One-step method fine denier hollow high-elastic high-crimp fiber and manufacturing method thereof

Abstract

The invention discloses a one-step method fine-denier hollow high-elastic high-crimp fiber and a manufacturing method thereof. The manufacturing method of the one-step method fine-denier hollow high-elastic high-crimp fiber comprises the following steps that a PET melt and a PBT melt are subjected to parallel composite extrusion molding through a spinneret plate; the spinneret plate is provided with a plurality of spinneret orifices, and each spinneret orifice comprises a long arc runner and a short arc runner which are asymmetrically arranged; the PET melt is extruded through the long arc runner, and the PBT melt is extruded through the short arc runner; all the short arc runners face the same direction; cooling and blowing on one side of the spinneret plate; the orientation configuration of the short arc flow channel is that cooling air is blown to one side of the short arc flow channel; oiling the extruded, cooled and molded tows; and carrying out high-speed stretching spinning on the oiled tows to obtain the fine-denier hollow high-elastic high-crimp fiber. According to the one-step fine-denier hollow high-elastic high-crimp fiber and the manufacturing method thereof, the manufactured fine-denier hollow fiber is good in elasticity and high in crimp contractility and is manufactured through the one-step method, and the post-processing and finishing process is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of fiber production, and in particular to a one-step fine-denier hollow high-elasticity high-curl fiber and a production method thereof. Background Art

[0002] The existing hollow fiber is generally made into curly yarn in two steps: first make hollow FDY filament, and then turn it into curly yarn through finishing. Specifically, the molten polyester PET melt is extruded through the C-shaped spinneret hole and expands due to the Burroughs effect, and is bonded to form a tubular fiber with a hole in the middle. Because the tensile plastic deformation during cooling is uniform, the fiber itself does not have radial stress difference after spinning, so it needs to be processed through finishing (such as false twist deformation, air deformation, small rotor deformation, friction plate deformation and sunflower wheel deformation) to become curly yarn, which is costly, long process and poor elasticity.

[0003] There are also examples of the prior art that use a one-step method to make hollow curly fibers, such as making the hollow cross-section into an "8" shape and letting the cooling air blow in from one side of the 8, which creates a cooling difference between the two ends of the 8, thereby making curly hollow fibers. However, this method can only make conventional fibers and coarse denier fibers, because the 8-shaped filament occupies too large a melt outlet area. If fine denier fibers are to be made, under the same discharge volume, only a perfect circular extrusion micropore must be set, otherwise the filaments will break and cannot be formed into fibers. Summary of the invention

[0004] In view of the deficiencies in the prior art, an object of this specification is to provide a one-step fine-denier hollow high-elasticity and high-curl fiber and a method for producing the same. The fine-denier hollow fiber has good elasticity and high curl shrinkage. It is made in a one-step method, which reduces the post-processing and finishing process.

[0005] To achieve the above purpose, the present specification provides a one-step method for producing fine-denier hollow high-elasticity and high-curl fibers, comprising the following steps: The PET melt and the PBT melt are extruded in parallel through a spinneret; the spinneret is provided with a plurality of spinneret holes, and the spinneret holes include asymmetrically arranged long arc flow channels and short arc flow channels; the PET melt is extruded through the long arc flow channels, and the PBT melt is extruded through the short arc flow channels; all the short arc flow channels are oriented in the same direction; Cooling air is blown on one side of the spinneret; the orientation of the short arc flow channel is configured such that the cooling air is blown toward one side of the short arc flow channel; Oiling the filament bundle after extrusion cooling and forming; The oiled filament bundle is stretched and spun at high speed to obtain fine-denier hollow high-elasticity and high-curl fibers.

[0006] As a preferred implementation, in the step of parallel composite extrusion molding, the spacing between the long arc flow channel and the short arc flow channel is 0.08 mm to 0.12 mm.

[0007] As a preferred embodiment, in the step of parallel composite extrusion molding, the area ratio of the long arc flow channel to the short arc flow channel is 3:1.

[0008] As a preferred embodiment, in the parallel composite extrusion molding step, the centers of a plurality of the spinnerets are located on a first circle, and the centers of the remaining plurality of the spinnerets are located on a second circle, and the first circle and the second circle are concentric circles with different diameters.

[0009] As a preferred embodiment, in the parallel composite extrusion molding step, the intrinsic viscosity of the PET melt is 0.45dL / g to 0.55dL / g, and the intrinsic viscosity of the PBT melt is 0.8dL / g to 1.25dL / g; the shrinkage rate of the PBT melt is higher than the shrinkage rate of the PET melt.

[0010] As a preferred embodiment, in the step of cooling and blowing, the blowing temperature is 15°C to 20°C.

[0011] As a preferred embodiment, the step of high-speed stretch spinning includes: the oiled filament bundle passes through the spinning channel, passes through the first network device, passes through the twisting wire guide and enters the first wire guide disk, passes through the comb-shaped wire guide after the first wire guide winding roller and then enters the second wire guide disk, passes through the second network device after the second wire guide winding roller and enters the winding machine for package forming.

[0012] As a preferred implementation, the temperature of the first godet is lower than the temperature of the second godet, and only the second godet is heated.

[0013] As a preferred embodiment, the first wire guide disk includes two first ceramic-coated hot rollers, and the two first ceramic-coated hot rollers are cross-arranged at a first predetermined angle; the filament bundle is rolled around the first wire guide disk for 5 to 7 turns; the second wire guide disk includes two second ceramic-coated hot rollers, and the two second ceramic-coated hot rollers are cross-arranged at a second predetermined angle; the filament bundle is rolled around the second wire guide disk for 5 to 6 turns; the temperature of the first ceramic-coated hot roller is lower than the temperature of the second ceramic-coated hot roller, and only the second ceramic-coated hot roller is heated.

[0014] The embodiment of this specification also provides a one-step fine denier hollow high elastic high curly fiber, which is made by the one-step fine denier hollow high elastic high curly fiber making method as described in any of the above embodiments. Beneficial Effects

[0015] The one-step method for producing fine-denier hollow high-elasticity and high-curl fibers provided in this embodiment adopts a special spinneret design, a parallel composite extrusion molding process of two different melts, a special low-temperature cooling process, and a special high-speed stretching spinning process.

[0016] First, the design of the spinneret holes on the spinneret allows PET melt and PBT melt to be extruded in parallel. The fine denier hollow is formed by extruding two different components of melt (PET melt and PBT melt) from different shaped micropores (long arc flow channel and short arc flow channel). Due to the high elasticity of the polymer, the melt will have a Bales effect after being extruded from the micropore, and the Bales effect of the PBT melt is greater than that of the PET melt, so that the arcs of the two components are in contact with each other at the connection, and are firmly bonded, which is more firm and not easy to break than the two PET component melts extruded and expanded.

[0017] Secondly, cooling and blowing are carried out on one side of the spinneret during cooling and forming, so that the cooling air is blown toward the side of the short arc flow channel. During rapid cooling, the extrusion tensile deformation rate ratio of the PBT melt is significantly greater than that of the PET melt on the leeward side. In addition, the shear rate of the PBT melt is high, and the two form a gain effect, so that the parallel filaments have potential curling internal stress, which is released in the subsequent high-temperature dyeing and finishing.

[0018] Third, in the stretching process, the present invention uses a one-step high-speed stretching method, the purpose of which is that in the high-speed stretching orientation, the molten filaments coming out of the spinneret will produce a supramolecular structure with large differences in severe stretching deformation. This supramolecular structure with large differences cannot be completed in the ordinary FDY or POY spinning process. The reason is: at a high stretching rate, the crystallization process of PET first undergoes a growth stage and then gradually decreases. The reason for this change is the local nucleation effect at a high degree of orientation. During the stretching period, the decrease in nucleation density leads to an increase in the long period, and the nucleation density is inversely proportional to the long period. This means that during the high-speed stretching period, due to the fast stretching rate, the molecular chains are rapidly oriented, forming more nucleation points, and promoting the growth of crystallization. At a low stretching rate, the crystallization process shows a monotonically decreasing trend. This shows that at a lower stretching rate, the molecular chains have more time to rearrange and adjust, but this adjustment is not always conducive to the increase of the crystallization process, but may lead to a decrease in the crystallization density. Therefore, the purpose of choosing HOY high-speed stretch spinning is to create greater radial differences. The stress stored inside the macromolecules is very different, and after releasing different stresses in post-dyeing and finishing, a radial curling shape will be produced.

[0019] Compared with the traditional hollow curly fibers, the fine denier hollow fibers produced by the production method provided in the embodiment of the present application have the following advantages: 1. The fine-denier hollow fiber produced by the present invention is composed of two components in parallel and composited, presenting an asymmetric hollow shape. The traditional curling is combined with the three-dimensional curling of the composite yarn, so the shape is more three-dimensional, fluffy and irregular; 2. The fine-denier hollow fiber produced by the present invention is a one-step finished product, which reduces the post-processing and finishing process and can reduce costs; 3. The fine-denier hollow fiber produced by the present invention is a two-component synthetic hollow fiber, in which a PBT elastic component is added, making the finished product softer and more wear-resistant; 4. The curling degree of the fine-denier hollow fiber produced by the present invention is increased by more than 80%; 5. The fine-denier hollow fiber produced by the present invention has higher hollow integrity and is not easy to break in cross section, because the PBT component has a larger Burroughs effect than PET, and is easy to form a stable bonding effect. Specifically, because PBT and PET are both common thermoplastics, they exhibit different characteristics during processing. Because the main chain of PBT molecules has changed from two methylene groups to four, the molecules are more flexible and have better processing performance, which makes PBT more prone to flow and deformation during the extrusion process, thereby exhibiting a greater extrusion growth effect. In contrast, although PET also has good processing performance, its molecular structure is different from that of PBT, resulting in a relatively small degree of deformation during the extrusion process.

[0020] The fiber provided by the present invention is a fine-denier PBT-PET composite hollow fiber, which mainly has the following characteristics: strong softness, good air permeability, strong warmth retention, long service life, and easy cleaning and drying. The molecular chain structure of PBT is similar to that of PET, but the main chain of the PBT molecule is changed from two methylene groups to four, which makes the PBT molecule more compliant and has better processing performance. This difference in molecular structure directly affects the mechanical properties of the material, including modulus. Since the molecular chain of PBT is longer and more compliant, it can deform better when subjected to force, and therefore exhibits a lower modulus. In contrast, the molecular chain of PET contains a benzene ring, and both sides of the benzene ring are directly connected to the ester group to form a conjugated structure. This structure makes PET have greater rigidity, and therefore has a higher glass transition temperature and melting point, and also leads to a higher modulus.

[0021] With reference to the following description and the accompanying drawings, the specific embodiments of the present invention are disclosed in detail, indicating the manner in which the principles of the present invention can be adopted. It should be understood that the embodiments of the present invention are not limited in scope thereby.

[0022] Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0023] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps or components. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 A flow chart of the steps of a one-step method for producing fine-denier hollow high-elasticity and high-curl fibers provided in this embodiment; Figure 2 for Figure 1 A front view of the spinneret in step S10; Figure 3 for Figure 2 A top view of Figure 4 for Figure 3 Schematic diagram of the structure of the spinneret hole; Figure 5 for Figure 2 Bottom view of Figure 6 for Figure 2 A schematic diagram of a partial cross-sectional structure; Figure 7 for Figure 1 The working diagram of step S40; Figure 8 This is a schematic structural diagram of a one-step fine-denier hollow high-elasticity high-curl fiber provided in this embodiment; Fig. 9 It is a schematic diagram of the cross-sectional structure of a one-step fine-denier hollow high-elasticity and high-curl fiber provided in this embodiment.

[0026] Description of reference numerals: 1. Spinneret; 2. Spinneret hole; 3. Long arc flow channel; 4. Short arc flow channel; 5. First guide hole; 6. Second guide hole; 7. First network device; 8. Twisted wire guide; 9. First wire guide disk; 91. First ceramic-coated hot roller; 10. Second wire guide disk; 101. Second ceramic-coated hot roller; 11. Second network device; 12. Winder; X, wind direction. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in 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 should fall within the scope of protection of the present invention.

[0028] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be another element centered thereon. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be another element centered thereon at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0030] See also Figure 1 The embodiment of the present application provides a one-step method for producing fine-denier hollow high-elasticity high-curl fiber, comprising the following steps (step S10, step S20, step S30 and step S40): Step S10: The PET melt and the PBT melt are extruded in parallel through the spinneret 1 for composite molding.

[0031] Among them, Figures 2 to 6 As shown, the spinneret 1 is provided with a plurality of spinneret holes 2, and the spinneret holes 2 include two asymmetrically arranged special-shaped units, namely, an asymmetrically arranged long arc flow channel 3 and a short arc flow channel 4. The PET melt is extruded through the long arc flow channel 3, and the PBT melt is extruded through the short arc flow channel 4. Figure 3 As shown, all the short arc flow channels 4 are oriented in the same direction and directly face the wind direction X.

[0032] Specifically, Figure 4As shown, the spacing between the long arc flow channel 3 and the short arc flow channel 4 is 0.08mm~0.12mm. The area ratio of the long arc flow channel 3 and the short arc flow channel 4 is 3:1. This application needs to produce fine denier hollow fibers, so the cross-section of the spinneret hole 2 must meet the characteristics of small area. The multi-circle composite mode cannot produce fine denier fibers and cannot be formed. The design of the spinneret hole 2 allows the PET melt and the PBT melt to be extruded in parallel.

[0033] like Figure 3 As shown, the centers of the plurality of spinnerets 2 are located on the first circle, and the centers of the remaining plurality of spinnerets 2 are located on the second circle, and the first circle and the second circle are concentric circles with different diameters, that is, the distribution of the spinnerets 2 is concentric circle distribution, but all the short arc flow channels 4 are oriented in the same direction, toward the cooling and blowing side (see step S20 below for details). The parallel composite hollow fiber is made of two fiber-forming polymers PET melt and PBT melt with different intrinsic viscosities, crystallization rates and shrinkage rates.

[0034] The intrinsic viscosity of the PET melt is 0.45 dL / g to 0.55 dL / g, and the intrinsic viscosity of the PBT melt is 0.8 dL / g to 1.25 dL / g. The fine denier hollow is formed by extruding two different components of melt (PET melt and PBT melt) from different shaped micropores (long arc flow channel 3 and short arc flow channel 4). Due to the high elasticity of the polymer, the melt will have a Bales effect after being extruded from the micropore, and the Bales effect of the PBT melt is greater than that of the PET melt, so that the arcs of the two components are in contact with each other at the connection, melted and bonded firmly, which is more firm and not easy to break than the two PET component melts extruded and expanded.

[0035] Figure 3 and Figure 5 They are respectively a top view and a bottom view of the spinneret 1, Figure 5 The first guide hole 5 corresponds to the long arc flow channel 3, and the second guide hole 6 corresponds to the short arc flow channel 4. Figure 6 As shown, the first guide hole 5 conducts the long arc flow channel 3 on the upper surface of the spinneret 1 to the lower surface of the spinneret 1, and the second guide hole 6 conducts the short arc flow channel 4 on the upper surface of the spinneret 1 to the lower surface of the spinneret 1. On the horizontal plane, the shape of the first guide hole 5 is similar to that of the long arc flow channel 3, and the shape of the second guide hole 6 is similar to that of the short arc flow channel 4. The first guide hole 5 and the second guide hole 6 gradually shrink from top to bottom. Figure 5 The circle in the figure is only used to indicate the position and does not represent the actual shape of the first guide hole 5 and the second guide hole 6.

[0036] Step S20: Cooling and blowing are performed on one side of the spinneret 1.

[0037] Among them, the wind direction X is Figure 3As shown, the orientation of the short arc flow channel 4 is configured to make the cooling air blow to one side of the short arc flow channel 4. The cooling process used in this application is a specific low-temperature side blowing cooling. At present, the conventional air cooling methods are basically ring blowing methods, the blowing direction is 360-degree ring blowing, and the blowing temperature is 20°C~25°C. The cooling method provided by the present invention is a side blowing method, and the blowing temperature is 15°C~20°C. Specifically, the cooling temperature can be reduced to the set value by using the cooling water of the public refrigeration to the evaporation heat exchange mode of the spinning workshop.

[0038] The cooling forming selects cooling blowing on one side of the spinneret 1, so that the cooling air is blown to the side of the short arc flow channel 4. During the rapid cooling, the extrusion tensile deformation speed ratio of the PBT melt is significantly greater than that of the PET melt on the leeward side. In addition, the shear rate of the PBT melt is high, and the two form a gain effect, so that the parallel filaments have potential curling internal stress, which is released in the subsequent high-temperature dyeing and finishing.

[0039] In addition, the shrinkage performance of PBT and PET in parallel composite spinning is different, mainly due to the differences in their chemical structure and physical properties. PBT and PET are both thermoplastic polyesters with similar chemical structure basis, but the shrinkage of PBT is relatively high (that is, the shrinkage of the PBT melt is higher than the shrinkage of the PET melt). This difference stems from the different molecular chain structures and thermal properties of the two polymers, which leads to different shrinkage behaviors during heat treatment. Specifically, the shrinkage of the PBT component is higher, while the shrinkage of the PET component is relatively low. This difference in shrinkage causes the PBT / PET parallel composite fibers to produce permanent curling toward the PBT side. This curling morphology is not only beneficial to improving the cohesion of the fibers, but also helps to improve the textile processing performance and wearing performance. The combined increase of the above two benefits will eventually lead to a parallel composite hollow high-curl fiber state.

[0040] Step S30: oiling the filament bundle after extrusion, cooling and forming.

[0041] Specifically, the filament bundles after extrusion cooling and forming can be bundled and oiled through an oil nozzle.

[0042] Step S40: The oiled filament bundle is subjected to high-speed stretching and spinning to obtain fine-denier hollow high-elasticity and high-curl fibers.

[0043] Specifically, Figure 7 As shown, step S40 includes: the oiled filament bundle passes through the spinning channel, passes through the first network device 7, passes through the twisting wire guide 8 and enters the first wire guide disk 9, after being rolled on the first wire guide disk 9, passes through the comb-shaped wire guide and then enters the second wire guide disk 10, after being rolled on the second wire guide disk 10, passes through the second network device 11 and then enters the winding machine 12 for package forming.

[0044] Among them, the temperature of the first wire guide disk 9 is lower than the temperature of the second wire guide disk 10, and only the second wire guide disk 10 is heated. The first wire guide disk 9 is a cold disk and is not heated. By heating the second wire guide disk 10, the violent shaking of the yarn bundle caused by the large radial stress difference can be eliminated, and the spinning production can be stabilized.

[0045] Specifically, the first wire guide disc 9 includes two first ceramic-coated hot rollers 91, which are arranged crosswise at a first predetermined angle, and can divide the wire path so that the wire bundle can be rolled around the first wire guide disc 9 for 5 to 7 turns. The second wire guide disc 10 includes two second ceramic-coated hot rollers 101, which are arranged crosswise at a second predetermined angle. The wire bundle is rolled around the second wire guide disc 10 for 5 to 6 turns. The temperature of the first ceramic-coated hot roller 91 is lower than that of the second ceramic-coated hot roller 101, and only the second ceramic-coated hot roller 101 is heated.

[0046] In the stretching process, the present invention uses a one-step high-speed stretching method, the purpose of which is that in the high-speed stretching orientation, the molten filaments exiting the spinneret 1 will produce a highly different supramolecular structure during the severe stretching deformation. Such a highly different supramolecular structure cannot be achieved in the ordinary FDY or POY spinning process. The reason is: At high stretching rates, the crystallization process of PET first goes through a growth phase, which then gradually decreases. The reason for this change is the local nucleation effect at high orientation. During the stretching period, the decrease in nucleation density leads to an increase in the long period, and the nucleation density is inversely proportional to the long period. This means that during the high-speed stretching period, due to the fast stretching rate, the molecular chains are quickly oriented, forming more nucleation points, which promotes the growth of crystallization.

[0047] At low stretching rates, the crystallization process shows a monotonically decreasing trend. This indicates that at lower stretching rates, the molecular chains have more time to rearrange and adjust, but this adjustment is not always conducive to the increase of the crystallization process, but may lead to a decrease in crystal density. Therefore, the purpose of choosing HOY high-speed stretch spinning is to create greater radial differences. The stress stored in the macromolecules is very different, and after releasing different stresses in post-dyeing and finishing, radial curling will be produced.

[0048] See also Figure 8 and Fig. 9The present application also provides a one-step fine-denier hollow high-elastic high-curl fiber, which is produced by any one of the above one-step fine-denier hollow high-elastic high-curl fiber production methods. The implementation of the one-step fine-denier hollow high-elastic high-curl fiber corresponds to the implementation of the above production method, which can solve the technical problems solved by the production method implementation method and achieve the technical effects of the production method implementation method accordingly. The specific application will not be repeated here.

[0049] Compared with the traditional hollow curly fibers, the fine denier hollow fibers produced by the production method provided in the embodiment of the present application have the following advantages: 1. The fine-denier hollow fiber produced by the present invention is composed of two components in parallel and composited, presenting an asymmetric hollow shape. The traditional curling is combined with the three-dimensional curling of the composite yarn, so the shape is more three-dimensional, fluffy and irregular; 2. The fine-denier hollow fiber produced by the present invention is a one-step finished product, which reduces the post-processing and finishing process; 3. The fine-denier hollow fiber produced by the present invention is a two-component synthetic hollow fiber, in which a PBT elastic component is added, making the finished product softer and more wear-resistant; 4. The curling degree of the fine-denier hollow fiber produced by the present invention is increased by more than 80%; 5. The fine-denier hollow fiber produced by the present invention has higher hollow integrity and is not easy to break in cross section, because the PBT component has a larger Burroughs effect than PET, and is easy to form a stable bonding effect. Specifically, because PBT and PET are both common thermoplastics, they exhibit different characteristics during processing. Because the main chain of PBT molecules has changed from two methylene groups to four, the molecules are more flexible and have better processing performance, which makes PBT more prone to flow and deformation during the extrusion process, thereby exhibiting a greater extrusion growth effect. In contrast, although PET also has good processing performance, its molecular structure is different from that of PBT, resulting in a relatively small degree of deformation during the extrusion process.

[0050] The fiber provided by the present invention is a fine-denier PBT-PET composite hollow fiber, and its main features include strong softness, good air permeability, strong warmth retention, long service life, and easy cleaning and drying. The molecular chain structure of PBT is similar to that of PET, but the main chain of the PBT molecule is changed from two methylene groups to four, which makes the PBT molecule more compliant and has better processing performance. The difference in this molecular structure directly affects the mechanical properties of the material, including modulus. Since the molecular chain of PBT is longer and more compliant, it can be better deformed when subjected to force, and therefore exhibits a lower modulus. In contrast, the molecular chain of PET contains a benzene ring, and the two sides of the benzene ring are directly connected to the ester group to form a conjugated structure. This structure makes PET have greater rigidity, and therefore has a higher glass transition temperature and melting point, and also leads to a higher modulus.

[0051] The characteristics of polyester (PET) fiber mainly include: 1. Good wrinkle resistance and shape retention: Clothes made of polyester fiber are not easy to wrinkle during wearing and can maintain the original shape of the clothes; 2. High strength and strong elastic recovery ability: Polyester fiber has high strength and elastic recovery ability, making the woven fabric strong and durable, and can quickly restore to its original shape; 3. Anti-wear and non-sticky hair: Polyester fiber also has the characteristics of anti-wear and non-sticky hair, making the fabric look neater; 4. Easy to clean and quick-drying: Polyester fiber products are easy to clean and dry quickly, suitable for various outdoor activities and daily use; 5. Corrosion resistance: It has good corrosion resistance and can maintain its performance and appearance in different environments; 6. Dyeability: Generally, disperse dyes are used for dyeing, high temperature and high pressure dyeing is adopted, and the dyeing performance is good. In summary, polyester fiber is widely used in textile and clothing manufacturing due to its excellent physical and chemical properties, bringing a lot of convenience and comfort to people's daily life.

[0052] The characteristics of PBT fiber mainly include: 1. Good stretch and resilience: PBT fiber is easy to stretch and can immediately rebound to its original shape, providing a comfortable fit. This fiber is easy to curl, has good durability and dimensional stability, and its elasticity is not affected by changes in ambient temperature; 2. Excellent dyeing performance: PBT polyester fiber can be dyed at a lower temperature under normal pressure without chemical carriers, and the optimal dyeing temperature is 110-120°C. At boiling point, the fiber can be fully colored and has good water fastness; 3. Good dimensional stability: PBT polyester fiber has the dimensional stability of polyester and the softness of nylon, making its fabric have a natural and comfortable feel; 4. Excellent color fastness: PBT polyester fiber can withstand repeated washing in sea water and swimming pool water, and the fabric is not easy to fade, and it is bright and vivid for a long time. In particular, PBT fiber has excellent chlorine resistance; 5. Good durability, dimensional stability, good elasticity: these properties make PBT fiber widely used in high-end clothing, sportswear and other fields, such as swimsuits, pajamas, underwear, women's tights, etc., to achieve the excellent effect of comfortable wearing and soft touch; 6. Elasticity is not affected by humidity. In addition, PBT fiber also has excellent resilience, mildew and moth resistance, good curl elasticity, antistatic properties, and a wool-like feel, which makes it have a wide range of application prospects in the textile industry.

[0053] In contrast, the one-step fine denier hollow high elastic high curl fiber provided by the present invention has the following characteristics: ① Good elasticity: The PBT component in the fine-denier PBT-PET composite hollow fiber of the present invention has good elasticity because its molecular formula is [(CH2)4OOCC6H4COO]n, and there are two more methylene groups in its molecular chain, which makes the main chain structure of the methylene molecules of PBT spiral, similar to the molecular structure of nylon, and the methylene chain segment is longer than PET. This structure gives the fiber of the present invention excellent tensile and compressive elasticity and wrinkle resistance, and its elasticity is similar to that of nylon. The elastic recovery rate of polyester is 20%~50%, and it has good resilience. When it is elongated by 2%, the elastic recovery rate is 97%; when it is elongated by 4%, the elastic recovery rate is 90%; when it is elongated by 8%, the elastic recovery rate is 67%. When the fiber of the present invention is elongated by 3%~6%, its elastic recovery rate is close to 100%; when the fiber of the present invention is elongated by 8%, the elastic recovery rate is 92%~99%.

[0054] ② High curling shrinkage: The fine-denier PBT-PET composite hollow fiber of the present invention has a special two-component structure, annular compound of PBT and PET, single-sided low-temperature blowing, rapid cooling difference, high-speed stretching orientation crystallization difference, resulting in a huge potential stress difference in the radial direction of the fiber. Finally, after the stress is released in the subsequent dyeing and finishing, the fiber curls in three-dimensional space more than ordinary two-component elastic fibers and ordinary shrinkage fibers. Curl is an indicator to measure the degree of fiber curling, usually expressed as the percentage of the difference (L-L0) between the straight length L and the curl length L0 of the curled fiber to the straight length L. This indicator is closely related to the spinning performance of the fiber. Increasing the curl can improve the fiber cohesion and thus improve the quality of the spun yarn. The curl of general curled yarn is usually between 10.0% and 15.0%, while the curl of the present invention can reach more than 30%.

[0055] ③ Strong softness: The fine-denier PBT-PET composite hollow fiber of the present invention has a unique hollow structure and the addition of PBT components. Because the molecular chain of PBT is more rigid and the molecular chain of PET is more flexible, the fiber is relatively soft and comfortable to wear, providing a good wearing experience.

[0056] ④Good air permeability: There are many small holes inside the fine-denier PBT-PET composite hollow fiber of the present invention, which not only help to keep warm, but also ensure good air permeability, avoiding the feeling of airtightness and dampness caused by long-term wearing.

[0057] ⑤ Strong warmth retention: The hollow structure of the fine-denier PBT-PET composite hollow fiber of the present invention makes it have good warmth retention, and is suitable for making winter clothing or outdoor products in cold environments.

[0058] ⑥ Long service life: The fine-denier PBT-PET composite hollow fiber of the present invention has good wear resistance, is more durable than ordinary polyester fiber, has a longer service life of the fabric, and also has good wrinkle resistance and anti-pilling properties.

[0059] ⑦Easy to clean and dry: Like other fabrics, fine-denier PBT-PET composite hollow fiber fabric only needs a slight cleaning to easily remove dirt and stains, and is not easy to deform and fade. It is even drier and softer after drying.

[0060] These characteristics make fine-denier PBT-PET composite hollow fibers have broad application prospects in many fields such as clothing and household items.

[0061] It should be noted that, in the description of this specification, the terms "first", "second", etc. are only used for descriptive purposes and to distinguish similar objects. There is no order of precedence between the two, and they cannot be understood as indicating or implying relative importance. In addition, in the description of this specification, unless otherwise specified, the meaning of "plurality" is two or more.

[0062] Any numerical value cited herein includes all values ​​of lower and upper values ​​that increase by one unit from the lower limit to the upper limit, and there is at least a two-unit interval between any lower value and any higher value. For example, if the value of the quantity of a component or a process variable (such as temperature, pressure, time, etc.) is set forth to be from 1 to 90, preferably from 20 to 80, and more preferably from 30 to 70, the purpose is to illustrate that values ​​such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also explicitly listed in the specification. For values ​​less than 1, one unit is appropriately considered to be 0.0001, 0.001, 0.01, 0.1. These are merely examples that are intended to be clearly expressed, and it can be considered that all possible combinations of numerical values ​​listed between the lowest value and the highest value are clearly set forth in the specification in a similar manner.

[0063] Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. "About" or "approximately" used with a range applies to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", including at least the specified endpoints.

[0064] All articles and references disclosed, including patent applications and publications, are incorporated herein by reference for all purposes. The term "consisting essentially of..." to describe a combination should include the identified elements, ingredients, parts or steps and other elements, ingredients, parts or steps that do not substantially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe a combination of elements, ingredients, parts or steps herein also contemplates embodiments that consist essentially of these elements, ingredients, parts or steps. By using the term "may", it is intended to indicate that any attribute described that "may" include is optional.

[0065] Multiple elements, ingredients, parts or steps can be provided by a single integrated element, ingredient, part or step. Alternatively, a single integrated element, ingredient, part or step can be divided into separate multiple elements, ingredients, parts or steps. The disclosure "one" or "an" used to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

[0066] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but should be determined with reference to the appended claims and the full scope of equivalents possessed by such claims. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a waiver of the subject matter, nor should it be considered that the inventors did not consider the subject matter to be part of the disclosed inventive subject matter.

Claims

1. A one-step method for producing fine-denier hollow high-elastic high-curl fiber, characterized in that: The following steps are involved: The PET melt and the PBT melt are extruded in parallel through a spinneret; the spinneret is provided with a plurality of spinneret holes, and the spinneret holes include asymmetrically arranged long arc flow channels and short arc flow channels; the PET melt is extruded through the long arc flow channels, and the PBT melt is extruded through the short arc flow channels; All the short arc flow channels are oriented in the same direction; Cooling air is blown on one side of the spinneret; the orientation of the short arc flow channel is configured such that the cooling air is blown toward one side of the short arc flow channel; Oiling the filament bundle after extrusion cooling and forming; The oiled filament bundle is stretched and spun at high speed to obtain fine-denier hollow high-elasticity and high-curl fibers.

2. The one-step method for producing fine denier hollow high-elasticity and high-curl fiber according to claim 1, characterized in that: In the step of parallel composite extrusion molding, the spacing between the long arc flow channel and the short arc flow channel is 0.08 mm to 0.12 mm.

3. The one-step method for producing fine denier hollow high-elastic high-curl fiber according to claim 1, characterized in that: In the step of parallel composite extrusion molding, the area ratio of the long arc flow channel to the short arc flow channel is 3:

1.

4. The one-step method for producing fine denier hollow high-elasticity and high-curl fiber according to claim 1, characterized in that: In the step of parallel composite extrusion molding, the centers of a plurality of the spinnerets are located on a first circle, and the centers of the remaining plurality of the spinnerets are located on a second circle, and the first circle and the second circle are concentric circles with different diameters.

5. The one-step method for producing fine denier hollow high-elasticity and high-curl fiber according to claim 1, characterized in that: In the step of parallel composite extrusion molding, the intrinsic viscosity of the PET melt is 0.45 dL / g to 0.55 dL / g, and the intrinsic viscosity of the PBT melt is 0.8 dL / g to 1.25 dL / g; the shrinkage rate of the PBT melt is higher than that of the PET melt.

6. The one-step method for producing fine denier hollow high-elasticity and high-curl fiber according to claim 1, characterized in that: In the step of cooling and blowing, the blowing temperature is 15°C to 20°C.

7. The one-step method for producing fine denier hollow high-elasticity and high-curl fiber according to claim 1, characterized in that: The steps of high-speed stretch spinning include: the oiled filament bundle passes through the spinning channel, passes through the first network device, passes through the twisting wire guide device and enters the first wire guide disk, passes through the comb-shaped wire guide after the first wire guide winding roller and then enters the second wire guide disk, passes through the second network device after the second wire guide winding roller and enters the winding machine for package forming.

8. The one-step method for producing fine denier hollow high-elasticity and high-curl fiber according to claim 7, characterized in that: The temperature of the first godet is lower than that of the second godet, and only the second godet is heated.

9. The one-step method for producing fine denier hollow high-elasticity and high-curl fiber according to claim 8, characterized in that: The first wire guide disk includes two first ceramic-coated hot rollers, which are cross-arranged at a first predetermined angle; the filament bundle is rolled around the first wire guide disk for 5 to 7 turns; the second wire guide disk includes two second ceramic-coated hot rollers, which are cross-arranged at a second predetermined angle; the filament bundle is rolled around the second wire guide disk for 5 to 6 turns; the temperature of the first ceramic-coated hot roller is lower than that of the second ceramic-coated hot roller, and only the second ceramic-coated hot roller is heated.

10. A one-step fine denier hollow high elastic high curl fiber, characterized in that: The one-step fine-denier hollow high-elasticity and high-curl fiber is produced by the one-step fine-denier hollow high-elasticity and high-curl fiber production method according to any one of claims 1 to 9.

Images