A high-shrinkage nylon production process

Abstract

This application relates to a high-shrinkage nylon production process, and pertains to the field of nylon fiber technology. The high-shrinkage nylon production process includes the following steps: S1, drying nylon granules, then mixing the dried nylon granules with an antistatic agent and performing melt extrusion to obtain a spinning melt; S2, spinning the spinning melt to obtain a composite fiber, and then performing stretching treatment to obtain nylon fiber. This application has the effect of improving the shrinkage of nylon fiber.

Description

Technical Field

[0001] This application relates to the field of nylon fiber technology, and in particular to a high-shrinkage nylon production process. Background Technology

[0002] Compared with polyester and acrylic, nylon has many advantages, such as being strong and wear-resistant, having low density, and producing lightweight fabrics. As a new type of textile raw material, high-shrinkage nylon fiber endows nylon with high shrinkage and moderate strength, greatly expanding its application fields. For example, it can be blended with conventional products to form yarn, and then boiled or steamed in a tension-free state. The high-shrinkage fiber curls up, while the conventional fiber curls into loops due to the constraint of the high-shrinkage fiber, resulting in a fluffy and round yarn like wool, which improves the product grade and increases the variety of patterns. Therefore, the application scenarios of high-shrinkage nylon fiber are very broad.

[0003] Existing technology discloses a method for producing high-shrinkage nylon fiber using copolymerized nylon 6 and nylon 66 chips as raw materials, with nylon 6 accounting for 50-80 wt% and nylon 66 accounting for 20-50 wt%. The fibers are melted, mixed, and extruded in a screw extruder under nitrogen protection, then spun on a spinning machine. After component filtration, oiling, pre-networking, stretching, heat setting, networking, and high-speed winding, high-shrinkage nylon fiber is obtained. However, the use of nylon 6 and nylon 66 as raw materials means that the nylon raw materials are prone to electrostatic accumulation and mutual repulsion, thus reducing the shrinkage of the nylon. Summary of the Invention

[0004] To improve the shrinkage of nylon fibers, this application provides a high-shrinkage nylon production process.

[0005] This application provides a high-shrinkage nylon production process, which adopts the following technical solution:

[0006] A high-shrinkage nylon production process includes the following steps:

[0007] S1. The nylon granules are dried, and then the dried nylon granules are mixed with an antistatic agent and melt-extruded to obtain a spinning melt.

[0008] S2. The spinning melt is spun into composite fibers, and then stretched to obtain nylon fibers.

[0009] The antistatic agent includes graphene oxide.

[0010] The nylon fiber prepared by blending an antistatic agent made from graphene oxide with nylon particles using the above-mentioned technical solution exhibits excellent high shrinkage properties. The specific reasons are as follows:

[0011] Graphene oxide has good electrical conductivity, which can effectively improve the electrical conductivity of nylon fibers, reduce electrostatic deposition, and thus improve the shrinkage rate of nylon fibers.

[0012] Preferably, the mass ratio of the nylon particles to the antistatic agent is 1:(0.04-0.06).

[0013] By adopting the above technical solution and controlling the mass ratio of nylon particles and antistatic agent within the above range, the electrical conductivity of nylon fibers can be effectively improved.

[0014] Preferably, the antistatic agent also includes carbon nanotubes.

[0015] By adopting the above technical solution, carbon nanotubes have good electrical conductivity, which can further reduce electrostatic deposition and further improve the shrinkage rate of nylon fibers.

[0016] Secondly, the curved shape and large aspect ratio of carbon nanotubes can act as a connector between graphene oxide sheets, thereby reducing the aggregation of graphene oxide and effectively improving the dispersibility of graphene oxide.

[0017] In addition, the combined use of graphene oxide and carbon nanotubes has a good synergistic effect when combined with nylon particles. It can increase the compatibility between graphene oxide, carbon nanotubes and nylon particles, thereby improving the conductivity of nylon fibers. This further reduces electrostatic deposition and increases the shrinkage rate of nylon fibers.

[0018] Preferably, the mass ratio of graphene oxide to carbon nanotubes is (5-7):1.

[0019] By adopting the above technical solution, the mass ratio of graphene oxide and carbon nanotubes is controlled within the above range, which has a positive effect on improving the shrinkage rate of nylon fiber.

[0020] Preferably, the graphene oxide is prepared by modification, and the method for preparing the modified graphene oxide includes the following steps:

[0021] Graphene oxide was added to deionized water and stirred until homogeneous to obtain a graphene oxide dispersion. Dodecylamine was added to anhydrous ethanol and stirred until homogeneous to obtain a dodecylamine solution. The graphene oxide dispersion and the dodecylamine solution were then mixed and stirred until homogeneous. After centrifugation and washing, and freeze-drying, modified graphene oxide was obtained.

[0022] By adopting the above technical solution, dodecylamine is used to modify graphene oxide, which effectively improves the interfacial compatibility between graphene oxide and nylon particles, increases the interlayer spacing of graphene oxide, and improves the stability of graphene oxide in nylon matrix.

[0023] Preferably, the mass ratio of graphene oxide to dodecylamine is 1:(12-16).

[0024] By adopting the above technical solution, the mass ratio of graphene oxide to dodecylamine is controlled within the above range, which has a positive effect on improving the stability of graphene oxide in nylon matrix.

[0025] Preferably, glycidol is added during the graphene oxide modification process, i.e., the graphene oxide modification preparation method includes the following steps:

[0026] S100. Add graphene oxide to deionized water and stir evenly to obtain graphene oxide dispersion. Add dodecylamine to anhydrous ethanol and stir evenly to obtain dodecylamine solution. Mix the graphene oxide dispersion and dodecylamine solution and stir evenly. Then centrifuge and wash, freeze dry, and obtain primary modified graphene oxide.

[0027] S200. Primary modified graphene oxide and glycidol are mixed and stirred evenly. Nitrogen gas is then introduced under heating conditions and stirred to obtain a black mud-like substance. The black mud-like substance is then washed with methanol, allowed to precipitate naturally, and the supernatant is removed. The precipitate is then dialyzed in ultrapure water and subjected to heating treatment. An ice-water solution of sodium borohydride is added and stirred evenly. The reaction solution is then dialyzed in ultrapure water and freeze-dried to obtain modified graphene oxide.

[0028] By adopting the above technical solution, hyperbranched polyglycerol formed by glycidol is covalently grafted onto the surface of graphene oxide. The molecular structure of hyperbranched polyglycerol contains a number of hydroxyl groups, which helps to improve the hydrophilicity of graphene oxide, thereby improving the moisture absorption of nylon fiber and improving the high shrinkage of nylon fiber.

[0029] Preferably, polyvinylpyrrolidone is also added in step S1, and the specific steps of step S1 are as follows:

[0030] The nylon granules are dried, and then the dried nylon granules, antistatic agent, and polyvinylpyrrolidone are mixed and melt-extruded to obtain a spinning melt.

[0031] The polyvinylpyrrolidone accounts for (2-4)% of the mass of the antistatic agent.

[0032] By adopting the above technical solution, the ketone group in polyvinylpyrrolidone can form hydrogen bonds and other forces with the amide group in nylon particles, thereby creating an affinity between polyvinylpyrrolidone and nylon particles. In addition, polyvinylpyrrolidone has good wettability to nylon particles, thereby improving the hydrophilicity of nylon fibers and improving the shrinkage of nylon fibers.

[0033] In addition, electrostatic forces can be formed between polyvinylpyrrolidone and carbon nanotubes, which enables polyvinylpyrrolidone to coat carbon nanotubes, improve the dispersibility of carbon nanotubes in nylon particles, and further enhance the conductivity of carbon nanotubes.

[0034] Furthermore, it makes the surface of carbon nanotubes more hydrophilic, improves the compatibility between carbon nanotubes and nylon particles, and enhances the interfacial bonding force between carbon nanotubes and nylon particles, thereby improving the mechanical properties of nylon fibers.

[0035] In addition, polyvinylpyrrolidone can form an interfacial layer between carbon nanotubes and nylon particles, which has good toughness and strength. This allows it to disperse stress at the interface, prevent crack propagation, and further improve the mechanical properties of nylon fibers.

[0036] Preferably, a metal salt is also added in step S1, and the specific steps of step S1 are as follows:

[0037] The nylon granules are dried, and then the dried nylon granules, antistatic agent, polyvinylpyrrolidone, and metal salt are mixed and melt-extruded to obtain a spinning melt.

[0038] The metal salt accounts for (0.5-2)% of the mass of the nylon particles.

[0039] By adopting the above technical solution, metal ions can penetrate into the nylon molecular chain, disrupt the regularity of the molecular chain, reduce the crystallinity, and thus improve the shrinkage of nylon fiber.

[0040] Preferably, the metal salt is zinc chloride.

[0041] By adopting the above technical solution, zinc chloride and polyvinylpyrrolidone can form a complex, which can enhance the stability of nylon fibers and thus improve the mechanical properties of nylon fibers.

[0042] In summary, this application includes at least one of the following beneficial technical effects:

[0043] 1. Graphene oxide has good electrical conductivity, which can effectively improve the electrical conductivity of nylon fibers, reduce electrostatic deposition, and thus improve the shrinkage rate of nylon fibers.

[0044] 2. Carbon nanotubes have good electrical conductivity, which can further reduce electrostatic deposition. The combined use of graphene oxide and carbon nanotubes has a good synergistic effect with nylon particles, which can increase the compatibility between graphene oxide, carbon nanotubes and nylon particles, thereby improving the electrical conductivity of nylon fibers. This further reduces electrostatic deposition and improves the shrinkage rate of nylon fibers. Detailed Implementation

[0045] The present application will be further described in detail below with reference to the embodiments and comparative examples. The raw materials involved in the present application can all be obtained commercially, and the polyvinylpyrrolidone is provided by Hefei Tianjian Chemical Co., Ltd.

[0046] Example 1

[0047] A high-shrinkage nylon production process includes the following steps:

[0048] S1. Dry 100g of nylon granules, then mix the dried nylon granules with 4g of antistatic agent and melt-extrude them at 250℃ to obtain a spinning melt.

[0049] S2. The spinning melt is spun into composite fibers through a micro spinning machine. Then, the fibers are stretched four times under the action of the stretching rollers through a hot stretching device with the heating cylinder temperature set at 120°C to obtain nylon fibers.

[0050] The antistatic agent includes graphene oxide.

[0051] Example 2

[0052] A high-shrinkage nylon production process includes the following steps:

[0053] S1. Dry 100g of nylon granules, then mix the dried nylon granules with 6g of antistatic agent and melt and extrude them at 250℃ to obtain a spinning melt.

[0054] S2. The spinning melt is spun into composite fibers through a micro spinning machine. Then, the fibers are stretched four times under the action of the stretching rollers through a hot stretching device with the heating cylinder temperature set at 120°C to obtain nylon fibers.

[0055] The antistatic agent includes graphene oxide.

[0056] Example 3

[0057] A high-shrinkage nylon production process includes the following steps:

[0058] S1. Dry 100g of nylon granules, then mix the dried nylon granules with 5g of antistatic agent and melt and extrude them at 250℃ to obtain a spinning melt.

[0059] S2. The spinning melt is spun into composite fibers through a micro spinning machine. Then, the fibers are stretched four times under the action of the stretching rollers through a hot stretching device with the heating cylinder temperature set at 120°C to obtain nylon fibers.

[0060] The antistatic agent includes graphene oxide.

[0061] Example 4

[0062] The difference between Example 4 and Example 3 is that the antistatic agent also includes carbon nanotubes, and the mass ratio of graphene oxide to carbon nanotubes is 5:1.

[0063] Example 5

[0064] The difference between Example 5 and Example 3 is that the antistatic agent also includes carbon nanotubes, and the mass ratio of graphene oxide to carbon nanotubes is 7:1.

[0065] Example 6

[0066] The difference between Example 6 and Example 3 is that the antistatic agent also includes carbon nanotubes, and the mass ratio of graphene oxide to carbon nanotubes is 6:1.

[0067] Example 7

[0068] The difference between Example 7 and Example 6 is that the graphene oxide was prepared through modification. The modification and preparation method of graphene oxide includes the following steps:

[0069] 1g of graphene oxide was added to 100g of deionized water and stirred until homogeneous to obtain a graphene oxide dispersion. 12g of dodecylamine was added to 150g of anhydrous ethanol and stirred until homogeneous to obtain a dodecylamine solution. The graphene oxide dispersion and the dodecylamine solution were then mixed and stirred at 25°C for 24 hours. The mixture was then centrifuged with a mixture of deionized water and anhydrous ethanol (mass ratio of deionized water to anhydrous ethanol was 1:1) and freeze-dried to obtain modified graphene oxide.

[0070] Example 8

[0071] The difference between Example 8 and Example 6 is that the graphene oxide was prepared through modification. The method for preparing modified graphene oxide includes the following steps:

[0072] 1g of graphene oxide was added to 100g of deionized water and stirred until homogeneous to obtain a graphene oxide dispersion. 16g of dodecylamine was added to 150g of anhydrous ethanol and stirred until homogeneous to obtain a dodecylamine solution. The graphene oxide dispersion and the dodecylamine solution were then mixed and stirred at 25°C for 24 hours. The mixture was then centrifuged with a mixture of deionized water and anhydrous ethanol (mass ratio of deionized water to anhydrous ethanol was 1:1) and freeze-dried to obtain modified graphene oxide.

[0073] Example 9

[0074] The difference between Example 9 and Example 6 is that the graphene oxide was prepared through modification. The method for preparing modified graphene oxide includes the following steps:

[0075] 1g of graphene oxide was added to 100g of deionized water and stirred until homogeneous to obtain a graphene oxide dispersion. 14g of dodecylamine was added to 150g of anhydrous ethanol and stirred until homogeneous to obtain a dodecylamine solution. The graphene oxide dispersion and the dodecylamine solution were then mixed and stirred at 25°C for 24 hours. The mixture was then centrifuged with a mixture of deionized water and anhydrous ethanol (mass ratio of deionized water to anhydrous ethanol was 1:1) and freeze-dried to obtain modified graphene oxide.

[0076] Example 10

[0077] The difference between Example 10 and Example 9 is that the mass ratio of graphene oxide to dodecylamine is 1:10.

[0078] Example 11

[0079] The difference between Example 11 and Example 9 is that the mass ratio of graphene oxide to dodecylamine is 1:18.

[0080] Example 12

[0081] The difference between Example 12 and Example 9 is that glycidol is added during the graphene oxide modification process. The modified graphene oxide preparation method includes the following steps:

[0082] S100. Add 1g of graphene oxide to 100g of deionized water and stir until homogeneous to obtain a graphene oxide dispersion. Add 14g of dodecylamine to 150g of anhydrous ethanol and stir until homogeneous to obtain a dodecylamine solution. Mix the graphene oxide dispersion and the dodecylamine solution and stir at 25°C for 24h. Then centrifuge the mixture of deionized water and anhydrous ethanol (mass ratio of deionized water to anhydrous ethanol is 1:1) and freeze-dry to obtain primary modified graphene oxide.

[0083] S200: 100 mg of primary modified graphene oxide and 25 L of glycidol were mixed and stirred evenly. Then, nitrogen gas was introduced at 140 °C and stirred for 24 h to obtain a black mud-like substance. The black mud-like substance was then ultrasonically washed three times with 300 L of methanol. After natural precipitation, the supernatant was removed. Then, the mixture was heated to 75 °C, and 10 g of an ice-water solution of sodium borohydride (the mass concentration of the ice-water solution of sodium borohydride was 4%) was added dropwise to the solution. The mixture was stirred continuously for 3 h. The reaction solution was dialyzed in ultrapure water for 3 days to obtain an aqueous solution of hyperbranched polyglycerol modified graphene. After freeze-drying, modified graphene oxide was obtained.

[0084] Example 13

[0085] The difference between Example 13 and Example 12 is that polyvinylpyrrolidone is added in step S1.

[0086] That is: S1, 100g of nylon granules are dried, and then the dried nylon granules, 3g of antistatic agent and polyvinylpyrrolidone are mixed and melt-extruded at 250℃ to obtain a spinning melt.

[0087] Polyvinylpyrrolidone accounts for 2% of the mass of the antistatic agent.

[0088] Example 14

[0089] The difference between Example 14 and Example 13 is that the polyvinylpyrrolidone accounts for 4% of the mass of the antistatic agent.

[0090] Example 15

[0091] The difference between Example 15 and Example 13 is that polyvinylpyrrolidone accounts for 3% of the mass of the antistatic agent.

[0092] Example 16

[0093] The difference between Example 16 and Example 15 is that a metal salt is added in step S1.

[0094] That is: S1, 100g of nylon granules are dried, and then the dried nylon granules, 3g of antistatic agent, polyvinylpyrrolidone and metal salt are mixed and melt-extruded at 250℃ to obtain spinning melt.

[0095] The metal salt accounts for 0.5% of the mass of the nylon particles, and the metal salt is zinc chloride.

[0096] Example 17

[0097] The difference between Example 17 and Example 16 is that the metal salt accounts for 2% of the mass of the nylon particles.

[0098] Example 18

[0099] The difference between Example 18 and Example 16 is that the metal salt accounts for 1.2% of the mass of the nylon particles.

[0100] Comparative Example 1

[0101] The difference between Comparative Example 1 and Example 1 is that no antistatic agent is added during the production of high-shrinkage nylon.

[0102] Performance testing:

[0103] Samples (equal length samples) of the nylon fibers prepared in Examples 1-18 and Comparative Example 1 were taken, boiled at the same temperature for 30 minutes, dried, and equilibrated for 2 hours. The lengths of the three samples were then measured, and the boiling water shrinkage rate was calculated as follows: Boiling water shrinkage rate = (length of sample before boiling - length of sample after boiling) / length of sample before boiling * 100%. The results are recorded in Table 1.

[0104] Table 1

[0105]

[0106]

[0107] Data Analysis

[0108] Specifically, considering the experimental results of Examples 4-6 and Example 3, the shrinkage of Examples 4-6 is better than that of Example 3. The analysis is as follows: the difference between Examples 4-6 and Example 3 is that the antistatic agent contains not only graphene oxide but also carbon nanotubes. On the one hand, carbon nanotubes have good conductivity; on the other hand, carbon nanotubes can reduce the aggregation of graphene oxide and increase the compatibility between graphene oxide, carbon nanotubes and nylon particles, thereby improving the conductivity of nylon fibers, reducing electrostatic deposition, and thus improving the shrinkage of nylon fibers.

[0109] Specifically, based on the experimental results of Examples 7-9 and Example 6, the shrinkage of Examples 7-9 is better than that of Example 6. The analysis is as follows: the difference between Examples 7-9 and Example 6 is that the graphene oxide is modified by dodecylamine, which improves the interfacial compatibility between graphene oxide and nylon particles, thereby improving the stability of graphene oxide in the nylon matrix and thus improving the shrinkage of nylon fibers.

[0110] Specifically, based on the experimental results of Examples 12 and 9, the shrinkage of Example 12 is better than that of Example 9. The analysis is as follows: the difference between Example 12 and Example 9 is that glycidol is added during the graphene oxide modification process, which improves the hydrophilicity of graphene oxide, thereby improving the moisture absorption of nylon fiber and thus improving the shrinkage of nylon fiber.

[0111] Specifically, based on the experimental results of Examples 13-15 and Example 12, the shrinkage of Example 13-15 is better than that of Example 12. The analysis is as follows: the difference between Example 13-15 and Example 12 is that polyvinylpyrrolidone is added during the preparation of nylon fiber. On the one hand, polyvinylpyrrolidone can improve the shrinkage of nylon fiber, and on the other hand, it can improve the conductivity and hydrophilicity of carbon nanotubes, thereby improving the shrinkage of nylon fiber.

[0112] Specifically, based on the experimental results of Examples 16-18 and Example 15, the shrinkage of Example 16-18 is better than that of Example 15. The analysis is as follows: the difference between Example 16-18 and Example 15 is that metal salts are added during the preparation of nylon fibers, which can effectively reduce crystallinity and thus improve the shrinkage of nylon fibers.

[0113] Specifically, based on the experimental results of Example 1 and Comparative Example 1, the shrinkage of Example 1 is better than that of Comparative Example 1. The analysis is as follows: the difference between Example 1 and Comparative Example 1 is that graphene oxide is added during the preparation of nylon fiber. Graphene oxide has good conductivity, which can effectively improve the conductivity of nylon fiber, reduce electrostatic deposition, and thus improve the shrinkage rate of nylon fiber.

[0114] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high-shrinkage nylon production process, characterized in that: Includes the following steps: S1. The nylon granules are dried, and then the dried nylon granules are mixed with an antistatic agent and melt-extruded to obtain a spinning melt. S2. The spinning melt is spun into composite fibers, and then stretched to obtain nylon fibers. The antistatic agent includes graphene oxide; The antistatic agent also includes carbon nanotubes; The graphene oxide is obtained through modification, and the modification preparation method of the graphene oxide includes the following steps: Graphene oxide was added to deionized water and stirred evenly to obtain a graphene oxide dispersion. Dodecylamine was added to anhydrous ethanol and stirred evenly to obtain a dodecylamine solution. The graphene oxide dispersion and the dodecylamine solution were then mixed and stirred evenly. After centrifugation and washing, and freeze-drying, modified graphene oxide was obtained. The mass ratio of the nylon granules to the antistatic agent is 1:(0.04-0.06). The mass ratio of graphene oxide to carbon nanotubes is (5-7):1; In step S1, polyvinylpyrrolidone is also added. The specific steps of step S1 are as follows: The nylon granules are dried, and then the dried nylon granules, antistatic agent, and polyvinylpyrrolidone are mixed and melt-extruded to obtain a spinning melt. The polyvinylpyrrolidone accounts for (2-4)% of the mass of the antistatic agent; In step S1, a metal salt is also added. The specific steps of step S1 are as follows: The nylon granules are dried, and then the dried nylon granules, antistatic agent, polyvinylpyrrolidone, and metal salt are mixed and melt-extruded to obtain a spinning melt. The metal salt accounts for (0.5-2)% of the mass of the nylon particles. The metal salt is zinc chloride.

2. The high-shrinkage nylon production process according to claim 1, characterized in that: The mass ratio of graphene oxide to dodecylamine is 1:(12-16).

3. The high-shrinkage nylon production process according to claim 1, characterized in that: The modification process of the graphene oxide also involves the addition of glycidol, i.e., the modified graphene oxide preparation method includes the following steps: S100. Add graphene oxide to deionized water and stir evenly to obtain graphene oxide dispersion. Add dodecylamine to anhydrous ethanol and stir evenly to obtain dodecylamine solution. Mix the graphene oxide dispersion and dodecylamine solution and stir evenly. Then centrifuge and wash, freeze dry, and obtain primary modified graphene oxide. S200. Primary modified graphene oxide and glycidol are mixed and stirred evenly. Nitrogen gas is then introduced and stirred under heating conditions to obtain a black mud-like substance. The black mud-like substance is then washed with methanol, allowed to precipitate naturally, and the supernatant is removed. The precipitate is then dialyzed in ultrapure water and heated. An ice-water solution of sodium borohydride is added and stirred evenly. The reaction solution is then dialyzed in ultrapure water and freeze-dried to obtain modified graphene oxide.

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