Self-lubricating flexible high extrusion fireproof cable, fireproof inner protective material and preparation method of the material

Abstract

The invention discloses a self-lubricating flexible high extrusion amount fireproof inner protective material and a cable containing shell powder and vermiculite powder for cables, comprising the following materials by mass: 60-120 parts of shell powder, 12-28 parts of vermiculite powder, 10-30 parts of silicon dioxide solution, 15-32 parts of calcium hydroxide, 30-80 parts of water glass, and 20-60 parts of aluminum hydroxide. Compared with the prior art, the present invention uses shell powder and vermiculite powder to form a self-lubricating fireproof material and other materials to form a high extrusion amount of flexible fireproof inner protective material, while ensuring the quality of the fireproof inner protective material, greatly improving the production efficiency of the fireproof cable.

Description

Technical Field

[0001] The invention relates to a self-lubricating, flexible, high-extrusion-volume fireproof inner protective material for cables containing shell powder and vermiculite powder, a fireproof cable made of the material and a preparation method of the material, in particular to a fireproof cable with a voltage level of 1 kV or below. Background Art

[0002] With the sustained and rapid growth of my country's economy, various high-rise buildings, large commercial venues and other public facilities have been vigorously developed, which has brought higher requirements to fire safety work.

[0003] In recent years, the frequency of fire accidents has been increasing. When a fire occurs, ordinary cables are not resistant to burning, and the insulation is easily damaged and short-circuited, resulting in power supply interruption and the failure of firefighting equipment to work properly, which brings great difficulties to the evacuation of trapped personnel and firefighting rescue work. As people have higher and higher requirements for fire safety, various fireproof cables have been used;

[0004] The so-called fireproof cable is a cable that can keep the line open in a fire scene, allowing the power to be transmitted normally and meeting the fireproof standards for line integrity requirements;

[0005] The most commonly used cables are fireproof cables of 1kV and below; they are mainly divided into rigid mineral insulated fireproof cables and flexible fireproof cables.

[0006] Rigid mineral insulated fireproof cables are made through mineral insulation filling and copper metal sheath drawing process; the equipment investment is high, the process is complex, the manufacturing and production speed is very slow, and the price is expensive; and the protection requirements for the filled insulation material are high, the installation is cumbersome, and it cannot be bent. The insulation material is very easy to absorb moisture and cannot be used.

[0007] Flexible fireproof cables were introduced in recent years. This type of cable mainly uses mica as insulation and extrudes a fireproof material layer on the outside of the wire core; or extrudes a fireproof material layer on the surface of the metal sheath to achieve a certain degree of flexibility and fireproof performance. However, in the current production of flexible fireproof cables, the fireproof material is extremely difficult to extrude when extruding the fireproof material layer, the production speed is slow, and the efficiency is extremely low; and the fireproof material layer is hard after extrusion and is easy to crack; cracking of the fireproof material layer seriously affects the fireproof performance of the cable.

[0008] The shortcomings of existing flexible fireproof cables are: when the fireproof material layer of the fireproof cable is extruded by an extruder, the friction coefficient is large, the extrusion volume is small, the extrusion speed is slow, and the production efficiency is low, which affects the production and delivery of fireproof cables; the fireproof material layer of the cable is not flexible enough after extrusion, is not easy to bend, and is very easy to crack, affecting the fireproof performance of the cable.

[0009] The above problems need to be improved. Summary of the invention

[0010] The purpose of the present invention is to provide a self-lubricating flexible high-extrusion fireproof cable, a fireproof inner protective material and a preparation method of the material. The problem to be solved is to improve the production efficiency of the flexible fireproof cable, ensure the softness and quality of the flexible fireproof cable while reducing the cost and improving its economy.

[0011] To achieve the above object, the present invention adopts the following technical solution:

[0012] A 1kV and below self-lubricating flexible high extrusion fireproof cable, comprising a conductor, a mica layer extruded outside the conductor, a cross-linked polyethylene insulation layer extruded outside the mica tape layer, a ceramic silicone tape wrapped outside the cross-linked polyethylene insulation layer, forming at least one wire core, the wire core is extruded with a fireproof inner protective layer, a highly flame-retardant halogen-free wrapping tape is wrapped outside the fireproof inner protective layer, a stainless steel corrugated tube with an expandable fire-retardant coating coated on the surface of the highly flame-retardant halogen-free wrapping tape is coated outside, and the outermost layer is extruded with a highly flame-retardant and environmentally friendly outer sheath.

[0013] A fireproof inner sheath material for self-lubricating flexible high extrusion fireproof cables of 1 kV and below, comprising the following materials in parts by mass: 60-120 parts of shell powder, 12-28 parts of vermiculite powder, 10-30 parts of silicon dioxide solution, 15-32 parts of calcium hydroxide, 30-80 parts of water glass and 20-60 parts of aluminum hydroxide.

[0014] A fireproof inner sheath material for self-lubricating flexible high-extrusion fireproof cables of 1 kV and below, composed of the following materials in parts by mass: 90 parts of shell powder, 20 parts of vermiculite powder, 20 parts of silicon dioxide solution, 23.5 parts of calcium hydroxide, 55 parts of water glass, and 40 parts of aluminum hydroxide.

[0015] As a further improvement, the silicon dioxide solution is a 20% silicon dioxide solution.

[0016] Further improvement, the water glass is 51 degree water glass, which is used as an adhesive. The water glass has good fire resistance and plays a role of mixing and bonding, which is convenient for extrusion and molding.

[0017] A method for preparing the fireproof inner sheath material for the self-lubricating flexible high extrusion fireproof cable of 1 kV and below comprises the following steps:

[0018] 1) Screening and measuring each material;

[0019] 2) First, pour the shell powder and vermiculite powder into a closed mixer according to the formula ratio and mix for 1 minute;

[0020] 3) Pour calcium hydroxide, aluminum hydroxide and 51-degree water glass into the agitator in step 2) according to the formula ratio and mix for 5 minutes;

[0021] 4) Finally, 20% silicon dioxide solution is added to the mixture of step 3) according to the formula ratio and stirred for 2 minutes to obtain a soft mud-like fireproof interior protection material.

[0022] The shell powder and vermiculite powder of the present invention are both lubricants and fillers. The main component of the shell powder is calcium carbonate, which is the main filling material. The shell powder and vermiculite powder have unique pores and capillary structures, and the gaps are filled with each other, which significantly reduces the resistance with the inner wall of the extruder. The lubrication effect is significantly increased by several times compared with the single use of shell powder or vermiculite powder, and a high extrusion volume of the extruder is achieved, which greatly improves the production efficiency. The water breathing function and exchange adsorption function of the shell powder and vermiculite powder enhance the softener effect of the silicon dioxide solution, maintain the wetness and softness of the fireproof material layer, and prevent the fireproof material layer from cracking when the cable is normally bent, thereby ensuring the fireproof performance of the cable. The shell powder and vermiculite powder are abundant in resources, economical and easy to obtain, and have good economy.

[0023] The aluminum hydroxide described in the present invention is a highly efficient flame retardant, which releases bound water when decomposed into aluminum oxide by heat, thereby reducing the surface temperature and having good fire resistance.

[0024] Compared with the prior art, the present invention adds shell powder and vermiculite powder as lubricants and fillers to the fireproof inner protective material, and forms the fireproof inner protective material with softener silica solution and other materials. The fireproof inner protective material has a high extrusion volume when extruded by an extruder, which greatly improves the production efficiency of flexible fireproof cables, ensures the softness of the fireproof material layer, and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of Embodiment 7 of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of Example 8 of the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be clearly and completely described below in combination with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] A fireproof inner sheath material for self-lubricating flexible high extrusion fireproof cables of 1 kV and below, comprising the following materials in parts by mass: 60-120 parts of shell powder, 12-28 parts of vermiculite powder, 10-30 parts of silicon dioxide solution, 15-32 parts of calcium hydroxide, 30-80 parts of water glass and 20-60 parts of aluminum hydroxide.

[0029] Embodiment 1:

[0030] A fireproof inner sheath material for self-lubricating flexible high-extrusion fireproof cables of 1 kV and below, composed of the following materials in parts by mass: 60 parts of shell powder, 12 parts of vermiculite powder, 10 parts of silicon dioxide solution, 26 parts of calcium hydroxide, 75 parts of water glass, and 40 parts of aluminum hydroxide.

[0031] Embodiment 2:

[0032] A fireproof inner sheath material for self-lubricating flexible high-extrusion fireproof cables of 1 kV and below, composed of the following materials in parts by mass: 120 parts of shell powder, 28 parts of vermiculite powder, 20 parts of silicon dioxide solution, 20 parts of calcium hydroxide, 50 parts of water glass, and 40 parts of aluminum hydroxide.

[0033] Embodiment 3:

[0034] A fireproof inner sheath material for self-lubricating flexible high-extrusion fireproof cables of 1 kV and below, composed of the following materials in parts by mass: 105 parts of shell powder, 25 parts of vermiculite powder, 25 parts of silicon dioxide solution, 15 parts of calcium hydroxide, 35 parts of water glass, and 65 parts of aluminum hydroxide.

[0035] Embodiment 4:

[0036] A fireproof inner sheath material for self-lubricating flexible high-extrusion fireproof cables of 1 kV and below, composed of the following materials in parts by mass: 90 parts of shell powder, 20 parts of vermiculite powder, 21 parts of silicon dioxide solution, 25 parts of calcium hydroxide, 85 parts of water glass, and 60 parts of aluminum hydroxide.

[0037] Embodiment 5:

[0038] A fireproof inner sheath material for self-lubricating flexible high-extrusion fireproof cables of 1 kV and below, composed of the following materials in parts by mass: 100 parts of shell powder, 18 parts of vermiculite powder, 22 parts of silicon dioxide solution, 25 parts of calcium hydroxide, 58 parts of water glass, and 50 parts of aluminum hydroxide.

[0039] Embodiment 6:

[0040] A fireproof inner sheath material for self-lubricating flexible high-extrusion fireproof cables of 1 kV and below, composed of the following materials in parts by mass: 90 parts of shell powder, 20 parts of vermiculite powder, 20 parts of silicon dioxide solution, 23.5 parts of calcium hydroxide, 55 parts of water glass, and 40 parts of aluminum hydroxide.

[0041] Examples 1-6 are all produced and prepared by the following method: a method for preparing a fireproof inner sheath material for a 1 kV or less self-lubricating flexible high extrusion fireproof cable, comprising the following steps:

[0042] 1) Screening and measuring each material;

[0043] 2) First, pour the shell powder and vermiculite powder into a closed mixer according to the formula ratio and mix for 1 minute;

[0044] 3) Pour calcium hydroxide, aluminum hydroxide and 51-degree water glass into the agitator in step 2) according to the formula ratio and mix for 5 minutes;

[0045] 4) Finally, add 20% silicon dioxide solution according to the formula ratio and stir the mixture in step 3) for 2 minutes to obtain a soft mud-like fireproof interior protection material;

[0046] When manufacturing the cable, according to the existing technology, a cold feed extruder is used to extrude the soft mud-like fireproof material and coat it on the outside of the wire core to form the fireproof inner sheath of the cable.

[0047] Use XJW150 cold feed extruder to extrude soft mud fireproof material and coat it on the outside of the wire core to form the fireproof inner sheath of the cable; the extruder parameters are screw diameter: 150㎜, aspect ratio: 14:1, screw compression ratio: 1.64, main engine power: 132kw;

[0048] The specific parameters of the extrusion of the embodiment are shown in Table 1:

[0049] Table 1

[0050]

[0051] Under the same conditions, it can be seen from the data comparison in Table 1 that:

[0052] The fireproof inner protective material layer prepared by embodiment 1 has a small number of shell powder and vermiculite powder, a large extrusion resistance, a small amount of extrusion, a very low production efficiency, a hard fireproof layer and cracks, which is not ideal; the fireproof inner protective material layer prepared by embodiment 2 has a large number of shell powder and vermiculite powder, good lubricity, but is too soft and has sagging, the quality cannot be guaranteed and affects the subsequent production process; the fireproof inner protective material layer prepared by embodiment 3 has a moderate number of shell powder and vermiculite powder, but the fireproof material layer is soft, occasionally has sagging, and aluminum hydroxide The fraction is large and the cost is high; the fire-proof inner protective material layer prepared by using embodiment 4 has insufficient lubricity, small extrusion amount and low production efficiency due to the small proportion of shell powder and vermiculite powder; the fire-proof inner protective material layer prepared by using embodiment 5 has a high extrusion amount during extrusion, moderate softness of the fire-proof inner protective material layer, good surface quality and low cost, which is ideal; the fire-proof inner protective material layer prepared by using embodiment 6 has a high extrusion amount during extrusion, high softness of the fire-proof inner protective material layer, good surface quality and low cost, which is ideal and the best solution.

[0053] Embodiment 7:

[0054] like Figure 1As shown, a self-lubricating flexible high-extrusion fireproof cable with a voltage level of 0.6 / 1kV comprises a conductor 1-1, a mica tape layer 1-2 extruded outside the conductor, a cross-linked polyethylene insulation layer 1-3 extruded outside the mica layer, a ceramic silicone tape 1-4 wrapped outside the cross-linked polyethylene insulation layer, forming a wire core 1, a fireproof inner protective layer 2 extruded outside the wire core, a highly flame-retardant halogen-free wrapping tape 3 wrapped outside the fireproof inner protective layer, a stainless steel corrugated tube 4 coated with an intumescent fire-retardant coating on the surface of the highly flame-retardant halogen-free wrapping tape, and an outermost extruded highly flame-retardant environmentally friendly outer sheath 5; wherein the fireproof inner protective layer 2 is prepared using the component materials in Examples 1-6.

[0055] Embodiment 8:

[0056] like Figure 2 As shown, a self-lubricating flexible high extrusion fireproof cable with a voltage level of 0.6 / 1kV includes a conductor 1-1, a mica tape layer 1-2 extruded outside the conductor, a cross-linked polyethylene insulation layer 1-3 extruded outside the mica layer, and a ceramic silicone tape 1-4 wrapped outside the cross-linked polyethylene insulation layer to form a core 1. Three cores with the same structure are twisted into a cable core ( Figure 2 Only one wire core is shown in the complete structural diagram, and the other two are not fully shown), the wire core is extruded with a fireproof inner protective layer 2, a highly flame-retardant halogen-free wrapping tape 3 is wrapped outside the fireproof inner protective layer, a stainless steel corrugated tube 4 with an intumescent fire-retardant coating is coated on the surface of the highly flame-retardant halogen-free wrapping tape, and the outermost layer is extruded with a highly flame-retardant and environmentally friendly outer sheath 5. Among them, the fireproof inner protective layer 2 is prepared by using the component materials in Example 5.

[0057] The cable using the self-lubricating, flexible, high-extrusion-volume fireproof inner sheath material containing shell powder and vermiculite powder of the present invention is tested according to national standards, and the fire resistance is tested according to BS standards.

[0058] The DC resistance of the conductor is tested in accordance with Part 4: DC resistance test of conductor in GB / T3048.4-2007 "Electrical performance test methods for wires and cables", and the test results meet the requirements of GB / T3956-2008 "Conductors of cables".

[0059] The AC voltage test is in accordance with GB / T3048.8-2007 "Electrical Performance Test Methods for Wires and Cables" Part 8: AC voltage test. The test voltage is the power frequency voltage 4U0, and there is no breakdown for 4h.

[0060] The insulation tensile strength is tested according to the first part of GB / T2951.1-1997 "General Test Methods for Cable Insulation and Sheath Materials" General Test Methods Section 1 Mechanical Properties Test, and the result is not less than 12.5N / mm 2 .

[0061] The insulation breaking elongation shall be tested in accordance with the first part general test methods section 1 mechanical properties test of GB / T2951.1-1997 "General test methods for cable insulation and sheath materials", and the result shall not be less than 200%.

[0062] The sheath tensile strength shall be tested in accordance with the mechanical properties test in Part 1 General Test Methods Section 1 of GB / T2951.1-1997 "General Test Methods for Cable Insulation and Sheath Materials", and the result shall not be less than 9MPa.

[0063] The sheath breaking elongation shall be tested in accordance with the first part general test methods section 1 mechanical properties test of GB / T2951.1-1997 "General test methods for cable insulation and sheath materials", and the result shall not be less than 125%.

[0064] The fire resistance performance is tested according to the test method of BS8491:2008 "Method for assessing the fire integrity of large diameter power cables used in smoke and heat control systems and certain other ongoing fire safety system components". The result is that the fire resistance test time is not less than 180 minutes, the fuse is not broken, and the indicator light is not extinguished.

[0065] After testing: the fire resistance performance of the cables in Example 7 and Example 8 meets the requirements of BS8491:2008 standard, and other performances meet the requirements of relevant national standards.

[0066] Under the same production conditions, the extrusion data of the fireproof layer material of this patented cable and the existing flexible fireproof cable are compared in Table 2:

[0067] Table 2

[0068]

[0069] As can be seen from Table 2, the extrusion volume of the fireproof material layer of the existing flexible fireproof cable is low and the material is hard. The extrusion volume of the fireproof layer inner sheath material of the patented cable is increased by 60%, and the softness is moderate, which greatly improves the production efficiency.

[0070] This patent breaks the principle of the existing technology that the fireproof material layer of the flexible fireproof cable is based on hydroxide with small extrusion volume and low production efficiency. This patent uses shell powder and vermiculite powder as both fillers and lubricants, which ensures the fire resistance and other properties of the fireproof cable while having a high extrusion volume, greatly improving the production efficiency and having good economy.

[0071] The present invention has many specific application paths. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A self-lubricating flexible high extrusion fireproof cable, characterized in that: It comprises a conductor, a mica tape layer extruded outside the conductor, a cross-linked polyethylene insulation layer extruded outside the mica layer, a ceramic silicone tape wrapped outside the cross-linked polyethylene insulation layer, forming at least one wire core, a fireproof inner sheath extruded outside the wire core, a highly flame-retardant halogen-free wrapping tape wrapped outside the fireproof inner sheath, a stainless steel corrugated pipe coated with an intumescent fire-retardant coating on the surface of the highly flame-retardant halogen-free wrapping tape, and a highly flame-retardant and environmentally friendly outer sheath extruded on the outermost layer; Wherein, the fireproof inner protective layer is composed of the following materials in parts by mass: 60-120 parts of shell powder, 12-28 parts of vermiculite powder, 10-30 parts of silicon dioxide solution, 15-32 parts of calcium hydroxide, 30-80 parts of water glass, and 20-60 parts of aluminum hydroxide.

2. The self-lubricating, flexible, high extrusion-volume fireproof cable according to claim 1, characterized in that: The number of the wire cores is one or three.

3. A self-lubricating, flexible, high extrusion-volume fireproof cable according to claim 1, characterized in that: The fireproof inner protective layer is composed of the following materials in parts by mass: 90 parts of shell powder, 20 parts of vermiculite powder, 20 parts of silicon dioxide solution, 23.5 parts of calcium hydroxide, 55 parts of water glass, and 40 parts of aluminum hydroxide.

4. A self-lubricating, flexible, high extrusion-volume fireproof cable according to claim 1 or 3, characterized in that: The silicon dioxide solution is a 20% silicon dioxide solution.

5. A self-lubricating, flexible, high extrusion-volume fireproof cable according to claim 1 or 3, characterized in that: The water glass is 51 degree water glass.

6. A method for preparing the fireproof inner sheath material of the fireproof inner sheath in the self-lubricating flexible high extrusion fireproof cable according to any one of claims 1 to 5, comprising the following steps: 1) Screen and measure each material; 2) Pour shell powder and vermiculite powder into a closed mixer according to the formula ratio and mix for 1 minute; 3) Pour calcium hydroxide, aluminum hydroxide and 51-degree water glass into the mixer in step 2) according to the formula ratio and mix for 5 minutes; 4) Finally, add 20% silicon dioxide solution according to the formula ratio and stir the mixture in step 3) for 2 minutes to obtain a soft mud-like fireproof interior protective material.

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