DE102010008263A1 - Pressure tank for accommodating e.g. water in sanitary technology, has plastic container designed as injection molding part with layer arranged at interior periphery of container and/or external periphery of container - Google Patents

Abstract

The tank (1) has a plastic container (3), which forms a cavity (2) e.g. cylindrical cavity, and is locked in a pressure tight manner. The plastic container is designed as an injection molding part with a layer (5) arranged at the interior periphery (4) of the container and/or external periphery of the container. The container consists of transparent or semi-transparent plastic. The layer is made of a metal foil e.g. aluminum foil or stainless steel film, a plastic film with a layer of thermoplastic, fabric and/or multi-ply fabric made of metal fibers and/or glass fibers and/or carbon fibers. An independent claim is also included for a method for manufacturing a pressure tank.

Description

The invention relates to a pressure vessel, in detail with the features of the preamble of claim 1.

The invention further relates to a method for producing such a pressure vessel.

In the context of the invention, a pressure vessel is understood to mean a vessel which is characterized by walls surrounding a cavity and, under predefined operating conditions, at least temporarily exposed to a pressure difference, usually an increased internal pressure. The pressure applied in the cavity which can be written on by the cavity is greater or smaller than the ambient pressure. Pressure vessels are used to hold media in the form of gases, fluid media or solids or mixtures thereof and are versatile in terms of their functions. In this case, the medium taken up in the pressure vessel can already be introduced under pressure into this or else the pressure can only be exerted subsequently on demand temporarily. The pressure vessels can act as storage containers, pressure accumulators, heat accumulators, filter housings, valve housings, pump housings, meter housings, procedural containers.

In many applications nowadays metal components are increasingly being replaced by plastic components. This is especially true in the field of sanitary and heating technology, as well as the automotive industry. In particular, pressure-carrying components are designed as injection-molded components. The selection of the respective material / material is made on the basis of the requirements. Frequently used thermoplastics are polyethylene, polypropylene, polyacetal, polyphenyl ether, polysulfone, polyamide, polyphthalamide, polyethersulfone with and without reinforcing materials. Since the media carried or located in the pressure-bearing components have a strong influence on the aging behavior of the materials and the media are often characterized by higher temperatures and pressure difference fluctuations, it is necessary to use high-quality and characterized by increased strength and wear resistance for prolonged use materials, which is why often high quality polymers are used.

A major major disadvantage of all plastics used in comparison to metallic materials, however, is the relatively low modulus of elasticity and the higher creep under permanent load, that is, constant pressure load. The lower modulus of elasticity causes above all a deformation of the components under pressure load. This is very negative in particular at connecting or sealing points or between moving components, since leaks may occur here due to the deformation. To counteract this problem, often fiber-reinforced plastics, usually with glass fiber reinforcement, for example PA66 with 30% glass fibers used in heating technology. The problem with this solution, however, is that the reinforcement, ie the increase in modulus of elasticity, takes place predominantly in the fiber direction and thus the modulus of elasticity depends on the direction of filling of the polymer Components in the injection molding process is. Another important problem is the weld lines. Since pressure vessels generally require connection areas, the plastic melt inevitably has to flow around the tool core during filling, which subsequently forms the opening of the component. Thus inevitably arises around this connection of the pressure vessel around an unfavorable fiber orientation and a weld line. This represents a significant weak point of the connection area, since connection areas are particularly burdened by external influences such as connection forces, assembly forces, etc.

If pressure vessels are cylindrical, the cylinder often has to be filled longitudinally along the cylinder axis in the injection molding process so that it does not become out of round in reinforced plastic and no unfavorable weld line is formed. This leads to a fiber orientation transverse to the actual loading direction of the cylinder wall. However, the resulting gain and strength in the main load direction is very unfavorable and is often insufficient.

On the other hand, a high fiber reinforcement leads to an increase in the brittleness of the material and a drastic reduction in the compressive strain. However, a brittle and sudden failure behavior is undesirable for pressurized components that incorporate fluids, such as sanitary technology, because replacement is no longer possible prior to the failure of a component that may flood the entire dwelling. With slow ductile failure it drips first and the damage can be repaired even before the total failure.

The invention is therefore based on the object to provide a cost-effective pressure vessel and to improve the bursting pressure and the deformation under pressurization and to use the materials used for this purpose ideal and as simple and inexpensive to manufacture.

The solution according to the invention is characterized by the features of claims 1 and 10. Advantageous embodiments are described in the subclaims.

A pressure vessel according to the invention comprising a plastic container which forms a cavity and can be closed in a pressure-tight manner is characterized in that the plastic container is designed as an injection molded part with at least one layer, in particular film, arranged on its inner and / or outer circumference.

According to the invention, the object is achieved by the injection molding or at least partially encapsulating a layer, in particular film, in order to reinforce the pressure-loadable wall and to minimize the deformation of the container. The design as a composite component allows the support and absorption of greater pressure forces compared to pure plastic containers. Due to the targeted arrangement of the at least one film or even more films, individual regions of the pressure vessel can furthermore be purposefully reinforced.

A layer is understood as meaning thin, flat structures which are characterized by a significantly greater extent in the length and width direction than in the vertical direction. These are preferably formed by films, which may be present in various designs. These are preferably designed in the form of finished rolling products or drawn sheet-like structures.

However, this layer can also comprise at least one woven fabric, scrim, grid or other network structure or a prepreg, that is to say a fiber fabric preimpregnated with thermoplastic, in particular glass fiber fabric. The choice of the training of the situation, in particular structure also allows the targeted influence on the increase in strength and the direction of reinforcement in different directions of loading.

• – Metallfolie, insbesondere Aluminiumfolie oder Edelstahlfolie
• – Kunststofffolie, insbesondere Kunststofffolie mit mindestens einer Schicht des gleichen thermoplastischen Kunststoffs, wie der hinterspritzte Kunststoff
• – Gewebe aus Metall oder Glasfasern oder Kohlefasern
• – Gelege aus Metall oder Glasfasern oder Kohlefasern
• – Gitter- und/oder Netzstruktur aus Kunststoff oder Metall
• – Prepreg, insbesondere mit thermoplastischem Kunststoff vorimprägniertes Fasergewebe, insbesondere Glasfasergewebe,

With regard to the materials used and their construction, the individual layer, in particular foil, is designed as one of the following embodiments or a combination thereof:

• - Metal foil, in particular aluminum foil or stainless steel foil
• - Plastic film, in particular plastic film with at least one layer of the same thermoplastic material, as the back-injected plastic
• - Fabric of metal or glass fibers or carbon fibers
• - Clutches of metal or glass fibers or carbon fibers
• - Grid and / or network structure made of plastic or metal
• Prepreg, in particular fiber fabric preimpregnated with thermoplastic, in particular glass fiber fabric,

The training is carried out in one or more layers, wherein the individual above-mentioned possible layer structures in turn can be coated or functionalized by other surfaces or additives. Advantageously, magnetic or functionalized films can also be used.

In a particularly advantageous embodiment, metal foils, in particular aluminum foils or stainless steel foils are used. These are characterized by a lower creep and higher modulus of elasticity of the plastic of the plastic container, so that the strength of such a compound is very stable. These also have good conformability. The metal foil with a thickness in the range of 50 .mu.m to 1000 .mu.m, preferably 100 .mu.m to 400 .mu.m, particularly preferably 100 .mu.m to 200 .mu.m load unexpectedly well handled punching, in a mold, in particular an injection mold, insert and deform medium injection pressure. On the finished component unexpectedly no sharp edges or edged ends of the film are formed. This also not in areas of overlaps. The realizable peak pressure in the injection molding tool in the injection molding process of 100-2500 bar, preferably 500-2000 bar, more preferably 800-1500 bar is sufficient to deform the metal foil.

The use of an electrically conductive metal foil may additionally serve for the temperature control of the medium in the pressure vessel. Also, metal foils are ideal for training and take on other functions, such as the formation of screw holes for sheet metal or Tapping screws. This screw receptacle can then transmit much higher forces than conventional compounds of a screw in plastic due to the plastic-metal compound. On the insertion of mechanically machined and therefore expensive metal inserts with thread can be dispensed with.

A plastic film may be a monolayer or multilayer film. Preferably, the plastic film is characterized in that at least one side of the film consists of the same thermoplastic polymer as the back-injected plastic and / or is hidden. A stretched plastic film has a higher modulus of elasticity and higher strength compared to the same injection molded unreinforced plastic. Furthermore, a plastic film may have a sealing effect on cracks in the injection-molded plastic and prevent a sudden failure, since an unreinforced plastic film has a very high elongation at break. Furthermore, with a reinforced plastic film, it is possible to make positive use of the plastic film's modulus of elasticity depending on the reinforcing material and the production process.

The training as a fabric, scrim or grid or network structures allows the targeted setting of preferred directions of individual properties of the plastic container reinforcing layer.

In a particularly advantageous embodiment, the layer, in particular film has a thickness in the range of 10 .mu.m to 1000 .mu.m, preferably 50 .mu.m to 600 .mu.m, more preferably 100 .mu.m to 200 .mu.m.

The semifinished product used to form the layer, in particular film on the outer and / or inner circumference, is flexible, easy to handle and easily deformable in this thickness range and thereby permits optimum adaptation of its shape to that of the plastic container before and / or during the process of back injection and optionally selectively desired further deformations. By choosing the suitable material of the films and their thickness of the reinforcing effect of the wall of the pressure vessel can be selectively influenced locally and adjusted.

Such layers, in particular films as semi-finished are windable, can be easily rolled up and down, additionally processed, in particular coated. Further, since these are easily brought into the flat state, they can be easily cut or punched.

The pressure vessel is characterized by at least one, preferably a plurality of layers, in particular films. These can be selectively arranged with regard to their position and thus positioned at weak points. The connection with each other can take place cohesively and / or positively and / or non-positively.

The arrangement of the layer, in particular film can be done on the inner circumference, outer circumference or both.

The layer, in particular foil, is in the deformed state in the final production state of the pressure vessel. This can be fixed in different ways. In a first particularly advantageous embodiment of the plastic container is connected at its inner and / or outer periphery with the at least one layer, in particular film cohesively to form a boundary layer in the joining region. The material bond is formed such that the boundary layer has a thickness in the range of 5 .mu.m to 100 .mu.m, preferably 10 .mu.m to 50 .mu.m, particularly preferably 10 .mu.m to 25 .mu.m. These boundary layer thicknesses ensure not only a high strength but also the tightness of the connection. The boundary layer also serves to reduce or reduce stress, or stress peaks in the bond between the layer, in particular film with a comparatively high modulus of elasticity and low coefficient of thermal expansion in the reinforcing layers, which include the materials metal, glass fibers or carbon fibers and the degradation, or reduction of stresses, or voltage peaks on the injection-molded plastic container. The reduction or reduction of stresses or stress peaks on the injection-molded plastic container under load, for example, faster, changing pressure load in the plastic container is another task of the boundary layer.

In an advantageous embodiment, the boundary layer is formed from at least one thermoplastic or one thermoplastic partially crosslinking or one crosslinking adhesive system. Adhesive system: Advantages: • thermoplastic good to activate in the injection molding process, reflowable, ductile • thermoplastic partially crosslinking good to activate in the injection molding process, low creep, ductile • networking good to activate in the injection molding process, high strength, very low creep even at high temperatures

Due to the material connection, the different components - plastic container and layer, in particular film with respect to their position firmly defined, so that in the installed position, the areas of increased strength and preferred direction are also fixed. The material connection over the entire surface further enables a pressure and liquid-tight design of the connection between the plastic container and the layer, as well as a good distribution of the forces caused by a load from the plastic container into the surface of the layer, in particular film.

In a further embodiment of the plastic container may additionally or alternatively be positively connected at its inner and / or outer periphery with the at least one layer, in particular film. The in addition to the cohesive connection executed positive connection offers the advantage of relieving the material bond. The positive connection can be specifically designed and aligned and allows the targeted introduction of force and optionally deflection.

The plastic container advantageously consists of at least one of the following materials: a polymer or a combination of polymers, in particular Plastic: Advantages: Polycarbonate + acrylonitrile butadiene styrene (PC / ABS) inexpensive, tough, transparent • Polyamides (PA) Polyphthalamide (PPA) resistant to chemicals, high heat resistance, tough, good friction and sealing behavior comparatively inexpensive • polycarbonate (PC) transparent and tough, inexpensive • Polyethylene (PE) Polypropylene (PP) chemical resistant, inexpensive, low water absorption • polyacetal (POM) unreinforced comparatively higher modulus of elasticity, good friction and sealing behavior, cost-effective Polysulfone (PSU) Polyethersulfone (PES or PESU) Resistant to chlorinated water high glass transition temperature transparent Polyphenylene sulfide (PPS) good chemical resistance, high modulus of elasticity, resistant to hydrolysis, high glass transition temperature Polyethersulfone (PPSU) good chemical resistance low water absorption, high glass transition temperature, very good creep internal pressure behavior, transparent, stress crack resistant Polyphenylene ether (PPE or PPO) Hydrolysis stable, low water absorption, relatively inexpensive

In an advantageous embodiment, the plastic container is formed from a transparent or semi-transparent injection-molded plastic. This offers the possibility of a visual condition detection for the medium located in the interior of the pressure vessel. In this case, a layer, in particular the film, must likewise be transparent or semitransparent or have a non-transparent or non-semitransparent layer, in particular recesses corresponding to the film. The recesses can be easily and inexpensively, for example, by punching, bring in the plane state of the film.

An advantageous embodiment further consists of arranging and forming the end regions of a layer, in particular foil, in such a way that they overlap one another and are connected to one another in a form-fitting and / or materially bonded manner. As a result, the strength of such a gain is increased again.

• – Bereitstellung zumindest einer Lage, insbesondere Folie;
• – Bereitstellung eines Formgebungswerkzeuges zur Ausbildung des Kunststoffgehäuses;
• – Hinter- oder Umspritzen/Vergießen der zumindest einen Lage, insbesondere Folie unter Druck im Formgebungswerkzeug durch Gießen, insbesondere Spritzgießen.

The inventive method for producing a pressure vessel, in particular pressure vessel according to one of claims 1 to 9, characterized by the following features:

• - providing at least one layer, in particular film;
• - Providing a shaping tool for forming the plastic housing;
• - Back- or encapsulation / potting the at least one layer, in particular film under pressure in the forming tool by casting, in particular injection molding.

According to the invention thus the problem of undesirable deformation of the outer periphery of the container due to pressure, by rear or overmolding a layer, in particular film to form the plastic container is achieved. An essential feature of the situation, in particular film is that this is windable and simply rolled up and unrolled, simply coated and can be brought in the flat state in the desired, the development corresponding shape, that is tailored or stamped.

An advantage of the method is to mention that the position, in particular film in the injection molding process to the outer and / or the inner contour of the mold, which forms, for example, a circular cylindrical contour, adapts, d. H. for example, the diameter of the circular cylindrical contour with changing the overlapping region of the layer, in particular film adapts. Thus, fit and Masstoleranzprobleme are avoided, which arise in an assembly when the shaping of the reinforcing layer, in particular film and the shape of the injection-molded plastic container is done in two process steps. The mounting of a film in claimed thin thickness range is hardly possible due to the high flexibility of the film.

The molding tool for the plastic container is a casting tool, in particular injection molding tool. In principle, it is possible to differentiate between the shaping of the layer, in particular the film first and only within the injection molding tool and a preforming outside and subsequent further shaping within the injection molding tool.

According to the invention, according to a first embodiment, an initially flat film with a significantly higher modulus of elasticity, higher strength and / or lower creep is placed as highly reinforced thermoplastic in a molding tool for the plastic container, in particular injection molding tool and injected behind or back-molded to form the plastic sleeve. In this injection molding process, the metal foil and / or the reinforcing element is positioned and / or deformed by the injection pressure of the plastic mass in the desired manner.

In a particularly advantageous embodiment, in each case the sides of the layer, in particular film, which are connected to the plastic sleeve, coated with an adhesion promoter, which is attached to the joining surface provided for joining, applied and under the conditions of the injection molding process a material connection between the forming Plastic part and the situation generated. Due to the suitable choice of the adhesion promoter, in particular the nature and quantity and the size of the swept surface, the strength of the producible material bond between the layer and the plastic container can be influenced and adjusted.

In this particularly advantageous embodiment, the shaping of the at least one layer, in particular foil at least partially by the pressure during the injection molding process, in particular injection pressure, preferably completely. This offers the possibility of a simple and quick production in only one step and avoids complex additional procedures and the requirement of appropriate Halteeinrichtugen on the mold.

In an advantageous sub-variant, part of the deformation of the layer, in particular the film, is produced by relative movements of or parts of the forming tool. In this case, for example, the closing of the mold already cause a deformation of the layer, in particular foil. Furthermore, deformations may also occur during the casting process by relative movement of the forming tool. These can be moving tools or even tool components during the closing movement of the tool. By moving tool components and movements during the filling process can be generated with the plastic melt.

The use of even layers, in particular films as a semi-finished product is particularly easy during transport and handling. It can simply be rolled up, unrolled, coated and cut in width and length. Are further breakthroughs, holes or other recesses necessary, these can be easily punched in a flat state.

In a second embodiment, it is also possible to pre-form the at least one layer, in particular foil, prior to positioning in the forming tool, for example into rolls. In this case, the introduction into the molding tool for the plastic container can be simplified and it is possible to form additional functional elements that lie outside the overmolded area.

In an advantageous development, the at least one layer, in particular foil, is positioned in such a way that at least one resulting weld line is covered on the resulting plastic container, whereby the strength is increased.

For the most accurate position fixing, the at least one layer can be positioned in the forming tool and fixed by means of holding devices.

In a further development, it can be provided that the shaping process for the plastic container is carried out in such a way that several individual layers, in particular films, are used and these are formed before or during the shaping process in such a way that at least two layers, in particular films, are joined together. This compound also serves to increase the strength.

In order to relieve the material bond, in an advantageous embodiment, the at least one layer, in particular film, can have recesses which form positive-locking connections with the resulting plastic container during potting. This form-fitting can be specifically designed and aligned and allows the targeted application of force and, if necessary, deflection.

In an advantageous further development, the at least one layer can have recesses which, during casting, form positive connections with the resulting plastic container and / or different end regions of the same layer or with at least one further, d. H. train another situation. The positive connection is generated in a single process step at the same time as the production of the plastic container.

A further advantageous embodiment is characterized in that at least one layer is back-injected to form a plastic-free projection and the supernatant is designed and arranged such that it is suitable to take on a further function, in particular to be connected to a further component. In this case, the supernatant force, form or cohesively with the other component by taking over other functions, such as ensuring a seal are connected. In this further component may be the lid for closing the cavity. The connection is then preferably pressure and liquid-tight and in the simplest case by material bond taking advantage of the layer material and / or additional adhesion promoter.

For simultaneous shaping of connections to the pressure vessel, the at least one layer in the not yet injected state preferably has at least one recess which is positioned in the forming tool such that a connection to the plastic container is formed in the recess in the forming tool when the plastic container is produced, in particular poured out ,

The solution according to the invention is not limited to a specific container shape. In an advantageous embodiment, however, the pressure vessel is cylindrical. Also conceivable are variants with polygonal cross-section, wherein the transitions at the corner regions are preferably rounded in order to keep the tension of the individual layer as small as possible.

The solution according to the invention is explained below with reference to figures. It details the following:

1a to 1c show, by way of example, different embodiments of a sealable pressure vessel designed according to the invention in the unclosed state;

2a illustrates the formation of an overlap of the end portions of a layer in the preformed state;

2 B illustrates the formation of an overlap of the end portions of a layer in the final production state of the pressure vessel;

3a illustrates the arrangement of the end portions of a layer in the state of insertion into the forming tool;

3b illustrates the formation of a positive connection between the end regions in the final production state of the pressure vessel;

4 shows on the basis of a section of a sectional view through the wall of the pressure vessel a positive connection between plastic container and layer;

5 shows an embodiment of a closable pressure vessel with a port in the unlocked state;

6 illustrates the sequence of a method according to the invention on the basis of a signal flow diagram;

7a and 7b illustrate embodiments of the pressure vessel with projection of the situation relative to the plastic container for forming connections with connection components, in particular a cover.

The 1a to 1c exemplify the basic structure and the basic function of particularly advantageous inventively executed pressure vessel 1 in different versions. The single pressure vessel 1 includes one, a cavity 2 forming plastic container 3 , which is formed as an injection molded part and over at least a portion of the inner and / or outer periphery with at least one layer 5 connected is. The single location 5 can be carried out in one or more layers. This is in an advantageous embodiment of at least one film in the form of a metal foil 21 formed, which with the plastic container 3 under construction of the unit pressure vessel 1 connected is. The connection is made in a particularly advantageous embodiment pressure and liquid-tight by material bond to form a boundary layer 6 in the joining area 7 of metal foil 21 and plastic containers 3 , The pressure vessel 1 is preferably cylindrical with respect to a longitudinal axis L and has at least one closable opening 23 on. Conceivable, however, are other geometries, the individual pressure vessel 1 can also be characterized by cross-sectional changes in the longitudinal and transverse directions. With regard to the possible configurations of pressurizable cavities are also no restrictions. Preferably, however, geometries are selected to which the layers are optimally adaptable freely of sharp-edged direction changes in terms of their shape.

The 1a illustrates in schematic simplified representation of a first embodiment of an inventive pressure vessel 1 in idealized formation of the cavity in the form of a cylindrical cavity 2 , In the first embodiment is at least a partial area, preferably the entire inner circumference 4 of the cavity 2 with at least one metal foil 21 connected. The metal foil 21 forms in this embodiment due to the arrangement in the cavity 2 in the plastic container 3 an insert 8th from a metallic material, which may be formed in one or more parts and the material fit with the plastic container 3 connected is. The cohesive connection is preferably carried out over the entire plastic container 3 directed surface 22 the metal foil 21 , This is between the use 8th forming metal foil 5 and the plastic container 3 an adhesive 9 provided, which under the process conditions of injection molding in training of the plastic container 3 by Um- or injection molding around the metal foil 5 the material bond with the formation of a boundary layer 6 causes. The joining area 7 preferably extends over the entire of the metal foil 21 to the plastic container 3 directed surface. The in the cavity 2 facing surface 24 the metal foil 21 forms the surface 10 the cavity 2 surrounding wall, which may be provided with additional surface structures for the purpose of performing additional functions.

The process parameters in injection molding are different for the respective thermoplastics, according to the usual parameters to choose according to the manufacturer. For polyamide PA66 with glass fiber reinforcement, for example, a mold temperature of 80 to 120 ° C and a melt temperature of 280 to 330 ° C is to be selected. The injection pressure is in the process in a range of 100 to 2500 bar, preferably 500 to 2000 bar, more preferably 900 to 1500 bar. The emphasis is to be selected with 60 to 70% of said peak pressure. For forming a metal foil, the emphasis is preferably the same size as the injection pressure. Particularly preferably, the holding pressure is 100 to 150% of the injection pressure.

Opposite the execution in 1a clarifies the 1b a second embodiment with at least one of a metal foil 21 educated situation 5 in the area of the outer circumference 11 of the plastic container 3 , This is here designed and arranged such that it has the outer circumference 11 of the plastic container 3 at least partially, preferably completely covered. Again, the connection is preferably made by material connection on to the plastic container 3 directed surface 22 the metal foil 21 applied adhesive 9 , which is chosen such that this at least during the back-injection of the metal foil 21 is activated.

The 1c shows a combination of the variants according to the 1a and 1b with each arrangement of at least one layer 5a in the form of a metal foil 21a in the area of the inner circumference 4 and 5b in the form of the metal foil 21b in the area of the outer circumference 11 of the plastic container 3 ,

Preferably, in the in the 1a and 1b illustrated embodiments a location 5 in one piece with complete enclosure of the inner or outer periphery of the plastic container 3 by guiding the metal foil 21 formed in the circumferential direction about the longitudinal axis L. In this case, the circumferentially facing each other end areas 13.1 . 13.2 either on push 25 how in detail X in 1a illustrated by way of example or in a particularly advantageous embodiment to form a cover, as in 1b exemplified, arranged. This overlap is with 12 designated. This is the metal foil 21 in terms of their base area to choose such that it is suitable, the overlap 12 train.

The 2a and 2 B illustrate exemplified an execution of an overlap 12 , The 2a illustrates the metal foil 21 in the preformed version before the back injection. The later to the plastic container 3 directed surface 22 forms the inner circumference of the preformed contour, which in this form in a shaping tool for the formation of the plastic container 1 can be inserted, the area 24 from the forming tool is to support such that the metal foil 21 remains after the back injection in the approximately cylindrical shape. This is the metal foil 21 rolled up in the illustrated case, so that the end portions 13.1 and 13.2 partially overlap, that is partially superimposed. The overlap area 12 is preferably in the range of 1 ° to 360 ° relative to the angle of the cylinder circle of the pressure vessel. It is also a double or multiple winding conceivable.

In contrast, illustrates the 2 B the formation of the overlap area 12 on the final product pressure vessel 1 after the back injection. The execution in the 2 B corresponds to an embodiment according to the 1b with arrangement of the metal foil 5 on the outer circumference 11 the plastic receptacle. It is recognizable that at the end areas 13.1 and 13.2 due to the injection molding also a deformation has taken place to the cylindrical contour of the outer periphery of the pressure vessel 1 to maintain, which by the surface 24 the metal foil 21 is writable. In the case shown, this is the outer end region 13.2 which is the other end area 13.1 in 2a on the outer circumference of the thus preformed metal foil 21 Covered, circumferentially flush with respect to its surface to the surface of the other end portion 13.1 then executed and the end area 13.1 is located at, the inner circumference of the formed metal foil 21 characterizing area 22 at.

In a particularly advantageous further development in 3a and 3b it is envisaged the process parameters in the manufacture of the plastic housing 3 in particular to use the injection pressure at the same time to the end areas 13.1 . 13.2 the single metal foil 21 to connect form-fitting with each other. 3a illustrates in a section of a sectional view, the support of circumferentially facing each other end regions 13.1 . 13.2 the metal foil 21 on the forming tool 14 , This is indicated by the metal foil 21 recesses 15 on, which can be designed in various ways. These recesses 15 are at a distance at an end area, here the end area 13.2 arranged. This end portion is the end portion attached to the plastic container produced by injection molding 3 opposite side of the metal foil 21 reaches the concern by this the end area 13.1 covered. This is the end area 13.1 through the plastic film on the side of the metal foil 21 which of the area 22 is described, acting pressure due to the injection molding in the recess 15 pushed. For this purpose, a shaping tool is provided during the molding, which is designed and arranged such that the metal foil 21 stabilized and supported in their position, wherein in the region of the recesses 15 on the forming tool recesses 16 are provided, which are the negative mold for the desired positive connection between the end regions 13.1 . 13.2 the metal foil 21 form. This design allows a stable and sealed Endbereichsausführung, which in 3b after removal from the forming tool 14 is shown. The form fit 17 is due to penetration of the end area 13.1 into the recess 15 of the end area 13.2 generated. The variant shown here shows a very good fit in the area of the film with each other and the injection-molded plastic container. A comparable variant is also with only one recess ( 16 ) in the forming tool in the region of the positioned overlap of the films without recess on one of the film possible.

It is understood that in the in the 2a . 2 B and 3a . 3b illustrated embodiments, the gain can also be formed by a plurality of individual, arbitrarily arranged layers. These may preferably in the circumferential direction and / or longitudinal direction to form overlaps 12 , which are formed by end regions of different layers. The number of joints increases as a function of their arrangement in the circumferential direction and / or longitudinal direction of the pressure vessel 1 and their number considerably.

In an advantageous further development, it is provided that the individual layer 5 , Particularly advantageously, the single metal foil 21 either only by positive engagement or a combined form and material connection with the plastic container 3 connected is. This is indicated by the metal foil 21 recesses 18 on, which can be designed as breakthroughs or blind recesses and in the injection molding compound in the back casting of the metal foil 21 under formation of positive locking elements 19 presses. The 4 illustrates a section of the wall of the finished product of the pressure vessel 1 with such a positive connection element 19 at the plastic receptacle and the engagement in the recesses designed as openings 18 on the metal foil 21 in sectional view.

The 5 illustrates a further development of the inventive design of a pressure vessel 1 in which at least one connection 20 is provided. This is the metal foil 21 , which here in the particularly advantageous embodiment according to 1b on the outer circumference 11 of the plastic container 3 is arranged with recesses 18 provided in the form of breakthroughs and the metal foil 21 is positioned in the forming tool such that the connection area 20 to the cylindrical body, which now through the metal foil 21 is supported, can be formed in plastic. The connection shown in the figure 20 for connection to the cavity 2 a pressure vessel 1 with a reinforcing layer is only by prototyping in training of the plastic container 3 self-producible, since there is no possibility of retrofitting a reinforcing layer and no possibility of subsequent connection. The connection 20 can be designed differently and aligned in different directions. In particular, the connection 20 formed in the form of a pipe in the form of a Elypse on the inside, what the voltages in the terminal 20 to the pressure vessel 1 reduced.

The 6 illustrates by way of example with reference to a signal flow diagram, the method steps for producing a pressure vessel according to the invention 1 , In this case, the provision of at least one layer takes place in a first method step VA 5 , in particular metal foil 21 for predefined thicknesses in the range from 50 to 1000 μm, preferably 100 to 400 μm, particularly preferably 100 to 200 μm. In method step VB, the provision of a shaping tool takes place 14 for the formation of the plastic container 21 while in the process step VC the shaping of the metal foil 21 as well as the design and shape of the plastic container 3 he follows. This corresponds to method step VD. Preferably, the location 5 , in particular metal foil 21 already preformed, that is rolled up into a cylindrical element, so that here already the metal foil 21 in the preformed state in the forming tool 14 is inserted and positioned so that this after injection molding on the outer circumference or inner circumference of the respective plastic container 3 is arranged. The shaping then takes place as preforming and not under the influence of the injection molding compound.

In a particularly advantageous embodiment, the shaping takes place as far as possible during the said process.

The 7a and 7b exemplify a further advantageous embodiment with a back injection at least one layer 5 , in particular metal foil 21 while maintaining a supernatant 26 in a section of an axial section after production of the plastic container 3 in the forming tool. The connection of the metal foil 21 with the plastic container 3 takes place analogously as described in the aforementioned figures. The supernatant 26 can also use adhesion promoter 9 be coated, but not mandatory. This supernatant 26 can according to the formation of the individual layers for connection to other Baurteilen, in particular a cover 27 to close the opening 23 be used. The connection 28 between supernatant 26 and lid 27 can be done non-positively, positively and / or cohesively. Preferably, the connection is made by material adhesion due to the heating of the layer in the supernatant region after prior application of adhesion promoter or adhesive. The cohesive connection establishes a media-tight connection. The supernatant can also take on other functions. For example, a metallic tab can be formed, which serves for the positive connection to another component.

The following sentences constitute further aspects of the invention and are part of the description and not claims.

Sentences:

• 1. Method for producing a pressure vessel ( 1 ), comprising one, a cavity ( 2 ) forming and pressure-tight closable plastic container ( 3 ), characterized by the following features: - providing at least one layer ( 5 . 5a . 5b ), in particular a film; - provision of a shaping tool ( 14 ) for forming the plastic container ( 3 ); Behind or overmolding / casting of the at least one layer ( 5 . 5a . 5b ), in particular film under pressure in the forming tool ( 14 ) by casting, in particular injection molding.
• 2. Procedure according to sentence 1 , characterized in that the at least one layer ( 5 . 5a . 5b ) before or during the injection molding process by moving elements in the forming tool ( 14 ), in particular injection molding tool is formed.
• 3. Method according to one of the sentences 1 to 2, characterized in that the individual layer ( 5 . 5a . 5b ) is positioned such that at least one resulting weld line on the plastic container ( 3 ) is covered.

LIST OF REFERENCE NUMBERS

1

pressure vessel

2

cavity

3

Plastic containers

4

inner circumference

5, 5a, 5b

location

6

interface

7

joining area

8th

commitment

9

adhesives

10

surface

11

outer periphery

12

overlap

13.1, 13.2

end

14

shaping tool

15

recess

16

recess

17

form-fit

18

recess

19

Form-fitting element

20

connection

21, 21a, 21b

metal foil

22

area

23

opening

24

area

25

shock

26

Got over

27

cover

28

connection

VA-VD

steps

L

longitudinal axis

Claims (17)

Pressure vessel ( 1 ), comprising one, a cavity ( 2 ) forming and pressure-tight closable plastic container ( 3 ), characterized in that the plastic container ( 3 ) as an injection molded part with at least one on its inner and / or outer periphery ( 4 . 11 ) layer ( 5 . 5a . 5b ) is trained. Pressure vessel ( 1 ) according to claim 1, characterized in that the individual layer ( 5 . 5a . 5b ) is formed from at least one of the following components or a combination thereof: film, preferably metal foil ( 21 . 21a . 21b ), in particular aluminum foil or stainless steel foil - Plastic film, in particular plastic film with at least one layer of the same thermoplastic material as the back-injected plastic - fabric of metal fibers and / or glass fibers and / or carbon fibers - scrim of metal fibers and / or glass fibers and / or carbon fibers - grid and / or network structure a plastic and / or metal prepreg, in particular fiber fabric preimpregnated with thermoplastic, in particular glass fiber fabric. Pressure vessel ( 1 ) according to one of claims 1 or 2, characterized in that the individual layer ( 5 . 5a . 5b ) has a thickness in the range from 50 μm to 1000 μm, preferably 100 μm to 400 μm, particularly preferably 100 μm to 200 μm. Pressure vessel ( 1 ) according to one of claims 1 to 3, characterized in that this is designed as a composite component, wherein the plastic container ( 3 ) on its inner and / or outer periphery ( 4 . 11 ) with the at least one layer ( 5 . 5a . 5b ), in particular film ( 5 . 5a . 5b . 5.1 - 5.n ) cohesively with formation of a boundary layer ( 6 ) in the joining area ( 7 ) connected is. Pressure vessel ( 1 ) according to claim 4, characterized in that the boundary layer ( 6 ) comprises: - a thermoplastic and / or thermoplastic partially crosslinking and / or crosslinking adhesive system having a thickness in the range of 5 .mu.m to 100 .mu.m, preferably 10 .mu.m to 50 .mu.m, more preferably 10 .mu.m to 25 .mu.m. Pressure vessel ( 1 ) according to one of claims 1 to 5, characterized in that the plastic container ( 3 ) on its inner and / or outer periphery ( 4 . 11 ) with the at least one layer ( 5 . 5a . 5b ) is positively connected. Pressure vessel ( 1 ) according to one of claims 1 to 6, characterized in that the plastic container ( 3 ) consists of one of the following materials: a polymer or a combination of polymers, in particular polycarbonate + acrylonitrile-butadiene-styrene (PC / ABS), polyamides (PA), polyphthalamide (PPA), polycarbonate (PC), polyethylene (PE) , Polypropylene (PP), polyacetal (POM), polysulfone (PSU), polyethersulfone (PES or PESU), polyphenylene sulfide (PPS), polyethersulfone (PPSU), polyphenylene ether (PPE or PPO). Pressure vessel ( 1 ) according to one of claims 1 to 7, characterized in that the plastic container ( 3 ) consists of a transparent or semi-transparent plastic. Pressure vessel ( 1 ) according to one of claims 1 to 8, characterized in that the end regions ( 13.1 . 13.2 ) one or at least two layers ( 5 . 5a . 5b ) are arranged and formed such that they overlap and are positively connected and / or materially connected to each other. Method for producing a pressure vessel ( 1 ), comprising one, a cavity ( 2 ) forming and pressure-tight closable plastic container ( 3 ), characterized by the following features: - providing at least one layer ( 5 . 5a . 5b ), in particular a film; - provision of a shaping tool ( 14 ) for forming the plastic container ( 3 ); Behind or overmolding / casting of the at least one layer ( 5 . 5a . 5b ), in particular film under pressure in the forming tool ( 14 ) by casting, in particular injection molding. Method according to claim 10, characterized in that the at least one individual layer ( 5 . 5a . 5b ) is formed from at least one of the following components or a combination thereof: film, preferably metal foil ( 21 . 21a . 21b ), in particular aluminum foil or stainless steel foil - Plastic film, in particular plastic film with at least one layer of the same thermoplastic material as the back-injected plastic - fabric of metal fibers and / or glass fibers and / or carbon fibers - scrim of metal fibers and / or glass fibers and / or carbon fibers - grid and / or network structure a plastic and / or metal prepreg, in particular fiber fabric preimpregnated with thermoplastic, in particular glass fiber fabric. Method according to claim 10 or 11, characterized in that the at least one layer ( 5 . 5a . 5b ) at the intended joining surface ( 7 ) with a bonding agent ( 9 ) is coated. Method according to one of claims 10 to 12, characterized in that the shaping of the at least one layer ( 5 . 5a . 5b ), at least partially by the pressure applied by the injection molding during the injection molding process, in particular injection pressure occurs. Method according to one of claims 10 to 13, characterized in that one and / or more layers ( 5 . 5a . 5b ) are used and these are formed before and / or during the shaping process such that at least two layers ( 5 . 5a . 5b ) and / or two end regions ( 13.1 . 13.2 ) a situation ( 5 . 5a . 5b ). Method according to one of claims 10 to 14, characterized in that the at least one layer ( 5 . 5a . 5b ) Recesses ( 15 . 18 ), which during the casting form-fitting connections with the resulting plastic container ( 3 ) and / or different end regions ( 13.1 . 13.2 ) one or more layers ( 5 . 5a . 5b ) train. Method according to one of claims 10 to 15, characterized in that at least one layer ( 5 . 5a . 5b ) forming at least one plastic-free supernatant ( 26 ) and the supernatant ( 26 ) is designed and arranged such that it is suitable with a further component ( 27 ) to be connected. Method according to one of claims 10 to 16, characterized in that at least one layer ( 5 . 5a . 5b ) Recesses ( 18 ), which in the shaping tool ( 14 ), that in the recess in the forming tool a connection ( 20 ) to the plastic container ( 3 ) is formed during production of this.

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