Fabric membrane and use thereof

Abstract

The application discloses a fabric diaphragm and application thereof, wherein the thickness of the fabric diaphragm is 0.4-3.0 mm, the ratio of the unfolded area to the actual area of the fabric diaphragm is less than 1.4, and the number of hairiness on the surface of the fabric diaphragm within 1 cm is less than 10. The fabric diaphragm has the characteristics of high air tightness and high durability.

Description

Technical Field

[0001] This invention relates to a fabric diaphragm and its uses. Background Technology

[0002] The electrolyzer is the main core material of alkaline water electrolysis hydrogen production equipment, and the diaphragm is an essential component of the electrolyzer. The diaphragm is located between the anode and cathode of the electrolyzer, preventing the hydrogen produced at the cathode from mixing with the oxygen produced at the anode, while ensuring that ions can quickly pass through the diaphragm, thereby improving electrolysis efficiency.

[0003] Because the diaphragm is used in a high-pressure, high-temperature alkaline environment, its thickness is typically above 0.4mm to withstand external forces during installation and adapt to harsh operating conditions. However, to obtain a thicker diaphragm, finer yarns with higher curvature must be used. This results in a large ratio between the unfolded area and the actual area of ​​the diaphragm, leading to high resistance, low airtightness, high power consumption during operation, and low hydrogen purity. Furthermore, a large amount of fuzz inevitably forms on the diaphragm surface during weaving and other processing. When the diaphragm is placed in the electrolytic cell, the continuous flow of alkaline solution causes this fuzz to detach from the diaphragm, loosening the yarn and reducing the diaphragm's density and abrasion resistance.

[0004] For example, Chinese patent CN104746202A discloses a diaphragm cloth for a water electrolyzer and its production method. Because this diaphragm cloth is not post-processed, the ratio of its unfolded area to its actual area is large, the yarn is highly curved, and the resulting diaphragm cloth is thick, leading to high resistance and low airtightness. Furthermore, since this diaphragm cloth is made of polyphenylene sulfide fiber yarn, its surface has a large amount of fuzz. After installation and use, the diaphragm becomes loose as the fuzz falls off, easily forming large pores, reducing the airtightness of the diaphragm and affecting its durability. Summary of the Invention

[0005] The purpose of this invention is to provide a fabric diaphragm with high airtightness and high durability.

[0006] The technical solution of the present invention is as follows: the thickness of the fabric diaphragm of the present invention is 0.40 to 3.00 mm, and the ratio of the unfolded area of ​​the fabric diaphragm to the actual area is less than 1.40, and the number of hairs on the surface of the fabric diaphragm within 1 cm is less than 10.

[0007] The beneficial effects of the present invention are: the fabric diaphragm of the present invention has the characteristics of high airtightness and high durability. Attached Figure Description

[0008] Figure 1This is a schematic diagram of the cross-sectional structure of the fabric diaphragm of the present invention. In the figure, A is the weft yarn, B is the warp yarn, S1 is the unfolded area (surface area) of the fabric diaphragm, and S2 is the actual area (projected area) of the fabric diaphragm.

[0009] Figure 2 This is a diagram showing the bent and folded surface of the fabric diaphragm of the present invention. Detailed Implementation

[0010] The fabric diaphragm of this invention has a thickness of 0.40–3.00 mm, and the ratio of the unfolded area to the actual area of ​​the fabric diaphragm is less than 1.40. Since the diaphragm is used in a high-temperature and high-pressure environment, it needs a certain thickness to withstand external forces. If the diaphragm thickness is less than 0.40 mm, it indicates that the yarn constituting the diaphragm is too fine, resulting in poor yarn tensile strength. During installation, the diaphragm is easily broken or punctured by external forces. Furthermore, because the electrolyzer operates in a high-temperature and high-pressure environment, under the continuous scouring of alkaline solution for a long time, an excessively thin diaphragm cannot withstand the external forces and will be damaged, leading to a significant reduction in its service life. If the diaphragm thickness is greater than 3.00 mm, the ion channel from the cathode to the anode is too long, resulting in increased diaphragm resistance, low ionic conductivity, high voltage in the hydrogen production equipment, and high power consumption. Considering the long service life and low resistance of the fabric diaphragm, the thickness of the fabric diaphragm of this invention is preferably 0.70–1.20 mm.

[0011] The thickness of the fabric diaphragm of the present invention must be controlled within the aforementioned certain thickness range, and the ratio of the unfolded area to the actual area of ​​the fabric diaphragm is less than 1.40. Here, the unfolded area of ​​the fabric diaphragm refers to the surface area of ​​the diaphragm within a defined region in the plane, and the actual area refers to the projected area of ​​the diaphragm within the defined region in the plane. If the ratio is greater than 1.40, it indicates that the greater the curvature of the yarn in the diaphragm, the thicker the diaphragm, the longer the ion path in the electrolytic cell, and the higher the resistance of the diaphragm. The smaller the ratio of the unfolded area to the actual area of ​​the fabric diaphragm of the present invention, the lower the curvature of the yarn in the diaphragm. On the one hand, the thickness of the diaphragm is reduced, the ion path is shortened, and the resistance of the diaphragm is reduced; on the other hand, due to the reduced curvature of the yarn, the distance between the yarns is smaller, the pore size of the resulting fabric diaphragm is smaller, the tightness of the diaphragm is improved, and the airtightness is higher. Considering the low resistance and high airtightness of the fabric diaphragm, the ratio of the unfolded area to the actual area of ​​the fabric diaphragm of the present invention is preferably 1.15 to 1.35.

[0012] The number of hairs within 1 cm of the surface of the fabric diaphragm in this invention is preferably less than 10. This invention involves post-processing the fabric diaphragm to reduce the number of hairs on its surface. If the number of hairs is too large, after the diaphragm is installed and used, the hairs on the diaphragm surface are easily carried away by the continuous flow of alkaline solution. These carried-away hairs accumulate in the pipes as the alkaline solution flows, potentially clogging the channels. Furthermore, after the hairs are carried away, the yarns in the diaphragm become loose, and the surface of the diaphragm tends to have holes, thus reducing the airtightness of the diaphragm and affecting its durability. In addition, excessive hairs on the surface of the fabric diaphragm will hinder the movement of bubbles generated in the electrolytic cell, causing more bubbles to accumulate on the diaphragm surface, thus clogging ion channels and resulting in some pores not participating in ion exchange, leading to high operating voltage. Therefore, considering the high durability of the diaphragm, the number of hairs within 1 cm of the surface of the fabric diaphragm in this invention is more preferably less than 1.

[0013] The fabric diaphragm of this invention is preferably composed of polyphenylene sulfide yarn with a fineness of 0.5 to 2.5 dtex. When the yarn fineness is the same, the finer the individual fibers constituting the yarn, the more fibers are required, resulting in more micropores between the fibers and a more fluffy yarn. Therefore, the diaphragm made from this yarn has more micropores and fewer macropores, thus improving its airtightness. Furthermore, the more micropores in the yarn, the more voids in the diaphragm, allowing more pathways for ions to pass through, resulting in lower resistance and higher ionic conductivity. However, if the individual fibers constituting the yarn are too fine, they may break during spinning due to insufficient external force, leading to poor yarn quality and increased spinning difficulty. Conversely, if the polyphenylene sulfide yarn is too fine, it indicates that the individual fibers constituting the yarn are too coarse, resulting in fewer fibers and fewer micropores between the fibers, leading to a lower porosity, higher resistance, and lower ionic conductivity in the resulting diaphragm. Considering the low resistance and high airtightness of the fabric diaphragm, the fabric diaphragm of the present invention is preferably made of polyphenylene sulfide yarn with a fineness of 0.9 to 1.5 dtex.

[0014] The warp density of the fabric diaphragm of the present invention is preferably 30-44 threads / inch, and the weft density is preferably 15-35 threads / inch. When the yarn fineness is the same, the higher the warp and weft density of the diaphragm, the larger the proportion of yarn per unit area, the higher the tightness of the diaphragm, the lower the porosity, the smaller the pores, and the better the airtightness. The lower the warp and weft density of the diaphragm, the smaller the proportion of yarn per unit area, the higher the porosity of the diaphragm, the higher the ion permeability, and the lower the resistance. Considering the low resistance and high airtightness of the fabric diaphragm, the warp density of the fabric diaphragm of the present invention is more preferably 30-38 threads / inch, and the weft density is more preferably 20-29 threads / inch.

[0015] The preferred basis weight of the fabric diaphragm of this invention is 300–1000 g / m³. 2If the basis weight is too low, it indicates insufficient fiber content, resulting in a loose and thin fabric. This tends to increase the porosity of the diaphragm and decrease its airtightness. Furthermore, the excessive thinness leads to low diaphragm stiffness, making it prone to wrinkling. Conversely, if the basis weight is too high, it indicates excessive fiber content and thickness, leading to a lower porosity of the diaphragm, less space for ions to pass through, and a tendency for increased diaphragm resistance. Considering the low resistance and high airtightness of the fabric diaphragm, the basis weight of the fabric diaphragm in this invention is more preferably 300–800 g / m². 2 Further optimization of 400-600 g / m 2 .

[0016] The ionic conductivity of the fabric diaphragm of this invention is preferably greater than 3000 S / cm. The higher the ionic conductivity of the diaphragm, the faster the ion electrolysis efficiency, the lower the voltage required for the same hydrogen production, and the lower the power consumption during hydrogen production. Considering the need to reduce operating voltage, the ionic conductivity of the fabric diaphragm of this invention is more preferably greater than 4000 S / cm.

[0017] The preferred bubble movement angle of the fabric diaphragm in water is 35° or less. The bubble movement angle is a standard for measuring the ease with which bubbles detach from the diaphragm surface in an electrolyzer. A larger bubble movement angle in water makes it harder for bubbles to detach from the diaphragm surface. When the electrolyzer is installed and in use, the generated bubbles are less likely to detach from the diaphragm with the flow of alkali solution, resulting in more bubble blockage on the diaphragm surface, hindering ion passage, reducing ion throughput, increasing the operating voltage of the hydrogen production equipment, and increasing energy consumption. Furthermore, the accumulation of bubbles on the diaphragm surface increases the probability of gas passing through the diaphragm, affecting gas purity. Therefore, to reduce operating voltage, the preferred bubble movement angle of the fabric diaphragm in water is 20° or less.

[0018] The abrasion resistance of the fabric diaphragm of the present invention is preferably above 700 cycles, more preferably above 900 cycles. This indicates that the fabric diaphragm can resist continuous erosion by alkaline solutions, has high airtightness, and a long service life.

[0019] The water absorption time of the fabric diaphragm of the present invention after treatment with 90°C and 30% KOH solution for one month is preferably less than 10 seconds. A shorter water absorption time indicates better hydrophilicity. Hydrophilic groups on the surface of the diaphragm's pores form hydrogen bonds with water molecules, increasing the strength of the connection between water molecules and the pores after wetting. The resulting water film is less easily broken by gas, thus blocking gas passage. If the water absorption time after KOH solution treatment is too long, it indicates that the hydrophilicity of the diaphragm decreases with prolonged use, hydrophilic groups fall off, and the hydrogen bonds between the diaphragm and water molecules disappear, relying solely on van der Waals forces for connection. This connection is weak, allowing gas to easily pass through, reducing the diaphragm's airtightness. Furthermore, reduced hydrophilicity also makes the diaphragm surface hydrophobic in the electrolytic cell, making it more susceptible to air bubble adhesion, which can block some micropores, leading to decreased ion throughput and increased resistance. Therefore, the water absorption time of the fabric diaphragm of the present invention after treatment with 90°C and 30% KOH solution for one month is more preferably less than 5 seconds.

[0020] The method for preparing the fabric diaphragm of the present invention includes the following steps: fibers are spun and twisted to obtain yarn; the obtained yarn is used as warp and weft yarns, and woven on a rapier loom to obtain a diaphragm fabric; the diaphragm fabric is then subjected to sulfonation, depilation, and calendering to finally obtain the fabric diaphragm. The depilation process is preferably infrared depilation or microwave depilation.

[0021] The present invention will be further illustrated by the following embodiments, but the scope of protection of the present invention is obviously not limited to the embodiments. The physical property parameters in the embodiments are determined by the following methods.

[0022] The ratio of the unfolded area to the actual area of ​​the fabric diaphragm.

[0023] The surface of the fabric diaphragm was scanned and measured using a 3D profile measuring instrument (VR-5000). Five 10cm x 10cm fabric diaphragms were prepared. The VR-5000 testing software was opened, and one diaphragm was placed flat on the stage. The fabric surface was focused by double-clicking on the display, and then the "Start" button was clicked to scan the fabric surface. The 3D profile measuring instrument automatically scanned and calculated the unfolded area S1 and the actual area S2 of the fabric diaphragm, and then automatically calculated the ratio Sdr of the unfolded area to the actual area. After scanning, the "Analyze" button was clicked, the "Roughness" test was selected, and the test result Sdr was displayed on the monitor after clicking the "All Areas" button. The diaphragm fabric was replaced, and the above steps were repeated five times. The average value of the "Sdr" value in the five tests is the ratio of the unfolded area to the actual area of ​​the fabric diaphragm.

[0024] [Number of feathers]

[0025] Cut the fabric diaphragm into 50cm x 50cm pieces, fold them along the parallel weft direction, and place them under an electron fiber microscope with magnification set to 30x. Select a length measuring tool to measure the length of the surface hairs on the fabric diaphragm, and count the number of hairs M1 that are longer than 1mm within 1cm of the folded position. Randomly select 5 positions from left to right, and the average value M of the number of hairs within 1cm of the 5 positions is the number of hairs on the surface of the fabric diaphragm.

[0026]

Warp and weft yarn density

[0027] Place the fabric analysis mirror on the flattened fabric diaphragm. Select any warp yarn and place it parallel to one side of the fabric analysis mirror. Starting from the selected warp yarn, count the number of yarns Tw1 in each window. Take any three positions, and the average number of yarns at the three positions is the warp density Tw. Then select any weft yarn and place it parallel to one side of the fabric analysis mirror. Starting from the selected weft yarn, count the number of yarns Tjl in each window. Take any three positions, and the average number of yarns at the three positions is the weft density Tj.

[0028] [Yarn fineness]

[0029] Lay the diaphragm flat on the table and remove a complete yarn from it. After straightening the yarn, cut it and weigh 100cm of the yarn, G1 (N=5). Take the average weight G of the 5 yarns and calculate the fineness D of the yarn using the formula: D = G × 10000.

[0030] [Fiber fineness]

[0031] The cross-section of the warp and weft yarns of the fabric diaphragm was imaged using a SEM electron microscope at a magnification of 200x. The diameter of the fibers in the fabric diaphragm was randomly measured, and the average of 30 measurements was taken as the diameter d of the fiber matrix material. The formula for calculating the fiber area S is as follows: S = Πd 2 / 4, The formula for calculating fiber fineness D is as follows: Fiber fineness D=ρ×9000×S×10 -6 ×(100+R) / 100, where ρ is the density of the fiber raw material and R is the standard moisture regain of the fiber raw material.

[0032] [Bubble Movement Angle]

[0033] The bubble movement angle of the diaphragm was measured using a contact angle measuring instrument (DSA30S). The diaphragm was cut into a 3×6cm rectangle (N=10), then attached to a glass slide with double-sided tape, front side (diaphragm side) facing down, and fixed in a water bath container, ensuring the diaphragm was completely submerged. The container was then placed on a stage with adjustable tilt angle. A 10μl bubble was atomized onto the diaphragm surface using the needle of the contact angle measuring instrument, allowing the bubble to adhere to the lower surface of the diaphragm. The stage was slowly tilted, and the angle of tilt was recorded after the bubble on the diaphragm surface began to move; this angle is the bubble movement angle of the diaphragm.

[0034] [Number of wear resistance cycles]

[0035] The abrasion resistance of the diaphragm was determined using a Taber abrasion tester. The diaphragm was cut into a circle with a diameter of 13 cm and mounted on the friction disc. The friction wheel (model: CS-10) and load (4.9 gf) were also installed in their respective positions. The equipment was powered on and operated automatically. The machine was stopped every 100 cycles to observe the diaphragm surface condition until two yarns on the diaphragm surface broke. The number of friction cycles at this point was recorded. The average number of friction cycles for three diaphragms was taken as the abrasion resistance test cycle for the diaphragm.

[0036]

thickness

[0037] The thickness was measured according to the standard JIS L1096-2010 for measuring the thickness of standard fabrics, in mm.

[0038]

Weight

[0039] The weight was determined according to the standard GB / T 4669-2008 for the determination of the unit area mass of woven fabrics. The formula for calculating the weight is as follows: weight (g / m²) = dry weight (g) / area (m²).

[0040] Porosity

[0041] Fabric porosity refers to the ratio of the volume of voids between fibers to the apparent volume of the fabric in a fiber-packed state. The formula for calculating porosity is as follows: Porosity = [1 - (gram weight / thickness) / PPS fiber density] × 100%.

[0042] Airtightness

[0043] According to the Chinese building materials industry standard JCT 211-2009 [Diaphragm Asbestos Cloth], the airtightness of the diaphragm was tested.

[0044] [Absorption Time]

[0045] According to section 7.1.1 of JIS L1907-2010, "Test Method for Water Absorption of Fiber Products," the water absorption time of the diaphragm was tested.

[0046] Ion conductivity

[0047] According to the People's Republic of China Electronic Industry Standard SJ / T 10171.5-1991, Test Standard for Diaphragm Surface Resistance, the surface resistance K of the diaphragm was measured, with the unit being Ω·cm. 2 The thickness d of the diaphragm was measured in μm according to the thickness measurement standard JIS L1096-2010. The ionic conductivity σ of the diaphragm was then calculated using the formula σ=d / k.

[0048]

resistance

[0049] First, place the test cell containing a 30wt% potassium hydroxide solution into an oil bath and heat it to 50℃. Test the two electrodes of the test cell with an Amber AT526 DC resistance meter; the blank resistance is R0. Then, insert a 7.3cm × 3.9cm rectangular fabric diaphragm into the fixture of the test cell; the resistance is measured as R1. The formula for calculating the resistance R of the fabric diaphragm is as follows: R = R1 - R0. Perform five tests and take the average value.

[0050] Surface resistance

[0051] According to the People's Republic of China Electronic Industry Standard SJ / T 10171.5-91 Test Standard for Surface Resistance of Alkaline Battery Separator, the surface resistance of the fabric separator is tested.

[0052] Example 1

[0053] PPS fibers with a fineness of 1.5 dtex were spun and twisted to produce yarn with a fineness of 1687 dtex. The resulting yarn was used as warp and weft yarns and woven on a rapier loom to produce diaphragm fabric. The diaphragm fabric was then subjected to sulfonation, infrared depilation, and calendering processes to finally produce a warp density of 35 threads / inch, a weft density of 26 threads / inch, and a weight of 455 g / m². 2 A fabric diaphragm with a thickness of 0.81 mm was used. The ratio of the unfolded area to the actual area of ​​the fabric diaphragm was measured to be 1.21. The number of hairs within 1 cm of the surface of the fabric diaphragm was less than 1. The physical properties of the fabric diaphragm of the present invention are shown in Table 1 below.

[0054] Examples 2 and 3

[0055] The preparation process is the same as in Example 1, and the specific formulation and properties are shown in Table 1.

[0056] Example 4

[0057] PPS fibers with a fineness of 1.5 dtex were spun and twisted to produce yarn with a fineness of 1687 dtex. The resulting yarn was used as warp and weft yarns and woven on a rapier loom to produce diaphragm fabric. The diaphragm fabric was then subjected to sulfonation, microwave depilation, and calendering processes to finally produce a warp density of 35 threads / inch, a weft density of 26 threads / inch, and a weight of 455 g / m². 2 A fabric diaphragm with a thickness of 0.82 mm was used. The ratio of the unfolded area to the actual area of ​​the fabric diaphragm was measured to be 1.20, and the number of hairs was 4 per cm. The physical properties of the fabric diaphragm of this invention are shown in Table 1 below.

[0058] Examples 5-8

[0059] The preparation process is the same as in Example 1, and the specific formulation and properties are shown in Table 1.

[0060] Example 9

[0061] PPS fibers with a fineness of 1.5 dtex were spun and twisted to produce yarn with a fineness of 590.5 dtex. This yarn was then used as warp and weft yarns and woven on a rapier loom to produce a diaphragm fabric. The diaphragm fabric was then subjected to sulfonation and infrared depilation processes to ultimately produce a warp density of 55 threads / inch, a weft density of 38 threads / inch, and a weight of 255 g / m². 2 A fabric diaphragm with a thickness of 0.41 mm was used. The ratio of the unfolded area to the actual area of ​​the fabric diaphragm was measured to be 1.13. The number of hairs within 1 cm of the surface of the fabric diaphragm was less than 1. The physical properties of the fabric diaphragm of the present invention are shown in Table 1 below.

[0062] The fabric diaphragms in Examples 1-9 are used in water electrolysis hydrogen production equipment.

[0063] Comparative Example 1

[0064] PPS fibers with a fineness of 1.5 dtex were spun and twisted to produce yarn with a fineness of 492 dtex. The resulting yarn was used as warp and weft yarns and woven on a rapier loom to produce diaphragm fabric. The diaphragm fabric was then subjected to sulfonation, infrared depilation, and calendering processes to finally produce a warp density of 55 threads / inch, a weft density of 38 threads / inch, and a weight of 230 g / m². 2 A fabric diaphragm with a thickness of 0.35 mm was used. The ratio of the unfolded area to the actual area of ​​the fabric diaphragm was measured to be 1.10. The number of hairs within 1 cm of the surface of the fabric diaphragm was less than 1. The physical properties of the diaphragm are shown in Table 2 below.

[0065] Comparative Example 2

[0066] PPS fibers with a fineness of 1.5 dtex were spun and twisted to produce yarn with a fineness of 1968 dtex. This yarn was then used as warp and weft yarns and woven on a rapier loom to produce a diaphragm fabric. The diaphragm fabric was then subjected to sulfonation and infrared depilation processes to ultimately produce a warp density of 33 threads / inch, a weft density of 25 threads / inch, and a weight of 490 g / m². 2 A fabric diaphragm with a thickness of 0.93 mm was used. The ratio of the unfolded area to the actual area of ​​the fabric diaphragm was measured to be 1.52. The number of hairs within 1 cm of the surface of the fabric diaphragm was less than 1. The physical properties of the diaphragm are shown in Table 2 below.

[0067] Comparative Example 3

[0068] PPS fibers with a fineness of 1.5 dtex were spun and twisted to produce yarn with a fineness of 1687 dtex. The resulting yarn was used as warp and weft yarns and woven on a rapier loom to produce diaphragm fabric. The diaphragm fabric was then subjected to sulfonation and calendering processes to finally produce a warp density of 35 threads / inch, a weft density of 26 threads / inch, and a weight of 455 g / m². 2 A fabric diaphragm with a thickness of 0.82 mm was used. The ratio of the unfolded area to the actual area of ​​the diaphragm was measured to be 1.20, and the number of fibers was 30 / cm. The physical properties of the diaphragm are shown in Table 2 below.

[0069] Table 1

[0070]

[0071] Table 2

[0072]

[0073] According to the table above,

[0074] (1) As can be seen from Examples 1 and 2, under the same conditions, the thickness of the fabric diaphragm in the former is within the preferred range. Compared with the latter, the fabric diaphragm in the former has higher air tightness and higher ionic conductivity.

[0075] (2) As can be seen from Examples 1 and 3, under the same conditions, the ratio of the unfolded area to the actual area of ​​the fabric diaphragm in the former is within the preferred range. Compared with the latter, the fabric diaphragm of the former has higher air tightness.

[0076] (3) As can be seen from Examples 1 and 4, under the same conditions, the number of hairs in the fabric diaphragm in the former is within the preferred range. Compared with the latter, the bubble movement angle of the fabric diaphragm in the former is smaller and the number of wear resistances is more, that is, the durability is higher.

[0077] (4) As can be seen from Examples 3 and 5, under the same conditions, the fiber fineness of the fabric diaphragm in the former is within a better range. Compared with the latter, the fabric diaphragm of the former has higher air tightness, lower resistance and higher ionic conductivity.

[0078] (5) As can be seen from Examples 3 and 6, under the same conditions, the warp and weft density of the fabric diaphragm in the former is in a better range. Compared with the latter, the fabric diaphragm of the former has lower resistance and higher ionic conductivity.

[0079] (6) As can be seen from Examples 1 and 7, under the same conditions, the basis weight of the fabric diaphragm in the former is within a better range. Compared with the latter, the fabric diaphragm of the former has better air tightness and more wear resistance, that is, higher durability.

[0080] (7) As can be seen from Example 1 and Comparative Example 1, under the same conditions, the thickness of the diaphragm in the latter is too low. Compared with the former, the air tightness of the diaphragm in the latter is low and the number of wear resistance cycles is low, that is, the wear resistance is poor.

[0081] (8) As can be seen from Example 1 and Comparative Example 2, under the same conditions, the ratio of the unfolded area to the actual area of ​​the diaphragm in the latter is too high. Compared with the former, the airtightness of the diaphragm in the latter is low.

[0082] (9) As can be seen from Example 1 and Comparative Example 3, under the same conditions, the latter has too many hairs on the diaphragm. Compared with the former, the latter diaphragm has fewer wear resistance times, that is, poor wear resistance.

Claims

1. A fabric diaphragm, characterized in that: The fabric diaphragm has a thickness of 0.40 to 3.00 mm, and the ratio of the unfolded area of ​​the fabric diaphragm to the actual area is less than 1.

40. The number of hairs on the surface of the fabric diaphragm within 1 cm is less than 10.

2. The fabric diaphragm according to claim 1, characterized in that: The fabric diaphragm is made of polyphenylene sulfide fibers with a fineness of 0.5 to 2.5 dtex.

3. The fabric diaphragm according to claim 1, wherein the warp density of the fabric diaphragm is 30-44 threads / inch and the weft density is 15-35 threads / inch.

4. The fabric diaphragm according to claim 1, characterized in that: The fabric diaphragm has a basis weight of 300–1000 g / m³. 2 .

5. The fabric diaphragm according to claim 1, characterized in that: The ionic conductivity of the fabric diaphragm is greater than 3000 S / cm.

6. The fabric diaphragm according to claim 1, characterized in that: The fabric diaphragm allows air bubbles to move at an angle of less than 35° in water.

7. The fabric diaphragm according to claim 1, characterized in that: The fabric diaphragm has an abrasion resistance of over 700 cycles.

8. The fabric diaphragm according to claim 1, characterized in that: The absorbency time of the fabric diaphragm after treatment with 90°C and 30% KOH solution for one month is less than 10 seconds.

9. The application of the fabric diaphragm according to claim 1 in a water electrolysis hydrogen production device.

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