Hollow dot matrix wing rudder powder cleaning hole strippable sealing method based on plastic period resin

Abstract

The invention relates to a peelable sealing method for a hollow dot matrix wing rudder powder cleaning hole based on plastic resin, belongs to the technical field of metal additive manufacturing post-treatment, and solves the problems that in the prior art, an inner cavity is polluted, a hole structure is damaged and a blocking material is difficult to remove when the powder cleaning hole is blocked by an iron nail or a welding wire. The method comprises the following steps: covering the outer side of the powder cleaning hole with an isolating layer; mixing denture water and denture powder according to the volume ratio of (2.5: 1) to (3.5: 1), monitoring the reaction state of the denture water and the denture powder, filling and covering the powder cleaning holes in the outer side of the isolating layer when the mixed material enters a plastic period, and molding to enable the mixed material to be tightly attached to the surface of the rudder body; after the material is cured, a polymethyl methacrylate plugging block is formed, and reliable sealing is achieved. Impurities are effectively prevented from entering an inner cavity of the wing rudder in the post-treatment process, plugging materials can be conveniently and completely stripped in the follow-up process, and the structural integrity of powder clearing holes is protected.

Description

Technical Field

[0001] This invention relates to the field of metal additive manufacturing post-processing technology, and in particular to a peelable sealing method for powder removal holes in hollow lattice rudders based on plastic resin. Background Technology

[0002] As one of the mainstream technologies in metal additive manufacturing, selective laser melting (SLM) can integrally form high-performance components such as wing-shaped rudders with complex internal cavities and lattice sandwich structures, demonstrating significant advantages in the aerospace field.

[0003] When manufacturing hollow array wing rudders using this technology, dedicated powder removal holes must be designed on the rudder body to ensure that residual metal powder is completely removed after forming. After powder removal, to prevent impurities from entering the product cavity through the powder removal holes and becoming foreign matter during post-processing steps (such as support removal, sandblasting, and non-destructive testing), the powder removal holes must be effectively sealed. Currently, the common sealing method is to directly plug the holes with iron nails or aluminum alloy welding wires with a diameter similar to that of the powder removal holes.

[0004] However, this existing sealing method has significant drawbacks: First, the nails or welding wires are prone to breakage due to vibration and impact in subsequent processes, and their fragments may fall into the product's internal cavity, forming difficult-to-remove metal debris, posing a serious quality hazard; second, during insertion or subsequent processing, the hard metal plug can easily scratch or squeeze the powder cleaning hole, leading to an enlarged hole diameter or structural damage, affecting product integrity; finally, the sealing reliability of this type of sealing method is limited, and the plug itself is not easy to remove completely and conveniently. Therefore, there is an urgent need to find a sealing method that provides good sealing performance, does not damage the powder cleaning hole, and is easy to remove completely. Summary of the Invention

[0005] In view of the above analysis, the present invention aims to provide a peelable sealing method for the powder cleaning holes of hollow lattice wing rudders based on plastic resin, so as to at least solve one of the problems in the prior art that the use of iron nails or welding wire to seal the powder cleaning holes can easily cause internal cavity contamination, hole structure damage and difficulty in removing the sealing material.

[0006] On one hand, embodiments of the present invention provide a peelable sealing method for powder removal holes in hollow lattice wing rudders based on plastic resin, comprising the following steps:

[0007] S1. Cover the outside of the cleaning holes of the hollow lattice wing rudder structure after cleaning;

[0008] S2. Provide a liquid component and a powder component, and mix the dental tray liquid and dental tray powder at a volume ratio of (2.5:1) to (3.5:1) to obtain a mixed material;

[0009] S3. Monitor the reaction state of the mixed material, and when the mixed material enters the plastic stage, perform a sealing operation; the plastic stage is the stage where the viscosity of the mixed material reaches 500-5000 mPa·s and does not adhere to dry gloves;

[0010] S4. Fill and cover the outside of the isolation layer at the powder clearing hole with the mixed material in the plastic period, and shape the mixed material so that it fits tightly with the surface of the rudder body;

[0011] S5. Wait for the mixed material to cure and form a polymethyl methacrylate sealing block to complete the sealing.

[0012] Furthermore, the duration of the plasticity period is adjusted by controlling the temperature of the mixing operating environment between 18°C ​​and 25°C, and the duration of the plasticity period within the temperature range is 3-8 minutes.

[0013] Furthermore, in S4, the area of ​​the mixed material covering the powder-cleaning hole is greater than 150% of the area of ​​the powder-cleaning hole itself.

[0014] Furthermore, in S4, a portion of the mixed material is squeezed into the powder-cleaning holes during shaping, and forms a mechanically interlocking structure after curing.

[0015] Furthermore, the particle size of the dental tray powder in the powder component is 80-200 mesh.

[0016] Furthermore, the isolation layer is a polyester film or a polyacrylate pressure-sensitive adhesive layer with a thickness of less than 0.1 mm.

[0017] Furthermore, the diameter of the powder cleaning hole is 2-5 mm.

[0018] Furthermore, the method further includes a post-processing step after S5 of performing sandblasting or fluorescence detection on the rudder with the sealing block.

[0019] Furthermore, after completing the post-processing, the method also includes a sealing material removal step: using a tool to pry the sealing block from the edge, and using the isolation layer as a barrier, peeling off the sealing block as a whole.

[0020] On the other hand, the present invention proposes a wing rudder structure having a hollow lattice cavity, wherein the powder cleaning hole of the wing rudder structure is sealed by a polymethyl methacrylate sealing block, the sealing block being fitted to the contour of the rudder body surface and having an isolation layer between it and the powder cleaning hole.

[0021] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0022] 1) By using a mixture of denture liquid and denture powder in its plastic phase for sealing, this material, after curing, forms a complete and dense polymethyl methacrylate (PMMA) sealing block with excellent sealing properties, preventing impurities from entering the product's internal cavity during subsequent processes such as sandblasting and fluorescence testing. Simultaneously, the pre-covered isolation layer eliminates the possibility of the sealing material itself or its residue falling into the internal cavity during removal, thus eliminating the risk of contamination from excess material.

[0023] 2) Due to the flexibility of the sealing material during its malleable period, it can be shaped to fit tightly against the rudder surface without needing to be pressed into the powder removal holes, thus avoiding scratches on the hole walls or deformation of the hole diameter caused by metal objects blocking the holes. After curing, the sealing block is bonded to the isolation layer, and during removal, it can be completely peeled off by simply prying it from the edge. The operation is simple and ensures that the structure of the powder removal holes remains intact, facilitating subsequent use or maintenance of the product.

[0024] 3) By defining the volume ratio of denture liquid to denture powder (2.5:1 to 3.5:1) and using viscosity (500-5000 mPa·s) and the requirement of non-adhesion to dry gloves to define the plasticity period, a clear and predictable time window is provided for the sealing operation. The duration of the plasticity period (3-8 minutes) can be further adjusted by controlling the ambient temperature (18℃-25℃), making the process repeatable and operable, and ensuring the consistency and stability of the sealing quality.

[0025] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0026] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0027] Figure 1 This is a flowchart illustrating the steps of the powder-removable sealing method for the cleaning hole described in this invention.

[0028] Figure 2 This is a schematic diagram of the internal cavity structure and powder cleaning hole distribution of the wing rudder structure in an embodiment of the present invention;

[0029] Figure 3 A photograph of the actual product after the powder cleaning hole was sealed using the method of the present invention;

[0030] Figure 4 A photograph of the actual product after removing the sealing material and cleaning the powder hole.

[0031] Figure label:

[0032] 1. Wing and rudder skin; 2. Internal skeleton; 3. Cavity structure; 4. Powder cleaning holes; 5. Isolation layer; 6. Polymethyl methacrylate sealing block. Detailed Implementation

[0033] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0034] After powder removal, reliable temporary sealing of the powder removal holes in hollow lattice finned rotors formed by laser selective melting technology is crucial to ensuring the quality of subsequent processes. Existing technologies using hard metal objects for sealing can damage the product and introduce foreign matter risks. Therefore, this invention provides a peelable sealing method and corresponding product based on a plastic resin, aiming to achieve a sealing effect that is non-damaging, zero-contamination, and easy to remove.

[0035] On one hand, a specific embodiment of the present invention discloses a peelable sealing method for powder removal holes in hollow lattice wing rudders based on a plastic resin, such as... Figure 1 As shown, it includes the following steps:

[0036] S1. Cover the outside of the cleaning holes of the hollow lattice wing rudder structure after cleaning;

[0037] S2. Dental tray liquid and dental tray powder are mixed at a volume ratio of (2.5:1) to (3.5:1) to obtain a mixed material;

[0038] S3. Monitor the reaction state of the mixed material, and when the mixed material enters the plastic stage, perform a sealing operation; the plastic stage is the stage where the viscosity of the mixed material reaches 500-5000 mPa·s and does not adhere to dry gloves;

[0039] S4. Fill and cover the outside of the isolation layer at the powder clearing hole with the mixed material in the plastic period, and shape the mixed material so that it fits tightly with the surface of the rudder body;

[0040] S5. Wait for the mixed material to cure and form a polymethyl methacrylate sealing block to complete the sealing.

[0041] The dental tray liquid and powder used in this invention are dental acrylic resin materials. The dental tray liquid is mainly composed of methyl methacrylate (MMA) monomer and usually contains an accelerator (such as N,N-dimethyl-p-toluidine); the dental tray powder is mainly composed of polymethyl methacrylate (PMMA) or its copolymer powder and usually contains an initiator (such as benzoyl peroxide). After the two are mixed, their polymerization process will successively go through the wet sand stage, the thin paste stage, the fiber-adhesive stage, the plastic stage, the rubber stage, and the hardening stage. Among them, the plastic stage is the key stage for implementing this invention. At this time, the material is in the form of a paste, can be shaped, and has a surface tack so low that it does not adhere to the tool.

[0042] Specifically, the present invention can use a variety of commercially available materials of this type, such as: Type II conventional dental tray powder and matching dental tray liquid from Nissin Dental Materials Co., Ltd.; quick-setting dental tray powder and matching dental tray liquid from Shanghai Second People's Hospital Zhangjiang Biomaterials Co., Ltd.; and self-setting dental tray powder and matching dental tray liquid from Lang Dental.

[0043] It should be noted that the above list of specific models is merely an example, and any similar material that can achieve the plasticity characteristics described in this invention is applicable to this invention.

[0044] During implementation, it is essential to first ensure that the powder inside the wing rudder cavity has been completely removed, for example, by confirming through X-ray computed tomography or industrial endoscopy that there is no residual powder in the internal cavity. Subsequently, an insulating layer is applied to the outside of the powder removal holes.

[0045] It should be noted that this isolation layer plays a dual role in this invention: firstly, as a physical barrier, it completely isolates the uncured denture liquid and denture powder mixture from the product cavity during the sealing stage, preventing any possible contamination; secondly, as a sacrificial layer, it guides the peeling behavior during the removal stage through the relatively weakest interfacial bonding force between itself and the product substrate, as well as between itself and the sealing block, and is the core component for achieving peelable properties.

[0046] Next, the dental tray liquid and dental tray powder are mixed at a specific volume ratio. The volume ratio of the dental tray liquid to the dental tray powder is in the range of 2.5:1 to 3.5:1 to ensure that the ratio of monomer to polymer is within an optimal window. A ratio lower than 2.5:1 (with a relative excess of dental tray powder) will result in excessively high viscosity of the mixture, which kinetically hinders the full migration and cross-linking of monomers, causing the material to gel prematurely and significantly shortening or even eliminating the plasticity period. A ratio higher than 3.5:1 (with a relative excess of dental tray liquid) will result in excessive residual monomers in the system, which thermodynamically slows down the polymerization reaction process, not only prolonging the curing time but also causing insufficient final strength of the sealing block due to the plasticizing effect, making it difficult to withstand the impact of processes such as sandblasting.

[0047] Subsequently, the reaction state of the mixture of denture liquid and denture powder is monitored to accurately capture the plasticity stage. The plasticity stage is essentially the physical state where the material viscosity reaches 500-5000 mPa·s. In this state, the mixture possesses both plasticity and extremely low surface viscosity. In practice, this state corresponds to clear macroscopic criteria: the mixture is a non-flowing paste; when touched with a dry nitrile glove or glass rod, the material can be easily shaped, can be drawn into threads, and, crucially, does not adhere at all. This phenomenon is a key indicator that the material has reached a viscosity threshold suitable for clean peeling and has entered the plasticity operation window. Once the plasticity stage is confirmed, subsequent filling and shaping operations should be performed rapidly.

[0048] Compared with existing technologies, the sealing method provided in this embodiment utilizes the special physical properties of the plastic resin to achieve a non-impact and stress-free sealing process, avoiding damage to the powder-cleaning hole structure (such as enlarged hole diameter or thread damage) caused by sealing with hard metal objects. Simultaneously, the isolation layer ensures that the cured sealing block is not directly bonded to the product body. This guarantees sealing reliability in post-processing steps (such as sandblasting) and allows for easy and rapid peeling of the sealing block after the process is completed, using tools at the isolation layer interface, without any residue falling into the inner cavity, eliminating the risk of contamination from excess material.

[0049] Furthermore, to precisely control the occurrence and duration of the plasticity period, thereby providing a stable operating window for large-scale production, the duration of the plasticity period is adjusted by controlling the temperature of the mixing operating environment between 18°C ​​and 25°C. Within this temperature range, the duration of the plasticity period is 3-8 minutes. Ambient temperature is a key factor affecting the polymerization reaction rate; within this temperature range, the plasticity period window is stable and sufficient. For example, at 18°C, the plasticity period may last 6-8 minutes, providing ample time for sealing the porous structure of complex components; at 25°C, the plasticity period may shorten to 3-5 minutes, suitable for rapid operations, but both ensure the completion of the operation.

[0050] Furthermore, to ensure sufficient adhesion of the sealing block in subsequent processing and prevent accidental detachment due to impacts from processes such as sandblasting, in S4, the area of ​​the mixed material covering the cleaning holes is greater than 150% of the area of ​​the cleaning holes themselves. This essentially provides a safety zone for the sealing block. Even under the most demanding operating conditions, if minor damage occurs at the edge of the sealing block, its core sealing area remains intact. The quantitative requirement for the coverage area (>150%) is an empirical value derived from statistical analysis of the impact momentum and direction of the sandblasting particles, ensuring reliability.

[0051] Furthermore, in S4, a portion of the mixed material is extruded into the powder-cleaning orifice during molding, forming a mechanically interlocking structure after curing. This interlocking structure (fundamentally different from interference-pressed metal plugs) greatly enhances the sealing block's resistance to axial peeling without damaging the orifice wall. The flexibility of the material during the molding period ensures that it can only fill the microstructure of the orifice without generating assembly stress. The anchoring structure formed after curing still relies on the initial failure of the isolation layer interface for removal, thus not sacrificing peelability.

[0052] Furthermore, the particle size of the dental tray powder is 80-200 mesh. This particle size range is chosen to achieve suitable initial viscosity and final cured strength after mixing. Too fine a particle size (too high a mesh count) will result in excessive viscosity after mixing, shortening the plasticity period and making it difficult to handle; too coarse a particle size (too low a mesh count) may lead to insufficient strength or a rough surface after curing. Powder with a particle size of 80-200 mesh can mix well with the dental tray liquid to form a slurry with moderate fluidity, and ultimately cure to form a dense, high-strength sealing block.

[0053] Furthermore, the isolation layer is a polyester film or polyacrylate pressure-sensitive adhesive layer with a thickness of less than 0.1 mm. This material was chosen based on its comprehensive performance: its extremely thin thickness ensures a tight fit to the complex curved surfaces of the wing and rudder, without affecting the shape and aerodynamic performance of the sealing block; its smooth and dense surface provides an ideal separation interface for the subsequent complete peeling of the sealing block, effectively preventing strong adhesion of liquid methyl methacrylate monomer (MMA) and its cured products to its surface; its chemical inertness ensures that it does not undergo adverse reactions such as swelling or dissolution with MMA monomer and its polymer (PMMA) during the sealing and curing process, ensuring the stability and reliability of the process. In addition, this material possesses a certain mechanical strength, effectively blocking the impact of external impurities in post-processing steps.

[0054] Furthermore, the diameter of the powder-cleaning orifice is 2-5 mm. The method of this invention is particularly suitable for sealing small-diameter orifices within this size range. Figure 2As shown, in the specific structure, the powder-cleaning holes are strategically located in non-critical load-bearing areas such as the internal skeleton and rudder bottom, according to the layout of the internal cavity. Their core function is to construct a continuous powder flow channel within the cavity, ensuring that powder in all enclosed areas can be effectively guided and ultimately discharged through the main powder-cleaning hole at the rudder bottom. For holes with a diameter less than 2 mm, the inherent viscosity of the plastic material makes it difficult to flow effectively and completely fill without pressure assistance, potentially leading to incomplete sealing. For holes with a diameter greater than 5 mm, to ensure the sealing block has sufficient impact and peel strength, the amount of mixed material needs to be increased proportionally according to the hole diameter, and its coverage area must be much larger than the area of ​​the powder-cleaning hole itself to provide greater adhesion and mechanical interlocking potential. Nevertheless, the core principle of achieving peelable sealing using plastic materials, upon which this invention is based, remains fully applicable.

[0055] Furthermore, the method, after S5, also includes post-processing steps such as sandblasting or fluorescence detection of the wing rudder with the sealing block. The cured polymethyl methacrylate (PMMA) sealing block possesses excellent mechanical properties comparable to engineering plastics, capable of withstanding the high-speed impact of abrasives during sandblasting, the vibration of the support grinding process, and the fluid pressure of the permeate during fluorescence detection without cracking or loosening. Its dense cross-linked polymer structure ensures sealing performance, blocking micron-sized abrasive particles and low-surface-tension permeate, thus preventing any external impurities from entering the hollow lattice cavity through the cleaning holes during the treatment of the entire rudder surface, avoiding internal debris problems caused by improper protection of the cleaning holes.

[0056] Furthermore, after completing the post-processing steps, the method also includes a sealing material removal step: using a tool to pry the sealing block from the edge, and utilizing the isolation layer as a barrier, peeling off the sealing block as a whole. This step relies on the weak interface layer effect created by the isolation layer. Because the sealing block and the wing / rudder product substrate are physically separated by the isolation layer, only weak van der Waals forces exist between them, without forming strong chemical bonds or physical interlocking. Therefore, when a small concentrated stress is applied at the edge using a tool such as a blade, the stress rapidly expands at the weak interface, thereby achieving interface failure peeling of the sealing block, rather than material fracture. This makes the operation extremely simple and quick, ensuring that the sealing block is always removed as a complete, integral structure, avoiding the generation of plastic debris, and ultimately restoring the powder-cleaning holes to their initial state with the structure intact. Figure 4 As shown.

[0057] On the other hand, in a specific embodiment of the present invention, a wing rudder structure is disclosed, the wing rudder structure having a hollow dot matrix inner cavity, the powder cleaning hole of the wing rudder structure being sealed by a polymethyl methacrylate sealing block, the sealing block being fitted to the contour of the rudder body surface, and an isolation layer being provided between the sealing block and the powder cleaning hole.

[0058] This wing rudder structural component is a specific intermediate product formed using the aforementioned peelable sealing method. The core of the component lies in the "PMMA sealing block-isolation layer" composite sealing structure at the powder cleaning hole. This structure ensures that after undergoing a series of post-processing steps such as support grinding, sandblasting, and fluorescence detection, the hollow lattice cavity of the wing rudder structural component remains isolated from the external environment, preventing impurities from entering.

[0059] Compared to the final product state achieved through traditional sealing methods such as welding, permanent adhesive bonding, or metal press-in, the wing and rudder structural component provided in this embodiment possesses temporary sealing properties. This sealing structure ensures flawless operation during post-processing without compromising the original geometry and function of the powder removal orifice. When all post-processing steps are completed, or when internal cavity inspection and maintenance are required during subsequent service life, the composite sealing structure can be removed non-destructively through a peeling operation, restoring the powder removal orifice to its unobstructed state. This not only improves product maintainability and lifecycle management convenience but also avoids the risk of electrochemical corrosion that may arise from contact with dissimilar metals, enhancing the product's reliability in harsh environments.

[0060] In summary, this invention provides a peelable sealing method for powder removal holes in hollow lattice wing fins based on a plastic resin, and wing fin products using this method. By precisely controlling the polymerization reaction state of the methyl methacrylate mixture and introducing an isolation layer to create a weak interface effect, it successfully solves the problems of product damage, introduction of foreign matter, and difficulty in removal associated with traditional metal sealing. It achieves reliable sealing of the powder removal holes during post-processing and convenient, non-destructive peeling of the sealing structure after the process, ensuring the cleanliness and structural integrity of the internal cavity of high-value hollow lattice components. This method has outstanding practical value and promising prospects in the post-processing of additive manufacturing for precision aerospace components.

[0061] The present invention will be described in more detail below through specific embodiments. These embodiments are merely descriptions of the best implementation of the invention and do not limit the scope of the invention in any way.

[0062] Example 1

[0063] S1. Select a titanium alloy wing-rudder test piece with an integrated skin-frame-matrix structure and two 4mm diameter powder cleaning holes at the rudder base. The powder cleaning process has been completed, and X-ray inspection has confirmed that there is no residual powder in the internal cavity. A polyester film (transparent tape) with a thickness of about 0.05mm is attached to the outer surface of the powder cleaning holes as an isolation layer.

[0064] S2. At room temperature (20℃), measure 15mL of "Rijin" brand denture liquid and 5mL of "Rijin" brand Type II conventional denture powder (particle size 120 mesh) (volume ratio 3:1) into a glass beaker, and stir with a glass rod at a constant speed for 30 seconds to mix them evenly.

[0065] S3. Continuously monitor the viscosity change of the mixture using a rotational viscometer. When the viscosity of the mixture reaches approximately 1500 mPa·s, and the material is malleable and non-adhesive when touched with a dry nitrile glove, it is determined that it has entered the plastic phase. This plastic phase lasted for approximately 5 minutes at 20°C.

[0066] S4. Quickly take an appropriate amount of the plastic material, completely cover and extend it beyond the powder cleaning hole area (the coverage area is about 200% of the area of ​​the powder cleaning hole itself), and apply slight pressure by hand to shape it, so that a small amount of material is squeezed into the powder cleaning hole through the isolation layer to form a mechanical interlocking prototype, while making it fit tightly against the rudder bottom curved surface.

[0067] S5. Let it stand for 10 minutes to allow it to fully harden and form a solid PMMA sealing block. Then, perform support grinding and standard sandblasting on the rudder. After completing the above steps, inspect the sealing block for damage and ensure a complete seal (see corresponding photos). Figure 3 Finally, using a blade, pry from the edge and, taking advantage of the barrier of the insulating layer, peel off the entire sealing block. Inspect the powder cleaning holes; the hole walls are smooth, without any damage or residue (see [link to powder cleaning hole condition]). Figure 4 ).

[0068] Example 2

[0069] The only difference between this embodiment and Example 1 is that in S2, the mixing volume ratio is 12.5 mL of denture liquid and 5 mL of denture powder (volume ratio 2.5:1), and the operation is carried out at room temperature of 18°C. In S3, the plasticity period lasts for about 5 minutes (viscosity is approximately in the range of 600-4800 mPa·s). The sealing and cleaning effects are comparable to those of Example 1.

[0070] Example 3

[0071] The only difference between this embodiment and Embodiment 1 is that in S1, a 0.08mm thick polyacrylate pressure-sensitive tape is used as the isolation layer. In S2, the mixing volume ratio is 17.5mL of "Shanghai Second Medical University Zhangjiang Biomaterials" brand quick-setting denture liquid and 5mL of "Shanghai Second Medical University Zhangjiang Biomaterials" brand quick-setting denture powder (volume ratio 3.5:1). In S3, the plasticity period lasts for approximately 3 minutes. When the sealing block is removed, the tape is peeled off along with the sealing block, leaving no adhesive residue at the powder removal hole.

[0072] Example 4

[0073] The only difference between this embodiment and Embodiment 1 is that in S1, the diameter of the powder cleaning hole is 2mm. In S2, the particle size of the dental tray powder is 200 mesh. The sealing operation needs to be more precise, but it can still achieve effective sealing and complete removal in the end.

[0074] Comparative Example 1

[0075] Using existing technology: an aluminum alloy welding wire with a diameter slightly less than 3mm was directly inserted into the powder cleaning hole for sealing. After sandblasting and vibration, the welding wire loosened, and impurities entered the inner cavity through the gap. Upon removing the welding wire, slight scratches were found on the hole wall.

[0076] Comparative Example 2

[0077] The only difference between this comparative example and Example 1 is that the sealing was performed when the mixture was still in the sticky stage (too early). The material was too sticky, difficult to shape, and a large amount adhered to the gloves. The sealing shape was poor and did not fit tightly to the surface. The edges were found to be curled up before subsequent sandblasting.

[0078] Comparative Example 3

[0079] The only difference between this comparative example and Example 1 is that in S1, no isolation layer was placed over the cleaning hole; the malleable material was directly filled into the cleaning hole and shaped. After curing, the sealing block formed a strong bond with the product substrate. During removal, complete peeling was impossible. When forcefully pried open with a blade, the sealing block broke, leaving large pieces of PMMA residue blocking the cleaning hole, which was difficult to remove.

[0080] Characterization results and analysis

[0081] The characterization results of the above-described embodiments and comparative examples are shown in Table 1 below.

[0082] Table 1. Comparison of blocking effects between each embodiment and the comparative example.

[0083]

[0084] As can be seen from the characterization results in Table 1, the sealing methods provided in Examples 1-4 of the present invention perform well in all evaluation indicators: all examples maintain "complete and no detachment" seal integrity after sand blowing, the cleanliness of the inner cavity after cleaning is "no impurities entering" and the state of the powder cleaning hole is "intact and undamaged", and the operation convenience reaches the level of "acceptable" to "excellent".

[0085] In contrast, Comparative Examples 1-3 have defects in at least one aspect of sealing integrity, internal cavity cleanliness, or powder cleaning hole status, and their operational convenience is rated as "poor" or "very poor". Their overall performance is far inferior to that of the embodiments of the present invention.

[0086] In summary, by precisely controlling the material ratio and reaction state and introducing an isolation layer, this invention successfully solves the comprehensive problem of powder removal hole blockage in the post-processing of hollow lattice wing rudders, achieving excellent results of reliable sealing, convenient cleaning, and no product damage. It is particularly suitable for the manufacturing of high-value precision components in the aerospace field.

[0087] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A peelable sealing method for powder removal holes in hollow lattice wing rudders based on plastic resin, characterized in that, Includes the following steps: S1. Cover the outside of the cleaning holes of the hollow lattice wing rudder structure after cleaning; S2. Mix the dental tray liquid and dental tray powder at a volume ratio of (2.5:1) to (3.5:1) to obtain a mixed material; S3. Monitor the reaction state of the mixed material, and when the mixed material enters the plastic stage, perform a sealing operation; the plastic stage is the stage where the viscosity of the mixed material reaches 500-5000 mPa·s and does not adhere to dry gloves; S4. Fill and cover the outside of the isolation layer at the powder clearing hole with the mixed material in the plastic period, and shape the mixed material so that it fits tightly with the surface of the rudder body; S5. Wait for the mixed material to cure and form a polymethyl methacrylate sealing block to complete the sealing.

2. The method according to claim 1, characterized in that, The duration of the plasticity period is adjusted by controlling the temperature of the mixing operating environment between 18°C ​​and 25°C, and the duration of the plasticity period within the temperature range is 3-8 minutes.

3. The method according to claim 1, characterized in that, In S4, the area covered by the mixed material of the powder cleaning hole is greater than 150% of the area of ​​the powder cleaning hole itself.

4. The method according to claim 1, characterized in that, In S4, a portion of the mixed material is squeezed into the powder-cleaning holes during shaping, and forms a mechanically interlocking structure after curing.

5. The method according to claim 1, characterized in that, The particle size of the dental tray powder is 80-200 mesh.

6. The method according to claim 1, characterized in that, The isolation layer is a polyester film or a polyacrylate pressure-sensitive adhesive layer with a thickness of less than 0.1 mm.

7. The method according to claim 1, characterized in that, The diameter of the powder cleaning hole is 2-5mm.

8. The method according to claim 1, characterized in that, The method further includes a post-processing step after S5: sandblasting or fluorescence detection of the rudder with the sealing block.

9. The method according to claim 8, characterized in that, After completing the post-processing, the method further includes a sealing material removal step: using a tool to pry the sealing block from the edge, and using the isolation layer as a barrier, peeling off the sealing block as a whole.

10. A wing rudder structural component, characterized in that, The wing rudder structure has a hollow dot matrix inner cavity, and the powder cleaning hole of the wing rudder structure is sealed by a polymethyl methacrylate sealing block. The sealing block fits the contour of the rudder body surface and is provided with an isolation layer between it and the powder cleaning hole.

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