Flame-retardant polyester fiber paper-based cable core tape and preparation method thereof

Abstract

This invention discloses a flame-retardant polyester fiber paper-based cable core wrapping tape and its preparation method. The preparation method includes the following steps: S1, grinding and mixing hydrotalcite and carboxymethyl cellulose to obtain a flame-retardant filler; S2, mixing polyester fiber, aramid precipitated fiber, and the flame-retardant filler obtained in step S1 to form a slurry; S3, dispersing the slurry obtained in step S2 in water, then descaling it, and dehydrating and forming it on a paper forming machine to obtain a wet paper web; S4, drying and hot-pressing the wet paper web obtained in step S3 to obtain the flame-retardant polyester fiber paper-based cable core wrapping tape. Addressing the problems of traditional flame-retardant cable core wrapping tape materials releasing halogens and toluene, this invention uses the inorganic mineral hydrotalcite as a flame retardant and regulates its adhesion and paper retention rate by compounding with carboxymethyl cellulose. This solves practical production problems and expands the flame-retardant function of the polyester fiber paper-based cable core wrapping tape.

Description

Technical Field

[0001] This invention relates to cable core wrapping tape, specifically to a flame-retardant polyester fiber paper-based cable core wrapping tape and its preparation method. Background Technology

[0002] With rapid economic development, wires and cables are widely used in various industries and fields. However, with the frequent occurrence of electrical fires, the flame retardancy of wires and cables has gradually attracted worldwide attention. The large amounts of smoke and toxic, corrosive gases released when cables burn are dangerous factors in fires, hindering safe evacuation and firefighting efforts, and causing serious loss of life and property.

[0003] High flame-retardant wrapping tape maintains the insulation stability of cables under open flame conditions, making it a crucial insulation layer for manufacturing special cables, especially fire-resistant wires and cables. Currently, in the field of high flame-retardant wrapping tape, domestic products vary in performance and formulation. Internationally renowned high flame-retardant wrapping tapes from DuPont (USA) and Toray (Japan), while exhibiting excellent performance, do not simultaneously possess properties such as flexibility, anti-aging, and fire resistance. Furthermore, the flame retardants used in the preparation of most wrapping tapes exhibit several issues. On the one hand, halogenated organic flame retardants are used, which, while providing good flame retardant effects, release secondary pollutants and fumes during combustion. On the other hand, inorganic flame retardants often utilize silicone as an adhesive component, inevitably requiring toluene as a diluent, which poses environmental risks. Therefore, neither domestic nor international products currently possess the high-quality wrapping material technology required for manufacturing wires and cables for China's world-leading high-speed trains, nuclear power, and other related fields. Summary of the Invention

[0004] To address the pollution issues associated with the use of halogenated organic flame retardants and silicone adhesives in high flame-retardant cable tapes, this invention provides a flame-retardant polyester fiber paper-based cable core tape and its preparation method. This preparation method combines surface pretreatment with flame retardant hydrotalcite with a wet paper forming process, solving the problems of high halogen content, poor oxidation resistance, low flame retardancy, and environmental unfriendliness associated with similar products both domestically and internationally.

[0005] To achieve the above objectives, the present invention provides a method for preparing flame-retardant polyester fiber paper-based cable core wrapping tape, the method comprising the following steps:

[0006] S1. Grind and mix hydrotalcite and carboxymethyl cellulose to obtain flame-retardant filler;

[0007] S2. Mix and adjust the polyester fiber, aramid precipitated fiber and the flame retardant filler obtained in step S1 into a slurry.

[0008] S3. Disperse the pulp obtained in step S2 in water, then loosen it, and dehydrate and form it on a paper forming machine to obtain a wet paper web.

[0009] S4. After drying and hot pressing the wet paper web obtained in step S3, flame-retardant polyester fiber paper-based cable core wrapping tape is obtained.

[0010] To address the issues of traditional flame-retardant cable core wrapping materials releasing halogens and toluene, this invention uses the inorganic mineral hydrotalcite as a flame retardant. Based on the principle that hydrotalcite releases water vapor and carbon dioxide when heated, reducing the oxygen concentration of combustion gases, it plays a role in flame retardancy. At the same time, the gases released by hydrotalcite absorb heat, which can lower the ambient temperature and slow down the combustion rate. Therefore, it has a high smoke suppression and high flame retardant effect.

[0011] However, due to the small particle size of hydrotalcite, traditional papermaking processes suffer from significant loss and difficulty in forming the paper. This invention combines hydrotalcite with carboxymethyl cellulose. On the one hand, carboxymethyl cellulose increases the viscosity of the pulp components and reduces the sedimentation rate of hydrotalcite during water dispersion, thus providing conditions for paper forming. On the other hand, the abundant hydroxyl groups on the surface of carboxymethyl cellulose provide bridging between the fiber components and the flame retardant, preventing paper fiber shedding and dusting. In addition, carboxymethyl cellulose can replenish the nanopores of the fibers, further improving the paper's insulation properties.

[0012] Furthermore, this invention utilizes the excellent water dispersibility of aramid precipitated fibers as an auxiliary dispersion and forming fiber. It has a high temperature resistance, is self-extinguishing, and contains no silicone adhesive, thus solving the shortcomings of existing commercially available cable core wrapping adhesives that emit volatile toluene and other VOCs pollution. At the same time, it endows the prepared cable core wrapping material with high flexibility, which can withstand bending and folding in practical applications.

[0013] The above-mentioned process flow of the present invention includes preparation of hydrotalcite filler, paper pulp formulation, wet process forming, dewatering and drying, and high temperature enhanced bonding. While ensuring rapid forming of polyester fiber paper-based cable core wrapping tape, it has the advantages of green and environmentally friendly process, low noise, and no chemical reagent release.

[0014] As a preferred embodiment of the present invention, in step S1, the mass percentage of hydrotalcite in the flame-retardant filler is 95-98%, and the mass percentage of carboxymethyl cellulose is 2-5%.

[0015] Specifically, in step S1, the grinding and mixing process takes more than 20 minutes.

[0016] Preferably, in step S2, the mass ratio of the polyester fiber, the aramid precipitated fiber and the flame retardant filler is (20~30):(40~50):(20~60).

[0017] The above-mentioned ratio of polyester fiber, aramid precipitated fiber and flame retardant filler achieves the highest addition amount of polyester fiber while maintaining paper uniformity and improving bonding, thus maximizing the flame retardant properties of the paper.

[0018] Preferably, in step S2, the linear density of the polyester fiber is 60~100 dtex and the length is 4~6 mm.

[0019] Specifically, in step S3, the rotation speed is reduced to 18,000-20,000 revolutions.

[0020] Specifically, in step S4, the drying temperature is 110~120℃, the vacuum degree is 8~12Mpa, and the time is 10~15min.

[0021] This drying condition not only achieves energy saving and consumption reduction, but also shortens the preparation process cycle to the greatest extent.

[0022] Specifically, in step S4, the hot pressing temperature is 180~190℃, the pressure is 8~10 MPa, and the time is 4~8 min.

[0023] A second aspect of the present invention provides a flame-retardant polyester fiber paper-based cable core wrapping tape, which is prepared by the above-described preparation method.

[0024] Preferably, the weight of the flame-retardant polyester fiber paper-based cable core wrapping tape is 60~80g.

[0025] Through the above technical solution, the present invention achieves the following beneficial effects:

[0026] 1. In response to the problems of traditional flame-retardant cable core wrapping materials releasing halogens and toluene, this invention uses inorganic mineral hydrotalcite as a flame retardant and regulates its adhesion and paper retention rate by compounding with carboxymethyl cellulose. Based on solving practical production problems, this invention expands the flame-retardant function of polyester fiber paper-based cable core wrapping.

[0027] 2. The reagents used in the process of this invention are all conventional pharmaceutical reagents, which are non-toxic, inexpensive, and easy to obtain. The equipment used is conventional papermaking equipment, which lays the foundation for the marketization of the product, controls the manufacturing cost, and improves market competitiveness. Attached Figure Description

[0028] Figure 1 This is a SEM image of the cable core wrapping prepared in Embodiment 1 of the present invention. Detailed Implementation

[0029] The specific embodiments of the present invention will be described in detail below with reference to examples. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0030] In the following examples, both hydrotalcite and carboxymethyl cellulose are commercially available. The hydrotalcite has a particle size of 1-3 μm, and the carboxymethyl cellulose has a width of 5-10 μm and a length of 10-100 μm.

[0031] Example 1

[0032] The preparation method of flame-retardant polyester fiber paper-based cable core wrapping includes the following steps:

[0033] S1. Weigh 98g of hydrotalcite powder and 2g of carboxymethyl cellulose respectively, pour them into a grinder and grind for 20min to obtain a compound hydrotalcite filler flame retardant.

[0034] S2. Select 60dtex polyester fiber and cut it into short fibers with a length of 6mm for later use;

[0035] S3, according to a quantitative amount of 60g / m 2 The fiber slurry was prepared by selecting compound hydrotalcite filler flame retardant, polyester short fiber, and aramid precipitated fiber, and the slurry was prepared according to a mass ratio of 20:40:40.

[0036] S4. Mix and disperse the pulp in about 1L of water, then decompose it at 20,000 revolutions, and then dehydrate and form it on the paper forming machine.

[0037] S5. Dry the wet paper web obtained in the previous step at 120℃ and 10MPa vacuum for 10 minutes to obtain polyester fiber base paper.

[0038] S6. The obtained polyester fiber base paper is hot-pressed at 185℃ and 8MPa for 5 minutes to obtain a high flame-retardant polyester fiber paper-based cable core wrapping. Its SEM image is shown below. Figure 1 As shown in the figure, polyester fibers are interwoven and dispersed, while hydrotalcite particles fill the surrounding area and adhere tightly.

[0039] Example 2

[0040] The preparation method of flame-retardant polyester fiber paper-based cable core wrapping includes the following steps:

[0041] S1. Weigh 95g of hydrotalcite powder and 5g of carboxymethyl cellulose respectively, pour them into a grinder and grind for 30 minutes to obtain a compound hydrotalcite filler flame retardant.

[0042] S2. Select 100dtex polyester fiber and cut it into short fibers with a length of 4mm for later use;

[0043] S3, according to a quantitative amount of 80g / m 2The fiber slurry was prepared by selecting compound hydrotalcite filler flame retardant, polyester short fiber, and aramid precipitated fiber, and the slurry was prepared according to a mass ratio of 30:50:20.

[0044] S4. Mix and disperse the pulp in about 1L of water, then decompose it at 18,000 revolutions, and then dehydrate and form it on the paper forming machine.

[0045] S5. Dry the wet paper web obtained in the previous step at 110°C and 8MPa vacuum for 15 minutes to obtain polyester fiber base paper.

[0046] S6. The obtained polyester fiber base paper is hot-pressed at 180℃ and 10MPa pressure for 8 minutes to obtain a high flame-retardant polyester fiber paper-based cable core wrapping tape.

[0047] Example 3

[0048] The preparation method of flame-retardant polyester fiber paper-based cable core wrapping includes the following steps:

[0049] S1. Weigh 96g of hydrotalcite powder and 4g of carboxymethyl cellulose respectively, pour them into a grinder and grind for 40min to obtain a compound hydrotalcite filler flame retardant.

[0050] S2. Select 80dtex polyester fiber and cut it into short fibers with a length of 5mm for later use;

[0051] S3, according to a quantitative 70g / m 2 The fiber slurry was prepared by selecting compound hydrotalcite filler flame retardant, polyester short fiber, and aramid precipitated fiber, and the slurry was prepared according to a mass ratio of 25:45:30.

[0052] S4. Mix and disperse the pulp in about 1L of water, then decompose it at 20,000 revolutions, and then dehydrate and form it on the paper forming machine.

[0053] S5. Dry the wet paper web obtained in the previous step at 120℃ and 12MPa vacuum for 12 minutes to obtain polyester fiber base paper.

[0054] S6. The obtained polyester fiber base paper is hot-pressed at 190℃ and 8MPa pressure for 4 minutes to obtain a high flame-retardant polyester fiber paper-based cable core wrapping tape.

[0055] Comparative Example 1

[0056] Other conditions are the same as in Example 1, except that carboxymethyl cellulose is omitted.

[0057] Comparative Example 2

[0058] Other conditions are the same as in Example 1, except that the hydrotalcite powder is omitted.

[0059] Comparative Example 3

[0060] Other conditions are the same as in Example 1, except that the hydrotalcite powder and carboxymethyl cellulose are mixed by stirring.

[0061] Comparative Example 4

[0062] Other conditions are the same as in Example 1, except that the aramid precipitated fibers are replaced with polyester chopped fibers.

[0063] Performance testing

[0064] The tapes prepared in Examples 1-3 and Comparative Examples 1-4 were tested for dielectric strength, limiting oxygen index, folding endurance, heat resistance, tensile strength, and environmental protection requirements. The test standards for each performance are as follows:

[0065] Dielectric strength: GB / T 42125.10-2022

[0066] Limiting Oxygen Index: GB / T 5454-1997

[0067] Flexural endurance: GB / T 457-2008

[0068] Heat resistance: GB / T 11026.1-2003

[0069] Tensile strength: GB / T 12914-2018

[0070] Environmental protection requirements: GB / T 17650.1-2021

[0071] The test results are shown in Table 1.

[0072] Table 1. Test Results of Cable Core Wrapping Performance

[0073]

[0074] As can be seen from Table 1, the flame-retardant polyester fiber paper-based cable core wrapping tape (Examples 1-3) prepared by the present invention has excellent dielectric strength, limiting oxygen index, folding endurance, heat resistance, tensile strength and environmental performance.

[0075] Comparing the data of Example 1 and Comparative Example 1, it can be seen that when carboxymethyl cellulose is omitted, the dielectric strength, limiting oxygen index, folding endurance, and tensile strength of the cable core wrapping tape all decrease. This is because without the effect of carboxymethyl cellulose, on the one hand, the hydrotalcite will be lost during the papermaking process, resulting in a decrease in the flame retardant performance of the cable core wrapping tape. On the other hand, without the bonding and bridging effect of carboxymethyl cellulose, the density of the paper structure will decrease, resulting in a decrease in the insulation and mechanical properties of the cable core wrapping tape.

[0076] Comparing the data of Example 1 and Comparative Example 2, it can be seen that in the absence of hydrotalcite, the dielectric strength, limiting oxygen index, and heat resistance of the cable core wrapping will decrease, but the flexural strength and tensile strength will increase. This is because in the absence of hydrotalcite, the flame retardancy will be greatly reduced, but will not be lower than the limit of polyester, and the tensile strength will be improved.

[0077] Comparing the data of Example 1 and Comparative Example 3, it can be seen that when carboxymethyl cellulose and hydrotalcite are mixed by ordinary stirring, the limiting oxygen index and tensile strength of the cable core wrapping decrease slightly. This is because when mixed by ordinary stirring, carboxymethyl cellulose cannot be evenly dispersed in the hydrotalcite powder, which also reduces the probability of it adhering to the hydrotalcite, and the bridging effect of carboxymethyl cellulose will be reduced.

[0078] Comparing the data of Example 1 and Comparative Example 4, it can be seen that all the indicators of the cable core wrapping will decrease when aramid precipitated fibers are not used. This is because the paper uniformity will decrease after the lack of aramid precipitated fibers, and the hydrotalcite cannot be retained.

[0079] The preferred embodiments of the present invention have been described in detail above with reference to the examples. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0080] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0081] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing a flame-retardant polyester fiber paper-based cable core wrapping tape, characterized in that, Includes the following steps: S1. Grind and mix hydrotalcite and carboxymethyl cellulose for more than 20 minutes to obtain flame retardant filler. In the flame retardant filler, the mass percentage of hydrotalcite is 95-98% and the mass percentage of carboxymethyl cellulose is 2-5%. S2. The polyester fiber, the aramid precipitated fiber and the flame retardant filler obtained in step S1 are mixed and formulated into a slurry, wherein the mass ratio of the polyester fiber, the aramid precipitated fiber and the flame retardant filler is (20~30):(40~50):(20~60). S3. Disperse the pulp obtained in step S2 in water, then loosen it, and dehydrate and form it on a paper forming machine to obtain a wet paper web. S4. After drying and hot pressing the wet paper web obtained in step S3, flame-retardant polyester fiber paper-based cable core wrapping tape is obtained.

2. The preparation method according to claim 1, characterized in that, In step S2, the linear density of the polyester fiber is 60~100 dtex and the length is 4~6 mm.

3. The preparation method according to claim 1, characterized in that, In step S3, the rotation speed is reduced to 18,000-20,000 revolutions.

4. The preparation method according to any one of claims 1 to 3, characterized in that, In step S4, the drying temperature is 110~120℃, the vacuum degree is 8~12Mpa, and the time is 10~15min.

5. The preparation method according to any one of claims 1 to 3, characterized in that, In step S4, the hot pressing temperature is 180~190℃, the pressure is 8~10 MPa, and the time is 4~8 min.

6. A flame-retardant polyester fiber paper-based cable core wrapping tape, characterized in that, It is prepared by any one of claims 1 to 5.

7. The flame-retardant polyester fiber paper-based cable core wrapping tape according to claim 6, characterized in that, The weight of the flame-retardant polyester fiber paper-based cable core wrapping tape is 60~80g.

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