PA-PLA bi-component composite fiber and preparation method thereof

Abstract

The invention provides a preparation method of a PA-PLA (polyamide-polylactic acid) bi-component composite fiber, which comprises the following steps: a) mixing inorganic nano powder, PA slices and a dispersing agent, and carrying out melt extrusion granulation to obtain antibacterial master batch; b) mixing the antibacterial master batch obtained in the step a) with PA slices to obtain modified PA slices; and c) mixing the modified PA slice obtained in the step b) with the PLA slice, and carrying out melt spinning to obtain the PA-PLA bi-component composite fiber. Compared with the prior art, the preparation method provided by the invention has the advantages that the PA slices and the PLA slices are adopted as main raw materials, the overall better interaction is realized through a melt spinning process, the PA and PLA bi-component composite fiber is prepared, the anti-mite and antibacterial effects of the polylactic acid fiber are exerted, the strength and durability of the fiber are ensured, and the preparation method is simple and convenient. Moreover, the problem of polylactic acid dyeing is solved to a certain extent, and polylactic acid is used as a natural bacteriostatic auxiliary material.

Description

Technical Field

[0001] The present invention relates to the technical field of composite fibers, and more specifically, to a PA-PLA two-component composite fiber and a preparation method thereof. Background Art

[0002] Core-sheath composite fibers are made of polymers with different properties or structures, with one component surrounding another component or covering each other layer by layer and compounded along the fiber axis. Core-sheath composite fibers can be divided into several types, such as concentric circular type, eccentric circular type, and special-shaped cross-section type. This type of fiber can produce different shapes and effects by utilizing the different properties of each component.

[0003] Polyamide fiber (PA) refers to a type of synthetic fiber with amide groups on the main chain of the molecule, commonly known as nylon, and its trade name in my country is nylon; it has excellent strength, wear resistance, elastic recovery rate, and hygroscopicity. Polylactic acid (PLA) is a new type of environmentally friendly polyester material, a high molecular polymer formed by the polymerization of single lactic acid molecules or the ring-opening polymerization of lactide; since the raw material of polylactic acid, lactic acid, is an endogenous substance in the human body, its fibers and products have good biocompatibility and are non-allergenic; the slow degradation process of polylactic acid makes the fiber surface weakly acidic like lactic acid, so polylactic acid fiber fabrics not only have excellent natural antibacterial properties, can effectively inhibit the breeding of mites, and have anti-mildew and anti-odor effects; polylactic acid fiber fabric products are highly safe and are natural and good bio-based fibers.

[0004] However, due to the degradability of polylactic acid, affected by temperature, humidity, pH, sunlight, etc., various environments and working conditions will accelerate the decomposition of polylactic acid fibers during raw material storage, spinning, fabric weaving, dyeing and finishing, transportation, and fabric use, thereby affecting the comprehensive mechanical properties of polylactic acid fibers. In the current industry, polylactic acid fibers for textiles are all single components. In order to ensure the performance and texture of fabrics containing polylactic acid fibers, the method used in the prior art is to blend them with cotton, traditional petroleum-based fibers, regenerated cellulose fibers, etc., thereby compensating for and covering up the shortcomings of polylactic acid fibers to a certain extent. Another method is to produce bicomponent fibers of polylactic acid and other raw materials that can use melt spinning processes (such as petroleum-based plastics), such as the Chinese patent with application number 202011264724.9, which discloses a sc-PLA / PTT biomass composite fiber and its preparation method and application. In addition, there is another method: using polylactic acid staple fibers and other types of staple fibers to make blended yarns.

[0005] At present, the dyeing of polylactic acid fiber fabrics is mainly light-colored. Due to the temperature-sensitive nature of polylactic acid fibers, they cannot be dyed at high temperatures like polyester, and can only be dyed at 110°C. The setting temperature exceeding 120°C will cause the polylactic acid fibers to crystallize and harden. Polylactic acid fibers are particularly sensitive to temperature and alkali agents, and strong alkalis will degrade polylactic acid. Polylactic acid fiber is a type of polymer and must be dyed with dispersed materials. However, due to the characteristics of most dispersed materials, high temperatures are required to push the dye into the fiber, so polylactic acid fibers have always had problems such as low dye uptake and poor color fastness when dyeing. Another dark coloring method is to use masterbatches to add polylactic acid raw materials to produce colored yarns during the melt spinning process. In the molten state, the viscosity of polylactic acid is twice that of PET, which is also a polyester. Masterbatches are not easy to diffuse in the melt, and it is necessary to develop a special masterbatch formula for polylactic acid. In addition, during the use of fabrics containing polylactic acid, especially during washing, the dye in the fiber will be released into the water as the polylactic acid molecules degrade, which also leads to poor color fastness of polylactic acid fabrics. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a PA-PLA two-component composite fiber and a preparation method thereof, and to produce a polylactic acid and nylon two-component composite fiber by a melt spinning process, while exerting the anti-mite and antibacterial effects of polylactic acid fiber, ensuring the fiber strength and durability, and to a certain extent solving the polylactic acid dyeing problem, while using polylactic acid as a natural antibacterial auxiliary material.

[0007] The present invention provides a method for preparing a PA-PLA two-component composite fiber, comprising the following steps:

[0008] a) mixing inorganic nanopowder, PA slices and a dispersant, and performing melt extrusion granulation to obtain an antibacterial masterbatch;

[0009] b) mixing the antibacterial masterbatch obtained in step a) with PA slices to obtain modified PA slices;

[0010] c) mixing the modified PA slices obtained in step b) with the PLA slices, and performing melt spinning to obtain PA-PLA bicomponent composite fibers.

[0011] Preferably, the mass ratio of the inorganic nanopowder, PA slices and dispersant in step a) is 1:(18-20):(0.005-0.015).

[0012] Preferably, the melt temperatures of the melt extrusion granulation in step a) are: 250° C. in the first zone of the die, 245° C. in the first zone of the barrel, 248° C. in the second zone of the barrel, and 248° C. in the third zone of the barrel.

[0013] Preferably, the antibacterial masterbatch in step b) is placed in a vacuum oven at 100° C. to 105° C. and dried for 6 h to 10 h before mixing.

[0014] Preferably, the mass ratio of the antibacterial masterbatch to the PA slice in step b) is 1:(18-20).

[0015] Preferably, the volume ratio of the modified PA slice to the PLA slice in step c) is 7:(1-5).

[0016] Preferably, the melt spinning process in step c) is specifically as follows:

[0017] The raw materials are pre-dried, dried, and melted in sequence, and then compounded through a spinneret assembly to obtain PA-PLA two-component composite fibers.

[0018] Preferably, the pre-drying temperature is 80°C to 90°C, and the time is 2h to 4h; the drying temperature is 100°C to 110°C, and the time is 7h to 9h.

[0019] Preferably, the melting temperature is:

[0020] The spinning temperature of PA was set at 260°C to 270°C, and the spinning temperature of PLA was set at 210°C to 220°C.

[0021] The present invention also provides a PA-PLA two-component composite fiber, which is prepared by the preparation method described in the above technical solution.

[0022] The present invention provides a preparation method of PA-PLA two-component composite fiber, comprising the following steps: a) mixing inorganic nanopowder, PA slices and dispersant, and performing melt extrusion granulation to obtain antibacterial masterbatch; b) mixing the antibacterial masterbatch obtained in step a) with PA slices to obtain modified PA slices; c) mixing the modified PA slices obtained in step b) with PLA slices, and performing melt spinning to obtain PA-PLA two-component composite fiber. Compared with the prior art, the preparation method provided by the present invention uses PA slices and PLA slices as main raw materials, and achieves overall good interaction through a melt spinning process, and prepares PA and PLA two-component composite fibers, which ensures fiber strength and durability while exerting the anti-mite and antibacterial effect of polylactic acid fiber, and solves the problem of polylactic acid dyeing to a certain extent, and uses polylactic acid as a natural antibacterial auxiliary material. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The present invention provides a method for preparing a PA-PLA two-component composite fiber, comprising the following steps:

[0025] a) mixing inorganic nanopowder, PA slices and a dispersant, and performing melt extrusion granulation to obtain an antibacterial masterbatch;

[0026] b) mixing the antibacterial masterbatch obtained in step a) with PA slices to obtain modified PA slices;

[0027] c) mixing the modified PA slices obtained in step b) with the PLA slices, and performing melt spinning to obtain PA-PLA bicomponent composite fibers.

[0028] The present invention aims to solve the following technical problems of PLA: (1) poor dyeing performance; (2) mechanical properties such as elasticity and strength are quite different from those of traditional petroleum-based plastic fibers; (3) PLA is a bio-based material with biodegradability. Since the PLA slices made by each raw material supplier have different processes, upstream raw materials, continuous production conditions, equipment, and different raw material modification formulas and fiber production processes, the mechanical properties of PLA fibers and other indicators will change at different rates over time; that is, to solve the problem of exhaustion stability in the application of PLA fiber materials; (4) to increase natural antibacterial and antimicrobial properties for petroleum-based plastics; (5) to reduce the moisture regain of petroleum-based fibers (nylon / PA) and improve the comfort of sports fabrics.

[0029] On this basis, the present invention provides a method for preparing a PA-PLA two-component composite fiber. The present invention first mixes an inorganic nano powder, a PA slice and a dispersant, and performs melt extrusion granulation to obtain an antibacterial masterbatch. The present invention has no special restrictions on the sources of the inorganic nano powder, the PA slice and the dispersant, and commercially available products known to those skilled in the art can be used.

[0030] In the present invention, the inorganic nanopowder is preferably one or more of nano zinc oxide, nano magnesium oxide and nano silicon oxide, more preferably nano zinc oxide; the dispersant is preferably one or more of zinc stearate, polyethylene wax and stearic acid, more preferably zinc stearate.

[0031] In the present invention, the mass ratio of the inorganic nanopowder, PA slices and dispersant is preferably 1:(18-20):(0.005-0.015), and more preferably 1:19:0.01.

[0032] In the present invention, the melt extrusion granulation device preferably adopts a granulator well known to those skilled in the art, and the melt extrusion granulation is carried out by screw melt extrusion; the melting temperature of the melt extrusion granulation is preferably: 250°C in the first zone of the head, 245°C in the first zone of the barrel, 248°C in the second zone of the barrel, and 248°C in the third zone of the barrel.

[0033] After obtaining the antibacterial masterbatch, the present invention mixes the obtained antibacterial masterbatch with PA slices to obtain modified PA slices.

[0034] In the present invention, the antibacterial masterbatch is preferably placed in a vacuum oven at 100° C. to 105° C. for drying for 6 h to 10 h before mixing.

[0035] The present invention preferably adopts an online masterbatch adding device to add the antibacterial masterbatch and PA6 slices into a PA6 hopper as modified PA6 slices; the mass ratio of the antibacterial masterbatch to the PA slices is preferably 1: (18-20).

[0036] After obtaining the modified PA slices, the present invention mixes the obtained modified PA slices with PLA slices and performs melt spinning to obtain PA-PLA bicomponent composite fibers. The present invention has no particular limitation on the source of the PLA slices, and commercially available products known to those skilled in the art can be used.

[0037] In the present invention, the raw material PA slices and PLA slices are both spinning-grade slices, and the present invention has no special limitation on this.

[0038] In the present invention, the volume ratio of the modified PA slice to the PLA slice is preferably 7:(1-5), more preferably 7:3.

[0039] In the present invention, the melt spinning process is preferably as follows:

[0040] The raw materials are pre-dried, dried, and melted in sequence, and then compounded through a spinneret assembly to obtain PA-PLA two-component composite fibers.

[0041] The present invention adopts the above-mentioned melt spinning process, which specifically includes: pre-drying of raw materials, drying of raw materials, raw materials entering a hopper, two raw materials entering separate screw extruders respectively, melting in the screw, polymer melt being extruded from the capillary holes of the spinneret to become melt streams, cooling the melt streams, and obtaining pre-oriented yarns (POY).

[0042] In the present invention, the pre-drying temperature is preferably 80° C. to 90° C., and the time is preferably 2 h to 4 h; the drying temperature is preferably 100° C. to 110° C., and the time is preferably 7 h to 9 h.

[0043] In the present invention, after the drying, before the raw material enters the hopper, it is preferred that the following steps are further included:

[0044] If it is an eccentric skin-core structure, if there is a special color requirement, the corresponding masterbatch or additives can be added to the PLA slices to achieve the color consistency requirements during the back-end fabric dyeing and finishing.

[0045] In the present invention, the melting temperature is preferably:

[0046] The spinning temperature of PA was set at 260°C to 270°C, and the spinning temperature of PLA was set at 210°C to 220°C.

[0047] In the present invention, the spinneret assembly is preferably a two-component spinneret assembly of different forms, so that the production of composite fibers with different structures can be achieved, such as eccentric skin-core, island-shaped, etc.; in a preferred embodiment of the present invention, the molten polymer melt enters the spinneret assembly from the screw, the assembly temperature is set to 240°C to 260°C, and is extruded through the capillary holes of the spinneret to become a melt stream; thereafter, the present invention cools the melt stream to obtain a pre-oriented yarn, wherein PA (polyamide) is used as the skin layer and PLA (polylactic acid) is used as the core layer, and the PA fiber is coated on the PLA fiber, and cooled and solidified in an anemometer at a temperature of 18 to 22°C and a humidity of 58 to 60% to obtain a PA-PLA two-component composite fiber.

[0048] In the present invention, the spinning speed is preferably 3000 m / min to 4000 m / min.

[0049] The present invention also provides a PA-PLA two-component composite fiber, which is prepared by the preparation method described in the above technical solution.

[0050] In the present invention, the composition and morphology of the PA-PLA bicomponent composite fiber are as follows:

[0051] The product provided by the present invention is a two-component fiber, mainly composed of PA and supplemented by PLA; in melt spinning, the proportion of PA (polyamide) is preferably not more than 75%, and the proportion of PLA (polylactic acid) is preferably not less than 25%; among which, polyamide fiber varieties include but are not limited to polyamide 6, polyamide 66, etc.

[0052] In addition to being able to be made into the above-mentioned skin-core structure, the present invention can also be made into an island structure, a fibril dispersion structure, etc., which is specifically adjusted through a spinneret assembly; the skin-core has polyamide (PA) as the skin and polylactic acid (PLA) as the core, and can be made into several forms such as concentric circles, eccentric circles, and special-shaped cross-sections; the island structure has PA as the matrix (sea), and PLA is distributed in the matrix fiber in the form of fine fibers (islands); its "island" and "sea" components are continuous, dense, and evenly distributed in the axial direction of the fiber; the fibril dispersion structure is similar to the island structure, but on the cross-section of the fiber, the size and distribution position of the fibrils are random, and the fibrils are discontinuously distributed along the axial direction of the fiber.

[0053] The present invention adopts the preparation method described in the above technical scheme, wherein the polylactic acid fiber is used as the core wire and the modified nylon fiber is used as the coating layer, which is coated on the outside of the polylactic acid fiber. The composite fiber obtained in this way not only has antibacterial and antimicrobial properties, but also has more lasting antibacterial and antimicrobial properties of the composite fiber and durability of the polylactic acid fiber due to the protective effect of the nylon fiber.

[0054] The PA-PLA bicomponent composite fiber prepared by the preparation method provided by the present invention can be used as a fiber for textile fabrics and can be post-processed as DTY (drawn textured yarn) and FDY (high-speed spinning and drawing one-step process, fully drawn yarn); wherein:

[0055] FDY process: POY (pre-oriented yarn) enters the first hot roller at a speed slightly higher than the POY spinning speed of 3000m / min-4500m / min, and the speed of the second hot roller is 3600m / min-5600m / min; for POY with a certain degree of orientation, the stretching multiple of the present invention is 1.2-1.3; at the same time, in order to increase the yarn, cohesion, corresponding to PA6\PA66, etc., use correspondingly adapted oil, and set 50-100 intertwining nodes for each yarn speed.

[0056] DTY process: DTY is to make POY first, and then POY is stretched through a texturing machine. The main process flow is first hot box → cooling plate → false twister → network nozzle → lower hot box → winding; core parameters: texturing speed 600-800 meters, draft ratio 1.1-1.2, deformation temperature 170-175℃, false twister uses 1 / 5 / 1 ceramic false twist disk, setting temperature 160-165℃, network pressure 1.5kg.

[0057] The present invention provides a PA-PLA two-component composite fiber and a preparation method thereof, which has the following beneficial effects:

[0058] (1) The present invention solves the problem of dyeing fabrics containing polylactic acid; the present invention is a polyamide and polylactic acid two-component composite fiber, the fiber cross-section morphology is a sheath-core composite fiber, with polyamide as the sheath and polylactic acid as the core, and has the advantages of both nylon and polylactic acid; because the advantage of nylon being easy to dye is fully utilized, it has excellent dyeability, can use normal pressure dyeing equipment, and is easy to operate; the equipment uses acid dyes with a relatively complete color spectrum, bright colors, good color fastness, and disperse dyes with good levelness.

[0059] (2) The present invention maintains the advantages of nylon, such as good resilience and good wear resistance, and overcomes the weaknesses of polylactic acid, such as difficulty in dyeing, low moisture absorption, and easy aging.

[0060] (3) The present invention does not use various antibacterial and antibacterial additives, but relies on the natural antibacterial properties of polylactic acid to make the manufactured fabric meet the requirements of GB18401-2010 (Class A) and GB31701-2015 (Class B).

[0061] (4) Polyamide-polylactic acid eccentric composite filament, due to the different thermal shrinkage of the two polymers, the fiber presents three-dimensional spatial curling, and its curling performance is between nylon high-elastic yarn and polyester low-elastic yarn. It can be directly used in the knitting industry without adding elasticity.

[0062] (5) The current market price of polylactic acid filaments is RMB 42,000 / ton. The present invention solves the problem of high prices of polylactic acid filament fabric products. Based on the current raw material prices, the comprehensive cost of the product is RMB 23,000 / ton. The present invention expands the market application scenarios of polylactic acid.

[0063] The present invention provides a preparation method of PA-PLA two-component composite fiber, comprising the following steps: a) mixing inorganic nano powder, PA slices and dispersant, and performing melt extrusion granulation to obtain antibacterial masterbatch; b) mixing the antibacterial masterbatch obtained in step a) with PA slices to obtain modified PA slices; c) mixing the modified PA slices obtained in step b) with PLA slices, and performing melt spinning to obtain PA-PLA two-component composite fiber. Compared with the prior art, the preparation method provided by the present invention uses PA slices and PLA slices as main raw materials, and achieves overall good interaction through a melt spinning process, thereby preparing PA and PLA two-component composite fibers. While maintaining the original dyeing, elasticity, moisture absorption and other properties of PA, PLA with natural antibacterial ability is added to prepare composite fibers, thereby reducing the use of petroleum-based plastics, effectively fulfilling the "dual carbon" responsibility, and providing users with natural anti-mite and antibacterial effects and relatively low-priced products without adding additives.

[0064] In order to further illustrate the present invention, the following examples are used to explain it in detail. The raw materials used in the following examples of the present invention are all commercially available; among them, the slice manufacturer: PA6 Xinhui Meida M2500i, M2800, polylactic acid is Fengyuan FY601, FY602, FY802.

[0065] Example

[0066] (1) Nano ZnO, PA6 slice M2800 and dispersant zinc stearate were weighed, mixed in a mass ratio of 5:95:0.05, and fed into a granulator, and melt-extruded and granulated by a screw to prepare an antibacterial masterbatch;

[0067] The melting temperatures are: 250°C in the first zone of the die, 245°C in the first zone of the barrel, 248°C in the second zone of the barrel, and 248°C in the third zone of the barrel. The prepared antibacterial masterbatch is placed in a vacuum oven at 102°C and dried for 8 hours and then stored for later use.

[0068] (2) using an online masterbatch adding device, adding the antibacterial masterbatch obtained in step (1) and PA6 slices into a PA6 hopper, with the mass ratio of the antibacterial masterbatch to PA6 being 5:95, as modified PA6 slices; then the modified PA6 slices and PLA slices FY601 are put into a melt spinning process at a volume ratio of 70:30 to obtain a modified PA-PLA bicomponent composite fiber with a skin-core structure, wherein the skin layer is PA and the core layer is PLA;

[0069] The melt spinning process is as follows:

[0070] ① Pre-drying of raw materials: The modified PA6 slices are dried at 85℃ for 3 hours, and the PLA slices are dried at 85℃ for 3 hours;

[0071] ②Formal drying of raw materials: Modified PA6 slices are dried at 105℃ for 8 hours, and PLA slices are also dried at 105℃ for 8 hours;

[0072] ③ After the raw materials are dried and before entering the hopper, if it is an eccentric skin-core structure, if there is a special color requirement, the corresponding masterbatch or additives can be added to the PLA slices to achieve the color consistency requirements during the back-end fabric dyeing and finishing;

[0073] ④ Melting: The two raw materials enter separate screw extruders from the hoppers. The spinning temperature of PA is set at 260℃~270℃, and the spinning temperature of PLA is set at 210℃~220℃, and they are melted in the screw.

[0074] ⑤ Preparation of composite fibers: The polymer melt enters the 250°C spinneret capillary holes from the screw and is extruded into a melt stream, which is cooled to obtain a pre-oriented yarn (POY); wherein PA (polyamide) is used as the sheath layer and PLA (polylactic acid) is used as the core layer, and the PA fiber is coated on the PLA fiber, and cooled and solidified in an anemometer at a temperature of 18 to 22°C and a humidity of 58 to 60%; the spinning speed is 3500 m / min.

[0075] After testing, the mechanical properties of the PA-PLA two-component composite fiber provided by the embodiment of the present invention are as follows: elongation at break is 35%, and breaking strength is 4.5 cN / dtex; at the same time, the wear resistance of nylon is 10 times that of cotton. The PA-PLA two-component composite fiber with PA as the cortex of the present invention has excellent wear resistance.

[0076] The PA-PLA bicomponent composite fiber prepared by the preparation method provided by the present invention can be used as a fiber for textile fabrics and can be post-processed as DTY (drawn textured yarn) and FDY (high-speed spinning and drawing one-step process, fully drawn yarn); wherein:

[0077] FDY process: POY (pre-oriented yarn) enters the first hot roller at a speed slightly higher than the POY spinning speed of 4000m / min, and the speed of the second hot roller is 4600m / min; for POY with a certain degree of orientation, the stretching multiple of the present invention is 1.2-1.3; at the same time, in order to increase the yarn, cohesion, corresponding to PA6\PA66, etc., use correspondingly adapted oil, and set 80 intertwining nodes for each yarn speed.

[0078] DTY process: DTY is to make POY first, and then POY is stretched through a texturing machine. The main process flow is first hot box → cooling plate → false twister → network nozzle → lower hot box → winding; core parameters: texturing speed 700 meters, draft ratio 1.1~1.2, deformation temperature 170~175℃, false twister uses 1 / 5 / 1 type ceramic false twist disk, setting temperature 160~165℃, network pressure 1.5kg.

[0079] Performance Test:

[0080] The PA-PLA bicomponent composite fiber provided in the embodiment is used for textile fabrics for clothing, the yarn composition is the PA-PLA volume fraction of 70-30, and is woven into weft knitted fabrics. The antibacterial properties of the fabrics are shown in Table 1 below, and the physical properties of the fabrics are shown in Table 2 below.

[0081] Table 1

[0082] Bacteria Antibacterial rate / % Candida albicans 95 Escherichia coli 98 Staphylococcus aureus 99

[0083] Table 2

[0084] Breaking strength Warp GBT3923.1 ≥200 750 N Weft GBT3923.1 ≥200 480 N Seam performance J3004 ≤0.6 0.15 Cm

[0085] The present invention tests the antibacterial and anti-mite properties of different fabrics:

[0086] Polylactic acid decomposes slowly during use, making the fiber surface a weakly acidic environment, which has antibacterial, antifungal and mildew-proof effects; even if the PLA content in the fabric is low (about 10%), it also has a good broad-spectrum antibacterial effect, and its mechanism is that PLA creates a weakly acidic environment that is not conducive to bacterial growth; in addition, the more PLA components in the fabric, the better its anti-mite and antibacterial effect; the present invention can obtain a better anti-mite effect by adjusting the ratio of PA to PLA and the distribution morphology of PLA in the fiber, as shown in Tables 3 and 4 below, wherein Table 3 shows the broad-spectrum antibacterial effect (the fabric is 100% PLA), and Table 4 shows the mite repellency rate (the relationship between the fabric PLA ratio and the repellency rate).

[0087] Table 3

[0088]

[0089]

[0090] Table 4

[0091]

[0092]

[0093] Dyeing performance:

[0094] (1) Masterbatch dyeing example: Pleasant Blue.

[0095] Add the masterbatch model to the hopper: BT-1842A, manufacturer: Changzhou Futong Masterbatch Factory, dosage: 1-8%;

[0096] Soap fastness grades: CA4 / 5, CO4 / 5, PA4 / 5.

[0097] (2) Back-end dyeing and color fastness test examples:

[0098] Process flow: disperse dyeing → washing → reduction washing → washing → drying → fastness test.

[0099] Pretreatment: soda ash 1g / L, hydrogen peroxide 1-2g / L.

[0100] Dyeing: Dyeing temperature ≤ 110℃, 45min, bath ratio 1:20, pH=4.5, try not to add leveling agent, use disperse dye PLA-XFN cyan black for black, and according to the color depth, disperse dye 1~7%; adjust the acid with glacial acetic acid, and control the pH value at 4.5~5.5.

[0101] Color fixing: reduction washing 4g / L hydrosulfite + 1g / L soda ash, 70℃10min, bath ratio 1:20, color fixing agent 25g / L polyester color fixing agent.

[0102] Soap washing: Soap washing temperature ≤ 70℃, use neutral low-foaming low-temperature soaping agent.

[0103] Color fastness test: Soap washing GB / T3921 40℃, test results see Table 5 below.

[0104] Table 5

[0105] Dyeing formula Color change grading after reduction washing Disperse black 1.0% 3.5 Disperse black 3.0% 3.5 Disperse black 5.0% 3.5 Disperse black 7.0% 3.5

[0106] Soap fastness grades: CA4 / 5, CO4 / 5, PA4 / 5, PET4 / 5, wool 4 / 5.

[0107] It can be seen that the PA-PLA two-component composite fiber provided by the embodiment of the present invention solves the problems of color fastness, dyeing performance and dyeing examples.

[0108] In summary, the present invention provides a PA-PLA two-component composite fiber and a preparation method thereof. PA, as the cortex of the composite fiber, characterizes good properties including dyeing, rebound, fatigue resistance, wear resistance, etc., which are easy to dye and not easy to fade; although the dyeability of polyamide fiber is not as good as that of natural fiber and artificial fiber, it is easier to dye among synthetic fibers, and generally acid dyes, disperse dyes and other dyes can be used; other mechanical properties such as strength are basically the same as those of nylon fiber. At the same time, the present invention develops the production process technology and process of PA / PLA composite fiber POY to FDY and DTY. In addition, in addition to the two-component skin-core structure, the present invention can also be made into an island structure, a fibril dispersion structure, etc. according to actual conditions to meet the effects of 3D curled yarn, improving modulus, feel, moisture absorption effect, deformation ability, etc. In order to meet the international ESG related certification, the PLA content of the present invention cannot be less than 25%, and when there is a special need, the maximum is not higher than 80%; maintain its antibacterial and antibacterial stability and pass the US USDA certification; in order to have a price advantage over pure PLA fiber, the PA content should not be less than 50%. Finally, the core parameter of configuring PA and PLA to make composite fibers in the present invention is the dyeing temperature. The dyeing temperature of PA is 90-100°C, and the dyeing temperature of PLA is 100-110°C, which are similar in range. Compared with pure PLA yarn, the present invention is more cost-effective and can more easily promote the application of PLA materials on a large scale.

[0109] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a PA-PLA bicomponent composite fiber, characterized in that: The following steps are involved: a) mixing inorganic nanopowder, PA slices and a dispersant, and performing melt extrusion granulation to obtain an antibacterial masterbatch; b) mixing the antibacterial masterbatch obtained in step a) with PA slices to obtain modified PA slices; c) mixing the modified PA slices obtained in step b) with the PLA slices, and performing melt spinning to obtain PA-PLA bicomponent composite fibers.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the inorganic nanopowder, PA slices and dispersant in step a) is 1:(18-20):(0.005-0.015).

3. The preparation method according to claim 1, characterized in that: The melting temperatures of the melt extrusion granulation in step a) are: 250° C. in the first zone of the die, 245° C. in the first zone of the barrel, 248° C. in the second zone of the barrel, and 248° C. in the third zone of the barrel.

4. The preparation method according to claim 1, characterized in that: The antibacterial masterbatch in step b) is placed in a vacuum oven at 100° C. to 105° C. and dried for 6 h to 10 h before mixing.

5. The preparation method according to claim 1, characterized in that: The mass ratio of the antibacterial masterbatch to the PA slice in step b) is 1:(18-20).

6. The preparation method according to claim 1, characterized in that: The volume ratio of the modified PA slice to the PLA slice in step c) is 7:(1-5).

7. The preparation method according to claim 1, characterized in that: The melt spinning process in step c) is specifically as follows: The raw materials are pre-dried, dried, and melted in sequence, and then compounded through a spinneret assembly to obtain PA-PLA two-component composite fibers.

8. The preparation method according to claim 7, characterized in that: The pre-drying temperature is 80° C. to 90° C., and the time is 2 h to 4 h; the drying temperature is 100° C. to 110° C., and the time is 7 h to 9 h.

9. The preparation method according to claim 7, characterized in that: The melting temperature is: The spinning temperature of PA was set at 260°C to 270°C, and the spinning temperature of PLA was set at 210°C to 220°C.

10. A PA-PLA bicomponent composite fiber, characterized in that: The preparation method is described in any one of claims 1 to 9.

Images