WO2016188274A1

WO2016188274A1 - Matte high-strength, low-stretch viscose fiber and manufacturing method therefor

Info

Publication number: WO2016188274A1
Application number: PCT/CN2016/079847
Authority: WO
Inventors: 冯涛; 邓传东; 李蓉玲; 贺敏; 黄艺; 陈明付; 刘爱兵
Original assignee: 宜宾丝丽雅集团有限公司; 宜宾丝丽雅股份有限公司; 宜宾海丝特纤维有限责任公司
Priority date: 2015-05-27
Filing date: 2016-04-21
Publication date: 2016-12-01
Also published as: CN104846459A

Abstract

The present invention relates to the technical field of textile fiber processing. Disclosed is a matte high-strength, low-stretch viscose fiber. he viscose fiber is produced from a pulp raw material that sequentially undergoes impregnation, grinding, pressing and crushing, rubbing, degradation, xanthation, dissolution, filtration, defoaming, aging, spinning and drafting, and aftertreatment. The viscose fiber of the present invention has the following technical indicators: dry tensile strength ≥ 3.10 cN/dtex, wet tensile strength ≥ 1.60 cN/dtex, strength required to produce 5% elongation in a wet state ≥ 0.55 cN/dtex, dry breaking elongation 11.0-19.0%, wet breaking elongation 16.0-21.0%, radial water swelling capacity 22-26%, and matting agent content 0.8-5%. The viscose fiber of the present invention is a novel viscose fiber and has lower production costs compared with an existing modal, thus providing great economic and social benefits.

Description

Matting type high strength low elongation viscose fiber and preparation method thereof

Technical field

The invention relates to viscose fiber and preparation thereof, in particular to a matting type high-strength low-stretch viscose fiber and a preparation method thereof, and belongs to the technical field of textile fiber processing.

Background technique

At present, textile fiber raw materials are mainly classified into natural fiber raw materials represented by cotton and hemp, petroleum-based fiber raw materials represented by polyester and acrylic fibers, and bio-based materials such as viscose fiber which is regenerated from natural cellulose materials. Fiber raw materials. At present, with the scarcity of land resources and the shortage of human resources, the cotton planting area is declining year by year, and cotton products will not meet the growing needs of people's living standards. With the decreasing oil reserves and people's comfort for textiles, Functional and environmentally conscious awareness continues to increase, and viscose fibers produced from renewable resources are increasingly valued. As viscose fiber, as a natural recycled fiber, it has both natural fiber quality and excellent processability. Its structural composition is similar to that of cotton. It has high hygroscopicity, good gas permeability, comfortable wearing and easy dyeing. High temperature resistance and other characteristics, at the same time, it has the drape and softness that cotton does not have. Of course, due to these excellent properties of viscose fiber, it has developed very rapidly in recent years, especially the viscose fiber of common varieties. The scale is exploding rapidly. This phenomenon has caused a tight supply of raw materials and fierce competition in the market. At the same time, it has restricted the development of new downstream textiles and industrial upgrading.

Based on the above situation, in order to promote the sustainable development of the viscose fiber industry, the production of differentiated and functional viscose fiber has become a new standard in the industry. Patent document CN102296373A (a method for producing ultra-fine high-strength high-mode viscose fiber, 2011.12.28) discloses a viscose fiber having a uniform structure, a fiber strength and a modulus higher than that of a conventional variety of 50% or more. The viscose fiber has a fiber strength of 0.44 to 0.78 dtex, a dry strength of ≥3.1 cN/dtex (centimeter/denier), a wet strength of ≥2.1 cN/dtex, a wet modulus of ≥0.5 cN/dtex, and a whiteness of ≥82.0%. .

Patent document CN1632189 (a high-white strong fine-density viscose staple fiber and its production process, 2005.06.29) discloses a fine-density, high-strength viscose staple fiber, which is processed by an ordinary viscose fiber. In terms of high strength, strong abrasion resistance, fine hand feeling, anti-pleatability, resistance to multiple deformations, etc., it can also be used for textile high count yarn woven products.

Patent document CN102251301A (a superfine denier high-strength viscose fiber production process, 2011.11.23) discloses a preparation method of viscose fiber with low fineness and high strength, which can obtain a fineness of 1.11 dtex and a strength of more than 2.9 cN/ Dtex viscose fiber.

It is only known from the above-disclosed patent documents that in order to produce differentiated, functionalized viscose fibers, the prior art is achieved by changing the production process, in which raw materials, viscose molding and process parameters are involved. The change of viscose fiber is better optimized in terms of fineness and strength than ordinary viscose fiber, but for the increasingly fierce market competition, the differentiated viscose fiber does not meet the downstream limit to a greater extent. The development of new textiles and industrial upgrading, especially the development of fiber materials such as Tencel, Modal, and Cuminous fiber, which are also recycled from natural cellulose materials, have led to a decline in the market share of viscose fibers. For example, the patent document CN101130885 (the preparation method of the sesame viscose fiber and the prepared sesame viscose fiber, 2008.02.27) discloses a viscose fiber produced by using a hemp material plant and a preparation process thereof, and the process is simple and the material consumption is Low, and the produced ramie viscose fiber has excellent whiteness, strength and fiber elongation. The ramie viscose fiber prepared by the process meets the dry rupture strength ≥1.820cN/dtex, and the wet rupture strength ≥1.12 cN/dtex, dry elongation at break ≥15.4%, linear density deviation rate ±6.00%, length deviation rate ±6.00%, ultra-long fiber rate ≤1.0%, long fiber ≤18.0mg/100g, defect point ≤11mg/100g , residual sulfur ≤ 18.0mg / 100g.

Taking Modal fiber as an example, we know that Modal fiber is made from European eucalyptus wood and made into a wood slurry and then made by a special spinning process. It is the same natural fiber material as cotton, and the modal fiber is not produced in the whole production process. Any pollution, its dry strength is close to polyester, the wet strength is much higher than ordinary viscose fiber, no matter the gloss, softness, hygroscopicity, dyeing, dyeing fastness is better than pure cotton products, use it to do The finished fabric not only exhibits a silky luster, but also has a pleasant soft touch feeling and drape, as well as excellent wear resistance. It is an ideal environmentally friendly cellulose fiber. However, due to the high cost of modal fiber textile technology, the market modal modal is basically a blend of modal and cotton, or directly take the viscose (human cotton) fiber to impersonate Modal.

To this end, we need to find a new viscose fiber that is different from natural fiber raw materials and petroleum-based fiber raw materials and has better performance than differentiated viscose fiber, which not only meets the requirements of natural products (such as modal fiber). It can also be applied to the continuous production of industrialization, bringing greater economic benefits to the enterprise. Of course, this is also an inevitable trend for the viscose fiber industry to continue to develop.

Summary of the invention

The object of the present invention is to provide a matting type high-strength low-stretch viscose fiber which is different from the traditional viscose fiber product and cotton fiber, and is a novel fiber type realized by technological innovation, which is different from ordinary viscose. The index system of fiber and modal fiber not only exhibits the high-strength, low-stretch fiber characteristics of modal fiber, but also exhibits better skin-friendly properties than cotton fiber and modal, and can effectively replace existing modal fiber, and Production costs are lower than Modal and have good economic and social benefits.

The invention is realized by the following technical scheme: a matting type high-strength low-stretch viscose fiber, which is a slurry raw material which is sequentially impregnated, ground, pressed, crushed, smashed, depolymerized, yellowed, dissolved, filtered, taken off. After the foaming, aging, spinning drafting and post-treatment, the matting type high-strength low-stretch viscose fiber meets the following technical indexes:

Dry breaking strength ≥ 3.10cN/dtex;

Wet breaking strength ≥ 1.60cN / dtex;

The strength required to produce 5% elongation in wet state is ≥0.55 cN/dtex,

Dry elongation at break is 11.0 to 19.0%;

Wet elongation at break is 16.0 to 21.0%;

Radial water swelling degree 22 to 26%;

Crystallinity 40.0 to 45.0%;

The matting agent content is 0.8 to 5%.

The pulp raw material comprises one or a combination of two or more of cotton pulp, bamboo pulp, wood pulp and hemp pulp. In practical application, cotton pulp, bamboo pulp, wood pulp and hemp pulp can be carried out in any ratio. Mixing, wide source of raw materials, and low requirements on the content of fiber, can effectively reduce the cost of raw materials.

The degree of polymerization of the pulp raw material is 650 to 1200, and the advantage is that the length of the softwood pulp fiber is 2 to 3 mm, and the strength is higher.

Further preferably, the viscose fiber further satisfies the following technical indicators:

Whiteness ≥ 85%;

Linear density deviation rate ≤ ± 11.0%;

Residual sulfur ≤ 12.0mg / 100g;

Length deviation rate ≤ ± 11.0%;

Ultra-long fiber rate ≤0.5%;

Double fiber ≤4.0mg/100g;

The defect point is ≤4.0mg/100g.

Another object of the present invention is to provide a method for preparing a matting type high-strength low-stretch viscose fiber, which comprises pulp as a raw material for production, viscose fiber by viscose preparation, spinning process and post-treatment, During the production process, the cross-sectional area of the secondary reaction microscope is still retained, and the ratio of the inner and outer layers of the interface is significantly different from the secondary reaction traces of the modal fiber and the ordinary viscose fiber, ensuring that the product has the characteristics of high strength and low elongation. It also has suitable water absorption and significant fiber skin-friendly properties.

The specific steps of the preparation method of the matting type high-strength low-stretch viscose fiber are as follows:

A. The pulp raw material is immersed in a dipping bucket containing alkali solution, and ground by a grinder to prepare a slurry of porridge having a concentration of 3 to 6%. In actual production, the pulp raw material is first placed on the feeder. After setting a certain feeding speed (such as 40kg/min), it is added to the dip tank, and the purpose of the grinding is to open and disperse the fiber by mechanical action, thereby increasing the alkalization speed and alkalization rate of the cellulose;

B. The porridge obtained in the step A is sent to a press, and after being pressed, it is sent to a pulverizer for pulverization to obtain alkali cellulose, and the alkali cellulose is sent to a crucible, and the concentration is 30-40% after treatment. Pulp porridge, in this step, the press can remove excess lye, and the excess lye can be recycled. The treatment method is to remove the lye by using a filter with a filter of 60-120 mesh and a vacuum of -0.4 to -0.1 MPa. After the excess hemicellulose is recovered, the alkali cellulose is recovered, and the twin-screw equipment is used to make the fiber separate and smelt, thereby breaking the cell wall of the cellulose fiber, removing small molecules in the cellulose, thereby improving the cellulose reaction performance. , to increase the content of cellulose-bound alkali, reaching 6 to 8% (mass percentage);

C. The porridge obtained in the step B is mixed with the lye and sent to the reactor, and pure oxygen is added to the reactor to obtain an alkali fiber having a degree of polymerization of 400-600 and a purity of 98.0-98.5%. In this step, the purpose of adding pure oxygen is oxidative depolymerization. After depolymerization, the degree of polymerization of alkali cellulose is reduced from 650 to 1200 to 400 to 600.

D. The alkali cellulose obtained in step C is sent to a yellowing machine, carbon disulfide is added to the yellowing machine, and after the yellowing reaction, the cellulose sulfonate obtained by the yellowing reaction is dissolved in a solvent to obtain a concentration of 9.0 to 10.0% cellulose sulfonate solution;

E. After filtering, defoaming and aging the cellulose sulfonate solution prepared in step D, a matting agent is added to obtain a spinning dope, and the obtained spinning dope is subjected to spinning drafting and post-treatment to obtain a viscose. fiber.

In the above step A, the lye is a sodium hydroxide solution having a concentration of 110 to 240 g/L, the temperature of the immersion alkali solution is 30 to 60 ° C, and the immersion time is 50 to 90 minutes. In actual use, if the concentration of lye is too high, the solubility of the obtained cellulose sulfonate will decrease, and the viscosity of the viscose will be difficult to filter; the concentration of the alkali solution is too low, the degree of expansion of the pulp material is too high, and the pressing is difficult; the temperature is too high, and the cellulose is lowered. Gather quickly, accelerate side reactions, affect viscose filtration; temperature is too low, pulp pulping is high, and pressing is difficult.

In order to better implement the present invention, in the step A described, the grinder is disposed in a pipe connecting the dip tank and the press.

In order to achieve a better alkalization rate, in the step A, the temperature of the porridge is 30 to 60 ° C, and the grinding time of the mill is 10 to 40 s.

In the field of preparation of viscose fiber, the material pressed by the press by the press can be divided into two parts, one part is an excess alkali solution mixed with fibers and impurities, and the other part is a mixture of solid and liquid which is pressed out of excess water. That is, alkali cellulose, in the above step B, the press has a press temperature of 57 to 63 ° C and a press ratio of 2.2 to 2.8.

Pressing is to impregnate the pulp with excess lye, hemicellulose and impurities to increase the purity of the alkali cellulose. The degree of pressing is the pressure after pressing with the pulp and the quality of the pulp and the quality of the pre-impregnated dry pulp and quality. The ratio indicates that the pressed alkali cellulose is very tight, the plate is hard, and the surface area is small, which is not conducive to the later processing. The purpose of the pulverization is to make the alkali cellulose into fine and loose scraps, which increases the surface area and is beneficial to the later stage. The uniformity of the process and the expression of the degree of pulverization, which is a fixed weight of alkali cellulose, is simply referred to as the degree of pulverization in the present invention, and refers to the weight per unit volume after pulverization of alkali cellulose, generally expressed in g/L, and alkali. The better the cellulose pulverization effect, the smaller the fixed weight and the larger the surface area. Big.

In the step B, the porridge is pressed and sent to a pulverizer for pulverization. The pulverization degree of the pulverizer is 120-180 g/L, and the post-processing can be improved by adjusting the pressing ratio and the pulverization degree. The uniformity of the performance of the alkali cellulose in the process prevents the local from receiving strong extrusion, thereby hindering the entry of oxygen and reducing the speed of the depolymerization step; the content of the alkali fiber obtained by the pulverization is 29 to 31%, and the alkali content It is 15 to 17%, and the content of the half fiber in the lye is controlled within 10 g/L.

Further, in the step C, the lye is a sodium hydroxide solution having a concentration of 140 to 200 g/l, and the pure oxygen is added in an amount of 2 to 10% of the reactor volume, and the depolymerization reaction time is controlled at 30. ~60min.

In the step D, the amount of carbon disulfide added is 25 to 37% of the content of the methyl cellulose in the alkali cellulose obtained in the step B. In practical application, the amount of carbon disulfide added is too small, the yellowing reaction is incomplete, and the filtration is difficult. The amount of carbon disulfide added is too high, the yellowing reaction is excessive, and the by-products are more.

Further, in the step D, the yellowing reaction time is controlled at 45 to 50 minutes, and the yellowing reaction temperature is 20 to 30 °C.

Further, in the step D, the dissolving is mixing, stirring and grinding the cellulose sulfonate with a solvent, the solvent comprises a sodium hydroxide solution having a concentration of 25 to 45 g/L, and the concentration is 5-10 g/L aqueous sodium sulfite solution.

In the step D described, the dissolution temperature is 10 to 20 ° C, and the dissolution time is 30 to 50 minutes.

In the step D described, the matting agent is titanium dioxide.

In order to further improve the product characteristics of the viscose fiber, the present invention also improves the spinning drafting process, including a low acid and high salt moderate acid bath process and a high stretch spinning process, etc., specifically, the spinning The wire drawing steps are as follows:

F: the cellulose sulfonate solution is filtered, defoamed, and matured, and then sent to a spinning machine, which is extruded from a nozzle of a spinning machine and passed through a bath to form a tow, and the one bath is solidified. The bath comprises 90-120 g/L of sulfuric acid, 220-280 g/L of sodium sulfate and 8-15 g/L of zinc sulfate;

G: The tow after one bath is fed into the two bath by a drafting machine, the coagulation bath used in the two baths comprises 18-22 g/L of sulfuric acid, and the drafting ratio of the one drafting machine is 50-100. %;

H: The tow after the two baths is fed into the three baths by a two-way drafting machine, and the coagulation bath used in the three baths includes sulfuric acid having a pH of 1 to 3, and the draft ratio of the two drafting machines is 40 to 60%;

I: The tow after three baths was sent to the after-treatment portion by a three-way drafting machine, and the draft ratio of the three-way drafting machine was 5 to 15%.

As described above, the present invention adopts the three-bath wet spinning technique, and the viscose is formed into a tow after the spinning and drawing process, thereby ensuring multiple reactions of the fiber, in which the fiber cross section can form a clear secondary reaction. The microscope interface has the characteristics of improving the fiber strength, increasing the water absorption rate of the fiber, and increasing the water retention property of the fiber. In the spinning process, the tow is stretched by a drafting machine, a two-way drafting machine, and a three-way drafting machine. It is more conducive to improving the brittleness of the fiber and improving the elongation of the fiber.

The post-treatment includes desulfurization, bleaching and oiling of the tow formed by the spinning draft, and the desulfurizing agent used in the desulfurization is composed of sodium sulfide having a concentration of 4 to 8 g/L and a concentration of 1 to 4 g/L. The sodium carbonate composition; the bleaching agent used for the bleaching is a hydrogen peroxide concentration of 0.3-0.6 g/L; the oiling agent used for the oiling is 7-9 g/L, and the pH of the tow after oiling is 6.5. ~7.

The invention adopts a mild desulfurization process to reduce the damage of product strength and elongation. In actual use, the desulfurizing agent composed of sodium sulfide and sodium carbonate is milder than the existing sodium hydroxide and sodium sulfite, and the sodium carbonate can be used. And the sulfuric acid brought by the tow from the acid bath, after the desulfurization process, the pH of the adjustable tow is 8-11; the hydrogen peroxide bleach is milder than the bleach such as sodium hypochlorite, and the pH of the viscose fiber prepared by the invention should be The control is in the range of 6.5 to 7, and the pH value can also be adjusted by means of water washing and polyfunctional acid (organic acid). Within this range, the strength of the finished viscose fiber is not affected, and the elongation is high.

Further, the desulfurization temperature is 50 to 55 ° C, the desulfurization time is 2 to 3 min; the bleaching temperature is 50 to 55 ° C, the bleaching time is 1 to 2 min; and the temperature of the oil agent is 50 to 55 ° C. .

In the present invention, the post-treatment further includes drying, the drying is performed on the tow formed by the spinning draft, the desulfurization, bleaching and the tow obtained after the oiling are dried using a dryer. The drying temperature is 75-115 ° C. After drying, high-strength low-stretch viscose fiber products are obtained, and the moisture regain rate of the product is controlled at 11 to 13.5%.

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

(1) The viscose fiber according to the present invention is a novel fiber type realized through technological innovation, and belongs to a major innovation in the production technology of viscose staple fiber and cellulose fiber, which is different from the traditional viscose fiber product and Cotton fiber, which has an index system different from ordinary viscose fiber and modal fiber, has a fiber strength of 3.1 cN/dtex or more, which is about 30% higher than that of ordinary bio-based short fiber, close to modal, and has high strength of modal fiber. Low elongation and degradable characteristics make the fabric not easy to be deformed. It also has better moisture absorption and gas permeability than cotton fiber and modal, and it is soft, smooth and bright in appearance, and can effectively replace the existing differential viscosity. Glue fiber can improve the downstream processing performance of viscose fiber, and promote the development and industrial upgrading of downstream new textiles, with good economic and social benefits.

(2) The viscose fiber of the present invention has lower cost than the modal with higher performance index, and the price is lower than the modal fiber by 4000-5000 yuan/ton, and the viscose fiber of the invention is mainly reduced in the following aspects. Production cost: a. The raw material of the viscose fiber of the invention has wide source and low requirement, and the raw material with lower content of methyl cellulose can be selected (the higher the content of methyl cellulose, the higher the price), the cotton pulp, bamboo pulp, One or a combination of two or more of wood pulp and hemp pulp, no proportion requirement; b. the amount of alkali used in the process of the invention is lower than that of conventional products; c. during the spinning process in the process step of the present invention, The spinning speed of the spinning machine is 45-55m/min, which is faster than 30m/min in the production process of Modal. The optimized acid bath composition and drafting process can comprehensively balance the control of each process parameter, and the production efficiency is high. Low energy consumption, which reduces production costs.

(3) The invention adopts the three-bath wet spinning technology, the coagulation bath adopts low acid and high salt, the reaction condition is mild, and the viscose is formed into a tow after the spinning and drawing process, thereby ensuring multiple reactions of the fiber. The viscose fiber of the present invention has a secondary reaction interface different from that of ordinary viscose fiber and modal fiber. It should be noted that the secondary reaction interface is formed according to the difference in fiber dyeing ability of the fiber cross section, that is, the cortex of the fiber and The core layer and the skin layer have small color absorption ability and dyeing, and the core layer has a large color absorption ability for the dye, the color is deep, and the skin layer has a high degree of orientation. The more the skin layer, the higher the breaking strength, and the more the core layer The water swelling degree is higher; the fiber of the present invention is dyed and then subjected to fiber slicing, and the fiber slice of the viscose fiber according to the present invention exhibits a clear and obvious cross-sectional area of the secondary reaction microscope, and the "area" of the core layer and the skin layer. The ratio is (40-70): (30-60), the ratio is moderate, and the ratio of the "area" of the core layer and the cortex of ordinary viscose fiber is (90-95): (5-10), the ratio is biased to the inner layer, so Viscose fiber and ordinary viscose fiber of the invention Compared with high strength and low elongation, it also has proper water absorption, and fiber skin-friendliness has obvious advantages. After modal fiber dyeing, it is made into fiber section, observed under microscope, no secondary reaction interface, and the adhesive of the invention The fiber and the modal fiber under the same dyeing condition, the viscose fiber of the invention has a darker color absorption than the modal, the dyeing rate is higher, the uniformity is better, and the color fastness of the finished product is good.

(4) In order to ensure a suitable skin layer and core layer ratio at the secondary reaction interface of the high-strength and low-stretch viscose fiber, the present invention proceeds from the process technology to improve the acid bath process, such as reducing the sulfuric acid concentration, slow reaction, and increasing the thickness of the skin layer; The viscose index, such as viscose ripeness, nail fiber content, alkali content and the like, are changed to ensure high breaking strength of the viscose fiber of the present invention.

(5) Compared with the prior art viscose process, the alkali cellulose hemicellulose content obtained by the invention is low, and is controlled within 10 g/L. We know that hemicellulose refers to a polymerization degree of 50-200. β cellulose and γ cellulose with a degree of polymerization <50, the effect of hemicellulose is as follows: a. affecting the uniformity of alkali cellulose; b. prolonging the age of the old; c. yellowing of hemicellulose The speed is faster than that of the fiber, and a certain amount of carbon disulfide is consumed, resulting in a decrease in alkali cellulose esterification and a decrease in the solubility of the sulfonate; d. affecting the filtration of the viscose, the solubility of the sulfonate is lowered, and the potential aldehyde group is oxidized at the end. The metal ions in the carboxyl group and the ash, such as: ferrous ion, manganese ion, calcium ion, magnesium ion, form a highly viscous complex, which leads to difficulty in filtering the viscose and low yield; e. the more hemicellulose, the viscose The poorer the physical and mechanical properties of the fiber. The invention can grind the porridge fed into the press in advance by a grinding machine, and the grinding time is 10-40 s. After the milled porridge is pressed by a press, the mixed lye and alkali cellulose are separated and mixed. The lye contains hemicellulose and other impurities, and is crushed by a pulverizer. The multiple of the pressing is 2.2 to 2.8, and the pulverization degree is 120-180 g/L. By mechanical action, the reaction performance of the porridge is improved to ensure the production of viscose fiber. Smooth progress.

(6) The pulp raw material used in the present invention may be selected from any one or a mixture of two or more of cotton pulp, bamboo pulp, wood pulp and hemp pulp, and may be prepared in any ratio, and the raw material range is applicable widely, and the technical requirements are relatively prepared. Lower, lower raw material costs.

(7) In the step A of the present invention, the lye is a sodium hydroxide solution having a concentration of 110 to 240 g/L, the temperature of the immersion alkali solution is 30 to 60 ° C, and the immersion time is 50 to 90 minutes. Through reasonable parameter setting, the pressing and filtration can be smoothly carried out; if the concentration of lye is too high, the solubility of the obtained cellulose sulfonate will decrease, the filtration of the viscose will be difficult; the concentration of the lye is too low, the pulping degree of the pulp is too high, and the pressing Difficult; the temperature is too high, cellulose depolymerization is fast, accelerate the side reaction, affect the viscose filtration; the temperature is too low, the pulp has a high degree of puffing and the pressing is difficult.

(8) The invention adopts multi-stage purification, such as grinding, pressing and pulverizing, mashing, lye step utilization, for example, adding lye before and after the immersion stage, respectively, not only mentioning the cellulose-bound alkali content, but also increasing the alkali The purpose of the comprehensive utilization of the liquid, at the same time, can also effectively reduce the input cost of the auxiliary lye and reduce the production cost of the viscose fiber.

(9) The invention can obtain alkali cellulose having a fiber content of 29 to 31% and an alkali content of 15 to 17% after grinding and pressing, and the alkali cellulose can be directly fed into the viscose fiber after being subjected to hydrazine oxidation and polycondensation. Production system, viscose fiber production process can be carried out by conventional techniques, such as yellowing to obtain viscose, then filtered, matured, defoamed, and spun to obtain viscose fiber.

(10) In the present invention, the alkali cellulose fiber is treated by a twin-screw equipment to separate the fibers, thereby decomposing the fibers, thereby breaking the cell wall of the cellulose fibers, removing small molecules in the cellulose, thereby increasing the cellulose. The reaction performance improves the cellulose-bound alkali content to 6 to 8% by mass.

(11) The F-step directional depolymerization of the present invention: the alkali cellulose obtained in the step D is mixed with the lye having a concentration of 140-200 g/L to form a porridge having a concentration of 4 to 8%, and the porridge is transported to the directional drop. The polyreactor has a reaction time of 30 to 60 min. After depolymerization, the degree of polymerization of alkali cellulose is reduced from 650 to 1200 to 400 to 600, and the purity of the fiber is 98.0 to 98.5%, which is 2 to 3% higher than the conventional process. The directional depolymerization reduces the loss of the fiber by 3 to 5% compared with the conventional aging, improves the utilization rate of raw materials, saves the production cost, and the molecular degradation is more uniform, sufficient and effective.

(12) The drafting process of the present invention adopts a step-by-step high drafting technique, a drawing ratio of 50 to 100%, a high draft, a high number of filaments, a low draft, and a low strength; and a second draft ratio. 40~60%; three drafting rate is 5~15%, the drafting is too high, the wool is much, the drafting is too low, the strength is decreased, and the brittleness of the fiber is improved and the fiber strength is improved by the reasonable drafting rate control. And reduce the amount of wool, improving the appearance of the product.

(13) The desulfurizing agent composed of sodium sulfide and sodium carbonate in the desulfurization process of the present invention is milder than the sodium hydroxide and sodium sulfite currently used, and can reduce the damage of the strength and elongation of the fiber product, and the sodium carbonate can be neutralized. The tow brought from the acid bath to the sulfuric acid, after the desulfurization process, can be adjusted The pH of the tow is between 8 and 11.

(14) The bleaching agent used in the invention is mild, and the hydrogen peroxide bleaching agent is milder than the bleaching agent such as sodium hypochlorite. The pH of the viscose fiber prepared by the invention should be controlled within the range of 6.5 to 7, and can also be washed with water and palatable acid. The pH is adjusted in the manner of (organic acid), within which the strength of the finished viscose fiber is not affected and the elongation is high.

(15) The invention has reasonable design, comprehensively reduces the production cost of viscose fiber products in the production process of the same viscose fiber product, comprehensively selects the above raw materials, and improves the production cost of the viscose fiber product, and the price thereof is compared with the modal fiber phase. The ratio is 4,000-5,000 yuan/ton, which can greatly reduce the cost of downstream raw materials. It can be used in home textiles, non-woven fabrics, etc., especially underwear, masks, wet wipes, etc., bringing higher profits to downstream enterprises such as spinning and weaving. The added value and broad market prospects significantly enhance the market competitiveness of enterprises.

DRAWINGS

Figure 1 is a cross section of a fiber section of the matte type high strength low stretch viscose fiber of the present invention;

Figure 2 is a cross section of a fiber section of Modal;

Figure 3 is a cross-section of a fiber section of Tencel.

detailed description

The object, technical solution and advantageous effects of the present invention will be further described in detail below.

It is to be understood that the following detailed description is intended to be illustrative of the invention, and the claims of the invention The same meaning of understanding.

Fiber raw materials such as Tencel, Modal, copper ammonia fiber and viscose fiber are bio-based fiber raw materials regenerated from natural cellulose materials. Among them, viscose fiber has the highest market share, but with recent years The scale of viscose fiber of ordinary varieties has expanded rapidly, the supply of raw materials has been tight, and the development of downstream new textiles and industrial upgrading have been gradually restricted. To overcome this phenomenon, a series of differential viscose fibers are exemplified by patent documents CN102296373A, CN1632189 and CN102251301A. It is proposed that the disclosed patented technology can be realized by changing the production process, but for the increasingly fierce market competition, the differentiated viscose fiber is not bigger. The limit meets the development and industrial upgrading of downstream new textiles, especially the development of fiber materials such as Tencel, Modal, and Cuminous fiber, which are also recycled from natural cellulose materials, which makes the market share of viscose fiber decrease. . On the basis of this, the present invention proposes a high-strength low-stretch viscose fiber which has high-strength, low-stretch product characteristics and high absorption characteristics, and the skin-friendly property of the product is far superior to that of modal fiber. Better than cotton fiber.

The high-strength low-stretch viscose fiber of the invention maintains a unique fiber structure during the fiber formation process, and has the characteristics of high strength, and the dry breaking strength and the wet breaking strength are improved by about 25% compared with the ordinary viscose fiber. It is also obviously different from the differentiated viscose fiber. It can be seen from the product index that the product index of high strength and low elongation viscose fiber meets: fineness 0.88~1.67dtex, dry breaking strength≥3.10cN/dtex, wet breaking strength≥1.60 cN/dtex, and the differentiated viscose fiber is exemplified by the patent documents CN102296373A, CN1632189, CN102251301A, and its product specifications are as follows: CN102296373A satisfies the fineness of 0.44~0.78dtex, dry breaking strength≥3.10cN/dtex, wet breaking strength≥2.1cN /dtex;CN1632189 meets the fineness of 0.90~1.40dtex, dry rupture strength ≥2.50cN/dtex, wet rupture strength ≥1.20cN/dtex; CN102251301A meets the fineness of 1.11dtex, strength ≥2.9cN/dtex, as can be seen from the above indicators, this The fiber strength of the high-strength low-stretch viscose fiber involved in the invention is significantly superior to the existing differential viscose fiber.

The high-strength low-stretch viscose fiber according to the present invention is separately compared with the modal fiber and the tencel, and the comparison manner is as follows:

The high-strength low-stretch viscose fiber, the modal fiber, and the tencel were respectively dyed and then subjected to fiber slicing, and the fiber sections were observed under a microscope for 2000 times, as shown in Figs. 1 to 3, and Fig. 1 is a high-strength and low-stretching adhesive of the present invention. The cross-section of the fiber section of the rubber fiber, as shown in Fig. 1, after the dyeing treatment of the high-strength low-stretch viscose fiber of the present invention, the color of the fiber skin layer and the core layer respectively show a difference between shallow and deep, and the difference is large. The cortex is shallow, the core layer is obviously deep, and there is a clear secondary reaction interface, and the proportion is moderate, which ensures that the product has the characteristics of high strength and low elongation, and also has appropriate water absorption, and the fiber skin-friendly property has significant advantages. Among them, the core layer: the "area" ratio of the skin layer is 40 to 70:30 to 60.

Figure 2 is a cross-sectional view of the fiber section of the modal fiber. As shown in Fig. 2, after the dyeing of the modal fiber, the color of the fiber skin layer and the core layer are deep and shallow, and there is no obvious secondary interface. The product features enhance the fiber. Hydrophobic, poor water absorption, which makes it less skin-friendly.

Figure 3 is a cross-sectional view of the fiber section of Tencel. As shown in Figure 3, after the dyeing process, the fiber skin layer and the core layer are dark and light in color, and there is no obvious secondary interface. The product features both common types. The viscose fiber has the advantages of excellent hygroscopicity, smoothness and smoothness, and comfort. It overcomes the defects of ordinary viscose fiber, such as low strength, especially low wet strength. Its strength is almost similar to that of polyester.

It is precisely because of the above characteristics of the product that the matting type high-strength low-stretch viscose fiber according to the present invention satisfies the following indexes:

Dry breaking strength ≥ 3.10cN/dtex, wet breaking strength ≥ 1.60cN/dtex,

The strength required to produce 5% elongation in wet state is ≥0.55 cN/dtex,

The dry elongation at break is 11.0 to 19.0%, and the wet elongation at break is 16.0 to 21.0%.

The matting agent content is 0.8-5%, the whiteness is ≥85%, and the radial water swelling degree is 22-26%.

The linear density deviation rate is ≤±11.0%, and the residual sulfur is ≤12.0mg/100g.

The length deviation rate is ≤±11.0%, and the ultra-long fiber rate is ≤0.5%.

The long fiber ≤ 4.0 mg / 100 g, 疵 point ≤ 4.0 mg / 100g.

The above indicators are applicable to the determination of high strength and low elongation viscose fiber with a linear density ranging from 0.8 dtex to 1.67 dtex. The method for determining the dry rupture strength is GB/T 14337, and the method for determining the wet rupture strength is GB/T 14337. The strength required to produce 5% elongation is achieved by GB/T14337. The method for determining the dry elongation at break is GB/T 14337. The method for determining the wet elongation at break is GB/T 14337. The method for determining the rate is GB/T 14335, the method for determining residual sulfur is FZ/T 50014, the method for measuring the length deviation rate is GB/T 14336, and the method for measuring the ultra-long fiber ratio is GB/T 14336, which is a long fiber. The measurement method is GB/T 14336, the measurement method of the defect is GB/T 14339, the measurement method of whiteness is FZ/T 50013, and the measurement method of radial water swelling degree is GB/T 6503.

The specific embodiments of the present invention are illustrated by the following exemplary embodiments. Of course, the scope of the present invention is not limited to the following embodiments.

Example 1

The high-strength low-stretch viscose fiber according to the embodiment is sequentially impregnated, ground, pressed, pulverized, depolymerized, yellowed, dissolved, filtered, defoamed, matured, spun drawn and post-treated from pulp raw materials. And obtained, determined that the high-strength low-stretch viscose fiber meets:

Dry breaking strength ≥ 3.10cN/dtex;

Wet breaking strength ≥ 1.60cN / dtex;

The strength required to produce 5% elongation in wet state is ≥0.55 cN/dtex,

Dry elongation at break is 11.0 to 19.0%;

Wet elongation at break is 16.0 to 21.0%;

Radial water swelling degree 22 to 26%;

The matting agent content is 0.8 to 5%.

Example 2

The difference between this embodiment and the embodiment 1 is that the high-strength low-stretch viscose fiber according to the embodiment also satisfies:

Whiteness ≥ 85%;

Linear density deviation rate ≤ ± 11.0%;

Residual sulfur ≤ 12.0mg / 100g;

Length deviation rate ≤ ± 11.0%;

Ultra-long fiber rate ≤0.5%;

Double fiber ≤4.0mg/100g;

The defect point is ≤4.0mg/100g.

Example 3

A method for preparing a matting type high-strength low-stretch viscose fiber, the steps are as follows:

A. Put the pulp raw material on the feeding machine first, set the feeding speed to 40kg/min, add the raw material to the dipping bucket, and grind it to make the porridge with the concentration of 3%. The purpose is to open and disperse the fiber by mechanical action, thereby increasing the alkalization speed and alkalization rate of the cellulose;

B. The porridge obtained in step A is sent to a press, and after being pressed, it is sent to a pulverizer for pulverization to obtain alkali cellulose, and the alkali cellulose is sent to a mashing machine to obtain a porridge having a concentration of 30% after the treatment. In this step, the press can remove excess lye, and the excess lye can be recycled. The treatment method is to remove excess hemicellulose from the lye by using a filter with a mesh size of 60 mesh and a vacuum of -0.4 MPa. Alkali cellulose, the use of twin-screw equipment, the fiber can be divided into filaments, deuterated, to break the cell wall of cellulose fibers, remove small molecules in cellulose, thereby improving the cellulose reaction performance, increasing the cellulose-bound alkali content , reaching 6%;

C. The porridge obtained in the step B is mixed with the lye and sent to the reactor, and pure oxygen is added to the reactor, and after depolymerization, alkali cellulose having a degree of polymerization of 400 and a purity of the corn fiber of 98.0% is obtained. In the step, the purpose of adding pure oxygen is oxidative depolymerization.

D. The alkali cellulose obtained in step C is sent to a yellowing machine, carbon disulfide is added to the yellowing machine, and after the yellowing reaction, the cellulose sulfonate obtained by the yellowing reaction is dissolved in a solvent to obtain a concentration of 9.0% cellulose sulfonate solution;

In this embodiment, the pulp raw material is cotton pulp.

Example 4

A: the pulp raw material is immersed in a dipping bucket containing a lye, and ground by a grinder to prepare a porridge having a concentration of 3.5%;

B: The porridge obtained in the step A is sent to a press, and after being pressed, it is sent to a pulverizer for pulverization to obtain alkali cellulose, and the alkali cellulose is sent to a mashing machine to obtain a porridge having a concentration of 32% after the treatment. ;

C: The porridge obtained in the step B is mixed with the lye and sent to the reactor, and pure oxygen is added to the reactor, and after depolymerization, alkali cellulose having a degree of polymerization of 450 and a purity of 98.5% of the methyl fiber is obtained;

D: The alkali cellulose obtained in the step C is sent to a yellowing machine, carbon disulfide is added to the yellowing machine, and after the yellowing reaction, the cellulose sulfonate obtained by the yellow flower reaction is dissolved in a solvent to obtain a concentration of 10.0. % cellulose sulfonate solution;

E: After filtering, defoaming and aging the cellulose sulfonate solution prepared in step D, a matting agent is added to obtain a spinning dope, and the obtained spinning dope is subjected to spinning drafting and post-treatment to obtain a viscose. fiber.

In the above step A, the pulp raw material is a mixture of cotton pulp, bamboo pulp, wood pulp and hemp pulp, the degree of polymerization is 1100, the mixing ratio is 3:2:1:1; the alkali liquid is sodium hydroxide, The concentration was 120 g/L, the immersion temperature was 35 ° C, and the immersion time was 65 min. The grinding machine was placed in a pipe connecting the dip tank and the press. The temperature of the porridge after grinding was 35 ° C, and the grinding time was 35 s.

Example 5

A: the pulp raw material is immersed in a dipping bucket containing a lye, and ground by a grinder to prepare a porridge having a concentration of 4%;

B: The porridge obtained in the step A is sent to a press, and after being pressed, it is sent to a pulverizer for pulverization to obtain alkali cellulose, and the alkali cellulose is sent to a mashing machine to obtain a porridge having a concentration of 35% after the treatment. ;

C: The porridge obtained in the step B is mixed with the lye and sent to the reactor, and pure oxygen is added to the reactor, and after depolymerization, alkali cellulose having a degree of polymerization of 500 and a purity of the fiber of 98.2% is obtained;

D: The alkali cellulose obtained in the step C is sent to a yellowing machine, carbon disulfide is added to the yellowing machine, and after the yellowing reaction, the cellulose sulfonate obtained by the yellow flower reaction is dissolved in a solvent to obtain a concentration of 9.5. % cellulose sulfonate solution;

In the step A of the present embodiment, the pulp raw material is a mixture of wood pulp and hemp pulp, the mixing ratio is 3:1, and the degree of polymerization is 1000.

In the step A of the present embodiment, the alkali solution is sodium hydroxide, the concentration is 110 g/L, the immersion temperature is 30 ° C, and the immersion time is 50 min.

Example 6

B: The porridge obtained in the step A is sent to a press, and after being pressed, it is sent to a pulverizer for pulverization to obtain alkali cellulose, and the alkali cellulose is sent to a mashing machine to obtain a porridge having a concentration of 38% after the treatment. ;

C: the porridge obtained in the step B is mixed with the lye and sent to the reactor, and pure oxygen is added to the reactor, and after depolymerization, alkali cellulose having a degree of polymerization of 550 and a purity of 98.3% of the methyl fiber is obtained;

D: The alkali cellulose obtained in the step C is sent to a yellowing machine, carbon disulfide is added to the yellowing machine, and after the yellowing reaction, the cellulose sulfonate obtained by the yellow flower reaction is dissolved in a solvent to obtain a concentration of 9.6. % cellulose sulfonate solution;

In the above step A, the pulp raw material is a mixture of bamboo pulp, wood pulp and hemp pulp, the degree of polymerization is 900, the mixing ratio is 3:1:1; the alkali liquid is sodium hydroxide, and the concentration thereof is 240 g/L. The immersion temperature is 60 ° C and the immersion time is 90 min; the grinding machine is arranged in a pipe connecting the dip tank and the press, and the temperature of the porridge after grinding is 30 ° C, and the grinding time is 10 s.

Example 7

A method for preparing matt high-strength low-stretch viscose fiber, the steps are as follows

A: the pulp raw material is immersed in a dipping bucket containing a lye, and ground by a grinder to prepare a porridge having a concentration of 6%;

B: The porridge obtained in the step A is sent to a press, and after being pressed, it is sent to a pulverizer for pulverization to obtain alkali cellulose, and the alkali cellulose is sent to a mashing machine to obtain a porridge having a concentration of 40% after the treatment. ;

C: the porridge obtained in the step B is mixed with the lye and sent to the reactor, and pure oxygen is added to the reactor to obtain an alkali cellulose having a degree of polymerization of 600 and a purity of 98.5%.

In this embodiment, the pulp raw material is bamboo pulp, and the degree of polymerization is 800.

In the above step A, the alkali liquid is sodium hydroxide, the concentration is 200 g/L, the immersion temperature is 40 ° C, and the immersion time is 60 min; the grinding machine is arranged in a pipe connecting the dipping bucket and the press, The temperature of the porridge after grinding was 60 ° C, and the grinding time was 40 s.

In the above step B, the pressing temperature of the press was 57 ° C, the pressing ratio was 2.2 times, and the pulverizing degree of the pulverizer was 120 g / L.

Example 8

The difference between this embodiment and the embodiment 4 is that, in the step A, the pulp raw material is a mixture of cotton pulp, bamboo pulp, wood pulp and hemp pulp, the degree of polymerization is 1200, and the mixing ratio is 2:3:1:1; In the step B, the press had a press temperature of 63 ° C and a press multiple of 2.8. Through reasonable adjustment of the pressing ratio and the degree of pulverization, the performance uniformity of the alkali cellulose in the post-processing step can be improved, and the strong extrusion can be prevented from being locally received, thereby hindering the entry of oxygen and reducing the speed of the depolymerization step.

In step C, the lye is a sodium hydroxide solution having a concentration of 140 g/L, and the amount of pure oxygen in the reactor is 2%, and the polymerization reaction time is Controlled at 30min.

Example 9

A method for preparing a matt high-strength low-stretch viscose fiber, comprising the following steps:

C: the porridge obtained in the step B is mixed with the lye and sent to the reactor, and pure oxygen is added to the reactor, and after depolymerization, alkali cellulose having a degree of polymerization of 600 and a purity of the corn fiber of 98.0% is obtained;

In the above step A, the pulp raw material is a mixture of cotton pulp, bamboo pulp, wood pulp and hemp pulp, the degree of polymerization is 1100, the mixing ratio is 3:2:1:1; the alkali liquid is sodium hydroxide, The concentration is 180g / L, the immersion temperature is 50 ° C, the immersion time is 55min; the grinding machine is arranged in the pipe connecting the dipping bucket and the press, the temperature of the porridge after grinding is 45 ° C, the grinding time is 20 s; In the step B, the pressing temperature of the press is 60 ° C, the pressing multiple is 2.6 times, the pulverization degree of the pulverizer is 160 g / L; in the step C, the alkali liquid is sodium hydroxide having a concentration of 200 g / L The solution, the pure oxygen in the reactor was added in an amount of 10%, and the depolymerization reaction time was controlled at 60 min.

In the step D of the present embodiment, the amount of carbon disulfide added is 25% of the content of the methyl fiber in the alkali cellulose obtained in the step B; the yellowing reaction time is controlled at 45 minutes, and the yellowing reaction temperature is 20 ° C. The dissolution is carried out by mixing, stirring and grinding the cellulose sulfonate with a solvent comprising a sodium sulfite solution having a concentration of 25 g/L sodium hydroxide solution and a concentration of 5 g/L, and the dissolution temperature is 10 ° C. The dissolution time is 30 min.

Example 10

The difference between this embodiment and the embodiment 9 is that in the step C, the lye is a sodium hydroxide solution having a concentration of 140 g/L, the amount of pure oxygen in the reactor is 5%, and the depolymerization reaction time is controlled at 45 min. .

In the step D of the present embodiment, the amount of carbon disulfide added is 37% of the content of the methyl fiber in the alkali cellulose obtained in the step B; the yellowing reaction time is controlled at 50 min, and the yellowing reaction temperature is 30 ° C. The solution is to mix, stir and grind the cellulose sulfonate with a solvent comprising a sodium sulfite solution having a concentration of 45 g/L sodium hydroxide solution and a concentration of 10 g/L, and the dissolution temperature is 20 ° C. The dissolution time is 50 min.

Example 11

The difference between this embodiment and the embodiment 8 is that in the step C, the alkali liquid is a sodium hydroxide solution having a concentration of 160 g/L; in the step D, the carbon disulfide is added in the amount of the alkali cellulose obtained in the step B. 30% of the fiber content; the yellowing reaction time is controlled at 48 minutes, and the yellowing reaction temperature is 26 ° C. The dissolution is mixing, stirring and grinding the cellulose sulfonate with a solvent, and the solvent includes The concentration was 30 g/L sodium hydroxide solution and a sodium sulfite aqueous solution having a concentration of 8 g/L. The dissolution temperature was 15 ° C and the dissolution time was 44 min.

In this embodiment, titanium dioxide is used as a matting agent.

Example 12

The difference between this embodiment and the embodiment 9 is that in the step A, the pulp raw material is a mixture of cotton pulp, bamboo pulp, wood pulp and hemp pulp, the degree of polymerization is 1000, and the mixing ratio is 4:2:1:1.

In step E, the specific steps of the spinning draft are as follows:

F: the cellulose sulfonate solution is filtered, defoamed, and matured, and then sent to a spinning machine, which is extruded from a nozzle of a spinning machine and passed through a bath to form a tow, and the one bath is solidified. The bath comprises 90 g/L of sulfuric acid, 220 g/L of sodium sulfate and 8 g/L of zinc sulfate;

G: the tow after one bath is fed into the two bath by a drafting machine, the coagulation bath used in the two baths comprises 18 g/L of sulfuric acid, and the drafting ratio of the one drafting machine is 50%;

H: The tow after the two baths is fed into the three baths by a two-way drafting machine, the coagulation bath used in the three baths includes sulfuric acid having a pH of 1, and the drafting ratio of the two drafting machines is 40%. ;

I: The tow after three baths was sent to the after-treatment portion by a three-way drafting machine, and the draft ratio of the three-way drafting machine was 5%.

Example 13

The difference between this embodiment and the embodiment 9 is that in the step C, the alkali solution is a sodium hydroxide solution having a concentration of 190 g/L, the amount of pure oxygen in the reactor is 3%, and the depolymerization reaction time is controlled at 50 min. .

In step E, the specific steps of the spinning draft are as follows:

F: the cellulose sulfonate solution is filtered, defoamed, and matured, and then sent to a spinning machine, which is extruded from a nozzle of a spinning machine and passed through a bath to form a tow, and the one bath is solidified. The bath comprises 120 g/L of sulfuric acid, 280 g/L of sodium sulfate and 15 g/L of zinc sulfate;

G: the tow after one bath is fed into the two bath by a drafting machine, the coagulation bath used in the two baths comprises 18-22 g/L of sulfuric acid, and the drafting ratio of the one drafting machine is 60%;

H: The tow after the two baths is sent to the three baths by a two-way drafting machine, and the coagulation bath used in the three baths includes sulfuric acid having a pH of 3, and the drafting ratio of the two drafting machines is 45%. ;

I: The tow after three baths was sent to the after-treatment portion by a three-way drafting machine, and the draft ratio of the three-way drafting machine was 8%.

In this embodiment, the one bath temperature is 40 ° C, the two bath temperature is 80 ° C, and the three bath temperature is 80 ° C.

Example 14

The difference between this embodiment and the embodiment 13 is that in the step E, the post-process includes desulfurization, bleaching and oiling, and the desulfurizing agent used in the desulfurization has a concentration of 4 g/L of sodium sulfide and a concentration of 4 g/L. The sodium carbonate composition is used; the bleaching agent used for the bleaching is hydrogen peroxide at a concentration of 0.3 g/L; the oil used for the oiling is added in an amount of 7 g/L, and the pH of the tow after oiling is 6.5.

The spinning drafting steps are as follows:

F: the cellulose sulfonate solution is filtered, defoamed, and matured, and then sent to a spinning machine, which is extruded from a nozzle of a spinning machine and passed through a bath to form a tow, and the one bath is solidified. The bath comprises 100 g/L of sulfuric acid, 250 g/L of sodium sulfate and 10 g/L of zinc sulfate;

G: the tow after one bath is fed into the two bath by a drafting machine, the coagulation bath used in the two baths comprises 20 g/L of sulfuric acid, and the drafting ratio of the one drafting machine is 80%;

H: The tow after the two baths is fed into the three baths by a two-way drafting machine, the coagulation bath used in the three baths includes sulfuric acid having a pH of 2, and the drafting ratio of the two drafting machines is 50%. ;

I: The tow after three baths was sent to the after-treatment portion by a three-way drafting machine, and the draft ratio of the three-way drafting machine was 10%.

The one bath temperature was 50 ° C, the two bath temperature was 85 ° C, and the three bath temperature was 80 ° C.

Example 15

The difference between this embodiment and the embodiment 12 is that in the spinning drafting step, the bath temperature is 44 ° C, the two bath temperature is 90 ° C, and the three bath temperature is 90 ° C; the desulfurization is used. The desulfurizing agent is composed of sodium sulfide having a concentration of 8 g/L and sodium carbonate having a concentration of 1 g/L; the bleaching agent used for the bleaching is hydrogen peroxide at a concentration of 0.6 g/L; and the amount of the oil used for the oiling is 9 g. /L, the pH of the tow after oiling is 7; the desulfurization temperature is 50 ° C, the desulfurization time is 3 min; the bleaching temperature is 50 ° C, the bleaching time is 2 min; the temperature of the oil agent is 50 °C.

Example 16

A: The pulp raw material is immersed in a dipping bucket containing a lye, the pulp raw material is a mixture of cotton pulp, bamboo pulp, wood pulp and hemp pulp, the degree of polymerization is 1100, and the mixing ratio is 3:2: 1:1; the concentration of the lye is 180g / L, the temperature is 50 ° C, the immersion time is 55min; after immersion, grinding by a grinder, the grinding time is 20s, after grinding, the slurry is prepared at a concentration of 4% and a temperature of 45 ° C Porridge

B: The porridge obtained in the step A is sent to a press, the pressing temperature is 60 ° C, the pressing multiple is 2.6 times, and after being pressed, it is sent to a pulverizer for pulverization, and the pulverization degree is 120 g/L to obtain alkali cellulose. The alkali cellulose is sent to a crucible, and after treatment, a porridge having a concentration of 35% is obtained;

C: The porridge obtained in the step B is mixed with the lye having a concentration of 190 g/L and sent to the reactor, and 2% pure oxygen is added to the reactor, and the degree of polymerization is 450, and the purity of the fiber is obtained after 50 minutes of depolymerization. 98.1% alkali cellulose;

D: The alkali cellulose obtained in the step C is sent to a yellowing machine, and 35% of carbon disulfide in the alkali cellulose obtained in the step B is added to the yellowing machine, and after being yellowed at 20 ° C for 45 minutes, The cellulose sulfonate obtained by the yellowing reaction is dissolved in a solvent, wherein the solvent is sodium hydroxide having a concentration of 25 g/L and an aqueous solution of sodium sulfite having a concentration of 5 g/L, the dissolution temperature is 10 ° C, and the dissolution time is 30 min. , obtaining a cellulose sulfonate solution having a concentration of 9.5%;

E: after the cellulose sulfonate solution prepared in the step D is filtered, defoamed, and matured, a certain amount of matting agent is added, and the matting agent of the present embodiment is selected from titanium dioxide, and the spinning dope is obtained after being uniformly stirred;

F: the cellulose sulfonate solution is filtered, defoamed, and matured, and then sent to a spinning machine, which is extruded from a nozzle of a spinning machine through a bath to form a tow, and the temperature of the one bath is At 42 ° C, the coagulation bath used comprises 120 g / L of sulfuric acid, 280 g / L of sodium sulfate and 15 g / L of zinc sulfate;

G: The tow after one bath is fed into a two bath by a drafting machine, the temperature of the two baths is 80 ° C, the coagulation bath used includes 20 g / L of sulfuric acid, and the drafting ratio of the one drafting machine 60%;

H: The tow after the two baths is fed into the three baths by a two-way drafting machine, the temperature of the three baths is 80 ° C, and the coagulation bath used includes sulfuric acid having a pH of 2, the two-way drafting machine The drafting rate is 45%;

The post treatment of this example includes desulfurization, bleaching, and oiling and drying. The desulfurizing agent used for the desulfurization is composed of sodium sulfide having a concentration of 5 g/L and sodium carbonate having a concentration of 2 g/L, the desulfurization temperature is 55 ° C, the desulfurization time is 3 min; and the bleaching agent used for the bleaching is a concentration of 0.5 g. / L of hydrogen peroxide, bleaching temperature of 55 ° C, bleaching time of 1 min; the oil used to add oil is 8g / L, the pH of the tow after oiling is 7, the temperature of the oil is 55 ° C; The post-treatment drying is to perform desulfurization, bleaching and tow obtained after spinning the tow, and the tow obtained by the oiling is dried by a dryer, the drying temperature is 115 ° C, and after drying, the extinction is obtained. High-strength low-stretch viscose fiber products.

Example 17

A: The pulp raw material is immersed in an immersion tank containing an alkali solution, the concentration of the alkali liquid is 120 g/L, the temperature is 40 ° C, and the immersion time is 60 min; after immersion, it is ground by a grinder, and the grinding time is 15 s, after grinding Preparing a porridge having a concentration of 4% and a temperature of 45 ° C;

B: The porridge obtained in the step A is sent to a press, the pressing temperature is 60 ° C, the pressing multiple is 2.6 times, and after being pressed, it is sent to a pulverizer for pulverization, and the pulverization degree is 180 g/L to obtain alkali cellulose. The alkali cellulose is sent to a crucible, and after treatment, a porridge having a concentration of 32% is obtained;

C: The porridge obtained in the step B is mixed with the lye having a concentration of 150 g/L, and then sent to the reactor, 10% pure oxygen is added to the reactor, and the degree of polymerization is 600, and the purity of the fiber is obtained after 40 minutes of depolymerization. 98% alkali cellulose;

D: The alkali cellulose obtained in the step C is sent to a yellowing machine, and 32% of the carbon fiber content of the alkali fiber in the alkali cellulose obtained in the step B is added to the yellowing machine, and after 48 minutes of yellowing at 26 ° C, The cellulose sulfonate obtained by the yellowing reaction is dissolved in a solvent, wherein the solvent is sodium hydroxide having a concentration of 35 g/L and an aqueous solution of sodium sulfite having a concentration of 8 g/L, the dissolution temperature is 15 ° C, and the dissolution time is 40 min. , obtaining a cellulose sulfonate solution having a concentration of 9.6%;

F: the cellulose sulfonate solution is filtered, defoamed, and matured, and then sent to a spinning machine, which is extruded from a nozzle of a spinning machine through a bath to form a tow, and the temperature of the one bath is At 40 ° C, the coagulation bath used comprises 120 g / L of sulfuric acid, 280 g / L of sodium sulfate and 15 g / L of zinc sulfate;

G: The tow after one bath is fed into a two bath by a drafting machine, the temperature of the two bath is 80 ° C, the coagulation bath used includes 19 g / L of sulfuric acid, and the drafting ratio of the one drafting machine 60%;

The post treatment of this example includes desulfurization, bleaching, and oiling and drying. The desulfurizing agent used for the desulfurization is composed of sodium sulfide having a concentration of 6 g/L and sodium carbonate having a concentration of 3 g/L, the desulfurization temperature is 52 ° C, the desulfurization time is 2.5 min; and the bleaching agent used for the bleaching is a concentration of 0.5. g/L of hydrogen peroxide, bleaching temperature is 50 ° C, bleaching time is 2 min; the oil used in the oiling is 9 g / L, the pH of the tow after oiling is 7, the temperature of the oil is 53 ° C The post-treatment drying is to perform desulfurization, bleaching and tow obtained after spinning the tow, and the tow obtained after oiling is dried by a dryer, the drying temperature is 75 ° C, and after drying, Matte type high strength low stretch viscose fiber products.

In the step A, the pulp raw material is a mixture of cotton pulp, bamboo pulp, wood pulp and hemp pulp, the degree of polymerization is 1200, and the mixing ratio is 1:2:4:1.

Example 18

B: The porridge obtained in the step A is sent to a press, the pressing temperature is 60 ° C, the pressing multiple is 2.6 times, and after being pressed, it is sent to a pulverizer for pulverization, the pulverization degree is 130 g/L, and alkali cellulose is obtained. The alkali cellulose is sent to a crucible, and after treatment, a porridge having a concentration of 35% is obtained;

C: The porridge obtained in the step B is mixed with the lye having a concentration of 150 g/L and sent to the reactor, and 5% pure oxygen is added to the reactor, and the degree of polymerization is 450, and the purity of the fiber is obtained after 40 minutes of depolymerization. 98.1% alkali cellulose;

D: The alkali cellulose obtained in the step C is sent to a yellowing machine, and 35% of carbon disulfide in the alkali cellulose obtained in the step B is added to the yellowing machine, and after being yellowed at 26 ° C for 48 minutes, The cellulose sulfonate obtained by the yellowing reaction is dissolved in a solvent, wherein the solvent is sodium hydroxide having a concentration of 35 g/L and an aqueous solution of sodium sulfite having a concentration of 8 g/L, the dissolution temperature is 15 ° C, and the dissolution time is 40 min. , obtaining a cellulose sulfonate solution having a concentration of 9.5%;

F: the cellulose sulfonate solution is filtered, defoamed, and matured, and then sent to a spinning machine, which is extruded from a nozzle of a spinning machine through a bath to form a tow, and the temperature of the one bath is At 42 ° C, the coagulation bath used comprises 100 g / L of sulfuric acid, 230 g / L of sodium sulfate and 10 g / L of zinc sulfate;

G: The tow after one bath is fed into a two bath by a drafting machine, the temperature of the two bath is 85 ° C, the coagulation bath used includes 20 g / L of sulfuric acid, and the drafting ratio of the one drafting machine 100%;

H: The tow after the two baths is fed into the three baths by a two-way drafting machine, the temperature of the three baths is 87 ° C, and the coagulation bath used includes sulfuric acid having a pH of 2, the two drafting machines The draw ratio is 60%;

I: The tow after three baths was sent to the after-treatment portion by a three-way drafting machine, and the draft ratio of the three-way drafting machine was 15%.

The post treatment of this example includes desulfurization, bleaching, and oiling and drying. The desulfurizing agent used for the desulfurization is composed of sodium sulfide having a concentration of 5 g/L and sodium carbonate having a concentration of 2 g/L, the desulfurization temperature is 55 ° C, the desulfurization time is 2 min; and the bleaching agent used for the bleaching is a concentration of 0.5 g. / L of hydrogen peroxide, bleaching temperature of 52 ° C, bleaching time of 1 min; the oil used to add oil is 8g / L, the pH of the tow after oiling is 7, the temperature of the oil is 53 ° C; The post-treatment drying is obtained after desulfurization, bleaching and oiling of the tow formed by the spinning drafting. The tow is dried by a dryer, and the drying temperature is 95 ° C. After drying, a matt high-strength low-stretch viscose fiber product is obtained.

In the step A, the pulp raw material is a mixture of cotton pulp, bamboo pulp, wood pulp and hemp pulp, the degree of polymerization is 650, and the mixing ratio is 1:1:2:1.

The viscose fibers obtained in Examples 3 to 18 were tested, and the index statistics were as follows, wherein Examples 3 to 10 are shown in Table 1, Examples 11 to 18 are shown in Table 2, and the index values of the viscose fibers of Examples 3 to 18 were taken. The average value and the average value are compared with the test indexes of the modal fiber, the differentiated viscose fiber (CN102296373A comparison document 1, CN1632189 comparison document 2, CN102251301A comparison document 3) and ordinary viscose fiber, respectively, as shown in Table 3.

Table 1

Table 2

table 3

It can be seen from Tables 1 and 2 that the viscose fiber products prepared in Examples 4, 5 and 6 are mainly used in the field of compact siro spinning, producing sorghum and high count yarn products, and are suitable for sorghum, etc. with high product strength. The field demand is characterized; the viscose fiber products obtained by the preparation of the examples 10, 11, 12, 13, 14, 15, 16, 17, 18 are mainly used in the production of underwear and high-grade woven fabrics, and the products are silky and soft to the touch. The comfort and skin-friendly, as well as the dimensional stability of the finished fabric are good; the viscose fiber products prepared in Examples 8, 9, and 10 are mainly used in the field of denim fabric, and are characterized by being bright, soft, and characterized by a small variation of the finished fabric. .

The matte type high-strength low-stretch viscose fiber product prepared in Examples 3 to 18 was arbitrarily selected, and as shown in Example 16, the fiber section was subjected to microscopic screenshots, and it was found that the cross section retained clear reaction traces and the fiber cortex The color of the core layer shows a shallow and deep difference, the skin layer is obviously shallow, and the core layer is deep. (Inner layer + middle layer): The ratio of the "area" of the outer layer is 60:37, belonging to the core layer: cortex = (40 to 70): Within the range of (30 to 60).

According to the data analysis of Table 3, the high-strength low-stretch viscose fiber of the present invention has an index system different from ordinary viscose fiber, differentiated viscose fiber and modal fiber, and the dry breaking strength and wet breaking strength of the viscose fiber of the present invention. It is obviously higher than ordinary viscose fiber, and the elongation is obviously lower than that of ordinary viscose fiber. Through the setting of process parameters, the viscose fiber of the invention has obvious secondary reaction interface, thereby ensuring high strength and low elongation equivalent to modal. The characteristic is that the radial water swelling degree is higher than that of the modal fiber, and has higher hygroscopicity than the modal, so the skin-friendly property is better than the modal fiber; the viscose fiber of the invention is a novel viscose fiber capable of It effectively replaces existing modal fibers and ordinary viscose fibers, and has lower production cost and good economic and social benefits.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modifications and equivalent changes to the above embodiments in accordance with the technical spirit of the present invention fall within the scope of the present invention. Within the scope of protection.

Claims

The matting type high-strength low-stretch viscose fiber is characterized in that the pulp raw material is sequentially impregnated, ground, pressed, crushed, smashed, depolymerized, yellowed, dissolved, filtered, defoamed, matured, spun drawn and post-treated. After obtaining a high-strength low-stretch viscose fiber, the high-strength low-stretch viscose fiber satisfies:

Dry breaking strength ≥ 3.10cN/dtex;

Wet breaking strength ≥ 1.60cN / dtex;

The strength required to produce 5% elongation in wet state is ≥0.55 cN/dtex,

Dry elongation at break is 11.0 to 19.0%;

Wet elongation at break is 16.0 to 21.0%;

Crystallinity 40.0 to 45.0%;

Radial water swelling degree 22 to 26%;

The matting agent content is 0.8 to 5%.
The matt high-strength low-extension viscose fiber according to claim 1, wherein the pulp raw material comprises one or a combination of two or more of cotton pulp, bamboo pulp, wood pulp, and hemp pulp.
The matt high-strength low-extension viscose fiber according to claim 1, wherein the pulp raw material has a degree of polymerization of from 650 to 1200.
The method for preparing a matting type high-strength low-stretch viscose fiber according to any one of claims 1 to 3, wherein the preparation method comprises immersing the pulp raw material in an alkali solution, grinding, crushing, smashing, smashing After depolymerization, alkali cellulose is obtained after removing the alkali solution, and the alkali cellulose is yellowed and dissolved to obtain a cellulose sulfonate solution, and the cellulose sulfonate solution is filtered, defoamed, matured, and spun. After stretching and post-treatment, high-strength low-stretch viscose fibers are obtained.
The method for preparing a matting type high-strength low-stretch viscose fiber according to claim 4, wherein the steps of the preparation method are as follows:

A: immersing the pulp raw material in a dipping bucket containing an alkali solution, and grinding it by a grinder to prepare a porridge having a concentration of 3 to 6%;

B: The porridge obtained in the step A is sent to a press, and after being pressed, it is sent to a pulverizer for pulverization to obtain alkali cellulose, and the alkali cellulose is sent to a crucible, and the concentration is 30-40% after the treatment. Pulp porridge

C: The porridge obtained in the step B is mixed with the lye and sent to the reactor, and pure oxygen is added to the reactor to obtain an alkali fiber having a polymerization degree of 400 to 600 and a purity of the fiber of 98.0 to 98.5% after depolymerization. Prime

D: The alkali cellulose obtained in the step C is sent to a yellowing machine, carbon disulfide is added to the yellowing machine, and after the yellowing reaction, the cellulose sulfonate obtained by the yellowing reaction is dissolved in a solvent to obtain a concentration of 9.0 to 10.0% cellulose sulfonate solution;

E: After filtering, defoaming, and aging the cellulose sulfonate solution prepared in the step D, the spinning dope is added to obtain a spinning dope, and the obtained spinning dope is subjected to spinning drafting and post-treatment to obtain a viscosity. Glue fiber.
The method for preparing a matting type high-strength low-extension viscose fiber according to claim 5, wherein in the step A, the alkali liquid is a sodium hydroxide solution having a concentration of 110 to 240 g/L, and the alkali is impregnated. The temperature of the liquid is 30 to 60 ° C, and the immersion time is 50 to 90 minutes.
The method for preparing a matt high-strength low-extension viscose fiber according to claim 5, wherein in the step A, the grinder is disposed in a pipe connecting the dipping bucket and the press.
The method for preparing a matting type high-strength low-extension viscose fiber according to claim 5, wherein in the step A, the temperature of the porridge is 30 to 60 ° C, and the grinding time of the grinder It is 10 to 40 s.
The method for preparing a matting type high-strength low-extension viscose fiber according to claim 5, wherein in the step B, the pressing temperature of the press is 57 to 63 ° C, and the pressing multiple is 2.2 to 2.8. .
The method for producing a matt high-strength low-extension viscose fiber according to claim 5, wherein in the step B, the pulverizer has a pulverization degree of 120 to 180 g/L.
The method for preparing a matting type high-strength low-extension viscose fiber according to claim 5, wherein in the step C, the alkali solution is a sodium hydroxide solution having a concentration of 140 to 200 g/L, and the reaction The amount of pure oxygen added in the device is 2-10%, and the depolymerization reaction time is controlled at 30-60 min.
The method for preparing a matting type high-strength low-extension viscose fiber according to claim 5, wherein in the step D, the amount of carbon disulfide added is 25 in the amount of the methyl cellulose in the alkali cellulose obtained in the step B. ~37%.
The method for preparing a matting type high-strength low-extension viscose fiber according to claim 5, wherein in the step D, the yellowing reaction time is controlled at 45 to 50 minutes, and the yellowing reaction temperature is 20 ~30 ° C.
The method for preparing a matt high-strength low-extension viscose fiber according to claim 5, wherein in the step D, the dissolving is mixing, stirring and grinding the cellulose sulfonate with a solvent. The solvent includes a sodium hydroxide solution having a concentration of 25 to 45 g/L and an aqueous sodium sulfite solution having a concentration of 5 to 10 g/L.
The method for preparing a matt high-strength low-extension viscose fiber according to claim 5, wherein in the step D, the dissolution temperature is 10 to 20 ° C, and the dissolution time is 30 to 50 min.
The method for preparing a matt high-strength low-extension viscose fiber according to claim 5, wherein in the step E, the matting agent is titanium dioxide.
The method for preparing a matt high-strength low-extension viscose fiber according to claim 5, wherein the spinning drafting step as follows:

F: the cellulose sulfonate solution is filtered, defoamed, and matured, and then sent to a spinning machine, which is extruded from a nozzle of a spinning machine and passed through a bath to form a tow, and the one bath is solidified. The bath comprises 90-120 g/L of sulfuric acid, 220-280 g/L of sodium sulfate and 8-15 g/L of zinc sulfate;

G: The tow after one bath is fed into the two bath by a drafting machine, the coagulation bath used in the two baths comprises 18-22 g/L of sulfuric acid, and the drafting ratio of the one drafting machine is 50-100. %;

H: The tow after the two baths is fed into the three baths by a two-way drafting machine, and the coagulation bath used in the three baths includes sulfuric acid having a pH of 1 to 3, and the draft ratio of the two drafting machines is 40 to 60%;

I: The tow after three baths was sent to the after-treatment portion by a three-way drafting machine, and the draft ratio of the three-way drafting machine was 5 to 15%.
The method for preparing a matting type high-strength low-extension viscose fiber according to claim 17, wherein in the spinning drawing step, the temperature of the one bath is 40 to 50 ° C, and the temperature of the two baths is 80 to 90 ° C, three bath temperature of 80 to 90 ° C.
The method for preparing a matt high-strength low-extension viscose fiber according to claim 5, wherein the post-treatment comprises desulfurization, bleaching and oiling the tow formed by the spinning draft, the desulfurization The desulfurizing agent used is composed of sodium sulfide having a concentration of 4 to 8 g/L and sodium carbonate having a concentration of 1 to 4 g/L; the bleaching agent used for the bleaching is hydrogen peroxide having a concentration of 0.3 to 0.6 g/L; The amount of the oil to be used is 7 to 9 g/L, and the pH of the tow after oiling is 6.5 to 7.
The method for preparing a matt high-strength low-extension viscose fiber according to claim 19, wherein the desulfurization temperature is 50 to 55 ° C, the desulfurization time is 2 to 3 min, and the bleaching temperature is 50 to 55. °C, bleaching time is 1-2 minutes; the temperature of the oil agent is 50-55 °C.
The method for preparing a matting type high-strength low-extension viscose fiber according to claim 19, wherein the post-treatment further comprises drying, the drying temperature is 75 to 115 ° C, and after drying, the obtained Matte type high strength low stretch viscose fiber products.