A method of preparing a metal-faced acoustic liner

Abstract

The application discloses a preparation method of a metal panel acoustic lining and belongs to the technical field of aviation material forming. The method comprises the following steps: preparing a hole blocking plate, preparing a co-bonding metal perforated plate, and gluing to form a metal panel acoustic lining. The application blocks the hole positions on the metal perforated plate by preparing the hole blocking plate on the metal perforated plate. After the hole positions on the metal perforated plate are blocked, the adhesive is applied to the gluing surface of the metal perforated plate, so that the adhesive is effectively prevented from flowing into the hole positions during the application process. After the adhesive is dried, the hole blocking plate is removed. Since the adhesive located at the hole positions of the metal perforated plate is connected with the hole blocking plate, the adhesive located at the hole positions of the metal perforated plate is removed at the same time when the hole blocking plate is removed. The adhesive is effectively prevented from being blocked in the hole positions of the perforated plate during gluing and solidification. The gluing blocking rate of the acoustic lining part is reduced, the yield of the part is improved, and the production cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of aerospace material forming technology, and specifically relates to a method for preparing a metal panel acoustic liner. Background Technology

[0002] With the rapid development of civil aviation, noise issues have received increasing attention, and noise standards for civil aircraft have become increasingly stringent. Aircraft noise levels are a crucial component of airworthiness certification. Engine noise is one of the main sources of aircraft noise, comprising wheel machinery noise, jet noise, combustion noise, fan noise, and compressor noise. These noises affect passengers and pilots. In engine noise control, acoustic liner is an effective noise reduction method.

[0003] Considering that adhesives can clog the through-holes of the perforated panel during the curing process of the acoustic liner components, film-type adhesives with poor flowability are generally used to bond the perforated panel to the honeycomb core. However, using film-type adhesives to bond the metal perforated panel to the honeycomb core requires anodizing of the bonding surface of the metal perforated panel, which is not only inefficient but also increases costs. Using liquid adhesives to bond the metal perforated panel and the honeycomb core eliminates the need for special treatment of the metal perforated panel. Therefore, after ensuring the liquid adhesive is applied evenly, removing the adhesive from the holes is a problem that needs to be solved for the sound-absorbing and noise-reducing liner components of the honeycomb sandwich metal panel. Summary of the Invention

[0004] Objective of the invention: To provide a method for preparing a metal panel acoustic liner, which solves the above-mentioned problems existing in the prior art.

[0005] Technical solution: A method for preparing a metal panel acoustic liner, comprising the following steps:

[0006] A. Preparation of the plugging plate:

[0007] Cut out rubber of the same size as the perforated panel, apply release agent to it and let it dry to obtain brush film rubber. Apply release agent to the non-adhesive side of the metal perforated panel and let it dry to obtain brush film panel. Lay the brush film panel and brush film rubber in sequence on the flat fixture, seal it, vacuum it and put it in a hot autoclave for pre-pressing to form a hole-blocking plate on the metal perforated panel. The non-adhesive side of the brush film panel is in contact with the brush film rubber.

[0008] B. Preparation of co-bonded metal perforated plates

[0009] Grind the metal perforated panel adhesive surface on the plugging plate in A. After grinding, a ground surface is obtained. After cleaning and drying, apply adhesive to the ground surface. Let it stand in a constant temperature environment to allow the adhesive to dry and form an adhesive surface. Remove the plugging plate and take out the adhesive at the metal perforation hole to obtain a co-adhesive metal perforated plate with an adhesive surface.

[0010] C. Adhesive bonding:

[0011] The honeycomb core with the backing plate is placed on a flat fixture. The co-adhesive metal perforated plate in B is placed on the honeycomb core, and then vacuum-sealed and thermo-pressed to obtain a metal panel acoustic liner. The adhesive surface is located between the co-adhesive metal perforated plate and the honeycomb core contact surface.

[0012] Preferably, in step A, the rubber is multilayer silicone rubber with a thickness of 2-4 mm.

[0013] Preferably, in step A, the autoclave is used for hot pressing at a temperature of 140-190℃ and a pressure of 0.27Mpa~0.65Mpa for at least 60 minutes.

[0014] Preferably, in step B, the perforated metal panel is polished using a pneumatic polisher to a minimum of 150 grit until the polished surface is uniform.

[0015] Preferably, in step B, the object is left to stand in a constant temperature environment of 18-26℃ for 30-35 minutes.

[0016] Preferably, in step B, the adhesive is a liquid adhesive. Preferably, in step B, the plugging plate is removed by tearing it off in one direction at once, first pulling it upwards, and then pulling it at a constant speed along the length or width of the metal plate, to avoid the rubber at the hole being broken and left in the hole due to the lateral pressure of the metal plate hole.

[0017] Preferably, in step C, the hot-pressing conditions are: curing temperature 82-93℃, holding time 120-130min, and pressure of 0.5-0.1MPa.

[0018] Preferably, in step A, the release agent is applied in at least 5 layers.

[0019] Beneficial Effects: This invention relates to a method for preparing a metal panel acoustic liner. A plugging plate is fabricated on a perforated metal plate to seal the holes in the plate. After the holes are sealed, adhesive is applied to the bonding surface of the perforated metal plate, effectively preventing the adhesive from flowing into the holes during application. After the adhesive dries, the plugging plate is removed. Since the adhesive at the holes in the perforated metal plate is connected to the plugging plate, removing the plugging plate removes the adhesive at the holes simultaneously, effectively preventing the adhesive from clogging the holes during bonding and curing. This not only reduces the bonding blockage rate of the acoustic liner parts and increases the yield of finished parts, but also reduces production costs. Attached Figure Description

[0020] Figure 1This is a process flow diagram of the present invention;

[0021] Figure 2 This is a diagram of the encapsulation structure of the hole-plugging plate of the present invention;

[0022] Figure 3 This is a structural diagram of the adhesive encapsulation of the present invention.

[0023] Figures 2 to 3 The reference numerals in the attached diagram are as follows: 1. Brush film rubber; 2. Brush film panel; 3. Hole position; 4. Encapsulation; 5. Honeycomb core; 6. Co-adhesive metal perforated plate; 7. Adhesive surface; 8. Flat panel tooling. Detailed Implementation

[0024] like Figures 1 to 3 As shown, a method for preparing a metal panel acoustic liner includes the following steps:

[0025] A. Preparation of the plugging plate:

[0026] Cut rubber to the same size as the perforated metal plate. In this embodiment, the rubber is a two-layer silicone rubber with a thickness of 2-4 mm. After the rubber is cut, apply a release agent to it. Apply at least 5 layers of release agent to prevent the rubber and the perforated metal plate from hardening and sticking together when the rubber is removed. After the release agent dries, brush film rubber 1 is obtained. Apply release agent to the non-adhesive surface of the perforated metal plate. After the release agent dries, brush film panel 2 is obtained. After brush film panel 2 and brush film rubber 1 are sequentially laid on the flat fixture 8, they are encapsulated 4, vacuumed and placed in a hot autoclave for pre-pressing to form a hole-blocking plate on the perforated metal plate. The encapsulation 4 can be performed using materials such as a release film, breathable felt, or vacuum bag. When brush film panel 2 and brush film rubber 1 are laid sequentially, the non-adhesive surface of the brush film panel is in contact with the brush film rubber 1.

[0027] B. Preparation of co-bonded metal perforated plates 6

[0028] The metal perforated panel adhesive surface of the plugging plate in section A is ground. After grinding, a ground surface is obtained. After grinding, the grinding surface is cleaned with acetone. After cleaning, it is dried using a drying device. Then, adhesive is applied to the ground surface. The adhesive is a liquid adhesive. It is left to stand for 30-35 minutes in a constant temperature environment of 18-26℃ to allow the adhesive to dry and form an adhesive surface 7. Then, the plugging plate is removed. If a solid adhesive is used, due to the viscosity of the adhesive, the adhesive at the edge of the hole will be pulled away when the plugging plate is removed, resulting in no adhesive at the edge of the hole. To avoid the above problems, in this embodiment, liquid adhesive is used. Therefore, during the removal of the plugging plate, only the adhesive inside the hole is removed, and the adhesive around the hole is not affected. The plugging plate can be removed by tearing it off in one direction at once. In order to remove the plugging plate smoothly, the operator first lifts the plugging plate upward. After lifting it partially, the operator then pulls it at a constant speed along the length or width of the metal perforated plate at an angle until the plugging plate is removed from the metal perforated plate. During the removal of the plugging plate, since the plugging plate is partially located inside the hole 3 of the metal perforated plate, the adhesive at the hole 3 of the metal perforated plate can be removed at the same time as the plugging plate is removed, resulting in a co-adhesive metal perforated plate 6 with an adhesive surface 7.

[0029] C. Adhesive bonding:

[0030] The honeycomb core 5 with the backing plate bonded is placed on the flat fixture 8. The co-bonded metal perforated plate 6 prepared in step B is placed on the honeycomb core 5 and then vacuum-sealed 4. The curing temperature is 82-93℃, the pressure is 0.5~0.1MPa, and the hot pressing is carried out for 120-130 minutes to form a metal panel sound liner. The adhesive surface 7 is located between the contact surface of the co-bonded metal perforated plate 6 and the honeycomb core 5.

[0031] By using a plugging plate on the non-adhesive surface of the perforated metal plate to seal the hole 3 of the metal hole position 3 plate, and then applying adhesive to the adhesive surface of the metal hole position 3 plate, the adhesive at the hole 3 of the metal hole position 3 plate comes into contact with the plugging plate at the hole 3 of the metal hole position 3 plate. After the adhesive dries, when the plugging plate is removed, the adhesive at the hole 3 of the metal hole position 3 plate is removed along with the plugging plate, effectively preventing the hole 3 of the metal hole plate from being blocked by the adhesive. This ensures that the high perforation rate of the metal hole position 3 plate does not affect the bonding strength of the metal panel sound liner. At the same time, since the plugging plate is made of rubber by hot pressing, the manufacturing process is not only simple, but the rubber cost is also low. Using this method, production costs are reduced while ensuring the quality of the parts.

[0032] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the protection scope of the present invention.

Claims

1. A method for preparing a metal panel acoustic liner, characterized in that, Includes the following steps: A. Preparation of the plugging plate: Cut out rubber with the same size as the perforated panel, apply release agent to it and let it dry to obtain brush film rubber (1), apply release agent to the non-adhesive surface of the metal perforated panel and let it dry to obtain brush film panel (2), put brush film panel (2) and brush film rubber (1) on the flat fixture (8) in sequence, encapsulate it (4), vacuum it and put it into the autoclave for pre-pressing to form a hole-blocking plate on the metal perforated panel, wherein the non-adhesive surface of the brush film panel is in contact with the brush film rubber (1); B. Preparation of co-adhesive metal perforated plates (6) Grind the metal perforated panel adhesive surface on the plugging plate in A. After grinding, a ground surface is obtained. After cleaning and drying, an adhesive is applied to the ground surface. The adhesive is a liquid adhesive. After standing in a constant temperature environment to allow the adhesive to dry, an adhesive surface (7) is formed. The plugging plate is removed in one direction at once. First, pull it upward, then pull it at a constant speed along the length or width of the metal plate so that the adhesive at the metal perforation hole (3) is removed synchronously with the plugging plate, and a co-adhesive metal perforated plate (6) with an adhesive surface (7) is obtained. C. Adhesive bonding: The honeycomb core (5) with the backing plate is placed on the flat fixture (8). The co-adhesive metal perforated plate (6) in B is placed on the honeycomb core (5). The honeycomb core (5) is vacuum sealed (4) and hot-pressed to obtain the metal panel acoustic liner. The adhesive surface (7) is located between the co-adhesive metal perforated plate (6) and the honeycomb core (5).

2. The method for preparing a metal panel acoustic liner according to claim 1, characterized in that, In step A, the rubber used is multilayer silicone rubber with a thickness of 2-4 mm.

3. The method for preparing a metal panel acoustic liner according to claim 1, characterized in that, In step A, the autoclave is used for hot pressing at a temperature of 140-190℃ and a pressure of 0.27Mpa~0.65Mpa for at least 60 minutes.

4. The method for preparing a metal panel acoustic liner according to claim 1, characterized in that, In step B, the perforated metal panel is polished using a pneumatic polisher to a minimum of 150 grit until the polished surface is uniform.

5. The method for preparing a metal panel acoustic liner according to claim 1, characterized in that, In step B, the mixture is left to stand in a constant temperature environment of 18-26℃ for 30-35 minutes.

6. The method for preparing a metal panel acoustic liner according to claim 1, characterized in that, In step C, the hot-pressing conditions are: curing temperature 82-93℃, holding time 120-130min, and pressure of 0.5-0.1MPa.

7. The method for preparing a metal panel acoustic liner according to claim 1, characterized in that, In step A, the release agent should be applied in at least 5 layers.

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