A method for manufacturing comfortable antibacterial protective clothing fabric and the prepared fabric

Abstract

The present invention provides a method for manufacturing a comfortable antibacterial protective clothing fabric and the prepared fabric. The finished comfortable antibacterial protective clothing fabric is obtained by blending polylactic acid elastic fiber and high-cooling high-strength high-modulus polyethylene fiber, and then subjecting to electron beam irradiation grafting modification. PLA raw materials with different characteristic viscosities are used to blend polylactic acid elastic fiber after two-component melt spinning and stretching, and high-cooling high-strength high-modulus polyethylene fiber, and then the fabric is prepared by electron beam irradiation grafting modification with cationic functional groups. The method solves the problem that functionality (such as antibacterial property, wear resistance, etc.) and wearing comfort are difficult to achieve at the same time in the existing protective clothing fabric production process. And the comfortable antibacterial protective clothing fabric prepared by the present invention has both long-lasting antibacterial property and soft hand feel, and has high wear resistance and cool contact feeling. The electron beam irradiation grafting modification technology solves the problem that the conventional antibacterial effect is poor after washing and the conventional irradiation grafting needs to introduce initiators and other potentially toxic substances.

Description

Technical Field

[0001] The invention belongs to the field of protective clothing fabrics, and particularly relates to a method for manufacturing comfortable antibacterial protective clothing fabrics and the prepared fabrics. Background Art

[0002] Protective clothing refers to work clothing designed to protect the human body from physical, chemical, and biological hazards. Besides meeting high strength and abrasion resistance requirements, protective clothing often varies depending on its purpose and principle. Types include firefighting suits, industrial protective clothing, medical protective clothing, military protective clothing, and protective clothing for special populations. With the recurrence of the epidemic in recent years, medical staff have increasingly demanded more protective clothing, placing higher demands on antimicrobial properties, wear resistance, and comfort.

[0003] Conventional approaches to improving antimicrobial properties include incorporating metal ions into fabrics and applying post-treatment surface coatings. Simply adding metal ions can easily leach out, resulting in a less durable antimicrobial effect. Post-treatment surface coatings also compromise the fabric's comfort.

[0004] Chinese patent CN115214204A discloses an antibacterial medical protective clothing fabric and its preparation method, which uses an antibacterial coating process to obtain antibacterial protective clothing. In order to ensure the durability of antibacterial properties, this method adds a waterproof and oil-proof coating, which is complex and affects wearing comfort.

[0005] Chinese patent CN216723211U discloses a breathable anti-infection protective clothing that uses a nano-silver ion coating + antibacterial fiber composite to improve the antibacterial effect. Although this method improves the overall antibacterial effect, it affects wearing comfort.

[0006] With the development of technology, in recent years, the functionality of fibers has been enhanced through irradiation grafting modification. Chinese patent CN103952908A discloses an antiviral and antibacterial fiber, its preparation method, and its use. This method uses monomers with cationic functional groups and utilizes ultraviolet light irradiation or gamma-ray irradiation technology to modify the fiber surface. Although the resulting product has good functionality, the modification process is complex and requires the addition of an initiator for irradiation.

[0007] Now with the popular trend of bio-based concepts, more and more attention is paid to polylactic acid fiber. Polylactic acid fiber is naturally weakly acidic and has a certain antibacterial effect. By enhancing the antibacterial properties of polylactic acid fiber, it can be used in the antibacterial textile industry.

[0008] Chinese patent CN1891870A discloses a method for producing antibacterial polylactic acid antibacterial fiber, in which antibacterial polylactic acid fiber is obtained by adding silver ion antibacterial masterbatch. This method has poor spinnability when manufacturing polylactic acid fiber, and the silver ions in the obtained antibacterial fiber are easily precipitated, the antibacterial property is not long-lasting, and the resulting textile is less comfortable.

[0009] Methods for improving the comfort of polylactic acid fibers often involve creating stretch yarns or parallel elastic fibers. Chinese patent CN109853084A discloses a polylactic acid / polyester elastomer composite elastic fiber and its preparation method. This fiber, formed from polylactic acid and polyester elastomer, enhances elasticity and comfort. To improve the compatibility of polylactic acid and polyester elastomer, a high proportion of compatibilizer is added during spinning, resulting in decreased spinnability and product performance. Summary of the Invention

[0010] The object of the present invention is to provide a method for manufacturing a comfortable antibacterial protective clothing fabric and the resulting fabric. The technical solution of the present invention is:

[0011] A method for manufacturing comfortable antibacterial protective clothing fabric is provided. The fabric is obtained by blending polylactic acid elastic fiber and high-strength and high-modulus polyethylene fiber, and then undergoing electron beam irradiation grafting modification. The method comprises the following steps:

[0012] (1) Preparation of polylactic acid elastic fiber;

[0013] (2) Blended fabric of antibacterial modified polylactic acid elastic fiber and high-strength and high-modulus polyethylene fiber with high coolness;

[0014] (3) The fabric is modified by electron beam irradiation grafting with cationic functional groups.

[0015] In the manufacturing method of the comfortable antibacterial protective clothing fabric, the polylactic acid elastic fiber is prepared by: using polylactic acid raw materials with different intrinsic viscosities, raw material 1 is polylactic acid with an intrinsic viscosity of 1.2~1.7 dl / g, and raw material 2 is polylactic acid with an intrinsic viscosity of 0.6~1.1 dl / g, spinning POY fiber through a two-component melt spinning machine, and obtaining antibacterial modified polylactic acid elastic fiber after low-temperature texturization.

[0016] In the manufacturing method of the comfortable antibacterial protective clothing fabric, the high-cooling high-strength high-modulus polyethylene fiber has a contact coolness Qmax of 0.4W / cm 2 Above; fiber breaking strength is above 10 cN / dtex, elastic modulus is above 400 cN / dtex, elongation at break is below 6%; fiber intrinsic viscosity is 1.5~10 dl.

[0017] In the method for manufacturing the comfortable antibacterial protective clothing fabric, the blending ratio of the antibacterial modified polylactic acid elastic fiber and the high-cooling high-strength and high-modulus polyethylene fiber is 3:7 to 7:3.

[0018] In the manufacturing method for comfortable antimicrobial protective clothing fabric, the electron beam irradiation grafting modification method with cationic functional groups is as follows: a blend of the antimicrobial modified polylactic acid elastic fiber and the high-cooling, high-strength, high-modulus polyethylene fiber is hydrophilically pretreated and then padded in a solution containing a cationic functional group monomer at a liquid volume of 20% to 100%. The padding operation is repeated 2 to 3 times, and the padded fabric is then electron beam irradiated at a dose of 30 to 80 kGy. After irradiation, the ungrafted monomer is removed with an organic solvent.

[0019] In the method for manufacturing the comfortable antibacterial protective clothing fabric, the hydrophilic pretreatment agent is a mixed solution of lipase and a nonionic surfactant. The monomer with a cationic functional group is preferably a vinyl cationic monomer.

[0020] The comfortable antibacterial protective clothing fabric is produced by the manufacturing method.

[0021] This invention addresses the difficulty in achieving both functionality (such as antimicrobial properties and abrasion resistance) and comfort in existing protective clothing fabric production processes. Furthermore, the comfortable antimicrobial protective clothing fabric produced using this invention combines long-lasting antimicrobial properties with a soft feel, high abrasion resistance, and a cool feel to the touch. The use of electron beam irradiation grafting modification technology addresses the issues of poor antimicrobial efficacy after conventional washing and the need for the introduction of potentially toxic substances such as initiators in conventional irradiation grafting. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a data chart of an embodiment of the present invention.

[0023] Figure 2 It is a data chart of the comparative example of the present invention. DETAILED DESCRIPTION

[0024] In the method for manufacturing comfortable antimicrobial protective clothing fabrics of the present invention, the polylactic acid elastic fiber is prepared by spinning polylactic acid raw materials of different intrinsic viscosities (raw material 1 is polylactic acid with an intrinsic viscosity of 1.2-1.7 dl / g, and raw material 2 is polylactic acid with an intrinsic viscosity of 0.6-1.1 dl / g) using a two-component melt spinning machine to produce POY fibers, which are then subjected to low-temperature texturization to obtain the polylactic acid elastic fiber. The use of polylactic acid fibers of different intrinsic viscosities ensures a sufficient difference in melt viscosity between the two components during melt spinning, thereby increasing the stress difference during spinning and enhancing the elasticity of the elastic fiber. When the intrinsic viscosity of raw material 1 is less than 1.2 dl / g, the difference in viscosity between the two components is too small, resulting in low fiber elasticity. When the intrinsic viscosity of raw material 1 is greater than 1.7 dl / g, the melt flowability is poor, resulting in poor spinnability and poor dispersion of the antimicrobial masterbatch. When the intrinsic viscosity of raw material 2 is less than 0.6 dl / g, the polylactic acid viscosity is too low, resulting in poor spinning and low fiber strength. When the intrinsic viscosity of raw material 2 is greater than 1.1 dl / g, the viscosity difference between the two components is too small, resulting in low fiber elasticity. By first preparing POY fiber and then stretching it at low temperatures, a highly elastic lactic acid elastic fiber can be obtained. Without stretching POY, using melt-spun FDY or a two-step stretching method, the fiber's elasticity is weak and unsatisfactory in terms of comfort and hand feel. When stretching at high temperatures, the stretch yarn of polylactic acid fiber is poorly formed, prone to stiffness, and has low elasticity. The preferred stretching temperature is 90°C to 120°C.

[0025] The high-cooling high-strength and high-modulus polyethylene fiber of the present invention has a contact coolness Qmax of more than 0.4W / cm2, and utilizes high thermal conductivity to achieve a higher contact coolness. If the contact coolness is less than 0.4W / cm2, the characteristic of high coolness cannot be achieved. The fiber has a breaking strength of more than 10cN / dtex, an elastic modulus of more than 400cN / dtex, and an elongation at break of less than 6%, which meets the characteristics of high strength and high modulus and achieves characteristics such as tensile strength and high performance. If the breaking strength is less than 10cN / dtex, high strength cannot be achieved; if the elastic modulus is less than 400cN / dtex, high modulus cannot be achieved; if the elongation at break is greater than 6%, it is difficult to obtain a higher crystal orientation and it is difficult to achieve high strength and high modulus. The characteristics of high strength and high modulus are used to achieve high wear resistance. The fiber intrinsic viscosity is 1.5~10dl / g to maintain the melt spinning processability and high strength and high modulus characteristics of the polyethylene fiber. A high molecular weight polyethylene raw material with an intrinsic viscosity of 3.5-10dl / g and a weight-average molecular weight to number-average molecular weight ratio (Mw / Mn) of 5-10 is melted and conveyed through a low-shear, high-conveyance screw extruder, and then enters a spinning assembly with a combined spinneret; a combined spinneret that can orient the polyethylene melt macromolecules and release the elastic potential energy of the melt is used to extrude filaments to obtain spun fibers; the spun fibers are subjected to multi-stage stretching and heat setting to produce finished high-cooling, high-strength, and high-modulus polyethylene fibers.

[0026] The polylactic acid elastic fiber and high-strength, high-modulus polyethylene fiber of the present invention are blended in a ratio of 3:7 to 7:3. Within this ratio, good comfort, wear resistance, and a cool feeling are achieved. A blending ratio below 3:7 results in poor elasticity and comfort, while a blending ratio above 7:3 results in poor wear resistance and a cool feeling.

[0027] In the manufacturing method for comfortable antimicrobial protective clothing fabric, the electron beam irradiation grafting modification method with cationic functional groups involves: a blend of the antimicrobial modified polylactic acid elastic fiber and high-strength, high-modulus polyethylene fiber undergoes a hydrophilic pretreatment and is then padded in a solution containing a cationic functional group monomer at a concentration of 20% to 100%. The padded fabric is then electron beam irradiated at a dose of 30 to 80 kGy. The padding and irradiation steps are repeated two to three times, and after irradiation, ungrafted monomers are removed with an organic solvent. Polylactic acid and polyethylene fibers have relatively low hydrophilicity. Pretreatment with a mixed solution containing a lipase and a nonionic surfactant improves the fabric's hydrophilicity and facilitates subsequent padding. Lipase treatment generates polar groups on the substrate surface, increasing its hydrophilicity. Furthermore, lipase hydrolysis occurs only on the substrate surface, with minimal impact on the physical and mechanical properties. While surface modification with lipase alone takes a long time, the addition of a surfactant can effectively reduce the lipase treatment time. Membranous microorganisms such as bacteria, fungi, and enveloped viruses all have negative charges on their membranes. The present invention covalently grafts monomers with cationic functional groups onto blended fabrics, creating electrostatic adsorption between the microorganisms. Following adsorption, the lipophilic portion of the grafted monomer can penetrate the membrane, disrupting it and eliminating the microorganisms. This achieves an antibacterial effect. A liquid volume less than 20% is difficult to achieve a good grafting effect, while a volume greater than 100% is prone to poor grafting uniformity. Repeating the padding process two to three times followed by electron beam irradiation can achieve a grafting rate of 10 to 30%, achieving a good antibacterial effect. At this grafting rate, both antibacterial and long-lasting antibacterial properties are relatively good. In the method for manufacturing comfortable antibacterial protective clothing fabrics, the monomers with cationic functional groups are preferably vinyl cationic monomers.

[0028] The following examples are given to specifically illustrate the fiber and the preparation method of the present invention.

[0029] The following evaluations were performed in Examples and Comparative Examples:

[0030] (1) Intrinsic viscosity

[0031] With reference to GB / T 10247-2008 standard, the intrinsic viscosity was measured using a fully automatic Ubbelohde viscometer IV3400X manufactured by Hangzhou Zhuoxiang, with the unit being dl / g.

[0032] (2) Fiber breaking strength, breaking elongation and fiber elastic modulus

[0033] The stress-strain curve was measured using a tensile testing machine "Tensilon" manufactured by Intech, with a sample length of 20 cm and a tensile speed of 100% / min. The load at break was read and divided by the initial fineness to calculate the breaking strength. The deformation at break was read and divided by the sample length, and the resulting value was multiplied by 100 to calculate the breaking elongation. The stress-strain curve was also used to calculate the Young's modulus using the fiber density and fineness. All these values ​​were obtained by repeating the operation five times using the same standard and calculating the simple average of the results. The breaking strength was rounded to the second decimal place, and the breaking elongation was rounded to the decimal place. The fiber elastic modulus was calculated from the tangent line with the maximum gradient near the origin of the stress-strain curve.

[0034] (3) Cool feeling when touching fibers and fabrics

[0035] With reference to GB / T 35263-2017 standard, the KES-QM contact cooling tester was used to make the fibers into woven fabric test pieces, and the contact cooling Qmax was tested in W / cm2.

[0036] (1) Antibacterial properties of fabrics

[0037] Refer to GB / T 20944.3-2008 oscillation method to test antibacterial properties.

[0038] (2) Fabric wear resistance

[0039] Refer to GB / T 21196-2007 standard to test the wear resistance level.

[0040] (3) Fabric elasticity (thickness characterization)

[0041] The thickness of woven fabrics was tested according to JIS 1096-2010.

[0042] The present invention will be described in detail below based on embodiments.

[0043] Example 1

[0044] A fabric is made by blending 5 parts of a high-cooling, high-strength, high-modulus polyethylene fiber (10 parts total), which has a contact coolness Qmax of 0.51 W / cm², a breaking strength of 18 cN / dtex, an elastic modulus of 700 cN / dtex, an elongation at break of 4.8%, and an intrinsic viscosity of 5.4 dl / g, with 5 parts of a PLA / PLA elastic fiber. The PLA / PLA elastic fiber is made from two PLA raw materials with different viscosities: raw material 1 (high-viscosity PLA) with an intrinsic viscosity of 1.5 dl / g and raw material 2 (low-viscosity PLA) with an intrinsic viscosity of 0.8 dl / g. The POY is melt-spun at 230°C and a spinning speed of 2800 m / min, and then texturized in a hot oven at 110°C.

[0045] The fabric was repeatedly dipped three times in a solution containing a vinyl cationic quaternary ammonium salt monomer, and irradiated with an electron beam irradiation process (absorbed dose) of 40 kGy to obtain a finished comfortable antibacterial protective clothing fabric.

[0046] The fabric was tested for its performance and found to have good cooling, wear resistance, and elasticity, as well as excellent antibacterial properties. The results are shown in Table 1.

[0047] Example 2

[0048] According to the total of 10 parts, 3 parts of high-cooling high-strength high-modulus polyethylene fiber and 7 parts of PLA / PLA elastic fiber are used, and the rest are obtained according to the process of Example 1 to obtain the finished product comfortable antibacterial protective clothing fabric.

[0049] The fabric was tested for its performance and found to have good cooling, wear resistance, and elasticity, as well as excellent antibacterial properties. The results are shown in Table 1.

[0050] Example 3

[0051] According to the total of 10 parts, 7 parts of high-cooling high-strength high-modulus polyethylene fiber and 3 parts of PLA / PLA elastic fiber are used, and the rest are obtained according to the process of Example 1 to obtain the finished product comfortable antibacterial protective clothing fabric.

[0052] The fabric was tested for its performance and found to have good cooling, wear resistance, and elasticity, as well as excellent antibacterial properties. The results are shown in Table 1.

[0053] Examples 4 and 5

[0054] According to the raw material 1 (high viscosity PLA) of PLA / PLA elastic fiber, the intrinsic viscosity was changed to 1.2 dl / g (Example 4) and 1.7 dl / g (Example 5), and the rest were obtained according to the process of Example 1 to obtain the finished comfortable antibacterial protective clothing fabric.

[0055] The fabric was tested for its performance and found to have good cooling, wear resistance, and elasticity, as well as excellent antibacterial properties. The results are shown in Table 1.

[0056] Examples 6 and 7

[0057] According to the raw material 2 (low-viscosity PLA) of PLA / PLA elastic fiber, the intrinsic viscosity was changed to 0.6 dl / g (Example 6) and 1.1 dl / g (Example 7), and the rest was carried out according to the process of Example 1 to obtain the finished comfortable antibacterial protective clothing fabric.

[0058] The fabric was tested for its performance and found to have good cooling, wear resistance, and elasticity, as well as excellent antibacterial properties. The results are shown in Table 1.

[0059] Example 8

[0060] The finished product of comfortable antibacterial protective clothing fabric was obtained by treating with an electron beam irradiation process (absorbed dose) of 30 kGy and following the process of Example 1.

[0061] The fabric was tested for its performance and found to have good cooling, wear resistance, and elasticity, as well as excellent antibacterial properties. The results are shown in Table 1.

[0062] Comparative Example 1

[0063] According to the total of 10 parts, 2 parts of high-cooling high-strength high-modulus polyethylene fiber and 8 parts of PLA / PLA elastic fiber are used, and the rest are obtained according to the process of Example 1 to obtain the finished product comfortable antibacterial protective clothing fabric.

[0064] The fabric was tested for its performance and found that while it had good elasticity and antibacterial properties, it had poor cooling and abrasion resistance, failing to achieve the desired protective effect. The results are shown in Table 2.

[0065] Comparative Example 2

[0066] According to the total of 10 parts, 8 parts of high-cooling high-strength high-modulus polyethylene fiber and 2 parts of PLA / PLA elastic fiber are used, and the rest are obtained according to the process of Example 1 to obtain the finished product comfortable antibacterial protective clothing fabric.

[0067] The fabric was tested for its performance and found that while it had good cooling, abrasion resistance, and antibacterial properties, it had poor elasticity and could not achieve the desired comfort effect. The results are shown in Table 2.

[0068] Comparative Examples 3 and 4

[0069] According to the raw material 1 (high viscosity PLA) of PLA / PLA elastic fiber, the intrinsic viscosity was changed to 1.8 dl / g (Comparative Example 3) and 1.1 dl / g (Comparative Example 4), and the rest were obtained according to the process of Example 1 to obtain the finished comfortable antibacterial protective clothing fabric.

[0070] In Comparative Example 3, when spinning PLA / PLA elastic fibers, high-viscosity PLA had poor fluidity, was easily broken, and had poor spinnability, and finished fibers and fabrics could not be obtained.

[0071] The fabric obtained in Comparative Example 4 was tested for its performance. It was found that while it had good cooling, abrasion resistance, and antibacterial properties, it had poor elasticity and could not achieve the desired comfort effect. The results are shown in Table 2.

[0072] Comparative Examples 5 and 6

[0073] According to the raw material 2 (low-viscosity PLA) of PLA / PLA elastic fiber, the intrinsic viscosity was changed to 0.5 dl / g (Comparative Example 5) and 1.2 dl / g (Comparative Example 6), and the rest were obtained according to the process of Example 1 to obtain the finished comfortable antibacterial protective clothing fabric.

[0074] In Comparative Example 5, low-viscosity PLA could not be formed during the spinning of PLA / PLA elastic fibers, and the spinnability was poor, so no finished fibers or fabrics could be obtained.

[0075] The fabric obtained in Comparative Example 6 was tested for its performance. It was found that while it had good cooling, wear resistance, and antibacterial properties, it had poor elasticity and could not achieve the desired comfort effect. The results are shown in Table 2.

[0076] Comparative Example 7

[0077] The finished fabric was obtained by the process of Example 1 with the padding liquid amount of 10%.

[0078] Testing the fabric's performance revealed that while it exhibited good cooling, abrasion resistance, and elasticity, its antibacterial properties were poor. The results are shown in Table 2.

[0079] Comparative Example 8

[0080] The electron beam irradiation process (absorbed dose) was 15 kGy, and the other processes were the same as in Example 1 to obtain the finished fabric.

[0081] Testing the fabric's performance revealed that while it exhibited good cooling, abrasion resistance, and elasticity, its antibacterial properties were poor. The results are shown in Table 2.

[0082] Comparative Example 9

[0083] The blended fabric obtained in Example 1 was coated with silver ions and padding three times to obtain a finished fabric.

[0084] Testing the fabric's performance revealed that while it exhibited good cooling, abrasion resistance, and elasticity, its antibacterial properties were poor. The results are shown in Table 2.

Claims

1. A method for manufacturing a comfortable antibacterial protective clothing fabric, characterized in that: The fabric is obtained by blending polylactic acid elastic fiber and high-cooling high-strength high-modulus polyethylene fiber, and then undergoing electron beam irradiation grafting modification. The following steps are involved: Preparation of polylactic acid elastic fibers; Antibacterial modified polylactic acid elastic fiber and high-cooling high-strength high-modulus polyethylene fiber are blended; The fabrics were modified by electron beam irradiation grafting with cationic functional groups; The preparation method of the polylactic acid elastic fiber is as follows: using polylactic acid raw materials with different intrinsic viscosities, raw material 1 is polylactic acid with an intrinsic viscosity of 1.2-1.7 dl / g, raw material 2 is polylactic acid with an intrinsic viscosity of 0.6-1.1 dl / g, spinning through a two-component melt spinning machine to obtain POY fiber, and low-temperature elasticizing to obtain antibacterial modified polylactic acid elastic fiber; the contact coolness Qmax of the high-cooling, high-strength, high-modulus polyethylene fiber is above 0.4 W / cm2; the fiber breaking strength is above 10 cN / dtex, the elastic modulus is above 400 cN / dtex, and the breaking elongation is below 6%; the fiber characteristics The viscosity is 1.5~10dl; the blending ratio of the antibacterial modified polylactic acid elastic fiber and the high-cooling high-strength and high-modulus polyethylene fiber is 3:7~7:3; the electron beam irradiation grafting modification method with cationic functional groups is as follows: the blended fabric of the antibacterial modified polylactic acid elastic fiber and the high-cooling high-strength and high-modulus polyethylene fiber is subjected to hydrophilic pretreatment, and then impregnated in a solution containing a cationic functional group monomer, with a liquid volume of 20%~100%; the impregnation operation is repeated 2~3 times, and then the impregnated fabric is subjected to electron beam irradiation under a process of 30~80kGy; after irradiation, the ungrafted monomer is removed with an organic solvent.

2. The method for manufacturing the comfortable antibacterial protective clothing fabric according to claim 1, characterized in that: The hydrophilic pretreatment step uses a hydrophilic pretreatment agent, which is a mixed solution of lipase and a non-ionic surfactant.

3. The method for manufacturing the comfortable antibacterial protective clothing fabric according to claim 1, characterized in that: The cationic functional group monomer is a vinyl cationic monomer.

4. A comfortable antibacterial protective clothing fabric, characterized in that: The comfortable antibacterial protective clothing fabric is made by the manufacturing method described in any one of claims 1 to 3.

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