Permeation resistant wet composite outer layer seam sewing method for firefighter protective garments

Abstract

The application discloses a kind of anti-permeation wet composite outer layer joint sewing and attaching method for firefighter protective clothing, belongs to the field of firefighter protective equipment, and the firefighter protective clothing includes coat and trousers, and the sewing and attaching steps of composite outer layer joint inside coat and trousers are as follows: the two pieces of composite outer layer at joint are respectively folded up to a section of interface; the overlock machine is sewn on the interface of the two pieces of composite outer layer with a hem line; the clip burying vehicle is respectively sewn with a chain line on the lower side of hem line; the interface of hem line and two chain lines completed with one side composite outer layer is folded and contacted with composite outer layer; on the interface of hem line and two chain lines after folding and the two sides of composite outer layer, a strip of adhesive tape is attached by heat sealing machine. The method can realize the anti-permeation of composite outer layer joint part, that is, the static water pressure resistance, realize excellent moisture permeability, realize excellent breaking strength, and further help to integrate waterproof and breathable functions into the outer layer to realize the weight reduction and efficiency improvement of new equipment.

Description

Technical Field

[0001] This invention application relates to a method for sewing and bonding the seams of an impermeable and moisture-permeable composite outer layer for firefighter protective clothing. It belongs to the field of firefighter protective equipment and can be used for sewing the seams of the outer layer of equipment such as firefighter firefighting protective clothing (industry standard XF10-2014) and firefighter rescue protective clothing (industry standard XF633-2006 winter style) to achieve its impermeability and moisture-permeability. At the same time, it can also provide technical reference for the design and processing of other special equipment that requires impermeability and moisture-permeability, such as water rescue clothing, ice rescue clothing, and outdoor mountaineering clothing. Background Technology

[0002] Firefighting equipment and special equipment often have requirements for impermeability and moisture permeability, which are mainly achieved through waterproof and breathable layers or coated fabrics. "Impermeability" mainly refers to the hydrostatic pressure resistance of the sample in the national standard GB / T4744-2013 "Test and Evaluation of Waterproof Performance of Textiles - Hydrostatic Pressure Method", i.e., the water impermeability. "Moisture permeability" mainly refers to the moisture permeability of the sample in the national standard GB / T12704.1-2009 "Textiles - Test Method for Moisture Permeability of Fabrics - Part 1: Moisture Absorption Method". Taking firefighter protective clothing as an example, firefighter protective clothing is mainly composed of four layers: an outer layer, a waterproof and breathable layer, a heat insulation layer, and a comfort layer. The waterproof and breathable layer is usually a membrane-coated non-woven spunlace felt or a membrane-coated thin woven fabric. It achieves water resistance and moisture permeability through the bonding of a polytetrafluoroethylene membrane with micron-sized pores. Specifically, "water resistance" means that "the hydrostatic pressure resistance of the waterproof and breathable layer material after 25 washes should not be less than 50 kPa", and "moisture permeability" means that "the moisture permeability of the waterproof and breathable layer material should not be less than 5000 g / (m²•24h)". In addition, in the actual batch testing of finished firefighter protective clothing, the seams of the waterproof and breathable layer also need to be tested for "water resistance".

[0003] To reduce weight and increase efficiency, firefighter protective suits can be optimized from the traditional four-layer structure to a three-layer or even two-layer structure. However, the "waterproofing" and "breathability" functions of the equipment are still achieved by the waterproof and breathable layers of coated nonwoven spunlace felt or coated thin woven fabric. For traditional four-layer firefighter protective suits, the outer layer is usually a thick woven fabric, the waterproof and breathable layer is usually coated spunlace felt nonwoven fabric, the heat insulation layer is usually coated spunlace felt nonwoven fabric, and the comfort layer is usually a thin woven fabric. Its "waterproofing" is mainly achieved by the waterproof and breathable layer of coated nonwoven fabric, while the "waterproofing" at the seams is achieved by applying "adhesive strips consisting of a polyurethane barrier layer and a polyurethane hot melt adhesive layer" to the seams of the coated nonwoven fabric.

[0004] To further reduce weight and increase efficiency, the traditional four-layer structure has gradually evolved into a three-layer or even two-layer structure in recent years. For three-layer firefighter suits, the outer layer is typically a thick woven fabric, the waterproof, breathable, and insulating layer is still a spunlace felt nonwoven fabric membrane, and the comfort layer is usually a thin woven fabric. The overall "waterproofing" of the equipment is still achieved by the waterproof and breathable membrane nonwoven fabric layer, while the "waterproofing" at the seams is achieved by applying a strip consisting of a polyurethane barrier layer and a polyurethane hot melt adhesive layer to the seams of the membrane nonwoven fabric. Similarly, for two-layer firefighter protective suits, the outer layer is often a thick woven fabric, and the waterproof, breathable, insulating, and comfort layer is a thin membrane woven fabric. The overall "waterproofing" of the equipment is still achieved by the waterproof and breathable membrane woven fabric layer, while the "waterproofing" at the seams is achieved by applying a strip consisting of a polyurethane barrier layer and a polyurethane hot melt adhesive layer to the seams of the membrane thin woven fabric. Therefore, the "waterproof" and "breathable" functions of traditional four-layer firefighter protective clothing or optimized three-layer or even two-layer firefighter protective clothing are still achieved by the waterproof and breathable layer. In addition, the standard type test or batch inspection does not require testing the breathability of the seams. Therefore, the current bonding strips are "adhesive strips composed of polyurethane barrier layer and polyurethane hot melt adhesive layer" with poor breathability.

[0005] Currently, conventional thickened woven fabric outer layers have the problem of water seepage and increased weight. Additionally, water can remain between the outer layer and the waterproof and breathable layer, posing a risk of high-temperature vaporization and burns to firefighters. Whether it's four-layer, three-layer, or even two-layer firefighting protective clothing, the conventional thickened woven fabric outer layer is not truly "waterproof," allowing water to easily penetrate to the inside of the outer layer. The inner waterproof and breathable layer, made of coated spunlace nonwoven fabric or thin woven fabric, can prevent further water penetration, but water can still seep through the outer layer or remain between the outer layer and the waterproof and breathable layer at the seams. This water accumulation increases the weight on firefighters, and when the ambient temperature in a fire exceeds 100°C, the trapped water will vaporize. If the water vapor cannot completely escape from the thickened outer woven fabric, there is a risk of steam burns to firefighters. Although the thickened outer woven fabric achieves both "waterproof" and "moisture-permeable" functions in the fabric area after being coated on the inner surface, its seams are not "waterproof". At the same time, the traditional "adhesive strip composed of a polyurethane barrier layer and a polyurethane hot melt adhesive layer" can soften at high temperatures to fix the polyurethane barrier layer to the target object, but the polyurethane barrier layer is difficult to stretch to form micropores.

[0006] Researchers have proposed a patent application, "202210619337.5: A Double-Layer Membrane Firefighter Protective Suit." This patent achieves dual "waterproofing" by covering both the inner and outer surfaces of the outer layer with a membrane, as well as the waterproof and breathable layer. While the outer membrane itself meets the hydrostatic pressure resistance (waterproofing) requirements of the waterproof and breathable layer substrate, if the seams of the outer membrane are made using a flat seam similar to traditional waterproof and breathable layers, and then combined with a "sticker consisting of a polyurethane barrier layer and a polyurethane hot melt adhesive layer," the seams cannot meet the requirement of the industry standard XF10-2014 "Firefighter Protective Suit," which states that "the hydrostatic pressure resistance of the waterproof and breathable layer after 25 washes cannot be less than 50 kPa." Therefore, the "waterproofing" of this patent is still achieved by the second layer of membrane fabric waterproof and breathable material. The main reason for this is that, compared with the soft substrate of the spunlace felt or the thin woven fabric of the waterproof and breathable layer, the outer thick woven fabric is thicker and harder, making it difficult to achieve a tight bond and "waterproofing" through traditional methods, especially the traditional adhesive strip composed of a polyurethane barrier layer and a polyurethane hot melt adhesive layer.

[0007] In addition, researchers have proposed a method for preparing basalt fiber protective clothing for complex environments (patent number 202210469599.8). This patent application achieves high water resistance in the fabric layer by bonding a surface layer and an inner layer with a middle layer using hot melt adhesive and hot pressing, while also exhibiting low heat shrinkage and high thermal protection performance. However, the water resistance at the seams is not demonstrated, especially since the "surface layer" corresponding to the outer layer is not water-resistant, thus failing to solve the problem of water seepage in the outer or surface layer. Furthermore, researchers have proposed a method for manufacturing waterproof clothing (patent number 201010214053.5), proposing a highly waterproof layer made of polyurethane films such as TPE, TPEE, PES, and PET. However, this method does not mention the "water-resistant" treatment method at the seams, and materials such as TPE are also difficult to meet the high-temperature requirements of fire environments, such as thermal stability at 260℃.

[0008] In summary, the outer layer of existing firefighter protective clothing, such as firefighting protective clothing or winter firefighter rescue protective clothing, has the risk of water seepage leading to increased weight and water vaporization at high temperatures, while also requiring breathability. Summary of the Invention

[0009] To address the issues of increased weight and the risk of water vaporization at high temperatures caused by water seepage at the seams of the outer layer of existing firefighter protective clothing, this invention provides a method for sewing and bonding the seams of an impermeable composite outer layer for firefighter protective clothing. This method achieves impermeability and hydrostatic pressure resistance at the seams of the composite outer layer, while also achieving excellent moisture permeability. This, in turn, helps to reduce the weight and increase efficiency of the new equipment by integrating waterproof and breathable functions into the outer layer.

[0010] The technical solution adopted in this invention is: a method for sewing and bonding the seams of the waterproof composite outer layer for firefighter protective clothing, wherein the firefighter protective clothing includes an upper garment and trousers, and the sewing and bonding steps at the seams of the composite outer layer on the inner surface of the upper garment and trousers are as follows: Step 1: Fold up a section of the mating surface of each of the two composite outer layers at the seam. Step 2: The overlock sewing machine sews an overlock line on the mating surface of the two composite outer layers; Step 3: The sewing machine sews a chain stitch on the top and bottom sides of the lockstitch line; Step 4: Fold the completed edge seam and the two chain seams together to one side of the composite outer layer and fold them into contact with the composite outer layer. Step 5: Apply a strip of adhesive to the folded overlock seam, the mating surface of the two chain seams, and the outer composite layers on both sides using a heat sealing machine.

[0011] The beneficial effects of this invention are as follows: First, for the seam area of ​​the composite outer layer, this invention adopts a method of first locking the edge seam and then locking the chain seam. Compared with the traditional flat seam, the chain seam, due to its chain-like structure, can achieve uniform stress distribution and avoid stress concentration. Each node shares the load, and combined with the locking edge seam, it significantly improves the breaking strength of the seam area. At the same time, different stitch densities are set for the horizontal and three-dimensional parts of the protective clothing, achieving stronger seam breaking strength.

[0012] Secondly, after sewing at the seams, this invention introduces a method of bonding adhesive strips consisting of a polytetrafluoroethylene barrier layer and a polyurethane hot melt adhesive layer, achieving impermeability at the seams of the composite outer layer, thereby avoiding the problems of water seepage and water vaporization; it meets the hydrostatic pressure resistance requirements of the waterproof and breathable layer of firefighters' fire-fighting protective clothing, with the hydrostatic pressure resistance of the fabric and seams reaching 50 kPa after 25 washes, thus achieving comprehensive impermeability, resisting the penetration of external water, and solving the problems of water seepage and water vaporization in the outer layer.

[0013] Third, this method also helps improve the breathability and comfort of firefighters' protective clothing. The adhesive strip undergoes longitudinal stretching pretreatment, which helps form a microporous structure. After heating, the adhesive strip is bonded to the seams, allowing the seams to have a breathability of 5000g / 24h•m, just like the non-seam composite outer layer itself. 2 These capabilities ensure that firefighters' sweat and heat are released, maintaining their comfort in terms of heat and humidity.

[0014] In summary, this method can further enhance the strength of the seams of firefighters' protective clothing, effectively resist external water seepage, solve the problem of water vaporization, and also optimize thermal and humidity comfort and reduce weight and increase efficiency. Thus, it provides a new approach for the optimized design of firefighters' personal protective equipment to reduce weight and increase efficiency.

[0015] This method can also achieve the function of the waterproof and breathable layer in the existing firefighter fire-fighting protective clothing or winter firefighter rescue protective clothing by using a separate outer layer. Therefore, the waterproof and breathable layer can be removed, and the previous outer layer and waterproof and breathable layer can be replaced by an outer layer to achieve the effect of weight reduction and efficiency improvement. Attached Figure Description

[0016] Figure 1 To realize the main view of the firefighter protective clothing top of the present invention; Figure 2 for Figure 1 Rear view of the structure; Figure 3 To realize the main view of the firefighter protective suit pants of the present invention; Figure 4 for Figure 3 Rear view of the structure; Figure 5 For the joint of the present invention Figure 1 Point A Figure 2 Point A Figure 3 Enlarged view of the structure at point A, where the two composite outer layers are folded upwards to form a section of the mating surface; Figure 6 For the joint of the present invention Figure 1 Point A Figure 2 Point A Figure 3 Enlarged view of the structure at point A where a lockstitch is sewn onto the mating surface; Figure 7 For the joint of the present invention Figure 1 Point A Figure 2 Point A Figure 3 Enlarged view of the structure at point A where a chain stitch is sewn on the upper and lower sides of the overlock stitch; Figure 8 For the joint of the present invention Figure 1 Point A Figure 2 Point A Figure 3 Enlarged view of the structure at point A where a strip of adhesive is attached to the chain line, the edge line, and the outer composite layers on both sides of the mating surface; Figure 9 For the joint of the present invention Figure 1 Point B Figure 2 Enlarged view of the structure at the overlapping position of the adhesive strips at point B; Figure 10 A schematic diagram illustrating the structure of the adhesive strip of this invention; Figure 11 A schematic diagram illustrating the structure of the composite outer layer of this invention; Figure 12 This is a schematic diagram illustrating the application of adhesive strips to the composite outer layer using the heat sealing machine of this invention.

[0017] In the diagram: 1. Composite outer layer; 1-1. Butt joint; 1-2. Polyurethane adhesive; 1-3. PTFE direct-permeable membrane; 1-4. Outer woven fabric; 2. Overlocking edge; 3. Chain stitch; 4. Seam; 5. Adhesive strip; 5-1. PTFE barrier layer; 5-2. Polyurethane hot melt adhesive layer; 6. Heat sealing machine; 6-1. Upper pressure roller; 6-2. Lower pressure roller; 6-3. Heat sealing machine nozzle. Detailed Implementation

[0018] like Figures 1 to 4 As shown, the firefighter's protective clothing includes a jacket and trousers. The jacket includes a front body, a back body, a placket, shoulders, a collar, and sleeves. The trousers include a front panel, a back panel, a waistband, and a placket. The composite outer layer 1 is the outermost layer of the fabric used for the front body, back body, placket, shoulders, collar, sleeves, front panel, back panel, waistband, and placket.

[0019] like Figure 11 As shown, the composite outer layer 1 consists of polyurethane adhesive 1-2, a polytetrafluoroethylene (PTFE) direct-permeable membrane 1-3, and an outer woven fabric 1-4. The outer woven fabric 1-4 and the PTFE direct-permeable membrane 1-3 are bonded together by multiple polyurethane adhesive dots 1-2. The outer woven fabric 1-4 can be any of a single-layer, double-layer, triple-layer, or quadruple-layer woven fabric. The polyurethane adhesive 1-2 is distributed in a dotted pattern. This polyurethane adhesive can laminate the microporous PTFE direct-permeable membrane 1-3 onto the outer woven fabric 1-4 substrate. The dotted adhesive can both strongly bond the PTFE direct-permeable membrane, ensuring hydrostatic pressure resistance (i.e., "waterproofing"), and reduce obstruction of the micropores of the PTFE direct-permeable membrane, thereby ensuring moisture permeability (i.e., "moisture permeability"). The outer woven fabric 1-4 can be any of a single-layer, double-layer, triple-layer, or quadruple-layer woven fabric.

[0020] The sewing and bonding method for the waterproof composite outer layer seams of firefighter protective clothing, specifically the sewing and bonding steps at the composite outer layer seams on the inner side of the jacket and trousers, is as follows: Step 1, as follows Figure 5 As shown, the fabric edge surfaces at the seam 4 of the two composite outer layers 1 are folded upwards to form a butt joint 1-1. The width of the butt joint 1-1 is 8-15mm, which ensures sufficient space for subsequent overlocking and chain stitching.

[0021] Step 2, as follows Figure 6 As shown, an overlock sewing machine is used to sew an overlock line 2 at the joint surface 1-1 of the two composite outer layers 1. The overlock line 2 can join the joint surface 1-1 of the two composite outer layers 1 together. At the same time, the certain width of the overlock line can ensure that the joint surface 1-1 is of moderate softness and hardness and will not curl up after folding. This helps to ensure a tight fit and smooth surface in subsequent steps with the adhesive strip 5, and ensures the "anti-seepage" function after washing.

[0022] Step 3, as follows Figure 7 As shown, the clamping machine sews a chain thread 3 on the upper and lower sides of the locking edge line 2. The two chain threads 3 can tightly bond the two composite outer layers 1 together, ensuring the breaking strength of the joint between the two composite outer layers 1. At the same time, it also helps to form a clear fold line with the locking edge line 2, laying the foundation for subsequent bonding with the adhesive strip 5. In particular, this combination of one locking edge line 2 and two chain threads 3 can achieve physical strength while having little impact on the hardness of the mating surface 1-1, thus ensuring the subsequent bonding of the adhesive strip in this area. The locking edge line 2 and the chain threads 3 work together to ensure that the breaking strength of the joint meets the requirement of not less than 650N, thus ensuring the durability of the equipment.

[0023] Step 4: Fold the mating surfaces 1-1 of the completed edge seam 2 and the two chain seams 3 toward a composite outer layer 1 and make them contact the surface of the composite outer layer 1.

[0024] Step 5, as follows Figure 8 As shown, a strip of adhesive is applied to the mating surface 1-1 of the two chain lines 3 and the locking edge line 2 after folding, and to the outer composite layer 1 on both sides using a heat sealing machine 6. The application of the adhesive strip 5 makes the joint area impermeable, and its hydrostatic pressure resistance meets the requirement of not less than 50 kPa. This ensures that the outer layer of the firefighter can effectively resist external water seepage and water retention, ensuring the firefighter's weight reduction and comfort, and avoiding the danger of water vaporization.

[0025] The front and back panels and placket of the jacket, and the front and back panels and placket of the trousers are horizontal parts, and the curvature of these parts is generally less than 10m. -1 The curve is smaller and the radius is larger and more horizontal, so the chain stitch 3 for horizontal parts uses a normal stitch density, that is, no less than 12 stitches within 3cm; the collar, shoulders, sleeves, waistbands and other parts are three-dimensional parts, and the curvature of these parts is generally higher than 10m. -1 With a larger curvature and a smaller radius, it is more three-dimensional. Therefore, the chain thread 3 for the three-dimensional parts adopts a denser stitch density, with no less than 13 stitches within 3cm.

[0026] Chain thread 3 is either double-needle flat stitch or single-needle flat stitch; the specifications of overlock thread 2 and chain thread 3 are 40S / 3, 30S / 3, or 20S / 3.

[0027] Both the overlock stitch 2 and the chain stitch 3 are made from the following raw materials by weight percentage: Meta-aramid staple fiber 0%-100%; Para-aramid staple fiber content ranges from 0% to 80%; Polyimide staple fiber 0%-70%; Flame-retardant conductive fiber 0%-20%.

[0028] like Figure 9 , Figure 10 As shown, during the bonding process of the heat sealing machine 6, a layer of flame-retardant adhesive is applied between the overlapping parts of the adhesive strips 5. The adhesive strip 5 is composed of a polytetrafluoroethylene barrier layer 5-1 coated with a polyurethane hot melt adhesive layer 5-2; the width of the adhesive strip 5 is 16-23mm, which ensures a tight fit at the corresponding joints and thus achieves "waterproofing".

[0029] The overlapping area refers to the area where the armholes of the upper garment and the sleeves intersect. First, the sewing and bonding of the upper body and sleeves are completed. Then, sewing and bonding continue at the armholes. At this point, a diamond-shaped overlap will appear between the horizontal adhesive strips used for sewing and bonding the sleeves, or between the horizontal adhesive strips used for sewing and bonding the upper garment and the adhesive strips used for sewing and bonding the armholes. That is, at the seam 4 between the sleeve and the shoulder, an adhesive strip 5 is applied through steps 1 to 5. After the armhole and upper garment armhole are sewn together in steps 1 to 4, when applying an adhesive strip 5 in step 5, it will overlap with the adhesive strip 5 applied at the previously completed seam between the sleeve and the shoulder through steps 1 to 5. A layer of flame-retardant adhesive is applied between the overlapping parts of the adhesive strips 5 to solve the problem of poor adhesion caused by the hydrophobic and oleophobic polytetrafluoroethylene barrier layer 5-1 of the overlapping parts of the adhesive strips 5 facing outwards. This ensures that the adhesive strips 5 of the overlapping parts can be smoothly attached. The flame-retardant adhesive has an aluminum hydroxide content of not less than 35%, and the amount of flame-retardant adhesive used in each overlapping part is not less than 0.005g.

[0030] The method for heat sealing machine 6 to bond a strip of adhesive 5 is as follows: Figure 12As shown, the adhesive strip 5 is stretched longitudinally, with an elongation rate of 3%-10%. The adhesive strip 5 is then fixed to one side of the upper pressure roller 6-1 of the heat sealer 6, with the polyurethane hot melt adhesive layer 5-2 facing outwards. Hot air from the heat sealer nozzle 6-3 heats the polyurethane hot melt adhesive layer 5-2 on the adhesive strip 5. The mating surfaces 1-1 of the folded chain thread 3 and the locking edge 2, along with the two sides of the composite outer layer 1, are placed on the lower pressure roller 6-2, with the mating surfaces 1-1 of the chain thread 3 and the locking edge 2, and one side of the two sides of the composite outer layer 1, facing outwards. The heated adhesive strip 5, along with the heated adhesive strip 5, extends between the upper pressure roller 6-1 and the lower pressure roller 6-2 of the heat sealer 6. Through the rotation of the upper pressure roller 6-1 and the lower pressure roller 6-2, the heated adhesive strip 5 is bonded to the mating surfaces 1-1 of the folded chain thread 3 and the locking edge 2, and the two sides of the composite outer layer 1. After bonding, the unbonded adhesive strip 5 is cut off by the scissors of the heat sealer 6. The hot air temperature ejected from nozzle 6-3 of the heat sealing machine is 420-580℃, and the pressure of nozzle 6-3 is 0.05-0.08MPa; the pressure between the upper pressure roller 6-1 and the lower pressure roller 6-2 is 0.04-0.35MPa, and the rotation speed of the upper pressure roller 6-1 and the lower pressure roller 6-2 is 5-23m / min.

[0031] The longitudinal stretching of the adhesive strip 5 helps to form breathable and moisture-permeable channels in the PTFE barrier layer 5-1. Then, after heating the polyurethane hot melt adhesive layer 5-2, a tight bond is achieved between the PTFE barrier layer 5-1 and the PTFE barrier layer 5-1 at the joint 4. Simultaneously, the width of the adhesive strip 5 is greater than the width of the mating surface 1-1, the chain line 3, and the lock edge line 2 at the joint 4, further enhancing the tightness of the bond between the adhesive strip 5 and the joint 4. The 3%-10% longitudinal stretching also ensures that the transverse width of the adhesive strip 5 remains unchanged. Furthermore, the bonded adhesive strip 5 after stretching ensures that the moisture permeability at the joint is not less than 5000 g / 24h•m. 2 This capability ensures that the firefighters' sweat is stored and released, maintaining their thermal and humid comfort.

[0032] Example 1, Step 1: Cut the composite outer layer 1 to obtain the corresponding cut pieces, and fold the fabric edge surface of the seam 4 of the two composite outer layers 1 upwards to connect the butt joint surface 1-1. The width of the butt joint surface 1-1 is 11mm.

[0033] Step 2: The overlock machine sews an overlock line 2 on the mating surface 1-1 of the two composite outer layers 1. The overlock line 2 is made of yarn with a specification of 20S / 3, which is a blend of 50% polyimide short fiber, 47% meta-aramid short fiber and 3% flame-retardant conductive fiber. The Z-shaped overlock has a horizontal width of 6mm, a vertical spacing of 3mm, and a distance of 5mm between the center line of the Z-shaped overlock and the edge of the mating surface 1-1.

[0034] Step 3: Using a sewing machine, sew a chain stitch 3 on both the upper and lower sides of the overlock stitch 2. The chain stitch 3 is a double-needle flatbed sewing thread made of a 30S / 3 yarn blended from 60% polyimide short fiber, 20% meta-aramid short fiber, 17% para-aramid short fiber, and 3% flame-retardant conductive fiber. The first chain stitch 3 on the lower side of the overlock stitch 2 is 10mm away from the edge of the mating surface 1-1. Then, sew a second chain stitch 3 on the upper side of the overlock stitch 2. The second double-needle flatbed sewing chain stitch 3 is 9mm away from the first double-needle flatbed sewing chain stitch 3 and 1mm away from the edge of the mating surface 1-1. This design can tightly bond the two composite outer layers 1 together. The chain stitch 3 on the horizontal parts uses a stitch density of 13 stitches per 3cm. The chain stitch 3 on the three-dimensional parts other than the "armhole and upper garment armhole seam" uses a stitch density of 14 stitches per 3cm. The combination of the overlock stitch 2 and the chain stitch 3 ensures that the breaking strength of the seam reaches 1396N, which meets the requirement of not less than 650N as stipulated in the XF10-2014 "Firefighter Firefighting Protective Clothing" standard.

[0035] Step 4: Fold the mating surfaces 1-1 of the completed edge stitch 2 and chain stitch 3 toward a composite outer layer 1 and make them contact the surface of the composite outer layer 1.

[0036] Step 5: A strip of adhesive 5 is applied to the mating surface 1-1 of the folded chain stitch 3 and the overlock stitch 2, and to the outer composite layer 1 on both sides, using a heat-sealing machine 6. The adhesive strip 5, model TY2170, is composed of a polytetrafluoroethylene barrier layer and a polyurethane hot melt adhesive layer, with a width of 20mm and a thickness of 0.8mm. This width ensures a tight fit at the corresponding seams, thus achieving "waterproofing." The adhesive strip 5 enables the seams to resist water seepage, achieving a hydrostatic pressure resistance of 65kPa, meeting the requirement of not less than 50kPa stipulated in the XF20-2014 "Firefighter Protective Clothing" standard.

[0037] In step 5 above, a layer of flame-retardant adhesive is applied between the overlapping parts of the adhesive strips 5 of the sleeve armhole and the upper armhole. The flame-retardant adhesive contains 50% polyurethane prepolymer, 38% aluminum hydroxide flame retardant, 5% phosphorus flame retardant, and 7% plasticizer and dispersant. The amount of flame-retardant adhesive used at each overlapping point is 0.005g. The addition of flame-retardant adhesive to this overlapping part allows the previous adhesive strip 5 to be smoothly adhered to the opposite side of the overlapping position, i.e., the position where the next adhesive strip 5 is adhered to the previous adhesive strip. This solves the problem of difficult adhesion caused by the hydrophobic and oleophobic nature of the polytetrafluoroethylene barrier layer 5-1, making the overlapping position as easy to adhere to the adhesive strip as the mating surfaces 1-1 at both ends and the composite outer layers 1 on both sides.

[0038] The method for applying a strip 5 to the heat sealing machine 6 is as follows: A TY2170 strip 5, consisting of a polytetrafluoroethylene barrier layer and a polyurethane hot melt adhesive layer, is selected. The strip 5 is stretched longitudinally, with an elongation percentage of 4%. The strip 5 is then fixed to one side of the upper pressure roller 6-1 of the heat sealing machine 6, with the polyurethane hot melt adhesive layer 5-2 facing outwards. Hot air from the heat sealing machine nozzle 6-3 heats the polyurethane hot melt adhesive layer 5-2 on the strip 5. The hot air temperature is 480℃, and the pressure of the heat sealing machine nozzle 6-3 is 0.05MPa. The folded chain thread 3 is then... The mating surface 1-1 of the locking edge line 2 and the two sides of the composite outer layer 1 are placed on the lower pressure roller 6-2. At the same time, the mating surface 1-1 of the locking edge line 3 and the two sides of the composite outer layer 1 face outwards, and together with the heated adhesive strip 5, they are inserted between the upper pressure roller 6-1 and the lower pressure roller 6-2 of the heat sealing machine 6. The pressure between the upper pressure roller 6-1 and the lower pressure roller 6-2 is 0.15MPa. By rotating the upper pressure roller 6-1 and the lower pressure roller 6-2, the heated adhesive strip 5 is glued on the mating surface 1-1 of the folded locking edge line 3 and the two sides of the composite outer layer 1. The upper pressure roller 6-1 and the lower pressure roller 6-2 rotate at a speed of 16 m / min. The longitudinal stretching of the adhesive strip 5 helps to form breathable and moisture-permeable channels in the PTFE barrier layer 5-1. Then, after heating the polyurethane hot melt adhesive layer 5-2, a tight bond is achieved between the PTFE barrier layer 5-1 and the PTFE barrier layer 5-1 on the joint 4 or overlapping area, and the adhesive strip 5 is also bonded to it. Simultaneously, the width of the adhesive strip 5 is greater than the width of the mating surface 1-1, the chain line 3, and the locking edge line 2 at the joint 4, further enhancing the tight bond between the adhesive strip 5 and the joint 4. The stretched adhesive strip 5, when bonded, results in a moisture permeability of 6532 g / 24 h•m at the joint. 2 The above capabilities meet the requirements of XF10-2014 "Firefighter Protective Clothing" for a moisture permeability of no less than 5000g / 24h•m for the waterproof and breathable fabric layer. 2 This meets the requirements, thus ensuring the heat from the firefighters' sweat is released and maintaining their thermal and humid comfort. After the bonding is completed, the unbonded adhesive strips 5 are cut off by the scissors of the heat sealing machine 6.

[0039] Finally, for the composite outer layer of the firefighter protective suit formed by the anti-permeability and moisture-proof composite outer layer seam sewing bonding method, the inner surface of the composite outer layer is then sewn together with the edges of the waterproof and breathable layer, the heat insulation layer, and the comfort layer, thus forming a new type of firefighter protective suit.

[0040] Example 2, Step 1: Cut the composite outer layer 1 to obtain the corresponding cut pieces, such as... Figure 5 As shown, the fabric edge surfaces at the seam 4 of the two composite outer layers 1 are folded upwards to form a butt joint 1-1, with the butt joint 1-1 having a width of 13mm.

[0041] Step 2: The overlock machine sews an overlock line 2 on the mating surface 1-1 of the two composite outer layers 1. The overlock line 2 is made of yarn with a specification of 40S / 3, which is a blend of 30% meta-aramid short fiber, 34% para-aramid short fiber, 34% polyimide short fiber, and 2% flame-retardant conductive fiber. The Z-shaped overlock has a horizontal width of 8mm, a vertical spacing of 3mm, and the distance between the center line of the Z-shaped overlock and the edge of the mating surface 1-1 is 6mm. Step 3: A chain stitch 3 is sewn on both the upper and lower sides of the overlock thread 2 using a double-needle flatbed sewing machine. The chain stitch 3 is made of a 40S / 3 yarn blended from 30% meta-aramid short fiber, 34% para-aramid short fiber, 34% polyimide short fiber, and 2% flame-retardant conductive fiber. The first chain stitch 3 on the lower side of the overlock thread 2 is 12mm from the edge of the mating surface 1-1. Then, a second chain stitch 3 is sewn on the upper side of the overlock thread 2. The second chain stitch 3 is 11mm from the first chain stitch 3 and 1mm from the edge of the mating surface 1-1. 3. The second chain stitch 3 is located on both sides of the overlock stitch 2 on the mating surface 1-1. This design can tightly bond the two composite outer layers 1 together. The chain stitch 3 in the horizontal part adopts a stitch density of 12 stitches per 3cm. The chain stitch 3 in the three-dimensional part other than the "armhole and upper armhole seam" adopts a stitch density of 13 stitches per 3cm. The overlock stitch 2 and the chain stitch 3 together make the breaking strength of the seam reach 1276N, which meets the requirement of not less than 650N specified in the XF10-2014 "Firefighter Firefighting Protective Clothing" standard.

[0042] Step 4: Fold the mating surfaces 1-1 of the completed edge stitch 2 and chain stitch 3 toward a composite outer layer 1 and make them contact the surface of the composite outer layer 1.

[0043] Step 5: A strip of adhesive 5 is applied to the mating surface 1-1 of the folded chain stitch 3 and the overlock stitch 2, and to the outer composite layer 1 on both sides, using a heat-sealing machine 6. The adhesive strip 5 is 18mm wide, 0.9mm thick, and of model JCN00021, composed of a polytetrafluoroethylene barrier layer and a polyurethane hot-melt adhesive layer. This width ensures a tight fit at the corresponding seams, thus achieving "waterproofing." The adhesive strip 5 enables the seams to resist water seepage, achieving a hydrostatic pressure resistance of 58kPa, meeting the requirement of not less than 50kPa stipulated in the XF20-2014 "Firefighter Protective Clothing" standard.

[0044] In step 5 above, a layer of flame-retardant adhesive is applied between the overlapping parts of the adhesive strips 5 of the sleeve armhole and the upper armhole. The flame-retardant adhesive contains 55% polyurethane prepolymer, 34% aluminum hydroxide flame retardant, 6% phosphorus flame retardant, and 5% plasticizer and dispersant. The amount of flame-retardant adhesive used at each overlapping point is 0.006g. The addition of flame-retardant adhesive to this overlapping part allows the previous adhesive strip 5 to be smoothly adhered to the opposite side of the overlapping position, i.e., the next adhesive strip 5 is adhered to the position of the previous adhesive strip. This solves the problem of difficult adhesion caused by the hydrophobic and oleophobic nature of the polytetrafluoroethylene barrier layer 5-1, making the overlapping position as easy to adhere to the adhesive strip as the mating surfaces 1-1 at both ends and the composite outer layers 1 on both sides.

[0045] The method for applying a strip 5 to a heat sealer 6 is as follows: Select a strip 5 of model JCN00021, which is composed of a polytetrafluoroethylene barrier layer and a polyurethane hot melt adhesive layer. Stretch the strip 5 longitudinally, with an elongation percentage of 6%. Then fix the strip 5 to one side of the upper pressure roller 6-1 of the heat sealer 6, with the polyurethane hot melt adhesive layer 5-2 facing outwards. The hot air sprayed from the heat sealer nozzle 6-3 heats the polyurethane hot melt adhesive layer 5-2 on the strip 5. The hot air temperature is 500℃, and the pressure of the heat sealer nozzle 6-3 is 0.07MPa. Place the mating surfaces 1-1 of the folded chain thread 3 and the edge locking thread 2, and the two sides of the composite outer layer 1 on the lower pressure roller 6-2, with one side of the mating surfaces 1-1 of the chain thread 3 and the edge locking thread 2 and the two sides of the composite outer layer 1 facing outwards. Together with the heated adhesive strip 5, extend it between the upper pressure roller 6-1 and the lower pressure roller 6-2 of the heat sealing machine 6. The pressure between the upper pressure roller 6-1 and the lower pressure roller 6-2 is 0.2MPa. The rotation of the upper pressure roller 6-1 and the lower pressure roller 6-2 achieves bonding of the heated adhesive strip 5 to the mating surfaces 1-1 of the folded chain line 3 and the locking edge line 2, and to the outer composite layers 1 on both sides. The rotation speed of the upper pressure roller 6-1 and the lower pressure roller 6-2 is 23 m / min. The longitudinal stretching of the adhesive strip 5 helps to form breathable and moisture-permeable channels in the polytetrafluoroethylene barrier layer 5-1. Then, after heating the polyurethane hot melt adhesive layer 5-2, a tight bond is achieved between the polytetrafluoroethylene barrier layer 5-1 and the adhesive strip 5 at the joint 4 or overlapping area. At the same time, the width of the adhesive strip 5 is greater than the width of the mating surfaces 1-1, the chain line 3, and the locking edge line 2 at the joint 4, which helps to improve the tightness of the bonding between the adhesive strip 5 and the joint 4. The above-mentioned stretched adhesive strip 5 bonding results in a moisture permeability of 6467 g / 24h•m at the joint area. 2 The above capabilities meet the requirements of XF10-2014 "Firefighter Protective Clothing" for a moisture permeability of no less than 5000g / 24h•m for the waterproof and breathable fabric layer. 2This meets the requirements, thus ensuring the heat from the firefighters' sweat is released and maintaining their thermal and humid comfort. After the bonding is completed, the unbonded adhesive strips 5 are cut off by the scissors of the heat sealing machine 6.

[0046] Finally, for the composite outer layer of the firefighter protective suit formed by the anti-permeability and moisture-proof composite outer layer seam sewing bonding method, the inner surface of the composite outer layer is then sewn together with the edges of the waterproof and breathable layer, the heat insulation layer, and the comfort layer, thus forming a new type of firefighter protective suit.

[0047] Example 3, Step 1: Cut the composite outer layer 1 to obtain the corresponding cut pieces, and fold the fabric edge surface of the seam 4 of the two composite outer layers 1 upwards to connect the butt joint surface 1-1, the width of the butt joint surface 1-1 is 12mm.

[0048] Step 2: The overlock sewing machine sews an overlock thread 2 on the mating surface 1-1 of the two composite outer layers 1. The overlock thread 2 is a single-needle flatbed sewing thread made of 40% polyimide short fiber, 40% meta-aramid short fiber, 17% para-aramid short fiber, and 3% flame-retardant conductive fiber, with a specification of 40S / 3. The Z-shaped overlock has a Z-shaped horizontal width of 7mm, a Z-shaped vertical spacing of 2.8mm, and a Z-shaped center line distance of 6.5mm from the edge of the mating surface 1-1. The overlock thread 2 can join the mating surfaces 1-1 of the two composite outer layers 1 together.

[0049] Step 3: A chain stitch 3 is sewn on both the upper and lower sides of the overlock stitch 2 using a double-needle flatbed sewing machine. The chain stitch 3 is made of a 40S / 3 yarn blended from 35% polyimide short fiber, 35% meta-aramid short fiber, 27% para-aramid short fiber, and 3% flame-retardant conductive fiber. The first chain stitch 3 on the lower side of the overlock stitch 2 is 11mm from the edge of the mating surface 1-1. Then, a second chain stitch 3 is sewn on the upper side of the overlock stitch 2, 9.5mm from the first chain stitch 3 and from the mating surface. The edge of 1-1 is 1.5mm, which allows the two composite outer layers 1 to be tightly bonded together; the chain stitch 3 on the horizontal part adopts a stitch density of 12 stitches per 3cm, and the chain stitch 3 on the three-dimensional part other than the "armhole and upper armhole seam" adopts a stitch density of 13 stitches per 3cm; the overlock stitch 2 and the chain stitch 3 together make the breaking strength of the seam reach 1204N, which meets the requirement of not less than 650N specified in the XF10-2014 "Firefighter Firefighting Protective Clothing" standard.

[0050] Step 4: Fold the mating surfaces 1-1 of the completed edge stitch 2 and chain stitch 3 toward a composite outer layer 1 and make them contact the surface of the composite outer layer 1.

[0051] Step 5: Apply a strip of adhesive 5 to the mating surface 1-1 of the folded chain stitch 3 and the edge stitch 2 and the outer composite layer 1 on both sides using a heat sealing machine 6. The adhesive strip 5 is 19mm wide, 0.9mm thick, and of model TY2170. It is composed of a polytetrafluoroethylene barrier layer and a polyurethane hot melt adhesive layer. This width ensures a tight fit at the corresponding seam, thus achieving "waterproofing". The adhesive strip 5 enables the seam to resist water seepage, and its hydrostatic pressure resistance reaches 62kPa, which meets the requirement of not less than 50kPa stipulated in the XF20-2014 "Firefighter Firefighting Protective Clothing" standard.

[0052] In step 5 above, a layer of flame-retardant adhesive is applied between the overlapping parts of the adhesive strips 5 of the sleeve armhole and the upper armhole. The flame-retardant adhesive contains 57% polyurethane prepolymer, 35% aluminum hydroxide flame retardant, 5% phosphorus flame retardant, and 3% plasticizer and dispersant. The amount of flame-retardant adhesive used at each overlapping point is 0.006g. The addition of flame-retardant adhesive to this overlapping part allows the previous adhesive strip 5 to be smoothly adhered to the reverse side of the overlapping position, i.e., the position where the next adhesive strip 5 is adhered to the previous adhesive strip. This solves the problem of difficult adhesion caused by the hydrophobic and oleophobic nature of the polytetrafluoroethylene barrier layer 5-1, making the overlapping position as easy to adhere to the adhesive strip as the mating surfaces 1-1 at both ends and the composite outer layers 1 on both sides.

[0053] The method for applying a strip 5 to the heat sealing machine 6 is as follows: A TY2170 strip 5, consisting of a polytetrafluoroethylene barrier layer and a polyurethane hot melt adhesive layer, is selected. The strip 5 is stretched longitudinally, with an elongation percentage of 5%. The strip 5 is then fixed to one side of the upper pressure roller 6-1 of the heat sealing machine 6, with the polyurethane hot melt adhesive layer 5-2 facing outwards. Hot air sprayed from the nozzle 6-3 of the heat sealing machine heats the polyurethane hot melt adhesive layer 5-2 on the strip 5; the hot air temperature is 500°C. At ℃, the pressure of nozzle 6-3 of the heat sealing machine is 0.08MPa; place the mating surfaces 1-1 of the folded chain line 3 and the edge locking line 2 and the two sides of the composite outer layer 1 on the lower pressure roller 6-2, with one side of the mating surfaces 1-1 of the chain line 3 and the edge locking line 2 and the two sides of the composite outer layer 1 facing outwards, and extend them together with the heated adhesive strip 5 into the space between the upper pressure roller 6-1 and the lower pressure roller 6-2 of the heat sealing machine 6, with the pressure between the upper pressure roller 6-1 and the lower pressure roller 6-2 being 0.15MPa; The rotation of the upper pressure roller 6-1 and the lower pressure roller 6-2 achieves bonding of the heated adhesive strip 5 to the mating surfaces 1-1 of the folded chain line 3 and the locking edge line 2, and to the outer composite layers 1 on both sides. The rotation speed of the upper pressure roller 6-1 and the lower pressure roller 6-2 is 17 m / min. The longitudinal stretching of the adhesive strip 5 helps to form breathable and moisture-permeable channels in the polytetrafluoroethylene barrier layer 5-1. Then, after heating the polyurethane hot melt adhesive layer 5-2, the polytetrafluoroethylene barrier layer 5-1 and the polytetrafluoroethylene barrier layer 5-1 of the adhesive strip 5 at the joint 4 or overlapping part are tightly bonded. At the same time, the width of the adhesive strip 5 is greater than the width of the mating surfaces 1-1, the chain line 3, and the locking edge line 2 at the joint 4, which helps to improve the tightness of the bonding between the adhesive strip 5 and the joint 4. The above-mentioned stretched adhesive strip 5 bonding results in a moisture permeability of 6451 g / 24 h•m at the joint. 2 The above capabilities meet the requirements of XF10-2014 "Firefighter Protective Clothing" for a moisture permeability of no less than 5000g / 24h•m for the waterproof and breathable fabric layer. 2 This meets the requirements, thus ensuring the heat from the firefighters' sweat is released and maintaining their thermal and humid comfort. After the bonding is completed, the unbonded adhesive strips 5 are cut off by the scissors of the heat sealing machine 6.

[0054] Finally, for the composite outer layer of the firefighter protective suit formed by the anti-permeability moisture composite outer layer seam sewing bonding method, the inner surface of the composite outer layer is sewn to the edge of the heat insulation layer and the comfort layer, and finally a new type of firefighter protective suit is formed.

[0055] In summary, Examples 1, 2, and 3 in the implementation examples all meet the standard requirement of impermeability of not less than 50 kPa, i.e., hydrostatic pressure resistance, while the old method cannot meet this requirement; Examples 1, 2, and 3 in the implementation examples all meet and far exceed the standard requirement of not less than 5000 g / 24h·m 2 The expected moisture permeability performance requirement is met by the old method, which barely meets the requirement and is at risk of failing. In addition, the tensile strength of Examples 1, 2 and 3 in the implementation examples can meet the requirement of not less than 650N, while the old method, although it also meets the requirement, has a lower value.

Claims

1. A method for sewing and bonding the seams of a moisture-resistant composite outer layer for firefighter protective clothing, the firefighter protective clothing comprising an upper garment and trousers, characterized in that, The sewing and bonding steps at the seam of the composite outer layer inside the top and pants are as follows: Step 1: Fold up a section of the mating surface (1-1) of the two composite outer layers (1) at the seam (4). Step 2: The overlock machine sews an overlock line (2) on the mating surface (1-1) of the two composite outer layers (1). Step 3: The sewing machine sews a chain thread (3) on the upper and lower sides of the lock edge line (2). Step 4: Fold the mating surfaces (1-1) of the completed edge-locking line (2) and the two chain lines (3) to one side of the composite outer layer (1) to make contact with the composite outer layer (1); Step 5: Apply a strip of adhesive to the mating surface (1-1) of the folded overlocking line (2), the two chain lines (3) and the two sides of the composite outer layer (1) by using a heat sealing machine (6). The adhesive strip (5) is composed of a polytetrafluoroethylene barrier layer (5-1) coated with a polyurethane hot melt adhesive layer (5-2); The method of bonding a strip of adhesive using a heat sealer is as follows: stretch the strip (5) longitudinally, with an elongation percentage of 3%-10%, and then fix the strip (5) on one side of the upper pressure roller (6-1) of the heat sealer (6), with the polyurethane hot melt adhesive layer (5-2) facing outward. The hot air sprayed from the nozzle (6-3) of the heat sealing machine heats the polyurethane hot melt adhesive layer (5-2) on the adhesive strip (5); Insert the folded chain thread (3), the locking edge thread (2) mating surface (1-1) and the two sides of the composite outer layer (1), along with the heated adhesive strip (5), into the space between the upper pressure roller (6-1) and the lower pressure roller (6-2) of the heat sealing machine (6); By rotating the upper pressure roller (6-1) and the lower pressure roller (6-2), the heated adhesive strip (5) is bonded to the mating surface (1-1) of the folded chain line (3), the locking edge line (2) and the two sides of the composite outer layer (1). After the gluing is completed, the unglued adhesive strips (5) are cut off by the scissors of the heat sealer (6). The hot air temperature ejected from the heat sealing machine nozzle (6-3) is 420-580℃, and the pressure of the heat sealing machine nozzle (6-3) is 0.05-0.08MPa; The pressure between the upper pressure roller (6-1) and the lower pressure roller (6-2) is 0.04-0.35MPa, and the rotational speed of the upper pressure roller (6-1) and the lower pressure roller (6-2) is 5-23 r / min.

2. The method for sewing and bonding the seams of the waterproof composite outer layer for firefighter protective clothing according to claim 1, characterized in that, During the process of the heat sealing machine (6) bonding a strip of adhesive (5), a layer of flame-retardant adhesive is applied between the overlapping parts of the adhesive strip (5).

3. The method for sewing and bonding the seams of the waterproof composite outer layer for firefighter protective clothing according to claim 1, characterized in that, The width of the mating surface (1-1) is 8-15mm.

4. The method for sewing and bonding the seams of the waterproof composite outer layer for firefighter protective clothing according to claim 1, characterized in that, The width of the adhesive strip (5) is 16-23mm.

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