Method and apparatus for manufacturing a bladder that can be filled with a fluid

Abstract

Method (M) for producing a fluid-fillable bladder (1) comprising the steps - Forming the bladder (S1) and connecting the bladder (1) to a hose (4) through which the bladder (1) can be filled with the fluid, by welding at least one film (2,3) and the hose (4) in a molded body having a lower (11) and an upper molded part (12) to form a shell of the bladder (1) defining an interior space (6) such that the shell has a weld seam (5), and - Treating the blister or the at least one film in the molded body with heat (S2), wherein the heat has a temperature between 25 and 100 degrees Celsius.

Description

[0001] The present invention relates to a method for producing a bladder that can be filled with a fluid, a device for producing such a bladder and a corresponding bladder.

[0002] Fluid-fillable bladders are used, for example, in vehicle seats. German patent DE 103 55 519 A1 describes a seating system consisting of a seat cushion and a backrest cushion, each with an integrated bladder. The bladders are filled via a compressed air supply line from a compressed air system with a compressed air reservoir and a compressor. The air pressure in the bladders, which can be variably adjusted via the compressed air supply, allows for the desired comfort level of the seating system by creating a firmer or softer seat cushion. Bladders can also be arranged laterally, which can be dynamically controlled, for example, during cornering. Furthermore, a massage function can be provided by continuously changing the inflation pressure of the bladders.

[0003] As described, for example, in DE 10 2005 032 549 A1, such bladders are generally formed using two plastic films that are welded together at their edges to create a weld seam. However, especially when the bladders are frequently inflated and deflated, the weld seams are subject to considerable stress, which can lead to leaks requiring replacement of the bladder.

[0004] US Patent 6,392,166 B1 relates to a method for manufacturing a liquid-filled elastomeric bladder for measuring the weight of vehicle occupants, in which the bladder material is subjected to a heat treatment process prior to installation in a vehicle seat in order to quickly relieve the initial stresses that arise when filling with liquid.

[0005] EP 0 379 091 A2 relates to a method for increasing the temperature resistance of thermoformed articles made of crystallizable plastic, in which post-crystallization heat treatment is carried out after forming. This is completed by inserting a positive, dimensionally accurate, cooled mold into the heat-treated article.

[0006] DE 41 17 197 A1 relates to a process for manufacturing self-contained profiled plastic parts with cavities, in which two thermoplastic films or sheets are simultaneously clamped and each heated from the outside on one side until they are completely plasticized. The two plasticized sheets are then formed separately in a single operation and welded together under pressure without any additives. A device is used whose upper and lower forms have corresponding chamfers and / or projections, which form inwardly projecting weld beads in the weld area. An intermediate frame is arranged between the machine table and the clamping frame, which keeps the sheets spaced apart.

[0007] AT 414 090 B relates to a fluid-fillable, volume-variable body consisting of at least two superimposed films, preferably made of plastic material, welded together along at least one closed curve, preferably the circumferential edge. To reduce the stress on the film material and increase fatigue strength in such bodies, the films lie substantially parallel to each other on the side of the welded edge opposite the fluid-fillable volume and, when the body is unfilled, form an angle greater than 0° with each other on the side facing the fluid-fillable volume.

[0008] DE 10 2004 008 408 B4 relates to a seat insert, which can be used in particular for a seat in a motor vehicle or aircraft, with a gas-tight, flexible cover that at least partially encloses a volume and has an inner and an outer surface. The seat insert is also provided with a cushioning element made of open-cell soft foam, which is bonded to the inner surface of the cover. The seat insert also has at least one valve through which the amount of gas present in the volume can be regulated. To achieve an ergonomically sound and aesthetically pleasing design, the cushioning element is made of molded foam. A method for manufacturing such a seat insert is also described.

[0009] Against this background, it is an object of the present invention to provide a means of producing more robust fluid-fillable bladders.

[0010] This problem is solved by a method according to claim 1 and a device according to claim 5. The dependent claims specify embodiments.

[0011] The invention comprises a method for manufacturing a fluid-fillable bladder. Such a bladder can, in particular, be used for vehicle seats. According to the method, the bladder is formed by welding together at least one film. The film can, in particular, be made of plastic. Through welding, the film forms a shell defining an interior space, the shell having a weld seam. According to the invention, the bladder or the at least one film is additionally heat-treated within a mold. In the following, "heat" is understood to mean any temperature that deviates from normal room temperature and is specifically used to increase the robustness of the bladder.

[0012] Welding can lead to disordered polymers and / or semi-crystalline regions within the film. Treating the bubble, especially the weld seams, with heat can increase its robustness. For example, this can increase the contact areas between macromolecules and reduce the distances between them. Secondary bonds can be strengthened, and waves and wrinkles at the weld seam can be reduced.

[0013] Preferably, the molded part is preheated before the bladder is treated with heat, so that the molded part has a predetermined temperature. In this way, the heat can be applied in a targeted manner.

[0014] The step of forming the bubble by welding can be performed within the mold. Because both the welding and heat-treating steps of the bubble are carried out within the mold, fewer operator steps are required to support the process. In particular, the bubble does not need to be removed from a welding unit to be placed in the mold.

[0015] In one embodiment, the method according to the invention comprises the step of generating a vacuum in the mold body in order to draw the bubble against a surface of the mold body. The vacuum in the mold body brings the bubble's shell into contact with the heated mold body, so that heat can be transferred from the mold body to the bubble.

[0016] Alternatively or additionally, the method according to the invention can include the step of pumping a fluid into the bladder to press the bladder against a surface of the molded body. The fluid in the bladder then brings the bladder's shell into contact with the molded body.

[0017] Heat can be transferred to the bladder via the mold body and / or the fluid. This means that both the mold body and the fluid can be heated. The fluid can be, in particular, air or water.

[0018] Pre-forming of the bladder can occur by suctioning the bladder's outer shell against the surface of the mold and / or filling the bladder with a fluid while simultaneously applying heat. It is important to consider that the change in the film's shape during filling, from a two-dimensional plane to a three-dimensional curved surface, generates tensile forces. If these tensile forces are not compensated by corresponding stretching, shear forces develop towards the weld seam in the circumferential direction of the bladder. As the filling increases, these forces can lead to the formation of waves and wrinkles near the seam. These waves and wrinkles increase the risk, especially under dynamic loading, of the weld seam being overloaded and tearing. Suctioning the bladder's outer shell against the surface of the mold and / or filling the bladder with a fluid and treating the bladder with heat simplifies the film's deformation process.Stretching can therefore occur more easily, so that the tensile forces decrease.

[0019] In one embodiment, the mold body is designed as an embossing die, and the bladder or at least one film is pre-formed by closing the embossing die with a predetermined pressure. This process is comparable to deep drawing. When using an embossing die, both the upper and lower parts of the bladder are stretched in the same direction, but when the bladder is first filled with a fluid, the material is already stretched, and the part of the bladder that was essentially stretched the wrong way can fold over in the opposite direction to its curvature.

[0020] Treating the at least one film or bladder with heat can have the effect of both curing a weld seam and pre-forming the film, thereby reducing tensile forces resulting from the deformation. It is possible for the bladder to first be formed by welding in a separate device and then heat-treated in a mold. Alternatively, the at least one film can be placed unsealed into the embossing die, pre-formed by the die, and then welded within the die. Embossing and welding can also be performed in reverse order within the die. Furthermore, it is possible for the unsealed films to first be pre-formed in the die and then welded in a separate device.

[0021] The heat applied to the bubble within the mold can range from 25 to 100°C, but is particularly effective between 50 and 70°C. Especially at temperatures between 50 and 70°C, good results can be achieved with a high degree of efficiency.

[0022] In one embodiment, a higher temperature is applied to the area of ​​the bubble containing the weld seam than to an area of ​​the bubble without a weld seam. This allows for a targeted higher temperature in the weld seam area, as the material requires more time to heal there than in areas of the film that only need to be stretched.

[0023] In addition to the manufacturing process, the present invention comprises a device for producing a fluid-fillable bladder, the bladder being particularly suitable for use in vehicle seats. The device according to the invention includes means for forming the bladder by welding at least one film, for example, in the form of a welding device. This film may, in particular, be a plastic film. By welding, the film forms an interior-defining shell of the bladder, such that the shell has a weld seam. According to the invention, the device further comprises a mold for treating the bladder or the at least one film with heat.

[0024] The molded body can have a lower and an upper molded part. The means for forming the bubble by welding can comprise a first electrode ring arranged on the lower molded part and a second electrode ring arranged on the upper molded part. The two electrode rings can, in particular, be made primarily of brass.

[0025] The first and second electrode rings, which are integrated into the mold body, make it possible to form the bubble within the mold body by welding at least one film and then heat-treating it. This eliminates the need to remove the finished bubble from a separate welding unit and transfer it to a mold body for heat treatment.

[0026] The device according to the invention can include a pump for generating a vacuum in the molded body and / or a pump for pumping a fluid into the bladder. The pumping process brings the bladder's outer shell into contact with the molded body.

[0027] Furthermore, the device according to the invention can include a heat supply device for heating the molded body and / or a heat supply device for heating the fluid. Thus, both the molded body and any fluid to be pumped into the bladder can be heated.

[0028] In one embodiment, the molded body heat supply device and / or the fluid heat supply device are designed such that when treating the blister with heat, a higher temperature is applied to an area of ​​the blister containing the weld seam than to an area of ​​the blister without a weld seam. In this way, the weld seam is treated with heat particularly intensively to promote the weld healing process.

[0029] In one embodiment of the device according to the invention, the forming body is designed as an embossing die for preforming the bladder or the at least one film by closing the embossing die with a predetermined pressure. The film material can be stretched accordingly by the embossing die.

[0030] In addition, the invention comprises a fluid-fillable bladder for a vehicle seat, which was produced using the inventive method and / or with the aid of an inventive device.

[0031] It should be noted that features of the invention have been described with reference to different subject matter. In particular, some features represent an embodiment of a device and other features represent an embodiment of a method. Unless otherwise stated, the features described with reference to the method can be combined with device features and vice versa. In particular, the device includes the necessary means for carrying out the described method steps.

[0032] Further details and advantages of embodiments of the invention are explained below with reference to the figures. Fig. 1a a schematic representation of an embodiment of a bubble according to the invention in a top view; Fig. 1b a cross-sectional view through the bubble made of Fig. 1a; Fig. 2 a first embodiment of a device according to the invention; Fig. 3a a second embodiment of a device according to the invention in a perspective view; Fig. 3b a lower molded part of the in Fig. 3a device shown; Fig. 3c an upper molded part of the in Fig. 3a device shown; Fig. 3D cross-sectional view through the device Fig. 3a; Fig. 4 additional elements that make up the device Fig. 3a belong; Fig. 5 alternative elements that make up the device Fig. 3a belong; Fig. 6 an embodiment of the in Fig. 2 of the shaped body shown; Fig. 7 an embodiment of a method according to the invention; Fig. 8 an embodiment of the step forming the bubble by welding and Fig. 9 an embodiment of the step of treating the blister with heat.

[0033] In the following description, identical and equivalent elements are named with the same reference symbols unless otherwise specified.

[0034] The Fig. 1a and Fig. Figure 1b illustrates an embodiment of a bladder according to the invention for a vehicle seat. Such bladders allow, for example, comfortable adjustment of the seat in both static and dynamic ranges. Static adjustment can serve to permanently adapt the seat geometry to the user. Dynamic functions are used, for example, for massage functions and for continuously adapting the seat to the driving situation.

[0035] As the Fig. 1a and Fig. As illustrated in Figure 1b, the bubble 1 shown consists of a first film 2 and a second film 3. A tube 4 is located between these two films 2 and 3, through which the bubble 1 can be filled with a fluid. To seal the bubble 1, it has a weld seam 5. This weld seam 5 creates a fluid-tight shell from the films 2 and 3, defining an interior space 6.

[0036] The films 2 and 3 are weakened by the welding in the area of ​​the weld seam 5. Without the heat treatment of the bladder after welding as provided for in the invention, the mechanical stress during the filling process can very easily lead to breaks in the film in the area of ​​the weld seam, especially in dynamic applications. The break usually occurs from the inside out, perpendicular to the main direction of stress.

[0037] The Fig. Figure 2 shows a first embodiment of a device according to the invention for producing a bladder that can be filled with a fluid. The device 7 shown comprises means for forming the bladder 8 by welding at least one film to form a shell defining an interior space of the bladder and a mold 9 for treating the bladder with heat.

[0038] The Fig. Figure 3a illustrates a second embodiment of a device 10 according to the invention. This comprises a molded body with a lower molded part 11 and an upper molded part 12. The lower molded part 11 is further divided into Fig. 3b shown. It comprises a lower recess 13 for receiving the bladder and a recess 14 for receiving the hose 4. An electrode ring 15 for welding is arranged around the lower recess 13. The upper molded part 12 is in Fig. 3c is shown in detail. It comprises an upper recess 16 for receiving the bladder 1 and a further recess 17 for receiving the hose 4. A second electrode ring 18 is arranged around the upper recess 16. An outlet bore 19 is provided in the upper recess 16, through which air can escape or even be selectively pumped out. The lower recess 13 can also have such an outlet bore. When the upper molded part 12 with the upper recess 16 facing downwards is placed on the lower molded part 11, the following is again obtained: Fig. Situation shown in 3a.

[0039] The Fig. 3D illustrates a cross-section through the in Fig. 3a shown shaped body. As in Fig. As indicated in 3a, this is a cut that runs approximately through the middle of the molded body, thus intersecting recesses 14 and 17 as well as the outlet bore 19. Fig. Figure 3D shows that the first electrode ring 15, located in the lower molded part 11, is in close proximity to the second electrode ring 18, located in the upper molded part 12. The two electrode rings 15 and 18 can be used to weld two films together to form a bubble.

[0040] The Fig. Figure 4 illustrates a possible environment or further elements of the device 10. Fig. 3a. The lower molded part 11 is heated by a first molded part heating element 20 in the form of a heating coil. A second molded part heating element 21 in the form of a heating coil is located in the upper molded part 12. The two heating coils 20 and 21 are connected to a power supply 23 via a control element 22. A temperature measuring device 24 measures the temperature of the device 10. Based on the temperature measured by the measuring device 24, a control unit 25 regulates the heating coils 20 and 21 via the control element 22 such that a desired temperature is reached.

[0041] To ensure that the bladder 1 located in the device 10 is in contact with the surfaces of the device 10, the bladder 1 is filled with air. Various elements are provided for this purpose. A pneumatic pump 26 pumps air into a compressed air reservoir 27. This reservoir contains a heating device 28, for example, in the form of a heating coil, which is connected to a power supply 30 via a control element 29, such as a switch. The compressed air reservoir 27 also has a temperature measuring device 31. The control device 25 regularly queries the temperature measuring device 31 and, via the control element 29, switches the heating device 28 on when the temperature in the compressed air reservoir 27 falls below a first predefined threshold, and off when the temperature in the compressed air reservoir 27 exceeds a second threshold. The first threshold could, for example, be 55°C and the second threshold 65°C.This ensures that compressed air at a temperature between 55 and 65°C is maintained in the compressed air reservoir 27. Furthermore, the control unit 25 controls the pneumatic pump 26 in such a way that it only pumps compressed air into the compressed air reservoir 27 when the pressure falls below a certain threshold. The pressure information required for this can be provided, for example, by a pressure regulating valve 32.

[0042] Compressed air from the compressed air reservoir 27 is supplied to a pneumatic coupling 34 via the pressure regulating valve 32 and a shut-off valve 33. The pressure regulating valve 32 ensures that, regardless of the pressure on its inlet side, a specific outlet pressure of, for example, 400 to 500 hectopascals above atmospheric pressure is not exceeded. The pressure regulating valve 32 is in turn controlled by the control unit 25, which also controls the shut-off valve 33.

[0043] The hose 4 of the bladder 1 located in the device 10 can be connected to the pneumatic coupling 34. The control unit 25 controls the shut-off valve 33 such that the bladder 1 is inflated with heated air as soon as the hose 4 is connected to the pneumatic coupling 34. For example, an operator can activate a switch when connecting the hose 4 to the pneumatic coupling 34 to inform the control unit 25 accordingly. As soon as the hose 4 is removed from the pneumatic coupling 34, the control unit 25 closes the shut-off valve 33 again. The necessary information for this can either be provided by an operator via a push-button switch, or the control unit 25 can react to a sudden pressure drop at the pressure regulating valve 32 and then close the shut-off valve 33.

[0044] Additionally, the control unit 25 is connected to a timer 35. This timer 35 is started as soon as the bladder 1 is filled with heated air. After a predetermined time, the timer 35 emits an acoustic or visual signal, thus informing the operator that the heat treatment step is complete and that the bladder 1 can be disconnected from the pneumatic coupling 34 and removed from the device 10.

[0045] Particularly good results with a high degree of efficiency are achieved when the bladder is treated with heat for 1 to 2 minutes at a temperature of 50 to 70°C and an internal air pressure of 400 to 500 hectopascals above atmospheric pressure.

[0046] The mold body heat supply devices 20, 21 and / or the fluid heat supply devices 28 can be configured such that, when the bladder is treated with heat, a higher temperature is applied to a region of the bladder containing the weld 5 than to a region of the bladder without a weld. For example, it is possible to arrange the mold body heat supply device 20 near the first electrode ring 15 and the second mold body heat supply device 21 near the second electrode ring 18. Alternatively, the heating coils 20, 21 could be omitted, and the first and second electrode rings 15, 18 could be considered a type of mold body heat supply device. In such a configuration, the mold body would be heated primarily by the fluid pumped into the bladder.Additionally, the heat generated by the welding process would warm the lower and upper molded parts, especially near the weld seam.

[0047] Fig. Figure 5 illustrates an alternative environment for the device 10. Fig. 3a. Many of the elements shown are similar to those from Fig. 4 are identical, so they bear the same reference symbol and do not require further explanation. The in Fig. The embodiment shown in section 5 differs from the embodiment shown in section 5. Fig. 4. This is achieved not by inflating the bladder 1 via the hose 4 to bring the bladder's shell into contact with the molded body, but by creating a vacuum within the device 10 via the outlet bore 19, so that the bladder's shell is drawn against the surface of the device 10. For this purpose, a pneumatic pump 36 is provided, which pumps air out of a vacuum reservoir 37 to create a vacuum. A pressure regulating valve 38 allows the vacuum supplied at the pneumatic coupling 34 to be adjusted. The outlet bore 19 is connected to the pneumatic coupling 34 via a hose 39 to create a vacuum in the device 10.

[0048] In Fig. 6 is an embodiment of the in Fig. Figure 2 shows a mold 9 for treating the bladder with heat. The mold 40 is designed as an embossing die and comprises a lower mold part 41 and an upper mold part 42. In this embodiment, the means for forming the bladder by welding are not integrated into the mold 40. Instead, the bladder is first produced separately, then placed in the recess of the lower mold part 41, and heated and pre-shaped accordingly by closing the mold 40 with the upper mold part 42. For this purpose, the lower and upper mold parts 41 and 42 are again equipped with a mold heat supply device (not shown).

[0049] Alternatively, the at least one film from which the bubble will later be produced can first be heat-treated in the embossing die 40 to pre-shape the film material, and then the at least one film can be welded together to form a bubble. The welding can be done in a separate welding unit or in the embossing die itself.

[0050] For welding, the embossing die can be used with means for forming the bubble by welding, such as the one in Fig. The two electrode rings 15 and 18 shown in Figure 3D are included. Of course, the step of forming the bubble by welding the at least one foil in the embossing die can also be carried out before the step of treating the bubble with heat.

[0051] Fig. Figure 7 shows an embodiment of a method according to the invention. In a first step S1, a bubble 1 is formed by welding together at least one film 2, 3, in particular a film made of plastic. The at least one film 2, 3 is welded together such that the film defines an interior space 6 of the bubble 1. The film serves as a kind of shell, which has a weld seam 5. In a second step S2, the bubble 1 is heat-treated in a mold.

[0052] The Fig. Figure 8 illustrates an embodiment of step S1 from Fig. 7. First, in step S11, two films 2 and 3 are prepared. In step S12, the first of the two films 3 is placed in the lower mold part 11. A tube 4 is placed on this first film 3 (step S13), and then a second film 2 is placed on top of the first film 3 with the tube 4 on it (step S14). In step S15, the mold is then closed by placing the upper mold part 12 on the lower mold part 11. In step S16, an electrically conductive rod, also called a mandrel, is inserted into the tube and serves as a first electrode for welding the tube to the film. The first and second electrode rings 15 and 18 of the lower and upper mold parts 11 and 12 serve as the second electrode. In step S17, the hose 4 is then welded to the foils 2,3 by applying a high-frequency voltage to the mandrel as the first electrode and to the two electrode rings as the second electrode.The mandrel is then removed from the tube in step S18. In step S19, the two films 2 and 3 are welded together by applying a high-frequency voltage to the first and second electrode rings 15 and 18.

[0053] Fig. Figure 9 shows an embodiment of step S2 from Fig. 7. In step S21, the pneumatic pump 26 first generates overpressure in the compressed air reservoir 27. The compressed air is then heated there by means of a fluid heat supply device 28 (step S22). Simultaneously, in step S23, the device 10, consisting of the lower and upper molded parts 11, 12, is preheated. These steps S21 to S23 can be performed before step S1. This means that heated compressed air is already available before the two films are welded together, and the molded part is already preheated. After the bladder has been formed by welding at least one film, the hose 4 of the bladder 1 is connected to the pneumatic coupling 34 (step S24), and the bladder 1 is inflated in step S25. At the same time, the timer 35 starts running (step S26). When a predetermined time period has elapsed, a visual or audible signal is emitted (step S27).The signal indicates to the operator that the heat treatment step is complete. In step S28, the operator disconnects hose 4 from pneumatic coupling 34, opens the mold in step S29, and removes the bubble 1 in step S30. At this point, the next film (step 12) can be inserted into the lower mold 11 to produce the next bubble and subsequently heat-treat it.

[0054] The inventive method makes it possible to increase the robustness of the bladder. Specifically, this can mean that significantly more filling cycles (for example, up to 450,000 filling cycles) are achieved and the bladder's service life is considerably extended. Furthermore, functions such as massage can be implemented, which, without preconditioning the bladder by the described heat treatment, are subject to a high risk of failure. The description of the figures is purely illustrative and not to be understood as limiting. Many modifications can be made to the illustrated embodiments without departing from the scope of protection as defined in the appended claims. The features of different embodiments can be combined with one another to provide further embodiments optimized for the intended application. For example, the electrode rings of the second embodiment can also be incorporated into the [figure / structure] shown in [figure / figure]. Fig.The embossing die shown in section 6 is integrated, so that this embossing die includes means for forming the bubble by welding. Reference symbol list 1 bladder 2 first slide 3 second slide 4 hoses 5 weld seam 6 Interior 7 first embodiment of a device according to the invention 8 methods for forming the blister by welding 9 Molded parts 10 second embodiment of a device according to the invention 11 lower molded part 12 upper molded part 13 lower hollow 14 recess 15 first electrode ring 16 upper trough 17 recess 18 second electrode ring 19 Outlet bore 20 first molded body heat supply device 21 second molded body heat supply device 22 Control element 23 Power supply 24 Temperature measuring device 25 Control unit 26 Pneumatic pump 27 compressed air tanks 28 Fluid heat supply device 29 Control element 30 Power supply 31 Temperature measuring device 32 Pressure regulating valve 33 Shut-off valve 34 Pneumatic coupling 35 o'clock 36 Pneumatic pump 37 Vacuum containers 38 Pressure regulating valve 39 hose 40 shaped bodies in the form of an embossing mold 41 lower molded part 42 upper molded part S1 Formation of the blister by welding S2 Treating the blister in a mold with heat S11 Providing two slides S12 Placing a first film on the lower molded part S13 Arranging the hose on the first slide S14 Arranging a second film on top of the first film and the hose S15 Positioning the upper molded part on the lower molded part S16 Arranging a mandrel in the hose S17 Welding the hose to the two films S18 Removing the mandrel from the hose S19 Welding the foils together S21 Generating compressed air in the compressed air tank S22 Heating the compressed air S23 Heating the molded body S24 Connecting the bladder hose to the pneumatic coupling S25 Pumping air into the bladder S26 Starting the clock S27 Output a signal S28 Disconnecting the hose from the pneumatic coupling S29 Opening the mold body S30 Removing the bubble from the mold body

Claims

[1] Method (M) for producing a fluid-fillable bladder (1) comprising the steps - Forming the bladder (S1) and connecting the bladder (1) to a hose (4) through which the bladder (1) can be filled with the fluid, by welding at least one film (2,3) and the hose (4) in a molded body having a lower (11) and an upper molded part (12) to form a shell of the bladder (1) defining an interior space (6) such that the shell has a weld seam (5), and - Treating the blister or the at least one film in the molded body with heat (S2), wherein the heat has a temperature between 25 and 100 degrees Celsius. [2] Method according to claim 1, comprising the step of generating a vacuum in the mold body to draw the bubble against a surface of the mold body. [3] Method according to any of the preceding claims, comprising the step of pumping a fluid into the bladder (S25) to press the bladder against a surface of the molded body. [4] Method according to any of the preceding claims, wherein the heat has a temperature between 50 and 70 degrees Celsius. [5] Device (7,10) for producing a bladder (1) that can be filled with a fluid, comprising - Means for forming the bladder (8, 15, 18) and connecting the bladder (1) to a tube (4) through which the bladder (1) can be filled with the fluid, by welding at least one film and the tube (4) together to form an interior-defining shell of the bladder (1) such that the shell has a weld seam, and - a molded body (9, 11, 12, 40) having a lower (11) and an upper molded part (12) for treating the blister (1) or the at least one film with heat, wherein the molded body comprises the means for forming the blister (1). [6] Device according to claim 5, comprising means for forming the bubble (1) by welding a first electrode ring (15) arranged on the lower mold part (11) and a second electrode ring (18) arranged on the upper mold part (12). [7] Device according to claim 5 or 6, comprising a mold body heat supply device (20, 21) for heating the mold body and / or a fluid heat supply device (28) for heating a fluid. [8] Device according to claim 7, wherein the molded body heat supply device (20, 21) and / or the fluid heat supply device (28) are designed such that when treating the bladder (1) with heat, heat with a higher temperature is applied in an area of ​​the bladder (1) in which the weld seam (5) is located than in an area of ​​the bladder (1) without a weld seam. [9] Device according to claim 5, wherein the mold body is designed as an embossing die (40) for preforming the bubble (1) or the at least one film by closing the embossing die with a predetermined pressure.

Images