Sealant in-situ curing forming coating device and sealant coating method thereof

Abstract

The invention discloses a sealant in-situ curing forming and coating device and a sealant coating method thereof.The sealant in-situ curing forming and coating device comprises a rigid cavity base body, a rigid confinement cavity is formed in the rigid cavity base body, and a functional lining is tightly attached to the inner wall of the confinement cavity; a forming cavity penetrating through a body of the functional lining is formed in the functional lining, and a sealant flowing channel and a final forming space are formed by the forming cavity. The functional lining is used for storing and conveying an activating agent to the inner wall surface of the molding cavity so as to form a layer of uniform activating agent film and is used for triggering the colloid to be quickly cured at the contact interface of the colloid and the inner wall of the molding cavity after quantitative glue filling so as to form a sealing layer on the surface of the colloid molded by the molding cavity; the sealing layer constrains the outer contour and size of the final sealant structure. According to the automatic sealant coating device, high-quality, high-efficiency and high-stability automatic sealant coating is achieved through precise confinement forming, in-situ instant curing and reliable lossless demolding.

Description

Technical Field

[0001] This invention relates to the field of sealant coating technology, and in particular to a sealant in-situ curing and molding coating apparatus and a sealant coating method thereof. Background Technology

[0002] Precise application and rapid curing of sealants are key processes in modern precision assembly (such as electronic products, automotive parts, and medical devices). Traditional processes typically employ a two-step method: first, the sealant is applied or injected into a predetermined cavity, and then cured by heating, ultraviolet light irradiation, or waiting for natural curing. This method suffers from problems such as long waiting times, easy overflow of the sealant leading to poor morphological accuracy, and the need for additional energy or space for subsequent curing.

[0003] Existing sealant coating and curing technologies present inherent contradictions in terms of efficiency, precision, stability, and automation. Therefore, there is an urgent need for an automated production solution that can achieve high quality, high efficiency, and high stability. Summary of the Invention

[0004] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the present invention provides a sealant in-situ curing molding and coating device and a sealant coating method, which achieves high-quality, high-efficiency and high-stability automated sealant coating through precise confined molding, in-situ instantaneous curing and reliable non-destructive demolding.

[0005] Technical Solution: To achieve the above objectives, the present invention provides a sealant in-situ curing molding and coating device and a sealant coating method, comprising a rigid cavity substrate, wherein a rigid confined cavity is formed within the rigid cavity substrate, and a functional liner is tightly attached to the inner wall of the confined cavity; the functional liner has a molding cavity penetrating its body, the molding cavity constituting a sealant flow channel and a final molding space, its axial direction being consistent with the injection direction, and its cross-sectional shape matching the target cross-sectional shape of the sealant to be molded; the functional liner is used to store and transport an activator to the inner wall surface of the molding cavity to form a uniform activator film, which is used to trigger rapid curing of the sealant at the interface with the inner wall of the cavity after quantitative filling, so as to form a sealing layer on the surface of the sealant shaped by the molding cavity, the sealing layer constraining the external contour and size of the final sealant structure.

[0006] Furthermore, the functional liner includes an activator storage layer, the inner surface of which is attached to or detachably provided with a flexible isolation membrane, the isolation membrane covering the inner surface of the activator storage layer and having its edges sealed to the activator storage layer; the isolation membrane is used to provide the molding cavity with an easily demolded colloidal contact interface and to provide a permeation channel that selectively allows the activator to pass through.

[0007] Furthermore, the activator storage layer is a porous elastomer with high resilience and uniform porosity. The outer surface profile of the porous elastomer matches the inner surface profile of the confined cavity, and its inner surface profile matches the design profile of the target colloid.

[0008] Furthermore, the activator storage layer is made of polyurethane foam.

[0009] Furthermore, the original inner diameter of the molding cavity is set as the difference between the target colloid design size and the expected compression of the porous elastomer under the rated injection pressure.

[0010] Furthermore, the isolation membrane comprises a bonding layer, a control layer, and a contact layer sequentially stacked and composited from the activator storage layer outwards; the bonding layer is a rough layer or an adhesive layer, used to adhere tightly to the activator storage layer; the control layer is a microporous membrane or a hydrophilic dense membrane, used to perform selective permeation; the contact layer is an extremely smooth chemically inert coating, used to provide an easy-to-release surface.

[0011] Furthermore, when the control layer is a microporous membrane, the size of its micropores is between the size of the activator molecule / droplet and the size of the adhesive molecule / resin monomer.

[0012] Furthermore, the contact layer is selected from polytetrafluoroethylene coating or silicone coating.

[0013] Furthermore, the rigid cavity substrate is fixedly installed on the movable end of a moving mechanism. An auxiliary positioning module is provided on the rigid cavity substrate near the port of the molding cavity to monitor the relative position of the molding cavity port and the object to be coated in real time. Both the auxiliary positioning module and the moving mechanism are electrically connected to a controller.

[0014] Furthermore, a sealant application method includes the following steps:

[0015] S1. Select a porous elastomer that matches the inner surface contour of the object to be coated, and impregnate the porous elastomer with an activator until it is saturated.

[0016] S2. The isolation membrane is attached to the inner surface of the porous elastomer that has been pre-saturated with an activator to form a functional liner, and then the functional liner is installed into the confined cavity.

[0017] S3. With the auxiliary positioning module and the moving mechanism working together, the port of the molding cavity is aligned with the object to be coated and fitted in; while the axis of the rigid cavity substrate is parallel to the axis of the object to be coated, the moving mechanism drives the rigid cavity substrate to make at least one circular motion around the axis of the object to be coated, so as to use the penetrating activator to wet the surface of the coated part.

[0018] S4. The sealant is injected into the molding cavity by the injection system. When the sealant fills the molding cavity, the porous elastomer undergoes the expected compression deformation under the rated injection pressure, so that the molding cavity changes from the original structural size to the target sealant design size. At the same time, the activator is permeated from the back side of the isolation membrane to the contact interface by squeezing the porous elastomer to form the activator film. The moment the sealant comes into contact with the activator film, it triggers its rapid curing on the contact surface to form a shaped sealing layer on the outer surface of the sealant.

[0019] S5. The rigid cavity substrate is driven to be pulled out in the opposite direction along the axial direction by the moving mechanism, so that the device and the semi-formed colloid are demolded at the colloid-film interface.

[0020] S6. After demolding, the semi-molded colloid completes the remaining curing reaction under natural air drying conditions to form the final sealed colloid structure.

[0021] Beneficial effects: The sealant in-situ curing molding coating apparatus and sealant coating method of the present invention have at least the following advantages:

[0022] (1) By limiting the rigid cavity matrix and the molding cavity designed with size compensation, the precise consistency of the adhesive strip size is ensured, and the overflow of adhesive is prevented from the physical structure.

[0023] (2) The sealant is activated by the penetrating activator to solidify the interface the moment it comes into contact with the release membrane, which achieves rapid solidification and shaping of the sealant shape. It can be demolded immediately after injection and transferred to the next coating operation, which greatly shortens the production cycle.

[0024] (3) The low surface energy composite isolation film makes the cured colloid easy to demold and completely avoids the residue of sponge on the colloid surface, thus ensuring the surface quality of the product.

[0025] (4) The closed-loop control system realizes real-time monitoring and dynamic compensation of core process parameters and can predict the life of key consumables, which significantly improves the production yield and process stability.

[0026] (5) The device integrates molding, curing and monitoring functions, and the functional lining adopts a standardized and quick-replaceable design, which reduces the difficulty of operation and maintenance costs. Attached Figure Description

[0027] Figure 1 This is a schematic cross-sectional view of the overall structure according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the layered structure of the isolation membrane of the present invention. Detailed Implementation

[0029] The invention will now be further described with reference to the accompanying drawings.

[0030] As attached Figure 1-2 The aforementioned sealant in-situ curing molding coating device and sealant coating method include a rigid cavity substrate 1, which provides the final geometric accuracy benchmark and support. The rigid cavity substrate 1 has a rigid confined cavity formed inside and integrates an installation interface. Through this installation interface, the device can be connected to a multi-degree-of-freedom moving mechanism, such as a robotic arm or an industrial robot. An auxiliary positioning module 4, such as a laser positioning sensor, is also provided on the rigid cavity substrate 1 near the port of the molding cavity 3. This module is used to monitor the relative position of the port of the molding cavity 3 and the object to be coated 5 in real time during the coating alignment, ensuring accurate alignment and uniform thickness of the sealant after curing. The auxiliary positioning module 4 and the moving mechanism are both electrically connected to a controller, thereby realizing automated coating production.

[0031] The confined cavity has a functional liner 2 that is tightly attached to and detachably installed on its inner wall. The functional liner 2 has a molding cavity 3 that runs through its body. One end of the molding cavity 3 is connected to the dispensing port of the glue injection system 6, and the other end is open as a port for fitting with the object to be glued. The molding cavity 3 constitutes a sealant flow channel and a final molding space. Its axial direction is consistent with the glue injection direction, and its cross-sectional shape matches the target cross-sectional shape of the sealant to be molded.

[0032] The functional liner 2 is used to store and transport the activator to the inner wall surface of the molding cavity 3 to form a uniform activator film. After quantitative filling, it triggers the rapid curing of the colloid at the interface where it contacts the inner wall of the cavity, so as to form a sealing layer on the surface of the colloid shaped by the molding cavity 3. This sealing layer constrains the external contour and size of the final sealed colloid structure, ensuring that its morphological accuracy is not affected by gravity, overflow and other factors during the subsequent natural curing process.

[0033] The functional liner 2 includes an activator storage layer 21, which is made of a porous elastic material with high resilience and uniform porosity, preferably polyurethane foam, and is pre-saturated with activator, such as a specially formulated soap solution or a special accelerator. Both ends of the functional liner 2 are sealed with sealing rings to prevent leakage of the activator and ensure that the activator only penetrates into the inner wall of the molding cavity 3 to form a functional film that catalyzes colloidal curing.

[0034] The outer contour of the porous elastomer matches the inner contour of the confined cavity. The rigid cavity substrate 1 is made of aluminum alloy, and its internal cavity is provided with a ring of raised rigid limiting structure 11, which is used to enclose the confined cavity with the wall near the port to form the confined cavity. This can limit the maximum compression stroke of the porous elastomer under the injection pressure, thereby ensuring that the dimensions of the molded cavity 3 are constant in the working state, and further ensuring the morphological accuracy of the final sealing adhesive.

[0035] The inner surface profile of the porous elastomer matches the design profile of the target colloid. Specifically, when designing the dimensions of its inner surface profile, the sponge compression caused by the injection pressure is taken into account. Figure 1 Taking the embodiment as an example, both the confined cavity and the molding cavity 3 are cylindrical cavities, and the functional liner 2 is an annular column structure with a uniform wall thickness H.

[0036] At this point, assuming the original inner diameter of the molding cavity 3 (in its natural state without pressure) is D1 and the target colloid design size is D2, then D1 is set as the expected compression of the porous elastomer under rated injection pressure, along with D2. The difference satisfies D1=D2- .

[0037] in, =2H*ε, H=D-D1, then:

[0038]

[0039] In the formula, D is the inner diameter of the confined cavity, which can be regarded as a known fixed constant if the rigid cavity substrate 1 is not replaced; ε is the unilateral compression ratio of the sponge under the rated injection pressure, which can be obtained by experimental calibration.

[0040] For example, according to experimental calibration, the selected sponge has a single-sided compression ratio ε of 6% under an injection pressure of 0.3 MPa. The inner diameter of the confined cavity is 40 mm. If the outer diameter of the target adhesive is expected to be 20 mm, then the inner diameter of the molding cavity 3 in the design state should be set to (20-40×0.06) / (1-0.06)≈18.72 mm.

[0041] A flexible isolation membrane 22 is attached to or detachably disposed on the inner surface of the activator storage layer 21. The isolation membrane 22 covers the inner surface of the activator storage layer 21 and its edges are sealed to the activator storage layer 21. The isolation membrane 22 is used to provide the molding cavity 3 with an easy-to-demold colloidal contact interface and to provide a permeation channel that selectively allows the activator to pass through.

[0042] The isolation membrane 22 includes a bonding layer 221, a control layer 222, and a contact layer 223, which are sequentially stacked and composited from the activator storage layer 21 outwards. The bonding layer 221 is a rough layer or an adhesive layer, used to adhere tightly to the activator storage layer 21. The control layer 222 is a microporous membrane or a hydrophilic dense membrane, used to perform selective permeation. The contact layer 223 is an extremely smooth chemically inert coating, used to provide an easy demolding surface.

[0043] When the control layer 222 is a microporous membrane, its micropore size is between the size of the activator molecule / droplet and the size of the adhesive molecule / resin monomer. This allows for selective permeation of the activator molecules while preventing reverse permeation of the adhesive.

[0044] Optionally, the contact layer 223 may be a polytetrafluoroethylene coating or a silicone coating.

[0045] Preferably, the separator 22 is made of expanded polytetrafluoroethylene (ePTFE) membrane, which has a microporous structure that allows the activator to pass through while effectively blocking the adhesive. After the membrane is cut, its edges are attached to and sealed to the inner wall of the molding cavity 3 with chemically resistant double-sided adhesive tape. During assembly, the membrane-attached functional liner 2 is pressed into the cavity of the rigid cavity substrate 1 until the sponge end contacts the limiting structure 11. At this point, the size of the molding cavity 3 is precisely defined.

[0046] The sealant application method based on the above-mentioned device includes the following workflow:

[0047] S1. Select a pre-customized polyurethane foam liner (porous elastomer) that matches the inner surface contour of the object to be coated 5, and soak the foam in soapy water until saturated.

[0048] S2. The isolation film 22 is attached to the inner surface of the sponge that has been pre-saturated with an activator to form a functional liner 2, and then the functional liner is installed into the confined cavity.

[0049] S3. Through the auxiliary positioning module 4 and the moving mechanism, the port of the molding cavity 3 is aligned with the adhesive-coated object 5 and inserted. With the axis of the rigid cavity substrate 1 parallel to the axis of the adhesive-coated object 5, the moving mechanism drives the rigid cavity substrate 1 to make at least one circular motion around the axis of the adhesive-coated object 5 to squeeze the sponge so that a certain amount of soapy water penetrates. The penetrated soapy water wets the surface of the adhesive-coated part. After the adhesive is injected, the adhesive can spread more evenly on the adhesive surface and trigger rapid curing at the contact interface of the adhesive part. This achieves rapid positioning of the adhesive relative to the adhesive surface and provides a certain connection strength to ensure that it can overcome the demolding force during demolding. It also ensures that there are no gaps between the adhesive and the adhesive surface, thus ensuring its proper sealing effect.

[0050] S4. Sealant is injected into the molding cavity 3 by the injection system 6. When the molding cavity 3 is filled with the colloid, the porous elastomer undergoes the expected compression deformation under the rated injection pressure, so that the molding cavity 3 changes from the original structural size to the target colloid design size. At the same time, by squeezing the porous elastomer, the activator penetrates from the back side of the isolation membrane 22 to the contact interface to form the activator film. The moment the colloid contacts the activator film, it triggers its rapid curing on the contact surface to form a shaped sealing layer on the outer surface of the colloid.

[0051] S5. Drive the rigid cavity substrate 1 to be pulled out in the opposite direction along the axial direction by the moving mechanism, so that the device and the semi-formed colloid are demolded at the colloid-film interface.

[0052] S6. After demolding, the semi-molded colloid completes the remaining curing reaction under natural air drying conditions to form the final sealed colloid structure.

[0053] Based on the above-described sealant coating method, by rapidly forming two cured skins (inner and outer layers) after adhesive injection, the final molded structure of the adhesive is constrained. This eliminates the need to wait for the adhesive to fully cure before demolding or to transfer the coated product to other equipment for accelerated curing. Even under controlled natural weathering conditions, the subsequent curing process still ensures the final morphological accuracy and surface quality. Therefore, while ensuring final morphological accuracy and surface quality, it makes immediate demolding after adhesive injection possible, thereby accelerating the production pace of batch adhesive application and improving production efficiency.

[0054] The device in this solution also includes a closed-loop control system, which includes a sensor group, including a fiber optic grating sensor (FBG) embedded in the side wall of the rigid cavity substrate 1, a laser displacement sensor located at the demolding station, and a pressure sensor located at the dispensing valve of the dispensing system 6; it also includes a controller (PLC) for receiving signals from the sensor group and executing two-level closed-loop control logic.

[0055] The fiber optic grating sensor is used to monitor the strain signal of the curing reaction. The laser displacement sensor is used to scan the actual molded size of the colloid. This size data can be used for long-term trend analysis. If it is found that the actual molded size of the colloid slowly increases due to sponge creep, the system will prompt to replace the functional liner 2.

[0056] The two-level closed-loop control logic specifically includes:

[0057] The first-level real-time closed-loop process: The controller receives the FBG sensor signal and determines the curing trigger time. If the trigger time is later than the set value, the controller instructs the dispensing system to appropriately increase the dispensing pressure, for example, slightly increasing it from 0.3MPa to 0.32MPa, to promote activator penetration; conversely, it appropriately reduces the pressure. Based on the deviation between the measured curing trigger time and the set value, it dynamically fine-tunes the dispensing pressure to ensure the immediacy and stability of the curing reaction.

[0058] The second-level status monitoring and maintenance closed loop: The controller records data such as pressure and trigger time for each module and calculates the health index. When the index is lower than the threshold, the operation panel will issue an early warning suggesting the replacement of the functional lining, thus achieving predictive maintenance.

[0059] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the above principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A sealant in-situ curing and coating apparatus, characterized in that: It includes a rigid cavity substrate (1), in which a rigid confined cavity is formed, and a functional liner (2) is tightly attached to the inner wall of the confined cavity. The functional liner (2) has a molding cavity (3) that runs through its body. The molding cavity (3) forms a sealant flow channel and a final molding space. Its axial direction is consistent with the injection direction, and its cross-sectional shape matches the target cross-sectional shape of the sealant to be molded. The functional liner (2) is used to store and deliver activator to the inner wall surface of the molding cavity (3) to form a uniform activator film, which triggers the rapid curing of the colloid at the interface where it contacts the inner wall of the cavity after quantitative filling, so as to form a sealing layer on the surface of the colloid shaped by the molding cavity (3), which constrains the external contour and size of the final sealed colloid structure.

2. The sealant in-situ curing and coating device according to claim 1, characterized in that: The functional liner (2) includes an activator storage layer (21), and a flexible isolation membrane (22) is attached to or detachably disposed on the inner surface of the activator storage layer (21). The isolation membrane (22) covers the inner surface of the activator storage layer (21), and its edge is sealed to the activator storage layer (21). The isolation membrane (22) is used to provide an easy-to-demold colloidal contact interface for the molding cavity (3) and to provide a permeation channel that selectively allows the activator to pass through.

3. The sealant in-situ curing and coating device according to claim 2, characterized in that: The activator storage layer (21) is a porous elastomer with high resilience and uniform porosity. The outer surface profile of the porous elastomer matches the inner surface profile of the confined cavity, and its inner surface profile matches the design profile of the target colloid.

4. The sealant in-situ curing and coating device according to claim 3, characterized in that: The activator storage layer (21) is made of polyurethane foam.

5. The sealant in-situ curing and coating device according to claim 3, characterized in that: The original inner diameter of the molding cavity (3) is set as the difference between the target colloid design size and the expected compression of the porous elastomer under the rated injection pressure.

6. The sealant in-situ curing and coating device according to claim 3, characterized in that: The isolation membrane (22) includes a bonding layer (221), a control layer (222), and a contact layer (223) that are stacked and compounded from the activator storage layer (21) outwards. The bonding layer (221) is a rough layer or an adhesive layer, used to adhere tightly to the activator storage layer (21); The control layer (222) is a microporous membrane or a hydrophilic dense membrane, used for selective permeation; The contact layer (223) is an extremely smooth, chemically inert coating used to provide an easy-to-release surface.

7. The sealant in-situ curing and coating apparatus according to claim 6, characterized in that: When the control layer (222) is a microporous membrane, the size of its micropores is between the size of the activator molecule / droplet and the size of the glue molecule / resin monomer.

8. The sealant in-situ curing and coating apparatus according to claim 6, characterized in that: The contact layer (223) is selected from polytetrafluoroethylene coating or silicone coating.

9. The sealant in-situ curing and coating device according to claim 1, characterized in that: The rigid cavity substrate (1) is fixedly installed on the movable end of a moving mechanism. An auxiliary positioning module (4) is provided on the rigid cavity substrate (1) near the port of the molding cavity (3) for real-time monitoring of the relative position between the port of the molding cavity (3) and the glued object (5). The auxiliary positioning module (4) and the moving mechanism are both electrically connected to a controller.

10. A method for applying sealant based on the apparatus according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Select a porous elastomer that matches the inner surface contour of the object to be coated (5), and impregnate the porous elastomer with an activator until it is saturated. S2. The isolation membrane (22) is attached to the inner surface of the porous elastomer that has been pre-saturated with an activator to form a functional liner (2), and then the functional liner is installed into the confined cavity. S3. By cooperating with the auxiliary positioning module (4) and the moving mechanism, the port of the molding cavity (3) is aligned with the glued object (5) and fitted in; while the axis of the rigid cavity substrate (1) is parallel to the axis of the glued object (5), the moving mechanism drives the rigid cavity substrate (1) to make at least one circular motion around the axis of the glued object (5) so as to wet the surface of the glued part with the penetrating activator. S4. The sealant is injected into the molding cavity (3) by the injection system (6). When the sealant fills the molding cavity (3), the porous elastomer undergoes the expected compression deformation under the rated injection pressure, so that the molding cavity (3) changes from the original structural size to the target sealant design size. At the same time, the activator is made to penetrate from the back side of the isolation membrane (22) to the contact interface to form the activator film by squeezing the porous elastomer. The moment the sealant contacts the activator film, it triggers its rapid curing on the contact surface to form a shaped sealing layer on the outer surface of the sealant. S5. Drive the rigid cavity substrate (1) to be pulled out in the opposite direction along the axial direction by the moving mechanism, so that the device and the semi-formed colloid are demolded at the colloid-film interface. S6. After demolding, the semi-molded colloid completes the remaining curing reaction under natural air drying conditions to form the final sealed colloid structure.

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