Three-component helical auxetic yarn based on ring spinning, and preparation method therefor

Abstract

The present invention belongs to the technical field of yarns, and relates to a three-component helical auxetic yarn based on ring spinning, and a preparation method therefor. The three-component helical auxetic yarn of the present invention comprises a core yarn, a first wrapping yarn and a second wrapping yarn, wherein the core yarn is made of elastic filaments, the first wrapping yarn is made of staple fibers, and the second wrapping yarn is made of non-elastic filaments; the first wrapping yarn is obtained by wrapping the staple fibers around the surface of the core yarn, and the second wrapping yarn is obtained by wrapping the non-elastic filaments around the surfaces of the core yarn and the first wrapping yarn; and the core yarn, the first wrapping yarn and the second wrapping yarn are formed in one step by means of a spinning frame. The three-component helical auxetic yarn exhibits the maximum negative Poisson's ratio effect, has a good and stable negative Poisson's ratio effect, and can not only improve the performance of textile materials, but also has broad application prospects in the fields of protective clothing, biomedical materials, sensors, etc.

Description

A three-component spiral auxetic yarn based on ring spinning and its preparation method Technical Field

[0001] The present invention belongs to the technical field of yarns, and in particular relates to a three-component spiral auxetic yarn based on ring spinning and a preparation method thereof. Background Art

[0002] Conventional materials typically exhibit a positive Poisson's ratio when stretched, while new auxetic materials exhibit a negative Poisson's ratio, also known as negative Poisson's ratio materials. This refers to the fact that when stretched (compressed), the material expands (contracts) laterally within its elastic range. The larger the absolute value of the negative Poisson's ratio, the more pronounced the material's auxetic effect. In recent years, in-depth research has revealed that in addition to possessing the geometric deformation characteristics of a negative Poisson's ratio, they also possess excellent physical and mechanical properties such as shear resistance, fracture resistance, and energy absorption. Combining auxetic materials with textiles is an emerging research direction that not only improves the performance of textile materials but also has broad application prospects in fields such as protective clothing, biomedical materials, and sensors. Research on auxetic textile materials has achieved certain progress and results in the fields of fibers, yarns, fabrics, and nonwovens.

[0003] Existing auxetic yarns primarily consist of a spirally wrapped structure formed by highly elastic filaments and non-elastic materials. This structure is subject to slippage between the components, resulting in insufficient yarn stability. Furthermore, the non-elastic raw materials are mostly filaments. While filaments offer excellent physical properties, they lack the curly, fluffy surface and wearability of staple fibers, limiting the application and scope of textiles made from auxetic yarns. The addition of staple fibers stabilizes the auxetic yarn structure, reduces filament slippage within the yarn, and significantly improves its wearability and range of applications. Patent CN201710539952.4 and Patent CN201710539986.3 add a cone-type composite spinning device to the spinning frame, use filament and twisted staple fiber sliver as raw materials, and synthesize negative Poisson's ratio yarn through a wire ring spindle. The staple fiber sliver is not drafted by the rollers of ring spinning, and belongs to the category of simple twisting using the twisting mechanism of ring spinning. At the same time, the use of twisted staple fiber sliver as the yarn core weakens the negative Poisson's ratio effect of the yarn. At the same time, the secondary twisted staple fiber weakens its wearability such as feel and softness. Patent CN201710585143.7 relates to a core-spun wrapped filament staple composite yarn and a production device. Ring spinning can be used to stretch staple fiber strips and then twist them together with double filaments to form yarn. However, if the performance of the two groups of filaments is very different and the stretching tension requirements are different, they cannot be controlled separately, and thus normal spinning cannot be achieved. The yarn tension of the high-elastic filaments and the inelastic filaments of the elastomeric yarn is very different, and the equipment cannot be used to achieve the production of elastomeric yarn composed of staple fibers, high-elastic filaments and inelastic filaments.

[0004] Therefore, the existing spinning devices and methods for traction yarns are still immature, and it is necessary to break through the limitations in raw material selection, yarn structure and spinning process manufacturing, and produce yarns with excellent traction effect to promote their wide application in various fields.

[0005] Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a three-component spiral auxetic yarn composed of elastic filaments / short fibers / inelastic filaments based on ring spinning and a preparation method thereof, so as to improve the wearability and application range of the auxetic yarn and its fabrics.

[0007] The first object of the present invention is to provide a three-component spiral expansion yarn based on ring spinning, comprising a core yarn, a first wrapping yarn and a second wrapping yarn; the core yarn is an elastic filament, the first wrapping yarn is a staple fiber, and the second wrapping yarn is an inelastic filament; the first wrapping yarn is obtained by wrapping the staple fiber around the surface of the core yarn, and the second wrapping yarn is obtained by wrapping the inelastic filament around the surface of the core yarn and the first wrapping yarn, and the core yarn, the first wrapping yarn and the second wrapping yarn are formed in one step by a spinning frame.

[0008] In one embodiment of the present invention, the elastic filaments are selected from one or more of polyurethane elastic fibers, diene elastic fibers and polyetherester elastic fibers.

[0009] In one embodiment of the present invention, the staple fibers are selected from one or more of cotton fibers, wool fibers, linen fibers, viscose fibers and polyester fibers.

[0010] In one embodiment of the present invention, the non-elastic filaments are selected from one or more of polyester fibers, polyamide fibers, aromatic polyamide fibers and metal wires.

[0011] In one embodiment of the present invention, the total fineness of the elastic filaments in the three-component spiral auxetic yarn is 70%, the total fineness of the staple fibers is 1%-30%, and the total fineness of the inelastic filaments is 1%-30%.

[0012] In one embodiment of the present invention, the twist coefficient of the three-component spiral auxetic yarn is 300-375.

[0013] In one embodiment of the present invention, the twist direction of the three-component spiral auxetic yarn is Z twist or S twist.

[0014] The second object of the present invention is to provide a method for preparing the three-component spiral tensile yarn based on ring spinning, which uses a spinning frame as a generating device, including a ring spinning frame, a filament feeding device (to control filament unwinding) and a pre-stretching device (to control filament tension), and the filament feeding device and the pre-stretching device are arranged on the ring spinning frame. The preparation method includes the following steps, in which short fibers and non-elastic filaments are sequentially wrapped around elastic filaments through the spinning frame to obtain the three-component spiral tensile yarn based on ring spinning.

[0015] In one embodiment of the present invention, during the production process, the draft ratios of the elastic and inelastic filaments are independently 1.01-1.20. The specific optimal values ​​are affected by factors such as raw material properties. The draft ratios of the elastic and inelastic filaments affect the negative Poisson's ratio of the yarn. During the feeding process, the elastic and inelastic filaments are each controlled by their own godet rollers. The speeds of the front roller and the godet rollers are unequal. The ratio of these speeds is called the draft ratio.

[0016] In one embodiment of the present invention, during the preparation process, the drafting ratio of the staple fibers in the front zone is 15-50, and the drafting ratio in the back zone is 1.1-1.4. The total drafting ratio can be flexibly configured according to the roving quantity and the proportion of the staple fibers in the axially expanded yarn; the roving is the product of the preceding process of the spun yarn (the final product), and is therefore the raw material of the staple fibers in this process: that is, the staple fiber roving → the spun yarn (the staple fiber portion in the axially expanded yarn).

[0017] In one embodiment of the present invention, during the production process, the elastic filaments and the inelastic filaments are fed at intervals of 3 mm to 5 mm at the front nip of the front roller, while the staple fibers and the elastic filaments are fed at the front nip of the front roller without any intervals, i.e., with an interval of 0 mm.

[0018] In one embodiment of the present invention, the drafting can be performed by three-roller long and short rubber ring drafting or four-roller double short rubber ring drafting.

[0019] The technical solution of the present invention has the following advantages over the prior art:

[0020] (1) The three-component spiral axial tension yarn described in the present invention adopts a wide range of fibers and filaments, and the proportion of short fiber components can also be flexibly adjusted. The use of short fibers as the first wrapping yarn alleviates the defect that the elastic filaments and the non-elastic filaments are directly wrapped, which causes the wrapping components to slide along the yarn surface, thereby improving the stability of the yarn structure. In addition, the addition of short fibers gives the axial tension yarn excellent properties such as softness that long filaments cannot achieve, thereby expanding the application scenarios of the axial tension yarn.

[0021] (2) The principle of the negative Poisson's ratio effect produced by the three-component spiral auxetic yarn described in the present invention is that due to the large performance differences between the three components of elastic filaments / staple fibers / inelastic filaments, under a small tensile strain, the elastic filaments buckle under the combined action of the wrapped staple fibers and the wrapped inelastic filaments, and the yarn initially produces a negative Poisson's ratio effect. With further stretching, the core filaments and the wrapped components exchange positions, and the yarn exhibits the maximum negative Poisson's ratio effect. It has a good and stable negative Poisson's ratio effect, which can not only improve the performance of textile materials, but also has broad application prospects in the fields of protective clothing, biomedical materials, and sensors.

[0022] (3) The three-component spiral flexographic yarn described in the present invention is formed in one step through a modified spinning frame, thereby improving production efficiency and production continuity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0024] FIG1 is a structural deformation diagram of the three-component spiral auxetic yarn of elastic filament / short fiber / non-elastic filament of the present invention;

[0025] FIG2 is a diagram of a spinning apparatus for a three-component spiral auxetic yarn of elastic filaments / short fibers / non-elastic filaments according to the present invention;

[0026] FIG3 is an axial tensile deformation diagram of the three-component spiral auxetic yarn of elastic filament / short fiber / non-elastic filament according to the present invention;

[0027] FIG4 is a Poisson's ratio curve of the elastic filament / staple fiber / non-elastic filament three-component spiral auxetic yarn of the present invention;

[0028] Explanation of the figure marks: 1-1 is elastic filament, 1-2 is staple fiber, 1-3 is non-elastic filament, 2-1 is non-elastic filament, 2-2 is staple fiber, 2-3 is elastic filament, 2-4 is tension plate, 2-5 is the first guide roller, 2-6 is the second guide roller, 2-7 is the double-groove guide wheel, 2-8 is the back roller, 2-9 is the middle roller, 2-10 is the front roller, 2-11 is the three-component spiral tensioned yarn of elastic filament / staple fiber / non-elastic filament. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0030] In the present invention, unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art of the technical field of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0031] In the present invention, unless otherwise specified, the drafting in the embodiments adopts three-roller long and short apron drafting.

[0032] In the present invention, unless otherwise specified, the short fibers and elastic filaments in the embodiments are fed without spacing at the front nip of the front roller, that is, the spacing is 0 mm.

[0033] Example 1

[0034] 1 , the present invention relates to a three-component spiral auxetic yarn based on ring spinning and a preparation method thereof. An improved spinning frame is used as a generating device ( FIG. 2 ). A feeding mechanism for controlling filament unwinding and a pre-drafting mechanism for controlling filament tension are added to a conventional ring spinning frame. The preparation method comprises the following steps:

[0035] The non-elastic filament 2-1 is placed on a top-mounted creel and is unwound axially. It passes through the tension plate 2-4 on the top, the first guide roller 2-5 and the double-groove guide wheel 2-7 on the bottom, and then is fed into the front roller 2-9.

[0036] The elastic filament 2-3 is placed on the second godet roller 2-6 and is actively unwound and fed into the front roller 2-9 through the double-groove godet wheel 2-7.

[0037] After the staple fiber 2-2 is stretched by the rear roller 2-8, the middle roller 2-9 and the front roller 2-10, it intersects with the elastic filament and the inelastic filament at the front jaw of the front roller 2-10, is pulled and combined by the wire ring, and then twisted into yarn, and finally wound onto the yarn tube to form a three-component spiral expansion yarn 2-11 of elastic filament / stab fiber / inelastic filament. The specific structure is shown in Figure 1. The core yarn of the yarn is the elastic filament 1-1 in a straight state, and the staple fiber 1-2 is used as the first wrapping component to realize the first layer of wrapping on the core yarn, and the inelastic filament 1-3 is used as the second wrapping component to wrap the elastic filament 1-1 and the staple fiber 1-2.

[0038] The Poisson's ratio of a material is expressed as the negative value of the ratio of the strain perpendicular to the load direction to the strain along the load direction, that is: ε x =(D-D0) / D0

[0039] ε x - Yarn diameter change rate perpendicular to the load direction;

[0040] ε y - yarn elongation in the direction of load;

[0041] D0-initial diameter of yarn, mm;

[0042] D-diameter of the yarn when subjected to axial tension, mm.

[0043] The specific yarn composition and process parameters are shown in Table 1:

[0044] Table 1

[0045] The prepared elastic filament / staple fiber / inelastic filament three-component spiral auxetic yarn was axially stretched. The diameter change and Poisson's ratio of the yarn under different strains are shown in Table 2, and the tensile deformation diagram is shown in Figure 3:

[0046] Table 2

[0047] As can be seen from Table 2 and Figure 3(a), due to the performance differences between the components, under small tensile strains, the elastic filaments buckle under the combined action of the wrapped staple fibers and the inelastic filaments, and the yarn initially produces a negative Poisson's ratio effect. With further stretching, under ideal conditions, the core filaments and the wrapped components exchange positions, and the yarn exhibits the maximum negative Poisson's ratio effect. In the initial state without stretching, the diameter of the auxetic yarn is 0.496mm. After the auxetic yarn is subjected to specific tensile deformation, the deformation process is mainly divided into four stages: "positive Poisson's ratio - maximum negative Poisson's ratio - maintaining a certain negative Poisson's ratio - positive Poisson's ratio":

[0048] The first stage is shown in Figure 3(b). The inelastic filaments are straightened due to their relatively high modulus, and the core yarn is subjected to force and produces buckling deformation. The staple wrapped yarn still acts on the core yarn, producing a certain wrapping effect. The spirally wrapped tensile yarn exhibits a positive Poisson's ratio. When the strain is 1%, the transverse diameter of the tensile yarn is 0.480 mm, and the Poisson's ratio is a positive number.

[0049] In the second stage, as shown in Figure 3(c), the filament wrapped yarn continues to straighten, and the staple wrapped yarn is stretched from the wrapped surface into the core yarn position under the tensile force. The elastic core yarn is more obviously buckled under stress, and the spirally wrapped tensile yarn shows a negative Poisson's ratio effect. The positions of the wrapping yarn and the core yarn change relative to each other. When the strain is 3%, the transverse diameter of the tensile yarn is 0.531 mm, and the maximum negative Poisson's ratio is -2.36.

[0050] The third stage is shown in Figure 3(d). Under the tensile force, the short fibers are continuously moved from the core surface to the central axis of the yarn. Therefore, they can maintain a certain negative Poisson's ratio under longer tensile deformation. Among them, when the strain reaches 14%, the transverse diameter of the expanded yarn can still reach 0.565 mm, and the negative Poisson's ratio is -0.99.

[0051] In the fourth stage, as shown in Figure 3(e), both the filament wrapped yarn and the staple wrapped yarn are in the core yarn position and are continuously stretched. The lateral change of the yarn is reduced relative to the radial stretching, the overall contour diameter gradually decreases, the bending state of the core yarn is weakened, and the overall negative Poisson's ratio effect is weakened to zero, and even the yarn Poisson's ratio is positive. When the strain is 17%, the lateral diameter of the tensile yarn is 0.493 mm and the negative Poisson's ratio is 0.04.

[0052] Overall, the transverse diameter of the three-component spiral auxetic yarn remains relatively stable under extended tension. Figure 4 shows the Poisson's ratio variation during the stretching process of the three-component spiral auxetic yarn composed of elastic filament, staple fiber, and non-elastic filament. The addition of staple fibers helps the spiral auxetic yarn achieve a minimum negative Poisson's ratio under low tensile stress. Furthermore, the yarn maintains a certain negative Poisson's ratio under extended stress, contributing to the stability of the negative Poisson's ratio in the auxetic yarn's application.

[0053] Example 2-13

[0054] Based on Example 1, the influence of filament drafting multiple and twist coefficient on the negative Poisson's ratio of yarn was explored. The filament drafting multiples were 1.01 to 1.05 and the twist coefficient was 325 to 375. The maximum negative Poisson's ratio of the three-component spiral auxetic yarn of elastic filament / staple fiber / non-elastic filament was compared through experiments. The corresponding maximum negative Poisson's ratio values ​​under different spinning parameters are shown in Table 3:

[0055] Table 3

[0056] As can be seen in Table 3, and by comparing Examples 2, 3, and 4, the negative Poisson's ratio effect of the elastic filament / staple fiber / non-elastic filament three-component spiral auxetic yarn decreases with increasing yarn twist coefficient, with a twist coefficient of 325 being the preferred experimental value. Comparing Examples 2, 5, 6, 7, and 8, it is clear that the elastic filament draft ratio should be as low as possible within the available range. As the draft ratio decreases, the initial stress of the elastic core yarn decreases. When the auxetic yarn is subjected to tension, the core yarn is more easily squeezed and deformed by the wrapping yarn, resulting in a more effective negative Poisson's ratio effect. Furthermore, the lower the elastic filament draft ratio, the higher the control requirements for the filament during spinning. Experimentally, a draft ratio of 1.02 is the preferred elastic filament yarn. By comparing Examples 2, 9, 10, 11, and 12, it can be seen that as the draft ratio of the non-elastic filament increases, the greater the radial extrusion pressure on the elastic filament, the more obvious the negative Poisson's ratio effect of the yarn. However, an excessively large draft ratio will weaken the negative Poisson's ratio effect of the yarn. After experiments, the preferred draft ratio of the non-elastic filament is 1.03. In Example 13, after optimization, a twist coefficient of 325, a draft ratio of 1.03 for the non-elastic filament, and a draft ratio of 1.02 for the elastic filament are selected for spinning. The three-component spiral auxetic yarn of elastic filament / short fiber / non-elastic filament has a good and stable negative Poisson's ratio effect. The addition of cotton staple fibers alleviates the defect of direct wrapping of filaments, which causes the wrapped component to easily slide along the yarn surface, and improves the stability of the yarn structure. At the same time, it gives excellent properties such as a soft feel that cannot be achieved by filaments, expanding the application scenarios of auxetic yarns.

[0057] Example 14

[0058] Based on Example 1 and Example 2, the effect of adjusting the raw materials and fineness on the negative Poisson's ratio of the yarn was explored. 5g / 10m viscose staple fiber, 2.22tex nylon 66 filament and 23.33tex spandex filament were used as raw materials, wherein the viscose staple fiber and nylon 66 filament were used as wrapping components, and the spandex filament was used as the core component. Yarn samples with a fineness of 33.33tex were spun on a modified ring spinning machine. The specific yarn composition and structural parameters and the maximum negative Poisson's ratio are shown in Table 4:

[0059] Table 4

[0060] It can be seen from Table 4 that by changing the raw material components and proportions, the three-component spiral auxetic yarn of elastic filament / short fiber / non-elastic filament has a negative Poisson's ratio effect. It can be seen that the range of selected fibers and filaments used is wide, and the proportion of short fiber components can also be flexibly controlled.

[0061] In summary, the elastic filament / staple fiber / non-elastic filament three-component spiral auxetic yarn of the present invention has good negative Poisson's ratio effect and wearability, broadens the application scenarios of auxetic yarn, and has potential practical application value in wearable protective textiles.

[0062] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A three-component spiral auxetic yarn based on ring spinning, characterized in that: It includes a core yarn, a first wrapping yarn and a second wrapping yarn; the core yarn is an elastic filament, the first wrapping yarn is a short fiber, and the second wrapping yarn is an inelastic filament; the first wrapping yarn is obtained by wrapping the short fiber on the surface of the core yarn, and the second wrapping yarn is obtained by wrapping the inelastic filament on the surface of the core yarn and the first wrapping yarn, and the core yarn, the first wrapping yarn and the second wrapping yarn are formed in one step by a spinning frame.

2. The three-component spiral auxetic yarn based on ring spinning according to claim 1, characterized in that: The elastic filaments are selected from one or more of polyurethane elastic fibers, diene elastic fibers and polyether ester elastic fibers.

3. The three-component spiral auxetic yarn based on ring spinning according to claim 1, characterized in that: The short fibers are selected from one or more of cotton fibers, wool fibers, linen fibers, viscose fibers and polyester fibers.

4. The three-component spiral auxetic yarn based on ring spinning according to claim 1, characterized in that: The non-elastic filaments are selected from one or more of polyester fibers, polyamide fibers, aromatic polyamide fibers and metal wires.

5. The three-component spiral auxetic yarn based on ring spinning according to claim 1, characterized in that: The overall fineness of the elastic filaments in the three-component spiral axial expansion yarn accounts for 70%, the overall fineness of the short fibers accounts for 1%-30%, and the overall fineness of the inelastic filaments accounts for 1%-30%.

6. The three-component spiral auxetic yarn based on ring spinning according to claim 1, characterized in that: The twist coefficient of the three-component spiral auxetic yarn is 300-375.

7. The three-component spiral auxetic yarn based on ring spinning according to claim 1, characterized in that: The twist direction of the three-component spiral auxetic yarn is Z twist or S twist.

8. A method for preparing a three-component spiral auxetic yarn based on ring spinning according to any one of claims 1 to 7, characterized in that: A spinning frame is used as a generating device, including a ring spinning frame, a filament feeding device and a pre-stretching device, wherein the filament feeding device and the pre-stretching device are arranged on the ring spinning frame. The preparation method comprises the following steps: the short fibers and the non-elastic filaments are sequentially wrapped around the elastic filaments through the spinning frame to obtain the three-component spiral tensile yarn based on ring spinning.

9. The method for preparing a three-component spiral auxetic yarn based on ring spinning according to claim 8, characterized in that: During the preparation process, the drafting multiples of the elastic filaments and the non-elastic filaments are independently 1.01-1.

20.

10. The method for preparing a three-component spiral auxetic yarn based on ring spinning according to claim 8, characterized in that: During the preparation process, the drafting multiple of the staple fibers is 15-50 in the front zone and 1.1-1.4 in the back zone.

Images