阅读说明：本技术 一种耐水洗阻燃粘胶面料 (Washable flame-retardant viscose fabric ) 是由 张天俊 于 2021-09-08 设计创作，主要内容包括：本发明公开了一种耐水洗阻燃粘胶面料,粘胶面料中包括阻燃粘胶纤维；粘胶纤维的制备方法包括如下步骤：浸渍、压榨、老成、黄化、纺前注入、纺丝、集束、牵伸、切断、水洗一、脱硫、水洗二、酸洗：水洗三、上油浴、烘干、打包。在纺丝前将阻燃剂水分散液、超支化纳米纤维素水分散液和分散剂,采用纺前注射系统均匀加入纺丝胶中。所使用的阻燃粘胶在生产中,采用纺丝前将阻燃剂水分散液、超支化纳米纤维素水分散液和分散剂,采用纺前注射系统均匀加入纺丝胶中,使得阻燃剂在后续凝固浴中阻燃剂的残留率高,并且提高了阻燃剂和纳米纤维素的分散性能,使得阻燃剂的分散更均匀。阻燃剂的残留率超过了95％,限氧指数超过了33％。(The invention discloses a washable flame-retardant viscose fabric, which comprises flame-retardant viscose fibers; the preparation method of the viscose fiber comprises the following steps: dipping, squeezing, ageing, yellowing, injecting before spinning, bundling, drafting, cutting, washing with water I, desulfurizing, washing with water II and pickling: and (4) washing with water, performing oil bath, drying and packaging. And before spinning, uniformly adding the flame retardant aqueous dispersion, the hyperbranched nano-cellulose aqueous dispersion and the dispersing agent into the spinning glue by adopting a pre-spinning injection system. In the production of the flame-retardant viscose, the flame retardant water dispersion, the hyperbranched nano-cellulose water dispersion and the dispersing agent are uniformly added into the spinning viscose by a pre-spinning injection system, so that the residual rate of the flame retardant in a subsequent coagulation bath is high, the dispersing performance of the flame retardant and the nano-cellulose is improved, and the dispersion of the flame retardant is more uniform. The residual rate of the flame retardant exceeds 95 percent, and the limited oxygen index exceeds 33 percent.)

1. The washable flame-retardant viscose fabric is characterized in that the viscose fabric comprises flame-retardant viscose fibers; the preparation method of the viscose fiber comprises the following steps:

(1) dipping: putting cellulose pulp into an impregnation barrel, wherein the temperature of the impregnation barrel is 56-58 ℃, the time is 30-35min, the concentration is 220-;

(2) squeezing: pressing and crushing the raw materials by a presser, wherein the fixed volume weight is 130-140 g/L;

(3) aging: aging the crushed raw materials at 52-55 deg.C with outlet copper viscosity of 50-52 mp;

(4) yellowing: 32-34% of carbon disulfide to the first fiber, 25-35 minutes of yellowing time and 25-30 ℃;

(5) injecting before spinning: uniformly adding the flame retardant water dispersion, the hyperbranched nano-cellulose water dispersion and the dispersing agent into spinning glue by adopting a pre-spinning injection system before spinning;

the flame retardant aqueous dispersion contains 180-200g/L sodium metasilicate; the hyperbranched nano-cellulose aqueous dispersion contains 50-100g/L of hyperbranched polyamide functionalized nano-cellulose and ethylenediamine modified nano-cellulose; the sodium metasilicate accounts for 44 to 46 percent of the addition amount of the alpha fibers in terms of silicon dioxide;

(6) and spinning: the temperature of the coagulation bath is 45-55 ℃, the concentration of sulfuric acid is 110-135g/L, the concentration of zinc sulfate is 25-35g/L, the concentration of aluminum sulfate is 10-15g/L, the concentration of sodium sulfate is 270-300g/L, the concentration of orthosilicic acid is 10-15g/L, and the fall of the acid bath is 6-12 g/L;

(7) bundling: the front and rear steam pressures are respectively 0.25MPa and 0.15MPa, the water replenishing temperature of the plasticizing tank is more than or equal to 80 ℃, the acid content of the plasticizing tank is 20-35g/L, the temperature of a main condensation gap bridge is less than or equal to 50 ℃, and the final condensation temperature is less than or equal to 25 ℃;

(8) drafting: the drawing rate from a spinning head to a godet is 30-60%, the drawing rate from the godet to a first set is 20-40%, the drawing rate from the first set to a second set is 7-12%, and the total drawing rate is 80-150%;

(9) cutting off;

(10) washing with water: the water temperature is normal temperature;

(11) and (3) desulfurization: desulfurizing by using a sodium sulfite solution, wherein the concentration of the sodium sulfite solution is 4-8g/L, and the temperature of the sodium sulfite solution is 75-80 ℃;

(12) and (2) washing with water: the water temperature is normal temperature;

(13) acid washing: pickling with hydrochloric acid with pH of 4-6 at normal temperature;

(14) and (3) washing with water: washing with water at 45-55 deg.C;

(15) and (3) oil bath: the concentration of the used oil agent is 3-6g/L, the temperature is 45-55 ℃, and the pH value is 7-8.5;

(16) and (5) drying and packaging.

2. The washable flame-retardant viscose fabric as recited in claim 1, wherein said viscose fabric is a knitted fabric woven from flame-retardant viscose yarns, said flame-retardant viscose yarns being prepared from flame-retardant viscose fibers by ring spinning.

3. The washable flame-retardant viscose fabric according to claim 2, wherein the preparation method of the flame-retardant viscose yarn comprises the following steps:

(a) a blowing procedure: placing the flame-retardant viscose on a blowing circular table, and waiting to be grabbed, wherein the descending speed of a beater of a plucker is 2mm each time, the rotating speed is 960r/min, the speed of a rotary trolley is 2.8r/min, the blade extends out of a rib for 2mm, the beater speed is 800r/min, the fan speed is 950r/min, the space between the beater and a balance roller is 12mm, the speed of a lap roller is 12r/min, the dry weight ration of a lap is 350g/m, and the length of the lap is 30.9 m;

(b) cotton carding process: the speed of a cylinder is 280r/min, the speed of a licker-in is 590r/min, the speed of a doffer is 15.8r/min, the speed of a cover plate is 89mm/min, the distance between the cylinder and the licker-in is 7-inch, the distance between a cotton feeding plate and the licker-in is 20-inch, the distance between the cylinder and the doffer is 4-inch, the distance between 5 points of the cylinder and the cover plate is 10-inch multiplied by 9-inch multiplied by 8-inch multiplied by 9-inch, the height of a dust removing knife is flat with a machine frame, and an included angle between the knife back and the horizontal plane of the machine frame is 90 degrees;

(c) drawing: after three times of mixing, 7 pieces of the raw materials are mixed and combined, the bell mouth is 3mm, the dry weight ration of the mixture is 17.5g/5 m, the roller gauge is 12mm multiplied by 20mm, the mechanical drafting is 6.3 times, and the back zone drafting is 1.6 times; secondly, the dry weight ration is 17.5g/5 m, the roller gauge is 12mm multiplied by 20mm, the mechanical drafting is 6.86 times, and the back zone drafting is 1.4 times; third, the dry weight ration is 17.5g/5 m, the roller gauge is 18mm multiplied by 25mm, the mechanical drafting is 6.86 times, the back zone drafting is 1.3 times, and the final combined Uster evenness is within 4.5 percent;

(d) roving: the twist of the roving is 3.2 twists/10 cm, the roller gauge is 28mm multiplied by 38mm, the back zone drafting is 1.17 times, the jaw gauge is 9mm, the dry weight ration of the roving is 5.26g/10 m, the mechanical drafting is 6.8 times, the rotating speed of the front roller is 200r/min, the wet weight is 5.63g/10m, the special number 563tex, the twist coefficient is 76, the diameter of the front roller is 28mm, and the palm pressing winding number is 2 circles;

(e) spinning: the mechanical draft multiple is 31.92 times, the roller gauge is 22mm multiplied by 41mm, the draft multiple of the rear zone is 1.18 times, the jaw gauge is 3.5mm, the diameter of the front roller is 27mm, and the rotating speed of the front roller is 158 r/min; 10-20 counts of the prepared flame-retardant viscose yarn, the twist number is 480-710T/m, and the twist direction is S.

4. The washable flame-retardant viscose fabric according to claim 2, wherein said viscose fabric is a rib fabric or a single-side knitted fabric woven by flame-retardant viscose yarns.

5. The washable flame-retardant viscose fabric according to claim 1, wherein the hyperbranched polyamide functionalized nanocellulose and the ethylenediamine modified nanocellulose are in a ratio of 1-2: 1, mixing; the dispersing agent is polyvinyl alcohol.

Technical Field

The invention relates to the technical field of flame-retardant viscose fabrics, in particular to a washable flame-retardant viscose fabric.

Background

The main flame-retardant fabrics at present comprise: post-finishing flame-retardant fabrics such as pure cotton, polyester cotton and the like; and the intrinsic flame-retardant fabric is aramid fiber, nitrile cotton, Kevlar Dupont, Nomex, Australian PR97 and the like. According to market conditions analysis, the North American, Medium American and European Flame Retardant (FR) technologies are particularly well developed. The situation indicates that the market will continue to develop and need innovation, as taught by John philier, the technical market manager (formerly Apex chemical production, inc.) of Spartanburg, south carolina, usa; in particular, there is a greater interest in technology that can pass the state of california/Consumer Product Safety Commission (CPSC) bedding standards and non-halogen flame retardant treatments.

The development of common viscose staple fibers has been 100 years old so far, the quality index requirements and the detection method of the common viscose staple fibers are in the GB/T14463-2008 standard, the common viscose staple fibers have no flame retardance and can only be used in the traditional common weaving industry. Flame-retardant fibers are generally used in the field of special working environments and household articles, as clothing, decorations, industrial fabrics and the like. The flame-retardant fiber mainly comprises two types, one type is a permanent flame-retardant fiber, and at present, the permanent flame-retardant fiber is mainly permanent flame-retardant polyester or aramid fiber, nitrile cotton, Dupont Kevlar, Nomex and the like. At present, more permanent flame-retardant fibers have better flame-retardant property, but the larger thermal shrinkage of the permanent flame-retardant fibers can cause secondary damage when being used as a special protective fabric, and the wearability of moisture absorption, air permeability and the like is poorer. The other is that the fiber or fabric with the surface attached with the flame retardant is not resistant to washing and sunshine, and after long-term use, the surface flame retardant component falls off and loses effectiveness, and the flame retardant property can not meet the design requirement. In the chinese patent application with publication number CN1904156A, a flame retardant viscose staple fiber and its production process are disclosed, which is characterized by adding flame retardant in the viscose fiber production process to make the viscose fiber have permanent flame retardant effect. But the added flame retardant has poor dispersion condition and low residual rate of the flame retardant, which causes poor flame retardant effect of the flame retardant adhesive. The existing viscose staple fibers can not play a good flame-retardant role when being applied to textile production, particularly flame-retardant textile products, and the flame-retardant effect is unsatisfactory. Accordingly, it is desirable to have a viscose staple fiber yarn with good flame retardancy that simultaneously meets the federal standard 16CFR1633 and british BS5852 fire protection standard requirements.

Disclosure of Invention

The invention aims to provide a washable flame-retardant viscose fabric, which is characterized in that flame retardant aqueous dispersion, hyperbranched nano-cellulose aqueous dispersion and a dispersing agent are injected before spinning, so that the residual rate of a flame retardant in a subsequent coagulation bath is high, the utilization rate of the flame retardant is improved, the dispersing performance of the flame retardant and nano-cellulose is improved, and the dispersion of the flame retardant is more uniform.

In order to solve the technical problem, the invention aims to realize that:

the invention relates to a washable flame-retardant viscose fabric, which comprises flame-retardant viscose fibers; the preparation method of the viscose fiber comprises the following steps:

(1) dipping: putting cellulose pulp into an impregnation barrel, wherein the temperature of the impregnation barrel is 56-58 ℃, the time is 30-35min, the concentration is 220-;

(2) squeezing: pressing and crushing the raw materials by a presser, wherein the fixed volume weight is 130-140 g/L;

(3) aging: aging the crushed raw materials at 52-55 deg.C with outlet copper viscosity of 50-52 mp;

(4) yellowing: 32-34% of carbon disulfide to the first fiber, 25-35 minutes of yellowing time and 25-30 ℃;

(5) injecting before spinning: uniformly adding the flame retardant water dispersion, the hyperbranched nano-cellulose water dispersion and the dispersing agent into spinning glue by adopting a pre-spinning injection system before spinning;

the flame retardant aqueous dispersion contains 180-200g/L sodium metasilicate; the hyperbranched nano-cellulose aqueous dispersion contains 50-100g/L of hyperbranched polyamide functionalized nano-cellulose and ethylenediamine modified nano-cellulose; the sodium metasilicate accounts for 44 to 46 percent of the addition amount of the alpha fibers in terms of silicon dioxide;

(6) and spinning: the temperature of the coagulation bath is 45-55 ℃, the concentration of sulfuric acid is 110-135g/L, the concentration of zinc sulfate is 25-35g/L, the concentration of aluminum sulfate is 10-15g/L, the concentration of sodium sulfate is 270-300g/L, the concentration of orthosilicic acid is 10-15g/L, and the fall of the acid bath is 6-12 g/L;

(7) bundling: the front and rear steam pressures are respectively 0.25MPa and 0.15MPa, the water replenishing temperature of the plasticizing tank is more than or equal to 80 ℃, the acid content of the plasticizing tank is 20-35g/L, the temperature of a main condensation gap bridge is less than or equal to 50 ℃, and the final condensation temperature is less than or equal to 25 ℃;

(8) drafting: the drawing rate from a spinning head to a godet is 30-60%, the drawing rate from the godet to a first set is 20-40%, the drawing rate from the first set to a second set is 7-12%, and the total drawing rate is 80-150%;

(9) cutting off;

(10) washing with water: the water temperature is normal temperature;

(11) and (3) desulfurization: desulfurizing by using a sodium sulfite solution, wherein the concentration of the sodium sulfite solution is 4-8g/L, and the temperature of the sodium sulfite solution is 75-80 ℃;

(12) and (2) washing with water: the water temperature is normal temperature;

(13) acid washing: pickling with hydrochloric acid with pH of 4-6 at normal temperature;

(14) and (3) washing with water: washing with water at 45-55 deg.C;

(15) and (3) oil bath: the concentration of the used oil agent is 3-6g/L, the temperature is 45-55 ℃, and the pH value is 7-8.5;

(16) and (5) drying and packaging.

On the basis of the above scheme and as a preferable scheme of the scheme: the viscose fabric is a knitted fabric woven by flame-retardant viscose yarns, and the flame-retardant viscose yarns are prepared by ring spinning flame-retardant viscose fibers.

On the basis of the above scheme and as a preferable scheme of the scheme: the preparation method of the flame-retardant viscose yarn comprises the following steps:

(a) a blowing procedure: placing the flame-retardant viscose on a blowing circular table, and waiting to be grabbed, wherein the descending speed of a beater of a plucker is 2mm each time, the rotating speed is 960r/min, the speed of a rotary trolley is 2.8r/min, the blade extends out of a rib for 2mm, the beater speed is 800r/min, the fan speed is 950r/min, the space between the beater and a balance roller is 12mm, the speed of a lap roller is 12r/min, the dry weight ration of a lap is 350g/m, and the length of the lap is 30.9 m;

(b) cotton carding process: the speed of a cylinder is 280r/min, the speed of a licker-in is 590r/min, the speed of a doffer is 15.8r/min, the speed of a cover plate is 89mm/min, the distance between the cylinder and the licker-in is 7-inch, the distance between a cotton feeding plate and the licker-in is 20-inch, the distance between the cylinder and the doffer is 4-inch, the distance between 5 points of the cylinder and the cover plate is 10-inch multiplied by 9-inch multiplied by 8-inch multiplied by 9-inch, the height of a dust removing knife is flat with a machine frame, and an included angle between the knife back and the horizontal plane of the machine frame is 90 degrees;

(c) drawing: after three times of mixing, 7 pieces of the raw materials are mixed and combined, the bell mouth is 3mm, the dry weight ration of the mixture is 17.5g/5 m, the roller gauge is 12mm multiplied by 20mm, the mechanical drafting is 6.3 times, and the back zone drafting is 1.6 times; secondly, the dry weight ration is 17.5g/5 m, the roller gauge is 12mm multiplied by 20mm, the mechanical drafting is 6.86 times, and the back zone drafting is 1.4 times; third, the dry weight ration is 17.5g/5 m, the roller gauge is 18mm multiplied by 25mm, the mechanical drafting is 6.86 times, the back zone drafting is 1.3 times, and the final combined Uster evenness is within 4.5 percent;

(d) roving: the twist of the roving is 3.2 twists/10 cm, the roller gauge is 28mm multiplied by 38mm, the back zone drafting is 1.17 times, the jaw gauge is 9mm, the dry weight ration of the roving is 5.26g/10 m, the mechanical drafting is 6.8 times, the rotating speed of the front roller is 200r/min, the wet weight is 5.63g/10m, the special number 563tex, the twist coefficient is 76, the diameter of the front roller is 28mm, and the palm pressing winding number is 2 circles;

(e) spinning: the mechanical draft multiple is 31.92 times, the roller gauge is 22mm multiplied by 41mm, the draft multiple of the rear zone is 1.18 times, the jaw gauge is 3.5mm, the diameter of the front roller is 27mm, and the rotating speed of the front roller is 158 r/min; 10-20 counts of the prepared flame-retardant viscose yarn, the twist number is 480-710T/m, and the twist direction is S.

On the basis of the above scheme and as a preferable scheme of the scheme: the viscose fabric is rib fabric or single-sided knitted fabric woven by flame-retardant viscose yarns.

On the basis of the above scheme and as a preferable scheme of the scheme: the hyperbranched polyamide functionalized nano-cellulose and the ethylenediamine modified nano-cellulose are prepared from the following raw materials in a proportion of 1-2: 1, mixing; the dispersing agent is polyvinyl alcohol.

The invention has the beneficial effects that: according to the washable flame-retardant viscose fabric, the flame-retardant viscose is produced by uniformly adding the flame retardant water dispersion, the hyperbranched nano-cellulose water dispersion and the dispersing agent into the spinning glue by using a pre-spinning injection system before spinning, so that the residual rate of the flame retardant in a subsequent coagulation bath is high, the utilization rate of the flame retardant is improved, the dispersing performance of the flame retardant and the nano-cellulose is improved, and the dispersion of the flame retardant is more uniform. The residual rate of the flame retardant exceeds 95 percent, and the limited oxygen index exceeds 33 percent.

Detailed Description

The present invention is further illustrated by the following specific examples.

Example one

According to the washable flame-retardant viscose fabric, the viscose fabric comprises flame-retardant viscose fibers; the viscose fabric is a knitted fabric woven by flame-retardant viscose yarns, and the flame-retardant viscose yarns are prepared by ring spinning flame-retardant viscose fibers. The viscose fabric is rib fabric or single-sided knitted fabric woven by flame-retardant viscose yarns. The preparation method of the viscose fiber comprises the following steps:

(1) dipping: the cellulose pulp is put into an impregnation barrel, the temperature of the impregnation barrel is 56 ℃, the time is 30min, the concentration is 220g/L, and the dosage of V-388 accounts for 0.08 percent of the content of the methyl cellulose.

(2) Squeezing: the raw materials are pressed and crushed by a presser, and the basis weight is 130 g/L.

(3) Aging: aging the crushed raw materials at 52 ℃ until the outlet copper viscosity is 50 mp.

(4) Yellowing: the addition of carbon disulfide to the methyl fiber is 32 percent, the yellowing time is 25 minutes, and the temperature is 25 ℃.

(5) Injecting before spinning: and before spinning, uniformly adding the flame retardant aqueous dispersion, the hyperbranched nano-cellulose aqueous dispersion and the dispersing agent into the spinning glue by adopting a pre-spinning injection system.

The flame retardant water dispersion liquid contains 180g/L sodium metasilicate; the hyperbranched nano-cellulose aqueous dispersion contains 50g/L of hyperbranched polyamide functionalized nano-cellulose and ethylenediamine modified nano-cellulose. The sodium metasilicate accounts for 44 percent of the addition amount of the alpha fibers calculated by silicon dioxide.

Further, the hyperbranched polyamide functionalized nanocellulose and the ethylenediamine modified nanocellulose are prepared according to the weight ratio of 1-2: 1, mixing; the dispersing agent is polyvinyl alcohol.

Adding the dissolved sodium metasilicate into the spinning glue as a dissolving solution, in order to ensure that the flame retardant is dispersed in the flame-retardant viscose in a nano-scale manner by using metasilicic acid, and the sodium metasilicate solution is added in a large amount, so that the composition of the viscose is greatly changed, although the alkali content in the viscose is greatly improved, the melting and curing stability of the flame-retardant viscose are facilitated, the diffusion speed and the permeability of the flame-retardant viscose are reduced, the dissolution of the fiber xanthate is not facilitated, the number and the diameter of gel particles in the flame-retardant viscose are greatly improved, the sodium metasilicate is permeated into an external solution in the subsequent solidification and water washing processes, and the residual rate of the flame retardant sodium metasilicate is greatly reduced. In order to improve the binding capacity of sodium metasilicate with cellulose in the flame-retardant viscose glue, hyperbranched polyamide functionalized nanocellulose and ethylenediamine modified nanocellulose are added, the hyperbranched polyamide functionalized nanocellulose and the ethylenediamine modified nanocellulose can have good binding capacity with the cellulose, and a cavity can be formed between each branched chain of hyperbranched polymer for the sodium metasilicate, so that the sodium metasilicate can not permeate into external solution in the subsequent treatment process and can be retained in the flame-retardant viscose glue. Due to the fact that the hyperbranched polyamide functionalized nano-cellulose and the ethylenediamine modified nano-cellulose are added, the viscosity of the spinning glue can be improved, and therefore the flame retardant is not easy to be fully and uniformly mixed with the spinning glue, polyvinyl alcohol is added as a dispersing agent, the dispersing performance of sodium metasilicate, the hyperbranched polyamide functionalized nano-cellulose and the ethylenediamine modified nano-cellulose is improved, and the flame retardant performance of the prepared flame retardant viscose fiber is more uniform.

(6) And spinning: the temperature of the coagulation bath is 45 ℃, the concentration of sulfuric acid is 110g/L, the concentration of zinc sulfate is 25g/L, the concentration of aluminum sulfate is 10g/L, the concentration of sodium sulfate is 270g/L, the concentration of orthosilicic acid is 10g/L, and the fall of the acid bath is 6 g/L.

The main function of zinc sulphate and aluminium sulphate is to solidify the viscose flow and to counteract the dissociation of sulphuric acid, so that the regeneration rate of cellulose xanthate is retarded. There are three additional special functions: firstly, the cellulose xanthate can react with the sodium cellulose xanthate to generate the zinc cellulose xanthate and the aluminum cellulose xanthate, the decomposition speed of the zinc cellulose xanthate and the aluminum cellulose xanthate in a coagulating bath is much slower than that of the sodium cellulose xanthate, so that the coagulation regeneration of viscose trickle is mild, and the viscose trickle is completely decomposed after strong stretching, thereby reducing the breakage of the fiber, improving the spinnability of the fiber, and enabling the fiber to obtain higher strength and elongation indexes. Secondly, the zinc cellulose xanthate and the aluminum cellulose xanthate are crystal centers, and a large amount of zinc cellulose xanthate, aluminum cellulose xanthate and hyperbranched nanocellulose exist, so that a large amount of uniform small crystal blocks can be generated by taking the zinc cellulose xanthate and the aluminum cellulose xanthate as the centers, the fibers are made into uniform microcrystalline structures, the strength of the fibers is improved, the fiber is not easy to break in the forming process, and the spinnability of the fibers is improved. And thirdly, the addition of the aluminum sulfate effectively inhibits the overflow loss of aluminum ions in the flame-retardant viscose glue, and improves the ash content of the fiber and the high-temperature resistance of the flame retardant. Therefore, in the process of forming the flame-retardant viscose by the spinning coagulating bath, the improvement of the content of zinc sulfate and aluminum sulfate not only can effectively improve the spinnability of the viscose, but also can improve the strength index, the flame retardance and the high temperature resistance index of the fiber. Too high zinc sulfate and aluminum sulfate content not only affects economic indexes and brings difficulty to environmental treatment, but also affects fiber forming speed. Production practice proves that due to the addition of the hyperbranched polyamide functionalized nanocellulose and the ethylenediamine modified nanocellulose, the concentrations of zinc sulfate and aluminum sulfate are optimally controlled to be 25g/L and 15g/L respectively.

(7) Bundling: the front and back steam pressures are respectively 0.25MPa and 0.15MPa, the water temperature of the plasticizing tank is more than or equal to 80 ℃, and the temperature is controlled at 98 ℃. The content of sulfuric acid in the plasticizing tank is 20g/L, the main condensation gap bridge temperature is less than or equal to 50 ℃, and the final condensation temperature is less than or equal to 25 ℃.

(8) Drafting: the draw ratio from the spinneret to the godet was 30%, the draw ratio from the godet to the integrated one was 20%, the draw ratio from the integrated one to the integrated two was 7%, and the total draw ratio was 80%.

(9) And (6) cutting off. The drawn viscose filaments were cut to the desired length, 38 mm.

(10) Washing with water: the water temperature is normal temperature.

(11) And (3) desulfurization: and desulfurizing by using a sodium sulfite solution, wherein the concentration of the sodium sulfite solution is 4g/L, and the temperature of the sodium sulfite solution is 75 ℃.

(12) And (2) washing with water: the water temperature is normal temperature.

(13) Acid washing: hydrochloric acid with pH value of 4 and normal temperature is adopted for acid cleaning.

(14) And (3) washing with water: the washing with water was carried out at 45 ℃.

(15) And (3) oil bath: the concentration of the used oil agent is 3g/L, the temperature is 45 ℃, and the pH value is 7;

sulfuric acid and sulfate brought by the fiber from a coagulating bath are removed through water washing, water-soluble impurities such as sulfur and the like attached to the surface of the strand silk are removed, sulfur and carbon disulfide in the fiber are removed through sodium sulfite desulfurization, alkali mixed in the fiber post-treatment process is removed through weak acid washing, and the looseness and hand feeling of the fiber are improved through oiling. Sodium sulfite is used for desulfurization because the desulfurization of sodium sulfite is the most moderate among three substances of caustic soda, sodium sulfide and sodium sulfite, and the damage to the strength of fibers is the least.

The flame-retardant viscose fiber prepared in this example was subjected to ash content measurement, flame retardant residue rate measurement, oxygen limiting index measurement, breaking strength and elongation at break measurement.

Test for analysis of moisture:

the instrument equipment comprises a constant-temperature air-blast oven with a temperature regulator, a dryer, a flat weighing bottle and an electronic balance with the sensing quantity of 0.1 mg.

Secondly, accurately weighing the humidity-adjusted sample 29 to about (accurately weighing to 0.00019), putting the sample into a flat weighing bottle with known weight, opening the bottle cap, putting the bottle cap and the bottle cap into a constant-temperature blast oven, heating to 105 ℃ and 2 ℃, drying for 2.5 hours to constant weight, capping the weighing bottle, and transferring the bottle into a dryer for cooling and weighing.

Calculating:

in the formula: g-sample weight before baking, G; g1-weight of sample and bottle before baking, G; g2-weight of sample and bottle after baking, G.

And (3) determining the ash content:

instrument equipment: a high temperature furnace with a temperature regulator, a 30ml porcelain crucible, a dryer, a crucible tongs, and an electronic balance with a sensing quantity of 0.1 mg.

The measuring method comprises the following steps: accurately weighing about 49 (accurately weighing to 0.00019) of a humidity-adjusted sample, putting the sample into a fired ceramic crucible with constant weight, carbonizing the sample for about 15min in a high-temperature electric furnace at 320 to 350 ℃ (below the ignition point) until no smoke exists, then heating the sample to 750.780 ℃, firing the sample for about 2.5 hours until no black carbon exists and the constant weight is reached, taking the sample out, precooling the sample in air for 7min, and then placing the sample in a dryer for cooling and weighing.

Calculating:

wherein G1 is ash and crucible weight, G; g2-empty crucible weight, G; g-the conditioned sample weight, G; w-water content W%.

The test was performed 5 times, and the test results were 31.2%, 31.4%, 31.8%, 32.3%, and 31.5%, respectively, with an average value of 31.6%.

And (3) determination of the residual quantity of the flame retardant: the content of the flame retardant in the inorganic flame-retardant cellulose fiber is rapidly determined by adopting a low-field pulse nuclear magnetic resonance method, and is compared with the proportion of the added flame retardant in the alpha cellulose. Tests show that the residual quantity of the fire retardant sodium metasilicate reaches 96.2 percent.

Determination of oxygen limiting index: five tests were performed, and the test results were as follows: 32.4%, 33.7%, 34.1%, 35.3%, 32.5%, the average result was 33.6%.

Therefore, the prepared flame-retardant viscose has good flame retardant residual rate and oxygen limiting index and good flame-retardant effect.

The flame-retardant viscose fiber prepared in this example was tested for dry breaking strength and dry elongation at break, and the test results were as follows:

number of tests	1	2	3	4	5	Mean value of
							Fiber dry strength/cN/dtex	1.38	1.26	1.36	1.28	1.32	1.32
Dry elongation/percent of fiber	31.5	30.8	29.7	30.5	29.4	30.4

The ring spinning preparation method of the flame-retardant viscose yarn comprises the following steps:

(a) a blowing procedure: placing the flame-retardant viscose on a blowing circular table, and waiting to be grabbed, wherein the descending speed of a beater of a plucker is 2mm each time, the rotating speed is 960r/min, the speed of a rotary trolley is 2.8r/min, the blade extends out of a rib for 2mm, the beater speed is 800r/min, the fan speed is 950r/min, the space between the beater and a balance roller is 12mm, the speed of a lap roller is 12r/min, the dry weight ration of a lap is 350g/m, and the length of the lap is 30.9 m;

(b) cotton carding process: the speed of a cylinder is 280r/min, the speed of a licker-in is 590r/min, the speed of a doffer is 15.8r/min, the speed of a cover plate is 89mm/min, the distance between the cylinder and the licker-in is 7-inch, the distance between a cotton feeding plate and the licker-in is 20-inch, the distance between the cylinder and the doffer is 4-inch, the distance between 5 points of the cylinder and the cover plate is 10-inch multiplied by 9-inch multiplied by 8-inch multiplied by 9-inch, the height of a dust removing knife is flat with a machine frame, and an included angle between the knife back and the horizontal plane of the machine frame is 90 degrees;

(c) drawing: after three times of mixing, 7 pieces of the raw materials are mixed and combined, the bell mouth is 3mm, the dry weight ration of the mixture is 17.5g/5 m, the roller gauge is 12mm multiplied by 20mm, the mechanical drafting is 6.3 times, and the back zone drafting is 1.6 times; secondly, the dry weight ration is 17.5g/5 m, the roller gauge is 12mm multiplied by 20mm, the mechanical drafting is 6.86 times, and the back zone drafting is 1.4 times; third, the dry weight ration is 17.5g/5 m, the roller gauge is 18mm multiplied by 25mm, the mechanical drafting is 6.86 times, the back zone drafting is 1.3 times, and the final combined Uster evenness is within 4.5 percent;

(d) roving: the twist of the roving is 3.2 twists/10 cm, the roller gauge is 28mm multiplied by 38mm, the back zone drafting is 1.17 times, the jaw gauge is 9mm, the dry weight ration of the roving is 5.26g/10 m, the mechanical drafting is 6.8 times, the rotating speed of the front roller is 200r/min, the wet weight is 5.63g/10m, the special number 563tex, the twist coefficient is 76, the diameter of the front roller is 28mm, and the palm pressing winding number is 2 circles;

(e) spinning: the mechanical draft multiple is 31.92 times, the roller gauge is 22mm multiplied by 41mm, the draft multiple of the rear zone is 1.18 times, the jaw gauge is 3.5mm, the diameter of the front roller is 27mm, and the rotating speed of the front roller is 158 r/min; 10-20 counts of the prepared flame-retardant viscose yarn, the twist number is 480-710T/m, and the twist direction is S.

The twist and strength test results of the prepared ring spun flame-retardant viscose yarn are as follows:

number of branches/number of branches	twist/T/m	Strength/cN
			10	580s	440
12	600s	440
			14	620s	400
16	660s	350
			18	700s	300
20	730s	280

The prepared flame-retardant viscose yarn is subjected to a flame-retardant performance test, and meets the requirements of the fire-retardant standard of 16CFR1633 and BS5852 in the UK.

The rib knitted fabric and the single-sided knitted fabric prepared from the ring spun flame-retardant viscose yarn have the following parameters:

the process data of the thread cloth are as follows: breadth: 70cm × 2-150cm × 2; gram weight: 170gsm to 380 gsm.

Single-side cloth process data: breadth: 180cm-240 cm; gram weight: 150gsm to 340 gsm.

The prepared threaded cloth and single-sided cloth are not melted, have no molten drops, have no smoke generation, have the continuous combustion time of 0s and the smoldering time of 0s, are permanently flame-retardant, and have comfortable wear and soft hand feeling. The same flame retardant effect as before washing was still obtained after 5, 10 and 15 washes.

The viscose flame-retardant yarn fabric product is not used for other flame-retardant knitted fabrics, and due to the special post finishing and the special flame retardant adding process method, the viscose flame-retardant yarn fabric product is environment-friendly and green (pollution-free in the production process), enables the product cloth to have the permanent flame-retardant characteristic, and simultaneously meets the fire-retardant standards of the Federal Standard 16CFR1633 and the British BS 5852.

Moisture absorption: has good hygroscopicity, and can absorb water into ambient atmosphere under normal conditions, and has water content of 8-10%, so that it can contact human skin to make human feel soft and not rigid. If the humidity of the cloth is increased and the ambient temperature is higher, the moisture content in the fiber can be completely evaporated and dispersed, so that the fabric keeps a water balance state and people feel comfortable.

Moisture retention: because the flame-retardant viscose staple fiber is a poor conductor of heat and electricity, the heat conduction coefficient is extremely low, and because the viscose staple fiber has the advantages of porosity and high elasticity, a large amount of air can be accumulated between the fibers, and the air is a poor conductor of heat and electricity, the flame-retardant viscose segment fiber textile has good moisture retention.

Heat resistance: the full-viscose short-fiber fabric has good heat resistance.

Alkali resistance: the resistance to alkali is high, the fiber is not damaged in the alkali solution, and the performance is favorable for washing pollution after being taken, disinfecting and removing impurities.

Sanitation: the fiber is natural fiber, and the main component of the fiber is resin viscose cellulose.

Flame retardancy: has permanent flame retardant property.

Example two

According to the washable flame-retardant viscose fabric, the viscose fabric comprises flame-retardant viscose fibers; the viscose fabric is a knitted fabric woven by flame-retardant viscose yarns, and the flame-retardant viscose yarns are prepared by ring spinning flame-retardant viscose fibers. The viscose fabric is rib fabric or single-sided knitted fabric woven by flame-retardant viscose yarns. The preparation method of the viscose fiber comprises the following steps:

(1) dipping: the cellulose pulp is put into an impregnation barrel, the temperature of the impregnation barrel is 58 ℃, the time is 35min, the concentration is 235g/L, and the dosage of V-388 accounts for 0.10 percent of the content of the methyl cellulose.

(2) Squeezing: the raw materials are pressed and crushed by a presser, and the basis weight is 140 g/L.

(3) Aging: aging the crushed raw materials at 55 ℃ until the copper viscosity at the outlet is 52 mp.

(4) Yellowing: the addition of carbon disulfide to the methyl fiber is 34 percent, the yellowing time is 35 minutes, and the temperature is 30 ℃.

(5) Injecting before spinning: and before spinning, uniformly adding the flame retardant aqueous dispersion, the hyperbranched nano-cellulose aqueous dispersion and the dispersing agent into the spinning glue by adopting a pre-spinning injection system.

The flame retardant water dispersion liquid contains 200g/L sodium metasilicate; the hyperbranched nano-cellulose aqueous dispersion contains 100g/L of hyperbranched polyamide functionalized nano-cellulose and ethylenediamine modified nano-cellulose. The sodium metasilicate accounts for 46 percent of the addition amount of the alpha fibers calculated by silicon dioxide.

Further, the hyperbranched polyamide functionalized nanocellulose and the ethylenediamine modified nanocellulose are prepared according to the weight ratio of 1-2: 1, mixing; the dispersing agent is polyvinyl alcohol.

(6) And spinning: the temperature of the coagulation bath is 55 ℃, the concentration of sulfuric acid is 135g/L, the concentration of zinc sulfate is 35g/L, the concentration of aluminum sulfate is 15g/L, the concentration of sodium sulfate is 300g/L, the concentration of orthosilicic acid is 15g/L, and the fall of the acid bath is 12 g/L.

(7) Bundling: the front and back steam pressures are respectively 0.25MPa and 0.15MPa, the water temperature of the plasticizing tank is more than or equal to 80 ℃, and the temperature is controlled at 98 ℃. The content of sulfuric acid in the plasticizing tank is 35g/L, the main condensation gap bridge temperature is less than or equal to 50 ℃, and the final condensation temperature is less than or equal to 25 ℃.

(8) Drafting: the draw ratio from the spinneret to the godet was 60%, the draw ratio from the godet to the integrated one was 40%, the draw ratio from the integrated one to the integrated two was 12%, and the total draw ratio was 150%.

(9) And (6) cutting off. The drawn viscose filaments were cut to the desired length, 51 mm.

(10) Washing with water: the water temperature is normal temperature.

(11) And (3) desulfurization: and desulfurizing by using a sodium sulfite solution, wherein the concentration of the sodium sulfite solution is 8g/L, and the temperature of the sodium sulfite solution is 80 ℃.

(12) And (2) washing with water: the water temperature is normal temperature.

(13) Acid washing: hydrochloric acid with pH value of 6 and normal temperature is adopted for acid cleaning.

(14) And (3) washing with water: the washing was carried out at 55 ℃.

(15) And (3) oil bath: the concentration of the used oil agent is 6g/L, the temperature is 55 ℃, and the pH value is 8.5;

the flame-retardant viscose fiber prepared in this example was subjected to ash content measurement, flame retardant residue rate measurement, oxygen limiting index measurement, breaking strength and elongation at break measurement.

The test was performed 5 times, and the test results were 31.5%, 31.1%, 31.9%, 31.7%, and 30.8%, respectively, with an average value of 31.4%.

And (3) determination of the residual quantity of the flame retardant: the content of the flame retardant in the inorganic flame-retardant cellulose fiber is rapidly determined by adopting a low-field pulse nuclear magnetic resonance method, and is compared with the proportion of the added flame retardant in the alpha cellulose. Tests show that the residual quantity of the fire retardant sodium metasilicate reaches 95.9 percent.

Determination of oxygen limiting index: five tests were performed, and the test results were as follows: 32.7%, 33.5%, 34.6%, 35.5%, 32.2%, the average result was 33.7%.

Therefore, the prepared flame-retardant viscose has good flame retardant residual rate and oxygen limiting index and good flame-retardant effect.

The flame-retardant viscose fiber prepared in this example was tested for dry breaking strength and dry elongation at break, and the test results were as follows:

the twist and strength test results of the yarn prepared from the flame-retardant viscose yarn are as follows:

number of branches/number of branches	twist/T/m	Strength/cN
			10	480s	204
12	530s	213
			14	580s	229
16	630s	252
			18	670s	265
20	710s	283

The prepared threaded cloth and single-sided cloth are not melted, have no molten drops, have no smoke generation, have the continuous combustion time of 0s and the smoldering time of 0s, are permanently flame-retardant, and have comfortable wear and soft hand feeling. The same flame retardant effect as before washing was still obtained after 5, 10 and 15 washes.

Comparative example

The comparative example differs from example one in that:

injecting before spinning in the step (5): before spinning, only the flame retardant water dispersion is uniformly added into the spinning glue by adopting a pre-spinning injection system. And hyperbranched nano-cellulose water dispersion and a dispersing agent are not added.

And (3) determining the residual quantity of the flame retardant: the content of the flame retardant in the inorganic flame-retardant cellulose fiber is rapidly determined by adopting a low-field pulse nuclear magnetic resonance method, and is compared with the proportion of the added flame retardant in the alpha cellulose. The test shows that the residual quantity of the fire retardant sodium metasilicate reaches 87.6 percent.

And measuring the oxygen limiting index: five tests were performed, and the test results were as follows: 29.4%, 30.3%, 29.5%, 31.6%, 30.5%, with an average result of 30.26%.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.