Airtight protective clothing and processing technology thereof

Abstract

The invention discloses airtight protective clothing and a processing technology thereof. The protective clothing comprises a main body fabric, a sealing zipper and a protective mask, a three-dimensional composite sealing structure is arranged at a seam of the main body fabric, and the three-dimensional composite sealing structure sequentially comprises a hot melt adhesive lining layer made of a modified polyolefin elastomer, a hot melt adhesive lining layer and a sealing layer from inside to outside; the shape memory alloy wire mesh layer is formed by weaving nickel-titanium alloy wires into hexagonal honeycomb grids; according to the self-repairing polymer coating, light-cured polyurethane acrylate is used as a matrix, and nano silicon dioxide particles are doped; when the sulfydryl modified nano silicon dioxide particles in the self-repairing polymer coating are exposed to environmental ultraviolet light at a mechanical damage position, a dynamic disulfide bond exchange reaction can be triggered, cracks with the width smaller than or equal to 100 microns can be automatically closed within 5-30 min, the airtight performance recovery rate after repairing is larger than or equal to 95%, and therefore protection failure caused by tiny damage extension is avoided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of airtight protective clothing, and particularly relates to airtight protective clothing and a processing technology thereof. BACKGROUND

[0002] As core protective equipment in high-risk operation environments (such as bio-chemical pollution disposal, nuclear radiation areas, virus laboratories, etc.), the core function of airtight protective clothing is to achieve absolute isolation of the human body from the external environment while maintaining the basic activity ability of the human body. Such protective clothing needs to meet the aerosol sealing standard and also has properties such as resistance to chemical and biological erosion, resistance to mechanical puncture, and long-term wearing comfort. The existing technology usually uses a multi-layer composite fabric combined with a sealing zipper to form a protective main body, and the joint area is processed by a hot melt adhesive tape, high-frequency welding or sewing film coating process. With the complication of the operation environment (such as extreme temperature, highly corrosive medium, and large-scale limb movement), the dynamic sealing reliability of the joint of the protective clothing becomes a key technical bottleneck to protect the life safety of the operator.

[0003] Traditional hot melt adhesive tapes are prone to brittle and fall off in low temperature environments and prone to softening and creep in high temperature environments, and cannot adapt to the periodic stretching / compression caused by the joint movement of the human body. After 1000 times of repeated bending and stretching, the leakage of the joint will increase to 8-10 times of the initial value, which poses a major safety hazard. At the same time, micron-level mechanical damage (such as sharp object scratching and material aging cracks) will continuously expand and damage the airtight layer. The existing technology relies on external repair patches for post-processing, but cannot achieve in-situ self-repairing of damage during operation, thereby leading to rapid diffusion of local leakage points.

[0004] Therefore, in view of the above problems, the present application provides an airtight protective clothing and a processing technology thereof. SUMMARY

[0005] The present application aims to solve the above technical problems in the prior art and provides an airtight protective clothing and a processing technology thereof, which overcomes the problem that the joint of the existing protective clothing leads to sealing failure and damage that cannot be self-repaired under long-term deformation. By using a three-dimensional composite sealing structure with temperature response characteristics and combining hot pressing and laser composite manufacturing technology, good airtightness and micro-damage repair of the joint area during human activity are achieved, thereby fundamentally improving the reliability and service life of the protective clothing under extreme working conditions.

[0006] To solve the above technical problems, the present application adopts the following technical solutions:

[0007] An airtight protective clothing comprises a main body fabric, a sealing zipper and a protective mask.

[0008] A three-dimensional composite sealing structure is arranged at the joint of the main body fabric, and the three-dimensional composite sealing structure comprises, from inside to outside:

[0009] a hot melt adhesive inner lining layer made of modified polyolefin elastomer, with a thickness of 0.3-0.5mm;

[0010] a shape memory alloy wire mesh layer made of nickel-titanium alloy wires woven into a hexagonal honeycomb mesh with a mesh aperture of 0.8-1.2mm;

[0011] a self-repairing polymer coating layer with light-cured polyurethane acrylate as the base material and doped with nano-silica particles.

[0012] Further, the shape memory alloy wire mesh layer has a transition temperature of 35-40℃, and when the temperature is ≥40℃, the mesh shrinkage rate is 12-15% of the original size.

[0013] Further, the nano-silica particles in the self-repairing polymer coating layer have a surface grafted with mercapto groups, with a particle size of 50-80nm and a doping mass fraction of 8-12%.

[0014] A processing technology for airtight protective clothing, comprising the following steps:

[0015] S1, using a numerical control cutting machine to cut the main fabric, and reserving an overlapping area with a width of 10mm at all seam edges, which is used to form a three-dimensional composite sealing structure subsequently;

[0016] S2, forming a three-dimensional composite sealing structure by a hot pressing method combined with a laser composite process;

[0017] S3, assembling the fabric assembly treated with seams with a sealing zipper and a protective mask.

[0018] Further, step S2 specifically comprises the following steps:

[0019] S21, coating a hot melt adhesive inner lining layer on the seam overlapping area, and hot pressing by a curved hot pressing die with temperature control at 120-130℃ and a pressure of 0.5MPa;

[0020] S22, laying a shape memory alloy wire mesh layer on the surface of the hot melt adhesive layer, and positioning and welding the mesh by a multi-frequency laser, with a laser wavelength of 1064nm and a pulse energy of 15-20J / cm 2 ;

[0021] S23, spraying a self-repairing polymer coating layer on the surface of the alloy wire mesh layer, and curing by a ultraviolet light curing device at a wavelength of 365nm and an intensity of 80-100mW / cm 2 for 30-60s.

[0022] Further, the working surface of the curved hot pressing die is a shaped curved surface with a curvature radius matching the joint part of the protective clothing, with an error of ≤±0.1mm, and the die is provided with a temperature sensor inside to adjust the surface temperature in real time.

[0023] Further, the multi-frequency laser comprises an infrared laser head and a green laser head, the infrared laser head is used for fusion welding of the alloy wire mesh layer, and the green laser head is used for real-time monitoring of deformation of a welding area, and the precision reaches 0.05 mm.

[0024] Further, in the positioning and welding step in step S22, a path compensation algorithm is used, point cloud coordinate data is acquired by scanning a joint surface through a high-precision 3D vision system, the offset amount of the laser focal point is adjusted based on curvature variation, the offset amount Δd is calculated according to the formula: Δd=k·(1 / R_max-1 / R_min), and finally the infrared laser head of the multi-frequency laser is driven to adjust the focal point position along the surface normal, wherein k is a material compensation coefficient, the value is 0.2-0.3, and R_max and R_min are the maximum and minimum curvature radii of the current path segment.

[0025] Further, the green laser head emits 532nm laser during the welding monitoring process, the laser generates reference light and measurement light through a beam splitter, the measurement light forms a reflected interference field after irradiating the welding area of the shape memory alloy wire mesh layer, the phase offset Δφ of the interference fringes is analyzed, the micro-strain ε is calculated according to the formula: ε=(λ / 4π)·(Δφ / d), wherein d is the optical path difference, and when the detection value exceeds a preset threshold value, a welding interruption program is automatically triggered.

[0026] Further, the ultraviolet curing device in step S3 is provided with a rotating mechanism, so that the joint of the protective clothing rotates along the axis at a speed of 2-5 rpm.

[0027] The present application has the following beneficial effects due to the adoption of the above technical solutions:

[0028] 1. When the mercapto-modified nano-silica particles in the self-repairing high molecular coating of the present application are exposed to environmental ultraviolet light (280-400nm) at a mechanical damage site, a dynamic disulfide bond exchange reaction is triggered, cracks with a width of ≤100μm are self-closed within 5-30min, and after repair, the air tightness recovery rate is ≥95%, thereby avoiding the expansion of small damages and leading to protection failure.

[0029] 2. Based on the three-dimensional composite sealing structure and the shape memory alloy wire mesh layer, when the joint of the protective clothing is stretched due to joint bending, the body temperature triggers the alloy layer to shrink by 12-15% at 35-40℃, and the deformed gap is actively filled by the hot melt adhesive lining layer, thereby greatly reducing the leakage amount of the joint, thereby ensuring the air tightness stability during intense exercise.

[0030] 3, The profiled curved surface hot pressing die of the present application matches a temperature sensor, realizes the uniformity of the hot pressing temperature of the joint area 120-130 DEG C, thereby eliminating the micro-hole defects caused by local temperature difference, and the path compensation algorithm of the present application can dynamically adjust the laser focal point, thereby greatly improving the curvature mutation area of the alloy wire mesh layer in the shoulder / knee part. BRIEF DESCRIPTION OF DRAWINGS

[0031] The present application will be further described below in conjunction with the drawings:

[0032] Figure 1 The process flow chart of the present application is a gas-tight protective clothing processing process. DETAILED DESCRIPTION

[0033] The present application is a gas-tight protective clothing comprising a main body fabric, a sealing zipper and a protective mask

[0034] The joint of the main body fabric is provided with a three-dimensional composite sealing structure, which comprises, from inside to outside:

[0035] The hot melt adhesive inner lining layer is made of modified polyolefin elastomer, and the thickness is 0.3-0.5mm;

[0036] The shape memory alloy wire mesh layer is woven into a hexagonal honeycomb grid by nickel-titanium alloy wire, and the grid aperture is 0.8-1.2mm;

[0037] The self-repairing high molecular coating is based on light-cured polyurethane acrylate, and doped with nano silicon dioxide particles.

[0038] Further, the main body fabric selects polytetrafluoroethylene or polyester fiber composite film as the material, and is cut into front chest, back and limb components by a cutting machine according to a three-dimensional digital model, all joint edges are provided with 10mm overlapping area, the protective mask is made of polycarbonate, the three-dimensional composite sealing structure is arranged in the joint overlapping area, and from inside to outside, it is: the hot melt adhesive inner lining layer is coated with modified POE glue particles to form a uniform glue film with a thickness of 0.3-0.5mm, the shape memory alloy wire mesh layer uses nickel-titanium alloy to lay a hexagonal grid, and the self-repairing high molecular coating sprays light-cured polyurethane acrylate prepolymer containing 10wt% mercapto modified SiO2 nano particles.

[0039] As shown in Figure 1 A processing process of a gas-tight protective clothing, comprising the following steps:

[0040] S1, a numerical control cutting machine is used to cut the main body fabric, and an overlapping area with a width of 10mm is reserved at all joint edges, which is used for subsequent formation of a three-dimensional composite sealing structure;

[0041] S2, coating the hot melt adhesive inner lining layer in the seam overlap area, hot pressing molding at 120-130℃ and 0.5MPa pressure through a curved surface hot pressing mold with temperature control, laying a shape memory alloy wire mesh layer on the surface of the hot melt adhesive layer, and performing grid positioning welding using a multi-frequency laser, the laser wavelength is 1064nm, and the pulse energy is 15-20J / cm 2 Spraying a self-repairing polymer coating on the surface of the alloy wire mesh layer, and curing the coating through a UV curing device at a wavelength of 365nm and an intensity of 80-100mW / cm 2 for 30-60s;

[0042] S3, assembling the seam-processed fabric assembly with a sealing zipper and a protective mask.

[0043] Further, the hot pressing and laser composite process of the present application is described as follows:

[0044] The working surface of the curved surface hot pressing mold is a concave surface with a curvature radius of 35mm and a processing error of not more than ±0.1mm, and the inside of the mold is embedded with fiber Bragg grating sensing units at an interval of every 5mm to form a temperature monitoring array, the sensing units are connected to an external demodulator through a single-mode optical fiber to feedback the surface temperature of the mold in real time, the multi-frequency laser is equipped with an infrared laser emitter and a green laser emitter, the infrared laser head outputs a wavelength of 1064nm and the pulse energy can be adjusted in the range of 15-20J / cm 2 , and the green laser head outputs a continuous laser with a wavelength of 532nm; the UV curing device includes a matrix of ultraviolet light emitting diodes arranged in a ring and a rotating clamping mechanism driven by a servo motor, the central wavelength of the ultraviolet light source is 365nm, and the irradiation intensity is stably maintained at 80 to 100mW / cm 2 , the rotating mechanism drives the seams of the protective clothing to rotate at a uniform speed of 2-5rpm / min, and the radial runout is less than 10μm; the workpieces are automatically transferred between the three devices by a mechanical arm, the hot pressing mold is set to a working temperature of 125℃ and a pressure of 0.5MPa, the welding path of the multi-frequency laser is guided by a three-dimensional vision system and performs a curvature compensation algorithm, and the UV curing time is 30-60s, finally realizing continuous production of seam processing.

[0045] Further, the processing flow of the seam is described as follows:

[0046] A modified polyolefin elastomer hot melt adhesive is applied to the overlapping area of ​​the seam to form a 0.4mm thick inner lining layer. The fabric is placed in a curved hot press mold, subjected to a pressure of 0.5MPa, and hot-pressed at 125℃ for 60 seconds. The fiber Bragg grating array inside the mold provides real-time feedback on temperature fluctuations, thereby controlling the temperature within ±2℃. After hot pressing, the fabric is transferred to the laser station by a robotic arm. A hexagonal mesh layer of NiTi-01 nickel-titanium alloy is laid on the adhesive layer surface. Point cloud data of the curved surface of the seam is acquired through a 3D vision system. Based on the minimum and maximum curvature radii of 8mm and 45mm, the focal offset is calculated to be 0.024mm using the formula Δd=0.25×(1 / 8-1 / 45). The multi-frequency laser infrared laser head operates at a wavelength of 1064nm and a laser speed of 18J / cm². 2 The alloy mesh nodes were welded using pulsed energy, and a 532nm green laser head was simultaneously activated to monitor the welding strain. When the detected value exceeded 50με, the pulse frequency was automatically reduced to 200Hz. Immediately after welding, a photocurable polyurethane coating of silica nanoparticles was sprayed on, with a wet film thickness of 80μm. Subsequently, it was placed in an ultraviolet curing device at a wavelength of 365nm and a wavelength of 90mW / cm². 2 The device is exposed to light at a speed of 3 rpm for 45 seconds to complete the curing process.

[0047] Furthermore, the assembly and testing of protective clothing will be explained in detail:

[0048] After the seams of the protective suit's main fabric are treated, it is assembled with a sealing zipper. Molten modified POE granules are injected into the zipper teeth, and a second hot-press sealing process is performed using a hot press mold at 125°C and 0.5MPa pressure for 30 seconds. A fluororubber O-ring is embedded in the annular groove on the flange end face of the protective mask. The outer surface is sprayed with a photocurable polyurethane coating containing 10wt% mercapto-based SiO2 nanoparticles, and then subjected to a 365nm wavelength and 90mW / cm² pressure. 2 The protective suit was cured by UV spin curing for 45 seconds. The finished suit was then placed in a 38°C constant temperature chamber, filled with 0.5MPa helium, and the overall leakage rate was detected using a mass spectrometer leak detector. Three verification tests were performed: the first, a dynamic sealing test, used a six-axis robotic arm to simulate a 90° elbow flexion and extension movement, cyclically performed 5000 times at a frequency of 1Hz, to detect its leakage rate; the second, a self-healing verification, involved creating an 80μm wide surface crack with a diamond blade and exposing it to 50mW / cm² water. 2 The crack closure rate was observed under a 365nm ultraviolet light source for 20 minutes. The third fatigue life test was conducted according to ISO 13994 standard, with 10,000 ±0.5kPa pressure difference cycles. Industrial CT scan showed zero fractures in the nickel-titanium alloy wire mesh layer and no peeling of the coating.

[0049] Furthermore, the control logic of this invention will be explained as follows:

[0050] The welding path compensation logic of the multi-frequency laser is as follows: the three-dimensional vision system collects the joint curved surface point cloud coordinates and transmits them to the path planning software, calculates the minimum curvature radius R_min and the maximum curvature radius R_max of the current path segment, calls the curvature compensation function to output the focal point offset in real time according to the formula Δd = 0.25 × (1 / R_min-1 / R_max), and when R_min = 8 mm and R_max = 45 mm, Δd = 0.024 mm is calculated. The infrared laser head is driven to adjust the focal point position along the curved surface normal.

[0051] The temperature control logic of the curved hot pressing mold is as follows: the fiber Bragg grating sensor array collects the wavelength drift Δλ every 5 mm, the demodulator converts the temperature deviation according to the formula ΔT = Δλ / (6.5 × 10-6 × 1550), and the PID output adjusts the amount to the heating unit to maintain the mold surface temperature at 125 ± 2 ℃.

[0052] The strain monitoring logic of the green laser head is as follows: the reflected light in the welding area is collected to generate interference fringes, the image processor analyzes the phase shift Δφ of the fringes, calculates the micro-strain value according to the formula ε = (5.32 × 10-4) / (4 × 3.14) × (Δφ / 12.5), and sends an interrupt instruction to the laser power module when the real-time detection value exceeds the preset threshold value 200 με.

[0053] Further, the present application provides an embodiment:

[0054] In this embodiment, a 0.25 mm thick polytetrafluoroethylene composite film is selected for the preparation of airtight protective clothing, which is cut into components by numerical control and has a 10 mm joint overlap area. A three-dimensional composite sealing structure is constructed in the overlap area: a 0.4 mm thick hot melt adhesive inner layer is formed by scraping POE particles, a curved mold with a curvature radius of 35 ± 0.1 mm is used for hot pressing at 125 ℃ and 0.5 MPa for 60 seconds, and then a metal mesh layer with a pore size of 1.0 mm is laid. The point cloud data is obtained by scanning the joint curve with a 3D vision system, the focal point offset is calculated according to the formula Δd = 0.25 × (1 / 8-1 / 45) = 0.024 mm, and the multi-frequency laser is used at a wavelength of 1064 nm and a pulse energy of 18 J / cm 2 The pulse energy welds the grid nodes, and the synchronous 532 nm green laser monitors the strain value in real time, which is less than 200 με. After welding, a light-cured polyurethane coating containing 10 wt% mercapto-modified 60 nm silica particles is sprayed, the wet film thickness is 80 μm, and the coating is cured by 365 nm wavelength 90 mW / cm 2 The ultraviolet light is rotated at a speed of 3 rpm and cured for 45 seconds, with a cumulative light energy of 4.05 J / cm 2 After assembling the fluororubber double-tooth zipper and the polycarbonate mask, the initial leakage rate is 0.005% at 0.5 MPa helium pressure in a 38 ℃ environment, the leakage rate increases to 0.007% after 5000 times of 90° bending and stretching test by a mechanical arm, and the 80 μm wide knife mark is cured by 50 mW / cm2 UV irradiation for 20 minutes microscopic observation of the closure rate of 98%, industrial CT scan shows the seam micro-hole defect rate of 0.2 / m.

[0055] Further, the present application provides a comparative example:

[0056] Select commercially available heat sealing process protective clothing as a comparative example and the product of the present embodiment for four parallel tests, dynamic sealing test using the same six-axis robot to perform elbow 90° flexion movement, frequency 1Hz cycle 5000 times, the comparative example leakage rate of 0.041% while the present embodiment is 0.007%, leakage reduction of 82.9%; micro-crack repair test using diamond blade in two types of sample surface preparation width 80μm crack, the present embodiment exposed to 50mW / cm 2 intensity 365nm UV light for 20 minutes after microscopic observation of the crack closure rate of 98%, the comparative example without self-repair function; accelerated aging test according to ISO 13994 standard in 85℃ / 95%RH environment, the comparative example 1500 hours appear adhesive layer peeling, the present embodiment >5000 hours without failure; seam defect rate detection by industrial CT scan 1 meter length of the seam area, the comparative example found 8.3 micro-hole defects, the present embodiment only 0.2, the defect rate decreased by 97.6%, see table 1:

[0057] Table 1 comparison test table

[0058]

[0059]

[0060] The above is only a specific embodiment of the present application, but the technical features of the present application are not limited to this. Any simple change, equivalent replacement or modification made on the basis of the present application to solve the same technical problems and achieve the same technical effects, are all covered by the protection scope of the present application.

Claims

1. A gas-tight protective suit, characterized in that: The utility model relates to a kind of protective clothing, including main body fabric, sealed zipper and protective mask;Suture of the main body fabric is provided with three-dimensional composite sealing structure, the three-dimensional composite sealing structure includes sequentially from inside to outside: Hot melt adhesive lining layer, material is modified polyolefin elastomer, thickness 0.3-0.5mm; Shape memory alloy wire mesh layer, woven into hexagonal honeycomb grid by nickel-titanium alloy wire, grid aperture 0.8-1.2mm; Self-repairing high molecular coating, with light-cured polyurethane acrylate as matrix, doped with nano-silica particles.

2. A gas- impermeable protective suit according to claim 1, characterized in that: The transition temperature of the shape memory alloy wire mesh layer is 35-40℃, and the grid shrinkage rate is 12-15% of the original size when the temperature is greater than or equal to 40℃.

3. A gas- impermeable protective suit according to claim 1, characterized in that: The nano-silica particles of the self-repairing high molecular coating have mercapto groups grafted on the surface, and the particle size is 50-80nm, and the doping mass fraction is 8-12%.

4. The process for manufacturing a gas-tight protective suit according to any one of claims 1 to 3, characterized in that, The utility model relates to a kind of protective clothing, including the following steps: S1, using numerical control cutting machine to cut main body fabric, and reserve the width of 10mm overlap area in all seam edges, which is used for subsequent formation of three-dimensional composite sealing structure; S2, form three-dimensional composite sealing structure by hot-pressing and laser composite process; S3, the fabric assembly treated with seam is assembled with sealed zipper and protective mask.

5. The process for manufacturing a gas- impermeable protective suit according to claim 4, characterized in that: The step S2 specifically includes the following steps: S21, coat hot melt adhesive lining layer in seam overlap area, and form by hot-pressing mold with temperature control at 120-130℃ and 0.5MPa pressure; S22, lay the shape memory alloy wire mesh layer on the surface of the hot melt adhesive layer, use multi-frequency laser for grid positioning welding, laser wavelength 1064 nm, pulse energy 15-20 J / cm 2 ; S23, spray self-repairing polymer coating on the surface of the alloy mesh layer, and cure it by UV light curing device at 365 nm wavelength and light intensity of 80-100 mW / cm 2 cure for 30-60 s.

6. The process for manufacturing a gas and fluid impermeable protective garment according to claim 5, wherein: The working surface of the curved hot-pressing mold is a contoured curved surface with a curvature radius matching the joint part of the protective clothing, and the error is less than or equal to ±0.1mm. The mold is provided with a temperature sensor inside to adjust the surface temperature in real time.

7. The process for manufacturing a gas and fluid impermeable protective garment according to claim 1, wherein: The multi-frequency laser includes an infrared laser head and a green laser head. The infrared laser head is used for fusion welding of the alloy wire mesh layer, and the green laser head is used for real-time monitoring of the deformation of the welding area with an accuracy of 0.05mm.

8. The process for manufacturing a gas and fluid impermeable protective garment according to claim 5, wherein: In the positioning and welding step of step S22, a path compensation algorithm is used. First, a high-precision 3D vision system is used to scan the seam curve to obtain point cloud coordinate data. Based on the curvature change, the offset of the laser focus is adjusted. The offset Δd calculation formula is: Δd=k·(1 / R_max-1 / R_min), where k is the material compensation coefficient, and the value is 0.2-0.

3. R_max and R_min are the maximum and minimum curvature radii of the current path segment. Finally, the infrared laser head of the multi-frequency laser is driven to adjust the focus position along the normal of the curved surface.

9. The process for manufacturing a gas- impermeable protective suit according to claim 7, wherein: During the welding monitoring process, the green laser head emits 532nm laser. The laser generates reference light and measurement light through a beam splitter. After the measurement light irradiates the welding area of the shape memory alloy wire mesh layer, a reflected interference field is formed. By analyzing the phase shift Δφ of the interference fringes, the micro-strain ε is calculated according to the formula ε=(λ / 4π)·(Δφ / d), where d is the optical path difference. When the detected value exceeds the preset threshold, the welding interruption program is automatically triggered.

10. The process for manufacturing a gas and fluid impermeable protective garment according to claim 5, wherein: The ultraviolet curing device of step S3 is equipped with a rotating mechanism to make the protective clothing seam rotate along the axis at a speed of 2-5rpm.

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