Method for manufacturing a wall for a housing and wall manufactured by such a method

Abstract

Method for producing a wall (25) for a housing (3), wherein the wall (25) comprises a layer (251) of a porous first material and at least one film (253) of a second material arranged on at least one circumferential region (Z2) of the layer (251), the method comprising the following steps: - Arranging a film (253) from the second material at a predefined location in a form (M), - Heating a layer (251) of the porous first material, - Arranging the layer (251) of the porous first material in the mold such that at least one circumferential area (Z2) of the layer (251) of the porous first material covers the film (253) of the second material, - Closing the mold (M) for a predetermined duration and compressing the circumferential area (Z2) of the layer (251) made of the porous first material and the film (253) made of the second material, such that a predetermined thickness is obtained and the film (253) merges with the layer (251) made of the porous first material at the level of the circumferential area (Z2), characterized in that during the compression step by closing the mold (M) the volume of the layer (251) made of the porous first material at the level of the compressed and circumferential area (Z2) is reduced by a factor of four to eight in relation to the volume of the remaining layer (251) made of the first material.

Description

[0001] The present invention relates to the field of systems for heating, ventilating, and / or air conditioning the passenger compartment of a motor vehicle, also known as HVAC (heating, ventilation, and air conditioning). The invention relates in particular to a method for producing a wall made of porous material for a housing, such as the housing of a heating and / or ventilation and / or air conditioning system, especially for a motor vehicle.

[0002] Motor vehicles are usually equipped with a system for ventilating, heating and / or air conditioning an airflow, so that the aerothermic parameters of the airflow to be distributed to the interior of the vehicle passenger compartment can be adjusted.

[0003] Such a system comprises a housing, generally enclosed by walls, and featuring at least one air inlet and at least one air outlet. The housing contains an air blower that circulates the airflow from the air inlet to the air outlet.

[0004] The housing also generally accommodates heat treatment devices, such as heat exchangers for heating and / or cooling the airflow before its distribution inside the passenger compartment.

[0005] The airflow, which is pressurized by the air blower, is directed to the heat exchanger(s) via outlet openings or distribution openings that lead into different areas of the passenger compartment before being distributed in the passenger compartment.

[0006] Such housings are usually made of plastic and are generally formed from two housing halves that define an internal volume, with the heat exchangers and air blower arranged between the two housing halves.

[0007] However, in order to support the heat exchangers, the structure of such housings must be sufficiently resistant and have a relatively strong thickness, generally being made of rigid plastic.

[0008] However, the system can generate a loud noise inside during operation, both due to the movement of the airflow in the ducts and the operation of the blower. This noise can propagate into the passenger compartment, particularly through the housing's outlet openings. This then constitutes a noise nuisance for the vehicle's occupants.

[0009] To eliminate this problem, prior art solutions involve increasing the thickness of the system's inner walls so that they can absorb some of the noise emissions before they reach the distribution openings. However, these solutions have the disadvantage of significantly increasing the system's mass and thus the energy consumption of the vehicle equipped with it.

[0010] According to another known solution, the system has at least one wall made of porous material, positioned at the level of an opening in the housing structure, thus ensuring improved noise reduction while simultaneously reducing the system's mass. The connection between such a wall of porous material and the housing structure is achieved by molding the material of the perforated housing structure onto the wall of porous material.

[0011] The generic patent JP 2015-189 412 A shows a shaft of a vehicle air conditioning system, the wall of which is formed from two layers of foamed material laminated together under the influence of heat and thereby compressed.

[0012] It is therefore necessary to consider the difficulties associated with injection molding for this connection, which can only be carried out before the assembly of the housing and all the elements it contains. This assembly process cannot therefore simply be performed on an assembly line for a heating and / or ventilation and / or air conditioning system for a motor vehicle.

[0013] Another problem is the handling of the requirements regarding tightness, especially airtightness at the connection point between such a wall made of porous material and the housing structure.

[0014] The object of the invention is to at least partially solve these problems from the prior art by proposing a method by which an improved wall made of porous material can be produced, which helps to ensure the tightness at the level of the connection point between this wall and a corresponding structure, in particular a housing of a heating and / or ventilation and / or air conditioning system.

[0015] For this purpose, the invention relates to a method for producing a wall for a housing with the features of claim 1. In the compression step by closing the mold, the volume of the layer of the porous first material at the level of the compressed and surrounding area is reduced by a factor of four to eight compared to the volume of the remaining layer of the first material.

[0016] With this method, during compression, the surface of the film on the side of the layer mixes superficially with the fibers of the porous first material, while on the other side, which faces away from the layer and is in direct contact with the smooth form, the surface of the film is smoothed. This gives the compressed area of ​​the wall a smooth appearance.

[0017] If, after heating and compression, the porous layer has a granular surface texture, the excess material formed by the film, as described in this process, allows the compressed and surrounding area of ​​the porous wall to be adjusted, resulting in a smooth surface. This ensures better airtightness at the interface between the wall and the corresponding structure during bonding.

[0018] The order of at least some steps in this process can be reversed.

[0019] The manufacturing process may also include one or more of the following features, which are described below and can be considered individually or in combination.

[0020] The layer of the first material can have one or more predefined areas, each designed to cover a film of the second material and to be compressed according to the procedure defined above.

[0021] The second material of the film is selected in such a way as to promote the impregnation of the film, which was added to the predefined area(s), such as the surrounding area of ​​the layer.

[0022] The porosity of the porous first material is greater than 0.8.

[0023] The diameter of the pores is, for example, between 10 µm and 100 µm.

[0024] The porous first material is preferably a mixture of polyethylene terephthalate and polypropylene. According to a particular embodiment, the second material can be polypropylene.

[0025] The layer of the first material can be heated to a temperature lower than the melting temperature of the second material.

[0026] The layer of the first material can be heated to a temperature between 150°C and 230°C.

[0027] Before compression, the layer of porous first material has a first thickness on the order of 3.5 mm to 4 mm, and the compressed and surrounding area of ​​the wall has a second thickness on the order of 0.3 mm to 1.5 mm. The second thickness is preferably on the order of 0.9 mm.

[0028] The film made from the second material initially has a thickness on the order of 0.2 mm or 0.3 mm.

[0029] The mold is a hot forming tool.

[0030] Optionally, the mold is heated during the arrangement of the layer of porous first material.

[0031] According to another option, the layer of porous first material is first heated before being arranged in the mold, the process including a step to transfer the heated layer of porous first material into the mold.

[0032] The transfer step has a duration of less than 10 s, preferably less than 7 s.

[0033] During the compression step, the mold cools the layer of porous first material.

[0034] The closing time of the mold can be less than 1 minute and, according to one particular example, is on the order of 30 seconds.

[0035] During the compression step by closing the mold, the layer of porous first material at the level of the compressed and surrounding area can be shaped in such a way that it has a connection interface which is designed for connection with a corresponding structure by interlocking.

[0036] According to a specific example, the connection interface can be bent or folded to form a groove designed to receive an associated connecting element, which is shaped like a tab. The connection interface can be designed with one or more fastening elements, for example, by snapping.

[0037] The invention also relates to a wall produced using the previously defined method. Such a wall is designed for easy connection with a corresponding structure, in particular a housing of a system for heating and / or ventilating and / or air conditioning an airflow for a motor vehicle.

[0038] The wall according to the invention comprises a layer of a porous first material, which has at least a first region and a second region compressed with respect to the first region and which is arranged at least partially at the edge of the wall. This compressed second region comprises a film of a second material.

[0039] Further advantages and features of the invention will become clearer upon reading the following description, which is given as an illustrative and non-limiting example, and the accompanying drawings. These show: Fig. 1 a profile view of a housing of a heating, ventilation and / or air conditioning system with a wall which is produced using a method according to the invention. Fig. 2 a sectional view of an example of a wall produced according to the invention. Fig. 3 a schematic view of one step of the process for manufacturing the wall from Fig. 2, in which a film is arranged in one half of the mold. Fig. 4 a sectional view of another example of a wall obtained according to the invention.

[0040] In these figures, identical elements have the same reference symbols.

[0041] The following descriptions are examples. Even if the description refers to one or more embodiments, this does not necessarily mean that each reference pertains to the same embodiment or that the features are applicable to only a single embodiment. Simple features of different embodiments can also be combined or exchanged to provide further embodiments.

[0042] In the description, certain elements can be assigned a number, such as a first element or a second element. This serves as a simple identifier to distinguish and name similar but not identical elements. This identifier does not imply any priority of one element over another, and such designations can easily be interchanged without altering the scope of the present description. This identifier also does not establish a chronological order.

[0043] Reference will first be made to Fig. Figure 1 shows a profile view of a heating and / or ventilation and / or air conditioning system 1, in particular for a motor vehicle. Fig. 1 is such a facility 1.

[0044] Annex 1 comprises a housing 3 with at least one air inlet and one air outlet. The housing 3, in particular its walls, defines an air duct 5 in which an airflow flows, intended to be thermally treated and directed into the passenger compartment of the motor vehicle. The housing 3 may be formed from two housing halves.

[0045] Housing 3 can accommodate various elements of system 1, which are described below.

[0046] The system 1 generally includes an air blower 7, also called a fan assembly or referred to by the English term "blower". An airflow F originating from the exterior or interior of the vehicle can be drawn in by the air blower 7 and transported within the housing 3.

[0047] The system 1 generally includes one or more heat treatment devices such as heat exchangers 9, 11, 13, e.g. an evaporator 9, a heating / cooling element 11 and possibly an additional electric heating / cooling element 13 for heating and / or cooling the airflow F before its distribution in the passenger compartment of the motor vehicle.

[0048] In the housing 3, one or more flaps 15 are generally arranged so that an airflow or airflows are distributed or mixed at the outlet of one or more of the heat exchangers 9, 11, 13.

[0049] The housing 3 has one or more air outlet openings 17, 19, for example for defrosting / clearing or ventilation, which open into one or more parts or areas of the passenger compartment.

[0050] The housing 3 has distribution lines 21, 23, with which it is possible to direct and guide the airflow F, which has flowed through one or more of the heat exchangers 9, 11, to the outlet openings 17, 19.

[0051] Furthermore, the housing 3 has a perforated structure 30 with one or more openings 32. The arrangement of the opening 32, as shown in Fig. Figure 1, shown schematically, serves for illustration purposes and can be provided at any other suitable location.

[0052] The perforated structure 30 corresponds to a casing made of a rigid material, enabling it to withstand torsional and bending stresses. This is generally a plastic or thermoplastic. For example, it could be polypropylene, filled with talc or glass fibers, or not.

[0053] The openings 32 are arranged in a suitable manner to reduce noise pollution. This prevents the presence of rigid material in areas of the housing 3 where sound absorption is desired. The openings 32 are advantageously provided in the circulation path of the airflow F outside the heat exchangers 9, 11, 13. The openings 32 can be provided, in particular, near the air outlets, i.e., the outlet openings 17, 19.

[0054] The housing 3 further comprises at least one wall 25 which is arranged at the level of a corresponding opening 32 of the perforated structure 30, so that this opening 32 is closed, covered.

[0055] This wall 25 is manufactured using a manufacturing process that is described below.

[0056] The method makes it possible to shape the wall 25 depending on the opening 32 of the perforated structure 30 that the wall 25 is intended to close. The manufactured wall 25 must have a shape that is complementary to that of the corresponding opening 32. In the very schematic example of Fig. In section 1, the wall 25 has the shape of a plate to close a rectangular opening 32. Of course, any other shape can be considered.

[0057] The process generally comprises various steps for forming and firmly bonding a layer 251 of a first material and a film 253 of a second material, which are in Fig. 2 can be seen.

[0058] The porous first material has a structure characterized by the presence of multiple open and / or closed pores. Due to its porous nature and mechanical flexibility, this material provides sound insulation, thereby reducing noise pollution. This first material is selected based on its sound absorption properties. In particular, the sound absorption properties improve with increasing thickness of the first material. The dimensions of the porous first material are determined by a compromise between a thickness that allows for improved sound absorption and a thickness that is compatible with the overall architecture of the housing 3 and the system 1. Fig. 1 is homogeneous.

[0059] The first material is particularly suitable for damping sound waves with a frequency between 20 Hz and 20 kHz, thereby improving acoustic comfort in the passenger compartment of the vehicle and reducing noise generated within the system 1.

[0060] The porous first material can also be selected depending on its elasticity, extensibility, and tensile stresses.

[0061] The porosity of the porous first material of wall 25 is determined according to requirements. For example, the porosity of the porous first material is greater than 0.8. Porosity is the ratio between the volume of the pores and the total volume of a porous medium. A porosity greater than 0.8 represents a favorable condition for the formation of a wall 25 with improved noise reduction and high compliance.

[0062] According to one embodiment, the pore diameter can be between 10 µm and 100 µm.

[0063] The porous first material can be a single material or a mixture of materials. It can include, in particular, a foam, a non-woven material, a material woven with mineral wool, for example, or any polymer with or without glass fibers or hemp fibers, polypropylene, especially unreinforced polypropylene, polyurethane, or polyethylene.

[0064] The porous first material advantageously comprises polypropylene, known by the abbreviation PP, and is optionally mixed with another material. Polypropylene has the advantage of being lightweight while possessing satisfactory mechanical resistance for its intended use.

[0065] According to a non-restrictive particular embodiment, the porous first material is a mixture of poly(ethylene terephthalate), known by the abbreviation PET, and polypropylene PP.

[0066] The second material may differ from the first. Different materials are understood to mean materials with different compositions.

[0067] If the first material is a mixture of materials, the second material is advantageously one of the materials from this mixture, so that the impregnation described below is favored.

[0068] According to one option, the second material is, for example, polypropylene. This is particularly advantageous if the porous first material of layer 251 is a mixture of poly(ethylene terephthalate) and polypropylene.

[0069] Again with reference to Fig. 2. The film 253 made of the second material is provided for arrangement on at least one predefined area of ​​layer 251, in particular on a circumferential area of ​​layer 251. The predefined area preferably extends over the entire circumferential edge of the wall 25. It can also be said that the predefined area extends over the perimeter of the wall 25.

[0070] In its initial state, layer 251 can have at least one flat section or can have the overall shape of a flat plate.

[0071] The film 253, in turn, can have a predetermined shape that is adapted to the predefined area of ​​layer 251 that it is intended to cover. In the example of Fig. Initially, the film 253 has the overall form of a frame.

[0072] The process comprises a step for arranging the film 253 made of the second material at a predefined location in a mold. This mold is, for example, a hot-forming tool. The film 253 can, in particular, be arranged in one mold half M, which is intended to form the mold with another (not shown) complementary mold half.

[0073] The process includes a step to heat layer 251 (in Fig. (2 can be seen) from the porous first material. Layer 2511 can be heated completely.

[0074] The heating step serves to make the layer 251 of porous material more pliable, and makes it possible to simplify the shaping of the wall 25.

[0075] The temperature and holding time conditions during heating are adjusted according to the first material so that the desired shape is obtained.

[0076] The heating step can take place at a temperature below the melting point of the second material. As a non-restrictive example, the heating temperature could be between 150°C and 230°C, for example, approximately 160°C to 190°C.

[0077] The heating step can be performed for a predefined duration, which may be less than one minute. This duration varies depending on the porous initial material and its initial thickness. According to the specific example described, for layer 251, which is made from a PET-PP mixture of polyethylene terephthalate and polypropylene and has an initial thickness of 3.5 mm to 4 mm, the heating duration can be approximately 30 seconds.

[0078] Wall 25 can then be shaped with different areas Z1, Z2.

[0079] The process includes a step for arranging layer 251 of the porous first material in the mold, in particular in the Fig. 3 schematically represented half of form M.

[0080] According to one option, layer 251 ( Fig. 2) first heated before being placed in the mold, in particular in the mold half M of Fig. 3 is arranged. Layer 251 is warm when it is placed in the mold and arranged there. In this case, the method comprises a step to transfer the heated layer from the porous first material into the mold M. The transfer step takes less than 10 s, preferably less than 7 s.

[0081] According to another option, the mold can be heated when layer 251 is arranged from the porous first material.

[0082] According to one option or another, the layer 251 is arranged in the shape M such that at least one predefined area, in particular a circumferential area of ​​the layer 251 made of the porous first material, covers the film 253 made of the second material already arranged in the shape.

[0083] The mold can then be closed for a predefined duration, thereby compressing at least the predefined area of ​​layer 251 made from the porous first material and the film 253 made from the second material. The wall 25 is formed by the impression of the mold. This mold impression is thus designed to enable compression, particularly at the perimeter of layer 251. Such compression could also be provided at the level of other areas, e.g., in the middle of layer 251.

[0084] As in Fig. As shown in Figure 2, the wall 25 thus defines at least one first region Z1 of layer 251 without the film 253 and at least one circumferential second region Z2 of layer 251 that is covered with the film 253. In other words, the circumferential second region Z2 extends at the edge of the wall 25 or at the perimeter of layer 251.

[0085] Wall 25 can be shaped such that the first region Z1 is not compressed and only the second region Z2 is compressed. Alternatively, regions Z1 and Z2 can be compressed with different compression ratios, so that the second region Z2 is more compressed than the first region Z1. The second region Z2 will subsequently be referred to as the compressed second region Z2.

[0086] This compression step allows a predetermined thickness of the compressed second region(s) to be obtained.

[0087] The compression depends on the compliance of the porous material. In general, the need to reduce the thickness at the level of the second region Z2 increases with increasing compliance of the porous material.

[0088] The purpose of compression is, for example, to reduce the volume at the level of the second region Z2 by a factor of six to eight compared to the volume of the first region Z1. The first region Z1 can, for example, have a first thickness e1 on the order of 3.5 mm to 4 mm. The compressed second region Z2 can have a second thickness e2 on the order of 0.3 mm to 1.5 mm, particularly on the order of 0.9 mm. This applies in particular to the example of a wall 25 made from a PET-PP mixture of polyethylene terephthalate and polypropylene.

[0089] According to an alternative configuration not shown, wall 25 can have several first regions Z1 separated by a second region Z2. The different first regions Z1 can have the same thickness e1. Alternatively, the different first regions Z1 can have different thicknesses that remain greater than the thickness e2 of the second region Z2. As a variant or addition, wall 25 can have several predefined second regions Z2, each of which is to be covered with a film of the second material.

[0090] The fibers of the porous first material bond together when heated, resulting in a material comparable to rigid plastic.

[0091] When the film 253 comes into contact with the heated layer 251 at the level of the second area Z2, particularly the circumferential area, it can also soften due to the temperature of the first material. The first material 251 then mixes superficially with the second material of the film 253. More precisely, it is the side of the film 253 opposite and in contact with layer 251 that bonds with the fibers of the porous first material. On the other side, which is opposite layer 251 and in direct contact with the mold, the film 253 is smoothed during compression.

[0092] The second material of film 253 is selected to promote the impregnation of the film added to the second area Z2, such as the surrounding area of ​​layer 251. The second material is selected with a melting temperature below that of the first material.

[0093] To promote this impregnation, the thickness of film 253 is chosen to be sufficiently thin, e.g., on the order of 0.2 mm or 0.3 mm. Upon contact with the heated layer 251, the thin thickness of film 253 can thus penetrate the fibers of the softened porous first material.

[0094] The film 253 thus forms a material surplus with which it is possible to give a smooth appearance to the surface of the compressed second area Z2 of the wall 25. This smooth surface of the wall 25 helps to ensure airtightness at the level of the second area Z2, in particular the surrounding area, which is intended to form an interface with a corresponding structure 30, e.g., the housing 3, when connected ( Fig. 1).

[0095] The compression also enables a stiffening of the second area Z2, which is sufficient to ensure a function for connection with the corresponding structure 30.

[0096] At the in Fig. The illustrated example 2 is the manufactured wall 25 with a straight perimeter edge, shown here in the form of a frame.

[0097] Alternatively, during the compression step, by closing the mold, the compressed second area Z2 of the wall 25 can be shaped so that it has one or more connection interfaces with a special shape.

[0098] Such a connection interface is shaped to conform to the shape of the housing, particularly around the opening that the wall 25 is intended to cover. This connection interface can be designed to connect to the corresponding structure, for example, by positive locking. The connection interface is intended, for example, to be connected by interaction with an associated connecting element provided on the structure. This interaction is advantageously achieved by a simple mechanical connection, e.g., in a non-restrictive manner corresponding to a tongue-and-groove connection. According to a Fig. In the particular example shown in Figure 4, the connection interface 27 can be bent or folded such that a groove 29 is defined, which is provided for receiving an associated connecting element designed in the form of a tab. Furthermore, the connection interface can advantageously be designed to be attached to the structure 30 via a snap-fit ​​connection.

[0099] During the compression step, the mold cools layer 251 of the porous first material, which is covered with film 253 on the second area Z2. Layer 251 can cool until it reaches a predefined cooling temperature. As an illustrative example, the cooling temperature can be between 50°C and 90°C, preferably around 70°C.

[0100] After the wall 25 has cooled, it can be demolded. Upon opening the mold, the cooled wall 25 has assumed the desired permanent shape. According to the described embodiment, the wall 25 is thin and stiffened at the level of the second region Z2, in particular the circumferential region. The film 253 is smoothed at the level of the second region Z2 and merged with the layer 251 of the porous first material 251, thereby ensuring its smooth appearance.

[0101] Advantageously, at least one surface of wall 25 is flattened during the compression step. This flat surface should face the interior of the air duct or air channel defined by the housing. Regarding the orientation of wall 25 in the Fig. 2 or Fig.4 refers to the top surface. This prevents surface irregularities and air turbulence from being created, unlike with a wall 25, which is not uniformly flat.

[0102] Using the method described above, it is thus possible to produce a wall 25 with at least one first region Z1 of the layer 251 made of the porous material for sound absorption and at least one compressed second, in particular circumferential, region Z2, at the level of which the film 253 is smooth on one side and bonded to the layer 251 on the other. The compressed second region Z2 of the wall 25 is stiffened and thus has a smooth surface finish. It is designed to form the interface with the corresponding structure 30.

[0103] The wall 25 thus produced forms a field that can be connected to and attached to the structure 30 by any suitable means, so that an opening 32 is covered. When connecting, the smooth surface at the level of the compressed second area Z2 of the wall 25 ensures airtightness at the level of the connection point between the wall 25 and the structure 30.

[0104] Depending on requirements, consideration could be given to increasing the tightness of the connection by adding, for example, a seal such as an O-ring (not shown).

Claims

[1] Method for producing a wall (25) for a housing (3), wherein the wall (25) comprises a layer (251) of a porous first material and at least one film (253) of a second material arranged on at least one circumferential region (Z2) of the layer (251), the method comprising the following steps: - Arranging a film (253) from the second material at a predefined location in a form (M), - Heating a layer (251) of the porous first material, - Arranging the layer (251) of the porous first material in the mold such that at least one circumferential area (Z2) of the layer (251) of the porous first material covers the film (253) of the second material, - Closing the mold (M) for a predetermined duration and compressing the circumferential area (Z2) of the layer (251) made of the porous first material and the film (253) made of the second material, so that a predetermined thickness is obtained and the film (253) merges with the layer (251) made of the porous first material at the level of the circumferential area (Z2), characterized by , that during the compression step by closing the mold (M) the volume of the layer (251) made of the porous first material at the level of the compressed and surrounding area (Z2) is reduced by a factor of four to eight in relation to the volume of the remaining layer (251) made of the first material. [2] Method according to any of the preceding claims, wherein the porous first material is a mixture of poly(ethylene terephthalate) and polypropylene and the second material is polypropylene. [3] Method according to one of the preceding claims, wherein the layer (251) of the first material is heated to a temperature between 150°C and 230°C. [4] Method according to one of the preceding claims, wherein the layer (251) of the porous first material has a first thickness (e1) on the order of 3.5 mm to 4 mm before compression and the compressed and circumferential area (Z2) of the wall (25) has a second thickness (e2) on the order of 0.3 mm to 1.5 mm. [5] Method according to any of the preceding claims, wherein the film (253) of the second material initially has a thickness on the order of 0.2 mm or 0.3 mm. [6] Method according to any one of claims 1 to 5, wherein the mold (M) is heated when arranging the layer of the porous first material. [7] Method according to any one of claims 1 to 5, wherein the layer (251) of the porous first material is first heated before being arranged in the mold (M), the method comprising a step for transferring the heated layer (251) from the porous first material into the mold (M). [8] Method according to one of the preceding claims, wherein in the compression step by closing the mold (M) the layer (251) of the porous first material at the level of the compressed and circumferential area (Z2) is formed such that it has a connection interface (27) which is designed for connection with a corresponding structure (30) by positive locking. [9] Wall (25) manufactured using a manufacturing process according to one of the preceding claims and designed for connection with a corresponding structure (30), in particular a housing (3) of a system (1) for heating and / or ventilating and / or air conditioning an airflow for a motor vehicle, characterized by , that the wall (25) has a layer (251) of a porous first material, which has at least a first region (Z1) and a second region compressed and circumferential with respect to the first region, which is arranged at least partially at the edge of the wall (25), wherein the compressed and circumferential second region (Z2) has a film (253) of a second material.

Images