High-barrier ultrasonic sewing method for film cloth composite surgical gown

Abstract

The application discloses a kind of film cloth composite type surgical gown with high barrier ultrasonic sewing method.The PVA composite fabric formed by PVA non-woven fabric and PVA film is selected in the application;The front of ultrasonic sewing welding head is connected with the humidity of mesh roller humidifying device, the PVA non-woven fabric in PVA composite fabric is humidified by mesh roller humidifying device, the humidity of PVA non-woven fabric is adjusted by changing the roughness of mesh roller surface;Ultrasonic sewing is carried out on the PVA composite fabric after humidification using ultrasonic sewing welding head, and the ultrasonic sewing process parameters suitable for PVA composite fabric are used to obtain film cloth composite type surgical gown.The PVA non-woven fabric is moderately humidified, the water content of PVA non-woven fabric is controlled, the PVA fiber can be plastic deformation at lower temperature, and the processing requirements of PVA composite fabric with different thickness and film cloth composite ratio are met by combining the ultrasonic vibration effect.

Description

Technical Field

[0001] This invention belongs to the field of medical supplies technology, specifically a high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns. Background Technology

[0002] In recent years, the medical industry has widely adopted polypropylene SMS material as disposable surgical gowns, which are lightweight, breathable, and offer good protection against bacteria. However, for protection against viruses, highly pathogenic bacteria, and toxic drugs, membrane-fabric composite materials are the safest protective materials. Composite surgical gowns feature an inner fabric layer that allows for slight sweat absorption and wicking, while the outer membrane layer effectively blocks the penetration of blood, bodily fluids, and viruses, reducing the occupational exposure risk for healthcare workers. Furthermore, the composite fabric has stronger tear and abrasion resistance, making it less prone to damage during surgery due to friction or pulling, thus preventing protective failure caused by clothing tearing.

[0003] In terms of comfort, SMS-like materials made from ordinary polymers have a clear advantage. However, for non-woven surgical gowns to have good barrier properties, they need excellent water repellency. This means that the sweat secreted by medical staff during the wearing process cannot be absorbed, leading to extreme stuffiness if the surgery lasts too long. Ordinary membrane composites, on the other hand, are completely non-breathable, making the wearer very uncomfortable.

[0004] PVA (polyvinyl alcohol) materials are highly anticipated in the medical protective field due to their excellent biocompatibility, biodegradability, breathability, moisture permeability, and natural barrier function. The dense molecular chains of PVA film can effectively block bacteria, viruses, and other microorganisms, and its hydrophilicity gives it good moisture permeability. PVA nonwoven fabric has advantages such as softness, breathability, and quick-drying. The full PVA system fabric formed by the combination of the two is superior to traditional PE and PP composite fabrics in terms of environmental protection and protection, which is in line with the development trend of "green protection" in the medical field.

[0005] However, the unique thermal properties of PVA (thermal decomposition temperature of approximately 200℃, close to its melting temperature; prone to molecular chain breakage and carbonization at high temperatures, making effective bonding impossible through traditional hot-melt methods) pose a significant challenge to its use in ultrasonic sewing processes commonly used in surgical gowns. Current mainstream surgical gown sewing techniques and processing technologies for membrane-fabric composite fabrics have not yet resolved the sewing compatibility issue with PVA materials.

[0006] The principle of ultrasonic sewing is to use an ultrasonic generator to produce high-frequency mechanical vibrations (usually 20-40kHz), which are transmitted to the fabric seam through a welding head. The vibration energy is converted into localized heat, melting the fabric fibers or substrate. Simultaneously, pressure is applied to bond the molten parts, forming a stable seam structure. This process has gradually replaced some hot-press bonding processes due to its advantages such as high processing efficiency (0.1-1 second processing time per seam), no pinholes in the seam, and no need for additional adhesive layers. However, existing ultrasonic sewing processes are designed for easily heat-melting thermoplastic materials such as TPEE, PE, TPU, and PP, and do not consider the special properties of PVA, causing it to completely fail in the processing of PVA film-fabric composite fabrics. Specific problems are as follows: (1) Lack of material compatibility: The core of traditional ultrasonic sewing technology relies on the "vibration heat generation - thermal melting bonding" mechanism, which is suitable for thermoplastic materials. These materials will melt rapidly under the local high temperature of 80-120℃ generated by ultrasonic vibration, and the molecular chains will interpenetrate to form a stable bond. However, PVA material has special thermal properties. Its thermal decomposition temperature is close to the melting temperature. Under the local high temperature generated by ultrasonic vibration, PVA fibers will not melt, but will instead undergo molecular chain breakage and carbonization, which manifests as yellow or black scorch spots at the seam. The fiber strength and tensile strength at the seam will drop sharply, and the PVA film at the scorch spot will be damaged, forming new protective gaps and no longer having good barrier properties.

[0007] (2) Unreasonable design of pattern welding head: The existing ultrasonic sewing welding head pattern design is mainly divided into three categories: ① Pure closed pattern (such as continuous straight line pattern, sawtooth pattern), characterized by strong barrier properties, but the dense pattern leads to heat concentration. For PVA material, the local temperature is easy to exceed its thermal decomposition temperature, which aggravates fiber carbonization; ② Pure sparse pattern (such as dispersed dot pattern, radial pattern), which reduces heat accumulation and reduces the risk of thermal damage by dispersing the pattern, but the pattern is not continuous and cannot form a complete barrier. Especially for PVA material, its surface is highly hydrophilic and is prone to liquid leakage at the joint due to capillary effect; ③ Simple mixed pattern (such as "six virtual and one real" combination pattern, closed pattern and dot pattern splicing), which attempts to take into account both thermal damage control and barrier properties, but has not been optimized for material characteristics. For PVA material, the "real seam" part will still generate local high temperature leading to carbonization, while the "virtual seam" part cannot form an effective bond due to insufficient energy, and the joint is easy to detach, which cannot meet the level 4 protection requirements.

[0008] (3) Lack of adaptability of process parameters: The parameter range of the existing ultrasonic sewing process (vibration frequency 30-35kHz, pressure 0.4-0.6MPa, temperature 90-110℃, energy density 1.5-2.0J / mm²) is set based on the melting characteristics of thermoplastic materials. When used for PVA materials, a double contradiction will occur: if processed according to the existing parameters, high temperature and high pressure will cause PVA fiber carbonization and film damage; if the temperature, frequency and pressure are reduced, the PVA fiber cannot produce sufficient plastic deformation or bonding force, and the seam strength is extremely low, which cannot meet the usage requirements. In addition, the existing process does not consider the influence of fabric thickness and composite structure on parameters. For the composite structure of PVA nonwoven fabric + PVA film, the difference in thermal response between the film layer and the nonwoven fabric layer further aggravates the instability of seam quality.

[0009] In summary, existing ultrasonic surgical gown sewing processes cannot meet the processing requirements of PVA membrane composite fabrics. As a high-quality, environmentally friendly, and high-barrier medical protective material, the core bottleneck in the application and promotion of PVA lies in the lack of suitable sewing processes. Meanwhile, with the continuous improvement of medical protection requirements, the market demand for surgical gowns has upgraded from "basic protection" to "high protection + high comfort + environmental protection": requiring seams to meet Level 4 protection standards while ensuring that the seams are thin, soft, breathable, and comfortable to avoid affecting surgical procedures; requiring stable and reliable processes suitable for mass production while also meeting environmental protection requirements to reduce the pollution of the environment by medical waste.

[0010] Therefore, developing a specialized sewing process for PVA materials to overcome existing technological limitations has become an urgent need in the field of membrane-fabric composite surgical gowns. Summary of the Invention

[0011] To address the problems existing in the prior art, this invention provides a high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns. This method involves moderately humidifying the PVA nonwoven fabric, allowing the PVA fibers to undergo plastic deformation at lower temperatures, thus avoiding carbonization caused by high temperatures. Combined with ultrasonic vibration, this ultimately forms a stable structure of "physical interweaving + hydrogen bonding," replacing traditional thermal fusion bonding. This fundamentally solves the core problem of PVA's difficulty in melting, thus adapting to the processing needs of PVA composite fabrics with different thicknesses and membrane-fabric composite ratios.

[0012] To achieve the above objectives, the present invention adopts the following technical solution: a high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns, comprising: PVA composite fabric, made of PVA nonwoven fabric and PVA film, is selected. An adjustable humidity anilox roller humidification device is connected in series in front of the ultrasonic sewing welding head. The anilox roller humidification device humidifies the PVA nonwoven fabric in the PVA composite fabric. The humidity of the PVA nonwoven fabric is adjusted by changing the surface roughness of the anilox roller, thereby controlling the water content of the PVA nonwoven fabric. An ultrasonic sewing head was used to ultrasonically sew the humidified PVA composite fabric. Ultrasonic sewing process parameters adapted to the PVA composite fabric were adopted to obtain a membrane-fabric composite surgical gown.

[0013] An adjustable humidity anilox roller humidification device is connected in series in front of the ultrasonic sewing die head as the core pretreatment step before sewing PVA composite fabrics. This fundamentally solves the problem of PVA's difficulty in melting. The principle is as follows: PVA material has extremely strong hydrophilicity. Water molecules can form hydrogen bonds with PVA molecular chains. When moderately humidified, water molecules penetrate into the gaps between PVA fibers and are absorbed by the fibers, causing the fibers to swell. On the one hand, this lowers the glass transition temperature of PVA fibers, allowing them to undergo plastic deformation at lower temperatures and avoiding carbonization caused by high temperatures. On the other hand, under ultrasonic vibration, the moisture inside the fabric will generate a "cavitation effect," forming tiny bubbles that burst instantly. The release of local energy pressure will enhance the adhesion between fibers, ultimately forming a stable structure of "physical interweaving + hydrogen bonding," replacing traditional hot-melt bonding and fundamentally solving the core problem of PVA's difficulty in melting.

[0014] Furthermore, the water content of the PVA nonwoven fabric is preferably controlled to be between 1-30% by the anilox roller humidification device.

[0015] Furthermore, in the PVA composite fabric, the PVA nonwoven fabric has a basis weight of 25-70 g / m² to ensure softness and mechanical strength; the PVA film has a thickness of 0.01-0.06 mm and is prepared by casting process to ensure molecular chain compactness and barrier properties; the water content of the PVA nonwoven fabric is controlled at 5-20% by a gravure roller humidification device.

[0016] Furthermore, the anilox roller humidification device includes a water storage chamber, an anilox roller body, and a scraping assembly; The anilox roller body is installed on top of the water storage chamber, which contains deionized water. The lower half of the anilox roller body is immersed in the deionized water. The anilox roller body is connected to the drive motor via a coupling, and the drive motor drives the anilox roller body to rotate. The PVA composite fabric directly covers the upper half of the anilox roller body, and the rotation of the anilox roller body humidifies the PVA nonwoven fabric. The squeegee assembly is attached to the surface of the anilox roller body and is used to scrape off excess water from the surface of the anilox roller body to ensure the uniformity of liquid carrying volume in the mesh on the surface of the anilox roller body.

[0017] Furthermore, the anilox roller body is made of stainless steel, and the surface is laser-engraved to form uniformly distributed micron-level mesh holes with a mesh count range of 160-260 meshes, a mesh depth of 0.3-0.5 mm, and a mesh density of 200-300 holes / cm².

[0018] Mesh count and mesh density are two independent technical parameters and should not be equated or confused. Mesh count is defined as the number of mesh openings per inch (linear density, unit: mesh), used to characterize the size of the mesh openings; mesh density is defined as the total number of mesh openings per unit area (1 cm²) (area density, unit: openings / cm²), used to characterize the density of mesh opening distribution on the roller surface.

[0019] Furthermore, while adjusting the humidity of PVA nonwoven fabric by changing the surface roughness of the anilox roller, the difference between the rotational speed of the anilox roller body and the linear speed of the fabric is adjusted to control the amount of liquid applied, thereby providing auxiliary adjustment for the humidity of PVA nonwoven fabric.

[0020] The humidity regulation mechanism adopted in this invention is as follows: precise control of the water content of PVA fabric is achieved through dual regulation: ① The core regulation method is to change the roughness of the surface of the anilox roller body - the higher the roughness, the more water is adsorbed on the surface of the anilox roller body, and the higher the water content transferred to the PVA nonwoven fabric during rotation; ② The auxiliary regulation method is to adjust the difference between the rotation speed of the anilox roller body and the linear speed of the fabric - the greater the speed difference, the greater the liquid volume, and the smaller the speed difference, the smaller the liquid volume.

[0021] Furthermore, an ultrasonic sewing head combining sparse and closed patterns is used, with the pattern design depth adapted to the deformation characteristics and barrier requirements of PVA fibers after humidification, and the closed pattern is located on the outside of the sparse pattern.

[0022] Furthermore, the closed-type pattern is the main barrier band: a convex solid annular band; the dredging-type pattern is the auxiliary connecting band: a convex flow-guiding pattern formed by multiple rhombuses connected end to end; the auxiliary connecting band is parallel to the main barrier band.

[0023] Furthermore, the width of the sparse pattern is greater than the width of the closed pattern, with the width of the closed pattern being ≥1mm and the width of the sparse pattern being ≥2mm.

[0024] Furthermore, the ultrasonic sewing process parameters for PVA composite fabrics are as follows: Vibration frequency: 15kHz-30kHz; sewing pressure: 0.3MPa-0.6MPa; sewing speed: 2.5mm / s-5mm / s; energy density: 1.2J / mm²-1.8J / mm²; sewing method: planar overlapping welding, with alignment error of upper and lower fabric layers ≤0.5mm, ultimately forming a closed structure.

[0025] The beneficial effects of this invention are as follows: (1) The present invention moderately humidifies the PVA nonwoven fabric so that the PVA fibers can undergo plastic deformation at a lower temperature, avoiding carbonization caused by high temperature. Combined with the ultrasonic vibration, a stable structure of "physical interweaving + hydrogen bonding" is finally formed, replacing the traditional hot melt bonding. This solves the core problem of PVA being difficult to melt from the principle and adapts to the processing needs of PVA composite fabrics with different thicknesses and film-to-fabric composite ratios.

[0026] (2) The present invention achieves precise control of the water content of PVA fabric through a dual humidity regulation mechanism.

[0027] (3) The present invention uses an ultrasonic sewing head that combines closed-type patterns and open-type patterns. Compared with pure closed-type patterns, pure open-type patterns and some existing hybrid ultrasonic sewing heads on the market, this sewing head is more suitable for PVA membrane composite surgical gowns.

[0028] (4) Based on the characteristics of PVA material, the present invention adds an adjustable humidity anilox roller humidification device before sewing. Moreover, whether it is the welding head or the anilox roller humidification device, the range of ultrasonic sewing processes is wider and less restricted by ultrasonic sewing machines. It can be installed and used on more types of ultrasonic sewing machines.

[0029] (5) Surgical gowns made by ultrasonic sewing of membrane fabric composite materials using the ultrasonic sewing process parameters adapted to PVA composite fabrics of the present invention have better liquid barrier and microbial barrier properties. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a flowchart of a high-barrier ultrasonic sewing method for a membrane-fabric composite surgical gown according to the present invention; Figure 2 This is a schematic diagram of the structure of the anilox roller humidification device of the present invention; Figure 3 This is a schematic diagram of the present invention during the humidification and ultrasonic sewing of PVA nonwoven fabric; Figure 4 This is a schematic diagram of the structure of the ultrasonic sewing welding head of the present invention; In the diagram, 1-water storage chamber, 2-anilox roller body, 3-squeegee assembly, 4-coupling, 5-fixing buckle, 6-PVA composite fabric, 7-ultrasonic sewing machine, 8-welding head, 9-closed pattern, 10-diffusing pattern. Detailed Implementation

[0032] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] This invention relates to a high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns, such as... Figure 1 As shown, the steps are as follows: S1 uses a PVA composite fabric made of PVA nonwoven fabric and PVA film.

[0034] PVA (polyvinyl alcohol) nonwoven fabric is selected as the core material for the membrane-fabric composite surgical gown. The composite structure is a full PVA composite system of "PVA nonwoven fabric + PVA film," ensuring the fabric's environmental friendliness, breathability, and barrier properties. The PVA nonwoven fabric has a basis weight of 25-70 g / m², guaranteeing softness and mechanical strength; the PVA film has a thickness of 0.01-0.06 mm and is prepared using a casting process, ensuring molecular chain density and barrier properties.

[0035] S2, an adjustable humidity anilox roller humidification device is connected in series in front of the ultrasonic sewing welding head. The anilox roller humidification device humidifies the PVA nonwoven fabric in the PVA composite fabric. The humidity of the PVA nonwoven fabric is adjusted by changing the surface roughness of the anilox roller, thereby controlling the water content of the PVA nonwoven fabric.

[0036] An adjustable humidity mesh roller humidification device is connected in series in front of the ultrasonic sewing die head as the core pretreatment step before sewing PVA composite fabric, which fundamentally solves the problem of PVA's difficulty in melting.

[0037] like Figure 2 As shown, the anilox roller humidification device consists of a water storage chamber 1, an anilox roller body 2, and a scraper assembly 3 (i.e., a scraper). The anilox roller body 2 is mounted on top of the water storage chamber 1 via a coupling 4 and a fixing buckle 5. The water storage chamber 1 contains deionized water, and the lower half of the anilox roller body 2 is immersed in the deionized water. The anilox roller body 2 is connected to a drive motor via the coupling 4. Figure 3As shown, when the anilox roller humidification device is in use, the drive motor drives the anilox roller body to rotate, and the PVA composite fabric 6 directly covers the upper half of the anilox roller body. The rotation of the anilox roller body humidifies the PVA nonwoven fabric. The squeegee assembly is attached to the surface of the anilox roller body to remove excess water from the surface of the anilox roller body, ensuring the uniformity of liquid carrying volume in the mesh on the surface of the anilox roller body. The humidified PVA nonwoven fabric is sent to the welding head of the ultrasonic sewing machine 7.

[0038] The water content of PVA nonwoven fabric is preferably controlled at 5-20% by the anilox roller humidification device (matching PVA nonwoven fabric with a basis weight of 25-70 g / m²).

[0039] The moisture content of PVA nonwoven fabric is controlled by adjusting the surface roughness of the anilox roller. This is achieved using the following technical means: the anilox roller body is made of 304 stainless steel, and the surface is laser-engraved to form uniformly distributed micron-level mesh holes with a mesh count range of 160-260 mesh, a mesh depth of 0.3-0.5 mm, and a mesh density of 200-300 holes / cm².

[0040] While adjusting the humidity of PVA nonwoven fabric by changing the surface roughness of the anilox roller, the amount of liquid applied is controlled by adjusting the difference between the rotation speed of the anilox roller body and the linear speed of the fabric, thereby assisting in the adjustment of the humidity of PVA nonwoven fabric.

[0041] S3. Use an ultrasonic sewing head to perform ultrasonic sewing on the humidified PVA composite fabric. Adopt ultrasonic sewing process parameters adapted to the PVA composite fabric to obtain a membrane-fabric composite surgical gown.

[0042] Furthermore, an ultrasonic sewing head combining sparse and closed patterns is used, with the pattern design depth adapted to the deformation characteristics and barrier requirements of PVA fibers after humidification, and the closed pattern is located on the outside of the sparse pattern.

[0043] As a specific implementation, the closed-type pattern 9 is the main barrier band: a raised solid annular band that replaces the existing serrated closed pattern, avoiding local stress concentration and heat accumulation caused by sharp turning points, and ensuring that the joint forms a complete and continuous barrier; the dredging-type pattern 10 is the auxiliary connecting band: a raised flow-guiding pattern formed by multiple rhombuses connected end to end; the auxiliary connecting band is parallel to the main barrier band, such as... Figure 4 As shown. The function of the flow-guiding pattern is twofold: first, to disperse ultrasonic energy and prevent excessive local temperature from causing carbonization of PVA fibers; second, through the compression effect of the flow-guiding pattern, to further promote the plastic deformation and interweaving of PVA fibers after humidification, thereby improving the overall bonding strength of the joint.

[0044] In one specific implementation, the width of the sparse pattern is greater than the width of the closed pattern, the width of the closed pattern is ≥1mm (preferably 1-2mm), and the width of the sparse pattern is ≥2mm (2-4mm).

[0045] For PVA composite fabrics after humidification, a range of specific process parameters was obtained through extensive experimentation and optimization, ensuring seam strength and barrier properties while avoiding heat damage. Vibration frequency: 15kHz-30kHz (lower than the sewing frequency of traditional thermoplastic materials, reducing heat accumulation caused by vibration and lowering the risk of PVA fiber carbonization). Sewing pressure: 0.3MPa-0.6MPa (higher than traditional parameters, providing sufficient pressure for the plastic deformation and molecular chain entanglement of PVA fibers after humidification, enhancing bonding force); Sewing speed: 2.5mm / s-5mm / s (Lowering the sewing speed ensures sufficient interweaving and hydrogen bond formation between fibers, avoiding seam breakage due to insufficient bonding); Energy density: 1.2J / mm²-1.8J / mm² (adapted to the energy absorption characteristics of PVA after humidification, ensuring that the energy meets the binding requirements without generating excessive heat). Sewing method: planar overlapping welding, with an alignment error of ≤0.5mm between the upper and lower fabric layers, ultimately forming a closed structure to ensure barrier properties without any gaps.

[0046] In the following examples, the basic ultrasonic sewing machine used is the KS-82 from Shanghai Jinghua Ultrasonic Co., Ltd.

[0047] Example 1: Preparation and Performance Testing of Surgical Gown Sewing Samples (1) 30g / m² PVA nonwoven fabric and 0.02mm thick PVA film were selected as the membrane material for the composite surgical gown.

[0048] (2) The mesh depth of the anilox roller is 0.3 mm and the mesh arrangement density is 280 meshes / cm². By adjusting the mesh number of the anilox roller surface to 240 mesh, 200 mesh and 180 mesh, PVA composite fabric samples B, C and D with water contents of 5%, 10% and 15% are obtained respectively. A control group sample A (water content 0%) without humidification and sample E (water content 10%) with humidification but without using the special welding head of the present invention for sewing are also set up.

[0049] (3) Take a PVA composite fabric sample and place it between the welding head and the sewing platform of the ultrasonic sewing machine. Set the ultrasonic sewing vibration frequency to 20kHz; the ultrasonic sewing pressure to 0.4MPa; the ultrasonic sewing speed to 4.0mm / s; and the ultrasonic sewing energy density to 1.5J / mm². 2 .

[0050] (4) Using the hybrid special welding head of the present invention to sew, surgical gown sample A (0% water content), sample B (5% water content), sample C (10% water content) and surgical gown sample D (15% water content) are obtained; using the traditional hybrid sewing welding head - three virtual and one solid to sew, surgical gown sample E (10% water content) is obtained.

[0051] (5) The sewing areas of surgical gowns A, B, C, D and E were subjected to AATCC127 hydrostatic pressure test, ASTM F1670 blood penetration test and ASTM F1671Φ-X174 phage penetration rate test respectively. The test results are shown in Table 1.

[0052] Table 1 shows the test data of five PVA membrane composite surgical gown samples. According to the test results, the change in water content will greatly affect the liquid barrier performance and microbial barrier performance of the surgical gown seams.

[0053] Table 1 Sewing performance of different ultrasonic sewing patterns

[0054] Example 2: Preparation and Performance Testing of Surgical Gown Sewing Samples (1) 45g / m² PVA nonwoven fabric and 0.04mm thick PVA film were selected as the membrane material for the composite surgical gown.

[0055] (2) The mesh depth of the anilox roller is 0.4 mm and the mesh arrangement density is 260 meshes / cm². By adjusting the mesh aperture of the anilox roller surface to 260 mesh, 220 mesh and 200 mesh, PVA composite fabric samples G, H and I with water contents of 5%, 10% and 15% are obtained respectively. A control group sample F (water content 0%) without humidification and sample J (water content 10%) with humidification but without using the special welding head made in this invention for sewing are also set up.

[0056] (3) Take a PVA composite fabric sample and place it between the welding head and the sewing platform of the ultrasonic sewing machine. Set the ultrasonic sewing vibration frequency to 20kHz; the ultrasonic sewing pressure to 0.5MPa; the ultrasonic sewing speed to 3.5mm / s; and the ultrasonic sewing energy density to 1.6J / mm². 2 .

[0057] (4) Using the special welding head of the present invention, surgical gown sample F (0% water content), sample G (5% water content), sample H (10% water content) and surgical gown sample I (15% water content) are obtained by sewing; using the conventional sparse sewing welding head - honeycomb grid for sewing, surgical gown sample J (10% water content) is obtained.

[0058] (5) The sewing areas of surgical gowns F, G, H, I and J were subjected to AATCC127 hydrostatic pressure test, ASTM F1670 blood penetration test and ASTM F1671Φ-X174 phage penetration rate test respectively. The test results are shown in Table 2.

[0059] Table 2 shows the test data of five PVA membrane composite surgical gown samples. According to the test results, the change in water content will greatly affect the liquid barrier performance and microbial barrier performance of the surgical gown seams.

[0060] Table 2 Sewing performance of different ultrasonic sewing patterns

[0061] Example 3: Preparation and Performance Testing of Surgical Gown Sewing Samples (1) PVA nonwoven fabric with a weight of 50g / m² and PVA film with a thickness of 0.06mm were selected as the membrane material for the composite surgical gown.

[0062] (2) The mesh depth of the anilox roller is 0.4 mm and the mesh arrangement density is 240 meshes / cm². The squeegee pressure is 0.1 MPa. By adjusting the mesh size of the anilox roller surface to 200 mesh, 180 mesh and 160 mesh, PVA composite fabric samples L, M and N with water contents of 10%, 15% and 20% are obtained respectively. A control group sample K (water content 0%) without humidification is set up. A sample O (water content 15%) is humidified but not sewn with the special welding head made in this invention.

[0063] (3) Take a PVA composite fabric sample and place it between the welding head and the sewing platform of the ultrasonic sewing machine. Set the ultrasonic sewing vibration frequency to 15kHz; the ultrasonic sewing pressure to 0.4MPa; the ultrasonic sewing speed to 2.5mm / s; and the ultrasonic sewing energy density to 1.7J / mm². 2 .

[0064] (4) Surgical gown samples K (0% water content), L (10% water content), M (15% water content), and N (20% water content) were obtained by sewing with the special welding head of the present invention. Surgical gown sample O (15% water content) was obtained by sewing with a conventional closed-type sewing welding head with double solid thread.

[0065] (5) The AATCC127 hydrostatic pressure test, ASTM F1670 blood penetration test and ASTM F1671Φ-X174 phage penetration rate test were performed on the seams of surgical gowns K, L, M, L and O respectively. The test results are shown in Table 3.

[0066] Table 3 shows the test data of five PVA membrane composite surgical gown samples. According to the test results, the change in water content will greatly affect the liquid barrier performance and microbial barrier performance of the surgical gown seams.

[0067] Table 3 Sewing performance of different ultrasonic sewing patterns

[0068] Example 4: Preparation and Performance Testing of Surgical Gown Sewing Samples (1) 60g / m² PVA nonwoven fabric and 0.05mm thick PVA film were selected as the membrane material of the composite surgical gown.

[0069] (2) The mesh depth of the anilox roller is 0.5 mm and the mesh arrangement density is 200 meshes / cm². The squeegee pressure is 0.05 MPa. By adjusting the mesh aperture of the anilox roller surface to 200 mesh, 170 mesh and 150 mesh, PVA composite fabric samples Q, R and S with water contents of 10%, 15% and 20% are obtained respectively. A control group sample P (water content 0%) without humidification is set up. A sample T (water content 15%) is humidified but not sewn with the special welding head made in this invention.

[0070] (3) Take a PVA composite fabric sample and place it between the welding head and the sewing platform of the ultrasonic sewing machine. Set the ultrasonic sewing vibration frequency to 30kHz; the ultrasonic sewing pressure to 0.6MPa; the ultrasonic sewing speed to 2.5mm / s; and the ultrasonic sewing energy density to 1.6J / mm². 2 .

[0071] (4) Surgical gown samples P (0% water content), QQ (10% water content), R (15% water content), and S (20% water content) were obtained by sewing with a special welding head. Surgical gown sample T (15% water content) was obtained by sewing with a traditional hybrid sewing welding head—a honeycomb grid with a solid thread.

[0072] (5) The AATCC127 hydrostatic pressure test, ASTM F1670 blood penetration test and ASTM F1671Φ-X174 phage penetration rate test were performed on the sewing areas of surgical gowns P, Q, R, S and T respectively. The test results are shown in Table 4.

[0073] Table 4 shows the test data of five PVA membrane composite surgical gown samples. According to the test results, the change in water content will greatly affect the liquid barrier performance and microbial barrier performance of the surgical gown seams.

[0074] Table 4 Sewing performance of different ultrasonic sewing patterns

[0075] The method of this invention has been promoted and tested in actual production, with more than 500 batches of samples tested. The results of the small-scale test of this method are consistent with normal production conditions.

[0076] 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, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0077] This specification and accompanying drawings are merely illustrative examples of the present invention and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of the present invention. Clearly, those skilled in the art can make various alterations and modifications to the present invention without departing from its scope. Therefore, if such modifications and variations fall within the scope of the present invention and its equivalents, the present invention intends to include these modifications and variations.

Claims

1. A high-barrier ultrasonic sewing method for a membrane-fabric composite surgical gown, characterized in that, include: S1 uses a PVA composite fabric made of PVA nonwoven fabric and PVA film. S2, An adjustable humidity anilox roller humidification device is connected in series in front of the ultrasonic sewing welding head. The anilox roller humidification device humidifies the PVA nonwoven fabric in the PVA composite fabric. The humidity of the PVA nonwoven fabric is adjusted by changing the surface roughness of the anilox roller, thereby controlling the water content of the PVA nonwoven fabric. S3. Use an ultrasonic sewing head to perform ultrasonic sewing on the humidified PVA composite fabric. Adopt ultrasonic sewing process parameters adapted to the PVA composite fabric to obtain a membrane-fabric composite surgical gown.

2. The high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns according to claim 1, characterized in that, The water content of PVA nonwoven fabric is controlled between 1-30% by a humidification device using an anilox roller.

3. The high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns according to claim 1, characterized in that, In the PVA composite fabric, the PVA nonwoven fabric has a basis weight of 25-70 g / m², the PVA film has a thickness of 0.01-0.06 mm, and it is prepared by casting process; the water content of the PVA nonwoven fabric is controlled at 5-20% by a gravure roller humidification device.

4. The high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns according to claim 1, characterized in that, The aforementioned anilox roller humidification device includes a water storage chamber, an anilox roller body, and a scraper assembly; The anilox roller body is installed on top of the water storage chamber, which contains deionized water. The lower half of the anilox roller body is immersed in the deionized water. The anilox roller body is connected to the drive motor via a coupling, and the drive motor drives the anilox roller body to rotate. The PVA composite fabric directly covers the upper half of the anilox roller body, and the rotation of the anilox roller body humidifies the PVA nonwoven fabric. The squeegee assembly is attached to the surface of the anilox roller body and is used to scrape off excess water from the surface of the anilox roller body to ensure the uniformity of liquid carrying volume in the mesh on the surface of the anilox roller body.

5. The high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns according to claim 4, characterized in that, The anilox roller body is made of stainless steel, and the surface is laser-engraved to form uniformly distributed micron-level mesh holes with a mesh count of 160-260 mesh, a mesh depth of 0.3-0.5 mm, and a mesh density of 200-300 holes / cm².

6. The high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns according to claim 4, characterized in that, While adjusting the humidity of PVA nonwoven fabric by changing the surface roughness of the anilox roller, the amount of liquid applied is controlled by adjusting the difference between the rotation speed of the anilox roller body and the linear speed of the fabric, thereby assisting in the adjustment of the humidity of PVA nonwoven fabric.

7. The high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns according to claim 1, characterized in that, An ultrasonic sewing head that combines sparse and closed patterns is used. The pattern design depth is adapted to the deformation characteristics and barrier requirements of PVA fibers after humidification. The closed pattern is located on the outside of the sparse pattern.

8. The high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns according to claim 7, characterized in that, The closed-type pattern is the main barrier band: a solid ring band with a raised shape; the dredging-type pattern is the auxiliary connecting band: a ring of outwardly raised flow-guiding patterns formed by connecting multiple rhombuses end to end; the auxiliary connecting band is parallel to the main barrier band.

9. The high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns according to claim 8, characterized in that, The width of the openwork pattern is greater than the width of the closed pattern. The width of the closed pattern is ≥1mm, and the width of the openwork pattern is ≥2mm.

10. The high-barrier ultrasonic sewing method for membrane-fabric composite surgical gowns according to claim 1, characterized in that, The ultrasonic sewing process parameters for PVA composite fabrics are as follows: Vibration frequency: 15kHz-30kHz; sewing pressure: 0.3MPa-0.6MPa; sewing speed: 2.5mm / s-5mm / s; energy density: 1.2J / mm²-1.8J / mm²; sewing method: planar overlapping welding, with alignment error of upper and lower fabric layers ≤0.5mm, ultimately forming a closed structure.

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