CN114457582A - Swelling method of ramie yarn - Google Patents

Abstract

The invention provides a method for swelling ramie yarn, which comprises the following steps: step 1: adding ramie yarn into a closed container, and then adding liquid ammonia into the closed container to react the liquid ammonia with the ramie yarn; and 2, step: taking out the reacted ramie yarn, and putting the ramie yarn into a high-temperature steam box to react so as to make ammonia flow out; and 3, step 3: the dried ramie yarn is taken out and put into a washing device to be washed and eliminate residual liquid ammonia, the ramie yarn is dried in a high-temperature steam box at a higher temperature, ammonia flows out, the internal stress of the fiber is eliminated, the steam in the high-temperature steam box can also keep the swelling degree of the fiber, and the swelling and retraction rate is reduced.

Description

Swelling method of ramie yarn

Technical Field

The invention relates to the technical field of ramie yarn performance research, in particular to a swelling method of ramie yarns.

Background

Because the single fiber length of the fibrilia is short, the later-stage textile processing can be realized only after the fibrilia is mostly made into technical fibers. However, the single fiber of the prepared technical fiber is short, so the tip of the fiber is exposed outside the yarn to form a defect, which affects the fabric hand feeling, and the fiber needs to be subjected to swelling treatment, so that the tip is expanded and weakened to bring about the itching feeling. The swelling treatment of the fiber is normally carried out by using caustic soda and liquid ammonia. The main differences between the caustic soda mercerization finishing and the liquid ammonia finishing of the fabric are as follows:

1. the fabric has higher dye uptake and stronger luster after mercerization and finishing by using white liquor, but has slightly poor dyeing uniformity. After liquid ammonia finishing, the dye-uptake rate during dyeing is not as high as that of alkali mercerization, and the gloss is not as good as that of alkali mercerization. But the cotton textile fabric finished by the liquid ammonia has good leveling property and soft luster.

2. The fabric treated by the liquid ammonia has good dimensional stability and less discoloration. The dimensional change is still small despite multiple washes.

3. The liquid ammonia finishing hardly damages the fibers, but can improve the abrasion resistance and tear strength. And the fibers are damaged slightly during mercerizing and finishing in white liquor, and the weight of the fibers is reduced by more than 10%.

4. Liquid ammonia treatment: when the fibre was handled through liquid ammonia, liquid ammonia can permeate inside the fibre fibril fast, unpacks apart the fibre intramolecular hydrogen bond, makes it begin even inflation from the core, and the cross-section is expanded into circularly by flat, and the chamber is through diminishing, and the surface is smooth. Because of the change of the fiber crystal structure, the internal stress is eliminated and the fiber is not twisted, thereby improving the tensile strength and the tearing strength. The hand feeling is kept good even after repeated washing. The liquid ammonia treatment does not damage the fiber, the puffing effect is uniform, the ammonia gas is easy to remove, the process is simple, and the energy is saved.

But the fiber is partially retracted along with the removal of ammonia after the traditional liquid ammonia treatment.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provide a method for swelling ramie yarn.

The technical scheme adopted by the invention for solving the technical problems is as follows: a method of swelling a ramie yarn, the method comprising the steps of:

step 1: putting ramie yarn into a closed container, and then putting liquid ammonia into the closed container to react the liquid ammonia with the ramie yarn;

step 2: taking out the reacted ramie yarn, and putting the ramie yarn into a high-temperature steam box to react so as to make ammonia flow out;

and step 3: and taking out the dried ramie yarn, and putting the ramie yarn into a washing device to clean and eliminate residual liquid ammonia.

Further, the temperature of the liquid ammonia in thestep 1 is-40 ℃.

Further, the reaction time of the liquid ammonia and the ramie yarn in thestep 1 is 30-60 s.

Further, the working temperature range of the high-temperature steam box in the step 2 is 90-120 ℃, and the humidity range is 70% -80%.

Further, the drying time of the ramie yarn in a high-temperature steam box is 8-15 min.

Furthermore, compared with untreated ramie yarn, the treated ramie yarn has the advantages that the fiber crystallinity is reduced by 14-20%, the wicking speed is improved by 20-25%, and the fiber expansion retention degree is improved by 14-25%.

Further, the ammonia content of the ramie yarn after high-temperature treatment and water washing is lower than 5%.

Further, the working temperature of the high-temperature steam box in the step 2 is 100 ℃.

Further, the weight ratio of the ramie yarn to the liquid ammonia in the step 2 is as follows: 1000:1.

Compared with the prior art, the invention has the following beneficial effects:

1. according to the method for swelling the ramie yarn, provided by the invention, the ramie yarn is dried at a higher temperature in a high-temperature steam box, so that ammonia gas flows out and the internal stress of the fiber is eliminated, the steam in the high-temperature steam box can also keep the swelling degree of the fiber, the swelling and retraction rate is reduced, meanwhile, the fiber is put into water to further eliminate residual liquid ammonia to be neutral, the ammonia gas remained in the fiber further flows out, and the process recovery rate and the product health and environmental friendliness are improved.

2. Compared with alkali mercerization, the swelling method for ramie yarn provided by the invention reduces 14% -20% of fiber crystallinity reduction after liquid ammonia treatment and high-temperature setting, improves hand feeling, increases 20% -25% of wicking speed, and reduces strength loss.

3. Compared with the traditional liquid ammonia treatment, the swelling method of the ramie yarn provided by the invention has the advantages that the fiber swelling retention degree is improved by about 14-25%, and the woven fabric has better softness.

Drawings

FIG. 1 is a diagram of the steps of the method of the present invention;

FIG. 2 is a graph comparing the high and low temperature treatment of the present invention to the shrinkage of a ramie yarn.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

As shown in fig. 1-2, the present invention provides a swelling method of a hemp yarn, comprising the steps of: step 1: putting ramie yarn into a closed container, and then putting liquid ammonia into the closed container to react the liquid ammonia with the ramie yarn; step 2: taking out the reacted ramie yarn, and putting the ramie yarn into a high-temperature steam box with the working temperature of 90 ℃ for reaction to enable ammonia gas to flow out, wherein the ramie yarn should be in a closed environment when being taken out, so that the liquid ammonia is ensured not to have leakage danger; and step 3: and taking out the dried ramie yarn, and putting the ramie yarn into a washing device to clean and eliminate residual liquid ammonia.

The temperature of the liquid ammonia in thestep 1 is-40 ℃, the reaction time of the liquid ammonia and the ramie yarn in thestep 1 is 30-60 s, the reaction time of the ramie yarn in a high-temperature steam box is 8-15min, the working humidity is 70-80%, compared with untreated ramie yarn, the fiber crystallinity of the treated ramie yarn is reduced by 14-20%, the speed is increased by 20-25%, the swelling retention degree of wicking fiber is increased by 14-25%, the ammonia content of the ramie yarn after high-temperature treatment and water washing is lower than 5%, and the weight ratio of the ramie yarn to the liquid ammonia in the step 2 is as follows: 1000:1, and the shrinkage of the ramie yarn processed by a high-temperature steam box at 90 ℃ is 3.8%.

Example 2

The invention provides a swelling method of ramie yarn, which comprises the following steps: step 1: putting ramie yarn into a closed container, and then adding liquid ammonia at-40 ℃ into the closed container to react the liquid ammonia and the ramie yarn for 30-60 s, wherein the weight ratio of the ramie yarn to the liquid ammonia is 1000: 1; step 2: taking out the reacted ramie yarn, and putting the ramie yarn into a high-temperature steam box with the working temperature of 100 ℃ and the working humidity of 70% -80% to react for 8-15min to make ammonia gas flow out, wherein the ramie yarn is taken out in a closed environment to ensure that the ammonia gas is not in danger of leakage; and step 3: and taking out the dried ramie yarn, and putting the ramie yarn into a washing device to clean and eliminate residual liquid ammonia. The shrinkage of the ramie yarn treated by the high-temperature steam box at 100 ℃ is 3.3%.

Example 3

The invention provides a swelling method of ramie yarn, which comprises the following steps: step 1: putting ramie yarn into a closed container, and then adding liquid ammonia at-40 ℃ into the closed container to react the liquid ammonia and the ramie yarn for 30-60 s, wherein the weight ratio of the ramie yarn to the liquid ammonia is 1000: 1; step 2: taking out the reacted ramie yarn, and putting the ramie yarn into a high-temperature steam box with the working temperature of 120 ℃ and the working humidity of 70% -80% to react for 8-15min to make ammonia gas flow out, wherein the ramie yarn is taken out in a closed environment to ensure that the ammonia gas is not in danger of leakage; and step 3: and taking out the dried ramie yarn, and putting the ramie yarn into a washing device to clean and eliminate residual liquid ammonia. The shrinkage of the ramie yarn treated by the 120-DEG C high-temperature steam box is 3.2%.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although the present invention has been described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (9)

1. A method for swelling a ramie yarn, the method comprising the steps of:

step 1: putting ramie yarn into a closed container, and then putting liquid ammonia into the closed container to react the liquid ammonia with the ramie yarn;

step 2: taking out the reacted ramie yarn, and putting the ramie yarn into a high-temperature steam box to react so as to make ammonia flow out;

and step 3: and taking out the dried ramie yarn, and putting the ramie yarn into a washing device to clean and eliminate residual liquid ammonia.

2. The method for swelling ramie yarn according to claim 1, wherein the liquid ammonia in step 1 has a temperature of-40 ℃.

3. The method for swelling ramie yarn according to claim 2, wherein the reaction time of the liquid ammonia with the ramie yarn in step 1 is 30s-60 s.

4. The method for swelling ramie yarn according to claim 3, wherein the operating temperature of the high-temperature steam box in the step 2 is in the range of 90-120 degrees, and the humidity is in the range of: 70 to 80 percent.

5. The method for swelling ramie yarn according to claim 4, wherein the reaction time of the ramie yarn in a high-temperature steam oven is 8-15 min.

6. The method of claim 5, wherein the treated ramie yarn has a fiber crystallinity reduction of 14% to 20%, a wicking rate increase of 20% to 25%, and a fiber swelling retention increase of about 14% to 25% as compared to untreated ramie yarn.

7. The method of swelling a ramie yarn according to claim 6, wherein the ammonia content of the ramie yarn after the high-temperature treatment and the water washing is less than 5%.

8. The method of claim 7, wherein the operating temperature of the high temperature steam box in step 2 is 100 ℃.

9. The method for swelling ramie yarn according to claim 8, wherein the weight ratio of the ramie yarn to the liquid ammonia in step 2 is: 1000:1.

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