A bicomponent fiber and a method for producing the same

Abstract

The application relates to a kind of bicomponent fibers and its preparation method, polyester melt and polyamide melt are extruded from spinneret after parallel extrusion, and then the nascent fiber is obtained by side blowing cooling, then the nascent fiber is heated by heat pipe in turn, oiled, pre-network, three-roll drafting heat setting, winding, so that bicomponent fiber is prepared;Heat pipe is used to heat nascent fiber, and the temperature of heat pipe is 90~100 DEG C;Three rollers include first hot roller, second hot roller and third hot roller;The temperature of first hot roller is 70~90 DEG C, the temperature of second hot roller is 110~130 DEG C, and the temperature of third hot roller is 140~160 DEG C;The single filament fineness of prepared bicomponent fiber is 2.6~3.5 dtex, breaking strength is greater than or equal to 3.23 cN / dtex, elongation at break is 27.45~38.31%, and the number of broken ends is less than or equal to 2.3 times per (48 positions·24 hours), and the hairiness rate is stably controlled below 0.30%.The preparation method of the application greatly reduces the generation of internal stress;The mechanical properties of bicomponent fiber are improved, and the number of broken ends and hairiness rate of fiber are significantly reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of composite fibers, and relates to a bicomponent fiber and a preparation method thereof. BACKGROUND

[0002] In the field of co-spun or mixed filaments, there are many commonly used methods for producing co-spun or mixed filaments, such as parallel yarns, post-processing front plying mixed filaments, post-processing rear plying mixed filaments, etc. With the development of domestic composite spinning technology, composite co-spun filaments are increasingly favored by people due to their advanced technology, maneuverability, flexibility, economic rationality, and good simulation effect. At present, composite co-spun filaments are a process in which multiple raw material chips are respectively melted and extruded by a screw extruder, and then sprayed out of different holes of the same composite spinning assembly. Among them, the ratio of raw materials or components can be various, and can be the same or different types of polymer raw materials. Polyester and nylon are the two highest-yielding fibers in synthetic fibers, and due to their unique properties, they are widely used in civilian and industrial fields. With the improvement of people's demand for life quality, single-component fibers with single function have gradually lost market momentum, and are replaced by composite and functional fibers. Among them, composite fibers can be divided into two types: bicomponent composite fibers and multicomponent composite fibers, which have the characteristics of different components of polymers and unique properties of composite fibers.

[0003] In the production process of bicomponent fibers composed of polyester and nylon, the flow rates of the bicomponent polymer melts extruded from the spinneret holes are inconsistent. Different regions with fast and slow flow rates will have different stretching and shrinking conditions during the subsequent solidification process, which will cause uneven molecular arrangement and generate internal stress. In the cooling process, uneven cooling will also cause thermal stress. In addition, due to the difference in thermal properties of bicomponents, the internal stress increases rapidly and is distributed unevenly during the stretching process. The existence of internal stress and thermal stress will result in a high number of broken ends and a high rate of lint.

[0004] Patent CN110644073B discloses a preparation method of polyester-nylon side-by-side composite elastic fiber, which uses PET chips and nylon 6 chips as two components, and then uses a specially designed skin-core type composite spinneret to produce the polyester-nylon side-by-side composite elastic fiber. The cross-section of the polyester-nylon side-by-side composite elastic fiber is dumbbell-shaped, with a nylon 6 layer covering one side of the polyester component, which makes it difficult for PA6 and PET to open fiber, and the stress distribution is improved by inducing self-curling using the difference in thermal shrinkage of the two components. However, the polyester-nylon composite fiber prepared by the method of the patent has excellent elasticity, but due to the uneven distribution of polyester and nylon in the single fiber, the strength of the single fiber is uneven and depends on the physical structure to disperse stress. During the stretching process, stress is easily concentrated in the weak part of the internal stress distribution, leading to frequent broken ends.

[0005] Therefore, it is of great significance to study a bicomponent fiber and a preparation method thereof to solve the above problems. SUMMARY

[0006] The application aims to solve the problems in the prior art and provide a bicomponent fiber and a preparation method thereof.

[0007] To achieve the above object, the technical scheme adopted by the application is as follows:

[0008] A preparation method of a bicomponent fiber, wherein polyester melt and polyamide melt are extruded from a spinneret in parallel, and then the as-spun fiber is obtained through side-blowing cooling, and then the as-spun fiber is sequentially subjected to heating by a heat pipe, oiling, pre-networking, three-roll drafting and heat setting, and winding to obtain the bicomponent fiber.

[0009] The heat pipe is used for heating the as-spun fiber, and the temperature of the heat pipe is 90-100℃. When the temperature of the heat pipe is greater than or equal to 90℃, the polyester and the polyamide in the fiber are both higher than the glass transition temperature, and the molecular chain segments of the fiber can start to move, so that the movement and rearrangement of the chain segments occur. When the temperature of the heat pipe is less than or equal to 100℃, the polyester and the polyamide in the fiber are not in a molten state.

[0010] The three rolls include a first hot roll, a second hot roll and a third hot roll. The temperature of the first hot roll is 70-90℃, the temperature of the second hot roll is 110-130℃, and the temperature of the third hot roll is 140-160℃.

[0011] In the fiber spinning process, the polyester melt and the polyamide melt extruded from the spinneret are in a high-temperature state. The flow rates of the bicomponent polymer melt (i.e. the polyester melt and the polyamide melt) extruded from the spinneret are inconsistent. In the subsequent solidification process, the areas with fast flow rate and the areas with slow flow rate will have different stretching and shrinking conditions, which will cause uneven molecular arrangement and thus internal stress. The temperature of the heat pipe heating can make the fiber molecular chains rearrange and adjust, thereby reducing the internal stress caused by uneven molecular chain arrangement and imperfect crystallization.

[0012] In terms of thermal stress, the heat pipe can heat the fiber uniformly and quickly as a whole, avoid uneven thermal expansion caused by local overheating or overcooling, and eliminate thermal stress.

[0013] The three-roll drafting of the prior art is usually used to draft single-component yarns, the first roll is used for pre-orientation, the second roll is used for crystallization, and the third roll is used for heat setting. When facing bicomponent fibers, due to the thermal performance difference of bicomponents, the temperature parameters of the three rolls in the prior art cannot be adapted to bicomponent fibers, so that the internal stress of the two components cannot be effectively released, resulting in weak bonding force at the interface, affecting the mechanical properties of the bicomponent fibers. The temperature of the three rolls set in the application is that the temperature of the first roll is 70-90℃, the two components are preliminarily oriented, the temperature of the second roll is 110-130℃, which matches the crystallization temperature of polyamide, and at the same time, the polyester is further relaxed, because the polyester crystallization needs a higher temperature, the temperature of the third roll is 140-160℃, which accurately corresponds to the crystallization temperature of polyester, and at the same time, the polyamide is further set: the staged crystallization makes the internal stress of the two components have a gradient buffer inside the fiber to avoid local stress concentration, fundamentally reducing the source and accumulation opportunities of internal stress.

[0014] In summary, the use of heat pipe + hot roll optimizes the double thermal stress and internal stress of the fiber, improves the mechanical properties of the fiber, and reduces the number of broken ends and the rate of hairiness of the fiber.

[0015] As a preferred technical solution:

[0016] The preparation method of the bicomponent fiber described above, the heat pipe comprises a shell and an inner tube; the shell is a hollow cubic structure; the upper surface of the shell is provided with a cylindrical through hole I, and the lower surface is provided with a cylindrical through hole II, the inner diameters of the cylindrical through hole I and the cylindrical through hole II are the same; the centers of the cylindrical through hole I and the cylindrical through hole II are on the same central axis; the inner tube is arranged in the shell, and the inner tube is located directly below the spinneret; the upper end of the inner tube is connected with the cylindrical through hole I, and the lower end is connected with the cylindrical through hole II, so that the inner tube and the shell form a jacket structure; the jacket is used to pass in 90-100℃ biphenyl-biphenyl ether to heat the inner tube.

[0017] The preparation method of the bicomponent fiber described above, the distance between the upper end of the inner tube and the spinneret is 50cm, and the length of the inner tube is 100cm. Under the condition of side blowing cooling, the 50cm distance can reduce the influence of the low temperature area below the spinneret on the melt, prevent the premature solidification of the yarn surface, and avoid uneven internal stress. The length of the heat pipe is 100cm, which can realize the high-efficiency heat transfer demand of the heat pipe.

[0018] The preparation method of the bicomponent fiber described above, the inner tube, the cylindrical through hole I and the cylindrical through hole II are the same as the number of the spinneret, and one-to-one correspondence.

[0019] The preparation method of the bicomponent fiber described above, the mass ratio of the polyester melt and the polyamide melt is 40-60:60-40.

[0020] The raw material of the polyamide melt comprises polyamide chips, nano-mica masterbatch, antioxidant and dispersant.

[0021] The addition amount of the antioxidant is 0.1-1 wt% of the polyamide melt, the addition amount of the dispersant is 0.1-1 wt% of the polyamide melt, and the addition amount of the nano-mica masterbatch is 4-6 wt% of the polyamide melt.

[0022] The nano-mica masterbatch can provide cool feeling function and increase color effect, but introduction into the polyamide chips will cause oxidation of the polyamide chips as impurities, so the antioxidant and the dispersant need to be added at the same time to overcome the above problems.

[0023] The raw material of the polyamide melt comprises polyamide chips, nano-mica masterbatch, antioxidant and dispersant.

[0024] The mica has a flaky crystal structure, and the crystal morphology can form a kind of "skeleton" support structure inside the fiber, and the dispersant prevents the agglomeration of the nano-mica, so that it is uniformly dispersed in the fiber matrix, and the stress can be more uniformly dispersed in the whole fiber, so as to enhance the toughening effect and reduce stress concentration.

[0025] The raw material of the polyamide melt comprises polyamide chips, nano-mica masterbatch, antioxidant and dispersant.

[0026] The oil agent used for the oiling comprises a polyamide chain extender, preferably the polyamide chain extender is an epoxy chain extender, and the addition amount of the polyamide chain extender is 1-3% of the total mass of the oil agent. The polyamide chain extender in the oil agent can connect different polyamide polymer chain segments in the polyamide fiber, so that the fiber can bear higher internal stress when stretched, enhance the dimensional stability of the high-strength and low-elongation polyamide fiber, and have high-temperature and anti-oxidation aging functions.

[0027] The process parameters further comprise side blowing temperature of 20-30℃, side blowing speed of 0.30-0.60 m / s, side blowing humidity of 75±5%, draft ratio of 2.5-3.0, and winding speed of 3800-4500 m / min.

[0028] The application further provides the bicomponent fiber prepared by the preparation method, and the monofilament fineness of the prepared bicomponent fiber is 2.6-3.5 dtex, the breaking strength is greater than or equal to 3.23 cN / dtex, the breaking elongation is 27.45-38.31%, and the breakage frequency is less than or equal to 2.3 times per 48 positions per 24 hours, and the fuzz rate is stably controlled below 0.30%.

[0029] Advantages:

[0030] (1) The temperature of the heat pipe heating in the preparation method of the bicomponent fiber can make the molecular chains of the fiber rearrange and adjust, so as to reduce the internal stress caused by uneven molecular chain arrangement and imperfect crystallization; meanwhile, the internal stress of the two components has a gradient buffer in the fiber through the setting of the three-roller temperature, so as to avoid local stress concentration, and fundamentally reduce the source and accumulation opportunities of the internal stress.

[0031] (2) The bicomponent fiber prepared by the preparation method has improved mechanical properties, and the breakage frequency and the fuzz rate of the fiber are obviously reduced. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a schematic diagram of the use state of the heat pipe of the application;

[0033] In the formula, 1 is a shell, 2 is an inner tube, and 3 is a biphenyl-biphenyl ether. DETAILED DESCRIPTION

[0034] The application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not used to limit the scope of the application. In addition, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope defined by the claims of the application.

[0035] The test methods involved in the performance indicators in the examples and comparative examples of the application are as follows:

[0036] Breaking strength and breaking elongation: the test is performed according to the standard GB / T 14344-2008.

[0037] Breakage frequency: the breakage refers to the sudden breakage of the monofilament during spinning, and when 1 spinning position breaks, it is recorded as 1 time. A statistical cycle is 10 days and 48 positions, and the breakage frequency of 48 positions per 24 hours is calculated according to the average value.

[0038] Fuzz rate: the fuzz rate of the fiber is tested according to the industry standard FZ / T 50054-2021 “Chemical Fiber Filament Winding Appearance Online Intelligent Detection”.

[0039] The sources of some substances in the application are as follows:

[0040] Nano-mica masterbatch: manufacturer: Suzhou Chengwei Nanotechnology Co., Ltd., brand: carrier-free mica particles.

[0041] Epoxy chain extender: manufacturer: BASF, brand: Joncryl® ADR-4468.

[0042] Biphenyl-biphenyl ether: manufacturer: Suzhou Huanghai Heat Transfer Oil Co., Ltd., brand: Leetherm 240.

[0043] Example 1

[0044] A method for preparing a bicomponent fiber, the specific steps are as follows:

[0045] (1) Preparation of raw materials:

[0046] Polyester melt: the corresponding raw material is polyester chip, and the intrinsic viscosity of the polyester chip is 0.60 dL / g;

[0047] Polyamide melt: the corresponding raw material is composed of polyamide chip, nano-mica masterbatch, antioxidant and PE wax (manufacturer: Honeywell, brand: AC-617A); the intrinsic viscosity of the polyamide chip is 3.0 dL / g;

[0048] Among them, the antioxidant is antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1; the addition amount of the antioxidant is 0.5wt% of the polyamide melt, the addition amount of the PE wax is 0.5wt% of the polyamide melt, and the addition amount of the nano-mica masterbatch is 4wt% of the polyamide melt;

[0049] (2) After the polyester melt and the polyamide melt with a mass ratio of 40:60 are extruded side by side from the spinneret, the as-spun fiber is obtained by passing through the side blowing cooling, and then the as-spun fiber sequentially passes through the heat pipe heating, the oiling, the pre-networking, the three-roll drafting heat setting and the winding to prepare the bicomponent fiber;

[0050] As shown in Figure 1 , the heat pipe is used for heating the as-spun fiber; the heat pipe includes a shell 1 and an inner tube 2; the shell 1 is a hollow cubic structure; the upper surface of the shell 1 is provided with a cylindrical through hole I, and the lower surface is provided with a cylindrical through hole II; the inner diameters of the cylindrical through hole I and the cylindrical through hole II are the same; the centers of the cylindrical through hole I and the cylindrical through hole II are on the same central axis; the inner tube 2 is arranged in the shell 1, and the inner tube 2 is located directly below the spinneret; the upper end of the inner tube 2 is connected with the cylindrical through hole I, and the lower end is connected with the cylindrical through hole II, so that the inner tube 2 and the shell 1 form a jacket structure; the jacket is used for introducing 100℃ biphenyl-biphenyl ether 3 to heat the inner tube 2;

[0051] The distance between the upper end of the inner tube 2 and the spinneret is 50 cm, and the length of the inner tube 2 is 100 cm;

[0052] The inner tube 2, the cylindrical through hole I and the cylindrical through hole II are the same in number as the spinneret and one-to-one corresponding;

[0053] The process parameters are as follows:

[0054] The three rollers include a first hot roller, a second hot roller and a third hot roller; the temperature of the first hot roller is 90℃, the temperature of the second hot roller is 130℃, and the temperature of the third hot roller is 160℃;

[0055] The oil used for oiling is composed of 1wt% epoxy chain extender and 99wt% D972 oil agent of DAKO brand;

[0056] The side blowing temperature is 30℃, the side blowing speed is 0.6m / s, the side blowing humidity is 75%, the draft ratio is 2.5, and the winding hot roller speed is 4500m / min.

[0057] The final prepared bicomponent fiber has a filament fineness of 2.6dtex, a breaking strength of 3.23cN / dtex, an elongation at break of 38.31%, a number of breakage of 2.3 times / (48 positions·24 hours), and a hairiness rate of 0.30%.

[0058] Comparative Example 1

[0059] A method for preparing a bicomponent fiber, which is basically the same as Example 1, except that the temperature of the hot tube is 70℃.

[0060] The final prepared bicomponent fiber has a breaking strength of 2.85cN / dtex, an elongation at break of 43.16%, a number of breakage of 9.6 times / (48 positions·24 hours), and a hairiness rate of 0.83%.

[0061] Comparing Comparative Example 1 and Example 1, it can be found that the breaking strength of the bicomponent fiber finally prepared in the comparative example is significantly reduced, and the elongation at break, the number of breakage and the hairiness rate are increased more, which is because the temperature of the hot tube is too low, which is lower than the glass transition temperature of polyester and higher than the glass transition temperature of polyamide. In theory, the temperature of the polyamide molecular chain is above the glass transition temperature, and the chain segment of the polyamide molecular chain can move, but the temperature of the polyester molecular chain is below the glass transition temperature, and the chain segment of the polyester molecular chain is insufficient. Therefore, the polyester chain segment, which is relatively strong in rigidity, restricts the polyamide molecular chain, resulting in significant restriction of the movement and rearrangement of the chain segment in the fiber, leading to uneven crystallization and orientation, thereby affecting the breaking strength, elongation at break, number of breakage and hairiness rate of the fiber.

[0062] Comparative Example 2

[0063] A method for preparing a bicomponent fiber, which is substantially the same as that of Example 1, except that the temperature of the hot tube is 105℃.

[0064] The bicomponent fiber finally prepared has a breaking strength of 3.07 cN / dtex, an elongation at break of 39.20%, a number of breakage of 7.8 times / (48 positions·24 hours), and a hairiness rate of 0.58%.

[0065] Comparing Example 1 with Comparative Example 2, it can be found that the breaking strength of the bicomponent fiber finally prepared in Comparative Example 2 is significantly reduced, and the elongation at break, the number of breakage and the hairiness rate are increased more, which is because the temperature of the hot tube is too high, leading to excessive relaxation and disorientation of molecular chain segments, thereby affecting the breaking strength, the elongation at break, the number of breakage and the hairiness rate of the fiber.

[0066] Comparative Example 3

[0067] A method for preparing a bicomponent fiber, which is substantially the same as that of Example 1, except that the temperature of the first hot roller is 90℃, the temperature of the second hot roller is 140℃, and the temperature of the third hot roller is 160℃.

[0068] The bicomponent fiber finally prepared has a breaking strength of 2.89 cN / dtex, an elongation at break of 40.42%, a number of breakage of 9.1 times / (48 positions·24 hours), and a hairiness rate of 1.20%.

[0069] Comparing Example 1 with Comparative Example 3, it can be found that the breaking strength of the bicomponent fiber finally prepared in Comparative Example 3 is significantly reduced, and the elongation at break, the number of breakage and the hairiness rate are increased more, which is because the temperature of the second hot roller is too high, and the polyamide and the polyester cannot crystallize in stages, so that the internal stress of the bicomponent cannot be effectively released, leading to weak binding force at the interface, thereby affecting the mechanical properties of the fiber.

[0070] Example 2

[0071] A method for preparing a bicomponent fiber, the specific steps of which are as follows:

[0072] (1) Preparation of raw materials:

[0073] Polyester melt: the corresponding raw material is polyester chips, and the intrinsic viscosity of the polyester chips is 0.62 dL / g;

[0074] Polyamide melt: the corresponding raw material is composed of polyamide chips, nano-mica masterbatch, antioxidant and PE wax (manufacturer: Honeywell, brand: AC-617A); the intrinsic viscosity of the polyamide chips is 3.2 dL / g;

[0075] The antioxidant is antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; the addition amount of the antioxidant is 0.3 wt% of the polyamide melt; the addition amount of the PE wax is 0.2 wt% of the polyamide melt; and the addition amount of the nano-mica master batch is 5.0 wt% of the polyamide melt;

[0076] (2) the polyester melt and the polyamide melt in a mass ratio of 50:50 are extruded from the spinneret in parallel, and then the nascent fibers are obtained by side-blowing cooling, and then the nascent fibers are sequentially subjected to heating by a heat pipe, oiling, pre-networking, three-roll drafting heat setting and winding to obtain the bicomponent fibers;

[0077] The heat pipe is used for heating the nascent fibers; the heat pipe comprises a shell and an inner pipe; the shell has a hollow cubic structure; the upper surface of the shell is provided with a cylindrical through hole I, and the lower surface of the shell is provided with a cylindrical through hole II, the inner diameters of the cylindrical through hole I and the cylindrical through hole II are the same; the centers of the cylindrical through hole I and the cylindrical through hole II are on the same central axis; the inner pipe is arranged in the shell and located directly below the spinneret; the upper end of the inner pipe is connected with the cylindrical through hole I, and the lower end of the inner pipe is connected with the cylindrical through hole II, so that the inner pipe and the shell form a jacket structure; the jacket is used for introducing 90℃ biphenyl-biphenyl ether to heat the inner pipe;

[0078] The distance between the upper end of the inner pipe and the spinneret is 50cm, and the length of the inner pipe is 100cm;

[0079] The number of the inner pipe, the cylindrical through hole I and the cylindrical through hole II is the same as that of the spinneret, and each of them corresponds to one spinneret;

[0080] The process parameters are as follows:

[0081] The three rollers comprise a first hot roller, a second hot roller and a third hot roller; the temperature of the first hot roller is 70℃, the temperature of the second hot roller is 110℃, and the temperature of the third hot roller is 140℃;

[0082] The oil agent used for oiling is composed of 2wt% epoxy chain extender and 98wt% D972 oil agent of DAKO brand;

[0083] The temperature of the side-blowing air is 20℃, the speed of the side-blowing air is 0.5m / s, the humidity of the side-blowing air is 75%, the drafting multiple is 2.8, and the speed of the winding hot roller is 4200m / min.

[0084] The final bicomponent fibers have a filament fineness of 2.8dtex, a breaking strength of 3.35cN / dtex, an elongation at break of 32.29%, a number of breakage of 2.1 times / (48 positions·24 hours) and a lint rate of 0.20%.

[0085] Example 3

[0086] A method for preparing a bicomponent fiber, the specific steps are as follows:

[0087] (1) Preparation of raw materials:

[0088] Polyester melt: the corresponding raw material is polyester chip, and the intrinsic viscosity of the polyester chip is 0.65 dL / g;

[0089] Polyamide melt: the corresponding raw material is composed of polyamide chip, nano-mica master batch, antioxidant and PE wax (manufacturer: Honeywell, brand: AC-617A); the intrinsic viscosity of the polyamide chip is 3.4 dL / g;

[0090] Among them, the antioxidant is antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1; the addition amount of the antioxidant is 0.1wt% of the polyamide melt, the addition amount of the PE wax is 0.1wt% of the polyamide melt, and the addition amount of the nano-mica master batch is 6.0wt% of the polyamide melt;

[0091] (2) After the polyester melt and the polyamide melt with a mass ratio of 60:40 are extruded from the spinneret in parallel, the nascent fiber is obtained by side blowing and cooling, and then the nascent fiber sequentially passes through a heat pipe heating, oiling, pre-networking, three-roll drafting and heat setting, and winding to obtain a bicomponent fiber;

[0092] The heat pipe is used for heating the nascent fiber; the heat pipe comprises a shell and an inner tube; the shell is a hollow cubic structure; the upper surface of the shell is provided with a cylindrical through hole I, and the lower surface is provided with a cylindrical through hole II; the inner diameters of the cylindrical through hole I and the cylindrical through hole II are the same; the centers of the cylindrical through hole I and the cylindrical through hole II are on the same central axis; the inner tube is arranged in the shell, and the inner tube is located directly below the spinneret; the upper end of the inner tube is connected with the cylindrical through hole I, and the lower end is connected with the cylindrical through hole II, so that the inner tube and the shell form a jacket structure; the jacket is used for introducing 95℃ biphenyl-biphenyl ether to heat the inner tube;

[0093] The distance between the upper end of the inner tube and the spinneret is 50cm, and the length of the inner tube is 100cm;

[0094] The number of the inner tube, the cylindrical through hole I and the cylindrical through hole II is the same as that of the spinneret, and they are one-to-one corresponding;

[0095] The process parameters are as follows:

[0096] The three rollers include a first hot roller, a second hot roller and a third hot roller; the temperature of the first hot roller is 80℃, the temperature of the second hot roller is 120℃, and the temperature of the third hot roller is 150℃;

[0097] The oil agent used for oiling is composed of 3wt% epoxy chain extender and 97wt% D972 oil agent of DAKO brand;

[0098] The side blowing air temperature is 25℃, the side blowing air speed is 0.3m / s, the side blowing air humidity is 75%, the draft ratio is 3, and the winding hot roller speed is 3800m / min.

[0099] The final bicomponent fiber has a single filament fineness of 3.5dtex, a breaking strength of 3.48cN / dtex, a breaking elongation of 27.56%, a breaking frequency of 1.8times / (48positions*24hours), and a fuzzy yarn rate of 0.15%.

[0100] Example 4

[0101] A preparation method of a bicomponent fiber, and the specific steps are as follows:

[0102] (1) Preparation of raw materials:

[0103] The corresponding raw material of the polyester melt is a polyester chip, and the intrinsic viscosity of the polyester chip is 0.61dL / g;

[0104] The corresponding raw material of the polyamide melt is composed of a polyamide chip, a nano-mica master batch, an antioxidant, and an ethylene oxide-propylene oxide block copolymer ether oligomer (manufacturer: BASF, brand: Pluronic PE 6400); the intrinsic viscosity of the polyamide chip is 3.1dL / g;

[0105] The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; the addition amount of the antioxidant is 0.8wt% of the polyamide melt, the addition amount of the ethylene oxide-propylene oxide block copolymer ether oligomer is 0.9wt% of the polyamide melt, and the addition amount of the nano-mica master batch is 4.5wt% of the polyamide melt;

[0106] (2) After the polyester melt and the polyamide melt in a mass ratio of 45:55 are extruded from the spinneret in parallel, the as-spun fiber is obtained by side blowing cooling, and then the as-spun fiber sequentially passes through a heat pipe heating, oiling, pre-networking, three-roll drafting, heat setting, and winding to obtain the bicomponent fiber;

[0107] The heat pipe is used for heating the as-spun fiber; the heat pipe comprises a shell and an inner tube; the shell has a hollow cubic structure; the upper surface of the shell is provided with a cylindrical through hole I, and the lower surface of the shell is provided with a cylindrical through hole II, and the inner diameters of the cylindrical through hole I and the cylindrical through hole II are the same; the centers of the cylindrical through hole I and the cylindrical through hole II are on the same central axis; the inner tube is arranged in the shell, and the inner tube is located directly below the spinneret; the upper end of the inner tube is connected with the cylindrical through hole I, and the lower end of the inner tube is connected with the cylindrical through hole II, so that the inner tube and the shell form a jacket structure; the jacket is used for introducing 100℃ biphenyl-biphenyl ether to heat the inner tube;

[0108] The distance between the upper end of the inner tube and the spinneret is 50 cm, and the length of the inner tube is 100 cm;

[0109] The inner tube, the cylindrical through hole I and the cylindrical through hole II are the same in number as the spinneret and one-to-one corresponding;

[0110] The process parameters are as follows:

[0111] The three rollers include a first hot roller, a second hot roller and a third hot roller; the temperature of the first hot roller is 90℃, the temperature of the second hot roller is 130℃, and the temperature of the third hot roller is 160℃;

[0112] The oil used for oiling is composed of 1.5wt% epoxy chain extender and 98.5wt% D972 oil agent of DAKO brand;

[0113] The side blowing temperature is 30℃, the side blowing speed is 0.6m / s, the side blowing humidity is 75%, the draft ratio is 2.5, and the winding hot roller speed is 4500m / min.

[0114] The final prepared bicomponent fiber has a filament fineness of 2.6dtex, a breaking strength of 3.25cN / dtex, an elongation at break of 37.29%, a number of breakage times of 2.2 times / (48 positions·24 hours), and a lint rate of 0.23%.

[0115] Example 5

[0116] A preparation method of a bicomponent fiber, the specific steps are as follows:

[0117] (1) Preparation of raw materials:

[0118] The corresponding raw material of the polyester melt is a polyester chip, and the intrinsic viscosity of the polyester chip is 0.63dL / g;

[0119] The corresponding raw material of the polyamide melt is composed of a polyamide chip, a nano-mica master batch, an antioxidant and an ethylene oxide-propylene oxide block copolymer (the manufacturer of the ethylene oxide-propylene oxide block copolymer is BASF, and the model is Pluronic PE 6400); the intrinsic viscosity of the polyamide chip is 3.3dL / g;

[0120] The antioxidant is antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; the addition amount of the antioxidant is 0.4wt% of the polyamide melt, the addition amount of the ethylene oxide-propylene oxide block copolymer is 0.4wt% of the polyamide melt, and the addition amount of the nano-mica master batch is 5.5wt% of the polyamide melt;

[0121] (2) the bicomponent fiber is prepared by parallel extruding polyester melt and polyamide melt with a mass ratio of 55:45 from a spinneret, cooling the as-spun fiber by side-blowing, and then sequentially heating the as-spun fiber by a heat pipe, oiling, pre-networking, three-roll drafting, heat setting and winding;

[0122] The heat pipe is used for heating the as-spun fiber; the heat pipe comprises a shell and an inner pipe; the shell has a hollow cubic structure; the upper surface of the shell is provided with a cylindrical through hole I, and the lower surface of the shell is provided with a cylindrical through hole II, the inner diameters of the cylindrical through hole I and the cylindrical through hole II are the same; the centers of the cylindrical through hole I and the cylindrical through hole II are on the same central axis; the inner pipe is arranged in the shell and located directly below the spinneret; the upper end of the inner pipe is connected with the cylindrical through hole I, and the lower end of the inner pipe is connected with the cylindrical through hole II, so that the inner pipe and the shell form a jacket structure; the jacket is used for introducing 90 DEG C biphenyl-biphenyl ether to heat the inner pipe;

[0123] The distance between the upper end of the inner pipe and the spinneret is 50 cm, and the length of the inner pipe is 100 cm;

[0124] The number of the inner pipe, the cylindrical through hole I and the cylindrical through hole II is the same as that of the spinneret, and each of them corresponds to one spinneret;

[0125] The process parameters are as follows:

[0126] The three rolls comprise a first hot roll, a second hot roll and a third hot roll; the temperature of the first hot roll is 70 DEG C, the temperature of the second hot roll is 110 DEG C, and the temperature of the third hot roll is 140 DEG C;

[0127] The oil agent used for oiling is composed of 2.5wt% epoxy chain extender and 97.5wt% D972 oil agent of DAKO brand;

[0128] The temperature of the side-blowing is 20 DEG C, the speed of the side-blowing is 0.5 m / s, the humidity of the side-blowing is 75%, the drafting multiple is 2.8, and the speed of the winding hot roll is 4200 m / min.

[0129] The final bicomponent fiber has a filament fineness of 2.8 dtex, a breaking strength of 3.40 cN / dtex, an elongation at break of 31.22%, a number of breakage of 1.9 times / (48 positions*24 hours) and a lint rate of 0.18%.

[0130] Example 6

[0131] A preparation method of a bicomponent fiber, and the specific steps are as follows:

[0132] (1) Preparation of raw materials:

[0133] The polyester melt corresponds to a polyester chip, and the intrinsic viscosity of the polyester chip is 0.65 dL / g;

[0134] Polyamide melt: the corresponding raw material is composed of polyamide chips, nano-mica masterbatch, antioxidant and ethylene oxide-propylene oxide block copolymer ether oligomer (manufacturer: BASF, brand: Pluronic PE 6400); the intrinsic viscosity of the polyamide chips is 3.4 dL / g;

[0135] The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; the addition amount of the antioxidant is 1.0 wt% of the polyamide melt, the addition amount of the ethylene oxide-propylene oxide block copolymer ether oligomer is 1.0 wt% of the polyamide melt, and the addition amount of the nano-mica masterbatch is 6.0 wt% of the polyamide melt;

[0136] (2) After the polyester melt and the polyamide melt with a mass ratio of 60:40 are extruded from the spinneret in parallel, the nascent fiber is obtained by side-blowing cooling, and then the nascent fiber sequentially passes through a heat pipe heating, oiling, pre-networking, three-roll drafting heat setting and winding to obtain a bicomponent fiber;

[0137] The heat pipe is used for heating the nascent fiber; the heat pipe comprises a shell and an inner pipe; the shell has a hollow cubic structure; the upper surface of the shell is provided with a cylindrical through hole I, and the lower surface is provided with a cylindrical through hole II; the inner diameters of the cylindrical through hole I and the cylindrical through hole II are the same; the centers of the cylindrical through hole I and the cylindrical through hole II are on the same central axis; the inner pipe is arranged in the shell and located directly below the spinneret; the upper end of the inner pipe is connected with the cylindrical through hole I, and the lower end is connected with the cylindrical through hole II, so that the inner pipe and the shell form a jacket structure; the jacket is used for introducing 95℃ biphenyl-biphenyl ether to heat the inner pipe;

[0138] The distance between the upper end of the inner pipe and the spinneret is 50 cm, and the length of the inner pipe is 100 cm;

[0139] The number of the inner pipe, the cylindrical through hole I and the cylindrical through hole II is the same as that of the spinneret, and each corresponds to one spinneret;

[0140] The process parameters are as follows:

[0141] The three rollers include a first hot roller, a second hot roller and a third hot roller; the temperature of the first hot roller is 80℃, the temperature of the second hot roller is 120℃, and the temperature of the third hot roller is 150℃;

[0142] The oil agent used for oiling is composed of 2 wt% epoxy chain extender and 98 wt% D972 oil agent of DAKO brand;

[0143] The side-blowing temperature is 25℃, the side-blowing speed is 0.3 m / s, the side-blowing humidity is 75%, the drafting multiple is 3, and the winding hot roller speed is 3800 m / min.

[0144] The final bicomponent fiber had a filament fineness of 3.5 dtex, a breaking strength of 3.5 cN / dtex, an elongation at break of 27.45%, a number of breakages of 1.6 times / (48 positions·24 hours), and a lint rate of 0.12%.

Claims

1. A process for the production of bicomponent fibers, characterized in that, The polyester melt and the polyamide melt are extruded from the spinneret in parallel, and then the as-spun fibers are obtained by side-blowing cooling, and then the as-spun fibers are sequentially heated by a heat pipe, oiled, pre-networked, three-roll drawn, heat set and wound to obtain the bicomponent fibers. The heat pipe is used to heat the as-spun fibers, and the temperature of the heat pipe is 90-100 DEG C. The three rolls include a first hot roll, a second hot roll and a third hot roll; the temperature of the first hot roll is 70-90 DEG C, the temperature of the second hot roll is 110-130 DEG C, and the temperature of the third hot roll is 140-160 DEG C.

2. A process for producing bicomponent fibers according to claim 1, characterized in that, The heat pipe includes a shell and an inner pipe; the shell is a hollow cubic structure; the upper surface of the shell is provided with a cylindrical through hole I, and the lower surface of the shell is provided with a cylindrical through hole II; the inner diameters of the cylindrical through hole I and the cylindrical through hole II are the same; the centers of the cylindrical through hole I and the cylindrical through hole II are on the same central axis; the inner pipe is arranged in the shell, and the inner pipe is located directly below the spinneret; the upper end of the inner pipe is connected with the cylindrical through hole I, and the lower end of the inner pipe is connected with the cylindrical through hole II, so that the inner pipe and the shell form a jacket structure; the jacket is used to introduce 90-100 DEG C biphenyl-biphenyl ether to heat the inner pipe.

3. A process for the production of bicomponent fibers according to claim 2, characterized in that, The distance between the upper end of the inner pipe and the spinneret is 50 cm, and the length of the inner pipe is 100 cm.

4. A process for the production of bicomponent fibers according to claim 3, characterized in that, The number of the inner pipe, the cylindrical through hole I and the cylindrical through hole II is the same as that of the spinneret, and each of them corresponds to one spinneret.

5. The method of making a bicomponent fiber according to claim 1, wherein, The mass ratio of the polyester melt to the polyamide melt is 40-60:60-40.

6. The method of making a bicomponent fiber according to claim 1, wherein, The raw material of the polyamide melt is composed of polyamide chips, nano-mica masterbatch, antioxidant and dispersant; The addition amount of the antioxidant is 0.1-1 wt% of the polyamide melt, the addition amount of the dispersant is 0.1-1 wt% of the polyamide melt, and the addition amount of the nano-mica masterbatch is 4-6 wt% of the polyamide melt.

7. A process for the production of bicomponent fibers according to claim 6, characterized in that, The antioxidant is one or more of hindered phenolic antioxidant, amine antioxidant and phosphite antioxidant; the dispersant is PE wax or ethylene oxide-propylene oxide block copolymer ether oligomer; the number average molecular weight of the ethylene oxide-propylene oxide block copolymer ether oligomer is 200-10000.

8. The method of making a bicomponent fiber according to claim 1, wherein, The corresponding raw material of the polyester melt is polyester chips, and the intrinsic viscosity of the polyester chips is 0.6-0.65 dL / g; the intrinsic viscosity of the polyamide chips is 3.0-3.4 dL / g.

9. The method of making a bicomponent fiber according to claim 1, wherein, The oil agent used for oiling contains polyamide chain extender, and the addition amount of the polyamide chain extender is 1-3% of the total mass of the oil agent.

10. The method of making a bicomponent fiber according to claim 1, wherein, The process parameters further include that the side-blowing temperature is 20-30 DEG C, the side-blowing speed is 0.30-0.60 m / s, the side-blowing humidity is 75±5%, the draw ratio is 2.5-3.0, and the winding speed is 3800-4500 m / min.

11. Bicomponent fibers prepared according to the process of any one of claims 1 to 10, characterized in that, The single filament fineness of the bicomponent fibers is 2.6-3.5 dtex, the breaking strength is ≥3.23 cN / dtex, the breaking elongation is 27.45-38.31%, the number of breakage is ≤2.3 times / (48 positions·24 hours), and the hairiness rate is 0.30% or less.

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