A temperature-adaptive intelligent variable-thickness interval knitted fabric and its preparation method

Abstract

The present invention belongs to the technical field of knitted fabrics and relates to a temperature-adaptive intelligent variable-thickness spaced knitted fabric and its preparation method. The temperature-adaptive intelligent variable-thickness spaced knitted fabric comprises an upper fabric layer, a lower fabric layer, and spacer yarns connecting the upper and lower fabric layers. Some of the spacer yarns are heat-responsive yarns, while others are non-heat-responsive yarns. The heat-responsive yarns have the property of reversible contraction with temperature changes. The non-heat-responsive yarns have a relative bending stiffness of 1×10 ‑4 ‑6×10 ‑4 cN·cm 2 / tex 2 The ratio of thermally responsive yarn to non-thermally responsive yarn is 1-4:1-2; the density of spacer yarn is 60-250 yarns / cm ‑2 The preparation method includes the steps of using heat-responsive yarn and non-heat-responsive yarn as spacer yarns, and knitting them together with the face yarn through weft knitting or warp knitting to form a spacer knitted fabric. The knitted fabric prepared by the present invention can maintain a stable spacer shape for a long time.

Description

Technical Field

[0001] The present invention belongs to the technical field of knitted fabrics, and relates to a temperature-adaptive intelligent variable-thickness interval knitted fabric and a preparation method thereof. Background Art

[0002] In recent years, with the intensification of global warming and the frequent occurrence of extreme weather events, the demand for temperature-control systems has grown. However, traditional temperature-control systems, such as air conditioning and heating, not only consume large amounts of electricity and energy but also contribute to greenhouse gas emissions, exacerbating the vicious cycle of climate change. In this context, the development of fabrics that can adapt to temperature changes has become an important research direction. These fabrics can intelligently adapt their structure to different environments to maintain wearer comfort over a wider range of temperature fluctuations, effectively reducing indoor energy consumption and outdoor emissions.

[0003] In the research of intelligent temperature-adaptive fabrics, spacer knitted fabrics have attracted considerable attention due to their unique three-dimensional structure. Spacer fabrics use spacer yarns to connect two surface fabric layers, forming a spacer layer of defined thickness. This structure traps a large amount of still air within the spacer layer, endowing the fabric with excellent thermal insulation properties. However, existing intelligent temperature-adaptive spacer fabrics face challenges in maintaining a stable spacer shape.

[0004] For example, patent application CN117552147A discloses a temperature-responsive double-layer binding fabric and its preparation method. Although the temperature responsiveness of the fabric is achieved by using shape memory yarn through weaving technology, in actual applications, due to the softness of the fabric and the lack of sufficient support structure, the elongation of the binding yarn will cause the stability of the spacer layer to decrease, and a stable spacer shape cannot be maintained.

[0005] Therefore, developing a knitted fabric that can achieve temperature adaptive regulation by controlling the changes in the knitted fabric structure when the temperature changes while maintaining a stable interval shape has important practical significance and application prospects. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems existing in the prior art and to provide a temperature-adaptive intelligent variable-thickness interval knitted fabric and a preparation method thereof.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A temperature-adaptive intelligent variable-thickness spacer knitted fabric comprises an upper fabric layer, a lower fabric layer, and spacer yarns connecting the upper and lower fabric layers. Some of the spacer yarns are thermally responsive yarns, while others are non-thermally responsive yarns. If all the spacer yarns were thermally responsive yarns, the elasticity of the thermally responsive yarns would easily cause the upper and lower fabric layers to adhere tightly during weaving, preventing them from maintaining a three-dimensional, spaced-apart configuration at low temperatures.

[0009] The thermoresponsive yarn has the property of shrinking reversibly with temperature changes, so that the distance between the upper and lower fabric layers changes with temperature;

[0010] When the temperature is less than Ta, the length of the thermally responsive yarn is constant at La; when the temperature is greater than Tb, the length of the thermally responsive yarn is constant at Lb; La>Lb; the thermally responsive yarn is a liquid crystal elastomer yarn, Ta is the glass transition temperature, Tb is the phase change transition temperature, when the temperature is greater than or equal to Ta and less than or equal to Tb, the length of the thermally responsive yarn gradually decreases with increasing temperature and gradually increases with decreasing temperature; alternatively, the thermally responsive yarn is a shape memory alloy wire, Ta is the martensite temperature, Tb is the austenite temperature, when the temperature is greater than or equal to Ta and less than or equal to Tb, the length of the thermally responsive yarn is constant at La during heating and constant at Lb during cooling;

[0011] The relative bending stiffness of the non-thermoresponsive yarn is 1×10 -4 -6×10 -4 cN·cm 2 / tex 2 If the relative bending stiffness of the non-thermally responsive yarn is too small, it cannot provide support at low temperatures. If the relative bending stiffness of the non-thermally responsive yarn is too large, the non-thermally responsive yarn cannot bend under the pressure of the thermally responsive yarn's thermal contraction. As a result, the contraction force of the thermally responsive yarn cannot pull the upper and lower fabric layers closer together, which is not conducive to the intelligent thickness change of the knitted fabric.

[0012] The ratio of thermally responsive yarn to non-thermally responsive yarn is 1-4:1-2. On the premise that the non-thermally responsive yarn can provide sufficient support, the more thermally responsive yarn there is, the better the thickness change effect will be. If the number of non-thermally responsive yarn is too large, the bending of the spacer yarn during heating will cause compression thickness, which is not conducive to thickness change.

[0013] The spacing yarn density is 60-250 pcs / cm -2 ; This is because both thermoresponsive and non-thermoresponsive yarns are relatively soft and need to be tightly arranged to provide support.

[0014] As the preferred technical solution:

[0015] In the aforementioned temperature-adaptive intelligent variable-thickness knitted fabric, Tb is set within a range of 30-80°C. When ambient temperatures rise or when the body's surface temperature exceeds 30°C after strenuous exercise, people are prone to experiencing heat discomfort. This invention is intended not only for use as clothing fabrics but also for a wide range of other functional fabric applications. Therefore, the range of Tb is relatively wide.

[0016] As described above, in a temperature-adaptive intelligent variable thickness spaced knitted fabric, when the temperature is less than Ta, the spacing between the upper fabric layer and the lower fabric layer is 3-60 mm; when the temperature is greater than Tb, the spacing between the upper fabric layer and the lower fabric layer is 2.4-45 mm.

[0017] As described above, in a temperature-adaptive intelligent variable thickness interval knitted fabric, when the temperature is less than Ta, the fineness of the thermal response yarn is 20-500D; Lb is 0.3-0.9 times of La.

[0018] As described above, in a temperature-adaptive intelligent variable-thickness spaced knitted fabric, the fineness of the non-thermal-responsive yarn is 20-100D, and the non-thermal-responsive yarn is a chemical fiber yarn (such as polyester multifilament, nylon multifilament, etc.).

[0019] In the temperature-adaptive intelligent variable-thickness spacer knitted fabric as described above, the spacer yarns are arranged in a mono-oblique, cross or upright manner.

[0020] As described above, a temperature-adaptive intelligent variable-thickness spacer knitted fabric, the upper fabric layer and the lower fabric layer are both composed of veils, the fineness of the veils is greater than the spacer yarns, so as to prevent the spacer yarns from being exposed on the fabric surface, and the fineness of the veils is 20-800 dtex; the choice of veils is not limited, as long as it meets the product requirements and machine production requirements, such as polyester filament, nylon filament, etc.

[0021] The present invention also provides a method for preparing a temperature-adaptive intelligent variable thickness spaced knitted fabric as described in any of the above items. Under the condition that the ambient temperature is greater than Tb, heat-responsive yarn and non-heat-responsive yarn are used as spacer yarns, and they are knitted together with the face yarn by weft knitting or warp knitting into a spacer knitted fabric. The elongation of the heat-responsive yarn under the action of machine tension is controlled to be equal to the shrinkage of the heat-responsive yarn when the temperature changes from less than Ta to greater than Tb, thereby obtaining a temperature-adaptive intelligent variable thickness spaced knitted fabric. Among them, controlling the ambient temperature to be greater than Tb can make the heat-responsive yarn in a contracted state, and controlling the elongation of the heat-responsive yarn under the action of machine tension can make the elongation of the heat-responsive yarn at room temperature after being removed from the machine offset the shrinkage of the elongated part affected by the knitting tension during knitting after being removed from the machine, thereby ensuring that the fabric spacing thickness remains stable after the knitted fabric is removed from the machine.

[0022] As the preferred technical solution:

[0023] In the above-mentioned method, the loom used for weft knitting or warp knitting has a gauge of E14 or above, so as to increase the arrangement density of the spacer yarns.

[0024] Beneficial effects:

[0025] When preparing temperature-adaptive intelligent variable-thickness spaced knitted fabrics, the present invention uses thermally responsive yarns with the characteristic of reversible shrinkage with temperature changes and non-thermally responsive yarns with specific relative bending stiffness as spacer yarns. At the same time, during the preparation process, the quantity ratio of thermally responsive yarns to non-thermally responsive yarns and the arrangement density of the spacer yarns are controlled. The resulting temperature-adaptive intelligent variable-thickness spaced knitted fabric can not only achieve temperature adaptive regulation, but also maintain a stable spaced shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram showing the effect of the temperature-adaptive intelligent variable thickness spaced knitted fabric adjusting its thickness according to temperature changes according to Example 1 of the present invention;

[0027] Figure 2 This is the knitting pattern of the temperature-adaptive intelligent variable-thickness spaced knitted fabric according to Example 1 of the present invention. DETAILED DESCRIPTION

[0028] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0029] Example 1

[0030] A method for preparing a temperature-adaptive intelligent variable-thickness interval knitted fabric, the specific steps are as follows:

[0031] (1) Preparation of raw materials;

[0032] Thermally responsive yarn: Liquid crystal elastomer yarn, which has the characteristic of reversible contraction with temperature changes, Ta (glass transition temperature) is 3°C, Tb (phase change transition temperature) is 32°C; when the temperature is less than Ta, the length of the liquid crystal elastomer yarn is constant at La; when the temperature is greater than or equal to Ta and less than or equal to Tb, the length of the liquid crystal elastomer yarn gradually decreases with increasing temperature and gradually increases with decreasing temperature; when the temperature is greater than Tb, the length of the liquid crystal elastomer yarn is constant at Lb; Lb is 0.6 times La; when the temperature is less than Ta, the fineness is 50D;

[0033] Non-thermal responsive yarn: polyester multifilament, specification 45D / 24F, relative bending stiffness 1×10 -4 -3×10 -4 cN·cm 2 / tex 2 ;

[0034] Veil: A mixture of polyester (specification: 70dtex / 72F) and spandex (fineness: 33dtex) with a mass ratio of 2:1;

[0035] (2) Under a 40°C environment, the thermal responsive yarn and the non-thermal responsive yarn were used as spacer yarns and knitted together with the face yarn on a loom with a machine number of E32 to form a spacer knitted fabric. The elongation of the thermal responsive yarn under the action of machine tension was controlled to be 66.67%, and a temperature-adaptive intelligent variable thickness spacer knitted fabric was obtained (the knitting diagram is shown in FIG). Figure 2 wherein the ratio of the number of thermally responsive yarns to the number of non-thermally responsive yarns is 1:1.

[0036] The resulting temperature-adaptive intelligent variable-thickness spacer knitted fabric consists of an upper fabric layer (veil), a lower fabric layer (veil), and spacer yarns connecting the upper and lower fabric layers. The spacer yarns are arranged upright with a density of 250 yarns / cm -2 ;like Figure 1 As shown, when the temperature is less than Ta, the distance between the upper fabric layer and the lower fabric layer is 8 mm; when the temperature is greater than Tb, the distance between the upper fabric layer and the lower fabric layer is 4.8 mm.

[0037] Example 2

[0038] A method for preparing a temperature-adaptive intelligent variable-thickness interval knitted fabric, the specific steps are as follows:

[0039] (1) Preparation of raw materials;

[0040] Thermally responsive yarn: Shape memory alloy wire, which has the characteristic of reversible contraction with temperature changes, Ta (martensite temperature) is 40℃, Tb (austenite temperature) is 80℃; when the temperature is less than Ta, the length of the shape memory alloy wire is constant at La; when the temperature is greater than or equal to Ta and less than or equal to Tb, the length of the shape memory alloy wire is constant at La during heating and constant at Lb during cooling; when the temperature is greater than Tb, the length of the shape memory alloy wire is constant at Lb; Lb is 0.3 times La; when the temperature is less than Ta, the fineness is 500D;

[0041] Non-thermal responsive yarn: nylon multifilament, specification 420D / 64F, relative bending stiffness 4×10 -4 -6×10 -4 cN·cm 2 / tex 2 ;

[0042] Veil: polyester filament, 800dtex;

[0043] (2) Under a 90°C environment, thermally responsive yarn and non-thermally responsive yarn were used as spacer yarns, and a loom with a machine number of E24 was used to knit them together with the face yarn into a spacer knitted fabric. The elongation of the thermally responsive yarn under the action of machine tension was controlled to be 233.33%, thus obtaining a temperature-adaptive intelligent variable thickness spacer knitted fabric; wherein, the ratio of the number of thermally responsive yarns to the number of non-thermally responsive yarns was 1:1.

[0044] The resulting temperature-adaptive intelligent variable-thickness spacer knitted fabric consists of an upper fabric layer (veil), a lower fabric layer (veil), and spacer yarns connecting the upper and lower fabric layers. The spacer yarns are arranged mono-obliquely with a density of 178 yarns / cm. -2 ; When the temperature is less than Ta, the distance between the upper fabric layer and the lower fabric layer is 60mm; when the temperature is greater than Tb, the distance between the upper fabric layer and the lower fabric layer is 18mm.

[0045] Example 3

[0046] A method for preparing a temperature-adaptive intelligent variable-thickness interval knitted fabric, the specific steps are as follows:

[0047] (1) Preparation of raw materials;

[0048] Thermally responsive yarn: Liquid crystal elastomer yarn, which has the characteristic of reversible contraction with temperature changes, Ta (glass transition temperature) is -2°C, Tb (phase change transition temperature) is 30°C; when the temperature is less than Ta, the length of the liquid crystal elastomer yarn is constant at La; when the temperature is greater than or equal to Ta and less than or equal to Tb, the length of the liquid crystal elastomer yarn gradually decreases with increasing temperature and gradually increases with decreasing temperature; when the temperature is greater than Tb, the length of the liquid crystal elastomer yarn is constant at Lb; Lb is 0.8 times La; when the temperature is less than Ta, the fineness is 20D;

[0049] Non-thermal responsive yarn: polyester multifilament, specification 20D / 10F, relative bending stiffness 1×10 -4 -2×10 -4 cN·cm 2 / tex 2 ;

[0050] Veil: A mixture of polyester (50dtex / 72F) and spandex (33dtex) in a mass ratio of 2:1.

[0051] (2) Under a 40°C environment, thermally responsive yarn and non-thermally responsive yarn were used as spacer yarns, and a loom with a machine number of E24 was used to knit them together with the face yarn to form a spacer knitted fabric. The elongation of the thermally responsive yarn under the action of machine tension was controlled to 25%, thereby obtaining a temperature-adaptive intelligent variable thickness spacer knitted fabric; wherein, the ratio of the thermally responsive yarn to the non-thermally responsive yarn was 4:1.

[0052] The resulting temperature-adaptive intelligent variable-thickness spacer knitted fabric consists of an upper fabric layer (veil), a lower fabric layer (veil), and spacer yarns connecting the upper and lower fabric layers. The spacer yarns are arranged upright with a density of 165 yarns / cm -2 ; When the temperature is less than Ta, the distance between the upper fabric layer and the lower fabric layer is 3mm; when the temperature is greater than Tb, the distance between the upper fabric layer and the lower fabric layer is 2.4mm.

[0053] Example 4

[0054] A method for preparing a temperature-adaptive intelligent variable-thickness interval knitted fabric, the specific steps are as follows:

[0055] (1) Preparation of raw materials;

[0056] Thermally responsive yarn: Liquid crystal elastomer yarn, which has the characteristic of reversible contraction with temperature changes, Ta (glass transition temperature) is 3°C, Tb (phase change transition temperature) is 50°C; when the temperature is less than Ta, the length of the liquid crystal elastomer yarn is constant at La; when the temperature is greater than or equal to Ta and less than or equal to Tb, the length of the liquid crystal elastomer yarn gradually decreases with increasing temperature and gradually increases with decreasing temperature; when the temperature is greater than Tb, the length of the liquid crystal elastomer yarn is constant at Lb; Lb is 0.9 times La; when the temperature is less than Ta, the fineness is 200D;

[0057] Non-thermal responsive yarn: nylon multifilament, specification 210D / 32F, relative bending stiffness 3×10 -4 -5×10 -4 cN·cm 2 / tex 2 ;

[0058] Veil: polyester filament, 500dtex;

[0059] (2) Under an environment of 80°C, thermally responsive yarn and non-thermally responsive yarn were used as spacer yarns, and a loom with a machine number of E20 was used to knit them together with the face yarn into a spacer knitted fabric. The elongation of the thermally responsive yarn under the action of machine tension was controlled to be 11.11%, thereby obtaining a temperature-adaptive intelligent variable thickness spacer knitted fabric; wherein, the ratio of the number of thermally responsive yarns to the number of non-thermally responsive yarns was 2:1.

[0060] The resulting temperature-adaptive intelligent variable-thickness spacer knitted fabric consists of an upper fabric layer (veil), a lower fabric layer (veil), and spacer yarns connecting the upper and lower fabric layers. The spacer yarns are arranged crosswise with a density of 150 yarns / cm -2 ; When the temperature is less than Ta, the distance between the upper fabric layer and the lower fabric layer is 50mm; when the temperature is greater than Tb, the distance between the upper fabric layer and the lower fabric layer is 45mm.

[0061] Example 5

[0062] A method for preparing a temperature-adaptive intelligent variable-thickness interval knitted fabric, the specific steps are as follows:

[0063] (1) Preparation of raw materials;

[0064] Thermally responsive yarn: Shape memory alloy wire, which has the characteristic of reversible contraction with temperature changes, Ta (martensite temperature) is 34°C, Tb (austenite temperature) is 58°C; when the temperature is less than Ta, the length of the shape memory alloy wire is constant at La; when the temperature is greater than or equal to Ta and less than or equal to Tb, the length of the shape memory alloy wire is constant at La during heating, and the length of the shape memory alloy wire is constant at Lb during cooling; when the temperature is greater than Tb, the length of the shape memory alloy wire is constant at Lb; Lb is 0.6 times La; when the temperature is less than Ta, the fineness is 300D;

[0065] Non-thermal responsive yarn: polyester multifilament, specification 210D / 32F, relative bending stiffness 1×10 -4 -3×10 -4 cN·cm 2 / tex 2 ;

[0066] Veil: nylon filament, fineness is 300dtex;

[0067] (2) Under an environment of 60°C, thermally responsive yarn and non-thermally responsive yarn were used as spacer yarns, and a loom with a machine number of E14 was used to knit them together with the face yarn to form a spacer knitted fabric. The elongation of the thermally responsive yarn under the action of machine tension was controlled to be 66.67%, thus obtaining a temperature-adaptive intelligent variable thickness spacer knitted fabric; wherein, the ratio of the number of thermally responsive yarns to the number of non-thermally responsive yarns was 3:2.

[0068] The resulting temperature-adaptive intelligent variable-thickness spacer knitted fabric consists of an upper fabric layer (veil), a lower fabric layer (veil), and spacer yarns connecting the upper and lower fabric layers; the spacer yarns are arranged upright with a density of 60 yarns / cm -2 ; When the temperature is less than Ta, the distance between the upper fabric layer and the lower fabric layer is 10mm; when the temperature is greater than Tb, the distance between the upper fabric layer and the lower fabric layer is 6mm.

Claims

1. A temperature-adaptive intelligent variable thickness spacer knitted fabric, comprising an upper fabric layer, a lower fabric layer, and spacer yarns connecting the upper fabric layer and the lower fabric layer, characterized in that: A portion of the spacer yarns is a thermally responsive yarn, and another portion of the spacer yarns is a non-thermally responsive yarn; The thermoresponsive yarn has the property of reversibly shrinking with temperature changes, so that the distance between the upper and lower fabric layers changes with temperature; When the temperature is less than Ta, the length of the thermally responsive yarn is constant at La; When the temperature is greater than Tb, the length of the thermally responsive yarn is constant at Lb; La>Lb; the thermally responsive yarn is a liquid crystal elastomer yarn, Ta is the glass transition temperature, Tb is the phase change transition temperature, or the thermally responsive yarn is a shape memory alloy wire, Ta is the martensite temperature, Tb is the austenite temperature; The relative bending stiffness of the non-thermoresponsive yarn is 1×10 -4 -6×10 -4 cN·cm 2 / tex 2 ; The ratio of the number of thermoresponsive yarns to the number of non-thermoresponsive yarns is 1-4:1-2; The spacing yarn density is 60-250 pcs / cm -2 .

2. The temperature-adaptive intelligent variable thickness spacer knitted fabric according to claim 1, characterized in that: The value range of Tb is 30-80℃.

3. The temperature-adaptive intelligent variable thickness spacer knitted fabric according to claim 1, characterized in that: When the temperature is lower than Ta, the distance between the upper fabric layer and the lower fabric layer is 3-60 mm; when the temperature is higher than Tb, the distance between the upper fabric layer and the lower fabric layer is 2.4-45 mm.

4. The temperature-adaptive intelligent variable thickness spaced knitted fabric according to claim 3, characterized in that: When the temperature is lower than Ta, the fineness of the thermally responsive yarn is 20-500D; Lb is 0.3-0.9 times of La.

5. The temperature-adaptive intelligent variable thickness spaced knitted fabric according to claim 2, characterized in that: The fineness of the non-thermal responsive yarn is 20-100D, and the non-thermal responsive yarn is chemical fiber.

6. The temperature-adaptive intelligent variable thickness spaced knitted fabric according to claim 2, characterized in that: The spacer yarns are arranged in mono-oblique, cross or upright patterns.

7. The temperature-adaptive intelligent variable thickness spaced knitted fabric according to claim 2, characterized in that: The upper fabric layer and the lower fabric layer are both composed of face veils. The fineness of the face veils is greater than that of the spacer yarns, and the fineness of the face veils is 20-800 dtex.

8. A method for preparing a temperature-adaptive intelligent variable thickness spaced knitted fabric according to any one of claims 2 to 7, characterized in that: Under the condition that the ambient temperature is greater than Tb, thermally responsive yarn and non-thermally responsive yarn are used as spacer yarns, which are knitted together with the face yarn by weft knitting or warp knitting to form a spacer knitted fabric. The elongation of the thermally responsive yarn under the action of machine tension is controlled to be equal to the contraction of the thermally responsive yarn when the temperature changes from less than Ta to greater than Tb, thus obtaining a temperature-adaptive intelligent variable-thickness spacer knitted fabric.

9. The method according to claim 8, characterized in that The loom used for weft knitting or warp knitting is E14 or above.

Images