Antibacterial fabric, preparation method and application

Abstract

The invention relates to the technical field of alginic acid and derivatives thereof, and particularly discloses an antibacterial fabric, a preparation method and application. The anti-bacterial fabric comprises a one-way moisture guiding layer and an anti-bacterial layer, the functional core layer is a honeycomb-shaped porous fiber net and comprises a compound formed by alginic acid and derivatives thereof and organosilane quaternary ammonium salt which are connected through an alkylation reaction, and waterborne polyurethane; porous starch microspheres loaded with an auxiliary antibacterial agent are packaged in pores of the functional core layer. The preparation method comprises the steps of preparation of porous starch microspheres, preparation of a spinning solution, electrostatic spinning, curing, hot-pressing compounding and the like. According to the antibacterial fabric disclosed by the invention, through synergism of the alkylated compound, microsphere slow release and a porous structure, the antibacterial ability is greater than or equal to 97% after 50 times of water washing; oWTC is larger than or equal to 0.9, skin irritation is 0 point, the problems that a traditional fabric is short in antibacterial time, poor in moisture conductivity and prone to skin irritation are solved, and the fabric can be used for sportswear, underwear and the like.

Description

Technical Field

[0001] This invention relates to the field of alginate and its derivatives, and more specifically to an antibacterial fabric, its preparation method, and its application. Background Technology

[0002] With increasing consumer awareness of health, antibacterial fabrics are being used more and more widely in the apparel industry. Traditional antibacterial fabrics often use a single antibacterial agent coating or fiber blending, which has problems such as short-lasting antibacterial effect, poor breathability, and easy skin irritation. At the same time, sportswear, underwear, and other close-fitting garments have high requirements for moisture-wicking performance, and existing antibacterial fabrics often struggle to achieve a synergistic optimization of antibacterial and moisture-wicking functions.

[0003] Sodium alginate, a natural polysaccharide, is biocompatible and environmentally friendly, but its antibacterial activity is relatively weak. Organosilicon quaternary ammonium salt antibacterial agents have a broad antibacterial spectrum, but their binding force with fiber substrates is insufficient, leading to easy loss. Furthermore, issues such as the controlled release of antibacterial agents and the stability of interlayer composites in fabrics have not yet been effectively resolved. Therefore, developing a composite fabric that is durable, highly moisture-wicking, comfortable, and safe has significant practical application value. Summary of the Invention

[0004] The purpose of this invention is to provide an antibacterial fabric, its preparation method, and its application to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, in one respect, the present invention provides an antibacterial fabric, comprising: One-way moisture-wicking layer, made of hydrophilic fibers; The functional core layer is a honeycomb porous fiber network containing a complex of alginic acid and its derivatives linked by an alkylation reaction with organosilicon quaternary ammonium salts, as well as waterborne polyurethane. The functional core layer contains porous starch microspheres loaded with an auxiliary antibacterial agent encapsulated within its pores.

[0006] Preferably, the alginate and its derivatives are sodium alginate, and the organosilicon quaternary ammonium salt is dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride.

[0007] Preferably, the auxiliary antibacterial agent is a natural plant essential oil, including at least one of citronellol and eucalyptol.

[0008] Preferably, the honeycomb porous fiber web is prepared by electrospinning technology, and the pore size of a single honeycomb unit is 10-100μm, with a porosity greater than 80%.

[0009] Preferably, the porous starch microspheres have a particle size of 5-20 μm.

[0010] Preferably, by weight, the functional core layer comprises: 50-70 parts of alginic acid derivative, 20-40 parts of waterborne polyurethane, 5-15 parts of organosilicon quaternary ammonium salt, and 5-15 parts of porous starch microspheres loaded with auxiliary antibacterial agents.

[0011] On the other hand, the present invention also provides a method for preparing the above-mentioned antibacterial fabric, comprising the following steps: Preparation of porous starch microspheres loaded with auxiliary antibacterial agents; The alginate derivative solution was mixed with organosilicon quaternary ammonium salt, heated and stirred, and then cooled before being mixed with aqueous polyurethane and porous starch microspheres to prepare a spinning solution. The functional core layer is spun from the spinning solution by electrospinning. The functional core layer is cured at 100-120℃ for 20-40 minutes; The cured functional core layer is bonded to the unidirectional moisture-wicking layer by a hot-pressing process.

[0012] Preferably, the electrospinning process parameters are: voltage 15-25kV, receiving distance 15-20cm, and ambient humidity controlled at 40%-60%.

[0013] Preferably, the process parameters for hot-pressing composite are: temperature 110-130℃, pressure 0.3-0.6MPa, and time 20-40s.

[0014] Furthermore, the present invention also discloses the application of the above-mentioned antibacterial fabric in the preparation of sportswear, casual wear, underwear or socks.

[0015] The beneficial effects of this invention are as follows: This invention utilizes hydrophilic fibers to rapidly absorb sweat from the skin and transfer it to the functional core layer. In the functional core layer, the hydroxyl groups of sodium alginate and the silanol groups formed by the hydrolysis of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride undergo alkylation to form a stable complex, resulting in a condensation reaction and a robust Si-OC covalent bond. This permanently anchors the antibacterial components within the fiber network, significantly enhancing the durability of the function. The quaternary ammonium groups of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride disrupt bacterial cell membranes, while the polysaccharide structure of sodium alginate enhances the binding force between the antibacterial agent and the fiber. Porous starch microspheres encapsulate natural plant essential oils as auxiliary antibacterial agents, extending the antibacterial effect through the slow-release effect of the honeycomb pores. The high-porosity honeycomb structure prepared by electrospinning ensures air permeability and provides a stable encapsulation environment for the microspheres. The hot-pressing composite process ensures strong interlayer bonding. Detailed Implementation

[0016] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0017] It should be noted that all reagents and raw materials used in this invention are commercially available, and the reagents are of analytical grade.

[0018] The waterborne polyurethane is from UBE Corporation of Japan, model number UW-1005D-C1.

[0019] Sodium alginate is sourced from Qingdao Mingyue Algae Group Co., Ltd., with the model number MWF and a viscosity of 600-800 cps.

[0020] The polyester fiber is sourced from Sinopec Yizheng Chemical Fiber Co., Ltd., and its model number is FCLS-75.

[0021] The viscose fiber is sourced from Lenzing and is designated EcoVero®.

[0022] Example 1 Functional core layer components (parts by weight): 50 parts sodium alginate, 30 parts waterborne polyurethane, 10 parts dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, and 10 parts porous starch microspheres loaded with citronellol (average particle size of microspheres 5 μm).

[0023] Preparation steps: S1: Preparation of porous starch microspheres: S11: Take a starch aqueous dispersion with a mass concentration of 25%, add citronellal and starch to the starch solution at a mass ratio of 1:5, and shear at 8000 r / min for 10 min using a high-speed shear emulsifier to make citronellal uniformly dispersed in the starch aqueous dispersion to form a premixed aqueous phase. S12: Add soybean oil as the oil phase solvent to a three-necked flask. Add Span60 emulsifier and oil phase solvent to the three-necked flask at a mass-volume ratio of 1:100. Stir at 30°C for 15 minutes (500 r / min) to completely dissolve Span60 and obtain the oil phase. S13: Slowly drop the premixed aqueous phase into the oil phase (dropping rate 2 mL / min, volume ratio of oil phase to aqueous phase 5:1). After the addition is complete, shear the mixture for 20 min at 10000 r / min using a high-speed shear emulsifier to form a W / O emulsion. S14: Add sodium hydroxide solution dropwise to the W / O emulsion to adjust the pH to 9, heat to 45℃, slowly add the crosslinking agent epichlorohydrin (starch to epichlorohydrin mass-volume ratio of 50:1, g / mL), and stir the reaction at 600 r / min for 5 h. S15: After the reaction is complete, cool to room temperature, add 1.2 times the volume of the W / O emulsion of anhydrous ethanol to break the emulsion, let stand for 30 min to allow the microspheres to settle, and collect the microsphere precipitate by centrifugation (3000 r / min, 10 min). Wash three times with anhydrous ethanol (soaking for 10 min each time, starch to anhydrous ethanol mass-volume ratio of 1:3, g / mL) to remove residual oil phase and emulsifier, and obtain wet microspheres; S16: Wash the wet microspheres with deionized water until neutral, place the neutral wet microspheres in a vacuum freeze dryer, and dry them for 24 hours at -50℃ and 10Pa vacuum to obtain white, loose porous starch microspheres loaded with citronellol.

[0024] S2: Preparation of spinning solution: Sodium alginate was dissolved in an aqueous ethanol solution (water / ethanol volume ratio of 8:2), and dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride was added. The temperature was raised to 55°C and stirred at 300 r / min for 6 h. At this time, the aim was to fully hydrolyze the methoxysilyl group of the organosilicon quaternary ammonium salt to generate highly reactive silanol groups, which then underwent preliminary physical mixing and hydrogen bonding with sodium alginate molecules. After cooling to room temperature, waterborne polyurethane and porous starch microspheres loaded with citronellol were added, and stirring was continued until completely dissolved to prepare a spinning solution with a solid content of 10%. S3: Electrospinning: Using electrospinning technology, the spinning solution is spun into a functional core layer. Electrospinning parameters: voltage 15kV, receiving distance 15cm, ambient humidity 40%, to spin a honeycomb porous fiber web (average pore size 10μm, porosity 85%). In this process, the solvent evaporates rapidly, which greatly promotes the condensation reaction between silanol groups and sodium alginate alcohol hydroxyl groups, and begins to form covalent bonds in the fiber interior and on the surface. S4: Curing: The functional core material obtained by electrospinning is placed in a forced-air drying oven and cured at 110°C for 30 minutes; this step is crucial to ensure the formation of stable Si-OC covalent bonds. Heat treatment provides the final energy to drive the dehydration condensation reaction to complete, thereby permanently anchoring the antibacterial components in the fiber network and greatly improving the durability of the function; S5: Hot-press lamination: The cured functional core layer is laminated with cotton fibers through a hot-press process to obtain antibacterial fabric. Hot-press lamination process: temperature 110℃, pressure 0.3MPa, time 20s.

[0025] Example 2 Functional core layer components (parts by weight): 60 parts sodium alginate, 20 parts waterborne polyurethane, 15 parts dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, and 5 parts porous starch microspheres loaded with eucalyptol (average particle size of microspheres 12 μm).

[0026] Preparation steps: S1: Preparation of porous starch microspheres: The preparation steps are the same as in Example 1, except that: The mass concentration of the starch aqueous dispersion was 18%, the mass ratio of eucalyptol to starch was 1:8, the oil-water volume ratio was 10:1, and the oil-water mixing shear rate was 8000 r / min. S2: Preparation of spinning solution: Sodium alginate was dissolved in an aqueous ethanol solution (water / ethanol volume ratio of 8:2), dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride was added, the temperature was raised to 50℃, and the reaction was maintained at a stirring rate of 400r / min for 8h. After cooling to room temperature, waterborne polyurethane and porous starch microspheres loaded with citronellol were added, and stirring was continued until completely dissolved to prepare a spinning solution with a solid content of 12%. S3: Electrospinning: Using electrospinning technology, the spinning solution is spun into a functional core layer. Electrospinning parameters: voltage 20kV, receiving distance 18cm, ambient humidity 50%, to spin a honeycomb porous fiber web (average pore size 50μm, porosity 88%). S4: Curing: Place the functional core material obtained by electrospinning in a forced-air drying oven and cure at 100℃ for 40 min; S5: Hot-press lamination: The cured functional core layer is laminated with viscose fiber through a hot-press process to obtain an antibacterial fabric. Hot-press lamination process: temperature 120℃, pressure 0.45MPa, time 30s.

[0027] Example 3 Functional core layer components (parts by weight): 70 parts sodium alginate, 40 parts waterborne polyurethane, 5 parts dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, and 15 parts porous starch microspheres loaded with citronellal and eucalyptol (mass ratio 1:1) (average particle size of microspheres 20 μm).

[0028] Preparation steps: S1: Preparation of porous starch microspheres: The preparation steps are the same as in Example 1, except that: The mass concentration of the starch aqueous dispersion was 11%, the mass ratio of (citronellol + eucalyptol) to starch was 1:6, the oil-water volume ratio was 20:1, and the oil-water mixing shear rate was 5000 r / min. S2: Preparation of spinning solution: Sodium alginate was dissolved in an aqueous ethanol solution (water / ethanol volume ratio of 8:2), dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride was added, the temperature was raised to 60℃, and the reaction was maintained at a stirring rate of 500r / min for 5h. After cooling to room temperature, waterborne polyurethane and porous starch microspheres loaded with citronellol were added, and stirring was continued until completely dissolved to prepare a spinning solution with a solid content of 8%. S3: Electrospinning: Using electrospinning technology, the spinning solution is spun into a functional core layer. Electrospinning parameters: voltage 25kV, receiving distance 20cm, ambient humidity 60%, to spin a honeycomb porous fiber web (average pore size 100μm, porosity 90%). S4: Curing: Place the functional core material obtained by electrospinning in a forced-air drying oven and cure at 120℃ for 20 min; S5: Hot-press lamination: The cured functional core layer is laminated with polyester fiber through a hot-press process to obtain antibacterial fabric. Hot-press lamination process: temperature 130℃, pressure 0.6MPa, time 40s.

[0029] Example 4 Functional core layer components (parts by weight): 55 parts sodium alginate, 35 parts aqueous polyurethane, 12 parts dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, and 8 parts porous starch microspheres loaded with citronellol (average particle size of microspheres 15 μm).

[0030] Preparation steps: S1: Preparation of porous starch microspheres: The preparation steps are the same as in Example 1, except that: The mass concentration of the starch aqueous dispersion was 20%, the mass ratio of citronellal to starch was 1:7, the oil-water volume ratio was 15:1, and the oil-water mixing shear rate was 7000 r / min. S2: Preparation of spinning solution: Sodium alginate was dissolved in an aqueous ethanol solution (water / ethanol volume ratio of 8:2), dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride was added, the temperature was raised to 53℃, and the reaction was maintained at a stirring rate of 350r / min for 10h. After cooling to room temperature, waterborne polyurethane and porous starch microspheres loaded with citronellol were added, and stirring was continued until completely dissolved to prepare a spinning solution with a solid content of 11%. S3: Electrospinning: The spinning solution is spun into a functional core layer through electrospinning. Electrospinning parameters: voltage 18kV, receiving distance 17cm, ambient humidity 45%, to produce a honeycomb porous fiber web (average pore size 60μm, porosity 86%). S4: Curing: Place the functional core material obtained by electrospinning in a forced-air drying oven and cure at 115℃ for 25 min; S5: Hot-press lamination: The cured functional core layer is laminated with cotton fibers through a hot-press process to obtain antibacterial fabric. Hot-press lamination process: temperature 115℃, pressure 0.5MPa, time 25s.

[0031] Comparative Example 1 The functional core layer composition is the same as in Example 2; Preparation method: Step S4 is omitted, the rest is the same as in Example 2.

[0032] Comparative Example 2 Functional core layer components: "Ordinary starch granules" are used instead of "porous starch microspheres", and the rest is the same as in Example 2; Preparation method: In step S1, citronellal and ordinary starch are mixed by direct mixing method, and the rest is the same as in Example 2.

[0033] Comparative Example 3 Functional core layer composition: Same as in Example 2; Preparation method: In step S3, the electrospinning parameters are adjusted to "voltage 10kV, receiving distance 10cm" to prepare a dense fiber web, and the rest is the same as in Example 2.

[0034] Comparative Example 4 The functional core layer component is the same as in Example 2, except that dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride is replaced with dimethyloctadecylammonium chloride. Preparation method: Same as in Example 2.

[0035] The antibacterial fabrics obtained in Examples 1-4 and Comparative Examples 1-4 were subjected to performance tests. The test standards and methods are as follows, and the test results are recorded in Table 1.

[0036] Antibacterial durability: The sample was washed 50 times according to the A101 procedure specified in GB / T 3921-2008 (simulating household washing, water temperature 40℃±3℃, detergent dosage 5g / L, and dehydration after every 5 washes). After washing, Escherichia coli (ATCC25922) and Staphylococcus aureus (ATCC6538) were selected as test bacteria. The treated sample and bacterial solution were shaken and contacted for 24 hours at a constant temperature of 37℃±1℃ using the "shaking flask method". Subsequently, the number of viable bacteria in the bacterial solution before and after contact was determined by plate count method. The antibacterial rate was calculated according to the formula "antibacterial rate = (1 - number of viable bacteria after contact / number of viable bacteria before contact) × 100%" to reflect the antibacterial durability of the fabric after multiple washes.

[0037] Moisture wicking performance: Tested according to GB / T 21655.2-2008 standard OWTC (One-Way) The Transport Capacity (OWTC) index, also known as the one-way transfer index, is used to quantify the one-way moisture wicking capacity of fabrics. The test method is as follows: Cut a 200mm×200mm sample and equilibrate it for 24 hours in a standard atmospheric environment (temperature 20℃±2℃, relative humidity 65%±4%). Using a YG(B)819D moisture absorption and quick-drying tester, place an 80mm diameter circular filter paper on top of the sample, and add 0.2mL of deionized water (water temperature 20℃±2℃) to the center of the filter paper. At 10s, 30s, 60s, 120s, and 180s after the water drop, measure the area of ​​water migration on the reverse side (non-drip side) and the area of ​​water residue on the front side (drip side) of the sample. Calculate the one-way transfer index at each time point according to the standard formula, and take the value at 180s as the final OWTC index. The higher the index (maximum 1.0), the better the one-way moisture wicking performance of the fabric.

[0038] Skin irritation: Tests were conducted according to GB / T 21604-2008. Ten healthy volunteers (aged 20-40 years, with no history of skin allergies) were selected. Four 25mm×25mm test areas (interval ≥20mm) were selected on both sides of the spine on the back of each volunteer. A 20mm×20mm sample (sterilized after cutting) was applied to the test area and fixed with medical tape to form a closed environment. The sample was removed after 24 hours. Skin reactions in the test area were observed at 0.5h, 24h, and 48h after removal. According to the standard grading: no reaction was 0 points, mild erythema (indistinct borders) was 1 point, moderate erythema (clear borders) was 2 points, severe erythema (with edema) was 3 points, and erythema + edema + blisters was 4 points. The average of the highest scores of the 10 volunteers at each time point was taken as the final irritation score, with 0 points indicating no irritation and ≥1 points indicating varying degrees of irritation.

[0039] As shown in Example 2 and Comparative Example 1, omitting step S4 reduces the antibacterial rate from 98.1% to 68.3% after 50 washes, and causes slight irritation. This is because omitting step S4 prevents the formation of a stable Si-OC covalent bond, and the antibacterial agent (dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride) cannot be anchored to the sodium alginate molecular chain. It is only physically dispersed in the spinning solution and ultimately exists in the functional core fiber in a "free state" or "weakly adsorbed state." The antibacterial agent is easily lost and can easily lead to increased skin irritation. This demonstrates that the "alkylation reaction" in Example 2 not only solves the problem of antibacterial agent loss but also reduces the risk of antibacterial agent release through covalent bonding.

[0040] As can be seen from Example 2 and Comparative Example 2, the antibacterial rate of ordinary starch granules is only 75.6%, which is much lower than the 98.1% of porous microspheres. The reason is that the "porous starch microspheres" in Example 2 are constructed with a three-dimensional porous structure by reverse emulsification. This three-dimensional porous structure can achieve slow release of antibacterial agents, avoid skin irritation caused by excessively high initial concentrations, and prolong the antibacterial effect. Ordinary starch granules do not have a porous structure and therefore cannot achieve slow release of antibacterial agents.

[0041] As can be seen from Example 2 and Comparative Example 3, the OWTC index of the dense fiber web dropped sharply from 0.90 to 0.52. The reason is that the honeycomb porous structure is the core of rapid moisture transfer. By constructing "capillary channels" with an average pore size of 50μm, the technical problem of poor moisture conduction of the dense structure is overcome. Comparative Example 2 destroyed the porous structure by adjusting the parameters, which verified the irreplaceable role of the high porosity honeycomb structure in moisture conduction performance.

[0042] As can be seen from Example 2 and Comparative Example 4, dimethyl octadecyl ammonium chloride and sodium alginate are only combined through weak electrostatic interaction without covalent cross-linking. During the spinning process, the fiber molecular chains are easy to slide, forming an irregular and loose structure. In some areas, the fibers are too densely packed, blocking the moisture transfer channels, which leads to a sharp drop in the antibacterial rate and OWTC index. This proves that the lack of silanization bonding not only affects the antibacterial properties, but also destroys the moisture-conducting basis of the porous structure of the fiber.

[0043] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention. Furthermore, it should be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations.

[0044] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. An antibacterial fabric, characterized in that, include: One-way moisture-wicking layer, made of hydrophilic fibers; The functional core layer is a honeycomb porous fiber network containing a complex of alginic acid and its derivatives linked by an alkylation reaction with organosilicon quaternary ammonium salts, as well as waterborne polyurethane. The functional core layer contains porous starch microspheres loaded with an auxiliary antibacterial agent encapsulated within its pores.

2. The antibacterial fabric according to claim 1, characterized in that, The alginic acid and its derivatives are sodium alginate, and the organosilicon quaternary ammonium salt is dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride.

3. The antibacterial fabric according to claim 1, characterized in that, The auxiliary antibacterial agent is a natural plant essential oil, including at least one of citronellol and eucalyptol.

4. The antibacterial fabric according to claim 1, characterized in that, The honeycomb porous fiber mesh is prepared by electrospinning technology, and the pore size of a single honeycomb unit is 10-100μm, with a porosity greater than 80%.

5. The antibacterial fabric according to claim 1, characterized in that, The porous starch microspheres have a particle size of 5-20 μm.

6. The antibacterial fabric according to claim 1, characterized in that, By weight, the functional core layer comprises: 50-70 parts of alginic acid derivative, 20-40 parts of waterborne polyurethane, 5-15 parts of organosilicon quaternary ammonium salt, and 5-15 parts of porous starch microspheres loaded with auxiliary antibacterial agents.

7. A method for preparing an antibacterial fabric according to any one of claims 1-6, characterized in that, Includes the following steps: Preparation of porous starch microspheres loaded with auxiliary antibacterial agents; The alginate derivative solution was mixed with organosilicon quaternary ammonium salt, heated and stirred, and then cooled before being mixed with aqueous polyurethane and porous starch microspheres to prepare a spinning solution. The functional core layer is spun from the spinning solution by electrospinning. The functional core layer is cured at 100-120℃ for 20-40 minutes; The cured functional core layer is bonded to the unidirectional moisture-wicking layer by a hot-pressing process.

8. The method for preparing the antibacterial fabric according to claim 7, characterized in that, The electrospinning process parameters are: voltage 15-25kV, receiving distance 15-20cm, and ambient humidity controlled at 40%-60%.

9. The method for preparing the antibacterial fabric according to claim 7, characterized in that, The parameters for the hot pressing process are: temperature 110-130℃, pressure 0.3-0.6MPa, and time 20-40s.

10. The use of the antibacterial fabric according to any one of claims 1-6 in the preparation of sportswear, casual wear, underwear or socks.

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