Bonded assembly for aircraft cabin interior equipment and associated bonded assembly method

Abstract

This method for bonding an element to a substrate comprises the steps of: applying a first group of adhesive strips (4a) to a first surface of the element, the strips (4a) of the first group being separated from each other and extending along a first principal direction (Dp1) relative to the first surface; applying a second group of adhesive strips (4b) to a second surface of the substrate, the strips (4b) of the second group being separated from each other and extending along a second principal direction (Dp2) relative to the second surface; and pressing the first bonded surface against the second bonded surface, the surfaces being positioned so that the first principal direction (Dp1) forms a predetermined non-zero angle (A) with the second principal direction (Dp2). Figure for the abstract: Figure 6

Description

Title of the invention: Bonded assembly for aircraft cabin interior equipment and associated bonded assembly method technical field

[0001] The present invention relates to the field of bonded assemblies, and in particular to bonded assemblies for aircraft cabin interior equipment. Previous techniques

[0002] Aircraft cabin interior materials and equipment are subject to several categories of approval tests designed to ensure a standardized level of control over safety risks in the event of a fire. For example, such tests are intended to assess flammability, the amount of heat generated, or the toxicity of gases emitted during a fire.

[0003] Aircraft cabin interior equipment generally comprises composite stacks often assembled using glue. For example, the fabric of a seat is glued to a foam which is itself glued to a polycarbonate backing.

[0004] Glue consumption or basis weight is the quantity of glue applied to a given surface and is measured in g / cm². To ensure sufficient adhesion, glue consumption must exceed a minimum value necessary to obtain sufficient bonding strength.

[0005] However, consumption should not be too high, as high glue consumption can increase safety risks in case of fire and can cause difficulties in passing approval tests.

[0006] Traditionally, determining the appropriate adhesive consumption value is a costly and time-consuming process. Indeed, numerous design iterations are required before finding a suitable value that both achieves good bonding and successfully passes homologation tests. Description of the invention

[0007] In this context, the invention aims at a glued assembly process that reduces glue consumption for a substantially equal level of bonding strength and thus increases the margin in homologation tests, thereby reducing the number of iterations required.

[0008] The invention relates to a method for gluing an element to a support. The method comprises the following steps: - application of a first group of adhesive strips to a first surface of the element to be glued, the strips of the first group being separated each of the bands in the first group having a predefined length extending along a principal direction relative to the first surface of the element, - application of a second group of adhesive strips to a second surface of the substrate to be glued, the strips of the second group being separated from each other, each of the strips of the second group having a second predefined length extending in a second principal direction relative to the second surface of the substrate, and - plating of the first glued surface against the second glued surface in a direction normal to the surfaces, the surfaces being positioned so that the first principal direction of the strips of the first group forms a predetermined non-zero angle with the second principal direction of the strips of the second group.

[0009] Thanks to the separation of the glue strips, it is possible to reduce glue consumption while maintaining the level of bonding strength.

[0010] Advantageously, the application of adhesive strips is carried out through a network of openings in a mask superimposed on the surface to be glued, each opening corresponding to a single adhesive strip. The use of such a mask ensures the separation of the adhesive strips.

[0011] Advantageously, the same mask is used for the application of both groups of adhesive strips.

[0012] According to a preferred feature, the application of the adhesive strips is carried out by spraying with a gun.

[0013] For example, the process includes an additional drying step carried out after the glue strip application steps and before the plating step.

[0014] According to another aspect, the invention relates to a bonded assembly comprising an element, a support, and a bonding zone interposed between the element and the support and adapted for bonding the element to the support. The bonding zone comprises a layer of adhesive of variable thickness and areas without adhesive. Such a bonded assembly makes it possible to reduce adhesive consumption without reducing the bonding strength.

[0015] Preferably, the variable thickness of the glue layer has either a low value representing gluing with a single strip of glue, or a high value representing gluing with a strip of glue from each group.

[0016] For example, the surface area ratio of the parts without glue and the glued surface ranges from 10% to 50%.

[0017] According to one feature, the distance between a glue-free area and the nearest glue layer is less than or equal to the smallest width of the glue strips.

[0018] According to another aspect, the invention relates to interior equipment for an aircraft cabin comprising at least one bonded assembly as defined above. Brief description of the drawings

[0019] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0020] [Fig-1] is a flowchart of a method for gluing an element onto a support according to an example of an embodiment of the invention;

[0021] [Fig.2] is a partial plan view of a first surface of the glued element according to a step of application of a first group of glue strips of the [Fig.1];

[0022] [Fig.3] is a partial plan view of a second surface of the substrate glued according to an application step of a first group of glue strips of the [Fig.1];

[0023] [Fig.4] is a partial plan view of a mask used during at least one step of applying adhesive strips in the process of [Fig.1];

[0024] [Fig. 5] is a partial cross-sectional view of a bonded assembly obtained by the process of [Fig. 1]; and

[0025] [Fig.6] is a partial plan view of a bonding area obtained after a plating step of the first glued surface against the second glued surface of [Fig.1]. Detailed description of at least one embodiment

[0026] Figure [1] shows a flowchart of a method for gluing an element 1 onto a support 2 according to an example of an embodiment of the invention.

[0027] The process begins here with a step 100 of applying a first group 3a of strips 4a of glue onto a first surface la to be glued of the element 1.

[0028] As shown in [Fig.2], the bands 4a of the first group 3a are separated from each other. In other words, the bands 4a neither intersect nor touch.

[0029] Each of the strips 4a of the first group 3a has a predefined first length L1 which extends along a first principal direction Dpi relative to the first surface la of the element 1. Preferably, the length L1 is the same for all the strips 4a. Alternatively, it is possible to provide strips 4a having different lengths L1 from each other.

[0030] After gluing the first surface 1a, the process continues with a step 200 of applying a second group 3b of strips 4b of glue onto a second surface 2b to be glued of the support 2.

[0031] As shown in [Fig. 3], the 4b bands of the second group 3b are separated from each other. In other words, the 4b bands do not intersect or touch each other.

[0032] It should be noted that similar or identical elements bear the same references from one figure to another.

[0033] Each of the bands 4b of the second group 3b has a second predefined length L2 which extends along a second principal direction Dp2 with respect to the second surface 2b of the support 2.

[0034] Preferably, the length L2 is the same for all 4b strips. Alternatively, it is possible to provide 4b strips having different lengths L2 from each other.

[0035] Preferably, the strips 4a and 4b have the same length, i.e., length L1 is equal to length L2. Alternatively, it remains possible to provide for different lengths L1, L2.

[0036] Preferably, each strip 4a, 4b of glue has a predefined width Lal, La2 extending along a secondary direction Dsl, Ds2 perpendicular to the main direction Dpi, Dp2.

[0037] Preferably, the widths Lal and La2 are respectively the same for all bands 4a and 4b. Alternatively, it is possible to provide bands of different widths within the same group 3a and / or 3b.

[0038] Preferably, the width Lal is equal to the width La2. Alternatively, it remains possible to provide for different widths Lal, La2.

[0039] The bands 4a, 4b are longer than they are wide. In other words, each band 4a has a length L1 greater than its width L1, and each band 4b has a length L2 greater than its width La2.

[0040] Preferably, the application of adhesive strips 4a, 4b is carried out through a network of openings O in a mask M superimposed on the surface la, 2b to be glued and illustrated in [Fig. 4]. Each opening O corresponds to a single adhesive strip 4a, 4b. Preferably, each opening O has a shape complementary to the associated adhesive strip.

[0041] In a preferred embodiment, the application of the 4a, 4b adhesive strips is carried out by spraying with a gun through the mask M.

[0042] According to one embodiment, the same mask M is used for applying the two groups 3a, 3b of adhesive strips, provided that the openings O are oriented differently with respect to the surfaces 1a, 2b to be bonded. This different orientation can be easily obtained by a partial rotation R of the mask M with respect to the surface to be bonded, for example 90°. When a single mask M is used for bonding the surfaces 1a, 2b, the groups 3a and 3b of strips are identical, except for a rotation R.

[0043] Alternatively, it remains possible to use a different mask M for each of the surfaces la, 2b to be glued, allowing to obtain different groups 3a and 3b or different strips 4a and 4b.

[0044] By way of example, the adhesive used for the adhesive strips 4a, 4b may be of the cyanoacrylate type, for example ethyl cyanoacrylate (Permabond 2011) or liquid cyanoacrylate. Another type of adhesive that may be used is a mixture known under the brand name Montaprene.

[0045] After the application step 200, a plating step is performed of the first glued surface la against the second glued surface 2b in a direction normal to the surfaces la, 2b (step 400). During the plating step, the surfaces la, 2b are positioned so that the first principal direction Dpi of the strips 4a of the first group 3a forms a predetermined non-zero angle A with the second principal direction Dp2 of the strips 4b of the second group 3b ([Fig.6]).

[0046] Preferably, the process includes an additional drying step 300 carried out after the application steps 100, 200 of the adhesive strips 4a, 4b and before the plating step 400.

[0047] Generally, the gluing of the first surface 1a of element 1 and the gluing of the second surface 2b of support 2 can be carried out successively or simultaneously. In the illustrated bonding process, step 200, the application of the second group 3b of strips 4b, is carried out after step 100, the application of the first group 3a of strips 4a. Alternatively, it is possible to have step 200, the application of the second group 3b of strips 4b, carried out before or at the same time as step 100, the application of the first group 3a of strips 4a.

[0048] Figure 5 is a partial cross-sectional view of a bonded assembly 5 obtained by a bonding process as described above. According to one application example, such a bonded assembly can be part of the interior fittings of an aircraft cabin.

[0049] The glued assembly 5 comprises an element 1, a support 2 and a bonding zone 6 interposed between the element 1 and the support 2 and adapted for gluing the element 1 to the support 2. The bonding zone 6 comprises a layer C of glue of variable thickness and parts 7 without glue.

[0050] The variable thickness of the adhesive layer C has either a low value, denoted "el", or a high value, denoted "e2", the high value e2 being greater than the low value el. In other words, the variable thickness takes only two distinct, non-zero values. The low value el represents bonding with a single strip 4a or 4b of adhesive. The high value e2 represents bonding with a strip 4a and 4b of adhesive from each group 3a, 3b.

[0051] Preferably, the surface area ratio between the glue-free parts 7 and the glued surface la, 2b ranges from 10% to 50%. In other words, the glue-free surface represents 10% to 50% of each surface la, 2b.

[0052] The glue-free parts 7 are particularly visible on [Fig.6], which is a partial plan view of a glued area 6.

[0053] Preferably, the distance measured on the glued surface la, 2b between a part without glue and the nearest layer of glue is less than or equal to the smallest width of the glue strips, so as to ensure homogeneity of gluing.

Claims

Demands

1. A method for bonding an element (1) to a support (2) characterized in that it comprises the steps of: - applying a first group (3a) of adhesive strips (4a) to a first surface (la) to be bonded of the element (1), the strips (4a) of the first group (3a) being separated from each other, each of the strips (4a) of the first group (3a) having a first predefined length (L1) extending along a first principal direction (Dpi) with respect to the first surface (la) of the element (1), - applying a second group (3b) of adhesive strips (4b) to a second surface (2b) to be bonded of the support (2), the strips (4b) of the second group (3b) being separated from each other, each of the strips (4b) of the second group (3b) having a second predefined length (L2) extending along a second principal direction (Dp2) with respect to the second surface (2b) of the support (2),and - plating of the first glued surface (la) against the second glued surface (2b) in a direction normal to the surfaces (la, 2b), the surfaces (la, 2b) being positioned so that the first principal direction (Dpi) of the strips (4a) of the first group (3a) forms a predetermined non-zero angle (A) with the second principal direction (Dp2) of the strips (4b) of the second group (3b).

2. Assembly method according to claim 1, wherein the application of strips (4a, 4b) of glue is carried out through a network of openings (0) of a mask (M) superimposed on the surface (la, 2b) to be glued, each opening (0) corresponding to a single strip (4a, 4b) of glue.

3. Assembly method according to claim 2, wherein the same mask (M) is used for the application of both groups (3a,3b) of adhesive strips.

4. Assembly method according to claim 2 or 3, wherein the application of the strips (4a, 4b) of glue is carried out by spraying with a gun.

5. Assembly method according to any one of claims 1 to 4, comprising an additional drying step carried out after the steps of applying the strips of glue (4a, 4b) and before the plating step.

6. A bonded assembly obtained by a process according to any one of claims 1 to 5, comprising a bonding zone (6) interposed between the element (1) and the support (2) and adapted to bond the element (1) to the support (2), the bonding zone (6) comprising a layer (C) of glue of variable thickness and parts (7) without glue.

7. Glued assembly according to claim 6, wherein the variable thickness of the glue layer (C) has either a low value (el) representing a gluing with a single strip (4a, 4b) of glue, or a high value (e2) representing a gluing with a strip (4a, 4b) of glue from each group (3a, 3b).

8. Glued assembly according to claim 6 or 7, wherein the surface area ratio of the glue-free parts (7) and the glued surface (la, 2b) ranges from 10% to 50%.

9. Glued assembly according to any one of claims 6 to 8, wherein the distance between a glue-free part (7) and the nearest glue layer (C) is less than or equal to the smallest width (Lal, La2) of the glue strips (4a, 4b).

10. Aircraft cabin interior equipment comprising at least one bonded assembly according to any one of claims 6 to 9.

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