Reusable septum winding core

Abstract

The utility model discloses a kind of reusable diaphragm winding roll core, belong to diaphragm production equipment technical field.The roll core includes a hard core and the elastic recovery layer of cladding in the hard core outer peripheral surface;The outer peripheral surface of the hard core is provided with a plurality of grooves;The elastic recovery layer is made of the elastic foaming material containing multiple closed bubbles in inside.Diaphragm winding, elastic recovery layer is pressed and occurs elastic deformation, its deformation portion can be contained in the groove on the surface of hard core, to effectively absorb and release diaphragm internal stress, reduce diaphragm defect, and keep the good cylindricity of roll core;When pressure removes, due to the elastic recovery effect of closed bubble, elastic recovery layer can recover to its original shape, so that roll core realizes repeated use.The utility model structure is ingenious, can improve diaphragm product quality, and significantly reduce production cost.

Description

Technical Field

[0001] This utility model relates to the field of diaphragm production equipment technology, specifically to a reusable diaphragm winding core. Background Technology

[0002] In the manufacturing process of lithium-ion batteries and other products, the separator is a critical component, and its quality directly affects the final performance and safety of the product. After production and slitting, the separator needs to be wound up using a core roll for subsequent transportation, storage, and processing. However, during the stretching and winding process, certain stresses are generated within the separator material, and the separator itself may have uneven thickness. If the core roll cannot effectively adapt to these stress changes and thickness differences, when the stress within the separator is released or when the ambient temperature and humidity change, defects such as wrinkles, bulging, edge collapse, and tire marks can easily occur in the wound separator. This seriously affects the separator's pass rate and performance, and may even lead to battery safety issues.

[0003] Currently, rigid cores, such as paper or plastic cores, are commonly used for diaphragm winding. These cores themselves undergo almost no deformation, making it difficult to effectively absorb the internal stress of the diaphragm, leading to the frequent occurrence of the aforementioned defects. To address this issue, some improvements involve wrapping a cushioning material around the rigid core. For example, utility model CN207175089U discloses a core for winding diaphragms, which has a cushioning layer on its outer periphery, and this cushioning layer contains a specific arrangement of holes. The purpose of these holes is to increase the shrinkage space of the cushioning layer, thereby absorbing diaphragm deformation. While this porous cushioning layer improves stress absorption to some extent, it essentially utilizes the relatively large pre-set cavities within the cushioning material. If the pores of such cushioning materials (such as ordinary foam) are interconnected or semi-interconnected (e.g., Figure 2 As shown in the diagram, the existing ordinary foam material structure may experience a decline in its structure and elastic recovery ability after repeated compression. Gas may partially escape or the pore walls may undergo permanent deformation, resulting in a decrease in the cylindricity of the core and making it difficult to achieve ideal, long-term reuse. Consequently, the overall cost of using the core remains high. Furthermore, if the rebound characteristics of the buffer layer are poor, it is impossible to guarantee that the initial state of the core is consistent with each use, which may affect the winding quality of subsequent batches of diaphragms.

[0004] Therefore, how to provide a diaphragm winding core that can effectively buffer the internal stress of the diaphragm, ensure the winding quality of the diaphragm, and have excellent shape recovery ability so that it can be reused multiple times and effectively reduce production costs has become a technical problem that urgently needs to be solved in this field. Utility Model Content

[0005] The purpose of this invention is to address the problems existing in the background art by providing a reusable diaphragm winding core. Through specific structural design and material selection, it aims to effectively absorb diaphragm winding stress, reduce diaphragm defects, and ensure that the core can maintain good shape and performance after multiple uses, thereby improving product quality and reducing production costs.

[0006] This utility model provides a reusable diaphragm winding core, comprising: a rigid core with a plurality of grooves on its outer peripheral surface; and an elastic recovery layer, which covers the outer peripheral surface of the rigid core and is made of an elastic foam material containing a plurality of closed air bubbles; the elastic recovery layer undergoes elastic deformation under pressure, and its deformed portion is accommodated in the plurality of grooves, and after the pressure is removed, the elastic recovery layer can return to its original shape.

[0007] Optionally, the rigid core is a hollow cylindrical structure.

[0008] Alternatively, the rigid core may be made of paper or plastic.

[0009] Optionally, multiple grooves are distributed in a grid, stripe, or spiral pattern on the outer peripheral surface of the rigid core.

[0010] Optionally, the elastic foam material is a rubber-based foam material.

[0011] Optionally, the rubber-based foam material is selected from polymeric rubber and plastic materials or rubber composite materials and is made by foaming.

[0012] Optionally, the elastic recovery layer is fixed to the outer peripheral surface of the rigid core by an adhesive.

[0013] Based on the technical content disclosed in this utility model, the following beneficial effects are achieved:

[0014] This invention features a rigid core with multiple grooves on its outer surface, covered by an elastic recovery layer composed of an elastic foam material containing numerous closed air bubbles. When the diaphragm is wound up and pressure is applied, the elastic recovery layer undergoes elastic deformation, which is contained within the grooves on the rigid core surface. This structural design provides an effective buffer space for the release of internal stress in the diaphragm, preventing stress from directly acting on the rigid core or causing excessive pressure on the elastic layer. This helps maintain the cylindricity of the entire core under pressure, thus reducing defects such as wrinkles and bulging. More importantly, because the elastic recovery layer contains numerous closed air bubbles, these bubbles provide excellent and stable resilience after the external pressure is removed, allowing the elastic recovery layer and even the entire core to accurately return to their original shape and size. This characteristic ensures that the core can be reused multiple times without performance degradation due to material fatigue or structural collapse, as seen in some existing cores. This significantly reduces material costs in the production process, improves economic efficiency, and increases the yield rate of the finished diaphragm.

[0015] Other features and advantages of the present invention will become clear from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0017] Figure 2 This is a schematic diagram of the internal pore structure of a common foamed material in the prior art.

[0018] Figure 3 This is a schematic diagram of the closed bubble structure inside the elastic recovery layer in an embodiment of this utility model.

[0019] Figure 4 This is a partial cross-sectional schematic diagram of an embodiment of the present invention in its working state.

[0020] Explanation of reference numerals in the attached diagram: 1. Rigid core; 11. Groove; 2. Elastic recovery layer; 3. Diaphragm. Detailed Implementation

[0021] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0022] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0023] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0024] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0026] The overall concept of this utility model is to provide a composite structure diaphragm winding core, which includes a rigid core as a basic support, the outer surface of which is designed with a specific groove structure; and an elastic recovery layer wrapped around the rigid core, which is made of a special elastic foam material containing a plurality of closed air bubbles. This combination allows the elastic recovery layer to elastically deform when the core is subjected to diaphragm winding pressure, and to accommodate part of the deformation in the grooves of the rigid core, thereby effectively buffering stress; after the pressure is removed, due to the excellent resilience of the closed air bubbles, the elastic recovery layer can return to its original shape, allowing the core to be reused.

[0027] Reference Figure 1 The diagram illustrates the overall structure of one embodiment of the present invention. The reusable diaphragm winding core mainly consists of a rigid core 1 and an elastic recovery layer 2 applied to the outer peripheral surface of the rigid core 1.

[0028] The rigid core 1 is the load-bearing foundation and skeleton of the winding core, providing the necessary rigidity and structural stability to ensure that it does not undergo significant deformation during winding. For example... Figure 1 and Figure 4 As shown, the rigid core 1 can be made into a hollow cylindrical structure. This hollow design not only meets the functional requirements of the winding core but also helps to reduce the overall weight of the core and facilitates its installation and fixation on various winding equipment. The material selection for the rigid core 1 is relatively wide; it can be a material with sufficient mechanical strength. For example, high-strength kraft paper can be used to create a paper tube with the required wall thickness through multi-layer winding, sizing, and drying processes. Alternatively, engineering plastics can be used to integrally manufacture it through injection molding or extrusion molding processes. Figure 1As shown, the outer peripheral surface of the rigid core 1 has multiple grooves 11 evenly distributed or arranged according to a specific pattern. The geometry, size (depth, width), number, and arrangement of these grooves 11 on the surface of the rigid core 1 can be optimized according to specific application requirements and the characteristics of the elastic recovery layer 2 used in conjunction with it. For example, as Figure 1 and Figure 4 As shown, the grooves 11 can form a regular grid-like distribution on the outer peripheral surface of the rigid core 1, such as a square groove composed of mutually perpendicular longitudinal and circumferential grooves, or a diamond-shaped groove with oblique intersections. In other embodiments, the grooves 11 can also be multiple striped grooves arranged parallel only along the axial direction of the rigid core 1, or multiple annular striped grooves arranged parallel only along the circumferential direction of the rigid core 1, or single-headed or multi-headed spiral grooves extending continuously along the outer peripheral surface of the rigid core 1. The purpose of these grooves 11 is to provide a preset and controllable deformation-accommodating space for the elastic recovery layer 2 when it undergoes radial compression deformation under the diaphragm winding pressure, while the protrusions between the grooves can also provide a certain degree of support and restraint for the elastic recovery layer 2.

[0029] The elastic recovery layer 2 is a key component for achieving the core function of this invention (i.e., stress buffering and shape restoration). It tightly covers and fixes itself in a layered form to the outer peripheral surface of the rigid core 1, which has grooves 11. To ensure a strong bond between the elastic recovery layer 2 and the rigid core 1, preventing relative sliding, misalignment, or delamination during actual use, the two are preferably fixed together using an environmentally friendly adhesive with good bonding strength. The elastic recovery layer 2 contains a plurality of special elastic foam materials, i.e., a large number of closed-cell air bubbles. (Refer to...) Figure 3 The diagram schematically illustrates the internal microstructure of this special elastic foam material. It shows that numerous air bubbles (or pores) are closed and independent, uniformly or non-uniformly dispersed within the material matrix, forming a so-called "closed-cell structure." This is consistent with... Figure 2The internal structure of some common foamed materials (such as sponges or open-cell foams) in the prior art is fundamentally different. The latter often form an "open-cell structure" or "semi-open-cell structure" where the pores are interconnected or partially interconnected. Because the elastic recovery layer 2 of this invention adopts a closed-cell structure, when it is subjected to external pressure, the gas in each of its internal closed air bubbles is compressed, while the material matrix undergoes elastic deformation. When the external pressure is removed, because these closed air bubbles are sealed, the compressed gas inside cannot leak outward, thus generating a strong rebound force that pushes the material matrix back to its original shape. This allows the entire elastic recovery layer 2 to accurately and almost completely recover to its original shape, thickness, and volume before being compressed. In a preferred embodiment, the elastic foaming material constituting the elastic recovery layer 2 is a rubber-based foaming material. For example, specific polymer rubber-plastic materials (such as silicone rubber) or special rubber composite materials can be selected as the substrate and manufactured through precise chemical or physical foaming processes to ensure the formation of a uniform, dense, and highly closed-cell structure. These rubber-based foam materials not only have excellent elasticity and resilience, but also typically possess good wear resistance, aging resistance, oil resistance, and a wide temperature range, which can meet the stringent requirements for core performance during diaphragm production and long-term storage.

[0030] Combination Figure 4During the diaphragm winding operation, the diaphragm 3 is continuously and tightly wound around the outside of the elastic recovery layer 2. As the number of diaphragm layers wound on the core increases, the internal stress of the diaphragm itself and the constant or increasing tension applied during winding work together to exert significant radial pressure on the elastic recovery layer 2. Under this pressure, the gas inside the multiple closed air bubbles inside the elastic recovery layer 2 is compressed, causing the elastic recovery layer 2 to undergo inward elastic compression deformation. At this time, since the outer peripheral surface of the rigid core 1 has grooves 11 pre-set, when the elastic recovery layer 2 is compressed, the material corresponding to the location of the grooves 11 and the adjacent area will preferentially displace and deform into these grooves 11 with designed depth and width. In other words, the deformed part of the elastic recovery layer 2 is effectively accommodated in these grooves 11. This design avoids the problem of excessive stress concentration or uneven deformation that may occur if the surface of the rigid core is completely smooth, in which case the elastic recovery layer can only be flattened as a whole. The presence of the grooves 11 makes the overall deformation of the elastic recovery layer 2 more uniform and controllable, thereby more effectively absorbing, buffering, and redistributing the pressure and internal stress from the diaphragm 3. This significantly prevents common defects such as bulging, edge collapse, and wrinkles in the diaphragm 3 during winding and subsequent storage, ensuring the flatness and overall quality of the diaphragm after winding. At the same time, because the elastic recovery layer 2 is effectively supported by the rigid core 1 at the protrusions between the grooves 11, and its overall deformation is uniform, the entire core can maintain good cylindricity and high concentricity even when subjected to the enormous pressure of the diaphragm roll.

[0031] Once the entire roll of diaphragm 3 is wound up and removed from the core of this invention, the enormous pressure previously applied to the elastic recovery layer 2 completely disappears. Because the multiple sealed air bubbles inside the elastic recovery layer 2 are independent and closed, the compressed gas inside does not leak during pressure application. Therefore, after the external pressure is removed, these compressed gases rapidly expand, generating a strong rebound force that pushes the elastic recovery layer 2 back to its original shape, thickness, and volume before being compressed. This ensures that the cylindricity and outer diameter of the entire diaphragm winding core remain highly consistent with those before initial use or after the last use. Therefore, the diaphragm winding core of this invention can be reused repeatedly without the permanent deformation and loss of elasticity that some existing cores suffer from after one or several uses, thus significantly reducing the cost per use, saving valuable production resources, and reducing waste.

[0032] In summary, this utility model innovatively and ingeniously combines a specific groove structure design on the surface of the rigid core with an elastic recovery layer made of a special elastic foam material containing multiple closed air bubbles. This not only effectively solves the quality problem caused by the difficulty in releasing internal stress during the winding process of the diaphragm and improves the pass rate of the final product, but more importantly, it endows the core with excellent and sustainable shape recovery capabilities, enabling it to be truly reusable multiple times and for a long period of time.

[0033] Although specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A reusable diaphragm winding core, characterized in that, include: A rigid core (1) has a plurality of grooves (11) on its outer peripheral surface; as well as, Elastic recovery layer (2), which covers the outer peripheral surface of the rigid core (1) and is made of elastic foam material containing a plurality of closed air bubbles inside; The elastic recovery layer (2) undergoes elastic deformation when compressed, and its deformed portion can be accommodated in the plurality of grooves (11). After the pressure is removed, the elastic recovery layer (2) can return to its original shape.

2. The diaphragm winding core according to claim 1, characterized in that: The rigid core (1) is a hollow cylindrical structure.

3. The diaphragm winding core according to claim 1 or 2, characterized in that: The rigid core (1) is made of paper or plastic.

4. The diaphragm winding core according to claim 1, characterized in that: The plurality of grooves (11) are distributed in a grid-like, striped or spiral pattern on the outer peripheral surface of the rigid core (1).

5. The diaphragm winding core according to claim 1, characterized in that: The elastic foam material is a rubber-based foam material.

6. The diaphragm winding core according to claim 5, characterized in that: The rubber-based foamed material is selected from polymer rubber and plastic materials or rubber composite materials and is made by foaming.

7. The diaphragm winding core according to claim 1, characterized in that: The elastic recovery layer (2) is fixed to the outer peripheral surface of the rigid core (1) by an adhesive.

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