CN114775281B - Preparation method of Porel jean-like fabric based on weft hydrophobic treatment - Google Patents

Abstract

The invention relates to a preparation method of Porel jean-like fabric based on weft hydrophobic treatment, which uses elastic core spun yarn containing hydrophobic Porel fibers as weft yarns, uses yarns composed of Porel fibers as warp yarns, weaves the weft yarns and the warp yarns into the fabric, and then dyes the fabric by adopting cationic dye to obtain Porel jean-like fabric, wherein the content of hydrophobic Porel fibers in the elastic core spun yarn containing hydrophobic Porel fibers is 92wt%, the hydrophobic Porel fibers are Porel fibers subjected to hydrophobic treatment, and the cationic dye is a cationic dye capable of dyeing Porel fibers and simultaneously incapable of dyeing hydrophobic Porel fibers. The product prepared by the method has good moisture absorption and moisture transfer performance, the fabric has high color fastness and bright color, has the style of imitated jeans, and can be suitable for the imitated jeans in spring and summer.

Description

A preparation method of Porel imitation denim fabric based on weft yarn hydrophobic treatment

Technical Field

The invention belongs to the technical field of fabrics and relates to a method for preparing a Porel imitation denim fabric based on weft yarn hydrophobic treatment.

Background technique

Porel fiber is a modified polyester staple fiber with a capillary waist-shaped inner cavity structure. The hydrophilic group and flexible group in the structure, and the cotton-like cavity structure used in spinning make the clothing made of Porel fiber not only have the feel of mercerized cotton, but also comfortable to wear, easy to dye, high fastness and good moisture absorption and moisture conduction properties. The fiber capillary inner cavity structure makes the fiber fluffy, making the fabric both warm and light; the rich flexible groups in the fiber macromolecules can also reduce the fiber rigid modulus, so that the fabric feels softer and is not easy to pilling after friction and rubbing. The fabric of Porel fiber has good moisture absorption and quick drying, moisture absorption and heat generation, warmth retention and quick drying characteristics.

Imitation denim fabrics are mainly prepared through two methods: yarn dyeing and fabric dyeing. The former is mostly cellulose fibers such as cotton, viscose and Tencel; the latter is often dyed with dyes and paints. At present, dye dyeing often uses reactive dyes to dye cellulose fibers, but dyeing often consumes a lot of dyes, inorganic salts and water, and the utilization rate of dyes is below 80%, and a lot of dye wastewater is discharged. In order to reduce the discharge of dyes and shorten the process flow, paint dyeing is used to prepare imitation denim fabrics. Although this method can reduce dye wastewater, the technical application is not widespread. When the fabric formed by the treated yarn is dyed again, the utilization rate of the dye can be improved, the color fastness of the fabric can be improved, the process is simple, the process is short, and less wastewater is discharged. After finishing, the fabric can form fabrics with different properties, which are widely used.

In the prior art, methods for preparing imitation denim fabrics by using warp yarns and weft yarns with the same raw materials or main raw materials through weaving and then dyeing include:

(1) using dyes to dye warp and weft yarns with the same raw materials or main raw materials to prepare imitation denim fabrics by dyeing after weaving, the dye is an indigo dye, and the imitation denim style cannot be formed directly after dyeing, and sand washing is required to show the imitation denim style. A large amount of dyes, auxiliaries and water are consumed in the sand washing process;

(2) Imitation denim fabrics are prepared by dyeing with paint using warp and weft yarns with the same raw materials or main raw materials after weaving. The process flow of paint dyeing is: fabric pretreatment → paint roller dyeing → baking → sand washing → soft finishing. The key to the formation of imitation denim style during paint dyeing is sand washing. Although this method can reduce dye wastewater, the technology is not widely used.

If the sand washing process can be omitted, it will be very meaningful to prepare imitation denim fabrics by using warp and weft yarns made entirely or mainly of Porel fibers through a post-weaving dyeing method.

Summary of the invention

The purpose of the invention is to solve the problems existing in the prior art and to provide a method for preparing a Porel imitation denim fabric based on weft yarn hydrophobic treatment.

To achieve the above object, the technical solution adopted by the present invention is as follows:

The invention discloses a preparation method of a Porel imitation denim fabric based on a hydrophobic treatment of weft yarns. The method comprises the following steps: using an elastic core-spun yarn containing hydrophobic Porel fibers as weft yarns and a yarn composed of Porel fibers as warp yarns, weaving the weft yarns and the warp yarns into fabrics, and then dyeing the fabrics with cationic dyes to obtain the Porel imitation denim fabrics. The content of hydrophobic Porel fibers in the elastic core-spun yarn containing hydrophobic Porel fibers is 92wt%, the hydrophobic Porel fibers are hydrophobically treated Porel fibers, and the cationic dyes are cationic dyes that can dye Porel fibers but cannot dye hydrophobic Porel fibers. The cationic dyes that dye the Porel fibers should have some characteristics, such as a monoazo structure of a heterocyclic system and a compatibility value of about 3, such as cationic blue X-GRRL, cationic red 2GL and cationic dye brilliant blue RL. The cationic dyes have poor affinity for the hydrophobically treated Porel fibers and cannot dye them, so dyeing of the hydrophobically treated Porel fibers can be avoided.

The invention can prepare the imitation denim fabric by dyeing with dyes using weft yarns and warp yarns whose main raw material is Porel fiber through weaving and dyeing without sand washing. Although all the raw materials of the warp yarns are Porel fiber and the main raw material of the weft yarns is Porel fiber, the weft yarns are hydrophobic and difficult to dye during the dyeing process. During the dyeing process, since the weft yarns are hydrophobic and the warp yarns are hydrophilic, the weft yarns are lighter in color and the warp yarns are darker in color. The warp floating points (front side) are colored and the weft floating points (back side) are left blank. The fabric has the style of denim fabric. At the same time, thanks to the difference in hydrophilicity and hydrophobicity between the front and back sides of the fabric (the back side has discontinuous hydrophobic points and the front side has certain hydrophilicity) and the hollow structure of the Porel fiber, the fabric has good moisture absorption and perspiration wicking performance.

As the preferred technical solution:

As described above, a method for preparing a Porel imitation denim fabric based on a hydrophobic treatment of weft yarns, the preparation process of the elastic core-spun yarn containing hydrophobic Porel fibers is as follows: on a ring spinning machine, a spandex filament with a thickness of 40D is fed into the front roller, and a Porel fiber with a thickness of 308-350dtex is fed into the rear roller, the spandex filament and the Porel fiber are combined, and then twisted in a twisting triangle area to obtain an elastic core-spun yarn with a twist coefficient of 300-330, and then hydrophobic treatment is performed to obtain the elastic core-spun yarn containing the hydrophobic Porel fibers, wherein the stretching multiples of the spandex filaments are 3.5-4, the stretching multiples of the rear area are 1.1-1.2, and the pre-stretching multiples are 4-5.

As described above, a method for preparing Porel imitation denim fabric based on weft yarn hydrophobic treatment, the process of hydrophobic treatment of the elastic core-spun yarn is: after the elastic core-spun yarn is immersed in a hydrophobic finishing liquid at a temperature of 30°C for 30 to 45 minutes, it is pre-baked at 85 to 95°C for 3 to 5 minutes, and then baked at 110 to 120°C for 1 to 2 minutes, wherein the hydrophobic finishing liquid is obtained by dissolving a hydrophobic finishing agent and a cross-linking agent in water and then adjusting the pH value to 5 to 6.

As described above, a preparation method of Porel imitation denim fabric based on weft hydrophobic treatment, the concentration of the hydrophobic finishing agent in the hydrophobic finishing liquid is 40-80 g/L, the concentration of the cross-linking agent is 1-3 g/L, and the mass ratio of the elastic core-spun yarn to the hydrophobic finishing liquid during immersion is 1:20-40; the hydrophobic finishing agent is a silicone hydrophobic agent such as polydimethylsiloxane, polysiloxane-modified water-based polyurethane, silicone-modified polyacrylate, etc.; the cross-linking agent is etherified hydroxymethyl melamine, ethylene oxide-based, citric acid or polycarboxylic acid.

As described above, a preparation method of Porel imitation denim fabric based on weft hydrophobic treatment, the specifications of the weft yarn are 10-15S/1, 92P/8SP, the specifications of the warp yarn are 10-15S/1, 100%P, and the thickness of the Porel fiber in the warp yarn is 310-340dtex.

The preparation method of Porel imitation denim fabric based on weft hydrophobic treatment as described above has a total tightness of 55-70%, an interlacing frequency of 0.2-0.4, a weave structure of 3 up and 1 down/left oblique or 2 up and 1 down/left oblique, and a warp and weft density of 60×44-60×50.

In the preparation method of Porel imitation denim fabric based on weft yarn hydrophobic treatment as described above, before dyeing, the back of the fabric is subjected to hydrophobic coating by screen printing; coating the back of the fabric can improve the hydrophobicity of the back of the fabric, and not coating the front of the fabric can retain the hydrophilicity of the front of the fabric, thereby increasing the difference in hydrophilicity between the two sides of the fabric and thereby improving the moisture absorption and perspiration wicking performance of the fabric.

As described above, a preparation method of Porel imitation denim fabric based on weft hydrophobic treatment, the process of hydrophobic coating finishing is: first, a hydrophobic finishing agent is mixed with a sodium alginate paste with a concentration of 50-60wt% to obtain a color paste with a hydrophobic finishing agent concentration of 2-12wt%, and then the color paste is finished on the back of the fabric by screen printing, and then the fabric is pre-baked at 80-90°C for 2-4min, and then baked at 120-125°C for 3-4min, and finally washed with water to remove the sodium alginate on the back of the fabric.

In the method for preparing the Porel imitation denim fabric based on the hydrophobic treatment of the weft yarn as described above, the hydrophobic finishing agent is polydimethylsiloxane, polysiloxane-modified waterborne polyurethane or silicone-modified polyacrylate.

The preparation method of Porel imitation denim fabric based on weft yarn hydrophobic treatment as described above, the dyeing process is: first, the fabric is added to the dye solution at a temperature of 30°C, then the temperature is increased to 60-70°C at a heating rate of 2-2.5°C/min and then kept warm for 25-30min, and finally the temperature is increased to 85-95°C at a heating rate of 0.5-1°C/min and then kept warm for 45-60min; the dye solution is obtained by adding cationic dye, KFS and sodium sulfate to water and then adjusting the pH value of the system to 5-6, the mass fraction of the cationic dye in the dye solution is 1-4% owf, the concentration of KFS is 0.5-1g/L, and the concentration of sodium sulfate is 2g/L; the dyeing bath ratio is 1:15-30.

The preparation method of Porel imitation denim fabric based on weft hydrophobic treatment as described above is as follows: after dyeing, reduction cleaning is performed; the cleaning solution is composed of 2-3 g/L of hydrosulfite, 0.5-1 g/L of sodium hydroxide and the remainder of water; the reduction cleaning temperature is 75-85°C, the time is 10-15 min, and the bath ratio is 1:15-30.

The preparation method of the Porel imitation denim fabric based on the weft hydrophobic treatment as described above, the water absorption rate of the Porel imitation denim fabric based on the weft hydrophobic treatment is 165-230%, the water absorption rate is 20-35%/s, the one-way transfer index is 145-200, the vertical wicking height is 60-85mm, the dyeing rate is 80-94%, the rubbing fastness is above level 3, and the soap washing fastness is above level 3. The test methods of water absorption rate, water absorption rate, one-way transfer index and vertical wicking height are all based on GB/T21655.2-2019 "Evaluation of Moisture Absorption and Quick-drying of Textiles Part 2: Dynamic Moisture Transfer Method", FZ/T 01071-2008 "Test Method for Capillary Effect of Textiles" and water absorption rate and drip diffusion time are based on GB/T 21655.1-2008 "Evaluation of Moisture Absorption and Quick-drying of Textiles Part 1: Single Item Combination Test Method", and the test method of rubbing fastness is based on GB/T 3920-2008 "Textiles - Tests for colour fastness - Colour fastness to rubbing", the test method for fastness to washing with soap refers to GB/T 3921-2008 "Textiles - Tests for colour fastness - Colour fastness to washing with soap".

Beneficial effects:

(1) The weft yarn and the reverse side of the fabric in the preparation method of the present invention are hydrophobically finished, so that the two sides of the fabric have greater differences;

(2) In the preparation method of the present invention, cationic dyes are used to dye Porel fibers, and the hollowness of the prepared Porel fibers has good moisture retention and high utilization rate of the dyes.

(3) The Porel imitation denim fabric with hydrophobic weft yarn of the present invention has warp floating point (front) color, weft floating point (white space, imitation denim style;

(4) The Porel imitation denim fabric with hydrophobic weft yarn of the present invention has discontinuous hydrophobic points on the back and a certain degree of hydrophilicity on the front, has good moisture absorption and perspiration wicking properties, can provide thermal and wet comfort, and is suitable for the development of spring and summer imitation denim fabrics;

(5) The Porel imitation denim fabric with hydrophobic weft yarn of the present invention has good moisture absorption and moisture conduction properties, and the fabric has bright color and good color fastness, and can be applied to spring and summer imitation denim fabrics.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

Example 1

A method for preparing Porel imitation denim fabric based on weft yarn hydrophobic treatment, the specific steps are as follows:

(1) Preparation of raw materials;

The weft yarn is an elastic core-spun yarn containing hydrophobic Porel fiber, the content of the hydrophobic Porel fiber is 92wt%, and the specification of the weft yarn is 10S/1, 92P/8SP. The preparation method is as follows: on a ring spinning machine, a spandex filament with a thickness of 40D is fed into a front roller, and a Porel fiber with a thickness of 308dtex is fed into a rear roller, the spandex filament and the Porel fiber are combined, twisted in a twisting triangle area to obtain an elastic core-spun yarn with a twist coefficient of 300, and then hydrophobic treatment is performed to obtain the elastic core-spun yarn containing the hydrophobic Porel fiber, wherein the drafting multiple of the spandex filament is 3.5, the drafting multiple of the rear area is 1.1, and the pre-drafting multiple is 4;

The process of hydrophobic treatment of elastic core-spun yarn is as follows: soak the elastic core-spun yarn in a hydrophobic finishing liquid at a temperature of 30°C for 30 minutes, pre-bake at 85°C for 3 minutes, and then bake at 110°C for 2 minutes, wherein the hydrophobic finishing liquid is obtained by dissolving a hydrophobic finishing agent and a cross-linking agent in water and then adjusting the pH value to 5; the concentration of the hydrophobic finishing agent in the hydrophobic finishing liquid is 40g/L, the concentration of the cross-linking agent is 3g/L, and the mass ratio of the elastic core-spun yarn to the hydrophobic finishing liquid during immersion is 1:20; the hydrophobic finishing agent is polydimethylsiloxane (JZH-203); the cross-linking agent is etherified hydroxymethyl melamine;

The warp yarn is composed of Porel fiber with a thickness of 310 dtex, and the specification of the warp yarn is 15S/1, 100% P;

(2) Weaving;

Weaving weft and warp yarns into fabric;

The total tightness of the fabric is 55%, the interlacing frequency of the fabric is 0.2, the fabric structure is 3 up and 1 down/left oblique, and the warp and weft density is 60×44;

(3) Hydrophobic coating finishing;

First, polydimethylsiloxane (JZH-203) and sodium alginate paste with a concentration of 50wt% are mixed to obtain a color paste with a hydrophobic finishing agent concentration of 2wt%, and then the color paste is finished on the reverse side of the fabric obtained in step (2) by screen printing, and then the fabric is pre-baked at 80°C for 4 minutes, and then baked at 120°C for 4 minutes, and finally washed with water to remove the sodium alginate on the reverse side of the fabric;

(4) Staining;

First, the fabric treated with the hydrophobic coating in step (3) is added to the dyeing solution at a temperature of 30°C, then the temperature is increased to 60°C at a heating rate of 2°C/min and then kept warm for 30 minutes, and finally the temperature is increased to 95°C at a heating rate of 0.5°C/min and then kept warm for 45 minutes; the dyeing solution is obtained by adding cationic blue X-GRRL, KFS and sodium sulfate to water and then adjusting the pH value of the system to 5, the mass fraction of cationic blue X-GRRL in the dyeing solution is 1% owf, the concentration of KFS is 0.5g/L, and the concentration of sodium sulfate is 2g/L; the bath ratio of dyeing is 1:15;

(5) Reduction cleaning;

After dyeing, the fabric obtained in step (4) is subjected to reduction cleaning to obtain Porel imitation denim fabric based on weft yarn hydrophobic treatment; wherein the cleaning solution consists of 2 g/L of hydrophobic powder, 0.5 g/L of sodium hydroxide and the remainder of water; the reduction cleaning temperature is 75° C., the time is 15 min, and the bath ratio is 1:15.

The water absorption rate of the prepared Porel imitation denim fabric based on weft hydrophobic treatment is 190%, the water absorption rate is 25%/s, the one-way transfer index is 160, the vertical wicking height is 70mm, the dyeing rate is 90%, the friction fastness is level 3-4, and the soap washing fastness is level 3-4.

Example 2

A method for preparing Porel imitation denim fabric based on weft yarn hydrophobic treatment, the specific steps are as follows:

(1) Preparation of raw materials;

The weft yarn is an elastic core-spun yarn containing hydrophobic Porel fiber, the content of the hydrophobic Porel fiber is 92wt%, and the specification of the weft yarn is 10S/1, 92P/8SP. The preparation method is as follows: on a ring spinning machine, a spandex filament with a thickness of 40D is fed into a front roller, and a Porel fiber with a thickness of 315dtex is fed into a rear roller, the spandex filament and the Porel fiber are combined, twisted in a twisting triangle area to obtain an elastic core-spun yarn with a twist coefficient of 310, and then hydrophobic treatment is performed to obtain the elastic core-spun yarn containing the hydrophobic Porel fiber, wherein the drafting multiple of the spandex filament is 3.7, the drafting multiple of the rear area is 1.1, and the pre-drafting multiple is 4;

The process of hydrophobic treatment of the elastic core-spun yarn is as follows: the elastic core-spun yarn is immersed in a hydrophobic finishing liquid at a temperature of 30°C for 33 minutes, pre-baked at 87°C for 3 minutes, and then baked at 112°C for 2 minutes, wherein the hydrophobic finishing liquid is obtained by dissolving a hydrophobic finishing agent and a cross-linking agent in water and then adjusting the pH value to 5; the concentration of the hydrophobic finishing agent in the hydrophobic finishing liquid is 50g/L, the concentration of the cross-linking agent is 3g/L, and the mass ratio of the elastic core-spun yarn to the hydrophobic finishing liquid during immersion is 1:25; the hydrophobic finishing agent is polysiloxane-modified waterborne polyurethane (SPU); the cross-linking agent is an epoxy silane cross-linking agent (brand number XR-500);

The warp yarn is composed of Porel fiber with a thickness of 320 dtex, and the specification of the warp yarn is 12S/1, 100% P;

(2) Weaving;

Weaving weft and warp yarns into fabric;

The total tightness of the fabric is 58%, the interlacing frequency of the fabric is 0.2, the fabric structure is 3 up and 1 down/left oblique, and the warp and weft density is 60×44;

(3) Hydrophobic coating finishing;

First, polysiloxane-modified waterborne polyurethane (SPU) is mixed with sodium alginate paste with a concentration of 52 wt% to obtain a color paste with a hydrophobic finishing agent concentration of 4 wt%, and then the color paste is finished on the reverse side of the fabric obtained in step (2) by screen printing, and then the fabric is pre-baked at 82° C. for 4 min, and then baked at 122° C. for 4 min, and finally washed with water to remove the sodium alginate on the reverse side of the fabric;

(4) Staining;

First, the fabric treated with the hydrophobic coating in step (3) is added to the dyeing solution at a temperature of 30°C, then the temperature is increased to 64°C at a heating rate of 2.1°C/min and then kept warm for 28 minutes, and finally the temperature is increased to 93°C at a heating rate of 0.6°C/min and then kept warm for 48 minutes; the dyeing solution is obtained by adding cationic red 2GL, KFS and sodium sulfate to water and then adjusting the pH value of the system to 5, the mass fraction of cationic red 2GL in the dyeing solution is 1.5% owf, the concentration of KFS is 0.6g/L, and the concentration of sodium sulfate is 2g/L; the bath ratio of dyeing is 1:20;

(5) Reduction cleaning;

After dyeing, the fabric obtained in step (4) is subjected to reduction cleaning to obtain Porel imitation denim fabric based on weft yarn hydrophobic treatment; wherein the cleaning solution consists of 2 g/L of hydrophobic powder, 0.6 g/L of sodium hydroxide and the remainder of water; the reduction cleaning temperature is 77° C., the time is 14 min, and the bath ratio is 1:18.

The water absorption rate of the prepared Porel imitation denim fabric based on weft hydrophobic treatment is 195%, the water absorption rate is 28%/s, the one-way transfer index is 165, the vertical wicking height is 73mm, the dyeing rate is 91%, the friction fastness is level 3-4, and the soap washing fastness is level 3-4.

Example 3

A method for preparing Porel imitation denim fabric based on weft yarn hydrophobic treatment, the specific steps are as follows:

(1) Preparation of raw materials;

The weft yarn is an elastic core-spun yarn containing hydrophobic Porel fiber, the content of the hydrophobic Porel fiber is 92wt%, and the specification of the weft yarn is 12S/1, 92P/8SP. The preparation method is as follows: on a ring spinning machine, a spandex filament with a thickness of 40D is fed into a front roller, and a Porel fiber with a thickness of 320dtex is fed into a rear roller, the spandex filament and the Porel fiber are combined, twisted in a twisting triangle area to obtain an elastic core-spun yarn with a twist coefficient of 315, and then hydrophobic treatment is performed to obtain the elastic core-spun yarn containing the hydrophobic Porel fiber, wherein the drafting multiple of the spandex filament is 3.8, the drafting multiple of the rear area is 1.2, and the pre-drafting multiple is 5;

The process of hydrophobic treatment of elastic core-spun yarn is as follows: soak the elastic core-spun yarn in a hydrophobic finishing liquid at a temperature of 30°C for 36 minutes, pre-bake at 89°C for 4 minutes, and then bake at 114°C for 2 minutes, wherein the hydrophobic finishing liquid is obtained by dissolving a hydrophobic finishing agent and a cross-linking agent in water and then adjusting the pH value to 5; the concentration of the hydrophobic finishing agent in the hydrophobic finishing liquid is 60g/L, the concentration of the cross-linking agent is 2g/L, and the mass ratio of the elastic core-spun yarn to the hydrophobic finishing liquid during immersion is 1:30; the hydrophobic finishing agent is silicone-modified polyacrylate (PUA); the cross-linking agent is citric acid;

The warp yarn is composed of Porel fiber with a thickness of 320 dtex, and the specification of the warp yarn is 12S/1, 100% P;

(2) Weaving;

Weaving weft and warp yarns into fabric;

The total tightness of the fabric is 62%, the interlacing frequency of the fabric is 0.3, the fabric structure is 3 up and 1 down/left oblique, and the warp and weft density is 60×48;

(3) Hydrophobic coating finishing;

First, a silicone-modified polyacrylate (PUA) is mixed with a sodium alginate paste having a concentration of 54 wt% to obtain a color paste having a hydrophobic finishing agent concentration of 6 wt%, and then the color paste is applied to the reverse side of the fabric obtained in step (2) by screen printing, and then the fabric is pre-baked at 84°C for 3 min, and then baked at 124°C for 4 min, and finally washed with water to remove the sodium alginate on the reverse side of the fabric;

(4) Staining;

First, the fabric treated with the hydrophobic coating in step (3) is added to the dye solution at a temperature of 30°C, then the temperature is increased to 66°C at a heating rate of 2.2°C/min and then kept warm for 26 minutes, and finally the temperature is increased to 90°C at a heating rate of 0.7°C/min and then kept warm for 50 minutes; the dye solution is obtained by adding cationic dye brilliant blue RL, KFS and sodium sulfate to water and then adjusting the pH value of the system to 5, the mass fraction of the cationic dye brilliant blue RL in the dye solution is 2% owf, the concentration of KFS is 0.7g/L, and the concentration of sodium sulfate is 2g/L; the dyeing bath ratio is 1:23;

(5) Reduction cleaning;

After dyeing, the fabric obtained in step (4) is subjected to reduction cleaning to obtain Porel imitation denim fabric based on weft yarn hydrophobic treatment; wherein the cleaning solution consists of 3 g/L of hydrophobic powder, 0.7 g/L of sodium hydroxide and the remainder of water; the reduction cleaning temperature is 79° C., the time is 13 min, and the bath ratio is 1:21.

The water absorption rate of the prepared Porel imitation denim fabric based on weft yarn hydrophobic treatment is 210%, the water absorption rate is 30%/s, the one-way transfer index is 170, the vertical wicking height is 78mm, the dyeing rate is 87%, the friction fastness is level 3-4, and the soap washing fastness is level 3-4.

Example 4

A method for preparing Porel imitation denim fabric based on weft yarn hydrophobic treatment, the specific steps are as follows:

(1) Preparation of raw materials;

The weft yarn is an elastic core-spun yarn containing hydrophobic Porel fiber, the content of the hydrophobic Porel fiber is 92wt%, and the specification of the weft yarn is 12S/1, 92P/8SP. The preparation method is as follows: on a ring spinning machine, a spandex filament with a thickness of 40D is fed into a front roller, and a Porel fiber with a thickness of 330dtex is fed into a rear roller, the spandex filament and the Porel fiber are combined, twisted in a twisting triangle area to obtain an elastic core-spun yarn with a twist coefficient of 320, and then hydrophobic treatment is performed to obtain the elastic core-spun yarn containing the hydrophobic Porel fiber, wherein the drafting multiple of the spandex filament is 3.9, the drafting multiple of the rear area is 1.2, and the pre-drafting multiple is 5;

The process of hydrophobic treatment of elastic core-spun yarn is as follows: soak the elastic core-spun yarn in a hydrophobic finishing liquid at a temperature of 30°C for 40 minutes, pre-bake at 91°C for 4 minutes, and then bake at 116°C for 1 minute, wherein the hydrophobic finishing liquid is obtained by dissolving a hydrophobic finishing agent and a cross-linking agent in water and then adjusting the pH value to 6; the concentration of the hydrophobic finishing agent in the hydrophobic finishing liquid is 70g/L, the concentration of the cross-linking agent is 1g/L, and the mass ratio of the elastic core-spun yarn to the hydrophobic finishing liquid during immersion is 1:35; the hydrophobic finishing agent is polydimethylsiloxane (JZH-203); the cross-linking agent is polycarboxylic acid (CA);

The warp yarn is composed of Porel fiber with a thickness of 330 dtex, and the specification of the warp yarn is 10S/1, 100% P;

(2) Weaving;

Weaving weft and warp yarns into fabric;

The total tightness of the fabric is 67%, the interlacing frequency of the fabric is 0.3, the fabric structure is 2 up and 1 down/left oblique, and the warp and weft density is 60×50;

(3) Hydrophobic coating finishing;

First, polydimethylsiloxane (JZH-203) and sodium alginate paste with a concentration of 57wt% are mixed to obtain a color paste with a hydrophobic finishing agent concentration of 8wt%, and then the color paste is finished on the reverse side of the fabric obtained in step (2) by screen printing, and then the fabric is pre-baked at 88°C for 3min, and then baked at 125°C for 3min, and finally washed with water to remove the sodium alginate on the reverse side of the fabric;

(4) Staining;

First, the fabric treated with the hydrophobic coating in step (3) is added to the dyeing solution at a temperature of 30°C, then the temperature is increased to 68°C at a heating rate of 2.4°C/min and then kept warm for 25 minutes, and finally the temperature is increased to 88°C at a heating rate of 0.9°C/min and then kept warm for 55 minutes; the dyeing solution is obtained by adding cationic blue X-GRRL, KFS and sodium sulfate to water and then adjusting the pH value of the system to 6, the mass fraction of cationic blue X-GRRL in the dyeing solution is 3% owf, the concentration of KFS is 0.8g/L, and the concentration of sodium sulfate is 2g/L; the bath ratio of dyeing is 1:27;

(5) Reduction cleaning;

After dyeing, the fabric obtained in step (4) is subjected to reduction cleaning to obtain Porel imitation denim fabric based on weft yarn hydrophobic treatment; wherein the cleaning solution consists of 3 g/L of hydrophobic powder, 0.9 g/L of sodium hydroxide and the remainder of water; the reduction cleaning temperature is 82° C., the time is 12 min, and the bath ratio is 1:25.

The water absorption rate of the prepared Porel imitation denim fabric based on weft yarn hydrophobic treatment is 230%, the water absorption rate is 35%/s, the one-way transfer index is 200, the vertical wicking height is 85mm, the dyeing rate is 86%, the friction fastness is level 3-4, and the soap washing fastness is level 3-4.

Example 5

A method for preparing Porel imitation denim fabric based on weft yarn hydrophobic treatment, the specific steps are as follows:

(1) Preparation of raw materials;

The weft yarn is an elastic core-spun yarn containing hydrophobic Porel fiber, the content of the hydrophobic Porel fiber is 92wt%, and the specification of the weft yarn is 15S/1, 92P/8SP. The preparation method is as follows: on a ring spinning machine, a spandex filament with a thickness of 40D is fed into a front roller, and a Porel fiber with a thickness of 350dtex is fed into a rear roller, the spandex filament and the Porel fiber are combined, twisted in a twisting triangle area to obtain an elastic core-spun yarn with a twist coefficient of 330, and then hydrophobic treatment is performed to obtain the elastic core-spun yarn containing the hydrophobic Porel fiber, wherein the drafting multiple of the spandex filament is 4, the drafting multiple of the rear area is 1.2, and the pre-drafting multiple is 5;

The process of hydrophobic treatment of elastic core-spun yarn is as follows: soak the elastic core-spun yarn in a hydrophobic finishing liquid at a temperature of 30°C for 45 minutes, pre-bake at 95°C for 5 minutes, and then bake at 120°C for 1 minute, wherein the hydrophobic finishing liquid is obtained by dissolving a hydrophobic finishing agent and a cross-linking agent in water and then adjusting the pH value to 6; the concentration of the hydrophobic finishing agent in the hydrophobic finishing liquid is 80g/L, the concentration of the cross-linking agent is 1g/L, and the mass ratio of the elastic core-spun yarn to the hydrophobic finishing liquid during immersion is 1:40; the hydrophobic finishing agent is polysiloxane-modified waterborne polyurethane (SPU); the cross-linking agent is etherified hydroxymethyl melamine;

The warp yarn is composed of Porel fiber with a thickness of 340 dtex, and the specification of the warp yarn is 10S/1, 100% P;

(2) Weaving;

Weaving weft and warp yarns into fabric;

The total tightness of the fabric is 70%, the interlacing frequency of the fabric is 0.4, the fabric structure is 2 up and 1 down/left oblique, and the warp and weft density is 60×50;

(3) Hydrophobic coating finishing;

First, polysiloxane-modified waterborne polyurethane (SPU) is mixed with sodium alginate paste with a concentration of 60 wt% to obtain a color paste with a hydrophobic finishing agent concentration of 12 wt%, and then the color paste is finished on the reverse side of the fabric obtained in step (2) by screen printing, and then the fabric is pre-baked at 90° C. for 2 min, and then baked at 125° C. for 3 min, and finally washed with water to remove the sodium alginate on the reverse side of the fabric;

(4) Staining;

First, the fabric treated with the hydrophobic coating in step (3) is added to the dyeing solution at a temperature of 30°C, then the temperature is increased to 70°C at a heating rate of 2.5°C/min and then kept warm for 25 minutes, and finally the temperature is increased to 85°C at a heating rate of 1°C/min and then kept warm for 60 minutes; the dyeing solution is obtained by adding cationic red 2GL, KFS and sodium sulfate to water and then adjusting the pH value of the system to 6, the mass fraction of cationic red 2GL in the dyeing solution is 4% owf, the concentration of KFS is 1g/L, and the concentration of sodium sulfate is 2g/L; the bath ratio of dyeing is 1:30;

(5) Reduction cleaning;

After dyeing, the fabric obtained in step (4) is subjected to reduction cleaning to obtain Porel imitation denim fabric based on weft yarn hydrophobic treatment; wherein the cleaning solution consists of 3 g/L of hydrophobic powder, 1 g/L of sodium hydroxide and the remainder of water; the reduction cleaning temperature is 85° C., the time is 10 min, and the bath ratio is 1:30.

The water absorption rate of the prepared Porel imitation denim fabric based on weft hydrophobic treatment is 220%, the water absorption rate is 28%/s, the one-way transfer index is 180, the vertical wicking height is 80mm, the dyeing rate is 88%, the friction fastness is level 3-4, and the soap washing fastness is level 3-4.

Example 6

A method for preparing Porel imitation denim fabric based on weft hydrophobic treatment is basically the same as Example 1, except that Example 6 does not have step (3) (i.e., no hydrophobic coating treatment).

The water absorption rate of the Porel imitation denim fabric based on weft yarn hydrophobic treatment is 165%, the water absorption rate of the soaked surface is 20%/s, the one-way transfer index is 145, the vertical wicking height is 60mm, the dyeing rate is 90%, the friction fastness is level 3-4, and the soap washing fastness is level 3-4.

Example 7

A method for preparing Porel imitation denim fabric based on weft hydrophobic treatment is basically the same as Example 2, except that Example 6 does not have step (3) (i.e., no hydrophobic coating treatment).

The water absorption of the Porel imitation denim fabric based on weft hydrophobic treatment is 171%, the water absorption rate is 23%/s, the one-way transfer index is 152, the vertical wicking height is 64mm, the dyeing rate is 92%, the friction fastness is level 3-4, and the soap washing fastness is level 3-4.

Claims (7)

1. A method for preparing a Porel imitation denim fabric based on a hydrophobic treatment of a weft yarn, characterized in that an elastic core-spun yarn containing hydrophobic Porel fiber is used as a weft yarn, and a yarn composed of Porel fiber is used as a warp yarn. After the weft yarn and the warp yarn are woven into a fabric, a hydrophobic coating is firstly applied to the reverse side of the fabric by screen printing, and then the fabric is dyed with a cationic dye to obtain the Porel imitation denim fabric, wherein the content of the hydrophobic Porel fiber in the elastic core-spun yarn containing the hydrophobic Porel fiber is 92wt%, the hydrophobic Porel fiber is a Porel fiber that has been subjected to a hydrophobic treatment, and the cationic dye is a cationic dye that can dye the Porel fiber but cannot dye the hydrophobic Porel fiber; The process of hydrophobic coating finishing is as follows: firstly, a hydrophobic finishing agent is mixed with a sodium alginate paste with a concentration of 50-60wt% to obtain a color paste with a hydrophobic finishing agent concentration of 2-12wt%, and then the color paste is finished on the reverse side of the fabric by screen printing, and then the fabric is pre-baked at 80-90°C for 2-4min, and then baked at 120-125°C for 3-4min, and finally washed with water to remove the sodium alginate on the reverse side of the fabric; The hydrophobic finishing agent used in the hydrophobic coating finishing is polydimethylsiloxane, polysiloxane-modified waterborne polyurethane or silicone-modified polyacrylate; The dyeing process is as follows: first, the fabric is added to the dye solution at a temperature of 30°C, then the temperature is increased to 60~70°C at a heating rate of 2~2.5°C/min and then kept warm for 25~30min, and finally the temperature is increased to 85~95°C at a heating rate of 0.5~1°C/min and then kept warm for 45~60min; the dye solution is obtained by adding cationic dye, KFS and sodium sulfate to water and then adjusting the pH value of the system to 5~6, the mass fraction of the cationic dye in the dye solution is 1~4%owf, the concentration of KFS is 0.5~1g/L, and the concentration of sodium sulfate is 2g/L; the dyeing bath ratio is 1:15~30. 2. A method for preparing a Porel imitation denim fabric based on hydrophobic treatment of weft yarn according to claim 1, characterized in that the preparation process of the elastic core-spun yarn containing hydrophobic Porel fiber is as follows: on a ring spinning machine, a spandex filament with a thickness of 40D is fed into the front roller, and a Porel fiber with a thickness of 308-350dtex is fed into the rear roller, and the spandex filament and the Porel fiber are combined and twisted in a twisting triangle area to obtain an elastic core-spun yarn with a twist coefficient of 300-330, and then a hydrophobic treatment is performed to obtain the elastic core-spun yarn containing the hydrophobic Porel fiber, wherein the drafting multiple of the spandex filament is 3.5-4, the drafting multiple of the rear area is 1.1-1.2, and the pre-drafting multiple is 4-5. 3. A method for preparing a Porel imitation denim fabric based on weft yarn hydrophobic treatment according to claim 2, characterized in that the process of hydrophobic treatment of the elastic core-spun yarn is: after the elastic core-spun yarn is immersed in a hydrophobic finishing liquid at a temperature of 30°C for 30-45 minutes, it is pre-baked at 85-95°C for 3-5 minutes, and then baked at 110-120°C for 1-2 minutes, wherein the hydrophobic finishing liquid is obtained by dissolving a hydrophobic finishing agent and a cross-linking agent in water and then adjusting the pH value to 5-6. 4. A method for preparing a Porel imitation denim fabric based on weft hydrophobic treatment according to claim 3, characterized in that the concentration of the hydrophobic finishing agent in the hydrophobic finishing liquid is 40-80 g/L, the concentration of the cross-linking agent is 1-3 g/L, and the mass ratio of the elastic core-spun yarn to the hydrophobic finishing liquid during immersion is 1:20-40; the hydrophobic finishing agent in the hydrophobic finishing liquid is polydimethylsiloxane, polysiloxane-modified waterborne polyurethane or silicone-modified polyacrylate; the cross-linking agent is etherified hydroxymethyl melamine, ethylene oxide-based, citric acid or polycarboxylic acid. 5. The method for preparing a Porel imitation denim fabric based on weft yarn hydrophobic treatment according to claim 3, characterized in that the specification of the weft yarn is 10~15S/1, 92P/8SP, the specification of the warp yarn is 10~15S/1, 100%P, and the thickness of the Porel fiber in the warp yarn is 310~340dtex. 6. A method for preparing a Porel imitation denim fabric based on weft yarn hydrophobic treatment according to claim 5, characterized in that the total tightness of the fabric is 55-70%, the interlacing frequency of the tissue is 0.2-0.4, the tissue structure is 3 up and 1 down/left oblique or 2 up and 1 down/left oblique, and the warp and weft density is 60×44-60×50. 7. A method for preparing a Porel imitation denim fabric based on weft hydrophobic treatment according to claim 1, characterized in that the Porel imitation denim fabric based on weft hydrophobic treatment has a water absorption rate of 165-230%, a water absorption rate of 20-35%/s, a one-way transfer index of 145-200, a vertical wicking height of 60-85 mm, a dye uptake rate of 80-94%, a friction fastness of more than grade 3, and a soap washing fastness of more than grade 3.