A braided composite structure negative poisson's ratio fabric and a method of making the same

Abstract

The application discloses a kind of chain compound structure negative poisson ratio fabric and its preparation method, the fabric includes loop portion and non-loop portion, wherein loop portion is with certain strength chemical fiber filament, non-loop portion is composed of negative poisson ratio yarn, negative poisson ratio yarn is arranged in parallel along transverse direction, chemical fiber filament is looped in longitudinal direction according to chain weave structure, and the series connection of parallel arranged negative poisson ratio yarn is fixed.Under the action of transverse stretching, negative poisson ratio yarn produces bending deformation, and profile diameter increases, so that the overall significant negative poisson ratio effect of fabric is realized, and the negative poisson ratio effect of fabric is close to the effect of single negative poisson ratio yarn.The fabric structure is widely applicable to raw material range, and the forming process is simple, wherein the non-loop portion of negative poisson ratio yarn is driven into the working width range of warp knitting machine by single-head or multi-head weft insertion system, and is in a completely flat state in the fabric, and the chemical fiber filament is looped in longitudinal direction to realize weaving.

Description

Technical Field

[0001] This invention belongs to the field of textile processing technology and relates to a braided composite structure negative Poisson's ratio fabric and its preparation method. Background Technology

[0002] Negative Poisson's ratio materials are man-made structures with a negative Poisson's ratio. Unlike conventional materials, negative Poisson's ratio materials contract in the direction perpendicular to the force under axial compression and expand in the direction perpendicular to the force under axial tension. This anomalous mechanical property gives the structure higher impact resistance, shear resistance, and energy absorption performance. Due to their high internal porosity, negative Poisson's ratio structural materials deform rapidly under heavy loads, resulting in limited load-bearing capacity. In the textile industry, negative Poisson's ratio fabrics include woven and knitted fabrics. Existing technologies regarding negative Poisson's ratio fabrics and their preparation methods are as follows:

[0003] A method for preparing a warp-knitted spacer fabric with a negative Poisson's ratio effect (application number: CN201610629345.2) involves first weaving a single-sided hexagonal mesh based on a variable warp flat and chain braiding structure on a warp knitting machine, and then connecting it with a chain braiding structure using monofilaments with high stiffness. The resulting finished product can automatically produce skew deformation after being relaxed off the machine, thus exhibiting a negative Poisson's ratio effect.

[0004] An explosion-resistant composite fabric with good coverage (application number: CN202210574396.5) includes a surface layer, a core layer and an inner layer. The negative Poisson's ratio fabrics in the surface layer and the inner layer are made by cross-weaving core-spun yarn and filament to form a sawtooth structure to achieve a negative Poisson's ratio effect.

[0005] A negative Poisson's ratio woven fabric (application number: CN201720277447.2) consists of an outer layer and an inner layer. The outer layer is made of high-elasticity nylon yarn, and the inner layer is made of high-modulus polyester yarn. The outer layer, the inner layer, and the bonding structure of the two layers are all plain weave.

[0006] A negative Poisson's ratio two-dimensional warp-knitted fabric and its weaving method (application number: CN201510392498.5) includes a ground structure part and a textured part. The base fabric is a warp-knitted hexagonal mesh fabric. An additional front comb weave exerts a planar force on the base fabric, causing the base fabric structure to lose its balance and tilt to the left and right, thereby forming a warp-knitted structure with a negative Poisson's ratio effect, and obtaining a negative Poisson's ratio two-dimensional warp-knitted fabric.

[0007] Looking at the above negative Poisson's ratio fabrics, it is clear that the current negative Poisson's ratio fabrics have a simple structure. After the negative Poisson's ratio yarn is formed into a fabric, its negative Poisson's ratio effect is greatly reduced, resulting in an insignificant negative Poisson's ratio effect in the overall fabric, which restricts its application in various fields. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a braided composite structure negative Poisson's ratio fabric and its preparation method.

[0009] The technical solution of this invention is as follows:

[0010] One aspect of the present invention provides a braided composite structure negative Poisson's ratio fabric, the fabric comprising a looped portion and a non-looped portion, the non-looped portion being composed of negative Poisson's ratio yarns arranged in parallel in the transverse direction, and the looped portion being a braided structure used to fix the non-looped portion.

[0011] Furthermore, the looped portion is made of chemical fiber filaments, which are longitudinally looped according to a chain weave structure to connect and fix parallel negative Poisson's ratio yarns.

[0012] Furthermore, the coiled portion is either an open coil or a closed coil.

[0013] Furthermore, the looped portion does not affect the axial tensile deformation of the negative Poisson's ratio yarn.

[0014] Furthermore, under the action of transverse stretching, the negative Poisson's ratio yarn undergoes bending deformation from a straight state, and the outline diameter increases, thereby achieving a significant negative Poisson's ratio effect for the entire fabric.

[0015] Furthermore, factors affecting the negative Poisson's ratio effect of fabrics include the maximum Poisson's ratio value of the negative Poisson's ratio yarn, the arrangement of the negative Poisson's ratio yarn, and the arrangement density of the negative Poisson's ratio yarn.

[0016] Furthermore, under lateral stretching, the fabric's pores dynamically change, resulting in a variety of pattern effects.

[0017] Another aspect of the present invention provides a method for preparing the above-described braided composite structure negative Poisson's ratio fabric, wherein the non-loop portion of the negative Poisson's ratio yarn is inserted into the working width range of the warp knitting machine and is in a completely straight state in the fabric, and the chemical fiber filaments are woven into loops along the longitudinal direction to achieve weaving.

[0018] Furthermore, the negative Poisson's ratio yarn is inserted into the warp knitting machine via a single-head or multi-head weft insertion system.

[0019] The beneficial effects of this invention are as follows: Under transverse stretching, the negative Poisson's ratio yarn undergoes bending deformation, increasing its profile diameter, thereby achieving a significant negative Poisson's ratio effect across the entire fabric—that is, the negative Poisson's ratio effect of the fabric is close to or greater than the effect of a single negative Poisson's ratio yarn. Simultaneously, with the stretching and deformation of the negative Poisson's ratio yarn and the fabric, the fabric's porosity dynamically changes, resulting in a variety of pattern effects. This fabric structure is applicable to a wide range of raw materials and has a simple forming process. Attached Figure Description

[0020] Figure 1 Structural diagram of a chain-linked composite structure fabric with negative Poisson's ratio;

[0021] Figure 2 Poisson's ratio curves for negative Poisson's ratio yarns and their braided composite structures. Detailed Implementation

[0022] like Figure 1 As shown in this embodiment, a chain-knitted negative Poisson's ratio fabric is presented. The fabric includes a looped portion 1 and a non-looped portion 2. The looped portion is composed of polyester filaments, and the non-looped portion is composed of nylon filaments wrapped with spandex to form a negative Poisson's ratio yarn. The fabric structure has good stability. The negative Poisson's ratio yarn in the non-looped portion is inserted into the working width of the warp knitting machine by a single-head weft insertion system, and remains completely straight in the fabric. The polyester filaments are woven into loops along the longitudinal direction to achieve weaving.

[0023] In this embodiment, the negative Poisson's ratio yarn is arranged in parallel in the transverse direction, and the chemical fiber filaments are formed into loops in the longitudinal direction according to the braided structure, thereby connecting and fixing the parallel negative Poisson's ratio yarn in series.

[0024] When the polyester filaments are longitudinally looped according to the chain weave structure, they can be either open or closed loops without affecting the axial tensile deformation of the negative Poisson's ratio yarn. Under transverse tension, the negative Poisson's ratio yarn undergoes bending deformation, increasing its profile diameter, thereby achieving a significant negative Poisson's ratio effect across the entire fabric. In this embodiment, factors affecting the negative Poisson's ratio effect of the fabric include the maximum Poisson's ratio value of the negative Poisson's ratio yarn, the arrangement of the negative Poisson's ratio yarn, and the arrangement density of the negative Poisson's ratio yarn. The Poisson's ratio test results are as follows: Figure 2 As shown, the negative Poisson's ratio yarn and its fabric have the most significant negative Poisson's ratio effect when the axial elongation is 10%, with values ​​of -3.21 and -3.11, respectively. It can be seen that the weaving structure of this embodiment does not significantly reduce the negative Poisson's ratio of the negative Poisson's ratio yarn, and is basically close to or even exceeds the negative Poisson's ratio of the yarn.

[0025] In summary, the braided composite structure negative Poisson's ratio fabric disclosed in this invention can effectively maximize the tensile deformation of negative Poisson's ratio yarn, making the negative Poisson's ratio effect of the fabric close to that of a single negative Poisson's ratio yarn, and the preparation method is simple and easy to operate.

[0026] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A braided composite structure negative Poisson's ratio fabric, characterized in that: The fabric comprises a looped portion and a non-looped portion. The non-looped portion is composed of negative Poisson's ratio yarns arranged in parallel laterally. The looped portion has a chain knitting structure used to fix the non-looped portion. The looping part is made of chemical fiber filaments, which are formed longitudinally according to the braided chain structure, and the parallel negative Poisson's ratio yarns are connected and fixed in series. The coiled portion is either an open coil or a closed coil.

2. The braided composite structure negative Poisson's ratio fabric according to claim 1, characterized in that: The looped portion does not affect the axial tensile deformation of the negative Poisson's ratio yarn.

3. A braided composite structure negative Poisson's ratio fabric according to claim 1 or 2, characterized in that: Under lateral stretching, the negative Poisson's ratio yarn undergoes bending deformation from a straight state, increasing its profile diameter, thereby achieving a significant negative Poisson's ratio effect for the entire fabric.

4. The braided composite structure negative Poisson's ratio fabric according to claim 3, characterized in that: Factors affecting the negative Poisson's ratio effect of fabrics include the maximum Poisson's ratio value of the negative Poisson's ratio yarn, the arrangement of the negative Poisson's ratio yarn, and the arrangement density of the negative Poisson's ratio yarn.

5. The braided composite structure negative Poisson's ratio fabric according to claim 3, characterized in that: Under lateral stretching, the pores of the fabric change dynamically, resulting in a variety of pattern effects.

6. A method for preparing a braided composite structure negative Poisson's ratio fabric according to any one of claims 1 to 5, characterized in that: The non-loop portion of the negative Poisson's ratio yarn is inserted into the working width range of the warp knitting machine and is in a completely straight state in the fabric. The chemical fiber filaments are woven into loops along the longitudinal direction to achieve weaving.

7. The method according to claim 6, characterized in that: The negative Poisson's ratio yarn is inserted into the warp knitting machine via a single-head or multi-head weft insertion system.

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