Preparation method of fluorine-free anti-absorption polyester industrial yarn

Abstract

This application provides a method for preparing fluorine-free antiwicking polyester industrial yarn, belonging to the field of polyester fiber technology. The method involves using polyurethane polymers or polyurethane prepolymers as the main component, and preparing a hydrophobic oiling agent. Polyester chips are fed into a screw extruder for melt extrusion, then flow out through a spinning assembly. After initial oiling, stretching, and heat setting, a second oiling with the hydrophobic oiling agent is performed. The yarn bundle after the second oiling is dynamically heated by multi-rollers to complete fiber setting and oil film solidification, and then wound to obtain the finished fluorine-free antiwicking polyester industrial yarn with a wicking height ≤7.5cm. This invention abandons the commonly used fluorine-containing waterproofing agents such as C8 and C6 in antiwicking fibers, using non-toxic polyurethane materials as the antiwicking oiling agent, which has environmentally friendly characteristics. Furthermore, the oiling points are flexible, the operation is simple, and it can be easily implemented with existing melt spinning equipment.

Description

Technical Field

[0001] This application relates to a method for preparing fluorine-free, anti-wicking polyester industrial yarn, belonging to the field of polyester fiber technology. Background Technology

[0002] Polyester industrial filament is an industrial filament with a series of excellent properties, including high breaking strength and elastic modulus, moderate resilience, excellent heat setting, and good heat and light resistance. However, products made from ordinary polyester industrial filament currently have poor water resistance. Therefore, anti-wicking treatment during the preparation of polyester industrial filament can reduce the surface tension of the fiber, making the fiber surface difficult to wet, thereby achieving water repellency. There is an urgent need for this in outdoor advertising, conveyor belts, cables, and other fields. Currently, the main components of water-repellent agents used in polyester industrial filament on the market are fluorocarbon chain compounds, such as C8. However, C8 water-repellent agents may produce substances such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) during use, which can accumulate in the human body and harm human health.

[0003] Currently, foreign companies have banned the production and sale of C8 waterproofing and oil-repellent agents, while domestic companies tend to choose C6 and C4 short-chain fluorinated waterproofing agents. However, in the long run, the performance and environmental performance of C6 waterproofing and oil-repellent agents cannot fully meet the relevant requirements. Choosing fluorine-free waterproofing agents is a better way to meet the needs of modern development.

[0004] To date, research on fluorine-free waterproofing agents is limited. Patent CN117510756A discloses a method for preparing an anti-wicking agent, using a fluorine-free acrylate oil as the anti-wicking agent. While it can impart good waterproofing to fabrics, it suffers from drawbacks such as poor durability and reduced hand feel, and has not been applied to the polyester industrial yarn field. Patent CN111877003A discloses an anti-wicking waterproof fiber and its preparation method. However, it uses an anti-wicking agent in the first oiling coat and a common oil in the second oiling coat, which fails to ensure uniform and sufficient adhesion of the spinning oil to the fiber surface, resulting in poor waterproofing. Summary of the Invention

[0005] In view of this, this application provides a method for preparing fluorine-free antiwicking polyester industrial yarn, which abandons the fluorine-containing waterproofing agents such as C8 and C6 commonly used in antiwicking fibers, and selects polyurethane materials that are non-toxic to the human body as the antiwicking main body. It has environmental protection characteristics, is easy to operate, and can be easily achieved using existing melt spinning equipment.

[0006] Specifically, this application is implemented through the following scheme:

[0007] A method for preparing fluorine-free, antiwicking polyester industrial yarn, comprising the following steps:

[0008] Step 1: Formulate a hydrophobic oiling agent based on polyurethane polymers or polyurethane prepolymers.

[0009] Step 2: Polyester chips are fed into a screw extruder for melt extrusion, and then flow out through the spinning assembly. After the first oiling, stretching, and heat setting, a second oiling is performed using the hydrophobic oil agent obtained in Step 1.

[0010] Step 3: After the second oiling, the filament bundle is dynamically heated by multiple rollers to promote and complete fiber shaping and oil film curing, and then wound to obtain the finished fluorine-free anti-wicking polyester industrial yarn with a wicking height ≤7.5 cm; after friction test, the strength retention rate of the polyester industrial yarn is ≥90%.

[0011] The above preparation method selects a completely fluorine-free polyurethane material as the main material of the anti-wicking oil-absorbing agent. By preparing a reactive or non-reactive polyurethane oiling agent, it applies the oil separately to the polyester industrial yarn during spinning. The oiling process occurs during spinning, and the oil film solidifies after stretching and heat setting, thus preparing fluorine-free anti-wicking polyester industrial yarn. This method has the advantages of simple operation and good hydrophobicity, solving the problem of the significant harm to human health and the environment caused by the current use of fluorinated oiling agents. In the above preparation process, dynamic oiling is performed directly during fiber spinning. The polyester industrial yarn prepared in one step has excellent waterproof effect, good abrasion resistance, and good wash resistance.

[0012] Furthermore, as a preferred option:

[0013] In step one, different reactants form reactive or non-reactive oils:

[0014] When the main component is a polyurethane prepolymer, difunctional small molecules are added as chain extenders to form reactive hydrophobic oils. The mass percentage of the chain extender relative to the polyurethane prepolymer is 7-12%.

[0015] The chain extender is a diol or a diamine, etc.

[0016] The molecular weight of the polyurethane prepolymer is 2000~4000 g / mol.

[0017] The second coat of the reactive hydrophobic oiling agent is a chemical oiling method, with an oiling speed of 1~5 m / min, an oiling agent temperature controlled at 50~60 ℃, and an oiling rate of 0.1~0.3 wt%.

[0018] When the main component is polyurethane polymer, a highly soluble and volatile solvent is added as a dispersant to form a non-reactive hydrophobic oil agent. The molecular weight of the polyurethane polymer is 8000~15000 g / mol, and the mass percentage of the dispersant relative to the polyurethane polymer is 5~10%.

[0019] The dispersant is ethyl acetate or N,N-dimethylformamide (DMF), etc.

[0020] The second coat of the non-reactive hydrophobic oiling agent is a physical oiling method, with an oiling speed of 5~10 m / min, an oiling agent temperature of 80~90 ℃, and an oiling rate of 0.3~0.5 wt%.

[0021] The above two oiling processes are carried out after the spinning thread has been heat-set. The oiling methods include, but are not limited to, oiling with an oiling wheel or oiling with an oiling nozzle.

[0022] In step two,

[0023] The polyester chips are high-viscosity chips with an intrinsic viscosity of 1.0~1.1 dL / g, a melt extrusion temperature of 280~300℃, and a spinning assembly temperature of 290~300℃.

[0024] The total draw ratio is 3.5 to 4.5 times, and the heat setting temperature is 120 to 140 ℃.

[0025] The first oiling is done with conventional spinning oil, and the oiling methods include, but are not limited to, oiling with an oiling wheel or oiling nozzle. The oiling speed is 1~5 m / min, the oiling agent temperature is controlled at 20~40 ℃, and the oiling rate is 0.4~0.6 wt%.

[0026] In step three, the multi-roller dynamic heating is specifically configured as follows: the oiled filament bundle is stretched and shaped by five pairs of rollers. The first pair is a preheating roller with a heating temperature of 70~80 ℃ and a heating time of 5~15 s; the second pair of hot rollers is a pre-stretching roller with a stretching ratio of 1.1~1.3 times and a heating temperature of 90~100 ℃; the third pair is a main stretching roller with a stretching ratio of 3.5~4.0 times and a heating temperature of 130~150 ℃ and a heating time of 3~10 s; the fourth pair of rollers is a secondary stretching roller with a stretching ratio of 1.4~1.5 times and a heating temperature of 160~200 ℃; and the fifth pair of rollers is a heat-setting roller with a heating temperature of 180~220 ℃ and a heating time of 3~8 s.

[0027] The fiber bundle is cured into a film or reacts with the rollers through contact heating. Physical oiling achieves film formation by volatilizing the oil agent at high temperatures during the multi-roller dynamic heating process, while chemical oiling promotes chain extension and achieves reactive film formation through high temperatures during the multi-roller dynamic heating process. The combination of oiling and multi-roller dynamic heating, utilizing the fiber spinning oiling method, achieves a process in which the oil agent is uniformly adhered to the fiber surface.

[0028] The winding speed is 3800~4500 m / min, and the filament bundle is wound at high speed.

[0029] Compared with existing antiwicking fiber preparation technologies, the beneficial effects of this application are summarized as follows:

[0030] (1) Compared with the waterproofing agents containing perfluorooctyl sulfonyl derivatives (PFOS) and perfluorooctanoic acid (PFOA) commonly used in the polyester field, the present invention uses fluorine-free polyurethane oil agents, which are non-toxic and harmless to human health and the environment, and have outstanding environmental protection advantages.

[0031] (2) Compared with other non-fluorine anti-core oil absorbents, the present invention uses polyurethane anti-core oil absorbents, which can not only give polyester industrial yarn good hydrophobicity, but also polyurethane has excellent abrasion resistance. After friction test, the strength retention rate of polyester industrial yarn is greater than 90%, which makes the polyester industrial yarn prepared by the present invention have excellent abrasion resistance.

[0032] (3) The method proposed in this invention can be completed using existing melt spinning devices and equipment, without the need to add or purchase new processing equipment, and the cost of technical improvement is low.

[0033] (4) Although the fluorine-free antiwicking agents reported in existing research have low toxicity, most of them do not achieve the ideal antiwicking effect. The fluorine-free antiwicking fiber prepared by this invention has a wicking height of less than 7.5 cm, which is both environmentally friendly and has a good antiwicking effect, comparable to fluorine-containing antiwicking agents. Detailed Implementation

[0034] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the technical solutions of this application will be further described in detail below with reference to specific examples in the embodiments of this application. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit the technical solutions of this application. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] Example 1

[0036] This embodiment describes a method for preparing fluorine-free, anti-wicking polyester industrial yarn, with the following steps:

[0037] Step 1, Preparation of hydrophobic oiling agent: Using polyurethane polymer (molecular weight of 8000 g / mol) as the main material and ethyl acetate (highly soluble and highly volatile) as the solvent, prepare a hydrophobic oiling agent for polyester industrial yarn. In this preparation process, the mass percentage of ethyl acetate relative to the polyurethane polymer is 5%.

[0038] Step 2, oiling the spinning line: High-viscosity PET chips are used as raw materials, which are fed into the screw extruder for melt extrusion. After flowing out through the spinning assembly, they are first oiled, stretched, and heat-set, and then oiled a second time using the above-mentioned hydrophobic oiling agent.

[0039] The intrinsic viscosity of the high-viscosity PET chips is 1.0 dL / g, the melt extrusion temperature is 280 ℃, and the spinning assembly temperature is 290 ℃.

[0040] Both the first and second oiling processes were carried out using oil tankers. The oiling speed for the first oiling was 1 m / min, and the oil temperature was controlled at 20 ℃. The oiling speed for the second oiling was 10 m / min, and the oil temperature was controlled at 90 ℃. The total oiling rate for the first and second oiling processes was 0.7 wt%.

[0041] The draw ratio is 3.5, and the heat setting temperature is 120 ℃.

[0042] Step 3, Oil Film Curing of the Spun Yarn: After two rounds of oiling, the yarn bundle is dynamically heated by multiple rollers to promote fiber setting and oil film curing. The yarn bundle is wound using a high-speed winding method to obtain anti-wicking polyester industrial yarn. The specific settings for the multi-roller dynamic heating are as follows: the oiled yarn bundle is stretched and shaped by five pairs of rollers. The first pair is a preheating roller, heated to 70℃ for 5 seconds; the second pair is a pre-stretching roller, with a stretch ratio of 1.1 times and a heating temperature of 90℃; the third pair is a main stretching roller, with a stretch ratio of 3.5 times and a heating temperature of 130℃ for 3 seconds; the fourth pair is a secondary stretching roller, with a stretch ratio of 1.4 times and a heating temperature of 160℃; and the fifth pair is a heat-setting roller, heated to 180℃ for 3 seconds. During the contact heating process between the yarn bundle and each roller, the oil evaporates at high temperature and solidifies into a film. The winding speed is 3800 m / min.

[0043] Tests showed that the wicking height of the fluorine-free antiwicking polyester industrial yarn prepared in this embodiment was 6.3 cm; after friction tests, the strength retention rate of the polyester industrial yarn was 90%.

[0044] Example 2

[0045] This embodiment describes a method for preparing fluorine-free, anti-wicking polyester industrial yarn, with the following steps:

[0046] Step 1, Preparation of hydrophobic oiling agent: Using polyurethane polymer (molecular weight 11000 g / mol) as the main material and DMF, which has high solubility and strong volatility, as the solvent, prepare a hydrophobic oiling agent for polyester industrial yarn. In this preparation process, the mass percentage of DMF added relative to polyurethane polymer is 7%.

[0047] Step 2, oiling the spinning line: High-viscosity PET chips are used as raw materials, which are fed into the screw extruder for melt extrusion. After flowing out through the spinning assembly, they are first oiled, stretched, and heat-set, and then oiled a second time using the above-mentioned hydrophobic oiling agent.

[0048] The intrinsic viscosity of the high-viscosity PET chips is 1.02 dL / g, the melt extrusion temperature is 290 ℃, and the spinning assembly temperature is 300 ℃.

[0049] Both the first and second oiling processes were carried out using oil tankers. The oiling speed for the first oiling was 2 m / min, and the oil temperature was controlled at 25 ℃. The oiling speed for the second oiling was 7 m / min, and the oil temperature was controlled at 85 ℃. The total oiling rate for the first and second oiling processes was 0.9 wt%.

[0050] The draw ratio is 3.5, and the heat setting temperature is 130 ℃.

[0051] Step 3, Oil Film Curing of the Spun Yarn: After the second oiling, the yarn bundle is dynamically heated by multiple rollers to promote fiber setting and oil film curing. The yarn bundle is wound using a high-speed winding method to obtain anti-wicking polyester industrial yarn. The specific settings for the multi-roller dynamic heating are as follows: the oiled yarn bundle is stretched and shaped by five pairs of rollers. The first pair is a preheating roller, with a heating temperature of 72℃ and a heating time of 7 seconds; the second pair of hot rollers is for pre-stretching, with a stretch ratio of 1.2 times and a temperature of 93℃; the third pair is for main stretching, with a stretch ratio of 3.6 times and a temperature of 135℃ and a heating time of 4 seconds; the fourth pair of rollers is for secondary stretching, with a stretch ratio of 1.45 times and a heating temperature of 170℃; and the fifth pair of rollers is for heat setting, with a heating temperature of 190℃ and a heating time of 4 seconds. During the contact heating process between the yarn bundle and each roller, the oil evaporates at high temperature and solidifies into a film. The winding speed is 3900 m / min.

[0052] According to the test, the wicking height of the fluorine-free antiwicking polyester industrial yarn prepared in this embodiment is 6.1 cm, and the strength retention rate of the polyester industrial yarn is 92% after the friction test.

[0053] Example 3

[0054] This embodiment describes a method for preparing fluorine-free, anti-wicking polyester industrial yarn, with the following steps:

[0055] Step 1, Preparation of hydrophobic oiling agent: Using polyurethane polymer (molecular weight of 15000 g / mol) as the main material and ethyl acetate (highly soluble and highly volatile) as the solvent, prepare a hydrophobic oiling agent for polyester industrial yarn. In this preparation process, the mass percentage of ethyl acetate relative to the polyurethane polymer is 10%.

[0056] Step 2, oiling the spinning line: High-viscosity PET chips are used as raw materials, which are fed into the screw extruder for melt extrusion. After flowing out through the spinning assembly, they are first oiled, stretched, and heat-set, and then oiled a second time using the above-mentioned hydrophobic oiling agent.

[0057] The intrinsic viscosity of the high-viscosity PET chips is 1.03 dL / g, the melt extrusion temperature is 280 ℃, and the spinning assembly temperature is 290 ℃.

[0058] Both the first and second oiling processes were carried out using oil tankers. The oiling speed for the first oiling was 3 m / min, and the oil temperature was controlled at 30 ℃. The oiling speed for the second oiling was 5 m / min, and the oil temperature was controlled at 80 ℃. The total oiling rate for the first and second oiling processes was 1.1 wt%.

[0059] The draw ratio is 4.0, and the heat setting temperature is 130 ℃.

[0060] Step 3, Oil Film Curing of the Spun Yarn: After two rounds of oiling, the yarn bundle is dynamically heated by multiple rollers to promote fiber setting and oil film curing. The yarn bundle is wound using a high-speed winding method to obtain anti-wicking polyester industrial yarn. The specific settings for the multi-roller dynamic heating are as follows: the oiled yarn bundle is stretched and shaped by five pairs of rollers. The first pair is a preheating roller, with a heating temperature of 75℃ and a heating time of 9 s; the second pair of hot rollers is for pre-stretching, with a stretch ratio of 1.2 times and a temperature of 96℃; the third pair is for main stretching, with a stretch ratio of 3.7 times and a temperature of 140℃ and a heating time of 5 s; the fourth pair of rollers is for secondary stretching, with a stretch ratio of 1.46 times and a heating temperature of 180℃; and the fifth pair of rollers is for heat setting, with a heating temperature of 200℃ and a heating time of 5 s. During the contact heating process between the yarn bundle and each roller, the high temperature promotes chain extension and reactive film formation. The winding speed is 4000 m / min.

[0061] According to the test, the wicking height of the fluorine-free antiwicking polyester industrial yarn prepared in this embodiment is 5.2 cm, and the strength retention rate of the polyester industrial yarn is 93% after the friction test.

[0062] Example 4

[0063] This embodiment describes a method for preparing fluorine-free, anti-wicking polyester industrial yarn, with the following steps:

[0064] Step 1, Preparation of hydrophobic oiling agent: Using polyurethane prepolymer (molecular weight of 2000 g / mol) as the main material and ethylene glycol as the chain extender, prepare a hydrophobic oiling agent for polyester industrial yarn. In this preparation process, the mass percentage of ethylene glycol added relative to the polyurethane prepolymer is 7%.

[0065] Step 2, oiling the spinning line: High-viscosity PET chips are used as raw materials, which are fed into the screw extruder for melt extrusion. After flowing out through the spinning assembly, they are first oiled, stretched, and heat-set, and then oiled a second time using the above-mentioned hydrophobic oiling agent.

[0066] The intrinsic viscosity of the high-viscosity PET chips is 1.05 dL / g, the melt extrusion temperature is 300 ℃, and the spinning assembly temperature is 300 ℃.

[0067] Both the first and second oiling processes use nozzles for oiling. The oiling speed for the first oiling is 4 m / min, and the oil temperature is controlled at 30 ℃. The oiling speed for the second oiling is 1 m / min, and the oil temperature is controlled at 50 ℃. The total oiling rate for the first and second oiling processes is 0.5 wt%.

[0068] The draw ratio is 4.5, and the heat setting temperature is 140 ℃.

[0069] Step 3, Oil Film Curing of the Spun Yarn: After two rounds of oiling, the yarn bundle is dynamically heated by multiple rollers to promote fiber setting and oil film curing. The yarn bundle is wound using a high-speed winding method to obtain anti-wicking polyester industrial yarn. The specific settings for the multi-roller dynamic heating are as follows: the oiled yarn bundle is stretched and shaped by five pairs of rollers. The first pair is a preheating roller, with a heating temperature of 77℃ and a heating time of 11 s; the second pair of hot rollers is for pre-stretching, with a stretch ratio of 1.3 times and a temperature of 95℃; the third pair is for main stretching, with a stretch ratio of 3.8 times and a temperature of 135℃ and a heating time of 7 s; the fourth pair of rollers is for secondary stretching, with a stretch ratio of 1.48 times and a heating temperature of 190℃; and the fifth pair of rollers is for heat setting, with a heating temperature of 200℃ and a heating time of 6 s. During the contact heating process between the yarn bundle and each roller, the high temperature promotes chain extension and reactive film formation. The winding speed is 4200 m / min.

[0070] Tests showed that the wicking height of the fluorine-free antiwicking polyester industrial yarn prepared in this embodiment was 3.1 cm, and the strength retention rate of the polyester industrial yarn was 95% after friction test.

[0071] Example 5

[0072] This embodiment describes a method for preparing fluorine-free, anti-wicking polyester industrial yarn, with the following steps:

[0073] Step 1, Preparation of hydrophobic oiling agent: Using polyurethane prepolymer (molecular weight of 3000 g / mol) as the main material and ethylenediamine as the chain extender, prepare a hydrophobic oiling agent for polyester industrial yarn. In this preparation process, the mass percentage of ethylenediamine added relative to the polyurethane prepolymer is 10%.

[0074] Step 2, oiling the spinning line: High-viscosity PET chips are used as raw materials, which are fed into the screw extruder for melt extrusion. After flowing out through the spinning assembly, they are first oiled, stretched, and heat-set, and then oiled a second time using the above-mentioned hydrophobic oiling agent.

[0075] The intrinsic viscosity of the high-viscosity PET chips is 1.08 dL / g, the melt extrusion temperature is 280 ℃, and the spinning assembly temperature is 295 ℃.

[0076] The first oiling is done by oil tanker, and the second oiling is done by oil nozzle. The oiling speed for the first oiling is 4 m / min and the oil temperature is controlled at 35 ℃. The oiling speed for the second oiling is 3 m / min and the oil temperature is controlled at 55 ℃. The total oiling rate of the first and second oiling is 0.7 wt%.

[0077] The draw ratio is 3.5, and the heat setting temperature is 120 ℃.

[0078] Step 3, Oil Film Curing of the Spun Yarn: After two rounds of oiling, the yarn bundle is dynamically heated by multiple rollers to promote fiber setting and oil film curing. The yarn bundle is wound using a high-speed winding method to obtain anti-wicking polyester industrial yarn. The specific settings for the multi-roller dynamic heating are as follows: the oiled yarn bundle is stretched and shaped by five pairs of rollers. The first pair is a preheating roller, with a heating temperature of 75℃ and a heating time of 13 s; the second pair of hot rollers is for pre-stretching, with a stretch ratio of 1.2 times and a temperature of 98℃; the third pair is for main stretching, with a stretch ratio of 3.9 times and a temperature of 145℃ and a heating time of 9 s; the fourth pair of rollers is for secondary stretching, with a stretch ratio of 1.48 times and a heating temperature of 195℃; and the fifth pair of rollers is for heat setting, with a heating temperature of 210℃ and a heating time of 7 s. During the contact heating process between the yarn bundle and each roller, the high temperature promotes chain extension and reactive film formation. The winding speed is 4400 m / min.

[0079] Tests showed that the wicking height of the fluorine-free antiwicking polyester industrial yarn prepared in this embodiment was 4.5 cm, and the strength retention rate of the polyester industrial yarn was 96% after a friction test.

[0080] Example 6

[0081] This embodiment describes a method for preparing fluorine-free, anti-wicking polyester industrial yarn, with the following steps:

[0082] Step 1, Preparation of hydrophobic oiling agent: Using polyurethane prepolymer (molecular weight of 4000 g / mol) as the main material and ethylene glycol as the chain extender, prepare a hydrophobic oiling agent for polyester industrial yarn. In this preparation process, the mass percentage of ethylene glycol added relative to the polyurethane prepolymer is 12%.

[0083] Step 2, oiling the spinning line: High-viscosity PET chips are used as raw materials, which are fed into the screw extruder for melt extrusion. After flowing out through the spinning assembly, they are first oiled, stretched, and heat-set, and then oiled a second time using the above-mentioned hydrophobic oiling agent.

[0084] The intrinsic viscosity of the high-viscosity PET chips is 1.0 dL / g, the melt extrusion temperature is 280 ℃, and the spinning assembly temperature is 290 ℃.

[0085] Both the first and second oiling processes were carried out using oil tankers. The oiling speed for the first oiling was 5 m / min, and the oil temperature was controlled at 40 ℃. The oiling speed for the second oiling was 5 m / min, and the oil temperature was controlled at 60 ℃. The total oiling rate for the first and second oiling processes was 0.9 wt%.

[0086] The draw ratio is 4.5, and the heat setting temperature is 130 ℃.

[0087] Step 3, Oil Film Curing of the Spun Yarn: After two rounds of oiling, the yarn bundle is dynamically heated by multiple rollers to promote fiber setting and oil film curing. The yarn bundle is wound using a high-speed winding method to obtain anti-wicking polyester industrial yarn. The specific settings for the multi-roller dynamic heating are as follows: the oiled yarn bundle is stretched and shaped by five pairs of rollers. The first pair is a preheating roller, heated to 80℃ for 15 seconds; the second pair is a pre-stretching roller, stretched 1.3 times at 100℃; the third pair is a main stretching roller, stretched 4.0 times at 150℃ for 10 seconds; the fourth pair is a secondary stretching roller, stretched 1.5 times at 200℃; and the fifth pair is a heat-setting roller, heated 220℃ for 8 seconds. During the contact heating process between the yarn bundle and each roller, the high temperature promotes chain extension and reactive film formation. The winding speed is 4500 m / min.

[0088] Tests showed that the wicking height of the fluorine-free antiwicking polyester industrial yarn prepared in this embodiment was 3.2 cm, and the strength retention rate of the polyester industrial yarn was 95% after friction test.

[0089] The above-described embodiments are merely illustrative of several feasible implementations of the present invention, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of the present invention, nor are the embodiments intended to limit the scope of protection in the claims of the present invention. For those skilled in the art, various modifications and improvements can be made without departing from the concept of the present invention. All equivalent implementations or changes that do not depart from the present invention should be included in the technology of the present invention.

Claims

1. A method for preparing fluorine-free, anti-wicking polyester industrial yarn, characterized in that, The steps are as follows: Step 1: Formulate a hydrophobic oiling agent based on polyurethane polymers or polyurethane prepolymers. Step 2: Polyester chips are fed into a screw extruder for melt extrusion, and then flow out through the spinning assembly. After the first oiling, stretching, and heat setting, a second oiling is performed using the hydrophobic oil agent obtained in Step 1. Step 3: After the second oiling, the filament bundle is dynamically heated by multiple rollers to complete fiber shaping and oil film curing, and then wound to obtain the finished fluorine-free anti-wicking polyester industrial yarn with a wicking height ≤ 7.5 cm; The hydrophobic oiling agent is a reactive oiling agent, mainly composed of a polyurethane prepolymer with a molecular weight of 2000~4000 g / mol, with the addition of difunctional small molecules as chain extenders to form the hydrophobic oiling agent. The mass percentage of the chain extender relative to the polyurethane prepolymer is 7~12%. Alternatively, the hydrophobic oil agent may be a non-reactive oil agent, primarily composed of polyurethane polymer with a molecular weight of 8000~15000 g / mol, with the addition of a dispersant to form the hydrophobic oil agent, wherein the mass percentage of the dispersant relative to the polyurethane polymer is 5~10%; In step two, the first oiling is done with conventional spinning oil, using an oiling roller or oil nozzle. The oiling speed is 1~5 m / min, the oil temperature is controlled at 20~40 ℃, and the oiling rate is 0.4~0.6 wt%. After the first oiling, the total draw ratio reaches 3.5~4.5 times, and the heat setting temperature is 120~140 ℃. In step three, the multi-roller dynamic heating is carried out through five pairs of rollers. The first pair of rollers is a preheating roller with a heating temperature of 70~80℃ and a heating time of 5~15 s. The second pair of rollers is a pre-stretching roller with a stretching ratio of 1.1~1.3 times and a heating temperature of 90~100 ℃. The third pair of rollers is a main stretching roller with a stretching ratio of 3.5~4.0 times and a heating temperature of 130~150 ℃ and a heating time of 3~10 s. The fourth pair of rollers is a secondary stretching roller with a stretching ratio of 1.4~1.5 times and a heating temperature of 160~200 ℃. The fifth pair of rollers is a heat setting roller with a heating temperature of 180~220 ℃ and a heating time of 3~8 s. The filament bundle is heated in contact with each roller to complete the curing or reaction film formation.

2. The method for preparing a fluorine-free, anti-wicking polyester industrial yarn according to claim 1, characterized in that: The chain extender is a diol or a diamine.

3. The method for preparing a fluorine-free, anti-wicking polyester industrial yarn according to claim 1, characterized in that: The second oiling process uses a chemical method, with an oiling speed of 1~5 m / min, an oil agent temperature controlled at 50~60 ℃, and an oiling rate of 0.1~0.3 wt%.

4. The method for preparing a fluorine-free, anti-wicking polyester industrial yarn according to claim 1, characterized in that: The dispersant is ethyl acetate or N,N-dimethylformamide.

5. The method for preparing a fluorine-free, anti-wicking polyester industrial yarn according to claim 1, characterized in that: The second oiling process uses a physical method, with an oiling speed of 5-10 m / min, an oil temperature controlled at 80-90 ℃, and an oiling rate of 0.3-0.5 wt%.

6. The method for preparing a fluorine-free, anti-wicking polyester industrial yarn according to claim 1, characterized in that: The polyester chips are high-viscosity chips with an intrinsic viscosity of 1.0~1.1 dL / g, a melt extrusion temperature of 280~300 ℃, and a spinning assembly temperature of 290~300 ℃.