Flame-retardant and high-strength covering yarn and textile

Abstract

The invention belongs to the technical field of textiles, and discloses a flame-retardant and high-strength covering yarn and a textile. The covering yarn comprises a core yarn and wrapping fibers arranged on the surface of the core yarn, the core yarn comprises flame-retardant polyester fibers, and the core yarn accounts for 15%-35% of the mass of the covering yarn; the breaking strength of the core yarn is larger than or equal to 4.0 cN / dtex, the wrapping fiber comprises high-temperature carbonized expansion fiber, and the high-temperature carbonized expansion fiber comprises one or more of polyisophthaloyl metaphenylene diamine fiber, polysulfonamide and flame-retardant acrylic fiber. A core-spun structure is adopted, the flame-retardant polyester fiber serves as the core yarn, the high-temperature carbonized expansion fiber with intrinsic flame retardance serves as the wrapping fiber, the flame-retardant polyester fiber is not exposed on the outer layer of the yarn, the wrapping fiber protects the flame-retardant polyester fiber on the inner layer, and therefore the problems that the flame-retardant polyester fiber melts and drops, and high-temperature secondary scalding is likely to be caused are solved; meanwhile, the covering yarn has good breaking strength and breaking elongation.

Description

Technical Field

[0001] The present invention belongs to the technical field of textiles, and particularly relates to a core-spun yarn and textile with flame retardancy and high strength. Background Art

[0002] Traditional blended flame-retardant yarns have low strength, and it is difficult to improve the tensile breaking strength and tearing strength of textiles such as fabrics and garments prepared therefrom.

[0003] Flame-retardant polyester fibers have the characteristics of high strength and good flame-retardant performance. Therefore, there has been research on blending flame-retardant polyester fibers with other inherently flame-retardant yarns to prepare yarns and improve strength. However, under the action of a fire source, the flame-retardant polyester fibers first soften and then melt and shrink to form droplets, which can easily cause high-temperature burns. Traditional technologies mainly make polyester fibers have flame-retardant properties by adding flame retardants, copolymerization or blending techniques, and coating flame-retardant coatings on the surface of polyester fibers during spinning production, but the melting problem still occurs. Even when using flame-retardant polyester fibers and other inherently flame-retardant non-melting-drop fibers to prepare blended yarns, the problem of melting and dripping of the flame-retardant polyester fibers still cannot be solved, seriously restricting their application in the fields of fire protection, emergency rescue, flight suits, aerospace, etc.

[0004] Therefore, there is an urgent need to develop a product with good flame-retardant effect and high strength. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. For this purpose, the present invention provides a core-spun yarn and textile with flame retardancy and high strength. The core-spun yarn of the present invention has excellent high-temperature resistance, heat insulation, and flame-retardant properties, and at the same time has good breaking strength and elongation at break.

[0006] In the first aspect of the present invention, a core-spun yarn is provided. The core-spun yarn includes a core yarn and an outer wrapping fiber provided on the surface of the core yarn. The core yarn includes flame-retardant polyester fibers, and the core yarn accounts for 15%-35% of the mass of the core-spun yarn; the breaking strength of the core yarn is ≥4.0 cN / dtex, and the outer wrapping fiber includes high-temperature carbonized and expanded fibers, and the high-temperature carbonized and expanded fibers include one or more of poly(m-phenylene isophthalamide) fibers, polysulfonated aramid fibers, and flame-retardant acrylic fibers.

[0007] Specifically, by limiting the mass ratio of the core yarn in the core-spun yarn, the core-spun yarn can have relatively excellent breaking strength and elongation at break. At the same time, the flame-retardant polyester fibers in the core yarn can be fully wrapped by the outer wrapping fiber, and the situation of the core yarn being exposed will not occur, effectively solving the situation that the molten droplets generated by the flame-retardant polyester fibers at high temperature cause high-temperature burns to the human body.

[0008] When the mass percentage of the core yarn in the core-spun yarn is < 15%, the proportion of the flame-retardant polyester fiber in the core yarn is relatively small, and the improvement of the breaking strength and elongation at break of the overall core-spun yarn is relatively low. Moreover, the yarn count of the flame-retardant polyester fiber core yarn to be prepared is relatively high, and the spinning difficulty is large, which easily leads to unstable product quality and relatively high production costs.

[0009] When the mass percentage of the core yarn in the core-spun yarn is > 35%, the core yarn is relatively thick and difficult to be fully covered by the outer wrapping fiber, resulting in the exposure of the core yarn. At high temperatures, molten droplets will appear and cause high-temperature burns to the human body.

[0010] Specifically, using a flame-retardant polyester fiber with a breaking strength ≥ 4.0 cN / dtex as the core yarn in the present invention can ensure that the overall core-spun yarn has excellent breaking strength.

[0011] Specifically, the poly(m-phenylene isophthalamide) fiber, polysulfone amide fiber, and flame-retardant acrylic fiber in the present invention are all inherently flame-retardant fibers with the chemical property of carbonization and expansion. These fibers will carbonize and expand under high-temperature action to form a dense carbon layer. On the basis of fully exerting the flame-retardant performance, the carbon layer generated after carbonization will further strengthen the protection of the outer wrapping fiber on the inner core flame-retardant polyester fiber, more effectively avoiding the situation of high-temperature burns caused by the high-temperature molten droplets of the flame-retardant polyester fiber to the human body.

[0012] The present invention mainly uses the core yarn to further improve the strength of the flame-retardant yarn. To achieve this goal, the breaking strength of the core yarn should be greater than that of the outer wrapping fiber. The outer wrapping fiber mainly uses one or several of poly(m-phenylene isophthalamide) fiber, polysulfone amide fiber, and flame-retardant acrylic fiber. The yarn made of these fibers will have a maximum breaking strength of 3.5 cN / dtex. Using a flame-retardant polyester fiber with a breaking strength ≥ 4.0 cN / dtex as the core yarn can ensure that the overall core-spun yarn has excellent breaking strength.

[0013] In some embodiments of the present invention, the flame-retardant polyester fiber uses filament fiber.

[0014] Specifically, the filament polyester fiber has more excellent breaking strength, more stable fiber properties, and better processing properties. The filament fiber has continuous length, and the molecular chains are tightly combined, having higher breaking strength. At the same time, the filament fiber has better uniformity, its fiber structure is consistent, and its fiber properties are more stable, without the problem of strength fluctuation caused by different fiber lengths of staple fibers. Secondly, the filament fiber has fewer weak loops, and during the production process, the breaking risk of the fiber is lower, and the production continuity is better.

[0015] In some embodiments of the present invention, the mass percentage of the core yarn in the core-spun yarn is 18% - 25%.

[0016] Specifically, within the mass percentage range of the core yarn of this core-spun yarn, the core yarn is of moderate thickness, and the processing difficulty of spinning the core yarn is relatively low. At the same time, the prepared flame-retardant polyester fiber core yarn has a certain breaking strength, and it is not easy to break during the spinning of the overall core-spun yarn, with strong production continuity and excellent quality of the spun core-spun yarn.

[0017] In some embodiments of the present invention, the outer fiber further includes one or several of polyimide, poly(arylene oxadiazole) fiber, poly(p-phenyleneterephthalamide) fiber, and antistatic fiber.

[0018] Specifically, by adding polyimide and poly(arylene oxadiazole) fiber, the high-temperature resistance of the overall yarn can be better improved, ensuring that the fabric prepared therefrom is not easily damaged and has a better protective effect. The outer fiber contains high-temperature carbonized and expanded fiber, and such fibers will undergo carbonization and expansion under high-temperature action, which will cause the fabric prepared to be easily damaged and have a lower protective effect. By adding the above-mentioned fibers with more excellent high-temperature resistance, the high-temperature resistance of the overall core-spun yarn can be enhanced, which is beneficial to improving the problem of fabric damage after carbonization of the high-temperature carbonized and expanded fiber.

[0019] In some embodiments of the present invention, the outer fiber includes poly(m-phenyleneterephthalamide) fiber and poly(arylene oxadiazole) fiber; the mass percentage of the poly(m-phenyleneterephthalamide) fiber in the outer fiber is 40%-80%, and the mass percentage of the poly(arylene oxadiazole) fiber in the outer fiber is 20%-60%.

[0020] Specifically, under the action of high temperature, the poly(m-phenyleneterephthalamide) fiber undergoes carbonization and expansion, improving the protective effect of the outer fiber on the inner core yarn of flame-retardant polyester fiber. The presence of the poly(arylene oxadiazole) fiber further improves the high-temperature resistance of the yarn, making the overall core-spun yarn not easily damaged at high temperature and the core yarn not exposed.

[0021] The poly(m-phenyleneterephthalamide) fiber will undergo carbonization and expansion under high-temperature action to form a dense carbon layer, enabling the outer fiber to have a protective effect on the inner core yarn of flame-retardant polyester fiber, effectively avoiding the situation of high-temperature melting droplets of the flame-retardant polyester fiber and causing high-temperature burns to the human body.

[0022] The poly(arylene oxadiazole) fiber has excellent high-temperature resistance, and its thermal decomposition temperature is as high as 530°C and can be applied to the working condition of 250°C for a long time. By adding the poly(arylene oxadiazole) fiber, the high-temperature resistance of the overall core-spun yarn can be further improved, ensuring that the inner core-spun structure of the core-spun yarn can stably exist in a high-temperature environment, and the overall outer fiber will not rupture, effectively solving the problem that the inner core yarn of flame-retardant polyester fiber is exposed and generates melting droplets due to the rupture of the outer fiber at high temperature, causing high-temperature burns to the human body.

[0023] When the content of poly - m - phenylene isophthalamide fiber is within the range of 40% - 80%, it can ensure that the outer - wrapped fiber forms a continuous and dense carbon layer under high - temperature action, exerting excellent heat - insulation effect. At the same time, it can ensure that the inner - layer flame - retardant polyester fiber is not exposed, and there will be no molten droplets generated under high - temperature action to cause secondary scalding to the human body. When the content of polyarylene oxadiazole fiber is within the range of 20% - 60%, it can fully improve the overall high - temperature resistance performance of the core - spun yarn, and effectively improve the problem of fabric breakage after the carbonization of the high - temperature carbonized and expanded fiber, significantly enhancing the high - temperature dimensional stability of the fabric and ensuring that the fabric does not break.

[0024] In some embodiments of the present invention, the outer - wrapped fiber includes poly - m - phenylene isophthalamide fiber, polyarylene oxadiazole fiber, and flame - retardant acrylic fiber. The mass percentage of the poly - m - phenylene isophthalamide fiber in the outer - wrapped fiber is 30% - 50%, the mass percentage of the polyarylene oxadiazole fiber in the outer - wrapped fiber is 20% - 40%, and the mass percentage of the flame - retardant acrylic fiber in the outer - wrapped fiber is 25% - 45%.

[0025] Specifically, by adding the flame - retardant acrylic fiber in the present invention, the yarn can have a higher thermal protection coefficient, that is, higher heat - insulation performance. The flame - retardant acrylic fiber has the chemical property of high - temperature carbonization and expansion, and the dense carbon layer formed after carbonization has excellent heat - insulation effect. Through its combined action with the poly - m - phenylene isophthalamide fiber and the polyarylene oxadiazole fiber, the thermal protection coefficient of the overall core - spun yarn can be significantly improved.

[0026] In some embodiments of the present invention, the outer - wrapped fiber further includes polyarylene oxadiazole fiber and antistatic fiber. The mass percentage of the antistatic fiber in the outer - wrapped fiber is 2% - 8%, and the mass percentage of the polyarylene oxadiazole fiber in the outer - wrapped fiber ≥20%.

[0027] Specifically, by adding the antistatic fiber in the present invention, the spinnability of the overall core - spun yarn is improved. At the same time, the mass percentage of the polyarylene oxadiazole fiber ≥20% ensures that the fabric prepared from the core - spun yarn does not break at high temperature. Since the outer - wrapped fiber is basically an inherently flame - retardant fiber, the antistatic performance of this kind of inherently flame - retardant fiber is poor, and the fiber is easily adsorbed by the machine during the spinning process, resulting in problems such as more hairiness of the prepared core - spun yarn and poor yarn quality. By adding the antistatic fiber, the spinnability of the outer - wrapped fiber can be improved, and the yarn quality of the spun yarn can be enhanced. At the same time, the mass percentage of the polyarylene oxadiazole fiber ≥20% can ensure that the prepared core - spun yarn has excellent high - temperature resistance performance, and the fabric prepared therefrom will not break.

[0028] In some embodiments of the present invention, the breaking elongation rate of the core - spun yarn is 70% - 110% of the breaking elongation rate of the core yarn.

[0029] Specifically, the present invention defines that the breaking elongation of the core-spun yarn is within the above range, which can fully exert the excellent strength performance of the inner layer of flame-retardant polyester fiber, and the core yarn will not break earlier than the outer wrapping fiber during stretching, so that the overall yarn has excellent breaking strength.

[0030] When the breaking elongation of the core-spun yarn < 70% of the breaking elongation of the flame-retardant polyester fiber (core yarn), it will limit the full exertion of the strength performance of the flame-retardant polyester fiber, resulting in a relatively low overall strength of the core-spun yarn and making it difficult to meet the requirements of complex working environments.

[0031] When the breaking elongation of the core-spun yarn > 110% of the breaking elongation of the flame-retardant polyester fiber (core yarn), during the stretching process of the overall core-spun yarn, the flame-retardant polyester fiber of the core yarn will break earlier than the outer wrapping fiber, unable to achieve uniform stress on the inner and outer layer fibers of the core-spun yarn, resulting in a relatively low overall strength of the core-spun yarn.

[0032] In some embodiments of the present invention, for some fibers in the outer wrapping fiber, their breaking elongation is 1 - 1.8 times that of the core yarn, and the mass ratio of this part of the fibers in the outer wrapping fiber ≥ 65%.

[0033] Specifically, through the above technical solution, the problem that the fiber skewing caused by twisting restricts the strength performance of the outer wrapping fiber can be effectively solved, making the breaking elongation of the outer wrapping fiber greater than that of the inner layer core flame-retardant polyester fiber, achieving the effect that the outer wrapping fiber and the inner layer core flame-retardant polyester fiber can be uniformly stressed and break simultaneously during stretching, and greatly improving the overall strength performance of the core-spun yarn.

[0034] During the twisting process of the outer wrapping fiber, fiber skewing will occur, making it difficult for the outer wrapping fiber to fully exert its own strength performance. When the mass ratio of this part of the fibers in the outer wrapping fiber < 65%, the overall breaking elongation of the outer wrapping fiber will be lower than that of the inner layer core flame-retardant polyester fiber. When the prepared core-spun yarn is stretched, it is difficult for the outer wrapping fiber and the inner layer flame-retardant polyester fiber to be uniformly stressed, and the situation where the outer wrapping fiber breaks earlier than the inner layer core flame-retardant polyester fiber occurs, resulting in the problem of low overall strength of the core-spun yarn.

[0035] In some embodiments of the present invention, the core-spun yarn is prepared by compact spinning or vortex spinning.

[0036] Specifically, the present invention uses the compact spinning or vortex spinning process to spin the core-spun yarn, which can improve the yarn compactness, further strengthen the protection of the inner layer core flame-retardant polyester fiber by the outer wrapping fiber, avoid the situation of high-temperature scalding of the human body caused by the molten droplets of the inner layer flame-retardant polyester fiber at high temperatures, and at the same time can significantly improve the hairiness of the core-spun yarn and enhance the wear resistance of the core-spun yarn.

[0037] The compact spinning process uses negative pressure airflow to tightly hold the fibers together before twisting, and the fiber head is twisted into the yarn, which improves the compactness of the yarn. At the same time, thanks to the negative pressure, the twisting triangle area is basically eliminated, which greatly reduces the hairiness of the yarn. The vortex spinning process twists the fibers through high-speed rotating vortices. This twisting method can force the fiber head end to be rolled into the yarn core and the tail end to be wrapped in the outer layer, which greatly improves the compactness of the yarn and significantly reduces the hairiness of the yarn.

[0038] A second aspect of the present invention provides a textile, comprising the core-spun yarn according to the first aspect of the present invention.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] (1) The core-spun yarn provided by the present invention adopts a core-spun structure, with flame-retardant polyester fiber as the core yarn and high-temperature carbonized expandable fiber that is inherently flame-retardant as the outer fiber, so that the flame-retardant polyester fiber is not exposed on the outer layer of the yarn, and the outer fiber protects the inner layer of the flame-retardant polyester fiber, thereby solving the problem of secondary burns caused by high-temperature molten droplets of the flame-retardant polyester fiber; at the same time, the flame-retardant polyester fiber has the characteristic of high strength, and when it is used as the core yarn, the overall core-spun yarn has good breaking strength and breaking elongation, and under extremely harsh conditions, the flame-retardant polyester fiber shrinks when it encounters high temperature. With the help of the shrinkage phenomenon, the core-spun yarn shrinks, the overall adhesion is tighter, and the thermal insulation and protection performance is improved.

[0041] (2) The core-spun yarn provided by the present invention has excellent high temperature resistance, heat insulation and flame retardancy, and also has excellent breaking strength and breaking elongation, wherein the limiting oxygen index is 30.8-34.6%, the breaking strength is 24.2-34.2 cN / tex, and the breaking elongation is 12.6-24.6%. DETAILED DESCRIPTION

[0042] The present invention is further described in detail below by specific examples. The raw materials used in the examples, unless otherwise specified, can be obtained from conventional commercial sources, or can be obtained by prior art methods. Unless otherwise specified, the tests or testing methods are conventional methods in the art.

[0043] The fiber types and parameters used in the embodiments of the present invention are shown in Table 1.

[0044] Table 1

[0045]

[0046]

[0047] Examples 1-9

[0048] Examples 1-9 each provide a core-spun yarn, which is composed of a core yarn and outer wrapping fibers disposed on the surface of the core yarn. The mass ratio of the core yarn and the ratios of various fibers in the outer wrapping fibers to the outer wrapping fibers are shown in Table 2.

[0049] Table 2

[0050]

[0051] It can be understood that Table 2 lists the mass ratio of the core yarn to the core-spun yarn, and the balance is the mass ratio of the outer wrapping fibers to the core-spun yarn. Taking Example 1 as an example, the mass ratio of the core yarn to the core-spun yarn is 25%, and the mass ratio of the outer wrapping fibers to the core-spun yarn is 75%.

[0052] Comparative Example 1

[0053] Comparative Example 1 uses a traditional evenly mixed spun yarn, in which the mass ratio of flame-retardant polyester fiber (A) is 25%, and the mass ratio of poly(m-phenylene isophthalamide) fiber (C) is 75%.

[0054] Performance Test

[0055] (1) The breaking strength and breaking elongation of the yarn were detected according to GB / T 3916-2013; the limiting oxygen index of the flame retardancy performance was detected according to GB / T5454-1997. The above test results are shown in Table 3.

[0056] Table 3

[0057] Number Limiting oxygen index % Breaking strength cN / tex Elongation at break % Example 1 31.2 33.8 23.8 Example 2 31.4 29.5 17.2 Example 3 30.8 34.2 24.6 Example 4 32.2 30.5 20.5 Example 5 32.8 25.2 15.8 Example 6 34.6 26.8 22.2 Example 7 33.4 24.2 12.6 Example 8 32.4 29.8 21.1 Example 9 32.2 30.8 20.8 Comparative example 1 30.1 26.5 16.4

[0058] As can be seen from Table 3, Example 1 and Comparative Example 1 use the same fibers, but the limiting oxygen index, breaking strength and breaking elongation of Example 1 are all better than those of Comparative Example 1, indicating that the core-spun yarn structure of the present invention can effectively improve the flame retardancy and strength performance of the yarn.

[0059] Compared with Example 1, although the breaking strength of D used in Example 2 is higher, because the breaking elongation of D is small, after twisting, the skew of the outer wrapping fibers increases, resulting in earlier breakage of the outer wrapping fibers. Therefore, the breaking elongation and breaking strength of Example 2 are relatively lower than those of Example 1.

[0060] (2) The yarns of Examples 1-9 and Comparative Example 1 were of the same specification of 200 g / m 2Preparation of woven plain fabric: The prepared fabric was tested for the index of the damage length of the flame retardant property in accordance with GB / T 5455-2014 Determination of the Damage Length, Afterflame and Afterglow Time of Textiles in the Vertical Direction; the tearing strength of the fabric was tested in accordance with GB / T 3917.3-2009 Textiles - Tear Properties of Fabrics - Part 3: Determination of Tear Force of Trapezoid Specimens; the shrinkage rate was tested in accordance with GA10-2014 Firefighter's Fire-Fighting Protective Clothing. The above test results are shown in Table 4.

[0061] Table 4

[0062]

[0063] As can be seen from Table 4, Example 1 and Comparative Example 1 used the same fibers, but the damage length and shrinkage rate of Example 1 were both smaller than those of Comparative Example 1, and the tearing strength of Example 1 was greater than that of Comparative Example 1, indicating that the core-spun yarn structure of the present invention can effectively improve the flame retardant and strength properties of the yarn.

[0064] Compared with Example 5, in Example 6, although G with a smaller elongation at break was used instead of E, since the proportion of the two high-elongation fibers C and F reached 70%, there were two fracture peaks in the yarn. The first peak appeared when the G fiber broke due to insufficient elongation, and a larger peak existed after the G fiber broke. When continuing to stretch, when C and F broke, the second peak appeared. At this time, although only the two fibers C and F were stressed, due to the increase in elongation, the strength of the core yarn was fully exerted, and it had greater strength and elongation than Example 5 instead.

[0065] The preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the described embodiments. Those skilled in the art can also make various equivalent variations or substitutions without departing from the spirit of the present invention, and these equivalent variations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A core-spun yarn, characterized in that, The core-spun yarn includes a core yarn and outer wrapping fibers provided on the surface of the core yarn. The core yarn includes flame-retardant polyester fibers, and the core yarn accounts for 15%-35% of the mass of the core-spun yarn; the breaking strength of the core yarn is ≥4.0 cN / dtex. The outer wrapping fibers include high-temperature carbonized and expanded fibers, and the high-temperature carbonized and expanded fibers include one or several of poly(m-phenylene isophthalamide) fibers, polysulfonamide, and flame-retardant acrylic fibers.

2. The core-spun yarn according to claim 1, characterized in that, The flame-retardant polyester fibers are filament fibers.

3. The core-spun yarn according to claim 1, characterized in that, The outer wrapping fibers further include one or several of polyimide, poly(arylene oxadiazole) fibers, poly(p-phenylene terephthalamide) fibers, and antistatic fibers.

4. The core-spun yarn according to claim 3, characterized in that, The outer wrapping fibers include poly(m-phenylene isophthalamide) fibers and poly(arylene oxadiazole) fibers; the poly(m-phenylene isophthalamide) fibers account for 40%-80% of the mass of the outer wrapping fibers, and the poly(arylene oxadiazole) fibers account for 20%-60% of the mass of the outer wrapping fibers.

5. The core-spun yarn according to claim 3, characterized in that, The outer wrapping fibers include poly(m-phenylene isophthalamide) fibers, poly(arylene oxadiazole) fibers, and flame-retardant acrylic fibers; the poly(m-phenylene isophthalamide) fibers account for 30%-50% of the mass of the outer wrapping fibers, the poly(arylene oxadiazole) fibers account for 20%-40% of the mass of the outer wrapping fibers, and the flame-retardant acrylic fibers account for 25%-45% of the mass of the outer wrapping fibers.

6. The core-spun yarn according to claim 3, characterized in that, The outer wrapping fibers further include poly(arylene oxadiazole) fibers and antistatic fibers; the antistatic fibers account for 2%-8% of the mass of the outer wrapping fibers, and the poly(arylene oxadiazole) fibers account for ≥20% of the mass of the outer wrapping fibers.

7. The core-spun yarn according to claim 1, characterized in that, The breaking elongation of the core-spun yarn is 70%-110% of the breaking elongation of the core yarn.

8. The core-spun yarn according to claim 1, characterized in that, For some of the outer wrapping fibers, the breaking elongation is 1-1.8 times that of the core yarn, and the mass proportion of this part of the fibers in the outer wrapping fibers is ≥65%.

9. The core-spun yarn according to claim 1, wherein, The core-spun yarn is prepared by compact spinning or vortex spinning.

10. A textile, characterized in that, It includes the core-spun yarn according to any one of claims 1-9.

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