A method of winding a diaphragm

Abstract

The present application relates to a kind of winding method of diaphragm, diaphragm is wound on spindle-shaped core, realize the winding of diaphragm, obtain diaphragm roll;Spindle-shaped core is composed of coaxial circular table I and circular table II, the major end of circular table I and circular table II is consistent and same in diameter, the included angle of generatrix of circular table I and central axis is 0.2-0.4 °, the included angle of generatrix of circular table II and central axis is 0.2-0.4 °;Winding tension is 0.05-0.30N / mm;Winding taper is 0.6-3%;The width of diaphragm roll is 50-1000mm;Winding length≤5000m.The method of the present application is simple, can effectively solve the problem of diaphragm temperature difference fold.

Description

Technical Field

[0001] This invention belongs to the field of diaphragm processing and relates to a method for winding diaphragms. Background Technology

[0002] Traditional film products often use cylindrical cores made of paper or plastic during the slitting and winding process, depending on customer needs. This method is widely used due to its ease of unwinding and good winding performance, and diaphragm products also follow this approach. However, diaphragm products differ from conventional film products. Conventional film products are essentially non-porous internally, while diaphragm products have an internal porous structure with a porosity of approximately 35-50%. This means that 35-50% of the volume of a slitting roll of diaphragm product is gas. When the diaphragm product moves from an environment below 15°C to a production environment of around 25°C, the expansion of the gas in the diaphragm pores will be much greater than that of the diaphragm itself. For example, polypropylene diaphragm has a coefficient of thermal expansion of 1.2 × 10⁻⁶. -4 / ℃, the coefficient of thermal expansion of the gas is 3.67×10 -3 At ℃, the coefficient of thermal expansion of gases is about 30.6 times that of polypropylene. Although the diaphragm has a certain degree of air permeability, when multiple layers are stacked, the air permeability almost disappears. Therefore, when the gas expands due to heat, it cannot be discharged quickly. The gas expansion generates a large internal stress on the diaphragm roll, causing creases. This situation often occurs in winter. The lower the outdoor temperature, the greater the porosity of the diaphragm and the thinner the product, the more serious the situation becomes. During summer transportation, when the diaphragm product moves from a 25℃ production environment to an environment above 40℃, it also faces the same problem. The higher the outdoor temperature, the greater the porosity of the diaphragm and the thinner the product, the more serious the situation becomes.

[0003] To improve this situation, companies often use temperature-controlled warehouses that are close to the production environment for storage, and use transport vehicles with better insulation or temperature-controlled transport vehicles during transportation. Although the wrinkling caused by temperature difference is improved, temperature-controlled warehouses and temperature-controlled vehicles greatly increase the company's operating costs. Summary of the Invention

[0004] The purpose of this invention is to solve the problems existing in the prior art and provide a method for winding a diaphragm.

[0005] To achieve the above objectives, the present invention adopts the following solution:

[0006] A method for winding a diaphragm involves winding the diaphragm onto a spindle-shaped core to achieve diaphragm winding and obtain a diaphragm roll. The spindle-shaped core consists of coaxial frustum I and frustum II, with their large ends touching and having the same diameter. The angle between the generatrix of frustum I and the central axis is 0.2-0.4°, and the angle between the generatrix of frustum II and the central axis is also 0.2-0.4°. The winding tension is 0.05-0.30 N / mm, the winding taper is 0.6-3%, the width of the diaphragm roll is 50-1000 mm, and the winding length (i.e., the length of the diaphragm in a single diaphragm roll) is ≤5000 m.

[0007] This invention can solve the problem of creases caused by temperature differences in the diaphragm because: Figure 1 and Figure 2 As shown, the gap 2 between the layers on both sides is larger than the gap 1 between the layers in the middle. During the winding process, a channel with an increasing size from the inside to the outside will be formed. When gas comes out of the diaphragm, it can be quickly discharged through this channel, preventing it from being trapped inside and causing the diaphragm to be subjected to large internal stress. The main factors affecting the venting effect of this channel are: a) winding tension and winding taper (winding taper refers to the rate of change of the winding tension; the control of gradually decreasing the tension of the roll as the roll diameter increases is called taper tension control). Both should be controlled within a reasonable range so that the diaphragm... a) The roll should not be too tight, as this will block the channel; nor should it be too loose, as this will cause the diaphragm to unwind. b) The angle of the core (i.e., the angle between the generatrix of frustum I and the central axis, and the angle between the generatrix of frustum II and the central axis) should not be too small, as this will result in small gaps in the diaphragm and difficulty in gas expulsion; if it is too large, the core will be uneven and prone to wrinkles. c) The width of the diaphragm roll should not be too large, as this is equivalent to a long channel for gas expulsion, resulting in too much resistance and making it difficult to expel gas quickly. d) The winding length of the diaphragm roll should not be too long, as this will cause a large overall shrinkage of the diaphragm, making the inside of the roll tighter and thus affecting the venting effect.

[0008] Existing technology uses conventional winding cores, such as Figure 3 As shown, after winding, the gaps at various positions in the axial direction of the core are basically the same, and the overall winding is relatively tight, which makes it difficult for gas to be discharged quickly (it can be discharged, but at a slow speed, which causes wrinkles to appear on the diaphragm first, and the wrinkles disappear after the gas is slowly discharged, leaving the previous wrinkle marks on the film).

[0009] With the adoption of a new type of core, the film is relatively tight in the middle and relatively loose on both sides when it is wound up. The gap between the film and the film on both sides is different, and gas can be discharged at a faster speed at the relatively larger gap on both sides.

[0010] As a preferred technical solution:

[0011] In the diaphragm winding method described above, the angle between the generatrix of frustum I and the central axis is the same as the angle between the generatrix of frustum II and the central axis. If the two are not the same, although the problem of creases caused by temperature difference in the diaphragm can be solved, the membrane roll will be unbalanced during rotation and is prone to jumping, resulting in uneven end face defects.

[0012] In the diaphragm winding method described above, the angle between the generatrix of the frustum I and the central axis is 0.3°.

[0013] In the diaphragm winding method described above, the lengths of frustum I and frustum II are the same. If they are not the same, although the problem of creases caused by temperature difference in the diaphragm can be solved, the membrane roll will be unbalanced during rotation and will easily jump, resulting in uneven end face defects.

[0014] In the diaphragm winding method described above, the large end diameter of the frustum I is 76.5-204 mm.

[0015] In the diaphragm winding method described above, both frustum I and frustum II have hollow portions inside, and the hollow portions of the two are coaxial.

[0016] In the diaphragm winding method described above, the length of the spindle-shaped core is 55-1050 mm.

[0017] In the diaphragm winding method described above, the length of the spindle-shaped core is 55-600 mm.

[0018] In the diaphragm winding method described above, the spindle-shaped core is made of paper or plastic.

[0019] The diaphragm winding method described above has a winding tension of 0.14-0.25 N / mm, a winding taper of 1.0-2.0%, and a diaphragm roll width of 50-600 mm.

[0020] In the diaphragm winding method described above, during the winding process, the deviation between the middle position of the diaphragm roll and the intersection position of frustum I and frustum II is controlled by the unwinding correction device to ensure that the deviation does not exceed 3% of the diaphragm width. If this condition is not met, although the problem of creases caused by temperature difference in the diaphragm can be solved, due to the asymmetry between the left and right sides during operation and the inconsistent force on both sides, the film will jump during winding, resulting in other defects such as uneven end faces.

[0021] The diaphragm winding method described above has a single-layer thickness of 4-40 μm; the winding adopts an independent arm, shaftless, air-expansion shaft, or slip shaft winding method; and the slitting speed is ≤250 m / min.

[0022] In the diaphragm winding method described above, the proportion of temperature difference folding defects in the diaphragm roll is no higher than 0.7%, the proportion of wrinkle defects is no higher than 0.7%, the proportion of unwinding defects is no higher than 0.7%, the proportion of uneven end face defects is no higher than 0.7%, and the total defect proportion is no more than 2%.

[0023] Beneficial effects:

[0024] This invention ensures that the separator at the winding point is free from common slitting defects such as wrinkles, unwinding, and uneven end faces. It also meets the requirement that the expanding gas in the separator should be discharged from the side with a relatively large interlayer spacing during rapid heating, thus preventing the separator from creases due to internal stress. This solves the problem of separator creases caused by temperature difference without introducing new problems, and greatly reduces production costs for separator or battery manufacturers. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the spindle-shaped core structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the spindle-shaped core winding of the present invention;

[0027] Figure 3 This is a schematic diagram of the winding of a cylindrical core in the prior art;

[0028] Among them, 1-gap between layers in the middle position, 2-gap between layers on both sides. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0030] The following are the test methods for each performance aspect in the examples and comparative examples:

[0031] Percentage of defects caused by temperature difference: After placing the diaphragm roll obtained by winding in an environment of 20°C for 2 hours, it was transferred to an environment of 45°C for 0.5 hours. After taking it out, it was observed whether there were creases on the surface of the diaphragm. The number of diaphragm rolls obtained in each embodiment and comparative example was 1000. Percentage of defects caused by temperature difference = number of diaphragm rolls with creases on the surface of the diaphragm / 1000 × 100%.

[0032] The percentage of wrinkled defects is determined by real-time detection using an online defect detector installed on the slitting machine. If the online defect detector shows that a certain membrane roll has a wrinkled defect, the membrane roll is recorded as defect 1, and the number of defective membrane rolls is accumulated sequentially. The number of diaphragm rolls obtained in each embodiment and comparative example is 1000, and the percentage of wrinkled defects = number of diaphragm rolls with wrinkles / 1000 × 100%.

[0033] Defect percentage of roll unwinding: The membrane roll is placed horizontally on the inspection platform and dropped freely from a height of 500mm (with the core landing on the ground). If the membrane roll slips off the core, it is recorded as a roll unwinding defect. The number of diaphragm rolls obtained in each embodiment and comparative example is 1000. Defect percentage of roll unwinding = number of diaphragm rolls that produce roll unwinding defects / 1000 × 100%.

[0034] Percentage of end-face unevenness defects: After the membrane roll is cut, it is illuminated with a flashlight parallel to the cut end face and manually observed. If obvious misalignment is found on the end face (generally ≥2mm), the membrane roll is recorded as having an end-face unevenness defect. The number of diaphragm rolls obtained in each embodiment and comparative example is 1000. Percentage of end-face unevenness defects = number of diaphragm rolls with end-face unevenness / 1000 × 100% ≤ 0.7%.

[0035] Example 1

[0036] A method for winding a diaphragm, wherein:

[0037] The object to be wound is a single-layer polypropylene diaphragm with a thickness of 14μm, and the diaphragm roll is obtained by winding.

[0038] The winding process uses a slip-shaft winding method;

[0039] The winding uses a spindle-shaped core made of paper. The spindle-shaped core is composed of two frustums I and II of the same length, each with a hollow part inside. The hollow parts of the two frustums are coaxial. The large ends of frustums I and II are attached together and have a diameter of 153mm. The angle between the generatrix of frustum I and the central axis is 0.2°, and the angle between the generatrix of frustum II and the central axis is 0.2°. The length of frustum I is 200mm, and the length of frustum II is 200mm.

[0040] During the roll-up process, such as Figure 1 As shown, the gap 2 between the layers on both sides of the spindle-shaped core is greater than the gap between the layers in the middle position. By controlling the unwinding and correction device, the deviation between the middle position of the diaphragm roll and the intersection position of frustum I and frustum II is 1% of the diaphragm width. The slitting speed is 150m / min, the winding tension is 0.18N / mm, the winding taper is 1.5%, the width of the diaphragm roll is 350mm, and the winding length is 2000m.

[0041] The final diaphragm roll had a wrinkle defect rate of 0.2%, an uneven end face defect rate of 0.3%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 0.8%, and a total defect rate of 1.3%.

[0042] Comparative Example 1

[0043] A method for winding a diaphragm is basically the same as in Example 1, except that the core is a hollow cylinder with an outer diameter the same as the large end diameter of the frustum I in Example 1 and a length the same as the spindle-shaped core in Example 1.

[0044] The final diaphragm roll had a wrinkle defect rate of 0.2%, an uneven end face defect rate of 0.3%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 6.1%, and a total defect rate of 6.6%.

[0045] Comparing Comparative Example 1 and Example 1, it can be seen that the core in Comparative Example 1 is a hollow cylinder, such as... Figure 3 As shown, this leads to a significant increase in the proportion of defects caused by temperature difference folding. This is because when a hollow cylindrical core is used for winding, the gaps between layers in the middle position (1) and between layers on both sides (2) of the diaphragm roll are basically the same. After the diaphragm is heated, the gas will expand rapidly. The expanded gas cannot be quickly discharged from the roll, which causes the internal stress of the roll to increase rapidly and produce folds.

[0046] Comparative Example 2

[0047] A method for winding a diaphragm is basically the same as in Example 1, except that the angle between the generatrix of frustum I and the central axis is 0.1°, and the angle between the generatrix of frustum II and the central axis is 0.1°.

[0048] The final diaphragm roll had a wrinkle defect rate of 0.2%, an uneven end face defect rate of 0.3%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 3.2%, and a total defect rate of 3.7%.

[0049] Comparing Comparative Example 2 and Example 1, it can be seen that in Comparative Example 2, the angle between the generatrices of frustum I and frustum II and the central axis is too small, which leads to a significant increase in the proportion of thermal folding defects. This is because when the angle between the generatrices of frustum I and frustum II and the central axis is too small, such as... Figure 2 As shown, although there are differences between the gaps 1 between the layers in the middle position and the gaps 2 between the layers on both sides of the diaphragm roll, the differences are not significant. The resulting gaps are insufficient to allow the gas with a larger coefficient of thermal expansion to escape quickly. Although this is an improvement over the hollow cylindrical core, the effect is still not ideal.

[0050] Comparative Example 3

[0051] A method for winding a diaphragm is basically the same as in Example 1, except that the angle between the generatrix of frustum I and the central axis is 0.5°, and the angle between the generatrix of frustum II and the central axis is 0.5°.

[0052] The final diaphragm roll had a wrinkle defect rate of 2.2%, an uneven end face defect rate of 0.3%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 0%, and a total defect rate of 2.5%.

[0053] Comparing Comparative Example 3 with Example 1, it can be seen that the angle between the generatrix of frustum I and frustum II in Comparative Example 3 and the central axis is too large, which will lead to an increase in the proportion of wrinkle defects. This is because the angle between the generatrix of frustum I and frustum II and the central axis is too large, and the difference between the diameters at both ends of frustum I and frustum II is too large. During the winding process, the diaphragm is subjected to inconsistent forces, resulting in an increase in the proportion of wrinkle defects.

[0054] Example 2

[0055] A method for winding a diaphragm is basically the same as in Example 1, except that the winding object is a polyethylene diaphragm, the angle between the generatrix of frustum I and the central axis is 0.3°, and the angle between the generatrix of frustum II and the central axis is 0.3°.

[0056] The final diaphragm roll had a wrinkle defect rate of 0.3%, an uneven end face defect rate of 0.3%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 0%, and a total defect rate of 0.6%.

[0057] Comparative Example 4

[0058] A method for winding a diaphragm is basically the same as in Example 2, except that the winding tension is 0.04 N / mm.

[0059] The final diaphragm roll had a wrinkle defect rate of 0.8%, an uneven end face defect rate of 1.3%, a roll unwinding defect rate of 1.4%, a temperature difference folding defect rate of 0%, and a total defect rate of 3.5%.

[0060] Comparing Comparative Example 4 and Example 2, it can be seen that the insufficient winding tension in Comparative Example 4 leads to an increase in defects such as wrinkles, uneven end faces, and roll-out. This is because insufficient winding tension reduces the stress on the diaphragm during production, making it prone to wrinkles. During winding, if the winding tension is too low, the friction between the layers of the diaphragm roll is too small, causing it to easily move left and right, resulting in uneven end faces. After being wound onto the diaphragm roll, the low friction makes it easy for the entire roll to slip off, resulting in roll-out defects.

[0061] Comparative Example 5

[0062] A method for winding a diaphragm is basically the same as in Example 2, except that the winding tension is 0.32 N / mm.

[0063] The final diaphragm roll had a wrinkle defect rate of 1.4%, an uneven end face defect rate of 0.1%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 1.3%, and a total defect rate of 2.8%.

[0064] Comparing Comparative Example 5 and Example 2, it can be seen that excessive winding tension in Comparative Example 5 leads to an increase in the proportion of wrinkles and temperature difference folding defects. This is because excessive winding tension makes the diaphragm prone to deformation and wrinkling defects during the winding process. After being wound onto the diaphragm roll, the gas channels are blocked due to the excessive tightness between the layers, making it difficult to expel gas quickly, thus increasing the proportion of temperature difference folding defects.

[0065] Comparative Example 6

[0066] A method for winding a diaphragm is basically the same as in Example 2, except that the winding taper is 0.5%.

[0067] The final diaphragm roll had a wrinkle defect rate of 0.8%, an uneven end face defect rate of 0.2%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 0.7%, and a total defect rate of 1.7%.

[0068] Comparing Comparative Example 6 and Example 2, it can be seen that the winding taper in Comparative Example 6 is too small, which leads to an increase in the proportion of wrinkles and temperature difference crease defects. This is because the winding taper is too small, resulting in insufficient tension attenuation during winding, which makes the overall winding tension too large, thus increasing the proportion of wrinkles during winding. After being wound onto the diaphragm roll, the winding taper is too small, making it too tight and preventing the rapidly expanding gas from escaping, thus increasing the proportion of temperature difference crease defects.

[0069] Comparative Example 7

[0070] A method for winding a diaphragm is basically the same as in Example 2, except that the winding taper is 0.4%.

[0071] The final diaphragm roll had a wrinkle defect rate of 1.0%, an uneven end face defect rate of 0.2%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 0.9%, and a total defect rate of 2.1%.

[0072] Comparing Comparative Example 7 and Example 2, it can be seen that the winding taper in Comparative Example 7 is too small, which leads to an increase in the proportion of wrinkles and temperature difference crease defects. This is because the winding taper is too small, and the tension decay is insufficient during the winding process, resulting in excessive overall winding tension and an increase in the proportion of wrinkles during the winding process. After being wound onto the diaphragm roll, the winding is too tight due to the small winding taper, and the rapidly expanding gas is not easy to escape, resulting in an increase in the proportion of temperature difference crease defects.

[0073] Comparative Example 8

[0074] A method for winding a diaphragm is basically the same as in Example 2, except that the winding taper is 3.5%.

[0075] The final diaphragm roll had a wrinkle defect rate of 0.3%, an uneven end face defect rate of 1.2%, a roll unwinding defect rate of 1.1%, a temperature difference folding defect rate of 0%, and a total defect rate of 2.6%.

[0076] Comparing Comparative Example 8 and Example 2, it can be seen that the excessively large winding taper in Comparative Example 8 leads to an increase in the proportion of uneven end faces and unwinding defects. This is because an excessively large winding taper causes the tension to decay too quickly during the winding process, resulting in a lower overall winding tension. During the winding process, the friction between the layers of the diaphragm roll decreases, causing the diaphragm to move left and right, resulting in uneven end faces. After being wound onto the diaphragm roll, the low winding tension and loose winding can easily lead to unwinding defects.

[0077] Comparative Example 9

[0078] A method for winding a diaphragm is basically the same as in Example 2, except that the width of the diaphragm roll is 1200 mm.

[0079] The final diaphragm roll had a wrinkle defect rate of 1.0%, an uneven end face defect rate of 0.6%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 1.2%, and a total defect rate of 2.8%.

[0080] Comparing Comparative Example 9 and Example 2, it can be seen that the excessive width of the diaphragm roll in Comparative Example 9 leads to an increase in the proportion of defects such as winding wrinkles, uneven end faces, and temperature difference folding. This is because the excessive width of the diaphragm roll results in a large difference in the diameters of the two ends of frustum I and frustum II, leading to excessive stress differences on the diaphragm during winding, which in turn increases the proportion of defects such as wrinkles and uneven end faces. Furthermore, the excessive width of the diaphragm roll results in excessive resistance to the discharge of gas after rapid expansion due to heating, which hinders the rapid discharge of gas and leads to an increase in the proportion of defects caused by temperature difference folding.

[0081] Example 3

[0082] A method for winding a diaphragm is basically the same as in Example 2, except that the winding object is a polypropylene / polyethylene composite diaphragm, the angle between the generatrix of truncated cone I and the central axis is 0.4°, and the angle between the generatrix of truncated cone II and the central axis is 0.4°.

[0083] The final diaphragm roll had a wrinkle defect rate of 0.7%, an uneven end face defect rate of 0.3%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 0%, and a total defect rate of 1%.

[0084] Example 4

[0085] A method for winding a diaphragm, wherein:

[0086] The object to be wound is a single-layer polyethylene diaphragm with a thickness of 14μm, and the diaphragm roll is obtained by winding.

[0087] The winding process uses a slip-shaft winding method;

[0088] The winding uses a spindle-shaped core made of paper. The spindle-shaped core is composed of two frustums I and II of the same length, each with a hollow part inside. The hollow parts of the two frustums are coaxial. The large ends of frustums I and II are attached together and have a diameter of 153mm. The angle between the generatrix of frustum I and the central axis is 0.3°, and the angle between the generatrix of frustum II and the central axis is 0.3°. The length of frustum I is 275mm, and the length of frustum II is 275mm.

[0089] During the winding process, the unwinding correction device controls the deviation of the middle position of the diaphragm roll from the intersection position of frustum I and frustum II to 1% of the diaphragm width. The slitting speed is 150m / min, the winding tension is 0.18N / mm, the winding taper is 1.5%, the width of the diaphragm roll is 500mm, and the winding length is 5000m.

[0090] The final diaphragm roll had a wrinkle defect rate of 0.5%, an uneven end face defect rate of 0.3%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 0.6%, and a total defect rate of 1.4%.

[0091] Comparative Example 10

[0092] A method for winding a diaphragm is basically the same as in Example 4, except that the winding length is 7000m.

[0093] The final diaphragm roll had a wrinkle defect rate of 0.5%, an uneven end face defect rate of 0.3%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 1.3%, and a total defect rate of 2.1%.

[0094] Comparing Comparative Example 10 and Example 4, it can be seen that excessive winding in Comparative Example 10 leads to an increase in the proportion of temperature difference folding defects. This is because when the winding length is too long, the overall shrinkage of the diaphragm is too large, which will cause the inside of the membrane roll to be too tight, affecting the venting effect and thus increasing the proportion of temperature difference folding defects.

[0095] Example 5

[0096] A method for winding a diaphragm is basically the same as in Example 4, except that the winding object is a polypropylene diaphragm and the winding length is 3000m.

[0097] The final diaphragm roll had a wrinkle defect rate of 0.5%, an uneven end face defect rate of 0.3%, a roll unwinding defect rate of 0%, a temperature difference folding defect rate of 0.3%, and a total defect rate of 1.1%.

[0098] Examples 6-38

[0099] A method for winding a diaphragm is basically the same as in Example 5, except that the winding method and / or some parameter values ​​are different.

[0100] Specific information for Examples 6 to 38 is shown in Table 1.

[0101] Table 1

[0102]

[0103]

Claims

1. A method for winding a diaphragm, characterized in that, The diaphragm is wound onto a spindle-shaped core to achieve diaphragm winding, resulting in a diaphragm roll. The spindle-shaped core consists of coaxial frustum I and frustum II, with their large ends touching and having the same diameter. The angle between the generatrix of frustum I and the central axis is 0.2-0.4°, and the angle between the generatrix of frustum II and the central axis is also 0.2-0.4°. The winding tension is 0.05-0.30 N / mm; the winding taper is 0.6-3%; the width of the diaphragm roll is 50-1000 mm; and the winding length is ≤5000 m. The angle between the generatrix of frustum I and the central axis is the same as the angle between the generatrix of frustum II and the central axis. Frustum I and Frustum II have the same length.

2. The method for winding a diaphragm according to claim 1, characterized in that, The large end diameter of frustum I is 76.5-204 mm.

3. The method for winding a diaphragm according to claim 1, characterized in that, Both frustum I and frustum II have hollow interiors, and these hollow interiors are coaxial.

4. The method for winding a diaphragm according to claim 1, characterized in that, The length of the spindle-shaped core is 55-1050mm.

5. The method for winding a diaphragm according to claim 4, characterized in that, The length of the spindle-shaped core is 55-600mm.

6. The method for winding a diaphragm according to claim 1, characterized in that, The winding tension is 0.14-0.25 N / mm; the winding taper is 1.0-2.0%; and the width of the diaphragm roll is 50-600 mm.

7. The method for winding a diaphragm according to claim 1, characterized in that, During the winding process, the unwinding and correction device controls the deviation of the middle position of the diaphragm roll from the intersection position of frustum I and frustum II to no more than 3% of the diaphragm width.

8. The method for winding a diaphragm according to claim 1, characterized in that, The thickness of a single layer of the diaphragm is 4-40μm; the winding method adopts independent arm, shaftless, air expansion shaft or slip shaft winding method; the slitting speed is ≤250m / min.

Images