Halogen-free flame-retardant packing belt and preparation method thereof

Abstract

The application discloses a kind of halogen-free flame-retardant packing belt and preparation method thereof.The preparation method of the halogen-free flame-retardant packing belt includes S1, polypropylene, additive, halogen-free composite flame retardant, functional agent, reinforcing agent are mixed, and mixed material is obtained;S2, mixed material is poured into the inner cavity of screw extruder through hopper, and the heating temperature is 180-220 DEG C;S3, the material in step S2 is taken out of extrusion die, enters water cooling, and the cooling water temperature is controlled at 38-42 DEG C;S4, the material cooled in step S3 is first stretched once, then water cooling is shaped, and then secondary stretching is carried out, and then water cooling is shaped;S5, the packing belt shaped in step S4 is passed through two patterned compression rollers, is pressed on pattern, is cooled and shaped after being pressed on pattern, is wound, is detected, is packaged, and is stored in warehouse.Compared with prior art, the packing belt prepared by the application has good flame-retardant effect, good mechanical effect and other advantages.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of packing tape materials, and particularly relates to a halogen-free flame-retardant packing tape and a preparation method thereof. BACKGROUND

[0002] PP packing tape, also known as polypropylene packing tape, has good plasticity, strong tensile strength, light weight, and other advantages, and is widely used in various fields.

[0003] However, ordinary PP packing tape is easy to be oxidized, has no flame-retardant and fireproof properties, has a high skew rate, and has poor actual use effect, and is also prone to problems such as static electricity, poor anti-deformation performance, and short service life.

[0004] CN112143096A discloses a light PP packing tape and a forming processing method thereof, and the use performance of the packing tape is improved by adding polypropylene, a filler, a colorant, and an anti-aging agent. However, the PP packing tape prepared by the method does not have the properties of flame retardation and fireproofing.

[0005] CN111138762A discloses a preparation method of a PP packing tape, and the fireproofing and flame-retardant properties are improved by adding polypropylene, polyethylene terephthalate, dibutyl hydroxytoluene, a toughening agent, and a flame retardant. However, the PP packing tape prepared by the method may have poor mechanical effect. SUMMARY

[0006] In view of the above defects of the prior art, the purpose of the present application is to provide a halogen-free flame-retardant packing tape, which has the characteristics of good flame-retardant and fireproofing effect, high crystallinity, low skew rate, and good mechanical effect.

[0007] One of the purposes of the present application is to provide a halogen-free flame-retardant packing tape, which comprises the following raw materials: 100-120 parts by weight of polypropylene, 1-6 parts by weight of an additive, 200-250 parts by weight of a halogen-free composite flame retardant, 5-10 parts by weight of a functional agent, and 5-10 parts by weight of a reinforcing agent.

[0008] Preferably, the additive is selected from one of montmorillonite and modified montmorillonite.

[0009] Further preferably, the preparation method of the modified montmorillonite comprises the following steps, by weight:

[0010] Take 10-20 parts of dodecyl dimethyl benzyl ammonium bromide into 100-200 parts of water, stirring at 800-1000 rpm, heating to 80-100℃, adding 50-100 parts of montmorillonite, continue stirring for 2-4h; cooling, then centrifuging at 2000-4000 rpm for 5-10 min, precipitate is washed with water for 3-6 times, drying at 60-80℃ for 6-8h, crushing through 100-200 mesh sieve, to obtain modified montmorillonite.

[0011] As a further illustration of the present application, dodecyl dimethyl benzyl ammonium bromide as a modifier can be inserted into the interlayer structure of montmorillonite to obtain modified montmorillonite. The packing tape prepared by compounding the modified montmorillonite with polypropylene and other materials can form a stress transfer network, which is conducive to improving its impact resistance and tensile capacity. At the same time, the layered structure of the modified montmorillonite can isolate the penetration of gas and water molecules, and can improve the thermal stability and barrier properties of the composite material.

[0012] Preferably, the preparation method of the halogen-free composite flame retardant comprises the following steps, by weight parts:

[0013] (1) 10-20 parts of phytic acid is added to 100-200 parts of water, mixed and stirred at room temperature and 800-1000 rpm to obtain solution A; 10-20 parts of 1-phenylpiperazine is added to 100-200 parts of water, mixed and stirred at room temperature and 800-1000 rpm to obtain solution B;

[0014] (2) Solution A is heated to 80-100℃ and stirred at 800-1000 rpm for 10-20 min, and solution B is added to solution A in 2-4 times within 20-30 min, and then reacted for 20-40 min; after filtration, the filter cake is washed with 50-70℃ water for 4-6 times, and dried at 70-90℃ for 16-24h to obtain solid C;

[0015] (3) 5-15 parts of solid C is mixed and stirred uniformly with 5-10 parts of polyether amine, 10-15 parts of dimethylthio toluene diamine and 10-15 parts of 4,4'-methylene bis[N-sec-butyl aniline] at 30-50℃; then 20-30 parts of polypropylene glycol and 20-40 parts of isophorone diisocyanate are added and continue to mix and stir to obtain a halogen-free composite flame retardant.

[0016] As a further illustration of the present application, the halogen-free composite flame retardant can absorb the heat of the baling twine substrate surface, pyrolysis to release NH3 and H2O and other non-combustible gas, which can dilute the surrounding oxygen concentration, and has a certain extinguishing effect on the flame; on the other hand, the generated non-combustible gas NH3 can consume active free radicals in the gas phase, inhibit the combustion process. In the case of continuous temperature rise, the halogen-free composite flame retardant can absorb heat to generate acidic substances such as phosphoric acid and polyphosphoric acid, which can esterify with 1-phenylpiperazine. The esterification process will generate NH3 and H2O and other non-combustible gases to make the system in a molten state expand and foam. When the reaction is close to completion, the system solidifies, and finally forms a dense expanded carbon layer. The expanded carbon layer can effectively inhibit the material and energy transfer process between the combustion layer and the baling twine, and hinder the pyrolysis of the underlying material.

[0017] Preferably, the functional agent is selected from one of nano-zinc oxide, modified nano-zinc oxide.

[0018] Further preferably, the preparation method of the modified nano-zinc oxide comprises the following steps, in terms of weight parts:

[0019] Mix 5-10 parts of ethyl glycolate and 10-20 parts of a modifier uniformly, then add 0.1-1 parts of dibutyltin dilaurate, and then heat to 30-50°C, stir at 800-1000 rpm for 3-5 h to obtain a mixed solution D; mix 10-20 parts of the mixed solution D, 1-5 parts of nano-zinc oxide, 80-100 parts of anhydrous ethanol, and 40-50 parts of water, and then ultrasonic dispersion at 40-60 kHz for 0.5-1.5 h, and then add 20-40 wt% NaOH aqueous solution to adjust the pH to 9-11 to obtain a mixed solution E; stir the mixed solution E at 50-70°C, 800-1000 rpm for 10-14 h, and then perform suction filtration, wash the precipitate with anhydrous ethanol 4-6 times, and then wash with water 4-6 times, and then dry at 60-80°C for 6-8 h to obtain the modified nano-zinc oxide.

[0020] Preferably, the modifier is selected from at least one of methyl acryloyl propyl tri (trimethyl siloxane) silane, isocyanic acid propyl triethoxy silane, and pentafluorophenyl triethoxy silane.

[0021] As a further illustration of the present application, the aging process of PP packing tape is mainly that the external environment causes the generation of active free radicals, and the free radicals continuously initiate chain reactions in the oxygen environment, thereby breaking the polypropylene molecular chain and ultimately leading to degradation. The present application introduces modified nano zinc oxide mixed with polypropylene to prepare a halogen-free flame-retardant packing tape. The modified nano zinc oxide has a high ultraviolet absorption rate, which can protect against ultraviolet damage. At the same time, the modified nano zinc oxide can slow down the chain reaction by capturing free radicals, thereby reducing the aging rate of polypropylene. In addition, the modified nano zinc oxide can also act as a nucleating agent, which can improve the crystallinity of the packing tape and promote the tensile strength, dimensional stability and temperature resistance of the packing tape.

[0022] Preferably, the reinforcing agent is continuous CF / PEEK prepreg powder; and the preparation method of the continuous CF / PEEK prepreg powder comprises the following steps: crushing 10-20 parts of continuous CF / PEEK prepreg powder through a 100-200 mesh sieve to obtain continuous CF / PEEK prepreg powder.

[0023] As a further illustration of the present application, the continuous CF / PEEK prepreg powder has the advantages of lightweight, high strength, corrosion resistance, aging resistance, high temperature resistance, etc. The addition of continuous CF / PEEK prepreg powder can improve the mechanical properties and temperature resistance of the packing tape, and also induce crystallization, improve the crystallinity of the packing, and improve the dimensional stability.

[0024] The second object of the present application is to provide a preparation method of the above-mentioned halogen-free flame-retardant packing tape, which comprises the following steps:

[0025] S1, mixing polypropylene, additives, halogen-free composite flame retardant, functional agent and reinforcing agent to obtain a mixture;

[0026] S2, pouring the mixture into the inner cavity of the screw extruder through the hopper, and heating the temperature to 180-220 DEG C to obtain a material;

[0027] S3, taking out the material in step S2 from the extrusion die, and cooling in water, with the cooling water temperature controlled at 38-42 DEG C, to obtain a cooled material;

[0028] S4, first stretching the cooled material in step S3 and then water-cooling and setting, and then second stretching and water-cooling and setting, to obtain a set packing tape;

[0029] S5, passing the set packing tape in step S4 through two patterned compression rollers, pressing the patterns, and then cooling and setting, winding, detecting, packaging and warehousing, to obtain a halogen-free flame-retardant packing tape.

[0030] The present application has the following advantages:

[0031] 1. The packing tape prepared by the inventors using the formula materials and methods provided in this invention has high uniformity in thickness and width, and very low skewness.

[0032] 2. Compared with the prior art, the packing tape prepared by adding modified montmorillonite, halogen-free composite flame retardant, modified nano zinc oxide, and continuous CF / PEEK prepreg powder has good flame retardant and fireproof effect, high crystallinity, low skewness, and good mechanical properties. Attached Figure Description

[0033] Appendix Figure 1 This is a product image. Detailed Implementation

[0034] The parameters and sources of some raw materials in this embodiment of the invention are as follows:

[0035] Polypropylene, grade: P740J, brand: Siam, Thailand;

[0036] Montmorillonite, specific surface area 240m² 2 / g;

[0037] Nano zinc oxide, particle size: 50±10nm;

[0038] Polyetheramine, product number: P939193, MW~2000, EO / PO ratio: 6 / 29, sourced from Shanghai Maclean Biochemical Technology Co., Ltd.;

[0039] 1-Phenylopiraine, CAS No.: 92-54-6;

[0040] Polypropylene glycol, average molecular weight 4000;

[0041] Continuous CF / PEEK prepreg, material grade: LU-CF / PEEK, carbon fiber content: 66%, sourced from Jiangsu Junhua Special Polymer Materials Co., Ltd. CF refers to carbon fiber, and PEEK refers to polyetheretherketone.

[0042] Example 1

[0043] A method for preparing halogen-free flame-retardant packing straps includes the following steps:

[0044] S1. Mix 110g of polypropylene, 4g of modified montmorillonite, 230g of halogen-free composite flame retardant, 8g of modified nano zinc oxide, and 8g of continuous CF / PEEK prepreg powder to obtain a mixture.

[0045] S2. Pour the mixture into the inner cavity of the screw extruder through the hopper and heat it to 200℃;

[0046] S3. Carry the material from step S2 out of the extrusion die and into water for cooling. The cooling water temperature is controlled at 40℃.

[0047] S4, the material cooled in step S3 is first stretched and then water-cooled and shaped, and then stretched again and then water-cooled and shaped;

[0048] S5, the shaped packing belt in step S4 is pressed by two patterned rollers, and then cooled and shaped, wound, detected, packaged and stored.

[0049] The modified montmorillonite is prepared by the following method:

[0050] 15g of dodecyl dimethyl benzyl ammonium bromide is weighed into 150g of water, heated to 90℃ with stirring at 900rpm, then 80g of montmorillonite is added, and stirring and heating is continued for 3h; after cooling, centrifugation is carried out at 3000rpm for 8min, the precipitate is washed with water for 5 times, dried at 70℃ for 7h, and then crushed through a 200 mesh sieve to obtain the modified montmorillonite.

[0051] The halogen-free composite flame retardant is prepared by the following steps:

[0052] (1) 15g of phytic acid is added to 150g of water, and mixed and stirred at room temperature at 900rpm to obtain solution A; 15g of 1-phenylpiperazine is added to 150g of water, and mixed and stirred at room temperature at 900rpm to obtain solution B;

[0053] (2) solution A is heated to 90℃, and stirred at 900rpm for 10min, and solution B is added to solution A in three times within 25min, and then reacted for 30min; after filtration, the filter cake is washed with 60℃ water for 5 times, and dried at 80℃ for 20h to obtain solid C;

[0054] (3) 10g of solid C is mixed with 7g of polyether amine, 12g of dimethylthio toluene diamine, and 13g of 4,4'-methylene bis[N-sec-butyl aniline] at 40℃; then 25g of polypropylene glycol and 25g of isophorone diisocyanate are added, and mixed and stirred to obtain the halogen-free composite flame retardant.

[0055] The modified nano zinc oxide is prepared by the following method:

[0056] Mix 7.5 g of ethyl glycolate and 15 g of pentafluorophenyl triethoxysilane uniformly, and after adding 0.5 g of dibutyl tin dilaurate, heat to 40℃, stir at 900 rpm for 4 h to obtain a mixed solution D; mix 15 g of the mixed solution D, 3 g of nano zinc oxide (particle size: 50±10 nm), 90 g of anhydrous ethanol, and 45 g of water, and ultrasonically disperse at 50 kHz for 1.0 h, add 30 wt% NaOH aqueous solution to adjust the pH to 10 to obtain a mixed solution E; stir the mixed solution E at 60℃ for 12 h at 900 rpm, suction filter, wash the precipitate with anhydrous ethanol for 5 times, wash with water for 5 times, and dry at 70℃ for 7 h to obtain modified nano zinc oxide.

[0057] The continuous CF / PEEK prepreg powder is prepared by the following method:

[0058] The 15 g of the continuous CF / PEEK prepreg is crushed through a 200 mesh sieve to obtain the continuous CF / PEEK prepreg powder.

[0059] Example 2

[0060] A method for preparing a halogen-free flame-retardant packing belt, which is different from example 1 in that 4 g of modified montmorillonite in step S1 is replaced by 4 g of montmorillonite.

[0061] Example 3

[0062] A method for preparing a halogen-free flame-retardant packing belt, which is different from example 1 in that the 230 g of halogen-free composite flame retardant in step S1 is replaced by 230 g of halogen-free composite flame retardant prepared by the following method.

[0063] The halogen-free composite flame retardant is prepared by the following steps:

[0064] Mix 10 g of triphenyl phosphate with 7 g of polyetheramine, 12 g of dimethylthio toluene diamine, and 13 g of 4,4'-methylene bis[N-sec-butyl aniline] uniformly at 40℃; then add 25 g of polypropylene glycol and 25 g of isophorone diisocyanate to obtain a halogen-free composite flame retardant.

[0065] Example 4

[0066] A method for preparing a halogen-free flame-retardant packing belt, which is different from example 1 in that the modified nano zinc oxide in step S1 is prepared by the following method:

[0067] Mixing 7.5 g of ethyl glycolate and 15 g of propyl triethoxysilane isocyanate uniformly, after adding 0.5 g of dibutyl tin dilaurate, the temperature is raised to 40℃, 900 rpm stirring for 4 h, to obtain a mixed solution D; mixing 15 g of mixed solution D, 3 g of nano zinc oxide (particle size: 50±10 nm), 90 g of anhydrous ethanol, 45 g of water, ultrasonic dispersion at 50 kHz for 1.0 h, adding 30 wt% NaOH aqueous solution to adjust the pH to 10, to obtain a mixed solution E; the mixed solution E is stirred at 60℃, 900 rpm for 12 h, suction filtration, the precipitate is washed with anhydrous ethanol for 5 times, water for 5 times, dried at 70℃ for 7 h, to obtain modified nano zinc oxide.

[0068] Example 5

[0069] A method for preparing a halogen-free flame-retardant packing tape, which is different from example 1 in that the modified nano zinc oxide in step S1 is prepared by the following method:

[0070] Mixing 7.5 g of ethyl glycolate and 15 g of methacryloyloxypropyl tri(trimethylsiloxy)silane isocyanate uniformly, after adding 0.5 g of dibutyl tin dilaurate, the temperature is raised to 40℃, 900 rpm stirring for 4 h, to obtain a mixed solution D; mixing 15 g of mixed solution D, 3 g of nano zinc oxide (particle size: 50±10 nm), 90 g of anhydrous ethanol, 45 g of water, ultrasonic dispersion at 50 kHz for 1.0 h, adding 30 wt% NaOH aqueous solution to adjust the pH to 10, to obtain a mixed solution E; the mixed solution E is stirred at 60℃, 900 rpm for 12 h, suction filtration, the precipitate is washed with anhydrous ethanol for 5 times, water for 5 times, dried at 70℃ for 7 h, to obtain modified nano zinc oxide.

[0071] Comparative example 1

[0072] A method for preparing a halogen-free flame-retardant packing tape, which is different from example 1 in that the 230 g of halogen-free composite flame retardant in step S1 is replaced by a mixture of 10 g of triphenyl phosphate and 220 g of polypropylene.

[0073] Test example 1

[0074] Performance test

[0075] The packing tapes of examples 1-5 and comparative example 1 have a width of 12 mm and a thickness of 0.6 mm. The performance of each example and comparative example is tested.

[0076] Test method:

[0077] 1. According to the method of QB / T 3811-1999 plastic packing tape, the skew rate is measured.

[0078] 2. According to the method of GB / T32340-2015 Cotton Packaging Polyester Strapping Band, test the longitudinal cracking property, the cracking point number n / 10, the smaller the n value, the better the performance of the strapping band.

[0079] 3. According to GB / T2408-2021 Determination of the Burning Behavior of Plastics by the Horizontal and Vertical Method, conduct vertical burning experiment to determine the flame retardant grade; Xenon lamp aging method: after 1200h xenon lamp aging test at 420nm wavelength according to GB / T16422.2-2022 Laboratory Light Source Exposure Test Method for Plastics, conduct vertical burning experiment again according to GB / T2408-2008 Determination of the Burning Behavior of Plastics by the Horizontal and Vertical Method.

[0080] The test results are shown in Table 1 below.

[0081] Table 1

[0082]

[0083]

[0084] Through the comparison of Examples 1-5 and Comparative Example 1, it can be found that the width deviation, thickness deviation and skew rate of Example 1 are the lowest. The possible reason is that the material used in Example 1 is of stable quality, the material liquid obtained is uniform, and the size of the strapping band obtained by using the material combination and preparation process is more stable, so the skew rate is lower.

[0085] Through the comparison of Examples 1-5 and Comparative Example 1, it can be found that the longitudinal cracking property of Example 1 is low. The possible reason is that the strapping band prepared by compounding the modified montmorillonite with polypropylene and other materials in Example 1 can form a stress transfer network to improve its impact resistance and tensile strength, and the mechanical effect is improved; the added halogen-free composite flame retardant not only has flame retardant effect, but also has high tensile strength and tear strength due to its polyurea structure, which improves the mechanical effect of the strapping band; modified nano zinc oxide and continuous CF / PEEK prepreg powder can act as a heterogeneous nucleating agent to induce crystallization, and the crystalline region acts as a physical crosslinking point to enhance the interaction between molecules and enhance the tensile strength, thereby improving the mechanical effect.

[0086] By comparing examples 1-5, it can be found that the flame retardant grade of example 1 is higher after light aging, and the possible reason is that the modified montmorillonite added in example 1 can isolate the penetration of gas and water molecules, improve the thermal stability and barrier performance of the composite material; the halogen-free composite flame retardant releases NH3 and H2O and other non-combustible gases during pyrolysis, which can dilute the surrounding oxygen concentration, and the system solidifies after pyrolysis, forming a dense expanded carbon layer that can effectively inhibit the material and energy transfer process between the combustion layer and the packing belt, and hinder the material pyrolysis; the effect of five-fluorophenyl triethoxysilane modified nano zinc oxide on absorbing ultraviolet and capturing free radicals is better, slowing down the chain reaction, thereby reducing the aging rate of the packing belt.

[0087] Test example 2

[0088] Crystallinity test

[0089] The packing belt samples prepared by examples 1-5 and comparative example 1 of the application were respectively subjected to DSC test, all experiments were carried out in nitrogen atmosphere, the sample mass was 5-8 mg, the heating and cooling rate was 10 K / min, the crystallinity of the test sample was tested, and the test results are shown in Table 2.

[0090] Table 2

[0091]

[0092] By comparing examples 1-5 and comparative example 1, it can be found that the crystallinity of example 1 is the highest, and the possible reason is that the modified montmorillonite added in example 1 can form a limited space, reduce the nucleation activation energy and improve the crystallinity; it may be that the surface activity of five-fluorophenyl triethoxysilane modified nano zinc oxide is higher, and the combination effect with polypropylene molecular chain is better, as a nucleating agent, it provides crystal nucleus for the crystallization of polypropylene molecular chain and promotes the crystallization effect more; the continuous CF / PEEK prepreg powder has a regular fiber structure, which can be used as a physical crosslinking point to enhance the interaction between molecules and promote the crystallization of polypropylene.

Claims

1. A halogen-free flame-retardant packing strap, characterized in that: The raw material components, by weight, include 100-120 parts of polypropylene, 1-6 parts of additives, 200-250 parts of halogen-free composite flame retardant, 5-10 parts of functional agent, and 5-10 parts of reinforcing agent. The additive is modified montmorillonite; The preparation method of the modified montmorillonite includes the following steps, in parts by weight: Weigh 10-20 parts of dodecyl dimethyl benzyl ammonium bromide and add it to 100-200 parts of water. Stir at 800-1000 rpm and heat to 80-100℃. Add 50-100 parts of montmorillonite and continue stirring for 2-4 hours. Cool and then centrifuge at 2000-4000 rpm for 5-10 minutes. Wash the precipitate with water 3-6 times, dry at 60-80℃ for 6-8 hours, and pulverize it through a 100-200 mesh sieve to obtain modified montmorillonite. The preparation method of the halogen-free composite flame retardant includes the following steps, in parts by weight: (1) Add 10-20 parts of phytic acid to 100-200 parts of water and mix and stir at room temperature and 800-1000 rpm to obtain solution A; add 10-20 parts of 1-phenylpiperazine to 100-200 parts of water and mix and stir at room temperature and 800-1000 rpm to obtain solution B; (2) Heat solution A to 80-100℃ and stir at 800-1000 rpm for 10-20 min. Add solution B to solution A in 2-4 portions, completing the addition within 20-30 min. Then react for 20-40 min. After that, filter the solution and wash the filter cake with water at 50-70℃ 4-6 times. Dry the filter cake at 70-90℃ for 16-24 h to obtain solid C. (3) Mix 5-15 parts of solid C with 5-10 parts of polyetheramine, 10-15 parts of dimethylthiotoluenediamine and 10-15 parts of 4,4'-methylenebis[N-sec-butylaniline] at 30-50℃ and stir evenly; then add 20-30 parts of polypropylene glycol and 20-40 parts of isophorone diisocyanate, and continue to mix and stir to obtain a halogen-free composite flame retardant; The functional agent is modified nano zinc oxide; The preparation method of the modified nano zinc oxide includes the following steps, in parts by weight: Mix 5-10 parts of ethyl glycolate and 10-20 parts of modifier evenly, then add 0.1-1 parts of dibutyltin dilaurate and heat to 30-50℃, stirring at 800-1000 rpm for 3-5 hours to obtain mixed solution D; mix 10-20 parts of mixed solution D, 1-5 parts of nano zinc oxide, 80-100 parts of anhydrous ethanol, and 40-50 parts of water, and ultrasonically disperse at 40-60 kHz for 0.5-1.5 hours, then add 20-40 wt% NaOH aqueous solution to adjust the pH to 9-11 to obtain mixed solution E; stir mixed solution E at 50-70℃ and 800-1000 rpm for 10-14 hours, filter, wash the precipitate 4-6 times with anhydrous ethanol, then wash 4-6 times with water, and then dry at 60-80℃ for 6-8 hours to obtain modified nano zinc oxide; The modifier is pentafluorophenyltriethoxysilane.

2. The halogen-free flame-retardant packing strap as described in claim 1, characterized in that, The reinforcing agent is a continuous CF / PEEK prepreg powder; the preparation method of the continuous CF / PEEK prepreg powder includes the following steps, in parts by weight: 10-20 parts of continuous CF / PEEK prepreg are crushed and passed through a 100-200 mesh sieve to obtain continuous CF / PEEK prepreg powder.

3. The method for preparing a halogen-free flame-retardant packing strap according to any one of claims 1-2, characterized in that, Includes the following steps: S1. Mix polypropylene, additives, halogen-free composite flame retardant, functional agent and reinforcing agent to obtain a mixture; S2. Pour the mixture through the hopper into the inner cavity of the screw extruder, and heat it to 180-220℃ to obtain the material; S3. The material from step S2 is carried out of the extrusion die and cooled in water. The cooling water temperature is controlled at 38-42℃ to obtain the cooled material. S4. The material cooled in step S3 is first stretched and then water-cooled and shaped, and then stretched and water-cooled and shaped again to obtain the shaped packing strap. S5. The shaped packing strap from step S4 is passed through two patterned pressure rollers to press the pattern onto the strapping. After cooling and shaping, the strapping is wound up, inspected, packaged, and stored to obtain halogen-free flame-retardant packing strapping.

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