Artificial down fiber for filling and preparation method and application thereof

Abstract

The invention relates to the technical field of textile, and provides an artificial down fiber for filling and a preparation method and application thereof.The artificial down fiber is prepared by drafting and cutting a nascent filament or a pre-oriented filament prepared through a melt spinning technology, and the artificial down fiber comprises a bi-component parallel composite fiber internally containing a cavity structure; the whole fiber is in a natural curled form in the longitudinal direction, both the component A and the component B of the bi-component parallel composite fiber contain PHA, and the semi-crystallization time t1 / 2 of the component A and the component B is different. The content of the PHA material in the prepared artificial down fiber is high, the crystallization characteristic of PHA is fully considered, other auxiliaries are cooperated, more prominent effects such as antibiosis, mite prevention, hydrophobicity, static electricity resistance, low modulus, degradability and environmental protection are achieved, particularly, a cavity structure is contained, so that the weight is smaller, the filling power is higher, the heat retention property is good, the artificial down fiber is a good substitute of down, and the artificial down fiber is worthy of popularization and application. The fiber can be mixed with other down filling fibers for application.

Description

Technical Field

[0001] The present invention relates to the technical field, and in particular to an artificial down fiber for filling, a preparation method thereof, and an application thereof. Background Art

[0002] With the popularization of concepts such as environmental protection and low carbon, the development prospects of bio-based fibers or degradable fibers are very broad. However, for a degradable material such as PHA that is environmentally friendly throughout its life cycle, its applications in textiles, non-wovens, etc. are still in the exploratory stage, and its advantages such as rapid degradation, biocompatibility, antibacterial property, and easy dyeing have not been fully utilized, especially in the application field of medium and high-end textiles. There is no effective method in the prior art to prepare PHA artificial down fibers, and PHA-based artificial down fibers that can take into account mechanical properties and environmental protection and other characteristics are also urgently needed to be invented and improved.

[0003] In the process of researching down-filled products, it is found that existing artificial down fiber products mainly use traditional chemical fiber polyester materials. For example, the bicomponent side-by-side composite fiber with a hollow "O" - shaped structure recorded in patent CN106757427B shows good wrinkle resistance, high elastic recovery force, good fluffiness, etc. when used in imitation down products. Fibers with permanent crimps, cavities and sealed ends can be regarded as the "ceiling" of imitation down fibers. The present invention attempts to apply PHA materials to the textile field to make a similar structure, but it is found that it is not easy to successfully prepare. Summary of the Invention

[0004] The present invention provides an artificial down fiber for filling by improving the raw material composition of PHA materials and combining with fiber structure design. The artificial down fiber can give full play to the characteristics of PHA, such as environmental protection and excellent comprehensive performance. Moreover, when its cross-section is designed to contain a cavity structure, the artificial down fiber is lighter in weight, and its warmth retention performance can reach that of 95% duck down / 85% goose down.

[0005] Furthermore, the artificial down fiber and additives can cooperate to achieve more abundant functional characteristics, such as antibacterial, anti - mite, hydrophobic, antistatic, low modulus, etc.

[0006] Specifically, the present invention provides an artificial down fiber, which is obtained by cutting a nascent fiber or a pre - oriented fiber prepared by a melt - spinning process after drawing. The artificial down fiber is a bicomponent side - by - side composite fiber with a cavity structure inside, and the fiber is in a natural crimped shape longitudinally as a whole;

[0007] Both component A and component B of the bicomponent side - by - side composite fiber contain PHA; the semi - crystallization times of component A and component B of the bicomponent side - by - side composite fiber are different;

[0008] The PHA includes PHA copolymers and / or PHA homopolymers;

[0009] The PHA copolymer has two or more comonomers, and the monomer units include the structure of formula (I):

[0010]

[0011] In formula (I), R 1 is H or an alkyl or alkenyl group of C 1-19 , and n is an integer from 0 to 19; each monomer unit is different;

[0012] The PHA homopolymer has one repeating unit, and the repeating unit includes the structure of formula (II):

[0013]

[0014] In formula (II), R 2 is H or an alkyl or alkenyl group of C 1-19 , when R 2 is H, s is an integer from 0 to 3 or 5 to 19, and when R 2 is an alkyl or alkenyl group of C 1-19 , s is an integer from 0 to 19.

[0015] The overall profile of the cross-section of the artificial down fiber 2 in the present invention is not limited and can be: circle, ellipse, semi-circle, chord shape, sector, triangle, rectangle, rhombus, trapezoid, pentagon, three-leaf shape, hexagon, cross star shape, pentagram or other multi-angle star shapes, etc. The shape of the cavity structure 1 on the cross-section can also be circle, ellipse, semi-circle, chord shape, sector, triangle, rectangle, rhombus, trapezoid, pentagon, three-leaf shape, hexagon, cross star shape, pentagram or other multi-angle star shapes, etc. The specific structure is as shown in Figures 1 to 6 .

[0016] Preferably, when the cross-sectional shape of the fiber is triangle, three-leaf shape, multi-angle or multi-leaf, it helps to improve the comfort of the hand feeling, has better warmth retention, has a strong wool feeling, the fibers can be entangled with each other and stand up fluffy, and has a three-dimensional sense and a plump and thick feeling. The reason is that for angular or leaf-shaped profiled fibers, their friction coefficient is larger, the stiffness is also larger, and due to the inability to be arranged closely, the gaps between the fibers are larger, thus improving the fluffiness, warmth retention and air permeability.

[0017] Preferably, when the shape of the cavity structure on the cross-section is circle or ellipse, the spinning difficulty can be reduced, which helps to improve the bending resistance and wear resistance (the internal stress of the fiber with a cavity is smaller). At the same time, due to the increase in the hollowness, the space occupied by the fibers of the same mass is larger, and the static air (with a low thermal conductivity) trapped in them is more, thus further improving the fluffiness and warmth retention.

[0018] The artificial down fiber of the present invention can be obtained by a conventional melt-spinning method for bicomponent parallel composite fibers when both components A and B contain PHA and the half-crystallization times of components A and B are different. To achieve the objectives of the present invention, the present invention controls the degree of natural curl by rationally designing the raw material components. Experiments have found that the greater the difference in crystallization rate between the PHA contained in components A and B, the higher the curl naturally formed in the fiber after stretching.

[0019] According to the artificial down fiber provided by the present invention, the half-crystallization time t 1 / 2 The half crystallization time t of component B 1 / 2 Less than 10 seconds.

[0020] According to the artificial down fiber provided by the present invention, the cross section of the artificial down fiber contains the cavity structure with an area accounting for 20 to 75%.

[0021] In the experiment, it was found that the size of the cavity structure greatly affects the spinnability of the two-component parallel composite fiber and the degree to which the artificial down fiber takes into account the bulk, stiffness and warmth. When the cross-section of the fiber contains a cavity structure accounting for 20-75% of the area, under conventional cooling process conditions, the cooling effect of the fiber in the present invention is the best, and it is easier to form a three-dimensional curled shape. When the product is applied to the filling field with short fibers, it can have good bulk, stiffness and warmth. If the cavity ratio is too low, the stiffness is too large, and the bulk and warmth are not ideal; if the cavity ratio is too high, the fiber stiffness is not enough and it is difficult to maintain the bulk. After repeated compression and other mechanical actions during use, the static air in the cavity is easily lost, which reduces the bulk and even damages the fiber (the fiber is compressed and burst). After the static air is lost, the warmth will be greatly reduced.

[0022] Good spinnability in the present invention means that during continuous spinning, the fiber is unlikely to produce fuzz, floating fibers, or broken ends, and the continuous spinning can be carried out stably.

[0023] According to the artificial down fiber provided by the present invention, the cavity structures are distributed in component A and component B in equal proportions.

[0024] According to the artificial down fiber provided by the present invention, both component A and component B of the bicomponent parallel composite fiber contain PHA in an amount of more than 20% by mass.

[0025] Component A and component B of the two-component parallel composite fiber are mainly composed of PHA. The PHA materials in component A and component B are one or more types and are the same or different.

[0026] The crystallization rate of different PHA materials can be referred to as: PGA > P3HP > PLA > PHB > P34HB (molar content of 4HB is 5%) > P34HB (molar content of 4HB is 15%).

[0027] To make the semi-crystallization time of component A and component B meet the requirements of the present invention, specifically:

[0028] When component A is mainly PGA, it is preferred that component B is mainly one or more of P3HP, PLA, PHB, P34HB (molar content of 4HB is 5%) and P34HB (molar content of 4HB is 15%);

[0029] When component A is mainly P3HP, it is preferred that component B is mainly one or more of PLA, PHB, P34HB (molar content of 4HB is 5%) and P34HB (molar content of 4HB is 15%);

[0030] When component A is mainly PLA, it is preferred that component B is mainly one or more of PHB, P34HB (molar content of 4HB is 5%) and P34HB (molar content of 4HB is 15%);

[0031] When component A is mainly PHB, it is preferred that component B is mainly one or more of P34HB (molar content of 4HB is 5%) and P34HB (molar content of 4HB is 15%);

[0032] When component A is mainly P34HB (molar content of 4HB is 5%), it is preferred that component B is mainly P34HB (molar content of 4HB is 15%).

[0033] According to the artificial down fiber provided by the present invention, both component A and component B are mainly fast-crystallizing PHA or a combination thereof;

[0034] The fast-crystallizing PHA is PHB, P4HB, P3HP, P3HV, P5HV, P3HHx, P3HHp, P3HO, P3HN, P3HD or a PHA copolymer with a molar content of a repeating unit > 93%.

[0035] The PHA copolymer with a molar content of each repeating unit ≤ 93% is used as a slow-crystallizing PHA.

[0036] By adding the above fast-crystallizing PHA to both component A and component B, it helps to form better strength in the early stage of fiber forming, thereby improving the spinnability.

[0037] Generally, the higher the content of the fast-crystallizing PHA in component A, the higher the crystallization rate of component A.

[0038] According to the artificial down fiber provided by the present invention, when component A and component B are mainly composed of the same fast-crystallizing PHA and the molar contents of the repeating units contained therein are the same, the weight-average molecular weight of the fast-crystallizing PHA in component A is more than 150,000 greater than that of the fast-crystallizing PHA in component B;

[0039] Preferably, the weight-average molecular weight of the fast-crystallizing PHA in component A is 45 to 7 million, and the weight-average molecular weight of the fast-crystallizing PHA in component B is 30 to 2 million.

[0040] According to the artificial down fiber provided by the present invention, when both component A and component B are mainly composed of multiple fast-crystallizing PHAs and the proportions of the multiple fast-crystallizing PHAs in component A and component B are the same, the molecular weights of various PHAs in component A are greater than those of the corresponding same-type PHAs in component B;

[0041] Preferably, the weight-average molecular weight of each PHA in component A is more than 150,000 greater than that of the corresponding same-type PHA in component B;

[0042] Preferably, the weight-average molecular weight of the fast-crystallizing PHA in component A is 45 to 7 million, and the weight-average molecular weight of the fast-crystallizing PHA in component B is 30 to 2 million.

[0043] According to the artificial down fiber provided by the present invention, both component A and component B are mainly compositions of PLA and PHA.

[0044] According to the artificial down fiber provided by the present invention, the mass ratio of PLA in component A is more than 10% higher than the mass ratio of PLA in component B;

[0045] By adding a certain amount of PLA to both component A and component B, it helps to form better strength in the early stage of fiber forming, thereby improving the spinnability.

[0046] When the mass ratio of PLA in component A is more than 10% higher than the mass ratio of PLA in component B, there is no limitation on the types of PHA in component A and component B.

[0047] Preferably, the PHA is P34HB or P(HP-LA). At this time, the semi-crystallization time of component A can be made less than that of component B by regulating the ratio of PLA and P34HB and the molar content of 4HB in P34HB; or the semi-crystallization time of component A can be made less than that of component B by regulating the ratio of PLA and P(HP-LA) and the molar content of 3HP in P(HP-LA).

[0048] According to the artificial down fiber provided by the present invention, the mass ratio of component A to component B is 2:1 to 1:2;

[0049] Preferably, the mass ratio of component A to component B is 1.2:1 to 1:1.2.

[0050] According to the artificial down fiber provided by the present invention, in the artificial down fiber, both component A and component B contain a nano additive with a mass ratio of less than 3% and / or a silane coupling agent with a mass ratio of less than 2%.

[0051] The silane coupling agent is one or more of KH-550, KH-560, KH-570, KH-792, KH-580, KH-590, A-187, A-172, A-171, A-151, octadecyltrichlorosilane, and hexadecyltrimethoxysilane.

[0052] The nano additive includes:

[0053] Nanocellulose and nano-oxides (such as nano-zinc oxide, nano-zirconia, etc.) with a mass ratio of 1 to 3:1; wherein, the average diameter of the nanocellulose is 20 to 150 nm, the length is 1 to 5 μm, and the average particle size of the nano-oxides is less than 500 nm;

[0054] Or, silicon dioxide nanowires and nano-titanium carbide with a mass ratio of 2 to 4:2, wherein the average diameter of the silicon dioxide nanowires is less than 200 nm, the length is 1 to 5 μm, and the average particle size of the nano-titanium carbide is less than 500 nm.

[0055] The trace nano additives and silane coupling agents contained in the present invention unexpectedly enable the artificial down fiber to achieve a superhydrophobic effect. After analysis, this is due to the synergistic effect of the low surface energy substances in the coupling agent with the hydrophobicity of PHA itself and the micro-nano rough structure, which further improves the hydrophobic performance. This enables the artificial down fiber to avoid the problem of poor warmth retention after absorbing water that exists in natural down materials when in contact with water.

[0056] When the two are used in combination, their synergistic effect enables the artificial down fiber to achieve a superhydrophobic effect. Specifically: when the nano additive is used alone, the water contact angle is less than 149°, when the silane coupling agent is used alone, the water contact angle is less than 135°, and when the nano additive and the silane coupling agent are used simultaneously, the water contact angle is more than 154° (after exceeding 150° to achieve superhydrophobicity, the difficulty of increasing by 1° is more difficult than increasing by 3° between 120° and 150°).

[0057] According to the artificial down fiber provided by the present invention, the diameter of the artificial down fiber is 2 to 50 microns, and the length of the artificial down fiber is 25 to 150 mm; preferably, the crimp number of the artificial down fiber > 12 pieces / 25 mm, and the crimp rate is more than 20%; further preferably, the breaking strength of the artificial down fiber > 1.5 cN / dtex, and the breaking elongation is 20 to 70%.

[0058] The present invention also provides a preparation method of the artificial down fiber as described above. Using component A and component B as raw materials, through a bicomponent side-by-side composite spinning process, melt spinning is carried out to obtain a nascent fiber or a pre-oriented fiber, and after drawing, the artificial down staple fiber is obtained according to the staple fiber post-processing process.

[0059] The staple fiber post-processing process in the present invention refers to bundling, stretching, oiling, heat setting, cutting (including end-capping technology, as recorded in Part 5 of "The Technical Status and Development Prospect of Hollow Fibers") and packing.

[0060] The method for preparing the artificial down fiber of the present invention has a simple production process (less the "crimping" step than the traditional staple fiber process), low cost, and broad application prospects.

[0061] According to the preparation method of the artificial down fiber provided by the present invention, the spinning temperature corresponding to component A is 165 to ~220 °C, and the spinning temperature corresponding to component B is 165 to ~215 °C;

[0062] According to the preparation method of the artificial down fiber provided by the present invention, when using the melt spinning process, different cooling processes have a certain impact on the spinnability of the artificial down fiber of the present invention. When PLA is contained in component A and / or component B, a conventional cooling process can be adopted; this conventional cooling process includes: cooling the ejected fiber bundle through an annular blowing air duct with a length of 3 to 5 m.

[0063] When neither of the polymers of component A and component B contains PLA and all are PHA, the preferred cooling process includes: cooling the fiber bundle ejected from melt spinning through a water tank with a water temperature of 2 to 6 °C, and at the same time carrying out stretching to obtain the nascent fiber. Under the above melt spinning temperature and this cooling process condition, the temperature of the nascent fiber in the present invention does not have time to drop below 35 °C, but instead falls into the temperature range of 3~5 °C, which exactly meets the conditions for the rapid cooling and crystallization of PHA, thereby promoting the cooling crystallization and forming a good feedback of the material state, and can continuously carry out high-speed spinning to obtain PHA-based fibers with a cavity side-by-side structure.

[0064] Preferably, during spinning, when the twin-screw extruder melts and extrudes the spinning raw materials, the spinning temperature is: gradually increasing from the first zone to the last zone and then to the head, or remaining constant or decreasing after increasing, and the highest zone temperature appears earliest in the third zone from the bottom.

[0065] When stretching, the temperature is 70-90°C and the draw ratio is 1.3-8 times.

[0066] The heat setting temperature is 110-130°C.

[0067] The draw ratio in the present invention is related to the spinning speed of the front spinning. If the spinning speed of the front spinning is fast, the draw ratio during stretching is lower; otherwise, it is higher. Here, "lower" and "higher" are relative concepts. For example, if the spinning speed of the front spinning is 2000 m / min, the draw ratio is 1.7 times; if the spinning speed of the front spinning is 500 m / min, the draw ratio is 6 times.

[0068] Furthermore, with the gradual improvement of the melt spinning process of PHA materials, such as using P3HB4HB as the main material in Patent CN115613155B, and improving the spinnability of P3HB4HB by optimizing additives and spinning processes. When preparing the bicomponent side-by-side composite fiber with a cavity structure in the present invention, this method, including but not limited to this method, can also be used to improve the spinnability of the fiber to achieve the purpose of the present invention.

[0069] Further preferably, the melt spinning process of the present invention includes:

[0070] Using component A and component B as raw materials, spinning through a bicomponent melt spinning machine, controlling the pressure in the melt metering pump to be 7-12 MPa, cooling the ejected filament bundle through a 2 m long horizontal water tank, and simultaneously performing stretching with a draw ratio of 5 and a water temperature of 4°C to obtain a nascent filament. The obtained nascent filament is dried through a 3 m long vertical ring blowing duct and immediately oiled through an oil roller, and multiple filaments are bundled into a thread. Among them, the air supply temperature is 40-70°C, and the speed at the oil roller is 600-1000 m / min; when PLA is contained in component A and / or component B, this process is preferred.

[0071] Or, using component A and component B as raw materials, spinning through a bicomponent melt spinning machine, controlling the pressure in the melt metering pump to be 7-12 MPa, cooling the ejected filament bundle through a 4 m long vertical ring blowing duct to obtain a nascent filament; and oiling through an oil agent pump at 1-2 m, and multiple filaments are bundled into a thread. Among them, the air supply temperature is 20-50°C; when neither of the polymers of component A and component B contains PLA and all are PHA, this process is preferred.

[0072] The obtained thread is cut and packed after passing through the first godet roller, the second godet roller and the third godet roller to obtain artificial down fiber for filling; among them, the stretching and heating temperature of the first godet roller is controlled at 70-90°C and the speed is 800-1350 m / min, and the setting and heating temperature of the second godet roller is controlled at 110-130°C and the speed is 2400-4000 m / min;

[0073] An annular air blower is provided between the oil roller and the first godet roller, and the temperature is controlled at 25-35°C; stretching is generated between the first godet roller and the second godet roller, and the draw ratio is controlled to be 1.2-8 times; an annular air blower is provided between the second godet roller and the third godet roller, and the temperature is controlled at 25-38°C.

[0074] The present invention also provides the application of the artificial down fiber as described above in down filling.

[0075] A blend down fiber for filling, its preparation and application provided by the present invention, by using a bio-based degradable PHA material, a side-by-side composite fiber containing a cavity structure is prepared by melt spinning, and the composite fiber is made into an artificial down fiber through corresponding processes. The content of the PHA material in the artificial down fiber is high. The structural design of the product fully considers the crystallization characteristics of various PHA and other degradable materials, and on the basis of the self-advantages of the PHA material, in cooperation with other additives, more prominent effects are produced, such as antibacterial, anti-mite, hydrophobic, antistatic, low modulus, degradable and environmentally friendly, etc. In addition to utilizing the low thermal conductivity, hydrophobic and antibacterial and other performance advantages of the PHA-based materials themselves, especially the fiber cross-section contains a cavity structure, the fiber ends are sealed and curled, making the weight smaller and the bulkiness higher. Its warmth retention performance can reach the performance of 95% duck down / 85% goose down, and it can have both good bulkiness, stiffness and warmth retention, and is a good substitute for down, and can be mixed and applied with other down-like filling fibers.

[0076] The artificial down fiber of the present invention is not afraid of being wet by water compared with duck down and goose down, and at the same time has strong antibacterial and odor-proof properties and a long shelf life.

[0077] Since the artificial down fiber of the present invention is 100% bio-based in origin and naturally obtains a large curl ratio and cavities, it is more environmentally friendly and has better warmth retention performance than other chemical fiber artificial down.

[0078] The method for preparing the artificial down fiber of the present invention does not require processing by a crimper, has a shorter process flow and lower production cost; compared with duck down and goose down, it avoids the harm to poultry caused by "live plucking", and the material cost is also greatly reduced, realizing the application of a material that can truly replace down. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0080] Figure 1It is one of the schematic cross-sectional structures of the artificial down fiber in the present invention;

[0081] Figure 2 It is the second of the schematic cross-sectional structures of the artificial down fiber in the present invention;

[0082] Figure 3 It is the third of the schematic cross-sectional structures of the artificial down fiber in the present invention;

[0083] Figure 4 It is the fourth of the schematic cross-sectional structures of the artificial down fiber in the present invention;

[0084] Figure 5 It is the fifth of the schematic cross-sectional structures of the artificial down fiber in the present invention;

[0085] Figure 6 It is the sixth of the schematic cross-sectional structures of the artificial down fiber in the present invention;

[0086] Among them, 1: cavity structure, 2: artificial down fiber. Detailed implementation manners

[0087] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts fall within the scope of protection of the present invention.

[0088] For those not specifying specific technologies or conditions in the embodiments, they shall be in accordance with the technologies or conditions described in the literature in the field or in accordance with the product specifications. For those reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through regular channels.

[0089] The correspondence between the English abbreviations and Chinese full names in the present invention is shown in the following table:

[0090]

[0091]

[0092]

[0093] The present invention includes the following test methods:

[0094] Antibacterial test: Refer to GB / T 24253-2009 Evaluation of antibacterial properties of textiles - Part 2: Absorption method.

[0095] Anti-mite test: Refer to GB / T 24253-2009 Evaluation of anti-mite performance of textiles.

[0096] Determination of breaking strength and elongation at break: Refer to GB / T 14337-2008 Test method for tensile properties of chemical fiber staple fibers.

[0097] Skin-friendly property, water contact angle: Test according to the method in CN115613155B.

[0098] Loftiness: Test according to the method in Appendix C of GB / T 14272-2021.

[0099] Number of crimps, crimp ratio: Test according to the method in GB / T 14338-2022, where the heavy tension is set at 0.075 cN / dtex.

[0100] Initial modulus: Refer to GB / T 14337-2008 Test method for tensile properties of chemical fiber staple fibers. It represents the stiffness of the fiber (corresponding to the stiffness of the fabric). Therefore, within a certain range, the higher the value, the more rigid it is. However, if it is too high (>60 cN / dtex), it is not good and the hand feeling is stiff.

[0101] Example 1

[0102] An artificial down fiber, and its preparation process is as follows:

[0103] (1) Raw material preparation:

[0104] Component A: A mixture composed of PLA / P34HB (the mass ratio of PLA:P34HB is 8:2, the weight-average molecular weight of PLA is 110,000, the molar content of 4HB in P34HB is 2%, and the weight-average molecular weight is 830,000) and a nano-additive with a mass fraction of 0.5%;

[0105] Component B: A mixture composed of PLA / P34HB (the mass ratio of PLA:P34HB is 6:4, the weight-average molecular weight of PLA is 110,000, the molar content of 4HB in P34HB is 10%, and the weight-average molecular weight is 790,000) and a nano-additive with a mass fraction of 0.5%;

[0106] When tested at 60 °C, the semi-crystallization time t of Component A 1 / 2 is 25 s less than the semi-crystallization time t of Component B 1 / 2

[0107] The nano-additive is nano-cellulose and nano-zinc oxide with a mass ratio of 2:1. The average diameter of nano-cellulose is 50 nm, the length distribution is 1 - 3 μm, and the average particle size of nano-zinc oxide is 80 nm.

[0108] (2) Melt spinning:​

[0109] Using component A and component B as raw materials, bi-component side-by-side spinning is carried out on a bi-component melt spinning machine. The pressure in the melt metering pump is controlled at 7-12 MPa. The ejected filament bundle is cooled through a vertical annular air blowing duct with a length of 4 m, and oiling treatment is carried out by an oiling pump at 1.5 m. Multiple filaments are bundled into a filament strip. Among them, the air supply temperature is 20-50 °C; among them, the spinning temperature corresponding to component A is 175-212 °C, and the spinning temperature corresponding to component B is 172-207 °C;

[0110] The obtained filament strip is cut (including end sealing technology) and packed after passing through the first godet roller and the second godet roller to obtain artificial down fiber for filling; among them, the stretching and heating temperature of the first godet roller is controlled at 80 °C, and the speed is 1600 m / min. The setting and heating temperature of the second godet roller is controlled at 120 °C, and the speed is 3500 m / min; stretching is generated between the first godet roller and the second godet roller, and the stretching ratio is controlled at 1.2-4.

[0111] The cross-section of the obtained artificial down staple fiber is integrally in a circular ring shape. The circular ring shape is formed by splicing two semi-circular rings, and the area ratio of the cavity part of the circular ring to the total cross-sectional area is 50%. One semi-circular ring corresponds to component A, and the other semi-circular ring corresponds to component B, that is, the mass ratio of component A to component B is 1:1.

[0112] The specifications of the obtained staple fiber are 1.44 dtex, 38 mm, the strength is 3.19 cN / dtex, the breaking elongation rate is 33.8%, the short fiber is in a three-dimensional crimp structure along the fiber longitudinal direction, and the crimp number is 17.5 per 25 mm, and the crimp ratio is 35.7%;

[0113] The application performance of the obtained staple fiber is tested, and the results are as follows: its antibacterial values against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae and Candida albicans are 8.3, 8.2, 8.8, 3.7 respectively, its acarid inhibition rate is 84.6, the skin-friendly property is 4.7, the water contact angle is 148.5°, the initial modulus is 45.8 cN / dtex, the initial fluffiness of the down product made from it is 16.6 cm, and after accelerated use (after folding it in half twice, pressing it with a 1 kg flat plate with a size equivalent to the folded size for 1 min, and then unfolding the down product, regarded as 1 accelerated use) 1000 times, the fluffiness of the short fiber in it is tested to be 16.0 cm.

[0114] Example 2

[0115] An artificial down fiber, its preparation process is basically the same as that of Example 1, the difference is only that:

[0116] Component A: A mixture composed of PLA and P34HB with a mass ratio of 8:2 and a nano - additive with a mass fraction of 0.5%. Among them, the molar content of 4HB in P34HB is 2%, and the molecular weights of PLA and P34HB are the same as those in Example 1;

[0117] Component B: A mixture composed of PLA and P34HB with a mass ratio of 4:6 and a nano - additive with a mass fraction of 0.5%. The molar content of 4HB in P34HB is 10%, and the molecular weights of PLA and P34HB are the same as those in Example 1.

[0118] Under the condition of 60 °C, the semi - crystallization time \(t\) of Component A 1 / 2 is less than the semi - crystallization time \(t\) of Component B 1 / 2 by 35 s.

[0119] The spinning temperature of Component B is 168 - 198 °C.

[0120] The structure of the obtained artificial down fiber is the same as that in Example 1, but the properties of the obtained artificial down fiber are different from those in Example 1. The specific indexes of the obtained artificial down fiber are shown in Table 1.

[0121] Example 3

[0122] An artificial down fiber, and its preparation process is as follows:

[0123] (1) Raw material preparation:

[0124] Component A: A mixture composed of PLA (weight - average molecular weight is 120,000) and P(HP - LA) with a mass ratio of 7:3, where the molar content of 3HP in P(HP - LA) is 5%, the weight - average molecular weight is 750,000, a nano - additive with a mass fraction of 0.8%, and a silane coupling agent KH - 560 with a mass fraction of 0.4%;

[0125] Component B: A mixture composed of PLA (weight - average molecular weight is 120,000) and P(HP - LA) with a mass ratio of 4:6, where the molar content of 3HP in P(HP - LA) is 15%, the weight - average molecular weight is 770,000, a nano - additive with a mass fraction of 0.8%, and a silane coupling agent KH - 560 with a mass fraction of 0.4%;

[0126] Under the condition of 60 °C, the semi - crystallization time \(t\) of Component A 1 / 2 is less than the semi - crystallization time \(t\) of Component B 1 / 2 by 20 s.

[0127] The nano - additive is nano - cellulose and nano - zirconia with a mass ratio of 2:1. The average diameter of nano - cellulose is 75 nm, the length is 1 - 2.5 μm, and the average particle size of nano - zirconia is 120 nm.

[0128] (2) is basically the same as step (2) of Example 1, with the differences being that:

[0129] The spinning temperature corresponding to Component A is 178 - 208 °C, and the spinning temperature corresponding to Component B is 170 - 200 °C;

[0130] The spinning speed of the second godet roller is 2700 m / min;

[0131] The cross-section of the obtained artificial down staple fiber is generally diamond-shaped. The diamond is composed of two equilateral triangles, that is, the mass ratio of Component A to Component B is 1:1. And the cavity part of the diamond consists of 3 parts. Assuming the side length of the diamond cross-section is a, then there is an equilateral triangle cavity with a side length of 0.8a in the upper part, and two right-angled triangle cavities with a length of 0.4a and a height of 0.4√3×a in the lower part. The total area of the cavity part accounts for 64% of the total cross-sectional area.

[0132] The various indexes of the obtained staple fiber are shown in Table 1.

[0133] Example 4

[0134] An artificial down fiber, the preparation process of which is basically the same as that of Example 3, with the only difference being that:

[0135] The total area of the cavity part in the obtained artificial down staple fiber accounts for 45% of the total cross-sectional area.

[0136] The various indexes of the obtained staple fiber are shown in Table 1.

[0137] Example 5

[0138] A preparation process of an artificial down fiber is as follows:

[0139] (1) Raw material preparation:

[0140] Component A: A mixture composed of PHBHHx (the molar content of 3HHx is 5%, and the weight-average molecular weight is 2.5 million) and a nano-additive with a mass ratio of 0.6%;

[0141] Component B: A mixture composed of PHBHHx (the molar content of \alpha HHx is 5%, and the weight-average molecular weight is 0.75 million) and a nano-additive with a mass ratio of 0.6%;

[0142] When tested under the condition of 60 °C, the semi-crystallization time t of Component A 1 / 2 is 15 s less than the semi-crystallization time t of Component B 1 / 2 .

[0143] It should be noted that there seems to be a mistake in the original text where "3HHx" and "\alpha HHx" are mentioned. I translated it as it is, but it might need to be corrected according to the actual situation. Also, for the tags like 1 / 2 and 1 / 2 , they are preserved as required without further modification as they are likely specific identifiers in a particular context.The nano additive is silicon dioxide nanowires and titanium carbide nanoparticles with a mass ratio of 3:2. The average diameter of the silicon dioxide nanowires is 35 nm, the length is 1 - 2.5 μm, and the average particle size of the titanium carbide nanoparticles is 80 nm.

[0144] (2) Melt spinning:

[0145] Using component A and component B as raw materials, bi - component side - by - side spinning is carried out on a bi - component melt spinning machine. The pressure in the melt metering pump is controlled at 7 - 12 MPa. The extruded filament bundle is cooled through a 2 - m - long horizontal water tank and stretched simultaneously. The draw ratio is 5, the water temperature is 4°C, and a nascent filament is obtained. Among them, the spinning temperature corresponding to component A is 170 - 203°C, and the spinning temperature corresponding to component B is 165 - 190°C;

[0146] The obtained nascent filament is dried through a 3 - m - long vertical annular air - blowing duct and immediately oiled by an oil roller. Multiple filaments are bundled into a thread. Among them, the air - supply temperature is 40 - 70°C, and the speed at the oil roller is 800 m / min;

[0147] The obtained thread is cut (including end - sealing technology) and packed after passing through the first godet roller, the second godet roller, and the third godet roller to obtain artificial down fiber for filling. Among them, the stretching and heating temperature of the first godet roller is controlled at 80°C, and the speed is 1050 m / min. The setting and heating temperature of the second godet roller is controlled at 120°C, and the speed is 3200 m / min;

[0148] An annular air - blowing is set between the oil roller and the first godet roller, and the temperature is controlled at 25 - 35°C; stretching is generated between the first godet roller and the second godet roller, and the draw ratio is controlled at 1.3 - 4.5; an annular air - blowing is set between the second godet roller and the third godet roller, and the temperature is controlled at 25 - 38°C.

[0149] The cross - section of the obtained artificial down staple fiber is generally square. The square is composed of two rectangles spliced together. The mass ratio of component A to component B is 1.5:1, and there is a cavity part at the center of the square. The cavity structure is distributed proportionally in component A and component B (also 1.5:1), and the total area of the cavity part accounts for 30% of the total cross - sectional area.

[0150] The various indexes of the obtained staple fiber are shown in Table 1.

[0151] Example 6

[0152] An artificial down fiber, the preparation process of which is basically the same as that of Example 5, except that:

[0153] The polymer in component A is PHBHHx (the molar content of 3HHx is 5%, and the weight - average molecular weight is 7 million);

[0154] The polymer in Component B is PHBHHx (the molar content of 3HHx is 5%, and the weight-average molecular weight is 750,000).

[0155] Tested at 60 °C, the semi-crystallization time t of Component A 1 / 2 is 28 s less than the semi-crystallization time t of Component B 1 / 2 .

[0156] The spinning temperature corresponding to Component A is 175 - 206 °C, and the spinning temperature corresponding to Component B is 165 - 190 °C;

[0157] The various indexes of the obtained staple fibers are shown in Table 1 as follows:

[0158] Table 1

[0159] Example 1 2 3 4 5 6 Linear density (dtex) 1.44 1.44 1.28 1.28 2.2 2.2 Specification (mm) 38 38 90 90 76 76 Breaking strength (cN / dtex) 3.19 3.01 3.37 3.92 3.26 3.61 Elongation at break (%) 33.8 34.2 32.3 32.6 35.1 34.7 Number of crimps (per 25 mm) 17.5 19.5 19 18.5 17.5 19 Crimp ratio (%) 35.7 39.6 37.8 36.0 34.4 38.3 Antibacterial value against Escherichia coli 8.3 8.3 8.2 8.2 8.1 8.2 Antibacterial value against Staphylococcus aureus 8.2 8.1 8.1 8.1 8.0 8.0 Antibacterial value against Klebsiella pneumoniae 8.8 8.8 8.6 8.6 8.4 8.3 Antibacterial value against Candida albicans 3.7 3.6 3.4 3.5 3.4 8.4 Anti-mite inhibition rate (%) 84.6 83.1 80.6 80.9 76.7 76.4 Skin-friendly property 4.7 4.75 4.7 4.72 4.75 4.75 Water contact angle (°) 148.5 148 154.5 154 146.5 147 Initial modulus (cN / dtex) 45.8 43.9 47.2 57.5 46.1 53.0 Fluffiness before accelerated use (cm) 16.6 16.8 16.9 16.5 16.2 16.7 Fluffiness after accelerated use (cm) 16 16.3 16.5 15.8 15.7 16.2

[0160] Example 7

[0161] An artificial down fiber, the preparation process of which is basically the same as that of Example 1, except that: the area ratio of the circular cavity part to the total cross-sectional area is 80%.

[0162] The obtained staple fiber specifications are 1.44 dtex, 38 mm, the strength is only 1.35 cN / dtex, the initial modulus is only 18.7 cN / dtex, and the elongation at break is 32.4%. Although the fluffiness is 16.6 cm, the fluffiness of its down product after 6 months of normal use is 15.0 cm.

[0163] Example 8

[0164] An artificial down fiber, the preparation process of which is basically the same as that of Example 1, except that: the area ratio of the circular cavity part to the total cross-sectional area is 15%.

[0165] The obtained staple fiber specifications are 1.44 dtex, 38 mm, the crimp number is 16.5 per 25 mm, the crimp ratio is 32.1%, the fluffiness is 15.9 cm, and the fluffiness of its down product after 6 months of normal use is 15.4 cm.

[0166] Example 9

[0167] An artificial down fiber, the preparation process of which is basically the same as that of Example 1, except that: no nano-additive is added, but it is replaced by 0.6% of KH-590.

[0168] The application performance of the obtained staple fibers was tested, and the results were as follows: the antibacterial values against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae and Candida albicans were 8.1, 8.0, 8.5 and 3.6 respectively, the mite-proof inhibition rate was 81.8, the skin-friendly property was 4.72, the water contact angle was 134.5°, the fluffiness was 16.0 cm. After the down products made from it were accelerated in use (after folding it in half twice, pressing it with a 1 kg flat plate equivalent to the folded size for 1 minute, and then unfolding the down products, regarded as 1 time of accelerated use) 1000 times, the fluffiness of the staple fibers in it was tested to be 15.5 cm.

[0169] Example 10

[0170] An artificial down fiber, and its preparation process is as follows:

[0171] (1) Raw material preparation:

[0172] Component A: a mixture composed of PHB (weight average molecular weight is 1.5 million), P34HB (molar content of 4HB is 6%, weight average molecular weight is 1.1 million), PHBHHx (molar content of 3HHx is 5%, weight average molecular weight is 900,000), and a nano additive with a mass ratio of 0.6%, wherein the mass ratio of PHB, P34HB, and PHBHHx is 4:1:1;

[0173] Component B: a mixture composed of PHB (weight average molecular weight is 1 million), P34HB (molar content of 4HB is 6%, weight average molecular weight is 850,000), PHBHHx (molar content of 3HHx is 5%, weight average molecular weight is 750,000), and a nano additive with a mass ratio of 0.6%, wherein the mass ratio of PHB, P34HB, and PHBHHx is 4:1:1;

[0174] Tested under the condition of 60 °C, the semi-crystallization time t of Component A 1 / 2 is 11 s less than the semi-crystallization time t of Component B 1 / 2 .

[0175] The nano additive is nano cellulose and nano zinc oxide with a mass ratio of 2:1. The average diameter of nano cellulose is 50 nm, the length distribution is 1 - 3 μm, and the average particle size of nano zinc oxide is 80 nm.

[0176] (2) It is basically the same as step (2) of Example 5, and the differences are as follows:

[0177] The spinning temperature corresponding to Component A is 178 - 205 °C, and the spinning temperature corresponding to Component B is 168 - 197 °C;

[0178] The spinning speed of the second godet roller is 2800 m / min;

[0179] The cross-section of the obtained artificial down staple fiber is integrally circular ring-shaped. The circular ring is formed by splicing two semi-circular rings, and the area of the cavity part of the circular ring accounts for 50% of the total cross-sectional area. One semi-circular ring corresponds to component A, and the other semi-circular ring corresponds to component B, that is, the mass ratio of component A to component B is 1:1.

[0180] The specifications of the obtained staple fiber are 1.44 dtex, 38 mm, the strength is 3.35 cN / dtex, the elongation at break is 33.4%, the short fiber is in a three-dimensional crimp structure along the fiber longitudinal direction, and the crimp number is 17 per 25 mm, and the crimp ratio is 32.0%;

[0181] The application performance of the obtained staple fiber was tested, and the results were as follows: the antibacterial values against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Candida albicans were 8.4, 8.2, 8.7, and 3.7 respectively, its mite-proof inhibition rate was 82.3, the skin-friendly property was 4.78, the water contact angle was 149°, the initial modulus was 46.6 cN / dtex, the initial fluffiness of the down product made from it was 16.2 cm, and after 1000 times of accelerated use (after folding it in half twice, pressing it with a 1 kg flat plate with a size equivalent to the folded size for 1 min, and then unfolding the down product as 1 time of accelerated use), the fluffiness of the staple fiber in it was tested to be 15.6 cm.

[0182] Comparative Example 1

[0183] A preparation method of an artificial down fiber uses PLA as a raw material. The weight-average molecular weight of PLA is 110,000. Spinning is carried out using a single-component melt spinning machine to obtain a nascent filament; then the nascent filament is bundled, stretched, oiled, crimped, heat-set, cut, and packed to obtain the artificial down fiber for filling;

[0184] Among them, the spinning temperature is 180 - 220 °C; the cross-sectional shape of the nascent filament is circular.

[0185] The length of the obtained artificial down fiber is 38 mm, the fineness is 1.28 dtex, the crimp number is 11 per 25 mm, the crimp ratio is 15.8%, its antibacterial values against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Candida albicans are 4.3, 4.0, 4.1, and 1.5 respectively, its mite-proof inhibition rate is 68.2, the skin-friendly property is 4.4, the water contact angle is 131°, and the fluffiness is 7.5 cm.

[0186] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An artificial down fiber is obtained by cutting the primary fiber or pre-oriented fiber prepared by a melt spinning process after drawing. It is characterized in that, The artificial down fiber includes a bicomponent side-by-side composite fiber with a cavity structure inside, and the fiber is longitudinally in a natural curly shape as a whole; PHA is contained in both component A and component B of the bicomponent side-by-side composite fiber; the semi-crystallization time t of component A and component B of the bicomponent side-by-side composite fiber 1 / 2 is different; The PHA includes PHA copolymers and / or PHA homopolymers; The PHA copolymer has more than two comonomers, and the monomer unit includes the structure of formula (I): In formula (I), R 1 includes H or C 1-19 alkyl or alkenyl, and n is an integer from 0 to 19; each monomer unit is different from each other; The PHA homopolymer has one repeating unit, and the repeating unit includes the structure of formula (II): In formula (II), R 2 includes H or C 1-19 of an alkyl or alkenyl group, when R 2 is H, s is an integer from 0 to 3 or 5 to 19, and when R 2 is C 1-19 of an alkyl or alkenyl group, s is an integer from 0 to 19.

2. The artificial down fiber according to claim 1, wherein, The semi-crystallization time t of component A of the bicomponent side-by-side composite fiber 1 / 2 is more than 10 s less than the semi-crystallization time t of component B 1 / 2 .

3. The artificial down fiber according to claim 1, characterized in that, The cross-section of the artificial down fiber contains the cavity structure with an area ratio of 20-75%.

4. The artificial down fiber according to claim 1, characterized in that, The cavity structures are equally distributed in component A and component B.

5. The artificial down fiber according to claim 1, wherein Both component A and component B of the bicomponent side-by-side composite fiber contain PHA with a mass ratio of more than 20%.

6. The artificial down fiber according to any one of claims 1 to 5, characterized in that, Both in component A and component B, it is mainly fast-crystallizing PHA or a combination thereof; The fast-crystallizing PHA is PHB, P4HB, P3HP, P3HV, P5HV, P3HHx, P3HHp, P3HO, P3HN, P3HD or a PHA copolymer with a molar content of a repeating unit > 93%; 7. The artificial down fiber according to claim 6, characterized in that, When component A and component B are mainly composed of the same fast-crystallizing PHA and the molar content of the contained repeating units is the same, the weight-average molecular weight of the fast-crystallizing PHA in component A is more than 150,000 greater than that of the fast-crystallizing PHA in component B; Preferably, the weight-average molecular weight of the fast-crystallizing PHA in component A is 45-7,000,000, and the weight-average molecular weight of the fast-crystallizing PHA in component B is 30-2,000,000.

8. The artificial down fiber according to claim 6, characterized in that, When both component A and component B are mainly composed of multiple fast-crystallizing PHAs and the proportions of the multiple fast-crystallizing PHAs in component A and component B are the same, the molecular weight of each PHA in component A is greater than that of the corresponding same-type PHA in component B; Preferably, the weight-average molecular weight of each PHA in component A is more than 150,000 greater than that of the corresponding same-type PHA in component B; Preferably, the weight-average molecular weight of the fast-crystallizing PHA in component A is 45-7,000,000, and the weight-average molecular weight of the fast-crystallizing PHA in component B is 30-2,000,000.

9. The artificial down fiber according to any one of claims 1 to 5, characterized in that, Both component A and component B are mainly a composition of PLA and PHA.

10. The artificial down fiber according to claim 9, wherein The mass ratio of PLA in component A is more than 10% higher than that of PLA in component B.

11. The artificial down fiber according to claim 1, characterized in that, The mass ratio of component A to component B is 2:1-1:2; Preferably, the mass ratio of component A to component B is 1.2:1-1:1.

2.

12. The artificial down fiber according to any one of claims 1 to 11, characterized in that, In the artificial down fiber, both component A and component B contain a nano additive with a mass ratio of within 3% and / or a silane coupling agent with a mass ratio of within 2%.

13. The artificial down fiber according to any one of claims 1 to 12, characterized in that The diameter of the artificial down fiber is 2-50 microns, and the length of the artificial down fiber is 25-150 mm; preferably, the number of curls of the artificial down fiber > 12 per 25 mm, and the curl rate is 20% or more; further preferably, the breaking strength of the artificial down fiber > 1.5 cN / dtex, and the breaking elongation is 20-70%.

14. The preparation method of the artificial down fiber according to any one of claims 1 to 13, characterized in that, Using component A and component B as the main raw materials, a bicomponent side-by-side composite spinning process is adopted to carry out melt spinning to obtain a nascent fiber or a pre-oriented fiber, and the artificial down staple fiber is obtained according to the staple fiber post-processing process after drawing.

15. Application of the artificial down fiber according to any one of claims 1 to 13 in down filling.

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