Device and method for reducing oil on membrane area of diaphragm

Abstract

The invention discloses a device and method for reducing diaphragm surface oil, the device for reducing diaphragm surface oil comprises an air knife mechanism arranged behind a TDO1 chain clamp platform, the air knife mechanism comprises a support and an air knife fixed on the support, the air knife comprises a long-strip-shaped air knife body, the air knife body is parallel to the diaphragm surface, and the air knife body is fixed on the support. The extending direction of the air knife body is perpendicular to the length direction of the diaphragm, one end of the air knife body is connected with an air inlet pipe, an air outlet extending along the air knife body is formed in one side of the air knife body, the length of the air outlet is larger than the width of the diaphragm face, and the air outlet is obliquely arranged downwards and used for blowing the diaphragm face. The air outlet in the air knife body is of a long flat opening structure and covers the complete film face of the TDO1 inlet, compressed air strong blowing wind power is used for blowing oil on the film face outwards, and therefore accumulated oil is reduced, and oil throwing thin points are reduced. The air knife body is fixed through the support, and the angle and the position of the air outlet are not prone to change after being fixed.

Description

Technical Field

[0001] The invention relates to a device and a method for reducing the oil content of a diaphragm membrane area, belonging to the technical field of lithium battery diaphragm production. Background Art

[0002] Thin spots are one of the abnormal surface defects in the production of lithium battery diaphragms. During the production process, oil accumulates on the production line and falls onto the membrane surface, forming thin spots with high local grayscale values ​​on the membrane surface or embedded in the membrane. The oil-spinning thin spots generated in the TDO1 process, i.e., the transverse stretching process, during the wet asynchronous stretching production process are due to the fact that a large amount of oil is easily accumulated at multiple locations such as the membrane surface, chain clamp, and closer, and falls onto the diaphragm surface and enters the transverse stretching, resulting in oblique long thin spots with a transverse stretching trend, i.e., oil-spinning thin spots. The solution to the oil-spinning thin spots among the thin spot types is quite difficult. The solution of the prior art is to add an air nozzle before the TDO1 process section to purge the membrane surface, chain clamp, and other locations to achieve the effect of reducing oil accumulation. This air nozzle is a round-mouth air nozzle or a flat-mouth air nozzle. The oil purge efficiency of the membrane area is maximized by adjusting the angle, air volume, and number of air nozzles.

[0003] However, the angle and position of the air nozzle are difficult to fix, and the purge area of ​​the air nozzle is small. The air nozzle may be accidentally touched during the production process or due to various reasons, resulting in changes in the angle and position of the air nozzle. Therefore, the oil-thin spot is not improved well, and even the oil-thin spot at the TDO1 inlet will occur again, reducing the quality rate of the diaphragm. Summary of the invention

[0004] The purpose of the present invention is to provide a device for reducing the oil on the membrane area of ​​the diaphragm, so as to solve the technical problem that the air nozzle used in the transverse stretching process of the prior art diaphragm has a small blowing area, and the angle and position are easily changed, resulting in the failure to improve the oil-thinning point. At the same time, the present invention also provides a method for reducing the oil on the membrane area of ​​the diaphragm.

[0005] The device for reducing the oil on the diaphragm membrane surface of the present invention adopts the following technical scheme: a device for reducing the oil on the diaphragm membrane surface, which includes a wind knife mechanism arranged behind the TDO1 chain clamp platform, the wind knife mechanism includes a bracket and a wind knife fixed on the bracket, the wind knife includes a long wind knife body, the wind knife body is parallel to the diaphragm membrane surface, the extension direction of the wind knife body is perpendicular to the length direction of the diaphragm, one end of the wind knife body is connected to an air inlet pipe, and one side of the wind knife body is provided with an air outlet extending along the wind knife body, the length of the air outlet is greater than the width of the diaphragm membrane surface, and the air outlet is arranged obliquely downward to blow the diaphragm membrane surface.

[0006] The wind knife body adopts a rectangular box-shaped structure. A tapered opening that gradually shrinks from the inside to the outside is provided on the side of the wind knife body facing the diaphragm surface. The extension direction of the tapered opening is consistent with the extension direction of the wind knife body. The air outlet is located at the outermost side of the tapered opening.

[0007] The bracket comprises supports located on both sides of the diaphragm and a support shaft installed between the two supports. A wind knife fixing sleeve is fixed on the support shaft, and the surface of the wind knife fixing sleeve has a plane for fixing the wind knife body.

[0008] The wind knife fixing sleeve adopts an annular structure with a notch. The wind knife fixing sleeve is arranged behind the supporting shaft, and a fixing bolt is connected to the notch; an L-shaped connecting plate is fixed on the plane of the wind knife fixing sleeve, and the wind knife body is fixedly connected to the L-shaped connecting plate.

[0009] The support includes a vertical sheet metal, a transverse sheet metal and a support sleeve. The vertical sheet metal is provided with a hole for the support shaft to pass through, and the ends of the support shaft pass through the vertical sheet metal and the support sleeve in turn. The vertical sheet metal has a vertical support surface, and the transverse sheet metal has a horizontal support surface. One end of the transverse sheet metal is fixedly connected to a rib parallel to the vertical support surface, and the other end is fixedly connected to a lower plate that is fitted and fixed to the vertical support surface. The support sleeve is clamped between the vertical support surface and the rib. The bottom surface of the support sleeve is a plane fixedly connected to the horizontal support surface of the transverse sheet metal. The top of the support sleeve has an opening, and the opening of the support sleeve is fixed by bolts. The rib has an arc groove for the support shaft to pass through.

[0010] The end surface of the support sleeve close to the retaining edge is provided with scale lines, and the scale lines are distributed on the outer periphery of the central hole of the support sleeve; the support shaft is provided with scale lines on the circumference of the outer side of the support sleeve.

[0011] The distance between the air outlet and the diaphragm membrane surface is 5-15cm (for example, it can be 5cm, 6cm, 8cm, 10cm, 12cm, 14cm, 15cm), the angle between the air outlet and the diaphragm membrane surface is 30-60° (for example, it can be 35°, 38°, 40°, 42°, 45°, 50°, 55°, 60°), the width of the air outlet is less than 4mm (for example, it can be 1mm, 2mm, 3mm, or 4mm), and the length of the air outlet is 600~800mm (for example, 600mm, 650mm, 700mm, 750mm, or 800mm).

[0012] An EPC guiding system is installed between the TDO1 chain clamp platform and the guide roller before the TDO1 chain clamp platform. The EPC guiding system is made of stainless steel.

[0013] An oil scraping roller is arranged before the guide roller, and an oil scraping plate is arranged on one side of the oil scraping roller, and the oil scraping plate is made of silica gel.

[0014] The method for reducing the oil on the diaphragm membrane area of ​​the present invention adopts the following technical scheme: a method for reducing the oil on the diaphragm membrane area, which is carried out by adopting the above-mentioned device for reducing the oil on the diaphragm membrane area, and the air outlet of the wind knife mechanism is set at a position of 5-15cm (for example, it can be 5cm, 6cm, 8cm, 10cm, 12cm, 14cm, 15cm) above the diaphragm membrane surface, and the angle of the air outlet is 30-60° (for example, it can be 35°, 38°, 40°, 42°, 45°, 50°, 55°, 60°) to the membrane surface, and 0.4-0.55Mpa compressed air is introduced into the wind knife body, and the compressed air is discharged from the air outlet to form a wind knife, and the diaphragm membrane surface is blown by the wind knife.

[0015] The beneficial effects of the present invention are as follows: the air outlet in the air knife body of the present invention is a long flat opening structure, covering the complete membrane surface of the TDO1 inlet, and using the strong blowing force of compressed air to blow the oil on the membrane surface outward, thereby reducing oil accumulation and reducing oil-stripping thin points. The air knife body of the present invention is fixed by a bracket, and once fixed, the angle and position of the air outlet are not easy to change. The air knife has a long strip-shaped air outlet and a large blowing area, which can sweep the entire membrane surface, ensure the blowing force and area, improve the blowing efficiency, and improve the oil-stripping thin points.

[0016] Preferably, a conical opening is provided on the air knife body, which is beneficial to improving the uniformity and stability of the air outlet pressure.

[0017] Preferably, the wind knife fixing sleeve is used to support the wind knife body, so that the fixation of the wind knife body is more stable and the position and angle of the air outlet are not easy to change.

[0018] Preferably, the height of the support determines the height of the wind knife body, and the position of the support can be changed by changing the connection position of the vertical sheet metal and the lower plate, and the vertical sheet metal and the lower plate are fixed by tightening screws.

[0019] Preferably, the adjustment of the wind knife angle can be positioned by the scale lines. By loosening the bolts on the opening of the support sleeve and rotating the support shaft, the angle of the wind knife outlet rotates with the rotation of the support shaft. After the outlet angle is adjusted to the right position, tighten the bolts on the opening of the support sleeve to fix the angle of the wind knife outlet.

[0020] Preferably, the surface of the EPC correction system made of stainless steel is smooth and has no grooves, and the oil droplets blown by the wind knife are not easy to accumulate on its surface, avoiding dripping on the membrane surface to form large thin point defects. The scraper roller and scraper plate can scrape off the oil droplets on the diaphragm. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an overall schematic diagram of a device for reducing oil on the membrane area of ​​a diaphragm according to an embodiment of the present invention; Figure 2 yes Figure 1 Left view of; Figure 3 yes Figure 2 Schematic diagram of the installation process of the middle bracket and the air knife on the support; Figure 4 yes Figure 3 An enlarged view of the wind knife installed on the support; Figure 5 yes Figure 2 Schematic diagram of the middle support; Figure 6 yes Figure 5 Left view of; Figure 7 It is the statistical situation of thin point rolls of the diaphragm production line before and after using the present invention.

[0022] In the figure: 1-wind knife, 1.1-wind knife body, 1.2-air outlet, 1.3-conical mouth, 2-bracket, 2.1-support, 2.11-vertical sheet metal, 2.12-support sleeve, 2.13-horizontal sheet metal, 2.14-rib, 2.15-lower plate, 2.2-support shaft, 2.21-wind knife fixing sleeve, 2.22-connecting plate, 3-TDO1 chain clamp platform, 4-guide roller, 5-EPC correction system, 6-oil scraper roller, 7-oil scraper plate, 8-diaphragm. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1 to 6 As shown, a device for reducing the oil on the diaphragm membrane surface according to an embodiment of the present invention includes a wind knife mechanism arranged behind the TDO1 chain clamp platform 3, the wind knife mechanism includes a bracket 2 and a wind knife 1 fixed on the bracket 2, the wind knife 1 includes a long wind knife body 1.1, the wind knife body 1.1 is parallel to the diaphragm membrane surface, the extension direction of the wind knife body 1.1 is perpendicular to the length direction of the diaphragm 8, one end of the wind knife body 1.1 is connected to an air inlet pipe (not shown in the figure), the air inlet pipe is used to introduce compressed gas into the wind knife body, one side of the wind knife body 1.1 is provided with an air outlet 1.2 extending along the wind knife body, the length of the air outlet 1.2 is greater than the width of the diaphragm membrane surface, and the air outlet 1.2 is arranged obliquely downward to blow the diaphragm membrane surface. The wind knife body 1.1 adopts a rectangular box-shaped structure, and a tapered opening 1.3 which gradually decreases from the inside to the outside is provided on the side of the wind knife body 1.1 facing the membrane surface, and the extension direction of the tapered opening 1.3 is consistent with the extension direction of the wind knife body 1.1, and the air outlet is located at the outermost side of the tapered opening 1.3. The distance between the air outlet 1.2 and the membrane surface of the membrane 8 is 6-10cm, and there is an angle of 30-60° between the air outlet 1.2 and the membrane surface of the membrane 8, the width of the air outlet 1.2 is less than 2mm, and the length of the air outlet 1.2 is 700mm.

[0025] like Figure 3 to Figure 4 As shown, the bracket 2 includes a support 2.1 located on both sides of the diaphragm 8 and a support shaft 2.2 installed between the two supports 2.1, and a wind knife fixing sleeve 2.21 is fixed on the support shaft 2.2, and the surface of the wind knife fixing sleeve 2.21 has a plane for fixing the wind knife body 1.1. The wind knife fixing sleeve 2.21 adopts an annular structure with a notch, and the wind knife fixing sleeve 2.21 is sleeved behind the support shaft, and a fixing bolt is connected to the notch; an L-shaped connecting plate 2.22 is fixed on the plane of the wind knife fixing sleeve 2.21, and the wind knife body 1.1 is fixedly connected to the L-shaped connecting plate 2.22. The connecting plate 2.22 is welded to the wind knife fixing sleeve 2.21.

[0026] like Figure 5 to Figure 6 As shown, the support 2.1 includes a vertical sheet metal 2.11, a horizontal sheet metal 2.13 and a support sleeve 2.12. The vertical sheet metal 2.11 is provided with a hole for the support shaft 2.2 to pass through. The end of the support shaft 2.2 passes through the vertical sheet metal 2.11 and the support sleeve 2.12 in sequence. The length of the support shaft 2.2 is 1100~1300mm (for example, 1100mm, 1150mm, 1200mm, 1250mm, 1300mm), and can be selected as 1200mm. It is made of steel pipe. The vertical sheet metal 2.11 has a vertical support surface, and the horizontal sheet metal 2.13 has a horizontal support surface. One end of the horizontal sheet metal 2.13 is fixedly connected to a retaining edge 2.14 parallel to the vertical support surface, and the other end is fixedly connected to a lower plate 2.15 that fits and fixes the vertical support surface. The support sleeve 2.12 is clamped between the vertical support surface and the retaining edge 2.14. The bottom surface of the support sleeve 2.12 is a plane fixedly connected to the horizontal support surface of the horizontal sheet metal. The top of the support sleeve 2.12 has an opening, and the opening of the support sleeve 2.12 is fixed by bolts. The retaining edge 2.14 has an arc groove for the support shaft to pass through. The support sleeve 2.12 is provided with scale lines (not shown in the attached figure) on the end surface close to the retaining edge, and the scale lines are distributed on the periphery of the center hole of the support sleeve; the support shaft 2.2 is provided with scale lines (not shown in the attached figure) on the circumference of the outer side of the support sleeve 2.12. The adjustment of the wind knife angle can be positioned by the scale lines. By loosening the bolts on the support sleeve opening and rotating the support shaft, the angle of the wind knife air outlet rotates with the rotation of the support shaft. After the air outlet angle is adjusted to the right position, tighten the bolts on the support sleeve opening to fix the air knife air outlet angle.

[0027] An EPC correction system 5 is provided between the TDO1 chain clamp platform 3 and the guide roller 4 before the TDO1 chain clamp platform 3. The EPC correction system 5 is made of stainless steel. The surface of the EPC correction system is smooth and has no grooves. The oil droplets blown by the wind knife are not easy to accumulate on the surface to form beads, so as to avoid dripping on the film surface to form large thin point defects. An oil scraper roller 6 is provided before the guide roller 4. An oil scraper plate 7 is provided on one side of the oil scraper roller 6. The oil scraper plate 7 is made of silicone. The oil scraper plate 7 contacts the roller surface of the oil scraper roller 6, and the downward pressure of the oil scraper plate on the roller surface is increased or decreased depending on the degreasing effect.

[0028] A method for reducing the oil on the diaphragm membrane surface according to an embodiment of the present invention is performed using the above-mentioned device for reducing the oil on the diaphragm membrane surface, wherein an air outlet of the wind knife mechanism is set at a position of 6-10 cm (for example, 6 cm, 7 cm, 8 cm, 9 cm, 10 cm) above the diaphragm membrane surface, and the angle of the air outlet is 35°-45° to the membrane surface. Compressed air of 0.4-0.55 MPa is introduced into the wind knife body, and the compressed air is discharged from the air outlet to form a wind knife, and the diaphragm membrane surface is blown by the wind knife.

[0029] The present invention sets a wind knife mechanism behind the TDO1 chain clamp platform. Two supports in the wind knife bracket are respectively fixedly installed on both sides of the TDO1 inlet chain clamp platform. The height of the wind knife body can be changed by changing the position of the supports. The support shaft in the wind knife bracket is used to support the wind knife body. The wind knife fixing sleeve can stably install the wind knife body on the support shaft so that the wind knife body is located above the membrane surface. The angle of the wind knife outlet can be adjusted by rotating the support shaft. After the angle is adjusted, the two ends of the support shaft are locked on the support by the support sleeve to prevent the wind knife from moving during use. The running direction of the diaphragm is as follows: Figure 1 In the direction indicated by the middle arrow, during purging, compressed gas is introduced into the air knife body through the air inlet pipe, and the air outlet is directed obliquely downward toward the membrane surface to purge the oil droplets on the membrane surface.

[0030] The air outlet in the air knife body of the present invention is a long flat mouth structure, covering the complete membrane surface of the TDO1 inlet, and using the strong blowing force of compressed air to blow the oil on the membrane surface outward, so as to reduce oil accumulation and reduce the thin points of oil throwing. The material of the air knife body is stainless steel, and the middle interior is a compressed air flow channel. The height of the air knife body is determined by the height of the support. The position of the support can be changed by changing the connection position of the vertical sheet metal and the lower plate, and the vertical sheet metal and the lower plate are fixed by tightening screws. Compressed air is introduced into the air knife body through the single-sided injection port, and the air volume can be controlled by adjusting the compressed air pressure. The standard compressed air supply pressure is usually 0.5Mpa.

[0031] After actual on-site testing, the air knife outlet is 6-10cm away from the membrane surface, the outlet angle is 35°-45° to the membrane surface, the compressed air is 0.4-0.55Mpa, the air volume is uniform and stable, and it can blow away the oil droplets on the membrane surface without blowing the membrane surface wrinkles. At this time, the oil on the TDO1 inlet membrane area is greatly reduced, and the oil thinning points are reduced. Different production lines adjust the optimal height, angle, and air volume according to actual conditions.

[0032] The present invention can effectively improve the purging efficiency of the oil accumulation at the TDO1 inlet, reduce the occurrence of thin spots at the TDO1 inlet, and improve the quality rate of diaphragm products. The cumulative thin spot defective ratio of the original production line is 6.6% per month. After using the air knife, the number of thin spots is significantly reduced, and the cumulative thin spot defective ratio per month is 1.25%. The thin spot volume statistics of the diaphragm production line before and after using the present invention are as follows: Figure 7 As shown in the table.

Claims

1. A device for reducing the oil content of a diaphragm membrane, characterized in that: It includes a wind knife mechanism arranged behind the TDO1 chain clamp platform, the wind knife mechanism includes a bracket and a wind knife fixed on the bracket, the wind knife includes a long wind knife body, the wind knife body is parallel to the diaphragm membrane surface, the extension direction of the wind knife body is perpendicular to the length direction of the diaphragm, one end of the wind knife body is connected to an air inlet pipe, and one side of the wind knife body is provided with an air outlet extending along the wind knife body, the length of the air outlet is greater than the width of the diaphragm membrane surface, and the air outlet is arranged obliquely downward to blow the diaphragm membrane surface.

2. The device for reducing diaphragm membrane area oil according to claim 1, characterized in that: The wind knife body adopts a rectangular box-shaped structure. A tapered opening that gradually shrinks from the inside to the outside is provided on the side of the wind knife body facing the diaphragm surface. The extension direction of the tapered opening is consistent with the extension direction of the wind knife body. The air outlet is located at the outermost side of the tapered opening.

3. The device for reducing diaphragm membrane area oil according to claim 1, characterized in that: The bracket comprises supports located on both sides of the diaphragm and a support shaft installed between the two supports. A wind knife fixing sleeve is fixed on the support shaft, and the surface of the wind knife fixing sleeve has a plane for fixing the wind knife body.

4. The device for reducing diaphragm membrane area oil according to claim 3, characterized in that: The wind knife fixing sleeve adopts an annular structure with a notch. The wind knife fixing sleeve is arranged behind the supporting shaft, and a fixing bolt is connected to the notch; an L-shaped connecting plate is fixed on the plane of the wind knife fixing sleeve, and the wind knife body is fixedly connected to the L-shaped connecting plate.

5. The device for reducing diaphragm membrane area oil according to claim 3, characterized in that: The support includes a vertical sheet metal, a transverse sheet metal and a support sleeve. The vertical sheet metal is provided with a hole for the support shaft to pass through, and the ends of the support shaft pass through the vertical sheet metal and the support sleeve in turn. The vertical sheet metal has a vertical support surface, and the transverse sheet metal has a horizontal support surface. One end of the transverse sheet metal is fixedly connected to a rib parallel to the vertical support surface, and the other end is fixedly connected to a lower plate that is fitted and fixed to the vertical support surface. The support sleeve is clamped between the vertical support surface and the rib. The bottom surface of the support sleeve is a plane fixedly connected to the horizontal support surface of the transverse sheet metal. The top of the support sleeve has an opening, and the opening of the support sleeve is fixed by bolts. The rib has an arc groove for the support shaft to pass through.

6. The device for reducing diaphragm membrane area oil according to claim 5, characterized in that: The end surface of the support sleeve close to the retaining edge is provided with scale lines, and the scale lines are distributed on the outer periphery of the central hole of the support sleeve; the support shaft is provided with scale lines on the circumference of the outer side of the support sleeve.

7. The device for reducing diaphragm membrane area oil according to claim 1, characterized in that: The distance between the air outlet and the membrane surface is 5-15 cm, the angle between the air outlet and the membrane surface is 30-60°, the width of the air outlet is less than 4 mm, and the length of the air outlet is 600-800 mm.

8. The device for reducing diaphragm membrane area oil according to claim 1, characterized in that: An EPC guiding system is installed between the TDO1 chain clamp platform and the guide roller before the TDO1 chain clamp platform. The EPC guiding system is made of stainless steel.

9. The device for reducing diaphragm membrane area oil according to claim 8, characterized in that: An oil scraping roller is arranged before the guide roller, and an oil scraping plate is arranged on one side of the oil scraping roller, and the oil scraping plate is made of silica gel.

10. A method for reducing the oil content of a diaphragm membrane, characterized in that: The method is carried out by using the device for reducing the oil on the diaphragm membrane surface as described in any one of claims 1 to 9, wherein the air outlet of the wind knife mechanism is arranged at a position of 5 to 15 cm above the diaphragm membrane surface, the angle of the air outlet is 30 to 60 degrees to the membrane surface, 0.4 to 0.55 MPa compressed air is introduced into the wind knife body, and the compressed air is discharged from the air outlet to form a wind knife, and the diaphragm membrane surface is blown by the wind knife.

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