A hyperbranched cyclodextrin finishing solution for environment-friendly flame-retardant PET braided sheath and a preparation method and application thereof

Abstract

The present application relates to surface modification and wire harness protection technical field, especially to a kind of hyperbranched cyclodextrin finishing liquid for environment-friendly flame-retardant PET braided sheath and its preparation method and application.A kind of hyperbranched cyclodextrin finishing liquid, the raw material of the hyperbranched cyclodextrin finishing liquid includes the following components by weight parts:67.0 portion~96.0 portion hyperbranched cyclodextrin aqueous solution, 1.0 portion~15.0 portion fatty acid polyester, 1.0 portion~10.0 portion polyethylene glycol ester, 1.0 portion~3.0 portion polyoxyethylene ether and 1.0 portion~10.0 portion polyglycerol fatty acid ester.

Description

Technical Field

[0001] This invention relates to the fields of surface modification and wire harness protection technology, and in particular to a hyperbranched cyclodextrin finishing liquid for environmentally friendly flame-retardant PET braided sheaths, its preparation method, and its application. Background Technology

[0002] With the rapid development of electrification, intelligentization, and connectivity in new energy vehicles, the air quality inside the car cabin, a closed space where passengers spend a significant amount of time, has become a core competitive factor for both OEMs and consumers. Braided sheaths are extensively used in the interior and mechanical structures of car cabins to protect critical components such as wiring harnesses and conduits. Polyethylene terephthalate (PET) has become the mainstream material for these braided sheaths due to its excellent mechanical properties, abrasion resistance, and flame retardancy. However, traditional PET materials, during processing, molding, and in the long-term heated environment of the car cabin, easily release extremely complex volatile organic compounds (TVOCs), including short-chain fatty acids, aldehydes, and ketones, accompanied by a strong, pungent odor. As environmental standards for interior trim and wiring harness components become increasingly stringent in the industry, environmental indicators have become a rigid threshold for suppliers to enter the supply chain. How to reduce VOC emissions from flame-retardant PET braided sheaths at the source and effectively control odor has become a critical problem that urgently needs to be solved in this field.

[0003] To improve the environmental performance of woven protective sleeves, the industry has explored various technological approaches, but all face significant limitations. The first approach is material substitution, using bio-based materials or recycled PET (rPET) and other environmentally friendly substrates. However, these materials are over 30% more expensive than traditional materials, and their mechanical properties, such as wear resistance and heat aging resistance, are inferior, hindering large-scale substitution. The second approach relies on physical deodorization processes, such as vacuum degassing and extraction-based VOC reduction processes. However, these processes not only have poor compatibility with existing production lines but also require extremely high investment in environmental protection equipment, which most companies cannot afford. The third approach involves introducing external odor control agents. For example, existing technologies disclose the use of mixed enzymes such as N-acetylcysteine-binding protease to destroy odor sources through biodegradation, or the use of conventional uncomplexed ordinary cyclodextrin aqueous solutions as sprays for physical adsorption. However, biological enzyme preparations have extremely poor temperature resistance and cannot adapt to the high-temperature processing and summer sun exposure environment of the automotive industry. Ordinary cyclodextrins have a limited number of hydrophobic cavities inside the molecule, resulting in a serious lack of capture capacity for complex TVOCs. Furthermore, ordinary small molecule materials are extremely difficult to stably adhere to the smooth PET fiber surface without strong cross-linking, and are prone to falling off and failing in the subsequent heat curing of textiles or in the actual use environment, making the odor control effect unsustainable.

[0004] In summary, existing VOC reduction and odor control technologies struggle to achieve a balance between capture efficiency, long-lasting adhesion, and industrial application costs. Therefore, there is a need in this field for an environmentally friendly surface finishing liquid formulation system specifically designed for PET textile substrates. This formulation system must be able to increase the odor molecule capture capacity to efficiently block TVOC emissions without sacrificing the original flame retardant and mechanical properties of the PET webbing. Simultaneously, this finishing liquid system must possess excellent emulsification, dispersion, and self-assembly film-forming capabilities to overcome the technical shortcomings of traditional physical adsorbents, such as poor adhesion to fiber surfaces and insufficient washability and heat aging resistance. This would enable the low-cost, large-scale application of long-lasting environmentally friendly odor removal functions to traditional PET sheaths without increasing investment in expensive equipment. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a hyperbranched cyclodextrin finishing liquid for environmentally friendly flame-retardant PET woven sheaths, its preparation method, and its application.

[0006] Firstly, a hyperbranched cyclodextrin finishing solution employs the following technical solution: A hyperbranched cyclodextrin finishing solution, wherein the raw materials of the hyperbranched cyclodextrin finishing solution, by weight, include the following components: 67.0 parts to 96.0 parts of a hyperbranched cyclodextrin aqueous solution, 1.0 parts to 15.0 parts of fatty acid polyester, 1.0 parts to 10.0 parts of polyethylene glycol ester, 1.0 parts to 3.0 parts of polyoxyethylene ether, and 1.0 parts to 10.0 parts of polyglycerol fatty acid ester.

[0007] Furthermore, the mass fraction of the hyperbranched cyclodextrin aqueous solution is 75%~85%; the hyperbranched cyclodextrin is a BETA-cyclodextrin-epoxychloropropane copolymer with a molecular weight of 3000~8000.

[0008] Furthermore, the skeletal alcohol component of the fatty acid polyester is selected from one or more of ethylene glycol-type polyester, polyethylene glycol-type polyester, propylene glycol-type polyester, polypropylene glycol-type polyester, glycerol-type polyester, polyglycerol-type polyester, neopentyl glycol-type polyester, or pentaerythritol-type polyester. The capping acid or ester component of the fatty acid polyester is selected from lauric acid or stearic acid.

[0009] Furthermore, the polyglycerol fatty acid ester is selected from one of polyglycerol-3-diisostearate, polyglycerol-4-didecanoate, or polyglycerol-6-didecanoate.

[0010] Secondly, a method for preparing a hyperbranched cyclodextrin finishing solution adopts the following technical solution: A method for preparing a hyperbranched cyclodextrin finishing solution includes the following specific steps: Step (1): The hyperbranched cyclodextrin aqueous solution is stirred at a speed of 200 rpm to 300 rpm and slowly heated to 60°C to 70°C; Step (2): Maintain the temperature at 60℃~70℃, increase the stirring speed to 3000rpm~4000rpm, and homogenize the hyperbranched cyclodextrin aqueous solution for 5min~10min; Step (3): Keep the temperature at 60℃~70℃, and add the polyoxyethylene ether, fatty acid polyester and polyethylene glycol ester dropwise at a uniform rate, controlling the addition time to 5min~15min, so that the added materials are fully dispersed by the main liquid; Step (4): Keep the temperature at 60℃~70℃, add the polyglycerol fatty acid ester dropwise at a uniform rate, control the addition time to 15min~30min, and increase the stirring speed to 5000 rpm~7000 rpm, and keep stirring at high speed for 20min~40min; Step (5): After all raw material components are fully dispersed, stop heating and reduce the rotation speed to 200 rpm to 300 rpm for maturation. After cooling to room temperature, filter to obtain the hyperbranched cyclodextrin finishing solution.

[0011] Thirdly, an environmentally friendly flame-retardant PET woven sheath adopts the following technical solution: An environmentally friendly flame-retardant PET woven sheath includes a PET webbing and a finishing layer attached to the surface of the PET webbing. The finishing layer is formed by curing a hyperbranched cyclodextrin finishing liquid as described in any one of claims 1 to 4. In the finishing layer, the hyperbranched cyclodextrin, the fatty acid polyester, and the polyglycerol fatty acid ester self-assemble to form a core-shell structure through hydrophobic interactions.

[0012] Furthermore, the actual oil content of the environmentally friendly flame-retardant PET woven sheath is 0.1%~2.0%.

[0013] Fourthly, a method for preparing an environmentally friendly flame-retardant PET woven sheath adopts the following technical solution: A method for preparing an environmentally friendly flame-retardant PET woven sheath includes the following specific steps: Step (1): Mix the hyperbranched cyclodextrin finishing solution with water to prepare a padding solution; Step (2): The padding solution is coated onto the surface of the PET webbing using a coating or padding method. The immersion time of the PET webbing in the padding solution is 0.1 min to 5.0 min, the padding time is 0.1 min to 5.0 min, and the liquid retention rate is 60% to 80%. Step (3) involves pre-baking and heat curing the coated PET webbing from step (2) in sequence; wherein the pre-baking temperature is 90℃~120℃ and the pre-baking time is 1min~2min; the heat curing temperature is 120℃~180℃ and the heat curing time is 1min~5min. Step (4) involves winding and shaping the PET webbing after heat curing in step (3) to obtain the environmentally friendly flame-retardant PET woven sheath.

[0014] Further, in step (1), the padding liquid comprises the following components in 100 parts by weight: 1 to 10 parts of hyperbranched cyclodextrin finishing liquid and 90 to 99 parts of water.

[0015] Fifthly, the application of an environmentally friendly flame-retardant PET woven sheath adopts the following technical solution: Application of an environmentally friendly flame-retardant PET woven sheath in automotive cabin interiors, wiring harnesses, or pipe outer layer protection.

[0016] The beneficial effects of this invention are: This invention provides a hyperbranched cyclodextrin finishing solution, which achieves efficient and long-lasting blocking of volatile organic compounds (VOCs) from flame-retardant PET woven sheaths through chemical synergy and microscopic self-assembly mechanisms of its components. The hyperbranched cyclodextrin, as the core adsorbent in the formulation, possesses a three-dimensional spherical network and extremely high functional group density, breaking the physical limitations of ordinary linear cyclodextrin in terms of the number of cavities. The numerous hydrophobic cavities it provides act as "molecular capsules," firmly capturing and locking small odor molecules such as short-chain fatty acids, aldehydes, and ketones released upon heating within the cavities through van der Waals forces and other interactions, thereby exponentially increasing the loading capacity and removal efficiency for complex odor molecules. Furthermore, this formulation combines hyperbranched cyclodextrin with bio-based flexible frameworks such as fatty acid polyesters and polyglycerol fatty acid esters. Under the synergistic emulsification of polyethylene glycol esters and polyoxyethylene ethers, the components not only achieve highly uniform dispersion but, more importantly, can self-assemble on the smooth PET fiber surface through hydrophobic interactions to form a stable "core-shell structure." This microscopic self-assembled cross-linked network greatly enhances the interfacial adhesion between the finishing layer and the PET substrate, giving the coating excellent wash resistance and high-temperature aging resistance. Therefore, this finishing solution can persistently exert its odor-removing effect under the harsh high-temperature and sun-exposed environment of automotive cabins. Furthermore, the system has excellent process adaptability, eliminating the need for expensive VOC reduction hardware such as vacuum extraction, thus controlling production costs while endowing traditional PET sheaths with high-value environmentally friendly attributes for large-scale production. Detailed Implementation

[0017] The following, in conjunction with embodiments, further describes in detail the hyperbranched cyclodextrin finishing liquid for environmentally friendly flame-retardant PET woven sheaths, its preparation method, and its application. For the sake of simplicity, this document cannot exhaustively list all alternative technical features and embodiments included in this invention. Therefore, those skilled in the art should understand that any technical feature and embodiment within this embodiment does not limit the scope of protection of this invention. The scope of protection includes all alternative technical features and embodiments adopted by those skilled in the art without creative effort. Specifically, any embodiment obtained by replacing any technical feature in this invention or by combining any two or more technical features provided by this invention should be within the scope of protection of this invention. Where specific techniques and conditions are not specified in the embodiments, they are performed according to the techniques and conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0018] Example Example 1 Example 1 provides a hyperbranched cyclodextrin finishing solution, comprising the following components: 84.0 kg of hyperbranched cyclodextrin aqueous solution (concentration of 80%); 5.0 kg of fatty acid polyester, specifically polyethylene glycol laurate (i.e., using polyethylene glycol-type polyester as the backbone alcohol component and lauric acid as the end-capping acid component); 5.0 kg of polyethylene glycol ester; 1.0 kg of polyoxyethylene ether; and 5.0 kg of polyglycerol fatty acid ester, specifically polyglycerol-3-diisostearate.

[0019] The hyperbranched cyclodextrin is a BETA-cyclodextrin-epoxychloropropane copolymer with a purity ≥95%, a heavy metal content ≤10 ppm, and a molecular weight of 5000.

[0020] This embodiment 1 also provides a method for preparing a hyperbranched cyclodextrin finishing solution, comprising the following steps: Step (1), Weighing and Gentle Stirring: Add the hyperbranched cyclodextrin aqueous solution to the stirred tank, gently stir with magnetic force at a speed of 250 rpm, and slowly heat to 65 ℃; Step (2), homogenization: Keep the temperature at 65 ℃, increase the stirring speed to 3500 rpm, and homogenize the hyperbranched cyclodextrin aqueous solution for 6 min; Step (3), first stage of addition: keep the temperature at 65 ℃, control the addition time to 10 min, add polyoxyethylene ether, polyethylene glycol laurate and polyethylene glycol ester in a thin and uniform flow to ensure that the added materials can be immediately dispersed by the main liquid and avoid local accumulation; Step (4), second stage of addition and high-speed dispersion: keep the temperature at 65 ℃, control the addition time to 20 min, add polyglycerol-3-diisostearate at a slower and uniform speed, and further increase the stirring speed to 6000 rpm. After all additives are added, keep stirring at high speed for 30 min. Step (5), low-speed maturation and filtration: After all raw material components are fully dispersed, heating is stopped and the speed is adjusted to 250 rpm for low-speed maturation. After cooling to room temperature, the mixture is filtered using a 300-mesh filter to remove impurities or gel particles, thus obtaining the hyperbranched cyclodextrin finishing solution.

[0021] This embodiment 1 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, including the following steps: Step (1), Solution preparation: Mix the hyperbranched cyclodextrin finishing solution prepared above with water. By weight, take 5 kg of the hyperbranched cyclodextrin finishing solution and dilute it with 95 kg of water to prepare a padding solution with a mass fraction of 5% of the hyperbranched cyclodextrin finishing solution. Pour the padding solution into the liquid tank. Step (2), Coating: Prepare flame-retardant PET webbing that has been rinsed with clean water. Using a coating / pad-dip method, apply the padding solution to the surface of the flame-retardant PET webbing. Control the immersion time of the flame-retardant PET webbing in the padding solution to 2.0 min, the padding time to 1.0 min, and control the liquid residue ratio (patch-up ratio) to 70%. Step (3), pre-baking and heat curing: The coated flame-retardant PET webbing is transferred to an oven for pre-baking and heat curing in sequence. The pre-baking temperature is controlled at 110 ℃, and the pre-baking time is 1.5 min; the heat curing temperature is controlled at 130 ℃, and the heat curing time is 2.0 min. During the heat curing film formation process, the hyperbranched cyclodextrin, the fatty acid polyester, and the polyglycerol fatty acid ester self-assemble on the webbing surface through hydrophobic interactions to form a stable core-shell structure finishing layer. Step (4), winding and shaping: After heat curing, the webbing is conveyed to a self-winding device for winding and shaping, thus obtaining the environmentally friendly flame-retardant PET woven sheath. Testing showed that the actual oil content of the finished environmentally friendly flame-retardant PET woven sheath was 1.0%.

[0022] Example 2 Example 2 provides a hyperbranched cyclodextrin finishing solution, comprising the following components: 67.0 kg of hyperbranched cyclodextrin aqueous solution (concentration of 85%); 15.0 kg of fatty acid polyester, specifically polypropylene glycol stearate (i.e., using polypropylene glycol-type polyester as the backbone alcohol component and stearic acid as the end-capping acid component); 10.0 kg of polyethylene glycol ester; 3.0 kg of polyoxyethylene ether; and 10.0 kg of polyglycerol fatty acid ester, specifically polyglycerol-4-didecanoate.

[0023] The hyperbranched cyclodextrin is a BETA-cyclodextrin-epoxychloropropane copolymer with a purity ≥95%, a heavy metal content ≤10 ppm, and a molecular weight of 8000.

[0024] This embodiment 2 also provides a method for preparing a hyperbranched cyclodextrin finishing solution, including the following steps: Step (1), Weighing and Gentle Stirring: Add the hyperbranched cyclodextrin aqueous solution to the stirred tank, gently stir with magnetic force at a speed of 200 rpm, and slowly heat to 60 ℃; Step (2), homogenization: Keep the temperature at 60 ℃, increase the stirring speed to 3000 rpm, and homogenize the hyperbranched cyclodextrin aqueous solution for 5 min; Step (3), first stage of addition: keep the temperature at 60 ℃, control the addition time to 5 min, add polyoxyethylene ether, polypropylene glycol stearate and polyethylene glycol ester in a thin and uniform flow to ensure that the added materials can be immediately dispersed by the main liquid and avoid local accumulation; Step (4), second stage of addition and high-speed dispersion: keep the temperature at 60 ℃, control the addition time to 15 min, add polyglycerol-4-didecanoate at a slower and uniform speed, and further increase the stirring speed to 5000 rpm. After all additives are added, keep stirring at high speed for 20 min. Step (5), low-speed maturation and filtration: After all raw material components are fully dispersed, heating is stopped and the speed is adjusted to 200 rpm for low-speed maturation. After cooling to room temperature, the mixture is filtered using a 200-mesh filter to remove impurities or gel particles, thus obtaining the hyperbranched cyclodextrin finishing solution.

[0025] This embodiment 2 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, including the following steps: Step (1), Solution preparation: Mix the hyperbranched cyclodextrin finishing solution obtained above with water. By weight, take 10 kg of the hyperbranched cyclodextrin finishing solution and dilute it with 90 kg of water to prepare a padding solution with a mass fraction of 10% of the hyperbranched cyclodextrin finishing solution. Pour the padding solution into the liquid tank. Step (2), Coating: Prepare flame-retardant PET webbing that has been rinsed with clean water. Using a coating / pad-dip method, coat the surface of the flame-retardant PET webbing with the padding solution. Control the immersion time of the flame-retardant PET webbing in the padding solution to 5.0 min, the padding time to 5.0 min, and control the liquid retention rate (patch-up rate) to 80%. Step (3), Pre-baking and heat curing: The coated flame-retardant PET webbing is transferred to an oven for pre-baking and heat curing. The pre-baking temperature is controlled at 90 ℃ for 2.0 min; the heat curing temperature is controlled at 120 ℃ for 5.0 min. During the heat curing film formation process, the hyperbranched cyclodextrin, the fatty acid polyester, and the polyglycerol fatty acid ester self-assemble on the webbing surface through hydrophobic interactions to form a stable core-shell structure finishing layer. Step (4), winding and shaping: After heat curing, the webbing is conveyed to a self-winding device for winding and shaping, thus obtaining the environmentally friendly flame-retardant PET woven sheath. Testing showed that the actual oil content of the finished environmentally friendly flame-retardant PET woven sheath was 2.0%.

[0026] Example 3 This embodiment 3 provides a hyperbranched cyclodextrin finishing solution, comprising the following components: 96.0 kg of hyperbranched cyclodextrin aqueous solution (concentration of 75%); 1.0 kg of fatty acid polyester, specifically glycerol laurate (i.e., using glycerol-type polyester as the backbone alcohol component and lauric acid as the end-capping acid component); 1.0 kg of polyethylene glycol ester; 1.0 kg of polyoxyethylene ether; and 1.0 kg of polyglycerol fatty acid ester, specifically polyglycerol-6-didecanoate.

[0027] The hyperbranched cyclodextrin is a BETA-cyclodextrin-epoxychloropropane copolymer with a purity ≥95%, a heavy metal content ≤10 ppm, and a molecular weight of 3000.

[0028] This embodiment 3 also provides a method for preparing a hyperbranched cyclodextrin finishing solution, including the following steps: Step (1), Weighing and Gentle Stirring: Add the hyperbranched cyclodextrin aqueous solution to the stirred tank, gently stir with magnetic force at a speed of 300 rpm, and slowly heat to 70 ℃; Step (2), homogenization: Keep the temperature at 70 ℃, increase the stirring speed to 4000 rpm, and homogenize the hyperbranched cyclodextrin aqueous solution for 10 min; Step (3), first stage of addition: keep the temperature at 70 ℃, control the addition time to 15 min, add polyoxyethylene ether, glycerol laurate and polyethylene glycol ester in a thin and uniform flow to ensure that the added materials can be immediately dispersed by the main liquid and avoid local accumulation; Step (4), second stage of addition and high-speed dispersion: keep the temperature at 70 ℃, control the addition time to 30 min, add polyglycerol-6-didecanoate at a slower and uniform speed, and further increase the stirring speed to 7000 rpm. After all additives are added, keep stirring at high speed for 40 min. Step (5), low-speed maturation and filtration: After all raw material components are fully dispersed, heating is stopped and the speed is adjusted to 300 rpm for low-speed maturation. After cooling to room temperature, the mixture is filtered using a 400-mesh filter to remove impurities or gel particles, thus obtaining the hyperbranched cyclodextrin finishing solution.

[0029] This embodiment 3 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, including the following steps: Step (1), Solution preparation: Mix the hyperbranched cyclodextrin finishing solution prepared above with water. By weight, take 1 kg of the hyperbranched cyclodextrin finishing solution and dilute it with 99 kg of water to prepare a padding solution with a mass fraction of 1% of the hyperbranched cyclodextrin finishing solution. Pour the padding solution into the liquid tank. Step (2), Coating: Prepare flame-retardant PET webbing that has been washed with clean water. Using a coating / paddling method, coat the surface of the flame-retardant PET webbing with the padding solution, controlling the immersion time of the flame-retardant PET webbing in the padding solution to be 0.1 min, the padding time to be 0.1 min, and the liquid residue rate (patch-up rate) to be 60%. Step (3), pre-baking and heat curing: The coated flame-retardant PET webbing is transferred to an oven for pre-baking and heat curing. The pre-baking temperature is controlled at 120 ℃ for 1.0 min; the heat curing temperature is controlled at 180 ℃ for 1.0 min. During the heat curing film formation process, the hyperbranched cyclodextrin, the fatty acid polyester, and the polyglycerol fatty acid ester self-assemble on the webbing surface through hydrophobic interactions to form a stable core-shell structure finishing layer. Step (4), winding and shaping: After heat curing, the webbing is conveyed to a self-winding device for winding and shaping, thus obtaining the environmentally friendly flame-retardant PET woven sheath. Testing showed that the actual oil content of the finished environmentally friendly flame-retardant PET woven sheath was 0.1%.

[0030] Example 4 Example 4 provides a hyperbranched cyclodextrin finishing solution, comprising the following components: 83.0 kg of hyperbranched cyclodextrin aqueous solution (concentration of 80%); 5.0 kg of fatty acid polyester, specifically polyethylene glycol laurate; 5.0 kg of polyethylene glycol ester; 2.0 kg of polyoxyethylene ether; and 5.0 kg of polyglycerol fatty acid ester, specifically polyglycerol-3-diisostearate.

[0031] The hyperbranched cyclodextrin is a BETA-cyclodextrin-epoxychloropropane copolymer with a purity ≥95% and a heavy metal content ≤10 ppm.

[0032] This embodiment 4 also provides a method for preparing a hyperbranched cyclodextrin finishing solution, including the following steps: Step (1), Weighing and Gentle Stirring: Add the hyperbranched cyclodextrin aqueous solution to the stirred tank, gently stir with magnetic force at a speed of 250 rpm, and slowly heat to 65 ℃; Step (2), homogenization: Keep the temperature at 65 ℃, increase the stirring speed to 3500 rpm, and homogenize the hyperbranched cyclodextrin aqueous solution for 6 min; Step (3), first stage of addition: keep the temperature at 65 ℃, control the addition time to 10 min, add polyoxyethylene ether, polyethylene glycol laurate and polyethylene glycol ester in a thin and uniform flow to ensure that the added materials can be immediately dispersed by the main liquid and avoid local accumulation; Step (4), second stage of addition and high-speed dispersion: keep the temperature at 65 ℃, control the addition time to 20 min, add polyglycerol-3-diisostearate at a slower and uniform speed, and further increase the stirring speed to 6000 rpm. After all additives are added, keep stirring at high speed for 30 min. Step (5), low-speed maturation and filtration: After all raw material components are fully dispersed, heating is stopped and the speed is adjusted to 250 rpm for low-speed maturation. After cooling to room temperature, the mixture is filtered using a 300-mesh filter to remove impurities or gel particles, thus obtaining the hyperbranched cyclodextrin finishing solution.

[0033] This embodiment 4 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, including the following steps: Step (1), Solution preparation: Mix the hyperbranched cyclodextrin finishing solution prepared above with water. By weight, take 5 kg of the hyperbranched cyclodextrin finishing solution and dilute it with 95 kg of water to prepare a padding solution with a mass fraction of 5% of the hyperbranched cyclodextrin finishing solution. Pour the padding solution into the liquid tank. Step (2), Coating: Prepare flame-retardant PET webbing that has been rinsed with clean water. Using a coating / pad-dip method, apply the padding solution to the surface of the flame-retardant PET webbing. Control the immersion time of the flame-retardant PET webbing in the padding solution to 2.0 min, the padding time to 1.0 min, and control the liquid residue ratio (patch-up ratio) to 70%. Step (3), pre-baking and heat curing: The coated flame-retardant PET webbing is transferred to an oven for pre-baking and heat curing in sequence. The pre-baking temperature is controlled at 110 ℃, and the pre-baking time is 1.5 min; the heat curing temperature is controlled at 130 ℃, and the heat curing time is 2.0 min. During the heat curing film formation process, the hyperbranched cyclodextrin, the fatty acid polyester, and the polyglycerol fatty acid ester self-assemble on the webbing surface through hydrophobic interactions to form a stable core-shell structure finishing layer. Step (4), winding and shaping: After heat curing, the webbing is conveyed to a self-winding device for winding and shaping, thus obtaining the environmentally friendly flame-retardant PET woven sheath. Testing showed that the actual oil content of the finished environmentally friendly flame-retardant PET woven sheath was 1.1%.

[0034] Example 5 Example 5 provides a hyperbranched cyclodextrin finishing solution, comprising the following components: 81.5 kg of hyperbranched cyclodextrin aqueous solution (concentration of 80%); 7.0 kg of fatty acid polyester, specifically neopentyl glycol stearate; 5.0 kg of polyethylene glycol ester; 1.5 kg of polyoxyethylene ether; and 5.0 kg of polyglycerol fatty acid ester, specifically polyglycerol-4-didecanoate.

[0035] The hyperbranched cyclodextrin is a BETA-cyclodextrin-epoxychloropropane copolymer with a purity ≥95% and a heavy metal content ≤10 ppm.

[0036] This embodiment 5 also provides a method for preparing a hyperbranched cyclodextrin finishing solution, including the following steps: Step (1), Weighing and Gentle Stirring: Add the hyperbranched cyclodextrin aqueous solution to the stirred tank, gently stir with magnetic force at a speed of 220 rpm, and slowly heat to 62 ℃; Step (2), homogenization: Keep the temperature at 62 ℃, increase the stirring speed to 3200 rpm, and homogenize the hyperbranched cyclodextrin aqueous solution for 8 min; Step (3), first stage of addition: keep the temperature at 62 ℃, control the addition time to 12 min, add polyoxyethylene ether, neopentyl glycol stearate and polyethylene glycol ester in a thin and uniform flow to ensure that the added materials can be immediately dispersed by the main liquid and avoid local accumulation; Step (4), second stage of addition and high-speed dispersion: keep the temperature at 62 ℃, control the addition time to 25 min, add polyglycerol-4-didecanoate at a slower and uniform speed, and further increase the stirring speed to 5500 rpm. After all additives are added, keep stirring at high speed for 25 min. Step (5), low-speed maturation and filtration: After all raw material components are fully dispersed, heating is stopped and the rotation speed is changed to 220 rpm for low-speed maturation. After cooling to room temperature, the mixture is filtered using a 300-mesh filter to remove impurities or gel particles, thus obtaining the hyperbranched cyclodextrin finishing solution.

[0037] This embodiment 5 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, including the following steps: Step (1), Solution preparation: Mix the hyperbranched cyclodextrin finishing solution prepared above with water. Take 3 kg of the hyperbranched cyclodextrin finishing solution and dilute it with 97 kg of water by weight to prepare a padding solution with a mass fraction of 3% of the hyperbranched cyclodextrin finishing solution. Pour the padding solution into the liquid tank. Step (2), Coating: Prepare flame-retardant PET webbing that has been rinsed with clean water. Using a coating / paddling method, apply the padding solution to the surface of the flame-retardant PET webbing. Control the immersion time of the flame-retardant PET webbing in the padding solution to 1.0 min, the padding time to 2.0 min, and control the liquid retention rate (patch-up rate) to 65%. Step (3), pre-baking and heat curing: The coated flame-retardant PET webbing is transferred to an oven for pre-baking and heat curing. The pre-baking temperature is controlled at 100 ℃ for 1.8 min; the heat curing temperature is controlled at 140 ℃ for 4.0 min. During the heat curing film formation process, the hyperbranched cyclodextrin, the fatty acid polyester, and the polyglycerol fatty acid ester self-assemble on the webbing surface through hydrophobic interactions to form a stable core-shell structure finishing layer. Step (4), winding and shaping: After heat curing, the webbing is conveyed to a self-winding device for winding and shaping, thus obtaining the environmentally friendly flame-retardant PET woven sheath. Testing showed that the actual oil content of the finished environmentally friendly flame-retardant PET woven sheath was 0.8%.

[0038] Example 6 Example 6 provides a hyperbranched cyclodextrin finishing solution, comprising the following components: 78.5 kg of a hyperbranched cyclodextrin aqueous solution (concentration of 80%); 10.0 kg of fatty acid polyester, specifically pentaerythritol laurate; 5.0 kg of polyethylene glycol ester; 1.5 kg of polyoxyethylene ether; and 5.0 kg of polyglycerol fatty acid ester, specifically polyglycerol-3-diisostearate.

[0039] The hyperbranched cyclodextrin is a BETA-cyclodextrin-epoxychloropropane copolymer with a purity ≥95% and a heavy metal content ≤10 ppm.

[0040] This embodiment 6 also provides a method for preparing a hyperbranched cyclodextrin finishing solution, comprising the following steps: Step (1), Weighing and Gentle Stirring: Add the hyperbranched cyclodextrin aqueous solution to the stirred tank, gently stir with magnetic force at a speed of 280 rpm, and slowly heat to 68 ℃; Step (2), homogenization: Keep the temperature at 68 ℃, increase the stirring speed to 3800 rpm, and homogenize the hyperbranched cyclodextrin aqueous solution for 7 min; Step (3), first stage of addition: keep the temperature at 68 ℃, control the addition time to 8 min, add polyoxyethylene ether, pentaerythritol laurate and polyethylene glycol ester in a thin and uniform flow to ensure that the added materials can be immediately dispersed by the main liquid and avoid local accumulation. Step (4), second stage of addition and high-speed dispersion: keep the temperature at 68 ℃, control the addition time to 22 min, add polyglycerol-3-diisostearate at a slower and uniform speed, and further increase the stirring speed to 6500 rpm. After all additives are added, keep stirring at high speed for 35 min. Step (5), low-speed maturation and filtration: After all raw material components are fully dispersed, heating is stopped and the speed is adjusted to 280 rpm for low-speed maturation. After cooling to room temperature, the mixture is filtered using a 300-mesh filter to remove impurities or gel particles, thus obtaining the hyperbranched cyclodextrin finishing solution.

[0041] This embodiment 6 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, including the following steps: Step (1), Solution preparation: Mix the hyperbranched cyclodextrin finishing solution prepared above with water. By weight, take 7 kg of the hyperbranched cyclodextrin finishing solution and dilute it with 93 kg of water to prepare a padding solution with a mass fraction of 7% of the hyperbranched cyclodextrin finishing solution. Pour the padding solution into the liquid tank. Step (2), Coating: Prepare flame-retardant PET webbing that has been rinsed with clean water. Using a coating / paddling method, coat the surface of the flame-retardant PET webbing with the padding solution. Control the immersion time of the flame-retardant PET webbing in the padding solution to 3.0 min, the padding time to 3.0 min, and control the liquid retention rate (patch-up rate) to 75%. Step (3), pre-baking and heat curing: The coated flame-retardant PET webbing is transferred to an oven for pre-baking and heat curing. The pre-baking temperature is controlled at 115 ℃ for 1.2 min; the heat curing temperature is controlled at 160 ℃ for 3.0 min. During the heat curing film formation process, the hyperbranched cyclodextrin, the fatty acid polyester, and the polyglycerol fatty acid ester self-assemble on the webbing surface through hydrophobic interactions to form a stable core-shell structure finishing layer. Step (4), winding and shaping: After heat curing, the webbing is conveyed to a self-winding device for winding and shaping, thus obtaining the environmentally friendly flame-retardant PET woven sheath. Testing showed that the actual oil content of the finished environmentally friendly flame-retardant PET woven sheath was 1.5%.

[0042] Example 7 Example 7 provides a hyperbranched cyclodextrin finishing solution, comprising the following components: 75.5 kg of hyperbranched cyclodextrin aqueous solution (concentration of 80%); 13.0 kg of fatty acid polyester, specifically polyglycerol laurate (i.e., using polyglycerol-type polyester as the backbone alcohol component and lauric acid as the end-capping acid component); 5.0 kg of polyethylene glycol ester; 1.5 kg of polyoxyethylene ether; and 5.0 kg of polyglycerol fatty acid ester, specifically polyglycerol-3-diisostearate.

[0043] The hyperbranched cyclodextrin is a BETA-cyclodextrin-epoxychloropropane copolymer with a purity ≥95% and a heavy metal content ≤10 ppm.

[0044] This embodiment 7 also provides a method for preparing a hyperbranched cyclodextrin finishing solution, comprising the following steps: Step (1), Weighing and Gentle Stirring: Add the hyperbranched cyclodextrin aqueous solution to the stirred tank, gently stir with magnetic force at a speed of 250 rpm, and slowly heat to 65 ℃; Step (2), homogenization: Keep the temperature at 65 ℃, increase the stirring speed to 3500 rpm, and homogenize the hyperbranched cyclodextrin aqueous solution for 6 min; Step (3), first stage of addition: keep the temperature at 65 ℃, control the addition time to 10 min, add polyoxyethylene ether, polyethylene glycol laurate and polyethylene glycol ester in a thin and uniform flow to ensure that the added materials can be immediately dispersed by the main liquid and avoid local accumulation; Step (4), second stage of addition and high-speed dispersion: keep the temperature at 65 ℃, control the addition time to 20 min, add polyglycerol-3-diisostearate at a slower and uniform speed, and further increase the stirring speed to 6000 rpm. After all additives are added, keep stirring at high speed for 30 min. Step (5), low-speed maturation and filtration: After all raw material components are fully dispersed, heating is stopped and the speed is adjusted to 250 rpm for low-speed maturation. After cooling to room temperature, the mixture is filtered using a 300-mesh filter to remove impurities or gel particles, thus obtaining the hyperbranched cyclodextrin finishing solution.

[0045] This embodiment 7 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, including the following steps: Step (1), Solution preparation: Mix the hyperbranched cyclodextrin finishing solution prepared above with water. By weight, take 5 kg of the hyperbranched cyclodextrin finishing solution and dilute it with 95 kg of water to prepare a padding solution with a mass fraction of 5% of the hyperbranched cyclodextrin finishing solution. Pour the padding solution into the liquid tank. Step (2), Coating: Prepare flame-retardant PET webbing that has been rinsed with clean water. Using a coating / pad-dip method, apply the padding solution to the surface of the flame-retardant PET webbing. Control the immersion time of the flame-retardant PET webbing in the padding solution to 2.0 min, the padding time to 1.0 min, and control the liquid residue ratio (patch-up ratio) to 70%. Step (3), pre-baking and heat curing: The coated flame-retardant PET webbing is transferred to an oven for pre-baking and heat curing in sequence. The pre-baking temperature is controlled at 110 ℃, and the pre-baking time is 1.5 min; the heat curing temperature is controlled at 130 ℃, and the heat curing time is 2.0 min. During the heat curing film formation process, the hyperbranched cyclodextrin, the fatty acid polyester, and the polyglycerol fatty acid ester self-assemble on the webbing surface through hydrophobic interactions to form a stable core-shell structure finishing layer. Step (4), winding and shaping: After heat curing, the webbing is conveyed to a self-winding device for winding and shaping, thus obtaining the environmentally friendly flame-retardant PET woven sheath. Testing showed that the actual oil content of the finished environmentally friendly flame-retardant PET woven sheath was 1.8%.

[0046] Example 8 This embodiment 8 provides a hyperbranched cyclodextrin finishing solution, comprising the following components: 85.0 kg of hyperbranched cyclodextrin aqueous solution (concentration of 80%); 4.0 kg of fatty acid polyester, specifically ethylene glycol stearate; 6.0 kg of polyethylene glycol ester; 2.5 kg of polyoxyethylene ether; and 2.5 kg of polyglycerol fatty acid ester, specifically polyglycerol-6-didecanoate.

[0047] The hyperbranched cyclodextrin is a BETA-cyclodextrin-epoxychloropropane copolymer with a purity ≥95% and a heavy metal content ≤10 ppm.

[0048] This embodiment 8 also provides a method for preparing a hyperbranched cyclodextrin finishing solution, comprising the following steps: Step (1), Weighing and Gentle Stirring: Add the hyperbranched cyclodextrin aqueous solution to the stirred tank, gently stir with magnetic force at a speed of 260 rpm, and slowly heat to 66 ℃; Step (2), homogenization: Keep the temperature at 66 ℃, increase the stirring speed to 3600 rpm, and homogenize the hyperbranched cyclodextrin aqueous solution for 9 min; Step (3), first stage of addition: keep the temperature at 66 ℃, control the addition time to 14 min, add polyoxyethylene ether, ethylene glycol stearate and polyethylene glycol ester in a thin and uniform flow to ensure that the added materials can be immediately dispersed by the main liquid and avoid local accumulation; Step (4), second stage of addition and high-speed dispersion: keep the temperature at 66 ℃, control the addition time to 18 min, add polyglycerol-6-didecanoate at a slower and uniform speed, and further increase the stirring speed to 6200 rpm. After all additives are added, keep stirring at high speed for 32 min. Step (5), low-speed maturation and filtration: After all raw material components are fully dispersed, heating is stopped and the rotation speed is changed to 260 rpm for low-speed maturation. After cooling to room temperature, the mixture is filtered using a 300-mesh filter to remove impurities or gel particles, thus obtaining the hyperbranched cyclodextrin finishing solution.

[0049] This embodiment 8 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, including the following steps: Step (1), Solution preparation: Mix the hyperbranched cyclodextrin finishing solution prepared above with water. Take 8 kg of the hyperbranched cyclodextrin finishing solution and dilute it with 92 kg of water by weight to prepare a padding solution with a mass fraction of 8% of the hyperbranched cyclodextrin finishing solution. Pour the padding solution into the liquid tank. Step (2), Coating: Prepare flame-retardant PET webbing that has been rinsed with clean water. Using a coating / pad-dip method, apply the padding solution to the surface of the flame-retardant PET webbing. Control the immersion time of the flame-retardant PET webbing in the padding solution to 4.0 min, the padding time to 3.5 min, and control the liquid retention rate (patch-up rate) to 68%. Step (3), pre-baking and heat curing: The coated flame-retardant PET webbing is transferred to an oven for pre-baking and heat curing. The pre-baking temperature is controlled at 105 ℃ for 1.5 min; the heat curing temperature is controlled at 150 ℃ for 2.5 min. During the heat curing film formation process, the hyperbranched cyclodextrin, the fatty acid polyester, and the polyglycerol fatty acid ester self-assemble on the webbing surface through hydrophobic interactions to form a stable core-shell structure finishing layer. Step (4), winding and shaping: After heat curing, the webbing is conveyed to a self-winding device for winding and shaping, thus obtaining the environmentally friendly flame-retardant PET woven sheath. Testing showed that the actual oil content of the finished environmentally friendly flame-retardant PET woven sheath was 1.3%.

[0050] Comparative Example Comparative Example 1 Comparative Example 1 provides a method for preparing a flame-retardant PET woven sheath, which has not undergone any VOC-resistant finishing treatment.

[0051] The specific steps are as follows: Prepare flame-retardant PET webbing that has been washed with clean water, without dip coating or pre-baking curing treatment, and directly send it to the self-winding device for winding and shaping to obtain the flame-retardant PET woven sheath.

[0052] Comparative Example 2 Comparative Example 2 provides a finishing solution, which differs from Example 1 only in that the hyperbranched cyclodextrin aqueous solution is replaced with an equal amount of ordinary BETA-cyclodextrin aqueous solution.

[0053] Specifically, it includes the following components: 84.0 kg of ordinary BETA-cyclodextrin aqueous solution (concentration of 80%); 5.0 kg of polyethylene glycol laurate; 5.0 kg of polyethylene glycol ester; 1.0 kg of polyoxyethylene ether; and 5.0 kg of polyglycerol-3-diisostearate.

[0054] Comparative Example 2 also provides a method for preparing a finishing solution, the steps of which are completely consistent with those in Example 1.

[0055] Comparative Example 2 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, with steps completely identical to those in Example 1.

[0056] Comparative Example 3 Comparative Example 3 provides a finishing solution that differs from Example 1 only in that: the fatty acid polyester (polyethylene glycol laurate) is removed, and the weight is made up with an equal amount of water.

[0057] Specifically, it includes the following components: 84.0 kg of hyperbranched cyclodextrin aqueous solution (concentration of 80%, molecular weight of 5000, purity ≥95%, heavy metal content ≤10 ppm); 5.0 kg of water; 5.0 kg of polyethylene glycol ester; 1.0 kg of polyoxyethylene ether; and 5.0 kg of polyglycerol-3-diisostearate.

[0058] Comparative Example 3 also provides a method for preparing a finishing solution, which differs from Example 1 in that: polyethylene glycol laurate is not added in step (3), while the other steps are completely the same.

[0059] Comparative Example 3 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, with steps completely identical to those in Example 1.

[0060] Comparative Example 4 Comparative Example 4 provides a finishing solution that differs from Example 1 only in that: polyglycerol fatty acid ester (polyglycerol-3-diisostearate) is removed, and the weight is made up with an equal amount of water.

[0061] Specifically, it includes the following components: 84.0 kg of hyperbranched cyclodextrin aqueous solution (concentration of 80%, molecular weight of 5000); 5.0 kg of polyethylene glycol laurate; 5.0 kg of polyethylene glycol ester; 1.0 kg of polyoxyethylene ether; and 5.0 kg of water.

[0062] Comparative Example 4 also provides a method for preparing a finishing solution, which differs from Example 1 in that: in step (4), water is added instead of polyglycerol-3-diisostearate, while the other steps are completely the same.

[0063] Comparative Example 4 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, with steps completely identical to those in Example 1.

[0064] Comparative Example 5 Comparative Example 5 provides a finishing solution that differs from Example 1 only in that polyethylene glycol ester and polyoxyethylene ether are removed.

[0065] Specifically, it includes the following components: 84.0 kg of hyperbranched cyclodextrin aqueous solution (concentration of 80%, molecular weight of 5000); 5.0 kg of polyethylene glycol laurate; 6.0 kg of water; and 5.0 kg of polyglycerol-3-diisostearate.

[0066] Comparative Example 5 also provides a method for preparing a finishing solution, which differs from Example 1 in that only polyethylene glycol laurate and water are added in step (3), while the other steps are completely the same.

[0067] Comparative Example 5 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, with steps completely identical to those in Example 1.

[0068] Comparative Example 6 Comparative Example 6 provides a finishing solution with the same composition as Example 1.

[0069] Comparative Example 6 also provides a method for preparing a finishing solution, which differs from Example 1 only in that the stirring speed is lower: Step (1), Weighing and Gentle Stirring: Slowly heat to 65 °C at 250 rpm; Step (2), homogenization: increase the stirring speed to only 1000 rpm (not 3500 rpm) and process for 6 min; Step (3), the first stage adds: conditions are the same as in Example 1; Step (4), second stage of addition and dispersion: increase the stirring speed to only 1500 rpm (not 6000 rpm) and keep stirring for 30 min; Step (5), slow ripening and filtration: same as in Example 1, but a large number of undispersed gel particles are retained at the filter screen.

[0070] Comparative Example 6 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, with steps completely identical to those in Example 1.

[0071] Comparative Example 7 Comparative Example 7 provides a finishing solution with the same composition as Example 1.

[0072] Comparative Example 7 also provides a method for preparing a finishing solution, with the steps being exactly the same as in Example 1.

[0073] Comparative Example 7 also provides a method for preparing an environmentally friendly flame-retardant PET woven sheath, which differs from Example 1 only in that: in step (3), the heat curing temperature is controlled to be only 90 ℃ and the heat curing time is 2.0 min.

[0074] Comparative Example 8 Comparative Example 8 provides a finishing solution, which differs from Example 1 in that it uses a lower amount of hyperbranched cyclodextrin aqueous solution.

[0075] Specifically, it includes the following components: 40.0 kg of hyperbranched cyclodextrin aqueous solution (concentration of 80%, molecular weight of 5000, purity ≥95%, heavy metal content ≤10 ppm); 20.0 kg of fatty acid polyester (polyethylene glycol laurate); 20.0 kg of polyethylene glycol ester; 5.0 kg of polyoxyethylene ether; and 15.0 kg of polyglycerol-3-diisostearate.

[0076] Comparative Example 8 also provides a method for preparing a finishing solution. The operation process and time, temperature and rotation speed parameters of steps (1) to (5) are completely consistent with those of Example 1.

[0077] Application Examples Application Example 1 This application example 1 provides an application of the environmentally friendly flame-retardant PET braided sheath prepared in Example 1 in the protection of the main wiring harness of the center console in the cockpit of a new energy vehicle. The specific implementation process is as follows: Step (1), length cutting: According to the actual assembly length of the main wiring harness inside the center console of the new energy vehicle, the environmentally friendly flame-retardant PET braided sheath prepared in Example 1 is cut to the same length, and the ends are sealed with a hot melt cutting knife to prevent the braided filaments from coming loose.

[0078] Step (2), Expansion and Insertion: Use a wire threader or a special expansion tool to radially expand the flame-retardant PET braided sheath; then pull the main control panel harness (including multiple high and low voltage power lines and signal lines) into the sheath as a whole; after removing the expansion force, the sheath naturally shrinks back and tightly wraps the harness around its perimeter using its high-elasticity braided structure.

[0079] Step (3), end and node fixing: Use automotive-grade low VOC flame retardant tape to wrap and fix the sheath at both ends and at the branch nodes of the wiring harness to ensure that the sheath does not slip off during long-term vehicle vibration.

[0080] Step (4), vehicle application: The wiring harness assembly covered with the protective ring is fixedly installed in the closed wiring channel inside the center console of the car cabin according to the vehicle wiring specifications.

[0081] Under conditions of intense summer sun exposure in vehicles (where temperatures in the enclosed cabin can reach over 80°C), this sheath not only provides excellent abrasion resistance and insulation for the internal wiring harness, but its hyperbranched cyclodextrin core-shell structure finish layer also acts as a "molecular capsule." It quickly captures and firmly locks in short-chain fatty acids, aldehydes, and ketones—odor molecules—emitted from the wiring harness insulation and PET substrate when heated, preventing their volatilization into the air. Testing has shown that the wiring harness area covered by this sheath has no irritating odors, meeting extremely high cabin air quality requirements.

[0082] Application Example 2 This application example 2 provides an application of the environmentally friendly flame-retardant PET braided sheath prepared in Example 2 in the outer layer protection of automotive air conditioning condenser system piping. The specific implementation process is as follows: Step (1), matching and cutting: according to the diameter, direction and design length of the automotive air conditioning refrigerant pipeline and condensate pipeline, cut the environmentally friendly flame-retardant PET braided sheath of the corresponding specification prepared in Example 2.

[0083] Step (2), pipe covering: directly cover the treated braided sheath on the outside of the air conditioning pipe made of aluminum or rubber; in the area where the pipe bends at a large angle, make full use of the flexibility and radial extensibility of the flame-retardant PET braided sheath to make it flat and fit and wrap around the outer wall of the pipe.

[0084] Step (3), fastening and assembly: Use high-temperature resistant plastic cable ties or clamps to securely bind the sheath to the pipeline at the metal connection joints of the pipeline and the key support points of the vehicle body; then assemble the pipeline assembly to the vehicle chassis or the front bulkhead separating the engine compartment and the passenger compartment.

[0085] In the long-term hot-and-cold working environment of automotive piping, this environmentally friendly flame-retardant PET braided sheath effectively prevents friction damage and vibration interference from surrounding mechanical parts. Simultaneously, it boasts excellent flame-retardant properties, with a burning rate of <102mm / min. More importantly, for the air conditioning piping near the cabin air intake, the sheath's efficient odor-locking mechanism significantly reduces TVOCs emitted from heated non-metallic components around the piping, effectively cutting off the path for odors to penetrate into the cabin with the air conditioning airflow.

[0086] Application Example 3 This application example 3 provides an application of the environmentally friendly flame-retardant PET braided sheath prepared in Example 3 in the protection of wiring harnesses for automotive smart seats (cabin interior components). The specific implementation process is as follows: Step (1), Branch Customization: For the branch wiring harness of the heating, ventilation, massage and multi-directional position adjustment motor with complex bottom structure of the car smart seat, cut multiple sections of appropriate length to obtain the environmentally friendly flame-retardant PET braided sheath obtained in Example 3.

[0087] Step (2), cross-wrapping: straighten and gather the scattered bottom wire harnesses of the seat, and completely wrap the main wire harness in a thicker braided sheath; for the branch outlet positions, use a T-shaped or Y-shaped sheath cross-over wrapping method to ensure that the exposed parts of the wire harness are completely covered.

[0088] Step (3), dynamic shaping: In the special wiring channel and slide rail movement gap of the bottom frame of the seat, the wire harness covered with the protective sleeve is dynamically suspended and fixed with a slack by using a special elastic buckle, so as to ensure that when the seat moves back and forth or adjusts its height frequently, the wire harness can move smoothly under the flexible protection of the protective sleeve without being mechanically interfered with or pulled.

[0089] As a core interior component that occupants come into direct and prolonged contact with, the odor emitted from the surrounding area of ​​car seats has a significant impact on their overall experience. During use, when the seat's high-temperature heating function is activated, the local ambient temperature rises significantly. At this time, the hyperbranched cyclodextrins adhering to the surface of the seat cover substrate maintain highly stable adsorption activity, effectively neutralizing and blocking odor molecules emitted from the substrate and the complex wiring harnesses within. This application effectively ensures a healthy breathing environment in the areas of close contact with passengers, keeping the overall odor level and TVOC emissions of the interior at extremely low levels over a long period.

[0090] Performance testing 1. Odor rating test Referring to the enterprise standard GWT A E01-01:2025-08 "Test Methods and Limits for Odor Emissions from Automotive Interiors", the odor levels of the flame-retardant PET woven covers prepared in Examples 1-8 and Comparative Examples 1-8 were evaluated. The specific testing procedure was as follows: using the 1L bottle method, a fixed quantity of cover samples was placed in a sealed bottle and continuously stored in an 80℃ constant temperature chamber for 2 hours to simulate the high-temperature environment inside a car after summer sun exposure, accelerating odor volatilization. After treatment, six professionally trained and rigorously selected odor evaluators conducted blind tests in a specific evaluation room. The evaluators scored the gas inside the bag according to the standard odor intensity levels (Level 1 being odorless, Level 6 being an extremely strong pungent odor) and took the average value.

[0091] 2. VOC and aldehyde volatility test Referring to enterprise standard GWT A E01-04:2025-04, thermal desorption-gas chromatography-mass spectrometry (TDS-GC-MS) was used to quantitatively detect volatile organic compounds (VOCs) in each group of sheath samples. The specific steps were as follows: equal masses of samples were placed in thermal desorption tubes and heated at a specific high temperature for desorption. Subsequently, the volatilized gases were introduced into the chromatographic column by a carrier gas for separation, and qualitative and quantitative analysis was performed by a mass spectrometer detector. The focus was on determining the total capture amount of TVOCs (C6-C16) in the samples, as well as the specific volatilization concentrations of formaldehyde and acetaldehyde.

[0092] 3. Flame retardant performance test Referring to standard FMVSS 49 CFR 571 302-2019, a horizontal burning test was conducted on the prepared flame-retardant PET woven sheath. The specific steps were as follows: the sheath sample was cut to a standard size and fixed on a U-shaped bracket. The free end of the sample was ignited in a specified combustion chamber for 15 seconds, after which the flame source was removed. The distance the flame spread on the sample and the time required were recorded, and the burning rate was calculated. A burning rate <102 mm / min was required to pass the test.

[0093] 4. Water wash resistance durability test To verify the adhesion strength and long-lasting deodorizing ability of the finishing solution on the PET webbing surface, a standard water washing test was conducted on the sheath according to ISO 105-C06 standard. The sample was placed in an aqueous solution containing standard detergent and subjected to five consecutive standard washing cycles at 40°C. After each cycle, it was rinsed with clean water and air-dried. After all water washing was completed, the TVOC capture amount (denoted as "TVOC after washing") was tested again according to the method described in section 2 above, "VOC and aldehyde volatility test". The lower this index, the stronger the resistance of the finishing layer to water washing and peeling, indicating a better self-assembly adhesion effect of the core-shell structure.

[0094] II. Performance Test Results The woven sheaths prepared in Examples 1-8 and Comparative Examples 1-8 were subjected to the above four performance tests, and the performance test results are shown in Table 1 below.

[0095] Table 1. Performance test data of the braided sheaths provided in Examples 1-8 and Comparative Examples 1-8

[0096] III. Summary and Analysis of Test Results As can be seen from the test data in Table 1, the environmentally friendly flame-retardant PET woven sheaths prepared in Examples 1 to 8 of this application all exhibit excellent comprehensive performance, with all indicators significantly superior to the untreated blank substrate. Regarding odor control and VOC degradation, the odor level of each example was consistently controlled between 3.0 and 3.6, the TVOC capture amount remained at a low level of 236.0 μg to 310.0 μg, and the emission of formaldehyde and acetaldehyde decreased. Furthermore, after five rigorous standard water washing cycles, the "TVOC after washing" data of all examples showed almost no significant degradation, remaining within an extremely low range. This fully demonstrates that the various components and proportions of this application can stably construct a robust coating layer on the surface of the webbing. Simultaneously, due to the high-temperature carbonization resistance of the finishing liquid itself, the flame-retardant performance of all examples was not negatively affected, fully meeting the stringent safety standards of the automotive industry.

[0097] Comparative Example 1, as an untreated blank case, highlighted the industry's pain points with its extremely high TVOC and pungent odor. Comparative Example 2, after replacing hyperbranched cyclodextrin with ordinary linear cyclodextrin, still maintained a high initial TVOC capture of 1850.0 μg, and the TVOC capture did not show a significant reduction after washing. This fundamentally proves that the massive cavities created by the hyperbranched structure are a physical prerequisite for achieving high capacity loading. Comparative Examples 3 and 4 removed fatty acid polyester and polyglycerol fatty acid esters, respectively. Although their initial deodorization effect was acceptable, the "TVOC after washing" index rebounded (rising to 1650.0 μg and 1580.0 μg, respectively). This demonstrates that these two bio-based flexible frameworks are indispensable key substances for inducing the system to undergo hydrophobic self-assembly on the PET surface and form a washable "core-shell structure." Comparative Examples 5 and 6 showed uneven coating dispersion and moderate deterioration of all indicators due to the lack of emulsifier or insufficient process speed. Comparative Example 7 also showed a complete collapse of water washability due to the failure of cross-linking curing caused by the excessively low thermosetting temperature. Comparative Example 8, on the contrary, proved that when the concentration of the core active ingredient is below the lower limit, it cannot provide enough "molecular capsules".

[0098] For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations, but obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this invention.

Claims

1. A hyperbranched cyclodextrin finishing solution, characterized in that, The raw materials of the hyperbranched cyclodextrin finishing solution, by weight, include the following components: 67.0 to 96.0 parts of hyperbranched cyclodextrin aqueous solution, 1.0 to 15.0 parts of fatty acid polyester, 1.0 to 10.0 parts of polyethylene glycol ester, 1.0 to 3.0 parts of polyoxyethylene ether, and 1.0 to 10.0 parts of polyglycerol fatty acid ester.

2. The hyperbranched cyclodextrin finishing solution according to claim 1, characterized in that, The mass fraction of the hyperbranched cyclodextrin aqueous solution is 75%~85%; the hyperbranched cyclodextrin is a BETA-cyclodextrin-epoxychloropropane copolymer with a molecular weight of 3000~8000.

3. The hyperbranched cyclodextrin finishing solution according to claim 1, characterized in that, The skeletal alcohol component of the fatty acid polyester is selected from one or more of the following: ethylene glycol type polyester, polyethylene glycol type polyester, propylene glycol type polyester, polypropylene glycol type polyester, glycerol type polyester, polyglycerol type polyester, neopentyl glycol type polyester or pentaerythritol type polyester. The capping acid or ester component of the fatty acid polyester is selected from lauric acid or stearic acid.

4. The hyperbranched cyclodextrin finishing solution according to claim 1, characterized in that, The polyglycerol fatty acid ester is selected from one of polyglycerol-3-diisostearate, polyglycerol-4-didecanoate, or polyglycerol-6-didecanoate.

5. A method for preparing a hyperbranched cyclodextrin finishing solution as described in any one of claims 1 to 4, characterized in that, The specific steps include the following: Step (1): The hyperbranched cyclodextrin aqueous solution is stirred at a speed of 200 rpm to 300 rpm and slowly heated to 60°C to 70°C; Step (2): Maintain the temperature at 60℃~70℃, increase the stirring speed to 3000rpm~4000rpm, and homogenize the hyperbranched cyclodextrin aqueous solution for 5min~10min; Step (3): Keep the temperature at 60℃~70℃, and add the polyoxyethylene ether, fatty acid polyester and polyethylene glycol ester dropwise at a uniform rate, controlling the addition time to 5min~15min, so that the added materials are fully dispersed by the main liquid; Step (4): Keep the temperature at 60℃~70℃, add the polyglycerol fatty acid ester dropwise at a uniform rate, control the addition time to 15min~30min, and increase the stirring speed to 5000 rpm~7000 rpm, and keep stirring at high speed for 20min~40min; Step (5): After all raw material components are fully dispersed, stop heating and reduce the rotation speed to 200 rpm to 300 rpm for maturation. After cooling to room temperature, filter to obtain the hyperbranched cyclodextrin finishing solution.

6. An environmentally friendly flame-retardant PET woven sheath, characterized in that, The invention includes a PET webbing and a finishing layer attached to the surface of the PET webbing, the finishing layer being formed by curing a hyperbranched cyclodextrin finishing liquid as described in any one of claims 1 to 4; wherein the hyperbranched cyclodextrin, the fatty acid polyester, and the polyglycerol fatty acid ester self-assemble to form a core-shell structure through hydrophobic interactions in the finishing layer.

7. The environmentally friendly flame-retardant PET woven sheath according to claim 6, characterized in that, The actual oil content of the environmentally friendly flame-retardant PET woven sheath is 0.1%~2.0%.

8. A method for preparing an environmentally friendly flame-retardant PET woven sheath as described in claim 6 or 7, characterized in that, The specific steps include the following: Step (1): Mix the hyperbranched cyclodextrin finishing solution with water to prepare a padding solution; Step (2): The padding solution is coated onto the surface of the PET webbing using a coating or padding method. The immersion time of the PET webbing in the padding solution is 0.1 min to 5.0 min, the padding time is 0.1 min to 5.0 min, and the liquid retention rate is 60% to 80%. Step (3) involves pre-baking and heat curing the coated PET webbing from step (2) in sequence; wherein the pre-baking temperature is 90℃~120℃ and the pre-baking time is 1min~2min; the heat curing temperature is 120℃~180℃ and the heat curing time is 1min~5min. Step (4) involves winding and shaping the PET webbing after heat curing in step (3) to obtain the environmentally friendly flame-retardant PET woven sheath.

9. The preparation method according to claim 8, characterized in that, In step (1), the padding liquid comprises the following components in 100 parts by weight: 1 to 10 parts of hyperbranched cyclodextrin finishing liquid and 90 to 99 parts of water.

10. The application of an environmentally friendly flame-retardant PET woven sheath as described in any one of claims 6 or 7 in the outer protection of automotive cabin interiors, wiring harnesses, or pipes.

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