CN121295365A - A method and apparatus for preparing regenerated cellulose industrial filaments - Google Patents

Abstract

The invention belongs to the technical field of regenerated cellulose industrial yarns, and particularly relates to a preparation method and a preparation device of regenerated cellulose industrial yarns. The regenerated cellulose industrial yarn is prepared by adopting a new solvent method, and the elongation at break and the dimensional stability of the industrial yarn can be obviously improved through gradient heat setting treatment. The heat setting area of the preparation device sequentially comprises a high temperature area and a low temperature area according to the passing sequence of the industrial yarn. The preparation method and the device of the regenerated cellulose industrial yarn have simple method and structure, can obviously improve the overall performance of the industrial yarn, and can be used for preparing tire products such as cord fabrics and the like.

Description

Preparation method and preparation device of regenerated cellulose industrial yarn

Technical Field

The invention belongs to the technical field of regenerated cellulose industrial yarns, and particularly relates to a preparation method and a preparation device of regenerated cellulose industrial yarns.

Background

The regenerated cellulose fiber is produced by using natural cellulose as raw material and only changing its physical structure without changing its chemical structure. Compared with synthetic fiber industrial yarn, the regenerated cellulose industrial yarn is derived from renewable natural resources, can be naturally degraded and is more environment-friendly.

In practical applications of regenerated cellulose industrial yarn, such as the application in the direction of cord yarn, the regenerated cellulose industrial yarn is required to have high strength (fiber consumption can be reduced under the same strength), and also required to have certain toughness, and can generate certain buffer action through deformation when being subjected to tensile force so as to improve fatigue resistance, and avoid hidden troubles such as broken cord yarn and even tire burst caused by abrupt concentration of stress exceeding a limit.

However, regenerated cellulose industry wire break strength and elongation at break often have a negative correlation. In the spinning process of the fiber, the higher the drawing multiplying power is applied, the more orderly the macromolecular chains are arranged along the axial direction of the fiber, the more bonding points such as hydrogen bonds among the molecular chains are, and the breaking strength is improved. However, the highly oriented and crystalline structure makes the movable range of the molecular segment smaller, and the ability to elastically deform decreases, so that the elongation at break decreases. How to improve the breaking elongation of regenerated cellulose industrial yarns while ensuring the breaking strength thereof is one of the technical difficulties in the art.

At present, the regenerated cellulose industrial yarn (cellulose filament) is mostly prepared by a new solvent method (dry-jet wet spinning forming process), the conventional heat setting process is hot roller drying, and the cellulose gel yarn bundles after drafting, water washing and oiling are wound on at most a pair of hot rollers to be dried, and then the yarn bundles are wound on a winding machine to be packaged after being dried. The filament bundle is heated to shrink during stoving, and the heat setting process is fixed length drying, so that the filament bundle can not shrink to increase the external tension and the stress inside the fiber is increased, and the molecular chains are aligned along the fiber axis direction to form compact crystal structure. Under such high tension drying conditions, the filaments have higher strength and modulus, and the molecular chains of the fibers are sufficiently stretched during drying, and are not easily elongated again when subjected to external force, resulting in a decrease in elongation at break.

Patent document CN118308795A discloses a method for preparing regenerated cellulose industrial yarn, which, although the mechanical properties of the industrial yarn are improved by adopting an improved air bath and stretching process, has low elongation at break. Patent document CN117535804a discloses a method and apparatus for producing regenerated cellulose industrial yarn, which improves the breaking elongation of the regenerated cellulose industrial yarn by improvements of coagulation bath and coagulation treatment.

However, the prior art has not made more intensive research and exploration on how to further optimize the process, improve the properties of regenerated cellulose industrial filaments in the heat setting process.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a method and an apparatus for producing regenerated cellulose industrial yarn. The scheme of the invention is as follows:

a preparation method of regenerated cellulose industrial yarn comprises the following steps of preparing cellulose spinning stock solution containing ionic liquid, spinning, solidifying and stretching, washing, oiling and heat setting, wherein in the heat setting step, yarn is firstly subjected to a high-temperature region and then is subjected to a low-temperature region, the setting temperature of the high-temperature region is 108-160 ℃, the tension is 0.02 cN/dtex-0.6 cN/dtex, the setting time is 5-40 s, and the setting temperature of the low-temperature region is 50-102 ℃, the tension is 0.02 cN/dtex-0.6 cN/dtex, and the setting time is 10-120 s.

Preferably, the cellulose spinning solution is prepared from cellulose pulp with a polymerization degree of 400-1400 and ionic liquid, wherein the mass fraction of the cellulose pulp in the cellulose spinning solution is 4% -18%.

Preferably, the ionic liquid is selected from one or more of 1-butyl-3-methylimidazole chloride salt, 1-allyl-3-methylimidazole chloride salt, 1-ethyl-3-methylimidazole acetate, 1-ethyl-3-methylimidazole chloride salt or 1-butyl-3-methylimidazole acetate.

Preferably, the solidifying and stretching steps comprise three-stage gradient solidifying and stretching steps, wherein the first-stage solidifying bath adopts an ionic liquid aqueous solution with the mass fraction of 35% -60%, the temperature is 0 ℃ -30 ℃, the stretching multiplying power is 1-5 times, the stretching speed is 10 m/min-150 m/min, the second-stage solidifying bath adopts an ionic liquid aqueous solution with the mass fraction of 20% -30%, the temperature is 10 ℃ -90 ℃, the stretching multiplying power is 0.9-1.2 times, the stretching speed is 9 m/min-180 m/min, the third-stage solidifying bath adopts an ionic liquid aqueous solution with the mass fraction of 5% -19%, the temperature is 10 ℃ -90 ℃, the stretching multiplying power is 0.9-1.2 times, and the stretching speed is 8-200 m/min.

Preferably, the silk strip in the solidification and stretching steps passes through an air section and then enters a solidification bath, and the length of the air section is 10 mm-400 mm.

Preferably, the spinning step has spinning holes with the number of 100-3000 holes, the diameter of 40-200 μm and the spinning temperature of 80-120 ℃.

Preferably, in the oiling step, the oiling temperature of the yarn is 30-50 ℃, and the oiling rate of the yarn is 0.1-0.5%.

The invention further provides a regenerated cellulose industrial yarn preparation device suitable for the method, which comprises a yarn spraying assembly, a blowing device, a solidification zone, a washing zone, a drafting device, an oiling zone, a heat setting zone, a tension roller and a winding machine, wherein the heat setting zone sequentially comprises a high-temperature zone and a low-temperature zone according to the passing sequence of yarn.

Preferably, the heating device adopted in the heat setting area is an oven.

Advantageous effects

The invention improves the heat setting technology and the structure of the heat setting area, thereby improving the performance of regenerated cellulose industrial yarns. When the method is used in combination with the existing new solvent method regenerated cellulose industrial yarn improved preparation process (such as staged water washing and/or staged solidification/stretching), the elongation at break of the regenerated cellulose industrial yarn can be further improved remarkably, the influence on the breaking strength is small, and the dimensional stability of the product is improved remarkably. Therefore, the mechanical properties of the prepared regenerated cellulose industrial yarn are more in line with the high elongation at break and strength requirements of products such as tire cord fabrics and the like, and the regenerated cellulose industrial yarn has the advantage of dimensional stability.

In the heat setting process, the first stage heat treatment is set at a relatively high temperature, and the second stage heat treatment is set at a slightly lower temperature than the first stage, so that the combination of the two ensures that the regenerated cellulose fibers shrink sufficiently and are dried and set while the moisture is removed. Thereby realizing the effect of further obviously improving the comprehensive performance of the regenerated cellulose industrial yarn in the heat setting process.

Drawings

FIG. 1 is a schematic view of an apparatus used in the preparation of regenerated cellulose industrial yarn according to the present invention;

in the figure, 1 is a spinning assembly; 2 is a blowing device, 3 is a solidification zone, 4 is a washing zone, 5 is a drafting device, 6 is an oiling zone, 7 is a heat setting zone, 8 is a tension roller, and 9 is a winding machine.

Detailed Description

The following further describes the aspects and effects of the present invention in connection with the detailed description. It is to be understood that these examples are merely illustrative of the embodiments and effects of the present invention and are not intended to limit the scope of the present invention. Various changes and modifications to the present invention may be made by one skilled in the art without undue burden, and such equivalents/equivalent variations are within the scope of the present invention.

In order to ensure comparability, the oiling agent used in the following examples and comparative examples is DELION FA-4042 oiling agent for cellulose industrial yarn provided by Japanese bamboo Co., ltd, and the ionic liquids used in the different steps of the same sample preparation process are the same.

Example 1 preparation apparatus for regenerated cellulose Industrial yarn

This example provides an apparatus for the preparation of regenerated cellulose industrial yarn according to the present invention, the schematic structure of which is shown in FIG. 1. The device consists of a spinning assembly 1, a blowing device 2, a coagulation zone 3, a washing zone 4, a drafting device 5, an oiling zone 6, a heat setting zone 7, a tension roller 8 and a winding machine 9. Wherein the arrow represents the direction of advance of the material/wire.

Compared with the prior art, the device is mainly characterized in that the heat setting area 7 is divided into two sections, and the yarn sequentially passes through two sections of a high temperature area (high temperature heat setting area) and a low temperature area (low temperature heat setting area) when the process is carried out. The heating means of the heat-setting zone may be an oven (providing the required stabilization temperature for heat-setting) commonly used in the art, through which different heat-setting temperatures are provided.

Wherein the spinning pack 1, the blowing device 2, the coagulation zone 3, the washing zone 4, the drawing device 5, the oiling zone 6, the tension roller 8 and the winder 9 can be all devices of the prior art.

In the production process, after the spinning solution passes through the spinning assembly 1, the temperature is reduced by means of a blowing device 2 (a conventional circular blowing device can be adopted), then coagulation bath is carried out in a coagulation zone 3, water washing is carried out in a water washing zone 4, oiling is carried out in an oiling zone 6, and zonal heat setting is carried out in a heat setting zone 7. The drafting device 5, the tension roller 8 and the winding machine 9 provide traction and power for the yarn advancing, wherein the tension roller 8 can adjust the tension.

Example 2 regenerated cellulose Industrial yarn and Process for preparing the same

This example provides several regenerated cellulose industrial filaments prepared according to the present invention and a process for preparing the same, comprising the steps of (wherein the different experimental examples have the different process parameters as shown in table 1):

s1, preparing cellulose spinning solution

Mixing cellulose pulp with 80% ionic liquid aqueous solution by mass fraction, dehydrating and dissolving to prepare cellulose spinning solution.

S2 spinning

The prepared cellulose spinning dope was extruded through a spinneret (see spinneret pack 1 of example 1), the number of the spinneret holes was 1000, the diameter of the spinneret holes was 70 μm, and the spinning temperature was 105 ℃.

(3) Solidification and stretching

The extruded strand was passed through an air section (see blowing device 2 of example 1) and into a coagulation bath (see coagulation zone 3 of example 1), the length of the air section was 50mm, the coagulation and stretching involved three-stage gradient coagulation, the first stage coagulation bath was an aqueous ionic liquid solution having a mass fraction of 40%, the temperature was 15 ℃, the stretching magnification was 1.5 times, the stretching speed was 20 m/min, the second stage coagulation bath was an aqueous ionic liquid solution having a mass fraction of 25%, the temperature was 80 ℃, the stretching magnification was 0.97 times, the stretching speed was 19.4 m/min, the third stage coagulation bath was an aqueous ionic liquid solution having a mass fraction of 15%, the temperature was 80 ℃, the stretching magnification was 0.99 times, and the stretching speed was 19.2 m/min.

(4) Washing with water

The filaments from the coagulation bath were subjected to water bath for water washing (see water washing zone 4 of example 1).

(5) Oiling

The strands exiting the water wash zone were then passed through the oiling zone (see oiling zone 6 of example 1) for oiling. The oiling temperature is 40 ℃ and the oiling rate of the yarn is 0.3%.

(6) Heat setting

The water-washed and oiled silk strip enters a heat setting zone (see the heat setting zone 7 of the example 1) and is subjected to a heat treatment process to obtain regenerated cellulose industrial silk.

Table 1 different experimental examples of different process parameters

The remarks "wt" indicate that the concentration is the mass percent concentration (i.e., mass fraction of cellulose pulp in the solution).

Example 3 comparison of the Properties of different regenerated cellulose Industrial filaments

This example provides a part of the exploration during the study (i.e., the comparative example) and provides performance test results for different samples.

The regenerated cellulose industrial yarn preparation method of comparative example 1 is shown in experimental example 1 of example 2, and differs from experimental example 1 only in that in the heat setting of step (6), the heat setting process of the prior art is adopted. The heat treatment is carried out by a hot roller, the heat treatment time of the filament is controlled by the number of the hot roller pairs, the temperature of the hot roller (namely the heat setting temperature) is 100 ℃, and the residence time of the hot roller (namely the heat setting time) is 46s.

The regenerated cellulose industrial yarn preparation method of comparative example 2 is shown in experimental example 2 of example 2, and differs from experimental example 2 only in that the heat setting process of the prior art is adopted in the heat setting of step (6). The heat treatment is carried out by a hot roller, the heat treatment time of the filament is controlled by the number of the hot roller pairs, the temperature of the hot roller (namely the heat setting temperature) is 100 ℃, and the residence time of the hot roller (namely the heat setting time) is 46s.

The samples of experimental examples 1 to 4 of example 2 and comparative examples 1 and 2 of this example were subjected to performance tests, wherein the fineness measurement was referred to national standard GBT14343-2008 "chemical fiber-filament linear density test method", breaking strength test was referred to GBT14344-2008 "chemical fiber-filament tensile property test method", elongation at break was referred to GBT14344-2008 "chemical fiber-filament tensile property test method", and dry heat shrinkage test was referred to GBT6505-2008 "chemical fiber-filament heat shrinkage test method". The test results are shown in Table 2.

TABLE 2 results of measurement of the Properties of different regenerated cellulose Industrial filaments

As can be seen from Table 2, compared with the industrial yarn obtained by the traditional heat setting process, the regenerated cellulose industrial yarn has extremely small reduction of breaking strength, belongs to the conventional fluctuation range of the industrial yarn performance parameters, and has obviously improved breaking elongation. In addition, the dry heat shrinkage is an index for evaluating the dimensional stability of fibers, and is particularly important for regenerated cellulose industrial yarns. As can be seen from table 2, the regenerated cellulose industrial yarn prepared by the heat setting process of the present invention has a significantly lower dry heat shrinkage than the industrial yarn obtained by the conventional heat setting process, and the dimensional stability is unexpectedly improved.

Claims (9)

1. A preparation method of regenerated cellulose industrial yarn comprises the following steps of preparing cellulose spinning stock solution containing ionic liquid, spinning, solidifying and stretching, washing, oiling and heat setting, and is characterized in that in the heat setting step, yarn is firstly subjected to a high-temperature region and then is subjected to a low-temperature region, the setting temperature of the high-temperature region is 108-160 ℃, the tension is 0.02 cN/dtex-0.6 cN/dtex, the setting time is 5-40 s, the setting temperature of the low-temperature region is 50-102 ℃, the tension is 0.02 cN/dtex-0.6 cN/dtex, and the setting time is 10-120 s.

2. The preparation method of the regenerated cellulose industrial yarn according to claim 1, wherein the cellulose spinning solution is prepared from cellulose pulp with a polymerization degree of 400-1400 and an ionic liquid, and the mass fraction of the cellulose pulp in the cellulose spinning solution is 4% -18%.

3. The method for preparing regenerated cellulose industrial yarn according to claim 1, wherein the ionic liquid is selected from one or more of 1-butyl-3-methylimidazole chloride salt, 1-allyl-3-methylimidazole chloride salt, 1-ethyl-3-methylimidazole acetate, 1-ethyl-3-methylimidazole chloride salt or 1-butyl-3-methylimidazole acetate.

4. The preparation method of the regenerated cellulose industrial yarn according to claim 1 is characterized in that the solidification and stretching step comprises three-stage gradient solidification and stretching steps, wherein a first-stage solidification bath adopts an ionic liquid aqueous solution with the mass fraction of 35% -60%, the temperature is 0 ℃ -30 ℃, the stretching rate is 1-5 times, the stretching speed is 10-150 m/min, a second-stage solidification bath adopts an ionic liquid aqueous solution with the mass fraction of 20% -30%, the temperature is 10 ℃ -90 ℃, the stretching rate is 0.9-1.2 times, the stretching speed is 9-180 m/min, a third-stage solidification bath adopts an ionic liquid aqueous solution with the mass fraction of 5% -19%, the temperature is 10 ℃ -90 ℃, the stretching rate is 0.9-1.2 times, and the stretching speed is 8-200 m/min.

5. The method for preparing regenerated cellulose industrial yarn according to claim 1, wherein the yarn in the solidifying and stretching steps passes through an air section and then enters a solidifying bath, and the length of the air section is 10 mm-400 mm.

6. The method for preparing regenerated cellulose industrial yarn according to claim 1, wherein the spinning step has a spinning hole number of 100-3000 holes, a spinning hole diameter of 40-200 μm and a spinning temperature of 80-120 ℃.

7. The method for producing regenerated cellulose industrial yarn according to claim 1, wherein in the oiling step, the oiling temperature of the yarn is 30 ℃ to 50 ℃, and the oiling rate of the yarn is 0.1% -0.5%.

8. A regenerated cellulose industrial yarn preparation device for the preparation method of the regenerated cellulose industrial yarn according to any one of claims 1 to 7, comprising a yarn spraying assembly, a blowing device, a solidification zone, a washing zone, a drafting device, an oiling zone, a heat setting zone, a tension roller and a winding machine, wherein the heat setting zone sequentially comprises a high temperature zone and a low temperature zone according to the passing sequence of yarn.

9. The apparatus for producing regenerated cellulose industrial filament according to claim 8, wherein the heating means used in the heat setting section is an oven.