Preparation method of high-breathable food service fabric

Abstract

The application relates to the technical field of textile fabrics, in particular to a preparation method of a high-breath food clothing fabric, which comprises the preparation of yarns, weaving, dyeing and finishing and post-finishing; the fabric prepared by the above process has good antistatic property, washing resistance and high breathability.

Description

Technical Field

[0001] This invention relates to the field of textile fabric technology, and in particular to a method for preparing a highly breathable food clothing fabric. Background Technology

[0002] With the continuous development of society, comfort has become an indispensable indicator for textiles, and breathability is a key indicator for evaluating the comfort of textiles. In the food apparel sector, fabrics must possess certain barrier and antistatic properties while also being resistant to industrial washing and able to withstand frequent washing and friction. However, in existing technologies, to improve the fabric's ability to block liquid contaminants (such as water and oil) (i.e., water repellency), high-density fabrics or dense coating processes are typically used. However, this often severely clogs the fabric's pores, leading to a sharp decrease in breathability and moisture permeability. Conversely, if a thin or porous structure is used simply to improve breathability, its physical strength and the bonding strength between the coating and the substrate will be insufficient, making it difficult for the fabric's industrial washing resistance and mechanical durability to meet the high-frequency cleaning requirements of the food processing environment. Therefore, developing a food apparel fabric that combines high water repellency, high breathability and moisture permeability, antistatic properties, and industrial washing resistance has become an urgent problem to be solved. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for preparing a highly breathable food clothing fabric, which addresses the shortcomings of the prior art. The fabric prepared by this method has good antistatic properties, washability, and high breathability.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0005] A method for preparing a highly breathable food clothing fabric includes yarn preparation, weaving, dyeing and finishing, and post-finishing.

[0006] The yarn preparation is as follows: the first warp yarn is a twisted 150D DTY filament single yarn; the second warp yarn is a composite yarn made by twisting 75D DTY filament and 75D alkali-soluble yarn together; the third warp yarn is a multifunctional composite yarn made by twisting 75D DTY filament, 75D alkali-soluble yarn and 20D conductive yarn together; the first weft yarn is a twisted 150D DTY filament single yarn, and the second weft yarn is a composite yarn made by twisting 75D DTY filament and 75D alkali-soluble yarn together; the twist of the first, second, and third warp yarns and the first and second weft yarns is 500-1000 twists / m.

[0007] The post-processing includes the following steps:

[0008] (1) Immerse the dyed and finished fabric in the pretreatment solution, control the treatment temperature and treatment time, and then dry and bake to obtain the pretreated fabric for use.

[0009] (2) Take the pre-treated fabric described in step (1), apply the foaming slurry to the surface of the fabric after mechanical foaming, and control the coating thickness; first, pre-curing treatment is carried out at a temperature not exceeding 85°C, then post-curing treatment is carried out at a temperature not exceeding 150°C, and finally plasma treatment is carried out to obtain a surface-activated porous structure fabric.

[0010] (3) Within 30 minutes after the plasma treatment is completed, take the porous structure fabric activated in step (2), dilute the coating concentrate and spray it onto the fabric multiple times, control the coating thickness and drying temperature, and bake it after spraying to obtain a highly breathable food clothing fabric.

[0011] As an improved technical solution, the pretreatment solution in step (1) is a diluted working solution, wherein the concentration of nano zinc oxide is 1-3 g / L; the pretreatment solution is diluted from a concentrated solution containing the following components by weight percentage: 10-30% nano zinc oxide, 1-5% polymeric dispersant, 0.5-2% sodium citrate, 1-3% silane coupling agent, and the remainder is solvent; the treatment temperature is 50-70℃, and the treatment time is 10-30 min.

[0012] As an improved technical solution, the foaming slurry in step (2) comprises the following components by weight percentage: 55-65% aqueous polyurethane dispersion (solid content 40-50%), 10-15% polycarbonate polyol dispersion (solid content 40-50%), 5-8% calcium carbonate, 0.5-2% external crosslinking agent, 0.5-2% foam stabilizer, 0.2-0.5% wetting and dispersing agent, 0.5-1.5% thickener, and the remainder is water; the foaming slurry is mechanically stirred to form foam with bubbles of 50-200μm in diameter, and then coated on the surface of the fabric.

[0013] As an improved technical solution, in step (2), the wet film coating thickness is controlled to be 0.13-0.26 mm; the temperature of the pre-curing treatment is 75-85℃ and the time of the pre-curing treatment is 1-2 min; the temperature of the post-curing treatment is 120-150℃ and the time of the post-curing treatment is 3-5 min; the power of the plasma treatment is 50-60 W and the treatment time is 30-45 s.

[0014] As an improved technical solution, the coating concentrate in step (3) comprises the following components by weight percentage: 50-65% silicone acrylic resin, 10-20% ethyl polyacrylate, 0.8-2% methacryloyloxypropyltrimethoxysilane, 1-3% isocyanate crosslinking agent, 0.2-0.5% wetting and leveling agent, 0.1-0.3% defoamer, and the balance being water.

[0015] As an improved technical solution, the coating thickness in step (3) is less than 5 μm and the drying temperature is 150-160℃.

[0016] As an improved technical solution, the weaving adopts a double-warp, double-layer structure. The first warp yarn is the outer warp, which interweaves with the first weft yarn to form the outer layer; the second and third warp yarns are the inner warp, which together interweave with the second weft yarn to form the inner layer; the ratio of the number of the first, second, and third warp yarns is 90:89:1; and the ratio of the number of the first and second weft yarns is 1:1.

[0017] As an improved technical solution, the dyeing and finishing process includes pretreatment, dyeing and posttreatment. In the pretreatment, when reducing the amount of alkali, the initial concentration of sodium hydroxide is 3-5 g / L, the bath ratio is controlled at 1:8-12, the temperature is increased to 120-130℃ at a rate of 0.5-1.5℃ / min, and the treatment time is 25-35 min.

[0018] After adopting the above technical solution, the beneficial effects of the present invention are:

[0019] The present invention discloses a method for preparing food-grade clothing fabric. In the yarn preparation, the second warp contains 75D alkali-soluble yarn, and the third warp contains 75D alkali-soluble yarn and 20D conductive yarn. During the alkali reduction treatment in the dyeing and finishing stage, after the alkali-soluble yarn is effectively dissolved, the internal space of the yarn originally occupied by the alkali-soluble yarn is released, forming a large number of micro-physical pores in the original composite yarn position. These pores constitute air-permeable channels in the fabric body, significantly improving the fabric's breathability. Furthermore, the conductive yarn can dissipate static electricity from the human body, giving the fabric antistatic properties.

[0020] The weaving process employs a double-warp, double-layer structure, controlling the ratio of the first, second, and third warp yarns to 90:89:1; and the ratio of the first and second weft yarns to 1:1. This ensures a balanced and tight bond between the outer layer (high strength and abrasion resistance) and the inner layer (functional comfort), resulting in a smooth fabric that is not easily deformed or curled.

[0021] During finishing, the fabric is first immersed in a pretreatment solution containing nano-zinc oxide. Because the preceding alkali reduction process has created microscopic etched pits on the fiber surface, the nano-zinc oxide particles can embed themselves in these pits, forming a physical anchor. Simultaneously, the silane coupling agent in the pretreatment solution optimizes the dispersibility of the nano-zinc oxide and assists its adhesion to the fiber surface. Through its surface effect and potential slow-release of zinc ions, the nano-zinc oxide exhibits good inhibitory effects against common microorganisms such as Staphylococcus aureus and Escherichia coli. Through the synergistic effect of physical integration and chemical assistance, relatively durable antibacterial properties can be achieved.

[0022] The pretreated fabric is then coated with a foaming slurry layer. After curing, the foam coating forms a three-dimensional interconnected porous structure, providing efficient escape channels for water vapor molecules. Subsequently, the surface of the foam layer undergoes plasma treatment, which effectively removes surface organic contaminants and introduces a small number of reactive groups (such as amine and imine groups) as "reaction anchors" for subsequent chemical crosslinking. The isocyanate crosslinking agent and silane coupling agent in the ultra-thin water-repellent coating solution can form chemical bridges with these reactive groups. Simultaneously, through low surface tension and wetting, they penetrate into the pores of the foam layer surface, forming a continuous and smooth closed film at the pore openings. The thickness of this closed film can be controlled at the micrometer level, preserving the breathable channels within the internal porous structure while forming a complete water-repellent interface on the outermost surface of the fabric, thus achieving a coexistence of high water repellency and high breathability. Furthermore, the resin in the foam layer and coating slurry significantly improves the interlayer bonding strength through a dual effect of physical anchoring and chemical bonding.

[0023] The durability of the aforementioned functional components stems from a multi-layered synergistic mechanism: the micropores on the fiber surface formed by alkali reduction etching provide physical anchoring points for nano-zinc oxide; the foam coating further encapsulates the functional particles, forming a three-dimensional protective layer; the reactive groups introduced by plasma treatment form chemical bridges with the coating crosslinking agent; and the conductive fibers and microporous structure constitute an overall skeleton, enhancing dimensional stability. Testing shows that after more than 50 standard industrial washes, the fabric's main functions (breathability, moisture permeability, antibacterial properties, and antistatic properties) exhibit a degradation rate of less than 25%, demonstrating excellent functional durability, significantly extending the product's effective lifespan, and reducing the total cost of ownership. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] Example 1

[0026] A method for preparing a highly breathable food clothing fabric includes yarn preparation, weaving, dyeing and finishing, and post-finishing.

[0027] The yarn preparation is as follows: the first warp yarn is a twisted 150D DTY filament (specifically, 150D DTY polyester filament) single yarn; the second warp yarn is a composite yarn formed by plying 75D DTY filament (specifically, polyester DTY filament) and 75D alkali-soluble filament (alkali-soluble polyester filament) using a plying machine and then twisting it using a twisting machine; the third warp yarn is a multi-functional composite yarn formed by plying 75D DTY filament, 75D alkali-soluble filament (alkali-soluble polyester filament), and 20D conductive filament (carbon black composite conductive polyester filament) using a plying machine and then twisting it using a twisting machine; the first weft yarn is a twisted 150D DTY filament single yarn, and the second weft yarn is a composite yarn formed by plying 75D DTY filament and 75D alkali-soluble filament (alkali-soluble polyester filament) using a plying machine and then twisting it using a twisting machine; the twist of the first, second, and third warp yarns and the first and second weft yarns are 500 twists / m respectively.

[0028] The weaving employs a double-warp, double-layer structure. The first warp yarn is the outer warp, interwoven with the first weft yarn to form the outer layer (specifically, when the first weft yarn is introduced, only the first warp yarn is raised according to the outer weave diagram to form the outer shed, while the second and third warp yarns are all located in the lower layer and do not participate in the interweaving; after introduction, the weft is beaten in to form the outer layer of the fabric). The second and third warp yarns are the inner warp, interwoven together with the second weft yarn to form the inner layer (specifically, when the second weft yarn is introduced, only the second and third warp yarns are raised according to the inner weave diagram to form the inner shed, while the first warp yarn is all located in the upper layer and does not participate in the interweaving; after introduction, the weft is beaten in to form the inner layer of the fabric). The ratio of the number of the first, second, and third warp yarns is 90:89:1. Calculations show that when the finished width is 160cm, the average spacing of the third warp yarns is 3.6cm; the ratio of the number of the first and second weft yarns is 1:1.

[0029] Dyeing and finishing include the following steps:

[0030] Pretreatment (alkali reduction): After desizing and scouring the greige fabric, alkali reduction treatment is performed (initial sodium hydroxide concentration is 3g / L, bath ratio is controlled at 1:8, temperature is increased to 120℃ at 0.5℃ / min, treatment time is 25min; actual measurement shows that the overall alkali reduction rate of the fabric is about 18%; this reduction effect mainly comes from two contributions: the alkali-soluble polyester filaments in the inner layer yarns are completely dissolved during the alkali treatment, forming permanent microporous channels inside the fabric; at the same time, the surface of the ordinary polyester fibers in the outer and inner layers is moderately etched, the fibers are refined, and micro-pits are formed on the surface. The two work together to give the fabric high air permeability while enhancing the physical anchoring effect between the fibers and the subsequent coating), and the fabric is thoroughly washed with water until neutral after treatment.

[0031] Dyeing: A high-temperature, high-pressure dyeing machine is used, with 1.5% (owf) of environmentally friendly disperse dye (model: deep three primary colors) and matching auxiliaries added. The temperature is increased to 130℃ at a rate of 1.5℃ / min and held for 45 minutes. After dyeing, the temperature is slowly lowered.

[0032] Post-treatment: Perform reduction cleaning (80℃, 15min), then hot water wash, cold water wash, and finally set at 170℃ for 45 seconds to obtain the dyed and finished fabric.

[0033] The post-processing includes the following steps:

[0034] (1) Immerse the dyed and finished fabric in the pretreatment solution (which is a diluted working solution, wherein the concentration of nano zinc oxide is 1 g / L, and the pretreatment solution is prepared by diluting a concentrated solution containing the following components by weight percentage: 10% nano zinc oxide, 1% polymeric dispersant, 0.5% sodium citrate, 1% silane coupling agent, and the remainder is solvent, and the pH is adjusted to 5 with dilute acetic acid; the polymeric dispersant is a polycarboxylate dispersant, specifically Weifang Dadong Dispersant 1610; the silane coupling agent is specifically KH550, and the solvent is deionized water and ethanol in a volume ratio of 9:1). Proportional mixing; Preparation method of concentrated solution: Mix nano zinc oxide, polymeric dispersant, sodium citrate and 2 / 3 volume of solvent, grind with a sand mill until the median particle size D50 of the slurry is ≤100nm to obtain a stable nano zinc oxide concentrated slurry; then dilute and hydrolyze the silane coupling agent with the remaining solvent, and slowly add it to the above concentrated slurry under stirring conditions, and stir evenly to obtain the pretreated concentrated solution. Control the treatment temperature at 50℃, treat for 10min, pre-dry at 100℃ for 3min to allow the fabric to dry initially, and then bake at 150℃ for 2min to obtain the pretreated fabric for use.

[0035] (2) Take the pretreated fabric from step (1) and add the foaming slurry (which includes the following components by weight percentage: 55% aqueous polyurethane dispersion (45% solid content), 10% polycarbonate polyol dispersion (40% solid content), 5% calcium carbonate (particle size ≤ 2μm), 0.5% external crosslinking agent, 0.5% foam stabilizer, 0.2% wetting and dispersing agent, 0.8% thickener, and the remainder is water; wherein the aqueous polyurethane dispersion is an aqueous dispersion of aliphatic polyurethane, which does not contain free isocyanate groups, specifically Covestro Bayhydrol). ®UH2888; the specific model of the polycarbonate polyol dispersion is PU623A; the external crosslinking agent is polycarbodiimide with a solid content of 40%, such as Shanghai Youen Chemical UN-557; the foam stabilizer is L-580; the wetting and dispersing agent is DISPERBYK-2015; the thickener is ASE type) are added into a mechanical foaming machine, and air is mixed in through high-speed shearing. The stirring speed is adjusted to 800 rpm, and the foaming ratio is controlled to 1:2.5 to obtain a foaming slurry with a micron-sized bubble diameter of 50-100μm. This slurry is then coated on the surface of the fabric, and the wet film coating thickness is controlled to be 0.13mm. The fabric is first pre-cured at 75℃ for 1 min, and then post-cured at 120℃ for 3 min. Finally, a dielectric barrier discharge (DBD) plasma device is used with nitrogen (gas flow rate controlled at 5L / min) as the working gas for 30s (power of 50w) to obtain a surface-activated porous structure fabric.

[0036] (3) Within 15 minutes after the plasma treatment is completed, take the porous structure fabric activated in step (2), and dilute the coating concentrate (which includes the following components by weight percentage: 50% silicone acrylic resin, 10% polyethyl acrylate, 0.8% methacryloyloxypropyltrimethoxysilane, 1% isocyanate crosslinking agent, 0.2% wetting and leveling agent, 0.1% defoamer, and the remainder is water; the wetting and leveling agent is BYK-346, and the defoamer is BYK-028; the isocyanate crosslinking agent is packaged separately from the other components and mixed when used) with deionized water, adjust the solid content of the working liquid to 12%, stir thoroughly, let it stand to defoam, and then spray it multiple times with an ultrasonic nozzle (spraying pressure controlled at 0.1MPa, spraying distance at 15cm, and single spraying amount at 4g / m). 2 After each coat of spray, the coating is dried in the oven at 70°C for 20 seconds (this process is repeated 4 times). The coating thickness is controlled to be 2μm. After spraying, the coating is pre-baked at 80°C for 1 minute to allow it to level and react initially. Then, it is baked at 150°C for 3 minutes to obtain a highly breathable food-grade fabric.

[0037] Example 2

[0038] A method for preparing a highly breathable food clothing fabric includes yarn preparation, weaving, dyeing and finishing, and post-finishing.

[0039] The yarn preparation is as follows: the first warp yarn is a twisted 150D DTY filament single yarn (same as in Example 1); the second warp yarn is a composite yarn made by twisting 75D DTY filament (same as in Example 1) and 75D alkali-soluble yarn (same as in Example 1); the third warp yarn is a multifunctional composite yarn made by twisting 75D DTY filament, 75D alkali-soluble yarn and 20D conductive yarn (same as in Example 1); the first weft yarn is a twisted 150D DTY filament single yarn; the second weft yarn is a composite yarn made by twisting 75D DTY filament and 75D alkali-soluble yarn; the twist of the first, second, and third warp yarns and the first and second weft yarns are 800 twists / m respectively.

[0040] The weaving adopts a double-warp, double-layer structure. The first warp yarn is the outer warp, which interweaves with the first weft yarn to form the outer layer; the second and third warp yarns are the inner warp, which together interweave with the second weft yarn to form the inner layer; the ratio of the number of the first, second, and third warp yarns is 90:89:1; the ratio of the number of the first and second weft yarns is 1:1.

[0041] Dyeing and finishing include the following steps:

[0042] Pretreatment (alkali reduction): After desizing and scouring the greige fabric, alkali reduction treatment is carried out (the initial concentration of sodium hydroxide is 4g / L, the bath ratio is controlled at 1:10, the temperature is increased to 125℃ at 1℃ / min, and the treatment time is 30min; according to actual measurement, the overall alkali reduction rate of the fabric is about 22%). After treatment, the fabric is thoroughly washed with water until neutral.

[0043] Dyeing: A high-temperature, high-pressure dyeing machine is used, with 1.5% (owf) of environmentally friendly disperse dye (model: deep three primary colors) and matching auxiliaries added. The temperature is increased to 130℃ at a rate of 1.5℃ / min and held for 45 minutes. After dyeing, the temperature is slowly lowered.

[0044] Post-treatment: Perform reduction cleaning (80℃, 15min), then hot water wash, cold water wash, and finally set at 170℃ for 45 seconds to obtain the dyed and finished fabric.

[0045] The post-processing includes the following steps:

[0046] (1) The dyed and finished fabric is immersed in a pretreatment solution (which is a diluted working solution, wherein the concentration of nano zinc oxide is 2 g / L, and the pretreatment solution is prepared by diluting a concentrated solution containing the following weight percentage components: 20% nano zinc oxide, 3% polymeric dispersant, 1.2% sodium citrate, 2% silane coupling agent, and the remainder is solvent, and the pH is adjusted to 5.5 with dilute acetic acid; the silane coupling agent is KH550, and the solvent is deionized water and ethanol mixed in a volume ratio of 9:1; the preparation method of the concentrated solution and the polymeric dispersant are the same as in Example 1), the treatment temperature is controlled at 60°C, and after treatment for 20 min, it is pre-dried at 100°C for 3 min to make the fabric initially dry, and then baked at 150°C for 2 min to obtain the pretreated fabric for use;

[0047] (2) Take the pretreated fabric from step (1) and add the foaming slurry (which includes the following components by weight percentage: 60% aqueous polyurethane dispersion (45% solid content), 13% polycarbonate polyol dispersion (45% solid content), 8% calcium carbonate (particle size ≤ 2μm), 1.2% external crosslinking agent, 1% foam stabilizer, 0.6% wetting and dispersing agent, 1.2% thickener, and the remainder is water; wherein the aqueous polyurethane dispersion is an aqueous dispersion of aliphatic polyurethane, which does not contain free isocyanate groups, specifically Covestro Bayhydrol). ® UH 2888; the specific model of the polycarbonate polyol dispersion is PU623A; the external crosslinking agent is polycarbodiimide with a solid content of 40%, such as Shanghai Youen Chemical UN-557; the foam stabilizer is L-580, the wetting and dispersing agent is DISPERBYK-2015, and the thickener is ASE type) are put into a mechanical foaming machine, and air is mixed in by high-speed shearing. The stirring speed is adjusted to 1000 rpm, and the foaming ratio is controlled at 1:3.0 to obtain a foaming slurry with a micron-sized bubble diameter of 100-150μm. This slurry is then coated on the surface of the fabric, and the wet film coating thickness is controlled at 0.2mm. The fabric is first pre-cured at 80℃ for 1.5min, and then post-cured at 135℃ for 4min. Finally, a dielectric barrier discharge (DBD) plasma device is used with nitrogen (gas flow rate controlled at 8L / min) as the working gas for 38s (power of 55w) to obtain a surface-activated porous structure fabric.

[0048] (3) Within 15 minutes after the plasma treatment is completed, take the porous structure fabric activated in step (2), and dilute the coating concentrate (which includes the following components by weight percentage: 58% silicone acrylic resin, 15% polyethyl acrylate, 1.3% methacryloyloxypropyltrimethoxysilane, 2% isocyanate crosslinking agent, 0.35% wetting and leveling agent, 0.2% defoamer, and the remainder is water; the wetting and leveling agent is BYK-346, and the defoamer is BYK-028; the isocyanate crosslinking agent is packaged separately from the other components and mixed when used) with deionized water, adjust the solid content of the working liquid to 15%, stir thoroughly, let it stand to remove bubbles, and then spray it multiple times with an ultrasonic nozzle (spraying pressure controlled at 0.2MPa, spraying distance of 20cm, and single spray amount of 5g / m). 2 After each coat of coating, the coating is dried in the oven at 80°C for 30 seconds (this process is repeated 4 times). The coating thickness is controlled to be 3μm. After the coating is finished, it is pre-dried at 90°C for 1.5 minutes to allow the coating to level and react initially. Then it is baked at 160°C for 3 minutes to obtain a highly breathable food-grade fabric.

[0049] Example 3

[0050] A method for preparing a highly breathable food clothing fabric includes yarn preparation, weaving, dyeing and finishing, and post-finishing.

[0051] The yarn preparation is as follows: the first warp yarn is a twisted 150D DTY filament single yarn; the second warp yarn is a composite yarn made by twisting 75D DTY filament (same as in Example 1) and 75D alkali-soluble yarn (same as in Example 1); the third warp yarn is a multifunctional composite yarn made by twisting 75D DTY filament, 75D alkali-soluble yarn and 20D conductive yarn (same as in Example 1); the first weft yarn is a twisted 150D DTY filament single yarn; the second weft yarn is a composite yarn made by twisting 75D DTY filament and 75D alkali-soluble yarn; the twist of the first, second, and third warp yarns and the first and second weft yarns are 1000 twists / m respectively.

[0052] The weaving adopts a double-warp, double-layer structure. The first warp yarn is the outer warp, which interweaves with the first weft yarn to form the outer layer; the second and third warp yarns are the inner warp, which together interweave with the second weft yarn to form the inner layer; the ratio of the number of the first, second, and third warp yarns is 90:89:1; the ratio of the number of the first and second weft yarns is 1:1.

[0053] Dyeing and finishing include the following steps:

[0054] Pretreatment (alkali reduction): After desizing and scouring the greige fabric, alkali reduction treatment is carried out (the initial concentration of sodium hydroxide is 5g / L, the bath ratio is controlled at 1:12, the temperature is increased to 130℃ at 1.5℃ / min, and the treatment time is 35min; according to actual measurement, the overall alkali reduction rate of the fabric is about 26%). After treatment, the fabric is thoroughly washed with water until neutral.

[0055] Dyeing: A high-temperature, high-pressure dyeing machine is used, with 1.5% (owf) of environmentally friendly disperse dye (model: deep three primary colors) and matching auxiliaries added. The temperature is increased to 130℃ at a rate of 1.5℃ / min and held for 45 minutes. After dyeing, the temperature is slowly lowered.

[0056] Post-treatment: Perform reduction cleaning (80℃, 15min), then hot water wash, cold water wash, and finally set at 170℃ for 45 seconds to obtain the dyed and finished fabric.

[0057] The post-processing includes the following steps:

[0058] (1) The dyed and finished fabric is immersed in a pretreatment solution (which is a diluted working solution, wherein the concentration of nano zinc oxide is 3g / L, and the pretreatment solution is prepared by diluting a concentrated solution containing the following weight percentage components: 30% nano zinc oxide, 5% polymeric dispersant, 2% sodium citrate, 3% silane coupling agent, and the remainder is solvent, and the pH is adjusted to 6 with dilute acetic acid; the silane coupling agent is KH550, and the solvent is deionized water and ethanol mixed in a volume ratio of 9:1; the preparation method of the concentrated solution and the polymeric dispersant are the same as in Example 1), the treatment temperature is controlled at 70℃, and after treatment for 30min, it is pre-dried at 100℃ for 3min to make the fabric initially dry, and then baked at 150℃ for 2min to obtain the pretreated fabric for use;

[0059] (2) Take the pretreated fabric from step (1) and add the foaming slurry (which includes the following components by weight percentage: 65% aqueous polyurethane dispersion (50% solid content), 15% polycarbonate polyol dispersion (50% solid content), 8% calcium carbonate (particle size ≤ 2μm), 2% external crosslinking agent, 2% foam stabilizer, 1% wetting and dispersing agent, 1.5% thickener, and the remainder is water; wherein the aqueous polyurethane dispersion is an aqueous dispersion of aliphatic polyurethane, which does not contain free isocyanate groups, specifically Covestro Bayhydrol). ®UH2888; the specific model of the polycarbonate polyol dispersion is PU623A; the external crosslinking agent is polycarbodiimide with a solid content of 40%, such as Shanghai Youen Chemical UN-557; the foam stabilizer is L-580; the wetting and dispersing agent is DISPERBYK-2015; the thickener is ASE type) are added into a mechanical foaming machine, and air is mixed in through high-speed shearing. The stirring speed is adjusted to 1200 rpm, and the foaming ratio is controlled to 1:3.5 to obtain a foaming slurry with a micron-sized bubble diameter of 150-200 μm. This slurry is then coated onto the surface of the fabric, and the wet film coating thickness is controlled to be 0.26 mm. The fabric is first pre-cured at 85℃ for 2 min, and then post-cured at 150℃ for 5 min. Finally, a dielectric barrier discharge (DBD) plasma device is used with nitrogen (gas flow rate controlled at 10 L / min) as the working gas for 45 s (power of 60 W) to obtain a surface-activated porous structure fabric.

[0060] (3) Within 15 minutes after the plasma treatment is completed, take the porous structure fabric activated in step (2), and dilute the coating concentrate (which includes the following components by weight percentage: 65% silicone acrylic resin, 20% polyethyl acrylate, 2% methacryloyloxypropyltrimethoxysilane, 3% isocyanate crosslinking agent, 0.5% wetting and leveling agent, 0.3% defoamer, and the remainder is water; the wetting and leveling agent is BYK-346, and the defoamer is BYK-028; the isocyanate crosslinking agent is packaged separately from the other components and mixed when used) with deionized water, adjust the solid content of the working liquid to 18%, stir evenly, let it stand to defoam, and then use an ultrasonic nozzle to perform multi-layer spraying (spraying pressure controlled at 0.3MPa, spraying distance at 25cm, and setting the single wet film spraying amount to 4g / m). 2 After spraying once, the coating is dried in the oven at 90℃ for 45 seconds. This process is repeated 6 times to control the coating thickness to 4μm. After spraying, the coating is pre-baked at 100℃ for 2 minutes to allow it to level and react initially. Then, it is baked at 155℃ for 3 minutes to obtain a highly breathable food-grade fabric.

[0061] To verify that the food-grade clothing fabric of the present invention has good comfort, durability, and protection, the following comparative examples were set up with reference to Example 2. Specific performance test methods and standards are as follows: Comfort: weight (GB / T4669), breathability (GB / T5453), moisture permeability (GB / T12704.1-2009). Durability: washability was tested according to GB / T8629-2017, measuring the performance retention rate after different washing cycles. Protection: Antistatic properties: surface resistivity (GB / T 12703.4-2010). Antibacterial properties: antibacterial rate (GB / T 20944.3-2008). Water repellency (surface moisture resistance): tested according to GB / T 4745-2012 "Test and Evaluation of Water Repellency of Textiles - Water Repellency Method", with results expressed as "water repellency rating", divided into 5 levels (level 1 is the worst, level 5 is the best). Detailed test data are shown in Tables 1 and 2.

[0062] Comparative Example 1

[0063] Unlike Example 2, the yarn preparation is as follows: the 75D alkali-soluble yarn in the second and third warp yarns is ordinary 75D DTY filament, and the rest of the operation is the same.

[0064] Comparative Example 2

[0065] Unlike Example 2, step (2) is missing in the post-processing, but the rest of the operations are the same.

[0066] Comparative Example 3

[0067] Unlike Example 2, step (3) is missing in the post-processing, but the rest of the operations are the same.

[0068] Comparative Example 4

[0069] Unlike Example 2, the plasma treatment is missing in step (2) of the post-processing, but the rest of the operations are the same.

[0070] Comparative Example 5

[0071] Unlike Example 2, the foaming slurry in step (2) of the post-processing is a commercially available ordinary polyurethane foam coating slurry, and the rest of the operation is the same.

[0072]

[0073] The data in Table 1 shows that the food fabric prepared by the method of Example 2 of the present invention is superior to other examples and comparative examples in terms of air permeability, moisture permeability, antibacterial rate and water repellency.

[0074]

[0075] As can be seen from Table 2, the food clothing fabric prepared using the process method of Example 2 of the present invention has good durability.

[0076] As can be seen from the above, this invention utilizes a triple structure—alkali-soluble fibers forming micropores, a composite foaming coating constructing stable air-permeable channels, and an ultra-thin functional coating for protection—to achieve not only excellent initial air permeability, moisture permeability, and protective performance (see Table 1), but more importantly, to effectively maintain these high performances after multiple washes (see Table 2), solving the problem of balancing high performance and durability in traditional technologies. In contrast, Comparative Example 1 suffers from insufficient air permeability due to the lack of alkali-soluble fibers; Comparative Examples 2 and 3, respectively, lack a foaming layer or coating, resulting in an inability to balance protection and washability; while Comparative Examples 4 and 5 demonstrate the crucial role of plasma treatment and specialized foaming slurry in improving interlayer bonding strength and the stability of air-permeable channels.

[0077] In summary, the air permeability of the high-breathability food garment fabric described in this invention reaches 500-600 mm / s (tested according to GB / T5453, 100Pa pressure difference), significantly higher than similar functional fabrics. This breathability is achieved through a multi-layered, three-dimensional air-permeable channel design: firstly, the alkali-soluble fibers in the inner yarn are dissolved by alkali reduction, forming permanent micropores within the yarn; secondly, the foamed coating forms a 50-200μm interconnected porous network after mechanical foaming and gradient drying; finally, the ultra-thin functional coating thickness is controlled below 5μm, resulting in extremely low resistance to gas diffusion. The synergistic effect of these three elements enables the fabric to maintain extremely high air and moisture permeability while possessing excellent water-repellent, antibacterial, and antistatic properties.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a highly breathable food garment fabric, characterized in that, This includes yarn preparation, weaving, dyeing and finishing, and post-processing. The yarn preparation is as follows: the first warp yarn is a twisted 150D DTY filament single yarn; the second warp yarn is a composite yarn made by twisting 75D DTY filament and 75D alkali-soluble yarn together; the third warp yarn is a multifunctional composite yarn made by twisting 75D DTY filament, 75D alkali-soluble yarn and 20D conductive yarn together; the first weft yarn is a twisted 150D DTY filament single yarn, and the second weft yarn is a composite yarn made by twisting 75D DTY filament and 75D alkali-soluble yarn together; the twist of the first, second, and third warp yarns and the first and second weft yarns is 500-1000 twists / m. The post-processing includes the following steps: (1) Immerse the dyed and finished fabric in the pretreatment solution, control the treatment temperature and treatment time, and then dry and bake to obtain the pretreated fabric for use. (2) Take the pre-treated fabric described in step (1), apply the foaming slurry to the surface of the fabric after mechanical foaming, and control the coating thickness; first, pre-curing treatment is carried out at a temperature not exceeding 85°C, then post-curing treatment is carried out at a temperature not exceeding 150°C, and finally plasma treatment is carried out to obtain a surface-activated porous structure fabric. (3) Within 30 minutes after the plasma treatment is completed, take the porous structure fabric activated in step (2), dilute the coating concentrate and spray it onto the fabric multiple times, control the coating thickness and drying temperature, and bake it after spraying to obtain a highly breathable food clothing fabric.

2. The method for preparing a highly breathable food garment fabric according to claim 1, characterized in that, The pretreatment solution in step (1) is a diluted working solution, wherein the concentration of nano zinc oxide is 1-3 g / L; the pretreatment solution is prepared by diluting a concentrated solution containing the following components by weight percentage: 10-30% nano zinc oxide, 1-5% polymeric dispersant, 0.5-2% sodium citrate, 1-3% silane coupling agent, and the remainder is solvent; the treatment temperature is 50-70℃, and the treatment time is 10-30 min.

3. The method for preparing a highly breathable food garment fabric according to claim 1, characterized in that, The foaming slurry in step (2) comprises the following components by weight percentage: 55-65% aqueous polyurethane dispersion (solid content 40-50%), 10-15% polycarbonate polyol dispersion (solid content 40-50%), 5-8% calcium carbonate, 0.5-2% external crosslinking agent, 0.5-2% foam stabilizer, 0.2-0.5% wetting and dispersing agent, 0.5-1.5% thickener, and the remainder is water; the foaming slurry is mechanically stirred to form foam with bubbles of 50-200μm in diameter, and then coated on the surface of the fabric.

4. The method for preparing a highly breathable food garment fabric according to claim 1, characterized in that, In step (2), the wet film coating thickness is controlled to be 0.13-0.26 mm; the temperature of the pre-curing treatment is 75-85℃ and the time of the pre-curing treatment is 1-2 min; the temperature of the post-curing treatment is 120-150℃ and the time of the post-curing treatment is 3-5 min; the power of the plasma treatment is 50-60 W and the treatment time is 30-45 s.

5. The method for preparing a highly breathable food garment fabric according to claim 1, characterized in that, The coating concentrate in step (3) comprises the following components by weight percentage: 50-65% silicone acrylic resin, 10-20% ethyl polyacrylate, 0.8-2% methacryloyloxypropyltrimethoxysilane, 1-3% isocyanate crosslinking agent, 0.2-0.5% wetting and leveling agent, 0.1-0.3% defoamer, and the balance being water.

6. The method for preparing a highly breathable food garment fabric according to claim 1, characterized in that, The coating thickness in step (3) is less than 5 μm, and the drying temperature is 150-160℃.

7. The method for preparing a highly breathable food garment fabric according to claim 1, characterized in that, The weaving process employs a double-warp, double-layer structure. The first warp yarn is the outer warp, which interweaves with the first weft yarn to form the outer layer. The second and third warp yarns are the inner warp, which together interweave with the second weft yarn to form the inner layer. The ratio of the number of the first, second, and third warp yarns is 90:89:1, and the ratio of the number of the first and second weft yarns is 1:

1.

8. The method for preparing a highly breathable food garment fabric according to claim 1, characterized in that, The dyeing and finishing process includes pretreatment, dyeing, and posttreatment. In the pretreatment, when reducing the amount of alkali, the initial concentration of sodium hydroxide is 3-5 g / L, the bath ratio is controlled at 1:8-12, the temperature is increased to 120-130℃ at a rate of 0.5-1.5℃ / min, and the treatment time is 25-35 min.

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