A reusable fabric and a method for making the same

Abstract

The application discloses an easy-to-reuse fabric and a preparation method thereof. The easy-to-reuse fabric is a knitted fabric or a woven fabric obtained by weaving alkali-soluble polyester filaments and composite yarns; the composite yarns are obtained by plying and reducing twist of the alkali-soluble polyester filaments and low-twist cotton yarns. The alkali-soluble polyester and the low-twist cotton yarns are plied and twisted to reduce the twist of the cotton yarns, the twist of the cotton yarns is further reduced, the overall strength of the yarns can still be ensured, the preparation for the subsequent disassembly and opening of the cotton fibers is facilitated, and the wearability of the easy-to-reuse fabric is not affected.

Description

Technical Field

[0001] This invention relates to the field of textile technology, specifically to an easily reusable fabric and its preparation method. Background Technology

[0002] With the increasing consumption of textiles, the amount of waste textiles generated is also increasing year by year. The recycling of waste textiles is becoming an increasingly serious problem for the textile industry. Therefore, the high-value recycling of waste textiles is urgently needed.

[0003] Currently, the commonly used recycling methods are mainly divided into mechanical opening recycling, chemical dissolution recycling, and physical melt recycling. These recycling methods are all based on the recycling of conventional fabrics. This has no impact on chemical dissolution recycling and physical melt recycling, but it has a big problem for mechanical opening recycling. Because of the twist of the yarn and the interlacing and looping relationship of the fabric, it is difficult to separate individual fibers from the fabric. The end result is that the quality of the fibers obtained by mechanical opening is very poor, especially in terms of length and strength.

[0004] In recent years, those skilled in the art have conducted a series of studies and proposed some methods to achieve the convenience and high value of recycling by designing reusable fabrics. For example, Chinese patent CN109505046A discloses "A Novel Recyclable Fabric", in which the weft yarn is polylactic acid fiber and the warp yarn is cotton yarn. After weaving the fabric, the polylactic acid fiber is removed to obtain pure cotton yarn, realizing the change from fabric state to yarn state, which greatly reduces the difficulty of mechanical opening. However, the wearability of polylactic acid fiber is generally poor and it does not have the characteristics of long-term use. Moreover, the obtained cotton yarn still has a high twist, making it still difficult to open.

[0005] To reuse textiles more efficiently and with higher value, it is necessary to implement easy-to-reuse operations from the very beginning of the fabric design stage. Summary of the Invention

[0006] To solve at least one of the above technical problems, the present invention provides an easily reusable fabric and a method for preparing the same.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: The present invention provides an easy-to-use fabric, which is a knitted or woven fabric woven from alkali-soluble polyester filament and composite yarn; the composite yarn is obtained by plying and reducing the twist of alkali-soluble polyester filament and low-twist cotton yarn.

[0008] This invention utilizes alkali-soluble polyester filament and low-twist cotton yarn to reduce twist, which can further reduce the twist of the cotton yarn while ensuring the overall strength of the yarn. This prepares the fabric for the subsequent disassembly and opening of the cotton fibers without affecting the wearability of the reusable fabric.

[0009] In this invention, the twist of the low-twist cotton yarn is 30% to 60% lower than that of conventional cotton yarn. For example, the twist coefficient α of conventional cotton yarn is... e ≈3.2~3.6; Twist coefficient α of low-twist cotton yarn e ≈1.3~3.0. The alkali-soluble polyester filament is a type of filament that can be dissolved by low concentrations of sodium hydroxide (e.g., 20 g / L~100 g / L).

[0010] According to the reusable fabric of the present invention, preferably, in the composite yarn, the mass ratio of the alkali-soluble polyester filament to the low-twist cotton yarn is 1:9 to 4:6.

[0011] According to the reusable fabric of the present invention, preferably, the twist index (TPI) of the composite yarn is 5 to 10.

[0012] According to the reusable fabric of the present invention, preferably, the fineness of the low-twist cotton yarn is 10~100S.

[0013] According to the reusable fabric of the present invention, preferably, the fineness of the alkali-soluble polyester filament in the composite yarn is 10~100D.

[0014] The fineness of the alkali-soluble polyester filament woven together with the composite yarn is 50~200D.

[0015] According to the reusable fabric of the present invention, preferably, the knitted fabric includes loops formed by the alkali-soluble polyester filaments and loops formed by the composite yarns, which are interlocked at intervals. The knitted fabric includes a row of loops formed by alkali-soluble polyester filaments alone, which facilitates the disintegration of the fabric during recycling by alkali dissolving the loop.

[0016] According to the reusable fabric of the present invention, preferably, the warp of the woven fabric is the composite yarn and the weft is the alkali-soluble polyester filament; or the weft is the composite yarn and the warp is the alkali-soluble polyester filament. The knitted fabric includes a single loop made of alkali-soluble polyester filament, which facilitates the disintegration of the fabric during recycling by alkali dissolving the loop.

[0017] In another aspect, the present invention provides a method for preparing any one of the above-mentioned reusable fabrics, wherein the preparation method includes the following steps: Composite yarn was prepared by plying and reducing the twist of alkali-soluble polyester filament and low-twist cotton yarn. Knitted fabric can be obtained by knitting using alkali-soluble polyester filament and the composite yarn, or woven fabric can be obtained by weaving using alkali-soluble polyester filament and the composite yarn.

[0018] In some preferred embodiments, during the knitting process, loops formed using alkali-soluble polyester filaments and loops formed using the composite yarn are interlocked to obtain the knitted fabric. In some preferred embodiments, during the woven fabric process, alkali-soluble polyester filaments are used in the warp or weft direction, while the composite yarn is used in the other direction. In these preferred embodiments, utilizing alkali-soluble polyester filaments to form individual loops on the knitted fabric or to arrange them individually in the warp or weft direction of the woven fabric helps to break down the fabric structure into a yarn structure, greatly reducing the difficulty of opening the yarn.

[0019] The reusable fabric provided by this invention can be loosened and recycled by dissolving polyester after recycling. The sodium hydroxide solution used to dissolve the polyester has a concentration of 20g / L to 100g / L, a temperature of 70℃ to 130℃, and a time of 10 to 30 minutes.

[0020] This invention is based on the principle of mechanical and physical opening, using suitable alkali-soluble polyester filaments to transform the fabric state into a yarn state, thus significantly reducing the difficulty of opening and resulting in a qualitative improvement in the length and strength of the recycled fibers. Furthermore, by using alkali-soluble polyester filaments to untwist pure cotton low-twist yarn, the final dissolved cotton yarn has a very low twist, further reducing the difficulty of opening and maximizing the protection of the quality of the recycled fiber opening process. Simultaneously, the alkali-soluble polyester filaments selected in this invention ensure that the fabric provides the necessary performance throughout its entire wear life. Moreover, the preparation method of this invention is convenient, easy to implement, and suitable for widespread use. Detailed Implementation

[0021] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0022] All numerical specifications in this invention (e.g., temperature, time, concentration, and weight, including ranges for each) are generally approximate values ​​that may be changed (+) or (-) in increments of 0.1 or 1.0. All numerical specifications are to be understood as being preceded by the term "about".

[0023] Example 1: This embodiment prepares a 24S pique knitted fabric, including the following processes: A composite yarn is obtained by plying and untwisting 26S low-twist cotton yarn and 20D alkali-soluble polyester filament at a mass ratio of 9:1. The twist index (TPI) of the 26S low-twist cotton yarn is 14.5, which can be reduced to 7.5 after plying and untwisting.

[0024] The resulting composite yarn and a 150D alkali-soluble polyester filament are woven together in loops to obtain a knitted fabric.

[0025] After a full set of fabric performance tests, all test items of the fabric prepared in this embodiment met the standard limits; using the GB / T 8629 washing procedure test, the warp and weft dimensional change rate of the fabric was stably controlled within -2.3%~0.9%; and according to the GB / T19976 method, the bursting strength of the fabric can reach 487N.

[0026] Dissolution process: The fabric was dissolved in a 30 g / L NaOH solution at a liquor ratio of 1:10 for 30 minutes at 95°C, resulting in the disintegration and unwinding of the 150D alkali-soluble polyester filament.

[0027] After alkali dissolution treatment, the fabric state is transformed into yarn state, and the yarn twist is very low. After physical and mechanical opening, the length of reusable fiber can be increased by more than 5mm, the fiber yield can be increased by 30%, and the short fiber rate can be reduced by 10%.

[0028] Example 2

[0029] This embodiment prepares a plain weave woven fabric, including the following processes: A composite yarn is obtained by plying and untwisting 26S low-twist cotton yarn and 20D alkali-soluble polyester filament at a mass ratio of 9:1. The twist index (TPI) of the 26S low-twist cotton yarn is 14.5, which can be reduced to 7.5 after plying and untwisting.

[0030] The resulting composite yarn is used as the weft yarn and interwoven with a 150D alkali-soluble polyester filament as the warp yarn to obtain a woven fabric.

[0031] After a full set of fabric performance tests, all test items of the fabric prepared in this embodiment met the standard limits; using the GB / T 8629 4N(5A)-F-2017 method, the warp and weft dimensional change rate of the fabric after washing was stably controlled within -2% to -4%; according to the GB / T 3917.1-2009 method, the weft tear of the fabric can reach 22N.

[0032] Dissolution process: The fabric was dissolved in a 30g / L NaOH solution at a liquor ratio of 1:10 for 30 minutes at 95°C, so that the warp 150D alkali-soluble polyester filaments were dissolved and the weft yarns were separated from the fabric.

[0033] After alkali dissolution treatment, the fabric state is transformed into the yarn state, and the yarn twist is very low. After physical and mechanical opening, the length of reusable fiber can be increased by more than 4mm, the fiber yield can be increased by 33%, and the short fiber rate can be reduced by 15%.

[0034] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A reusable fabric, characterized in that, The reusable fabric is a knitted or woven fabric woven from alkali-soluble polyester filament and composite yarn; the composite yarn is obtained by plying and reducing the twist of alkali-soluble polyester filament and low-twist cotton yarn.

2. The reusable fabric according to claim 1, characterized in that, In the composite yarn, the mass ratio of the alkali-soluble polyester filament to the low-twist cotton yarn is 1:9 to 4:

6.

3. The reusable fabric according to claim 1, characterized in that, The twist (TPI) of the composite yarn is 5-10.

4. The reusable fabric according to claim 1, characterized in that, The fineness of the low-twist cotton yarn is 10~100S.

5. The reusable fabric according to claim 1, characterized in that, The fineness of the alkali-soluble polyester filament in the composite yarn is 10~100D; and / or The fineness of the alkali-soluble polyester filament woven together with the composite yarn is 50~200D.

6. The reusable fabric according to claim 1, characterized in that, The knitted fabric includes loops formed by the alkali-soluble polyester filaments and loops formed by the composite yarns, which are interlocked at intervals to form loops.

7. The reusable fabric according to claim 1, characterized in that, The woven fabric has a warp yarn of the composite yarn and a weft yarn of the alkali-soluble polyester filament; or a weft yarn of the composite yarn and a warp yarn of the alkali-soluble polyester filament.

8. A method for preparing the reusable fabric according to any one of claims 1-7, characterized in that, The preparation method includes the following steps: Composite yarn was prepared by plying and reducing the twist of alkali-soluble polyester filament and low-twist cotton yarn. Knitted fabric can be obtained by knitting using alkali-soluble polyester filament and the composite yarn, or woven fabric can be obtained by weaving using alkali-soluble polyester filament and the composite yarn.

9. The preparation method according to claim 8, characterized in that, In the process of knitting the fabric, loops formed by alkali-soluble polyester filaments and loops formed by composite yarns are interlocked to obtain the knitted fabric.

10. The preparation method according to claim 8, characterized in that, In the weaving process of the woven fabric, alkali-soluble polyester filaments are used in the warp or weft direction, and the composite yarn is used in the other direction.