CN115772811B - Cold pad-batch dyeing process capable of preventing fibrillation of lyocell woven fabric - Google Patents

Abstract

The invention belongs to the technical field of textile production and processing, and particularly relates to a cold pad-batch dyeing process capable of preventing fibrillation of a lyocell woven fabric. The method comprises the following steps: preparing a treatment solution of amylase and a penetrating agent, regulating the pH value of the treatment solution to be 4-6, padding and desizing working solution of the greige cloth of the lyocell woven fabric, rolling and stacking, washing with hot water, washing with water at normal temperature, and drying; padding the fabric with a solution containing a fibrillation-preventing treating agent, drying, baking, washing with water and drying; preparing reactive dye liquor and color fixing liquor, mixing the prepared dye liquor and color fixing liquor to prepare dyeing working liquor, padding the fabric with the dyeing working liquor, rolling and piling, washing with hot water, soaping, washing with cold water, and drying. The invention saves refining bleaching process, uses anti-fibrillation treatment agent to perform anti-fibrillation treatment before dyeing, improves the anti-fibrillation capability of the lyocell fabric, adopts cold pad-batch dyeing process to dye the lyocell woven fabric, reduces the friction between the fabric and equipment, and reduces the fibrillation tendency.

Description

Cold pad-batch dyeing process to prevent fibrillation of lyocell woven fabrics

Technical Field

The invention belongs to the field of textile production technology and processing, and in particular relates to a cold pad-batch dyeing process capable of preventing lyocell woven fabric from fibrillation.

Background technique

Lyocell fiber is a regenerated cellulose fiber made from wood pulp and N-methylmorpholine-N-oxide (NMMO) as solvent through a dry-jet wet spinning process. During its production process, the solvent recovery rate is more than 99.7%, and the waste is biodegradable, so it is a recognized green fiber. Lyocell fiber fabrics have the same "comfort" as cotton, close to the "strength" of polyester, as well as the "beauty" of wool and the "touch" and "soft drape" effect of silk, and are widely used in the production of high-end textile fabrics. However, Lyocell fiber has a unique fibrillation characteristic. After friction in a wet state, it will split into fibrils with a diameter of less than 1 micron in the axial direction of the fiber, causing the fabric to have light color or "frost" or white lines or scratches and other printing and dyeing defects. Lyocell woven fabrics are usually dyed using an open-width continuous processing technology. Under the conditions of wet heat, alkalinity and mechanical friction, the lateral swelling of the fiber makes the stiff fabric more easily fibrillated, resulting in serious fabric quality problems.

At present, the main methods to solve the fibrillation problem of Lyocell woven fabrics include fiber cross-linking treatment, resin finishing and cellulase depilation. For example, "Research Progress on Anti-Fibrillation of Lyocell Fibers" introduces that Lenzing Company used dichlorotriazine cross-linking agents to cross-link cellulose. Compared with the original Lyocell fibers, the cross-linked fibers have significantly improved anti-fibrillation performance. CN201911296394.9 introduces a method for preparing non-fibrillated Lyocell fibers. Lyocell fibers are treated with 1,3,5-triacryloylhexahydro-1,3,5-triazine (TAHT) anti-fibrillation aid to produce a Lyocell fiber with a relatively low fibrillation tendency. "The Effect of Cross-linking Treatment on the Fibrillation Properties of Lyocell Fibers" uses 1,2,3,4-butanetetracarboxylic acid (BTCA) to treat Lyocell fibers, which can also enhance the interaction between fiber macromolecular chains and reduce fibrillation to a certain extent. "The Effect of Oligomeric Maleic Acid-Citric Acid Crosslinking Treatment on the Anti-fibrillation Performance of Lyocell Fibers" mixed the polycarboxylic acid citric acid (CA) with oligomeric maleic acid and then crosslinked with Lyocell fibers. "Fibrillation Control Methods and Evaluation Criteria for Lyocell Fiber Home Textile Fabrics" introduced the research on the fibrillation of Lyocell fabrics after dyeing resin finishing. The study showed that the anti-pilling grade can be improved after selecting the right resin to finish Lyocell fibers. "Study on the Fibrillation and Anti-fibrillation of Lyocell Fibers" introduced the research on cellulase in the prevention and control of fibrillation of Lyocell fabrics. This method first fibrillates Lyocell fibers under concentrated alkali conditions, and then uses cellulase to remove the split fibrils on the surface of the fabric, thereby reducing the tendency of the fiber to fibrillate during production and use.

Although the above method can prevent the fibrillation of lyocell fiber to a certain extent, it is still difficult to reduce the fibrillation of lyocell woven fabric in the multi-process continuous processing. For the fiber cross-linking treatment method, the fiber needs to go through multiple processes such as spinning, weaving, pre-treatment, printing and dyeing, and finishing after cross-linking, and the friction between fiber and equipment is more, and it is still easy to fibrillate. The resin finishing of lyocell woven fabric is mainly carried out in the finishing process, which is not only difficult to reduce the fibrillation of fabric in pre-treatment and dyeing, but also most of the resins have formaldehyde release. For the cellulase dehairing method, its process is complicated, cost is higher, and the effect between the fiber macromolecular chain is not enhanced, and fibrillation will still occur in subsequent processing and use.

The present invention is based on the processing characteristics of the dyeing process of lyocell woven fabric. On the premise that various performance indicators of the pre-treatment and dyeing of the lyocell fabric meet the requirements, the lyocell woven fabric is subjected to an anti-fibrillation treatment during the dyeing process. This can not only effectively reduce the fibrillation tendency of the fabric during production and use, but also has a short process flow, low cost, and is simple and easy to operate.

Summary of the invention

Aiming at the technical problem that lyocell woven fabrics are prone to fibrillation due to friction under wet, hot and alkaline conditions, the present invention develops a cold pad-batch dyeing process for lyocell woven fabrics that can prevent fibrillation. First, the synergistic effect of amylase and scouring penetrant is used to pre-treat the fabric, which can not only achieve the required whiteness and wool effect, but also shorten the pre-treatment process and reduce the friction of the fabric; the fabric is treated with anti-fibrillation treatment before dyeing to enhance the interaction between the fiber macromolecular chains and prevent the fibrillation of the fabric during the dyeing and use process; the low-temperature and low-friction cold pad-batch dyeing process for lyocell woven fabrics is developed, which can not only prevent the generation of fibrillation, improve the product quality and first-class product rate, but also save energy and protect the environment, and is simple and easy to operate.

The cold pad-batch dyeing process for preventing the fibrillation of lyocell woven fabrics of the present invention comprises the following steps:

(1) preparing a desizing working solution containing 2-14 g/L amylase and 1-5 g/L penetrant, adjusting the pH of the desizing working solution to 4-6, padding the singed Lyocell woven fabric with the desizing working solution, controlling the liquid carrying rate, rolling and stacking at 10-40° C. for a certain period of time, washing with hot water, washing with water at room temperature, and drying;

(2) preparing a solution of an anti-fibrillation treatment agent with a concentration of 5-35 g/L, padding the fabric treated in step (1) with the solution containing the anti-fibrillation treatment agent, controlling the liquid carrying rate, drying, baking, washing, and drying;

(3) preparing a dyeing solution with a concentration of 5-60 g/L of an active dye and a fixing solution with a concentration of 5-40 g/L, mixing the prepared dyeing solution and the fixing solution in a certain ratio to prepare a dyeing working solution, padding the fabric treated in step (2) with the dyeing working solution, controlling the liquid carrying rate, rolling and stacking at a certain temperature for a period of time, washing with hot water, soaping, washing with cold water, and drying.

in:

The penetrant described in step (1) is a non-ionic refined penetrant.

The liquid carrying rate in step (1) is 60-90%, and the stacking time is 1-12 hours.

The liquid carrying rate in step (2) is 60-90%, the baking temperature is 120-180° C., and the baking time is 0.5-5.0 minutes.

The anti-fibrillation treatment agent described in step (2) is one or more of trimethylolpropane-tris (3-aziridinyl propionate), N,N-methylenebisacrylamide, 2,4-diamino-6-diallylamino-1,3,5-triazine, methyl ethyl ketone oxime blocked hexamethylene diisocyanate, isophorone diisocyanate, polyoxyethylene laurate, epichlorohydrin hexamethylenediamine condensate, succinic acid, and 3-hydroxy-1,3,5-pentanetriolic acid anti-fibrillation treatment agent.

The reactive dyes described in step (3) are vinyl sulfone type reactive dyes; including reactive red AS, reactive orange 131, reactive blue 203, reactive blue 238, reactive black 5, reactive red 11, reactive yellow 160, reactive yellow 16, reactive yellow 145, reactive red 194, reactive red 195, reactive red 198, reactive red 227, reactive red 240, reactive red 241, reactive red 261, reactive blue 8, reactive dark blue M-R, reactive blue 194, reactive blue 222, reactive blue 231, reactive blue 19, etc.

The fixing solution in step (3) is LR-01 color fast.

The volume ratio of the dye solution and the color fast color solution in step (3) is 4:1.

The liquid carrying rate in step (3) is 60-90%.

The stacking temperature in step (3) is 10-40° C., and the stacking time is 3-16 hours.

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

(1) The present invention uses an enzyme cold pad-batch desizing process to treat Lyocell woven fabric. Under the synergistic effect of amylase and non-ionic scouring penetrant, there is no need to perform scouring and bleaching scouring and other treatment processes, which shortens the process, saves dyeing and chemical auxiliaries, saves energy and is environmentally friendly, and reduces the friction of the fabric and the risk of fibrillation.

(2) The present invention performs an anti-fibrillation treatment on lyocell woven fabric before dyeing, which has simple process, easy operation and low cost. Since the anti-fibrillation auxiliary agent has multiple reactive groups, the hydroxyl groups on the fiber can be covalently bonded, thereby enhancing the interaction between the fiber macromolecular chains and effectively inhibiting the fibril splitting. For example, anti-fibrillation treatment agents such as dimethyl ketoxime blocked hexamethylene diisocyanate and isophorone diisocyanate are unblocked at high temperature, the blocking groups are removed, the isocyanate groups are exposed, and then addition reactions occur with the hydroxyl groups on different molecular chains on the fiber. The anti-fibrillation treatment agent of trimethylolpropane-tris (3-aziridinyl propionate) can undergo a ring-opening reaction at a relatively low temperature, and then exposes free methyl groups, and the free methyl groups undergo etherification reactions with the hydroxyl groups on different molecular chains on the fiber to form crosslinking. N, N-methylenebisacrylamide, 2, 4-diamino-6-diallylamino-1, 3, 5-triazine and other anti-fibrillation agents are exposed alkenyl groups that react with hydroxyl groups on different molecular chains of the fiber to increase the lateral force between the fiber molecular chains, reduce its lateral swelling performance, and improve the anti-fibrillation ability. The epoxy groups of anti-fibrillation treatment agents such as polyoxyethylene laurate and epichlorohydrin hexamethylenediamine polycondensate open the ring under alkaline conditions to expose the hydroxyl groups, which react with different hydroxyl groups between the lyocell fiber molecular chains to generate ether bonds, increase the lateral force between the fiber molecular chains, and achieve the anti-fibrillation effect. The carboxyl groups of anti-fibrillation treatment agents such as succinic acid and 3-hydroxy-1, 3, 5-pentanetriol react with different hydroxyl groups between the lyocell fiber molecular chains under alkaline conditions to generate ester bonds, increase the lateral force between the fiber molecular chains, and achieve the anti-fibrillation effect.

(3) The present invention adopts a cold pad-batch salt-free dyeing process to dye Lyocell woven fabrics. Compared with the one-phase and two-phase dyeing processes, the friction between the fabric and the equipment is reduced, the fibrillation tendency is reduced, and no salt is used in the dyeing process. The color fixing process does not require steaming, which is energy-saving and environmentally friendly, and has a great application prospect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a SEM image of the fiber surface after treatment in step (1) of Example 1, magnified 3000 times.

Figure 2 is a SEM image of the fiber surface after treatment in step (1) of comparative example 1, magnified 3000 times.

FIG3 is a SEM image of the fiber surface after treatment in step (1) of comparative example 3, magnified 3000 times.

FIG4 is a SEM image of the fiber surface of the Lyocell fabric of Example 1 after the wet rubbing fastness test, magnified 3000 times.

FIG5 is a SEM image of the fiber surface of the Lyocell fabric of Comparative Example 4 after the wet friction fastness test, magnified 3000 times.

FIG6 is a SEM image of the fiber surface of the Lyocell fabric of Comparative Example 5 after the wet friction fastness test, magnified 3000 times.

FIG. 7 is a SEM image of the fiber surface of the Lyocell fabric of Comparative Example 6 after the wet friction fastness test, magnified 3000 times.

Detailed ways

The present invention will be further described below in conjunction with embodiments, but they do not limit the implementation of the present invention.

The TX-908 described in the comparative example of the present invention was purchased from Suzhou Jiesheng New Material Technology Co., Ltd.; the scouring penetrant DX-3060, the powder scouring agent DX-3001A, the liquid scouring agent DX-3001B, the dewaxing scouring agent DX-128, and the hydrogen peroxide stabilizer YJ-558A were purchased from Dongguan Jiahong Silicone Technology Co., Ltd.; the anti-migration agent FM was purchased from Qingdao Dayin Chemical; LR-01 was purchased from Shandong Yellow River Delta Textile Technology Research Institute Co., Ltd. Soap flakes SFJJ were purchased from Dongguan Dongcheng Baifei Testing Instrument Co., Ltd. Cross-linking agent SCA-8325 was purchased from Guangzhou Wanhua New Material Technology Co., Ltd.

Unless otherwise specified, all materials used in the comparative examples and embodiments are commercially available.

The padding equipment used in the examples and comparative examples of the present invention is a Werner Mathis AG type padder, and the stacking tool used is a HWL type oven.

Example 1

A cold pad-batch dyeing process for preventing fibrillation of lyocell woven fabrics comprises the following steps:

(1) double dipping and double padding of a Lyocell woven fabric with a treatment solution containing 12 g/L of LDT-125 amylase and 2 g/L of JFC penetrant, adjusting the pH to 4.5, controlling the liquid carrying rate to 80%, rolling and stacking at 25° C. for 12 hours, washing with hot water twice, then washing with water at room temperature twice, with a bath ratio of 1:50, and drying;

(2) The fabric of step (1) is twice dipped and twice rolled in a solution containing an anti-fibrillation treatment agent N,N-methylenebisacrylamide at a concentration of 15 g/L, and the liquid carrying rate is controlled to be 80%; dried; baked at 125° C. for 2.5 min; washed twice with water at room temperature, washed twice with hot water, washed once with soap (soaping agent 2 g/L, bath ratio 1:30), washed twice with hot water, washed twice with water at room temperature, and dried.

(3) The Lyocell woven fabric treated in step (2) is double dipped and double rolled with a working solution prepared by mixing a 35 g/L reactive red AS dye solution and a 20 g/L LR-01 fixing solution in a volume ratio of 4:1, and the liquid carrying rate is controlled to be 85%. The lyocell woven fabric is rolled and stacked at 25° C. for 10 hours. The stacked lyocell woven fabric is washed twice with hot water, washed once with soap (SFJJ 2 g/L, bath ratio 1:30), washed twice with water at room temperature, with a bath ratio of 1:50, and then dried.

Example 2

A cold pad-batch dyeing process for preventing fibrillation of lyocell woven fabrics comprises the following steps:

(1) double dipping and double padding of a Lyocell woven fabric with a treatment solution containing 2 g/L of LDT-125 amylase and 1 g/L of JFC penetrant, adjusting the pH to 4, controlling the liquid carrying rate to 60%, rolling and stacking at 10° C. for 12 hours, washing with hot water twice, then washing with water at room temperature twice, with a bath ratio of 1:50, and drying;

(2) The fabric of step (1) is twice dipped and twice rolled in a solution containing an anti-fibrillation treatment agent, isophorone diisocyanate, with a concentration of 5 g/L, and the liquid carrying rate is controlled to be 60%; dried; baked at 180° C. for 0.5 min; washed twice with normal temperature water, washed twice with hot water, washed once with soap (soaping agent 2 g/L, bath ratio 1:30), washed twice with hot water, washed twice with normal temperature water, and dried.

(3) The Lyocell woven fabric treated in step (2) is double dipped and double rolled with a working solution of 5 g/L reactive red AS original powder dyeing solution and 5 g/L LR-01 fixing solution in a volume ratio of 4:1, and the liquid carrying rate is controlled to be 60%. The Lyocell woven fabric is rolled and stacked at 10° C. for 16 hours. The stacked Lyocell woven fabric is washed twice with hot water, once with 2g/L soap, and twice with water at room temperature, with a bath ratio of 1:50, and then dried.

Example 3

A cold pad-batch dyeing process for preventing fibrillation of lyocell woven fabrics comprises the following steps:

(1) double dipping and double padding of a Lyocell woven fabric with a treatment solution containing 14 g/L of LDT-125 amylase and 5 g/L of JFC penetrant, adjusting the pH to 6, controlling the liquid carrying rate to 90%, rolling and stacking at 40° C. for 1 hour, washing with hot water twice, then washing with water at room temperature twice, with a bath ratio of 1:50, and drying;

(2) The fabric of step (1) was twice dipped and twice rolled in a solution containing trimethylolpropane-tris[3-(2-methylaziridinyl)propionate] at a concentration of 35 g/L, and the liquid carrying rate was controlled to be 90%; baked at 120° C. for 5 min; washed twice with normal temperature water, washed twice with hot water, washed once with soap (soaping agent 2 g/L, bath ratio 1:30), washed twice with hot water, washed twice with normal temperature water, and dried.

(3) The Lyocell woven fabric treated in step (2) is double dipped and double rolled with a working solution of 60 g/L reactive blue 194 dye solution and 40 g/L LR-01 fixing solution in a volume ratio of 4:1, the liquid carrying rate is controlled to be 90%, and the fabric is rolled and stacked at 40° C. for 3 hours. The stacked Lyocell woven fabric is washed twice with hot water, once with 2 g/L soap, and twice with water at room temperature, with a bath ratio of 1:50, and then dried.

Example 4

A cold pad-batch dyeing process for preventing fibrillation of lyocell woven fabrics comprises the following steps:

(1) double dipping and double padding of a Lyocell woven fabric with a treatment solution containing 12 g/L of LDT-125 amylase and 3 g/L of JFC penetrant, adjusting the pH to 4.5, controlling the liquid carrying rate to 80%, rolling and stacking at 25° C. for 12 hours, washing with hot water twice, then washing with water at room temperature twice, with a bath ratio of 1:50, and drying;

(2) The fabric of step (1) is twice dipped and twice rolled in a solution containing an anti-fibrillation treatment agent, epoxy crosslinking agent SCA-8325, with a concentration of 20 g/L, and the liquid carrying rate is controlled to be 80%; dried; baked at 175°C for 2.5 min; washed twice with water at room temperature, washed twice with hot water, washed once with soap (soaping agent 2 g/L, bath ratio 1:30), washed twice with hot water, washed twice with water at room temperature, and dried.

(3) The Lyocell woven fabric treated in step (2) is double dipped and double rolled with a working solution of 35 g/L reactive red AS original powder dyeing solution and 20 g/L LR-01 fixing solution in a volume ratio of 4:1, and the liquid carrying rate is controlled to be 85%. The Lyocell woven fabric is rolled and stacked at 25° C. for 10 hours. The stacked Lyocell woven fabric is washed twice with hot water, once with 2g/L soap, and twice with water at room temperature, with a bath ratio of 1:50, and then dried.

Example 5

A cold pad-batch dyeing process for preventing fibrillation of lyocell woven fabrics comprises the following steps:

(1) double dipping and double padding of a Lyocell woven fabric with a treatment solution containing 8 g/L of LDT-125 amylase and 4 g/L of JFC penetrant, adjusting the pH to 4.5, controlling the liquid carrying rate to 80%, rolling and stacking at 25° C. for 12 hours, washing with hot water twice, then washing with water at room temperature twice, with a bath ratio of 1:50, and drying;

(2) The fabric of step (1) is twice dipped and twice rolled in a solution containing a fibrillation prevention agent 3-hydroxy-1,3,5-pentanetriolic acid at a concentration of 5 g/L, and the liquid carrying rate is controlled to be 80%; dried; baked at 160°C for 2.5 min; washed twice with water at room temperature, washed twice with hot water, washed once with soap (soaping agent 2 g/L, bath ratio 1:30), washed twice with hot water, washed twice with water at room temperature, and dried.

(3) The Lyocell woven fabric treated in step (2) is double dipped and double rolled with a working solution of 35 g/L reactive red AS original powder dyeing solution and 25 g/L LR-01 fixing solution in a volume ratio of 4:1, and the liquid carrying rate is controlled to be 85%. The lyocell woven fabric is rolled and piled at 25° C. for 10 hours. The piled Lyocell woven fabric is washed twice with hot water, washed once with soap (soaping agent 2 g/L, bath ratio 1:30), washed twice with water at room temperature, with a bath ratio of 1:50, and then dried.

Comparative Example 1

The dyeing process of lyocell woven fabric comprises the following steps:

(1) The Lyocell woven fabric was twice dipped and twice rolled in a treatment solution containing 1 g/L of iron ion chelating agent TX-908, 6 g/L of scouring penetrant DX-36F, 20 g/L of NaOH, and ₇ g/L of 35% _H2O2 , with the liquid carrying rate controlled to 80%, rolled and stacked at 25°C for 15 hours, washed twice with hot water, with a bath ratio of 1:50, and dried;

(2) The Lyocell woven fabric treated in step (1) is double dipped and double rolled with a mixture of 35 g/L reactive red AS dye liquor and 20 g/L LR-01 fixing solution in a volume ratio of 4:1 to prepare a working solution, the liquid carrying rate is controlled to be 85%, and the fabric is rolled and stacked at 25° C. for 10 hours. The stacked Lyocell woven fabric is washed twice with hot water, once with 2 g/L soap, and twice with water at room temperature, with a bath ratio of 1:50, and then dried.

Comparative Example 2

The dyeing process of lyocell woven fabric comprises the following steps:

(1) The Lyocell woven fabric was twice dipped and twice rolled in a treatment solution containing 1 g/L of iron ion chelating agent TX-908, 15 g/L of NaOH, and 2.5 g/L of scouring penetrant DX-3060, with the liquid carrying rate controlled to be 80%, and then stacked in saturated steam at 100° C. for 30 min, and then washed twice with normal temperature water at a bath ratio of 1:50, and then dried;

(2) The Lyocell woven fabric treated in step (1) is double dipped and double rolled with a mixture of 35 g/L reactive red AS dye liquor and 20 g/L LR-01 fixing solution in a volume ratio of 4:1 to prepare a working solution, the liquid carrying rate is controlled to be 85%, and the fabric is rolled and stacked at 25° C. for 10 hours. The stacked Lyocell woven fabric is washed twice with hot water, once with 2g/L soap, and twice with water at room temperature, with a bath ratio of 1:50, and then dried.

Comparative Example 3

The dyeing process of lyocell woven fabric comprises the following steps:

(1) The Lyocell woven fabric was twice dipped and twice rolled in a treatment solution containing 15 g/L of NaOH, the liquid carrying rate was controlled to be 80%, and the fabric was piled up in saturated steam at 100° C., the steaming time was controlled to be 30 min, and the fabric was washed with hot water twice, the bath ratio was 1:50, and the fabric was dried;

(2) the Lyocell woven fabric treated in step (1) is double dipped and double rolled in a treatment solution containing 1 g/L of ion chelating agent TX-908, 10 g/L of powder scouring agent DX-3001A, 2 g/L of liquid scouring agent DX-3001B, 1 g/L of dewaxing scouring agent DX-128, 4 g/L of hydrogen peroxide stabilizer YJ-558A, and ₆ g/L of 35% _H2O2 , the pH value is controlled at 10.75±0.25, the liquid carrying rate is controlled at 80%, the fabric is stacked in saturated steam at 100°C, the steaming time is controlled at 20 min, hot water washing is performed twice, the bath ratio is 1:50, and drying is performed;

(3) The Lyocell woven fabric treated in step (2) is double dipped and double rolled with a working solution of 35 g/L reactive red AS original powder dyeing solution and 20 g/L LR-01 fixing solution in a volume ratio of 4:1, and the liquid carrying rate is controlled to be 85%. The Lyocell woven fabric is rolled and stacked at 25° C. for 10 hours. The stacked Lyocell woven fabric is washed twice with hot water, once with 2g/L soap, and twice with water at room temperature, with a bath ratio of 1:50, and then dried.

Comparative Example 4

The dyeing process of lyocell woven fabric comprises the following steps:

(1) double dipping and double padding of a Lyocell woven fabric with a treatment solution containing 12 g/L of LDT-125 amylase and 3 g/L of JFC penetrant, adjusting the pH to 4.5, controlling the liquid carrying rate to 80%, rolling and stacking at 25° C. for 12 hours, washing with hot water 3 times, then washing with water at room temperature 2 times, with a bath ratio of 1:50, and drying;

(2) The Lyocell woven fabric treated in step (1) was twice dipped and twice rolled in a working solution containing 35 g/L of active red AS powder, 15 g/L of anti-migration agent FM, 20 g/L of NaHCO ₃ , and 50 g/L of NaCl, with the liquid carrying rate controlled at 70%; dried; steamed at 100° C. for 5 min; washed with water at room temperature 4 times with a bath ratio of 50:1; washed with soap 2 times with a bath ratio of 50:1; washed with hot water 2 times with a bath ratio of 50:1; washed with water at room temperature once with a bath ratio of 50:1; and dried.

Comparative Example 5

The dyeing process of lyocell woven fabric comprises the following steps:

(1) double dipping and double padding of a Lyocell woven fabric with a treatment solution containing 12 g/L of LDT-125 amylase and 3 g/L of JFC penetrant, adjusting the pH to 4.5, controlling the liquid carrying rate to 80%, rolling and stacking at 25° C. for 12 hours, washing with hot water twice, then washing with water at room temperature twice, with a bath ratio of 1:50, and drying;

(2) The Lyocell woven fabric treated in step (1) is twice dipped and twice rolled in a working solution containing 35 g/L of active red AS powder and 15 g/L of anti-migration agent FM, and the liquid carrying rate is controlled to be 70%; dried; then dipped and once rolled in a fixing solution containing 20 g/L of _Na2CO3 , ₂ g/L of NaOH, and 200 g/L of NaCl, and the liquid carrying rate is controlled to be 100%, steamed at 100°C for 5 min; washed with water at room temperature for 4 times, with a bath ratio of 50:1; washed with soap for 2 times, with a bath ratio of 50:1; washed with hot water for 2 times, with a bath ratio of 50:1; washed with water at room temperature once, with a bath ratio of 50:1; and dried.

Comparative Example 6

The dyeing process of lyocell woven fabric comprises the following steps:

(1) double dipping and double padding of a Lyocell woven fabric with a treatment solution containing 12 g/L of LDT-125 amylase and 3 g/L of JFC penetrant, adjusting the pH to 4.5, controlling the liquid carrying rate to 80%, rolling and stacking at 25° C. for 12 hours, washing with hot water twice, then washing with water at room temperature twice, with a bath ratio of 1:50, and drying;

(2) The Lyocell woven fabric treated in step (1) is double dipped and double rolled with a mixture of 35 g/L reactive red AS dye liquor and 20 g/L LR-01 fixing solution in a volume ratio of 4:1 to prepare a working solution, the liquid carrying rate is controlled to be 85%, and the fabric is rolled and stacked at 25° C. for 10 hours. The stacked Lyocell woven fabric is washed twice with hot water at room temperature, once with 2 g/L soap, and twice with water at room temperature, with a bath ratio of 1:50, and then dried.

CIE whiteness is based on GB/T17644-2008. The fabric sample is folded to a light-proof state, and tested using a Datacolor colorimeter under standard light source D65 and 10° viewing angle. The average value is taken for 10 points, and the whiteness is calculated according to the Hunter formula: W _h = 100-[(100-L ^* ) ² + a ^*2 + b ^*2]1/2

Table 1 Whiteness of Lyocell fabrics with different pre-treatment processes

Fabric pre-treatment process CIE whiteness W _h Grey cloth 81 Example 1 Lyocell woven fabric after step (1) treatment 91 Example 2 Lyocell woven fabric after step (1) treatment 90 Example 3 Lyocell woven fabric after step (1) treatment 90 Comparative Example 1 Lyocell woven fabric after treatment in step (1) 89 Comparative Example 2 Lyocell woven fabric after treatment in step (1) 85 Comparative Example 3 Lyocell woven fabric after treatment in step (2) 91

As can be seen from the above table, the whiteness of the cold pad-batch enzyme desizing pretreatment process provided by the present invention is equivalent to that of the desizing, boiling and bleaching one-bath process and the alkali desizing, boiling and bleaching process, and is better than that of the traditional alkali desizing and scouring process.

Use Datacolor 850 spectrophotometer to test 10 points of the dyed fabric at random under 10° viewing angle, D65 light source, and 30mm colorimetric aperture. Fold the fabric to an opaque state and measure the apparent color depth (K/S value) of the dyed fabric sample at the maximum absorption wavelength 10 times.

Table 2 K/S values of Lyocell fabrics with different dyeing processes

It can be seen from the above table that the cold pad-batch salt-free dyeing process using vinyl sulfone type reactive dyes has a better color depth than the traditional one-phase and two-phase processes.

Wet rubbing fastness: Use a rubbing color fastness meter to test the rubbing fastness of dyed fabrics in accordance with GB/T3920-2008 "Textiles - Tests for Color Fastness - Color Fastness to Rubbing".

Wet rubbing fastness Example 1 4-5 Example 2 4 Example 3 4-5 Example 4 4-5 Example 5 4-5 Comparative Example 1 3-4 Comparative Example 2 3-4 Comparative Example 3 3 Comparative Example 4 3-4 Comparative Example 5 3-4 Comparative Example 6 3-4

The lyocell woven fabric treated in step (1) of Example 1, the lyocell woven fabric treated in step (1) of Comparative Example 1, and the lyocell woven fabric treated in step (1) of Comparative Example 3 were magnified 3000 times by SEM, and the difference in the degree of fibrillation caused by different pre-treatment processes on the fiber surface was observed, as shown in Figures 1, 2, and 3. As can be seen from the figure, the enzyme cold pad-batch desizing process used in the present invention has a lower fibrillation level than the cold pad-batch alkali desizing, refining, bleaching, one-bath process and the traditional alkali desizing, bleaching, two-bath process.

The wet rubbing fastness of the lyocell fabrics after finishing and dyeing in Example 1, Comparative Example 4, Comparative Example 5 and Comparative Example 6 was tested, and the wet rubbing lyocell fabrics were magnified 3000 times by SEM to observe the difference in the anti-fibrillation ability of the fabric surface, as shown in Figures 4, 5, 6 and 7. As can be seen from the figure, the vinyl sulfone reactive dye cold pad-batch salt-free dyeing process used in the present invention has better anti-fibrillation ability than the vinyl sulfone reactive dye one-phase dyeing process and the vinyl sulfone reactive dye two-phase dyeing process, while the anti-fibrillation ability of the lyocell woven fabric without anti-fibrillation finishing process is still inferior to the solution provided by the present invention.

Claims (6)

1. A cold pad-batch dyeing process for preventing fibrillation of lyocell woven fabrics, characterized in that it comprises the following steps: (1) preparing a desizing working solution containing 2-14 g/L amylase and 1-5 g/L penetrant, adjusting the pH of the desizing working solution to 4-6, padding the singed Lyocell woven fabric with the desizing working solution, controlling the liquid carrying rate, rolling and stacking, washing with hot water, washing with water at room temperature, and drying; (2) preparing a solution of an anti-fibrillation treatment agent with a concentration of 5-35 g/L, padding the fabric treated in step (1) with the solution containing the anti-fibrillation treatment agent, controlling the liquid carrying rate, drying, baking, washing, and drying; (3) preparing a dye liquor with a concentration of 5-60 g/L of an active dye and a fixing solution with a concentration of 5-40 g/L, dyeing a lyocell woven fabric by a cold pad-batch salt-free dyeing process, uniformly mixing the prepared dye liquor and the fixing solution in a certain proportion to prepare a dyeing working solution, padding the fabric treated in step (2) with the dyeing working solution, controlling the liquid carrying rate, rolling and stacking, and then washing with hot water, soaping, and cold water, and drying; The liquid carrying rate in step (1) is 60-90%; The stacking temperature in step (1) is 10-40° C. and the stacking time is 1-12 hours; The anti-fibrillation treatment agent in step (2) is one or more of trimethylolpropane-tris (3-aziridinyl propionate), N,N-methylenebisacrylamide, 2,4-diamino-6-diallylamino-1,3,5-triazine, methyl ethyl ketone oxime blocked hexamethylene diisocyanate, isophorone diisocyanate, polyoxyethylene laurate, epichlorohydrin hexamethylenediamine polycondensate, succinic acid, and 3-hydroxy-1,3,5-pentanetriolic acid anti-fibrillation treatment agent; The reactive dye described in step (3) is a vinyl sulfone type reactive dye. 2. The cold pad-batch dyeing process for preventing fibrillation of lyocell woven fabric according to claim 1, characterized in that the penetrant in step (1) is a non-ionic scouring penetrant. 3. The cold pad-batch dyeing process for preventing fibrillation of lyocell woven fabric according to claim 1, characterized in that the liquid carrying rate in step (2) is 60-90%. 4. The cold pad-batch dyeing process for preventing fibrillation of lyocell woven fabric according to claim 1, characterized in that the baking temperature in step (2) is 120-180°C and the baking time is 0.5-5.0 minutes. 5. The cold pad-batch dyeing process for preventing fibrillation of lyocell woven fabric according to claim 1, characterized in that the liquid carrying rate in step (3) is 60-90%. 6. The cold pad-batch dyeing process for preventing fibrillation of lyocell woven fabric according to claim 1, characterized in that the stacking temperature in step (3) is 10-40°C and the stacking time is 3-16 hours.