阅读说明：本技术 一种含可溶纤维的废旧织物回收利用方法 (Method for recycling waste fabric containing soluble fibers ) 是由 张晏铭 余燕平 刘卫国 于 2020-05-11 设计创作，主要内容包括：本发明涉及一种含可溶纤维的废旧织物回收利用方法,包括：将织物放置在浓度较低的碱性溶液中,可溶性聚酯纤维溶解,剩下的松散纤维集合体经过剥色处理和烘干后,再经梳棉机轻柔梳理,得到再生天然纤维。对溶解液进行提纯分离后,可得到高纯度的对苯二甲酸和乙二醇,再次用于可溶性聚酯切片的聚合。(The invention relates to a method for recycling waste fabrics containing soluble fibers, which comprises the following steps: and (3) placing the fabric in an alkaline solution with lower concentration, dissolving the soluble polyester fiber, stripping and drying the remaining loose fiber aggregate, and then slightly carding by a carding machine to obtain the regenerated natural fiber. After the dissolved solution is purified and separated, high-purity terephthalic acid and ethylene glycol can be obtained and used for polymerization of the soluble polyester chips again.)

1. The recyclable and reusable fabric is characterized by being a weft-knitted fabric formed by alternating blended yarns of natural cellulose fibers and soluble polyester filaments.

2. The fabric according to claim 1, wherein the natural cellulose is cotton fiber and/or hemp fiber.

3. The fabric of claim 1, wherein the blend ratio of the soluble polyester fiber to the natural cellulose fiber is 50/50 or 35/65.

4. A method of recycling a fabric, comprising:

(1) subjecting the fabric of claim 1 to an alkali treatment to obtain a mass of natural fibers and an alkali solution;

(2) untwisting and carding the fiber mass of the natural fibers in the step (1) to obtain regenerated natural fibers;

and (2) purifying and separating the alkali dissolving solution in the step (1) to obtain terephthalic acid and ethylene glycol.

5. The method as claimed in claim 4, wherein the alkali treatment in the step (1) is carried out by dipping the waste fabric in alkali liquor, and the bath ratio is 1: 10.

6. The method according to claim 5, wherein the alkali treatment is specifically: the concentration of the alkali liquor is 4-5g/L NaOH solution, the treatment temperature is 100 ℃, and the treatment time is 0.5-2 h.

7. The method according to claim 4, wherein the purification and separation in the step (2) are specifically: introducing an alkali solution into a regulating reservoir, sequentially carrying out pretreatment and a membrane system, then entering an acid separation tank, filtering wastewater in the acid separation tank, and separating out terephthalic acid in the process to obtain terephthalic acid; and (4) separating the waste liquid after acid precipitation by a filtering membrane system to obtain the ethylene glycol.

8. The method of claim 7, wherein the pretreatment is a pH adjustment.

Technical Field

The invention belongs to the field of waste fabric recovery, and particularly relates to a method for recycling soluble fiber-containing waste fabrics.

Background

Countless textiles worldwide become waste textiles that cannot be reused, or are of low grade, which causes waste of resources and environmental pollution problems. The recycling of waste textiles is a new low-carbon and environment-friendly development trend, so that resources are saved, and the environment is protected.

According to statistics, the processing amount of textile fibers per year in China exceeds 5000 ten thousand tons, more than 2000 ten thousand tons of waste textiles are generated, only 15% of the waste textiles are recycled, 85% of the waste textiles are sent to a refuse landfill or are burnt, a large amount of waste textiles are continuously accumulated, and the waste textiles cannot be recycled, so that the current situation that resources are increasingly tense is caused. At present, most of waste textiles are mainly recovered by a physical recovery method, such as primary mechanical processing or incineration, so that the recovery value and the regeneration economic benefit of the waste textiles are greatly limited. In recent years, in the aspect of chemical recovery, China makes some progress in the aspect of recycling single-component waste cotton fabrics or waste polyester fabrics, and the progress in the aspect of efficient separation and recycling of components of waste polyester-cotton blended fabrics is slower, so that the recycling and reusing of polyester-cotton textiles are greatly influenced.

The existing textile fibers have no technology and products which can be simply treated and recycled, and the important reasons are that the textile raw materials are complex in composition, color and ready-made clothes accessories, the fabric structure is compact, and the fiber damage is large after opening and carding. At present, in the market, only the high-value textiles such as pure-spun cashmere, aramid fiber and the like are subjected to opening and carding to obtain fibers with low strength and short length, and the fiber utilization rate is low.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for recycling waste fabrics containing soluble fibers, and overcomes the defects of compact fabric structure, large fiber damage after opening and carding, complex recycling process, high cost and the like in the prior art. The method of the present invention can directly recover regenerated natural fiber and high-purity terephthalic acid and ethylene glycol.

The invention relates to a recyclable and reusable fabric which is characterized by being a weft-knitted fabric formed by alternating blended yarns of natural cellulose fibers and soluble polyester filaments.

The natural cellulose is cotton fiber and/or hemp fiber.

The fabric is prepared by the following method: the natural cellulose fiber and the soluble polyester fiber are blended according to a certain proportion, and the blended yarn and the soluble polyester filament are woven into the fabric.

Weaving the blended yarn and the soluble polyester filament yarn by using a circular knitting machine to obtain: the weft knitted fabric with the mixed yarn and the soluble polyester filament yarn alternated has good detachability, and the soluble polyester fiber and the soluble polyester filament yarn are dissolved to form the yarn which is singly dispersed and only contains the non-soluble natural fiber, so the yarn is easy to be combed and loosened into the closely arranged natural cellulose fiber, and the damage to the fiber is small.

The blending ratio of the soluble polyester fiber to the natural cellulose fiber is 50/50 or 35/65.

The invention relates to a recycling method of fabric, which comprises the following steps:

(1) carrying out low-alkali treatment on the fabric according to claim 1, dissolving soluble polyester fibers and soluble polyester filaments to obtain fiber clusters of natural fibers (namely loose fiber aggregates of the natural fibers) and an alkali dissolving solution;

(2) untwisting and carding the fiber mass of the natural fibers in the step (1) to obtain regenerated natural fibers;

and (2) purifying and separating the alkali dissolving solution in the step (1) to obtain terephthalic acid and ethylene glycol, which can be used for polymerization of soluble polyester chips again.

In the step (1), the alkali treatment is carried out by dipping the waste fabric in alkali liquor, and the bath ratio is 1: 10.

The alkali treatment specifically comprises the following steps: the concentration of the alkali liquor is 4-5g/L NaOH solution, the treatment temperature is 100 ℃, and the treatment time is 0.5-2 h.

Untwisting and carding the fiber mass in the step (2) are as follows: untwisting on a yarn twister, and combing by using a dense comb.

The purification and separation in the step (2) are specifically as follows: introducing an alkali solution into a regulating reservoir, sequentially carrying out pretreatment and a membrane system, then entering an acid separation tank, filtering wastewater in the acid separation tank, and separating out terephthalic acid in the process to obtain terephthalic acid; and (4) separating the waste liquid after acid precipitation by a filtering membrane system to obtain the ethylene glycol.

The pretreatment is pH adjustment, and the pH value is 7.

Advantageous effects

According to the invention, after soluble fibers are dissolved in waste fabrics containing soluble fibers through low-alkali treatment, the non-soluble natural cellulose fibers are convenient to open and comb by utilizing the dispersibility of weft knitted fabrics, and can be used after gentle combing with small damage to the strength and length of the fibers due to loose fiber aggregates, the damage to the fibers is small, the utilization rate is high, the strength after treatment is kept at 95%, and the length retention rate is more than 90%. The spinnability and serviceability of the non-soluble natural cellulose fiber are ensured. The dissolved solution can be purified and separated to obtain high-purity terephthalic acid and ethylene glycol, and can be used for polymerization of soluble polyester chips for producing soluble polyester fibers, so that the efficient cyclic utilization of the fibers is realized.

Drawings

FIG. 1 is a schematic diagram of a natural cellulose fiber recycling process of the present invention;

FIG. 2 is a schematic view of the recovery structure of the alkali dissolution liquid of the present invention.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.