 8 is a cutaway perspective view of the dredging assembly of the present invention;

[0039] Figure 9 It is a cutaway left side view of the dredging assembly of the present invention;

[0040] Figure 10 This is a structural perspective view of the dredging grinding piece of the present invention;

[0041] Figure 11 is a cutaway perspective view of the hot melt assembly of the present invention;

[0042] Figure 12 It is a cutaway left side view of the hot melt assembly of the present invention.

[0043] The meaning of each number in the figure is:

[0044] 100. Workbench;

[0045] 200, modification component; 210, modification chamber; 220, main shaft; 230, stirring paddle; 231, abrasive tooth; 240, mounting seat;

[0046] 300, blanking assembly; 310, storage bin; 320, baffle; 330, shift bar; 340, seal; 341, limit bolt; 342, guide rod; 343, limit cap; 344, first spring;

[0047] 400, dredging assembly; 410, feeding channel; 420, dredging rod; 430, grinding dredging piece; 431, plate body; 432, flat plate; 433, wedge plate; 434, grinding groove; 440, limit plate; 450, second spring; 500, hot melt assembly; 510, hot melt chamber; 520, main rod; 530, auger; 540, extrusion channel. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0049] In Example 1, after the small pieces of flame retardant crushed by the dredging device are melted along with the plastic raw materials into the hot melting device, there will still be uneven mixing, which will affect the flame retardant and fire resistant properties of the obtained cable insulation material. Please refer to Figure 1-Figure 3 shown.

[0050] The present invention provides a method for preparing a highly flame-retardant and fire-resistant cable, comprising the following steps:

[0051] S1. Conductor preparation: anneal the copper rod / aluminum rod at 500℃ for copper and 200℃ for aluminum to eliminate processing stress and improve flexibility. Then, twist the single wires into bundles according to cable specifications, such as 7-strand structure. The twist pitch must be uniform to avoid stress concentration.

[0052] S2. Preparation of flame retardant and fire resistant materials: adding flame retardant and plastic raw materials into an insulation material preparation device, mixing the flame retardant and plastic raw materials, and then melt-extruding to obtain a cable insulation material with high flame retardant and fire resistant properties;

[0053] S3, cross-linking treatment: after extrusion, the product passes through a steam vulcanization tube at a temperature of 200°C and a pressure of 2 MPa for 20 minutes to form a three-dimensional network structure;

[0054] S4, cabling process;

[0055] S4.1. Insulated wire core treatment: Use a mechanical straightening machine to eliminate wire core bending with a tension of 10N to ensure roundness;

[0056] S4.2, Filling and Binding: First fill the gaps with hemp rope to improve structural stability, then spirally wrap fiberglass tape to prevent loosening;

[0057] S5. Sheath extrusion: Set the sheath material extruder parameters to PVC sheath material at 180℃. After the sheath material is extruded, it is first passed through a cold water tank at 20℃ for rapid shaping, and then passed through a warm water tank at 50℃ to eliminate internal stress and avoid cracking of the sheath;

[0058] S6. Aging and shaping: The obtained cable is placed in an aging box at 90°C for 50 hours to eliminate internal stress and stabilize the structure. Finally, the cable is packaged on an ironwood drum, the outer layer of the cable is wrapped with moisture-proof paper, and both ends are sealed to prevent moisture, thereby obtaining a highly flame-retardant and fire-resistant cable product.

[0059] The insulating material preparation device includes a workbench 100, a modifying assembly 200 is provided above the workbench 100, a blanking assembly 300 is provided on the top of the modifying assembly 200, a dredging assembly 400 is provided between the workbench 100 and the modifying assembly 200, and a hot melt assembly 500 is provided on one side of the workbench 100. The modifying assembly 200 and the hot melt assembly 500 are connected through the dredging assembly 400. The blanking assembly 300 is used to store flame retardants, which are inorganic flame retardants such as metal hydroxides such as aluminum hydroxide and magnesium hydroxide. Plastic raw materials mixed with flame retardants enter the hot melt assembly 500 through the dredging assembly 400. The hot melt assembly 500 is used to heat and melt the plastic raw materials, and finally extrude them to obtain highly flame-retardant and fire-resistant insulating materials.

[0060] The modified component 200 includes a stirring piece for stirring plastic raw materials and flame retardants. During the rotation of the stirring piece, the stirring piece moves the bottom of the unloading component 300 to achieve intermittent unloading. At the same time, the stirring piece continuously presses down the top of the dredging component 400 to break up the block flame retardant blocked at the top of the dredging component 400, thereby breaking up the large blocks of flame retardant blocked at the entrance of the dredging component 400 into small pieces. In the process of the stirring piece passing over the top of the dredging component 400, the stirring piece can grind the crushed block flame retardant, that is, grind the small pieces of flame retardant into fine powder.

[0061] like Figure 4 and Figure 5 As shown, the modification component 200 includes a modification chamber 210 for mixing plastic raw materials and flame retardants, a main shaft 220 is distributed along the axis of the modification chamber 210, and is rotatably connected to the side wall of the modification chamber 210, and a stirring member includes a plurality of stirring paddles 230 radially distributed along the main shaft 220. The main shaft 220 is driven by a motor to drive the plurality of stirring paddles 230 to rotate for mixing the plastic raw materials and the flame retardant.

[0062] The improvement lies in that: a mounting seat 240 for mounting a blanking component 300 is provided on the top of the modification bin 210, so as to intermittently add flame retardants to the plastic raw materials in the modification bin 210 during the stirring of the plastic raw materials, thereby avoiding excessive application of flame retardants to the plastic raw materials at one time. The stirring paddle 230 is provided with a plurality of grinding teeth 231 at the end away from the main shaft 220. The grinding teeth 231 can further grind small pieces of flame retardant into fine powder in the process of contacting the top of the dredging component 400, so as to facilitate the full mixing of the flame retardant and the plastic raw materials in the subsequent melting stage.

[0063] During implementation, after the motor power is turned on, the motor drives the main shaft 220 coaxially connected to its output shaft to rotate, and the main shaft 220 drives its multiple radial stirring paddles 230 to rotate. During this period, the multiple stirring paddles 230 continuously pass through the bottom of the unloading component 300, intermittently pulling open the opening of the unloading component 300 to intermittently add flame retardant to the modification chamber 210. At the same time, when the multiple stirring paddles 230 pass through the top of the dredging component 400, the stirring paddles 230 continuously press down the dredging component 400, so that the large pieces of flame retardant blocking the entrance of the dredging component 400 are crushed into small pieces of flame retardant.

[0064] exist Figure 6 and Figure 7 In the embodiment, the unloading assembly 300 includes a storage bin 310 fixedly connected to the mounting base 240, and a baffle 320 is slidably connected to the bottom opening of the storage bin 310. A shift bar 330 is provided on one side of the top of the baffle 320. When the stirring paddle 230 is vertically upward, one end of the baffle 320 is provided with a fixing part for preventing the baffle 320 from falling off from the bottom of the storage bin 310.

[0065] The height of the top of the stirring paddle 230 is higher than the height of the bottom of the shift bar 330 .

[0066] Not only that, the fixing part includes a seal 340 fixedly connected to the baffle 320, the width of the seal 340 is greater than the width of the baffle 320, and a pair of limit bolts 341 are symmetrically provided on both sides away from the storage bin 310. The parts of the seal 340 at both ends that are wider than the storage bin 310 are fixedly connected with guide rods 342, and each guide rod 342 is slidingly connected to the corresponding limit bolt 341. The end of the guide rod 342 away from the seal 340 is fixedly connected to the limit cap 343, and the outer periphery of the guide rod 342 is sleeved with a first spring 344 between the limit bolt 341 and the limit cap 343.

[0067] It should be noted that when the stirring paddle 230 continuously passes through the bottom of the baffle 320, the far end of the stirring paddle 230 drives the baffle 320 to slide by pushing the dial 330, thereby exposing the opening of the storage bin 310. During the period when the baffle 320 is pushed, the limit cap 343 slides synchronously with the guide rod 342, and the limit cap 343 and the limit pin 341 with a reduced spacing compress the first spring 344 to store elastic potential energy. After the stirring paddle 230 leaves the dial 330, the first spring 344 drives the baffle 320 to reset and seal the opening at the bottom of the storage bin 310, thereby realizing intermittent addition of flame retardant to the storage bin 310.

[0068] Based on the above description, Figure 11 and Figure 12To explain the preferred effect of the dredging component 400, the dredging component 400 includes a feed channel 410 connected to the bottom of the modification bin 210, and the feed channel 410 is used to feed the plastic raw material with flame retardant mixed on the surface into the hot melt component 500. A dredging rod 420 is axially provided at the internal axis of the feed channel 410, and a grinding dredging member 430 is provided on the top of the dredging rod 420 for shielding the plastic raw material and preventing it from entering the hot melt component 500 too quickly. The inner wall of the feed channel 410 is fixedly connected to a limiting plate 440, and the dredging rod 420 is slidably connected to the limiting plate 440. The width of the limiting plate 440 is smaller than the inner diameter of the feed channel 410, and a second spring 450 is provided between the grinding dredging member 430 and the limiting plate 440 for resetting the grinding dredging member 430 that slides downward.

[0069] Furthermore, the grinding and dredging member 430 includes a plate body 431, which includes a flat plate 432 and a wedge-shaped plate 433. A plurality of grinding grooves 434 are provided on the top of the flat plate 432 and the wedge-shaped plate 433. During the rotation of the stirring paddle 230, the grinding teeth 231 first pass through the grinding grooves 434 on the top of the flat plate 432 and then pass through the grinding grooves 434 on the top of the wedge-shaped plate 433. Since the top height of the wedge-shaped plate 433 is higher than the top height of the flat plate 432 and is an inclined surface, when the grinding teeth 231 pass through the grinding grooves 434 on the top of the wedge-shaped plate 433, the wedge-shaped plate 433 is compressed to drive the dredging rod 420 to slide downward.

[0070] During operation of the above structure, when the stirring paddle 230 rotates and continuously passes over the top of the wedge plate 433, not only does the dredging rod 420 slide downward in the discharge channel 410 when the wedge plate 433 is pressed down, but the second spring 450 is compressed by the limiting plate 440 and the plate body 431 with a reduced spacing, thereby storing elastic potential energy. After the stirring paddle 230 leaves the top of the wedge plate 433, the second spring 450 releases the elastic potential energy again to reset the dredging rod 420, thereby crushing the large pieces of flame retardant blocking the entrance of the discharge channel 410. After the large pieces of flame retardant are crushed into small pieces, if they directly follow the plastic raw material into the hot melt assembly 500, uneven mixing will still occur. Therefore, after the crushed small pieces of flame retardant fall into the grinding groove 434, as the grinding teeth 231 pass through the grinding groove 434, the flame retardant is ground from the small pieces into powder, which is convenient for subsequent melting and mixing with the plastic raw material.

[0071] Next, through Figures 8-10 The specific structure of the hot melt component 500 is disclosed. The hot melt component 500 includes a hot melt chamber 510 for melting plastic raw materials and flame retardants. The hot melt chamber 510 is heated by a heating sleeve in the prior art. An auger 530 is axially provided at the axis of the hot melt chamber 510. The auger 530 is used to provide shear force to evenly mix the plastic raw materials and the flame retardant, as well as a driving force to push the molten plastic forward.

[0072] Furthermore, a main rod 520 is provided at the axis of the auger 530 , and the main rod 520 is also driven by a motor. A plurality of extrusion channels 540 are opened at one end of the hot melt chamber 510 away from the workbench 100 .

[0073] That is to say, after the plastic raw material mixed with flame retardant on its surface falls into the hot melt chamber 510 through the discharge channel 410, the power supply of the external heating sleeve of the hot melt chamber 510 is started to heat and melt the plastic raw material and the flame retardant, and then the motor drives the main rod 520 coaxially connected to its output shaft to rotate, so that the auger 530 generates a shear force to mix the plastic raw material and the flame retardant evenly, as well as a driving force to push the molten plastic forward in the hot melt chamber 510. Finally, the molten plastic is extruded from the extrusion channel 540 to obtain an insulating material with high flame retardant and fire resistant properties for preparing cables.

[0074] Example 2. This example proposes a highly flame-retardant and fire-resistant cable, including a conductor and an insulation layer. The insulation layer adopts the preparation method of the highly flame-retardant and fire-resistant cable provided in Example 1, so that the prepared cable has high flame-retardant and fire-resistant properties.

[0075] In summary, the working principle of the present invention is as follows:

[0076] First, the plastic raw materials are added into the modification bin 210, and then the main shaft 220 drives its multiple radial stirring paddles 230 to rotate. During this period, the multiple stirring paddles 230 continuously pass through the bottom of the baffle 320, and the far end of the stirring paddle 230 drives the baffle 320 to slide by pushing the dial 330, thereby exposing the opening of the storage bin 310. While the baffle 320 is being pushed, the limit cap 343 slides synchronously with the guide rod 342, and the limit cap 343 and the limit bolt 341 with a reduced spacing compress the first spring 344 to store elastic potential energy. After the stirring paddle 230 leaves the dial 330, the first spring 344 drives the baffle 320 to reset and seal the opening at the bottom of the storage bin 310, thereby realizing intermittent addition of flame retardant to the storage bin 310.

[0077] At the same time, the stirring paddle 230 continuously passes over the top of the wedge plate 433 as it rotates. During this period, not only does the dredging rod 420 slide downward in the discharge channel 410 when the wedge plate 433 is pressed down, but the second spring 450 is compressed by the limiting plate 440 and the plate body 431 with a reduced spacing, thereby storing elastic potential energy. After the stirring paddle 230 leaves the top of the wedge plate 433, the second spring 450 releases the elastic potential energy again to reset the dredging rod 420, thereby crushing the large pieces of flame retardant blocking the entrance of the discharge channel 410. After the large pieces of flame retardant are crushed into small pieces, if they directly follow the plastic raw material into the hot melt chamber 510, uneven mixing will still occur. Therefore, after the crushed small pieces of flame retardant fall into the grinding groove 434, the grinding teeth 231 are used to grind the flame retardant from small pieces into powder.

[0078] After the plastic raw material mixed with flame retardant on its surface falls into the hot melt chamber 510 through the discharge channel 410, the power supply of the external heating sleeve of the hot melt chamber 510 is started to heat and melt the plastic raw material and the flame retardant, and then the motor drives the main rod 520 coaxially connected to its output shaft to rotate, so that the auger 530 generates a shear force to mix the plastic raw material and the flame retardant evenly, as well as a driving force to push the molten plastic forward in the hot melt chamber 510. Finally, the molten plastic is extruded from the extrusion channel 540 to obtain an insulating material with high flame retardant and fire resistant properties for preparing cables.

[0079] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a highly flame-retardant and fire-resistant cable, characterized in that: The steps include: S1. Conductor preparation: anneal the copper / aluminum rods and then twist the single wires into bundles; S2. Preparation of flame retardant and fire resistant materials: adding flame retardant and plastic raw materials into an insulation material preparation device, mixing the flame retardant and plastic raw materials, and then melt-extruding to obtain a cable insulation material with high flame retardant and fire resistant properties; S3, cross-linking treatment; S4, cabling process; S5, sheath extrusion; S6, aging and shaping; The insulating material preparation device comprises a workbench (100), a modifying assembly (200) is provided above the workbench (100), a material discharge assembly (300) is provided on the top of the modifying assembly (200), a dredging assembly (400) is provided between the workbench (100) and the modifying assembly (200), and a hot melt assembly (500) is provided on one side of the workbench (100); The modified component (200) includes a stirring member. During the rotation of the stirring member, the stirring member reciprocates to move the bottom of the unloading component (300) to achieve intermittent unloading. At the same time, the stirring member continuously presses down the top of the unblocking component (400) to crush the block flame retardant blocked at the top of the unblocking component (400). During the process of the stirring member passing through the top of the unblocking component (400), the stirring member can grind the crushed block flame retardant.

2. The method for preparing a highly flame-retardant and fire-resistant cable according to claim 1, wherein: The modification component (200) includes a modification chamber (210) for mixing plastic raw materials and flame retardants. A main shaft (220) is provided at the axis of the modification chamber (210). The main shaft (220) is rotatably connected to the side wall of the modification chamber (210). The stirring member includes a plurality of stirring paddles (230) distributed radially along the main shaft (220).

3. The method for preparing a highly flame-retardant and fire-resistant cable according to claim 2, wherein: A mounting seat (240) is provided on the top of the modification chamber (210), and a plurality of grinding teeth (231) are provided on the end of the stirring paddle (230) away from the main shaft (220).

4. The method for preparing a highly flame-retardant and fire-resistant cable according to claim 3, wherein: The unloading assembly (300) includes a storage bin (310) fixedly connected to a mounting base (240), a baffle (320) being slidably connected to a bottom opening of the storage bin (310), a shift bar (330) being provided on one side of the top of the baffle (320), and when the stirring paddle (230) is vertically upward, the height of the top of the stirring paddle (230) is higher than the height of the bottom of the shift bar (330), and a fixing member for preventing the baffle (320) from falling off from the bottom of the storage bin (310) is provided at one end of the baffle (320).

5. The method for preparing a highly flame-retardant and fire-resistant cable according to claim 4, characterized in that: The fixing member includes a seal (340) fixedly connected to the baffle (320), the width of the seal (340) is greater than the width of the baffle (320), and a pair of limit bolts (341) are symmetrically provided on two sides away from the storage bin (310), and the parts of the seal (340) at both ends that are wider than the storage bin (310) are fixedly connected to guide rods (342), and each guide rod (342) is slidably connected to the corresponding limit bolt (341), and one end of the guide rod (342) away from the seal (340) is fixedly connected to a limit cap (343), and a first spring (344) is sleeved on the periphery of the guide rod (342) between the limit bolt (341) and the limit cap (343).

6. The method for preparing a highly flame-retardant and fire-resistant cable according to claim 3, wherein: The dredging assembly (400) includes a feed channel (410) connected to the bottom of the modified bin (210), a dredging rod (420) is axially provided at the inner axis of the feed channel (410), a grinding dredging piece (430) is provided on the top of the dredging rod (420), the inner wall of the feed channel (410) is fixedly connected to a limiting plate (440), the dredging rod (420) is slidably connected to the limiting plate (440), the width of the limiting plate (440) is smaller than the inner diameter of the feed channel (410), and a second spring (450) is provided between the grinding dredging piece (430) and the limiting plate (440).

7. The method for preparing a highly flame-retardant and fire-resistant cable according to claim 6, characterized in that: The grinding and dredging member (430) includes a plate body (431), and the plate body (431) includes a flat plate (432) and a wedge plate (433). The tops of the flat plate (432) and the wedge plate (433) are both provided with a plurality of grinding grooves (434). During the rotation of the stirring paddle (230), the grinding teeth (231) first pass through the grinding grooves (434) on the top of the flat plate (432) and then pass through the grinding grooves (434) on the top of the wedge plate (433).

8. The method for preparing a highly flame-retardant and fire-resistant cable according to claim 1, wherein: The hot melt assembly (500) comprises a hot melt chamber (510) for melting plastic raw materials and flame retardants, and an auger (530) is axially arranged at the axis of the hot melt chamber (510).

9. The method for preparing a highly flame-retardant and fire-resistant cable according to claim 8, wherein: A main rod (520) is provided at the axis of the auger (530), and a plurality of extrusion channels (540) are opened at one end of the hot melt cavity (510) away from the workbench (100).

10. A highly flame-retardant and fire-resistant cable, characterized by: The invention comprises a conductor and an insulating material, wherein the insulating material is prepared by the preparation method of the highly flame-retardant and fire-resistant cable according to any one of claims 2 to 9.

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