阅读说明：本技术 一种从废旧锦纶混纺织物中回收锦纶的工艺及回收产物 (Process for recovering chinlon from waste chinlon blended fabric and recovered product ) 是由 赖文钦 柯希贤 朱恩斌 林飞芳 姚仲鹏 陆东东 吴建通 张俊峰 于 2021-09-13 设计创作，主要内容包括：本发明涉及IPC D01G11/00领域,尤其涉及一种从废旧锦纶混纺织物中回收锦纶的工艺及回收产物。包括以下步骤：使用有机萃取剂对废旧锦纶混纺织物进行萃取,得到萃取液；降低萃取液的温度,收集降温过程中析出的固体；对收集到的固体进行纯化,得到锦纶回收产物。本发明采用醇类萃取剂实现锦纶混纺织物中锦纶与非锦纶组分的有效分离,得到高回收率的纺织物纯品,对于纺织品(尤其是锦纶)的再生利用具有重要意义；采用特定回收装置配合萃取剂作用,萃取的同时进行分离,在简便实用的工艺基础上提升了回收效率；回收过程中摒弃了毒性大、成本高的有机溶剂,实现了安全、环保、高效、选择性强的回收锦纶工艺。(The invention relates to the field of IPC D01G11/00, in particular to a process for recovering chinlon from waste chinlon blended fabric and a recovered product. The method comprises the following steps: extracting the waste nylon blended fabric by using an organic extractant to obtain an extract liquor; reducing the temperature of the extraction liquid, and collecting solids precipitated in the temperature reduction process; purifying the collected solid to obtain a nylon recovered product. The alcohol extractant is adopted to realize the effective separation of the chinlon and non-chinlon components in the chinlon blended fabric, so that the pure textile with high recovery rate is obtained, and the method has important significance for the recycling of textiles (especially chinlon); a specific recovery device is adopted to match with the action of an extracting agent, and separation is carried out while extraction is carried out, so that the recovery efficiency is improved on the basis of a simple and practical process; organic solvents with high toxicity and high cost are abandoned in the recovery process, and the polyamide fiber recovery process with safety, environmental protection, high efficiency and strong selectivity is realized.)

1. A process for recovering chinlon from waste chinlon blended fabric is characterized by comprising the following steps:

s1, extracting the waste nylon blended fabric by using an organic extracting agent to obtain an extraction liquid;

s2, reducing the temperature of the extraction liquid, and collecting solids precipitated in the temperature reduction process;

and S3, purifying the collected solid to obtain a nylon recovered product.

2. The process for recovering chinlon from waste chinlon blended fabric according to claim 1, wherein the step S1 is specifically that the waste chinlon blended fabric is pretreated, then transferred to an autoclave A, an organic extractant is added into the autoclave A, the autoclave A is sealed, and the extraction is completed after the action of the organic extractant at an extraction temperature of 100 ℃ and 190 ℃ for 20-120min, so as to obtain an extraction liquid; and simultaneously obtaining a non-chinlon recovered product.

3. The process for recovering chinlon from waste chinlon blended fabric according to claim 1 or 2, wherein the step S2 is specifically that the extract is transferred to an autoclave B, the temperature of the autoclave B is reduced to 0-70 ℃, and solids precipitated in the cooling process are collected by a physical separation method.

4. The process for recovering nylon from waste nylon blended fabric according to claim 3, wherein the physical separation method comprises one or more of decantation operation, filtration operation, centrifugation operation and sedimentation operation.

5. The process for recovering nylon from the waste nylon blended fabric according to any one of claims 1-3, wherein the step S2 is specifically that the extract is transferred to an autoclave B, the temperature of the autoclave B is reduced to 10-35 ℃, and solids precipitated in the cooling process are collected by a physical separation method.

6. The process for recovering chinlon from waste chinlon blended fabric according to claim 5, wherein the high-pressure kettle B is preheated before being contacted with the extract liquor; i.e. the initial temperature of autoclave B was the same as the extraction temperature of step S1.

7. The process for recovering chinlon from the waste chinlon blended fabric according to any one of claims 1-6, wherein the raw materials of the waste chinlon blended fabric at least comprise chinlon fibers and further comprise one or more of cotton fibers, polyester fibers, spandex fibers, silk fibers, acrylic fibers and polypropylene fibers.

8. The process for recovering chinlon from waste chinlon blending fabrics according to any one of claims 1-7, wherein the organic extracting agent comprises one or more of alcohols, ethers, ketones and esters.

9. The process for recovering chinlon from waste chinlon blended fabric according to any one of claims 1 to 8, wherein in the step S1, the solid-to-liquid ratio of the waste chinlon blended fabric to the organic extractant is 1: (3-80) g/mL.

10. A recovered product for recovering chinlon from waste chinlon blended fabric, which is characterized in that the recovered product is obtained by the process for recovering chinlon from the waste chinlon blended fabric according to any one of claims 1 to 9.

Technical Field

The invention relates to the field of IPC D01G11/00, in particular to a process for recovering chinlon from waste chinlon blended fabric and a recovered product.

Background

Chinlon is the second largest synthetic fiber, and the dosage is second only to that of terylene. In order to simultaneously improve multiple performances of the textile such as mechanical strength, skin-friendly property and the like, other types of fibers are often blended with the nylon textile, such as terylene, spandex, cotton and the like; and the traditional mechanical method is difficult to realize the separation of all components in the nylon blended fabric. At present, the nylon blended fabric is recycled mainly by extruding and granulating after high-temperature melting of a screw, the quality of the obtained regenerated product cannot be guaranteed, the regenerated product is mostly low-grade products, the added value is low, and most of the regenerated products are used in the field of low-end plastics or used as resin fillers; the current nylon blended fabric has low recovery rate and is a bottleneck of technical development in the textile field.

The nylon fiber is high in price, and the nylon component is separated and recovered from the nylon blended fabric, so that the method is an effective way for solving the problem that the waste nylon fiber blended fabric cannot be reused in a high-valued and comprehensive manner. The traditional technical means utilizes the selective dissolving effect of N, N-Dimethylformamide (DMF) on nylon to separate and recover nylon fibers from nylon/spandex fabrics, but the method still cannot realize commercial application due to the toxicity of the DMF and the expensive solvent recovery cost. Chinese patent CN107308905 discloses a method for separating components of waste polyester-cotton blended fabric, which adopts ethylene glycol as an alcoholysis agent and combines a centrifugal roller drying technology to realize high-efficiency polyester/cotton separation. The method realizes the separation of the blended fabric, but as for the separation product, only the solid cotton yarn in the blended fabric can be collected, and the terylene in the blended fabric is completely alcoholyzed under the action of the alcoholysis agent and the catalyst and cannot be recycled. The prior art still has the technical defects that the recovery rate of target textile fabrics is low, the target textile fabrics in the blended fabric can not be utilized, and the recovery rate of the fabrics and the environmental protection performance of the operation are difficult to be considered simultaneously.

Based on the method, the recovery process of the chinlon in the blended fabric, which has the advantages of strong targeting property, high recovery rate and safe and environment-friendly recovery scheme, is explored, the large-batch recycling of the chinlon is realized, and the method has important significance to the technical field of textiles.

Disclosure of Invention

In order to solve the defects of the prior separation and recovery of the waste nylon blended fabric, the invention provides a method for recovering nylon from the waste nylon blended fabric.

The invention provides a process for recovering chinlon from waste chinlon blended fabric in a first aspect, which comprises the following steps:

s1, extracting the waste nylon blended fabric by using an organic extracting agent to obtain an extraction liquid;

s2, reducing the temperature of the extraction liquid, and collecting solids precipitated in the temperature reduction process;

and S3, purifying the collected solid to obtain a nylon recovered product.

In some preferred embodiments, the step S1 is specifically to pretreat the waste nylon blended fabric, then transfer the pretreated waste nylon blended fabric to an autoclave a, add an organic extractant to the autoclave a, seal the autoclave a, and perform extraction at an extraction temperature of 100-; and simultaneously obtaining a non-chinlon recovered product.

Further preferably, the extraction temperature is 100-160 ℃.

Preferably, the pretreatment operation is that the waste nylon blended fabric is dried for 4-10h at the temperature of 70-85 ℃.

In some preferred embodiments, the step S2 is specifically that the extract is transferred to autoclave B, the temperature of autoclave B is reduced to 0-70 ℃, and a physical separation method is adopted to collect solids precipitated in the cooling process; further preferably, the temperature of the autoclave B is reduced to 10-35 ℃, and the separation effect is better.

Further preferably, the temperature of the autoclave B is reduced to 10-35 ℃, and the separation effect is better.

In some preferred embodiments, a polytetrafluoroethylene filter bag is arranged in the autoclave a to contain the waste nylon blended fabric.

Further preferably, the particle size of the polytetrafluoroethylene filter bag is 10-50 meshes.

In some preferred embodiments, the exterior of both autoclave a and autoclave B are wrapped with a heat and temperature retention device.

In some preferred embodiments, the bottom of the autoclave A is provided with a discharge hole, and the top of the autoclave B is provided with a feed hole; the discharge port is connected with the feed inlet through a pipeline.

In some preferred embodiments, the step S3 is specifically to put the collected solid at 50-90 ℃ and vacuum-dry to constant weight, so as to obtain the nylon recovered product.

In some preferred embodiments, the autoclave B is preheated before being contacted with the extraction liquid; i.e. the initial temperature of autoclave B was the same as the extraction temperature of step S1.

Further preferably, the physical separation method comprises a combination of one or more of a decantation operation, a filtration operation, a centrifugation operation, and a settling operation.

In some preferred embodiments, the raw material of the waste nylon blended fabric at least comprises nylon fibers, and further comprises one or more of cotton fibers, polyester fibers, spandex fibers, silk fibers, acrylic fibers and polypropylene fibers.

Further preferably, the nylon fiber is nylon 6 fiber and/or nylon 66 fiber.

Preferably, the raw materials of the waste nylon blended fabric further comprise one or more of cotton fibers, polyester fibers and spandex fibers.

In some preferred embodiments, the organic extractant includes one or more of alcohols, ethers, ketones, and esters.

Further preferably, the organic extractant is an alcohol compound, and the boiling point of the alcohol compound is 50-80 ℃.

Still more preferably, the organic extractant is at least one of methanol (boiling point: 64.7 ℃) and ethanol (boiling point: 78.3 ℃).

In some preferred embodiments, in the step S1, the solid-to-liquid ratio of the waste nylon blended fabric to the organic extractant is 1: (3-80) g/mL; preferably 1: (5-50) g/mL.

The invention adopts the polytetrafluoroethylene filter bag to contain the waste chinlon blended fabric, completely immerses the waste chinlon blended fabric in the specific organic extracting agent, and quickly and effectively extracts the chinlon in the blended fabric into the organic extracting agent under the conditions of high temperature and high pressure. Along with the process of transferring the extract liquid from the high-pressure kettle A to the high-pressure kettle B, filtering the extract liquid by the filter bag while flowing, wherein the residual fabric which is not extracted in the high-pressure kettle A cannot pass through the pores of the filter bag and is effectively trapped in the filter bag, namely a non-chinlon recovered product; the chinlon component is transferred from the high-pressure kettle A to the high-pressure kettle B along with the organic extractant; the extraction and the separation of the blended fabric are carried out simultaneously, and the recovery efficiency of different recovery products is obviously improved.

After the extract liquid enters the high-pressure kettle B, the chinlon dissolved in the organic extractant is gradually precipitated in a solid state along with the cooling of the environment, the solid is collected and dried and purified, and a pure chinlon recovered product can be obtained. The invention adopts a simple and safe recovery process, collects the high-purity chinlon and the high-purity cotton fiber, realizes the effective separation of the blending waste, and provides a brand-new and effective idea for the recycling of textiles.

The invention provides a recovery product for recovering chinlon from waste chinlon blended fabric in a second aspect, wherein the recovery product is obtained according to the process for recovering chinlon from the waste chinlon blended fabric.

Has the advantages that:

the invention provides a process for recovering chinlon from waste chinlon blended fabric, which has the following advantages:

(1) the organic extractant is adopted to realize the effective separation of the chinlon and non-chinlon components in the chinlon blended fabric, so that the pure textile with high recovery rate is obtained, and the method has important significance for the recycling of textiles (especially chinlon);

(2) organic solvents with high toxicity and high cost are abandoned in the recovery process, and the safe and environment-friendly polyamide fiber recovery process is realized by adopting the alcohol extracting agent which is low in price, low in boiling point and easy to recover;

(3) the separation and recovery conditions of the invention have the characteristics of strong dissolubility to the chinlon component and good extraction effect, and do not extract other fiber components, such as cotton, terylene, spandex and other fibers; can efficiently and economically recover the nylon component from the waste nylon blended fabric, and is beneficial to realizing the high added value utilization of the waste nylon blended fabric.

(4) The specific recovery device is adopted to match with the action of the extracting agent, separation is realized during extraction, and the recovery efficiency is improved on the basis of a simple and practical process.

Drawings

FIG. 1 is a schematic view of a recovery apparatus used in the recovery process in example 1 of the present invention

Detailed Description

Example 1.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, which comprises the following steps:

s1, extracting the waste nylon blended fabric by using an organic extracting agent to obtain an extraction liquid;

s2, reducing the temperature of the extraction liquid, and collecting solids precipitated in the temperature reduction process;

and S3, purifying the collected solid to obtain a nylon recovered product.

The step S1 is specifically that the waste chinlon blended fabric is pretreated, then the pretreated waste chinlon blended fabric is transferred to an autoclave A, an organic extracting agent is added into the autoclave A, the autoclave A is sealed, and the extraction is finished by acting for 20-120min at the extraction temperature of 135 ℃ to obtain an extraction liquid; and simultaneously obtaining a non-chinlon recovered product.

The pretreatment operation is that the waste nylon blended fabric is dried for 6 hours at 80 ℃.

And the step S2 is specifically to transfer the extract into the high-pressure kettle B, reduce the temperature of the high-pressure kettle B to 26 ℃, and collect the solid precipitated in the temperature reduction process by adopting the filtration operation.

A polytetrafluoroethylene filter bag is arranged in the autoclave A to contain the waste nylon blended fabric, and a non-nylon recovered product is contained in the filter bag after the extraction in the step S1.

The particle size of the polytetrafluoroethylene filter bag is 10 meshes.

A discharge hole is formed in the bottom of the high-pressure kettle A, and a feed hole is formed in the top of the high-pressure kettle B; the discharge port is connected with the feed port through a pipeline; both autoclave a and autoclave B were provided with a stirrer (see fig. 1).

And the step S3 is specifically that the collected solid is placed at 80 ℃ for vacuum drying until the weight is constant (the weight deviation is less than or equal to 0.1g), and a nylon recovered product is obtained.

Preheating the autoclave B in advance before the autoclave B is contacted with the extraction liquid; i.e. the initial temperature of autoclave B was the same as the extraction temperature of step S1.

The waste nylon blended fabric is cotton/nylon 6 waste white cloth; the weight ratio of the cotton fibers to the nylon 6 fibers in the cotton/nylon 6 waste white cloth is 60: 40.

the organic extractant is an alcohol compound, specifically methanol, and has a boiling point of 64.7 ℃.

In the step S1, the solid-to-liquid ratio of the waste nylon blended fabric to the organic extractant is 1: 40 g/mL.

In a second aspect, the present invention provides a recovered product for recovering nylon from a waste nylon blended fabric, where the recovered product is obtained according to the above process for recovering nylon from a waste nylon blended fabric.

Example 2.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 1; the difference is that the waste chinlon blended fabric is terylene/spandex waste white cloth; the weight ratio of the polyester fibers to the spandex fibers in the waste polyester/spandex white cloth is 95: 5.

example 3.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 1; the difference is that the waste chinlon blended fabric is waste terylene/cotton white cloth; the weight ratio of the polyester fibers to the cotton fibers in the waste polyester/cotton white cloth is 65: 35.

example 4.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 1; the difference is that the organic extractant is ethanol, and the boiling point is 78.3 ℃.

Example 5.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 2; the difference is that the organic extractant is ethanol.

Example 6.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 3; the difference is that the organic extractant is ethanol.

Example 7.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 1; except that the extraction temperature was 100 ℃.

Example 8.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 1; except that the extraction temperature was 160 ℃.

Example 9.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 1; the difference is that the extraction temperature is 110 ℃; the organic extractant is ethanol.

Example 10.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 1; the difference is that the extraction temperature is 160 ℃; the organic extractant is ethanol.

Example 11.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 2; except that the extraction temperature was 160 ℃.

Example 12.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 2; the difference is that the extraction temperature is 160 ℃; the organic extractant is ethanol.

Example 13.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 3; except that the extraction temperature was 160 ℃.

Example 14.

The embodiment provides a process for recovering chinlon from waste chinlon blended fabric, and the specific implementation mode is the same as that in embodiment 3; the difference is that the extraction temperature is 160 ℃; the organic extractant is ethanol.

Performance test method

And (3) recovery rate:

and respectively calculating the recovery rates of the products recovered in the high-pressure kettles A and B by taking the total weight of the waste nylon blended fabric subjected to initial pretreatment as a reference M0.

The recovery of product (non-chinlon component) from autoclave a was 100% (weight of residue in polytetrafluoroethylene filter bags from autoclave a)/M0.

The recovery rate of the product (chinlon component) recovered in autoclave B was (weight of the precipitate in autoclave B)/M0 × 100%.

Note: the weight of the residue in the polytetrafluoroethylene filter bag in autoclave A and the weight of the precipitate in autoclave B were masses after vacuum drying at 80 ℃ to a constant weight.

Performance test data

Table 1.

According to the results of the embodiments 1-14 of the invention, the methanol or ethanol can effectively extract and recover the nylon component in the waste nylon blended fabric at the extraction temperature of 100-160 ℃, and has almost no extraction effect on other components, such as cotton, terylene or spandex; the invention can realize the recycling of the chinlon in the blended fabric.