Method for forming hat stringer co-bonded panels

Abstract

The application discloses a hat-shaped stringer co-bonding wallboard forming method and relates to the technical field of material forming. The forming method comprises the following steps: laying a wet skin on a carrier, arranging a solidified hat-shaped stringer on the wet skin; obtaining a glass fiber gasket, covering opposite surfaces of the glass fiber gasket with dry peelable cloth, and arranging the glass fiber gasket on the wet skin at one end of the hat-shaped stringer; performing bagging by using a vacuum bag film laid outside the wet skin, the hat-shaped stringer and the glass fiber gasket and a tubular vacuum bag inserted into the hat-shaped stringer; and performing vacuumizing and hot-pressing curing. The glass fiber gasket is arranged on the wet skin at one end of the hat-shaped stringer, so that the wet skin at the position can be stressed more uniformly, and gaps existing at the joint of the tubular vacuum bag, the vacuum bag film outside and the wet skin are avoided, so that the wet skin at the corresponding position lacks pressure and appears convex wrinkles.

Description

Technical Field

[0001] This application relates to the field of material forming technology, and more specifically, to a method for forming a cap-shaped stringer co-bonded wall panel. Background Technology

[0002] The cap-shaped stringer co-bonded wall panel widely adopts the method of bonding and sealing the inner tubular vacuum bag and outer vacuum bag film of the cap-shaped stringer with sealing strips. Due to the certain thickness of the cap-shaped stringer, there is a cavity gap between the tubular vacuum bag and the outer vacuum bag film at the cut end of the cap-shaped stringer. The skin at this cavity gap is not subjected to sufficient pressure, which causes the skin fibers at the cut end of the cap-shaped stringer to wrinkle.

[0003] Therefore, this application is hereby submitted. Summary of the Invention

[0004] The purpose of this application is to provide a method for forming a cap-shaped stringer co-bonded wall panel.

[0005] This application is implemented as follows:

[0006] In a first aspect, this application provides a method for forming a cap-shaped stringer co-bonded wall panel, comprising:

[0007] Lay wet skin on the vehicle and arrange the cured cap-shaped stringers on the wet skin;

[0008] Obtain a fiberglass gasket, cover the opposite sides of the fiberglass gasket with a dry peelable cloth, and place it on the wet skin at one end of the cap-shaped stringer. The fiberglass gasket and the cap-shaped stringer are arranged sequentially along the length of the cap-shaped stringer, and the width of the fiberglass gasket is greater than the width of the cavity of the cap-shaped stringer.

[0009] Bag making is carried out using vacuum bag film laid on the outside of wet skin, cap-shaped stringer and fiberglass pad, and tubular vacuum bags inserted into cap-shaped stringer.

[0010] Vacuuming and hot pressing curing are performed.

[0011] In an optional implementation, the step of obtaining the fiberglass gasket includes:

[0012] At least two layers of fiberglass prepreg are laid on a flat plate, with the size of each layer gradually decreasing from bottom to top, so that the multilayer fiberglass prepreg forms a step at the edge;

[0013] Hot pressing and curing are performed to obtain the cured glass fiber gasket.

[0014] In an optional embodiment, the fiber extension directions of two adjacent layers of glass fiber prepreg are at an angle of 15° to 90°.

[0015] In an optional implementation, each layer of fiberglass prepreg is rectangular, with one side flush and the other three sides forming steps;

[0016] When placing the fiberglass pad on the wet skin at one end of the cap-shaped stringer, the stepless side of the fiberglass pad faces the end face of the cap-shaped stringer.

[0017] In an optional embodiment, in two adjacent layers of fiberglass prepreg, the lower layer of fiberglass prepreg extends 2 to 10 mm beyond the upper layer of fiberglass prepreg at the step.

[0018] In an optional embodiment, before hot-pressing and curing each layer of glass fiber prepreg, a vacuum bag is first made and the stacked multilayer glass fiber prepreg is evacuated; after hot-pressing and curing each layer of glass fiber prepreg, the vacuum bag is removed.

[0019] In an optional embodiment, the thickness of each layer of glass fiber prepreg is 0.05 to 0.3 mm.

[0020] In an optional embodiment, a release agent is applied to the fiberglass gasket before it is placed on the wet skin.

[0021] In an optional embodiment, the step of covering opposite sides of the fiberglass gasket with a dry peelable cloth includes:

[0022] Lay the dry peelable fabric on the wet skin at one end of the hat-shaped stringer;

[0023] Place the fiberglass gasket on the wet skin;

[0024] Fold the dry peelable fabric along the edge of the fiberglass gasket toward the hat-shaped stringer to cover the opposite sides of the fiberglass gasket.

[0025] In an optional embodiment, after covering the opposite sides of the fiberglass gasket with a dry peelable fabric and placing it on the wet skin at one end of the cap-shaped stringer, the forming method further includes sequentially laying an isolation film and a breathable felt on the dry peelable fabric.

[0026] This application has the following beneficial effects:

[0027] The method for forming a cap-shaped stringer co-bonded wall panel provided in this application includes laying a wet skin on a carrier, arranging the cured cap-shaped stringer on the wet skin; obtaining a fiberglass pad, covering the opposite sides of the fiberglass pad with a dry peelable cloth, and arranging it on the wet skin at one end of the cap-shaped stringer, with the fiberglass pad and the cap-shaped stringer arranged sequentially along the length of the cap-shaped stringer, the width of the fiberglass pad being greater than the width of the cavity of the cap-shaped stringer; making a bag using a vacuum bag film laid on the outside of the wet skin, the cap-shaped stringer and the fiberglass pad and a tubular vacuum bag inserted into the cap-shaped stringer; evacuating and hot-pressing for curing. By placing a fiberglass pad on the wet skin at one end of the cap-shaped stringer, the wet skin at this point can be stressed more evenly, avoiding gaps at the junction of the tubular vacuum bag, the outer vacuum bag film, and the wet skin. This prevents the wet skin at the corresponding position from lacking pressure and causing upward convex wrinkles, thus improving the quality of the co-bonded wall panel of the cap-shaped stringer. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a first schematic diagram of a hat-shaped stringer fixed to a wet skin in the relevant technology;

[0030] Figure 2 This is a second schematic diagram of a hat-shaped stringer fixed to a wet skin in a related technology;

[0031] Figure 3 This is a flowchart of a method for forming a cap-shaped stringer co-bonded wall panel in one embodiment of this application;

[0032] Figure 4 This is a schematic diagram showing the placement of the fiberglass gasket in one embodiment of this application;

[0033] Figure 5 This is a schematic diagram of the mounting of a glass fiber gasket in one embodiment of this application;

[0034] Figure 6 This is a schematic diagram of two layers of fiberglass prepreg laid in one embodiment of this application.

[0035] Explanation of key component symbols: 100-hat-shaped stringer; 110-hat body; 120-flange strip; 200-wet skin; 300-fiberglass gasket; 310-fiberglass prepreg; 400-dry peelable fabric; 500-separation membrane; 600-breathable felt; 700-carrier. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0037] Figure 1 This is a first schematic diagram of a hat-shaped stringer 100 fixed to a wet skin 200 in the relevant technology; Figure 2 This is a second schematic diagram showing the cap-shaped stringer 100 fixed to the wet skin 200 in the related technology. (See diagram below.) Figure 1 and Figure 2 As shown, in the co-bonding process, the wet skin 200 is typically laid on the carrier 700 first, and then the cured cap-shaped stringer 100 is fixed to the uncured wet skin 200 (containing prepreg), with the cavity of the cap-shaped stringer 100 facing downwards, and the flange strips 120 on both sides of the cap-shaped stringer 100 adhering to the wet skin 200. A vacuum bag is then made and a vacuum is created so that the cap-shaped stringer 100 can press tightly against the wet skin 200. When making the vacuum bag, a tubular vacuum bag is placed in the cavity formed by the cap body 110 of the cap-shaped stringer 100, and a vacuum bag film is laid on the outside of the wet skin 200 and the cap-shaped stringer 100, with the edge of the vacuum bag film sealed to the carrier 700. Then, the air between the tubular vacuum bag, the vacuum bag film, and the carrier 700 is removed, causing the vacuum bag film to press downwards tightly against the wet skin 200 and the cap-shaped stringer 100. The tubular vacuum bag adheres tightly to the inner wall of the cap body 110 and the wet skin 200 corresponding to the opening of the cavity formed by the cap body 110. This ensures that the flange 120 of the cap-shaped stringer 100 is tightly fitted to the wet skin 200, and the entire wet skin 200 is subjected to downward pressure (including pressure from the flange 120, the vacuum bag film, and the tubular vacuum bag). However, because the cap-shaped stringer 100 has a certain thickness, there will be gaps between the vacuum bag film, the tubular vacuum bag, and the wet skin 200 in a region outside its ends. These gaps correspond to the wet skin 200 (e.g., Figure 2 The area within the dashed square lacks downward pressure, which can cause upward convex wrinkles, resulting in poor quality of the wall panel structure produced later.

[0038] Therefore, this application provides a method for forming a cap-shaped stringer co-bonded wall panel, which improves the problem of wrinkles easily occurring at the end of the cap-shaped stringer by laying a fiberglass pad on the wet skin at the end of the stringer during vacuuming.

[0039] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0040] Figure 3 This is a flowchart illustrating a method for forming a cap-shaped stringer co-bonded wall panel according to one embodiment of this application. Figure 3 As shown, the molding method for the cap-shaped stringer co-bonded wall panel provided in this application embodiment includes:

[0041] Step S100: Lay wet skin on the vehicle and arrange the cured hat-shaped stringers on the wet skin.

[0042] In this embodiment, the cap-shaped stringer 100 is made of composite material, including fiber material and resin (cured). The cap-shaped stringer 100 includes a cap body 110 forming a cavity and flange strips 120 connected to both sides of the cap body 110. After the cap-shaped stringer 100 is arranged on the wet skin 200, the opening of the cavity formed by the cap body 110 faces the wet skin 200, and the flange strips 120 on both sides are attached to the wet skin 200.

[0043] To ensure a tight fit between the flange 120 of the cap-shaped stringer 100 and the wet skin 200, a pre-vacuum bag can be used for pre-vacuum treatment. This involves laying a vacuum bag film on the outside of both the wet skin 200 and the cap-shaped stringer 100, then drawing a vacuum to press the cap-shaped stringer 100 tightly against the wet skin 200; the vacuum bag film is then removed. This eliminates any potential gaps between the flange 120 and the wet skin 200, preventing materials used in subsequent processes (such as fiberglass gaskets) from entering between them and affecting product quality.

[0044] Step S200: Obtain a fiberglass gasket, cover the opposite sides of the fiberglass gasket with a dry peelable cloth, and place it on the wet skin at one end of the cap-shaped stringer. The fiberglass gasket and the cap-shaped stringer are arranged sequentially along the length of the cap-shaped stringer, and the width of the fiberglass gasket is greater than the width of the cavity of the cap-shaped stringer.

[0045] In this embodiment, the width of the fiberglass gasket refers to the dimension perpendicular to the extension direction of the cap-shaped stringer. Figure 4 This is a schematic diagram showing the placement position of the fiberglass gasket 300 in one embodiment of this application; Figure 5 This is a schematic diagram of the mounting of the fiberglass gasket 300 in one embodiment of this application. Figure 4 The area within the dashed box indicates the location of the fiberglass gasket 300. For example... Figure 4 and Figure 5 As shown, the width of the fiberglass gasket 300 is greater than the width of the cavity of the cap-shaped stringer 100, allowing the fiberglass gasket 300 to cover the two areas where wrinkles may occur (see reference). Figure 2 ).

[0046] Figure 6 This is a schematic diagram illustrating the laying of two layers of fiberglass prepreg 310 in one embodiment of this application. Figure 6 As shown, the fiberglass gasket 300 can be obtained further as follows:

[0047] Step S210: At least two layers of fiberglass prepreg 310 are laid on the flat plate, and the size of each layer of fiberglass prepreg 310 gradually decreases from bottom to top, so that the multilayer fiberglass prepreg 310 forms a step at the edge.

[0048] Step S220: Perform hot pressing curing to obtain the cured glass fiber gasket 300.

[0049] In this embodiment, a step is formed at the edge of the fiberglass gasket 300, which helps to reduce indentations caused by the edge of the fiberglass gasket 300 pressing against the wet skin 200. Figure 6 As shown, the fiberglass gasket 300 in this embodiment is made of two layers of fiberglass prepreg 310. The fiber extension directions of the two adjacent layers of fiberglass prepreg 310 are at an angle of 15° to 90°, which can reduce the anisotropy of the manufactured fiberglass gasket 300 and improve the structural strength of the fiberglass gasket 300. In this embodiment, the fiber angle between the two fiberglass prepregs 310 is 45°.

[0050] Optionally, in this embodiment, each layer of fiberglass prepreg 310 is rectangular, with one side flush and the other three sides forming steps. When the fiberglass pad 300 is placed on the wet skin 200 at one end of the cap-shaped stringer 100, the side of the fiberglass pad 300 without steps faces the end face of the cap-shaped stringer 100.

[0051] In this embodiment, the thickness of each layer of fiberglass prepreg 310 is 0.05–0.3 mm, for example, 0.1 mm. In two adjacent layers of fiberglass prepreg 310, the lower layer of fiberglass prepreg 310 extends beyond the upper layer of fiberglass prepreg 310 at the step. For example, in this embodiment, the lower layer of fiberglass prepreg 310 extends beyond the upper layer of fiberglass prepreg 310 at the step by an amount of 3 mm.

[0052] In alternative embodiments, the shape of the fiberglass prepreg 310 (or the final fiberglass gasket 300) may not be rectangular, but may be set to other shapes as needed, such as D-shape, with no step on one straight side. The number of layers of fiberglass prepreg 310 may also be increased as needed.

[0053] Before hot-pressing and curing each layer of fiberglass prepreg 310, a vacuum bag is first made and the stacked multilayer fiberglass prepreg 310 is evacuated. After hot-pressing and curing each layer of fiberglass prepreg 310, the vacuum bag is removed. During the vacuum bag making and evacuation process, the resin is more uniformly distributed in the fiberglass prepreg 310 to ensure that each layer of fiberglass prepreg 310 is pre-compressed and tightly bonded. Before laying the vacuum bag film, auxiliary materials such as release film and breathable felt can be laid to separate the vacuum bag film from the wet fiberglass prepreg 310. After hot-pressing and curing, these materials are removed along with the vacuum bag film.

[0054] Optionally, a release agent may be applied to the fiberglass gasket 300 before it is placed on the wet skin 200 so that the fiberglass gasket 300 can be removed after the molding process is completed.

[0055] Please see Figure 5 The step of covering the two opposite sides of the fiberglass gasket 300 with a dry peelable cloth 400 may specifically include:

[0056] Lay the dry peelable fabric 400 on the wet skin 200 at one end of the hat-shaped stringer 100; place the fiberglass pad 300 on the wet skin 200; fold the dry peelable fabric 400 along the fiberglass pad 300 toward the edge of the hat-shaped stringer 100 to cover the opposite sides of the fiberglass pad 300.

[0057] Specifically, ensure that the edge of the fiberglass gasket 300 is aligned with the end edge of the cap-shaped stringer 100, and that there are no gaps between the dry peelable fabric 400 and the end of the fiberglass gasket 300. The dry peelable fabric 400 is used to separate the fiberglass gasket 300 from the wet skin 200 and the release liner 500. This method allows for simple and efficient application of the dry peelable fabric 400 to both sides of the fiberglass gasket 300. Furthermore, the fiberglass gasket 300 can be fixed to the dry peelable fabric 400 using pressure-sensitive adhesive tape.

[0058] After laying the dry peelable fabric 400 and the fiberglass gasket 300, the release film 500 and the breathable felt 600 can be laid on the dry peelable fabric 400 in sequence. The breathable felt 600 can play a role in guiding air during subsequent vacuuming, making it easier to remove as much air as possible, so that the vacuum bag film is tightly pressed against the cap-shaped stringer 100, the wet skin 200 and the fiberglass gasket 300.

[0059] Step S300: Bag making is carried out using a vacuum bag film laid on the outside of the wet skin, the cap-shaped stringer and the fiberglass pad, and a tubular vacuum bag inserted inside the cap-shaped stringer.

[0060] This step is to press the cap-shaped stringer 100, fiberglass gasket 300 (and related dry peelable fabric 400, release film 500, and breathable felt 600) tightly against the wet skin 200 before entering the autoclave curing process, thus facilitating entry into the autoclave for curing. During bag making, a tubular vacuum bag is inserted into the cavity of the cap-shaped stringer 100, or the tubular vacuum bag can be pre-placed inside the cavity of the cap-shaped stringer 100 when it is placed on the wet skin 200; a vacuum bag film is laid on the outside of the cap-shaped stringer 100 and the wet skin 200, with its edges sealed to the carrier 700.

[0061] In this embodiment, since the fiberglass gasket 300 plays a pressure equalization role, the wet skin 200 corresponding to the gap between the tubular vacuum bag and the vacuum bag film can also be pressed by the fiberglass gasket 300, thus avoiding the formation of upward convex wrinkles at the original gap.

[0062] Step S400: Vacuum extraction and hot-press curing.

[0063] In this embodiment, the air between the tubular vacuum bag, the carrier 700, and the tubular vacuum bag is extracted, causing the outer vacuum bag film to press down on the wet skin 200, the cap-shaped stringer 100, and the fiberglass gasket 300. Then, the vacuum bag film, the tubular vacuum bag, and the fiberglass gasket 300, together with the wet skin 200 and the cap-shaped stringer 100, are thermo-cured using an autoclave.

[0064] After hot pressing and curing are complete, materials such as the vacuum bag film, tubular vacuum bag, fiberglass gasket 300, release film 500, and breathable felt 600 can be removed. The fiberglass gasket 300 can be reused in the next molding process after cleaning.

[0065] In this embodiment, the fiberglass gasket 300 acts as a pressure equalizing plate to balance the pressure of the wet skin 200 at the cut-off end of the cap-shaped stringer 100, thus improving the wrinkling problem of the skin at the cut-off end of the cap-shaped stringer 100. The fiberglass gasket 300 is prefabricated with a stepped design and is used in conjunction with a dry peelable fabric 400, which effectively reduces the indentations caused by the edges of the fiberglass gasket 300 on the wet skin 200 when pressure is applied. Furthermore, the fiberglass gasket 300 has a certain degree of flexibility and good conformability, allowing it to be used in the manufacture of co-bonded wall panels with different curvatures.

[0066] In summary, the molding method for the cap-shaped stringer 100 co-bonded wall panel provided in this application includes laying a wet skin 200 on a carrier 700, and arranging the cured cap-shaped stringer 100 on the wet skin 200; obtaining a fiberglass gasket 300, covering the opposite sides of the fiberglass gasket 300 with a dry peelable cloth 400, and arranging it on the wet skin 200 at one end of the cap-shaped stringer 100, with the fiberglass gasket 300 and the cap-shaped stringer 100 arranged sequentially along the length of the cap-shaped stringer 100, and the width of the fiberglass gasket 300 being greater than the width of the cavity of the cap-shaped stringer 100; making a bag using a vacuum bag film laid on the outside of the wet skin 200, the cap-shaped stringer 100 and the fiberglass gasket 300 and a tubular vacuum bag inserted inside the cap-shaped stringer 100; and vacuuming and hot-pressing curing. By placing a fiberglass pad 300 on the wet skin 200 at one end of the hat-shaped stringer 100, the wet skin 200 at this point can be subjected to more uniform force, avoiding gaps at the junction of the tubular vacuum bag, the outer vacuum bag film and the wet skin 200, which would cause the wet skin 200 at the corresponding position to lack pressure and form upward convex wrinkles. Therefore, the quality of the co-bonded wall panel of the hat-shaped stringer 100 can be improved.

[0067] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for forming a cap-shaped stringer co-bonded wall panel, characterized in that, include: A wet skin is laid on the vehicle, and the cured cap-shaped stringers are arranged on the wet skin; Obtain a fiberglass gasket, cover the opposite sides of the fiberglass gasket with a dry peelable cloth, and place it on the wet skin at one end of the hat-shaped stringer. The fiberglass gasket and the hat-shaped stringer are arranged sequentially along the length of the hat-shaped stringer, and the width of the fiberglass gasket is greater than the width of the cavity of the hat-shaped stringer. Bag making is carried out using a vacuum bag film laid on the outside of the wet skin, the cap-shaped stringer and the fiberglass pad, and a tubular vacuum bag inserted inside the cap-shaped stringer; Vacuum extraction followed by hot-press curing; The step of obtaining the fiberglass gasket includes: At least two layers of fiberglass prepreg are laid on a flat plate, with the size of each layer of fiberglass prepreg gradually decreasing from bottom to top, so that the multiple layers of fiberglass prepreg form steps at the edges; The glass fiber gasket is then subjected to hot pressing and curing to obtain the cured glass fiber gasket. Each layer of fiberglass prepreg is rectangular, with one side flush and the other three sides forming steps; When the fiberglass pad is placed on the wet skin at one end of the hat-shaped stringer, the stepless side of the fiberglass pad faces the end face of the hat-shaped stringer.

2. The method for forming the cap-shaped stringer co-bonded wall panel according to claim 1, characterized in that, The fiber extension directions of two adjacent layers of the glass fiber prepreg are at an angle of 15° to 90°.

3. The method for forming the cap-shaped stringer co-bonded wall panel according to claim 1, characterized in that, In two adjacent layers of fiberglass prepreg, the lower layer of fiberglass prepreg extends 2-10 mm beyond the upper layer of fiberglass prepreg at the step.

4. The method for forming the cap-shaped stringer co-bonded wall panel according to claim 1, characterized in that, Before hot-pressing and curing each layer of the fiberglass prepreg, a vacuum bag is first made and the stacked multilayer fiberglass prepreg is evacuated; after hot-pressing and curing each layer of the fiberglass prepreg, the vacuum bag is removed.

5. The method for forming the cap-shaped stringer co-bonded wall panel according to claim 1, characterized in that, The thickness of each layer of the glass fiber prepreg is 0.05~0.3mm.

6. The method for forming the cap-shaped stringer co-bonded wall panel according to claim 1, characterized in that, Before placing the fiberglass pad on the wet skin, apply a release agent to the fiberglass pad.

7. The method for forming the cap-shaped stringer co-bonded wall panel according to claim 1, characterized in that, The step of covering the opposite sides of the fiberglass gasket with a dry, peelable cloth includes: The dry peelable fabric is laid on the wet skin at one end of the hat-shaped stringer; Place the fiberglass pad on the wet skin; The dry peelable fabric is folded along the edge of the fiberglass pad toward the hat-shaped stringer to cover the opposite sides of the fiberglass pad.

8. The method for forming the cap-shaped stringer co-bonded wall panel according to claim 1, characterized in that, After covering the opposite sides of the fiberglass pad with a dry peelable fabric and placing it on the wet skin at one end of the cap-shaped stringer, the forming method further includes sequentially laying an isolation film and a breathable felt on the dry peelable fabric.

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