Method for producing a nozzle

Abstract

Method for producing a nozzle for connecting a fluid line to a container (1) made of thermoplastic material, wherein the nozzle has a first nozzle-shaped, at least single-layer material arrangement (6) and a second nozzle-shaped, at least single-layer material arrangement (7), of which the first material arrangement (6) is thinner than the second material arrangement and both have thermally deformable material as at least a predominant component and form a fusion bond with one another, wherein in a first step the first material arrangement (6) is formed into a flat film or plate or into a tube by extrusion or injection molding, that in a second step the film or plate is formed into a first preform with a nozzle contour by deep drawing or the tube is formed by blow molding, that in a third step the second material arrangement (7) is formed on one side of the first preform by injection molding,Coinjection or monosandwich process with a nozzle contour is applied, and in the case of the first preform formed from the film or plate, its base is cut out before, during or after the third step, characterized in that at least one of the material arrangements acts as a diffusion barrier layer against hydrocarbons in the finished nozzle, the second material arrangement (7) has a core layer (7b) and a skin layer (7a) which are produced in the coinjection or monosandwich process, and that the skin layer (7a) and the first material arrangement (6) form a fusion bond.

Description

[0001] The invention relates to a method for producing a nozzle for connecting a fluid line to a container made of thermoplastic material, wherein the nozzle has a first nozzle-shaped, at least single-layer material arrangement and a second nozzle-shaped, at least single-layer material arrangement, of which the first material arrangement is thinner than the second material arrangement and both have thermally deformable material as at least a predominant component and form a fusion bond with one another, wherein in a first step the first material arrangement is formed into a flat film or plate or into a tube by extrusion or injection molding, that in a second step the film or plate is formed into a first preform with a nozzle contour by deep drawing or the tube is formed into a first preform by blow molding,that in a third step, the second material arrangement is applied to one side of the first preform using the injection molding, co-injection, or monosandwich process with a nozzle contour, and that in the case of the first preform formed from the film or sheet, its base is cut out before, during, or after the third step.

[0002] A similar process is known from DE 199 53 746 C2. There, the first material arrangement consists of two adjacent thin layers and the second material arrangement of an outer layer that is thicker than the two-layer first material arrangement and essentially determines the mechanical strength of the nozzle. The three layers are to be injection molded using the coinjection or monosandwich process. However, it is extremely difficult to make the single-layer first material arrangement significantly thicker than the second material arrangement, since two layers of a total three-layer wall of a nozzle then form a thin one- or two-part skin layer whose total wall thickness is generally less than that of the core layer. Thus, with coinjection, the skin layer usually has a maximum thickness of about 2 mm.If the wall thickness of the nozzle is to be about 10 mm for strength reasons and the thickest layer is to be on the outside, such a layer arrangement can practically not be produced using the co-injection or monosandwich process.

[0003] On the other hand, many materials cannot be injected in multiple layers in a single injection process, whether using coextrusion or directly one after the other while the previously injected layer is still molten. For example, an aluminum layer can't be injected first, followed immediately by a plastic layer while the aluminum layer is still molten, because aluminum has a much higher melting temperature than plastic, which the plastic wouldn't be able to withstand. The same applies to materials with different flow behavior.

[0004] The subsequently published WO 2005 / 044 538 A1 describes a plastic spout for beverages and bulk food products. The spout has a multilayer plastic-aluminum laminate on its inner side, which serves as an oxygen barrier. It is manufactured by deep-drawing the multilayer plastic-aluminum laminate onto the projection of an injection mold, and then injecting the plastic material of the spout onto the outer side of the plastic-aluminum laminate, creating a bond between the plastic material of the spout and the plastic-aluminum laminate.

[0005] DE 42 39 909 C1 describes a manufacturing method for a two-part connecting piece for a vehicle's fuel tank. It is proposed to form the two parts of the connecting piece from different plastic materials, each with a different creep tendency. Furthermore, it is proposed to first produce a first part of the connecting piece using an injection molding process, and then to mold the second part of the connecting piece onto the first part of the connecting piece using a subsequent injection molding process.

[0006] DE 199 53 746 A1 describes a method for producing a plastic nozzle consisting of several sub-regions. In a first sub-region, the plastic nozzle has several layers of different materials. It is proposed to produce the first sub-region using a multi-component injection molding process or a sandwich injection molding process.

[0007] EP 1 084 889 A1 describes a tank insert and a method for its production. It proposes producing a multilayer laminate comprising one or more barrier layers using a coextrusion process and subsequently forming it using a compression molding process. The insert is then welded to a fuel tank.

[0008] DE 102 41 286 A1 discloses a component for connecting a fluid line to an opening of a plastic container. The component is configured in a nozzle-shaped manner, wherein a second material arrangement is injected into a still-plastic core of the first material arrangement. A third material arrangement can also be injected into the still-plastic core of the second material arrangement. At least the third material arrangement can have increased diffusion barrier capacity and be formed, for example, from EVOH. Additionally, electrically conductive fibers can be provided in at least one of the material arrangements.

[0009] DE 101 44 892 A1 describes a multilayer plastic body comprising a first material arrangement and a second material arrangement. The plastic body can be formed by co-injection or by composite injection molding, with one of the two material arrangements forming a preform.

[0010] The invention is based on the object of specifying a method of the type mentioned at the outset in which the thickness and relative position of the layers can be largely freely selected for a given wall thickness of the nozzle, regardless of the function of the layers.

[0011] The object is achieved by a method having the features of claim 1 or 3 or 5. Advantageous embodiments can be found in the subclaims.

[0012] According to the invention, this object is achieved in that at least one of the material arrangements acts as a diffusion barrier layer against hydrocarbons in the finished nozzle, the second material arrangement has a core layer and a skin layer which are produced by the coinjection or monosandwich process, and that the skin layer and the first material arrangement form a fusion bond.

[0013] With this solution, the thicker material arrangement can form the radially outer or inner material arrangement of the nozzle, depending on whether the first preform for applying the second material arrangement is arranged on the correspondingly shaped inside of the outer wall of an injection molding tool or on the correspondingly shaped outside of a core in the injection molding tool. To achieve the desired thickness of the second material arrangement, the thickness of the gap between the first preform and the inside of the wall or the outside of the core of the molding tool is then selected accordingly. The thickness of the first preform is selected during deep drawing or blow molding according to the desired wall thickness of the nozzle.The material of the second material arrangement can be selected according to the desired strength and function of the second material arrangement, so that the second material arrangement, on the one hand, serves as a support for the first preform and, on the other hand, forms a solid fusion or welded connection with the material of the container, preferably a fuel tank of a motor vehicle, and the first preform. Conversely, the material of the first preform can be selected such that it forms a solid fusion or welded connection with the material of the second material arrangement.

[0014] The second material arrangement comprises a core layer and a skin layer, which are manufactured using a coinjection or monosandwich process, whereby the skin layer and the first material arrangement form a fusion bond (are compatible). If a predetermined thickness is selected for the second material arrangement in this embodiment, then the core layer—with a wall thickness of the nozzle of, for example, 10 mm and a thickness of only approximately 2 mm for the first material arrangement or the first preform—can have a thickness of 4 mm, and the skin layer or the two skin layers lying on either side of the core layer (if the skin layer is divided into two skin layers by the core layer) can each have a maximum thickness of 4 mm in total or 2 mm per skin layer on either side of the core layer.

[0015] The material of the skin layer(s) can be PE and that of the core layer can be a diffusion barrier layer against hydrocarbons, which comprises at least one of the materials PA, EVOH, PET, PBT, PBN, PEN, POM, fluorothermoplastic and PPS.

[0016] The diffusion barrier layer may comprise a reinforcing material, particularly glass fibers. The core layer may also comprise a reinforced material, e.g., PE or PP reinforced with glass fibers, glass beads, or mineral particles.

[0017] It is then possible for the (one-piece) skin layer to be applied to the outside or inside of the first preform and for the second material arrangement to be formed as a flange in a first end section to be connected to the container and with at least one retaining rib on the outside in a second end section, and for the core layer to be injected into the ribbed end section and up to or into the flange. The core layer, designed as a diffusion barrier layer, thus simultaneously forms a stiffening layer, at least in the area between the ribbed end section and the flange, since the fluid line pushed onto it is usually clamped around this area using a hose clamp, so that this intermediate area must withstand the clamping pressure of the hose point without deforming.

[0018] If the nozzle has a first nozzle-shaped, three-layer material arrangement which is produced at least predominantly from thermoplastic material in a coinjection or monosandwich process, according to a second solution to the problem, it is ensured according to the invention that the skin layer of the first material arrangement is fused with a second material arrangement which consists at least predominantly of thermoplastic material which forms a fusion bond with the skin layer of the first material arrangement, wherein at least one of the material arrangements acts as a diffusion barrier layer against hydrocarbons in the finished nozzle, wherein the first material arrangement is arranged as a preform in a mold,that a third material arrangement is produced in three layers using the co-injection or monosandwich process, at least predominantly from thermoplastic material, and is arranged in the mold as a second preform with a gap to the first preform, and that the second material arrangement is injected into the gap and forms a fusion bond with the skin layers of both preforms.

[0019] This eliminates the need for deep drawing or blow molding to form the first preform from the first material arrangement. Nevertheless, the first material arrangement can be formed as a preform thinner than the second material arrangement.

[0020] Furthermore, the second material arrangement can be single-layered, comprise predominantly PE or PA and have substantially the same thickness as the two preforms combined or be thicker in order to provide the nozzle with the required strength and rigidity.

[0021] In addition, in the second solution, the second material arrangement between the two preforms can be formed in three layers using the coinjection or monosandwich process and its skin layers can form a fusion bond with the skin layers of the two preforms.

[0022] The skin layers of the first material arrangement may comprise a PE and their core layer may comprise a diffusion barrier layer for hydrocarbons.

[0023] The skin layers of the second material arrangement may also comprise a PE, and their core layer may comprise a diffusion barrier layer for hydrocarbons or reinforcement material.

[0024] The diffusion barrier layer of the second material arrangement preferably comprises PA or EVOH, and the core layer of the second material arrangement preferably has substantially the same thickness as its two skin layers combined or is thicker.

[0025] From DE 199 53 746 C2 a method for producing a nozzle for connecting a fluid line to a container made of thermoplastic material is also known, wherein the nozzle has a first, a second and a third rotationally symmetrical material arrangement, each consisting predominantly of thermoplastic material, wherein the first material arrangement is at least single-layered and surrounds the second material arrangement, the third material arrangement surrounds the first material arrangement, the first, second and third material arrangements are connected by a fusion connection and form a flange of the nozzle on the side of the container and the first material arrangement and the second material arrangement extend to a surface of the flange to be connected to the container.

[0026] A fourth solution to the stated problem, based on the known method mentioned at the outset, consists in that in a first step one of the two material arrangements is formed into a preform with a nozzle contour in a first mold cavity, in that in a second step the other of the two material arrangements is molded onto the first preform in a second mold cavity and in that the plastic of one of the two material arrangements, which comes into contact with the fluid line during connection, has an electrically conductive additive.

[0027] With this solution, the first preform can be formed in the first step, and the entire nozzle in the second step. If the fluid line is electrically conductive to prevent electrostatic charging when filling the container—for example, a motor vehicle tank with a hydrocarbon such as gasoline or diesel—the entire connection, consisting of the fluid line and the nozzle directly connected to the container, would be protected against electrostatic charging.

[0028] It is ensured that both material arrangements comprise PE, that a first layer is injected into the PE of at least one of the two material arrangements using the co-injection or monosandwich process, which forms a fusion bond with PE and a plastic that is a diffusion barrier for hydrocarbons, and that a second layer is injected into the first layer using the co-injection or monosandwich process, which comprises the plastic that is a diffusion barrier for hydrocarbons. This ensures that the diffusion pressure or the vapor pressure that develops at higher temperatures of the hydrocarbon diffusing through the PE, such as fuel in the form of gasoline or diesel oil, cannot lift the PE from the diffusion-barrier layer, which would eventually cause it to peel off.Likewise, the different swelling behavior of the diffusion-barrier layer and the PE would not result in the PE separating from the diffusion-barrier layer. If the diffusion-barrier layer is injected only or also into the radially outer material arrangement of the nozzle, the formation of a fusion bond between the diffusion-barrier layer and the surrounding PE would prevent the risk of the PE being lifted and removed from the diffusion-barrier layer by mechanical forces.

[0029] In order to achieve the strongest possible fusion bond between the first layer and the polyethylene of the material arrangement in question as well as the diffusion-barrier layer, it is advantageous if the plastic which is diffusion-barrier to hydrocarbons is PA or EVOH and the first layer comprises a PE which has been adhesion-modified by means of maleic anhydride and, if the diffusion-barrier plastic is PA, whose amino end group concentration is equal to or greater than 40 milliequivalents per kilogram.

[0030] With this design, it is also advantageous if the first and second layers of one material arrangement extend over more than 50%, preferably more than 90%, of the length of this material arrangement. The diffusion barrier capability of the nozzle is then ensured over a very large portion of the nozzle's length.

[0031] If the first and second layers of the thicker material arrangement extend over less than 100%, but still over more than 50%, preferably more than 90%, of the length of the thicker material arrangement, a relatively large connection surface between the thicker material arrangement and the container is ensured even with this design of the nozzle, and thus a firm connection between the nozzle and the container is achieved.

[0032] In cases where the diffusion barrier capability of the nozzle is not very demanding, the first and second single-layer material arrangements can be made of plastics that form a fused bond not only with each other but also with the container. In this case, only one material arrangement needs to have the electrically conductive additive, preferably the radially inner material arrangement, which can be thinner than the radially outer material arrangement. If the container is made of PE or HDPE, both material arrangements can also predominantly consist of PE.

[0033] Since only one material arrangement contains the conductive additive, the entire nozzle can be manufactured more cost-effectively than with a single-layer design of the entire nozzle with a conductive additive, despite the conductive additive increasing material costs. The other material arrangement then has greater chemical resistance and stress cracking resistance due to the lack of a conductive additive. Since both material arrangements also form a fused bond with the container, the molten plastic of the conductive material arrangement cannot penetrate between the other material arrangement and the container and impair its connection with the container.

[0034] The invention and its further developments are described in more detail below with reference to the accompanying drawings of preferred embodiments. These drawings show: Fig. 1 a nozzle manufactured according to a first embodiment, Fig. 2 a nozzle manufactured according to a second embodiment, Fig. 3 a nozzle manufactured according to a third embodiment, Fig. 4 shows a nozzle produced according to a fourth embodiment of a method according to the invention, Fig. 5 a nozzle manufactured according to a fifth embodiment, Fig. 6 a nozzle manufactured according to a sixth embodiment, Fig. 7 a nozzle manufactured according to an embodiment, Fig. 8 shows a nozzle produced according to a further embodiment of a method according to the invention, Fig. 9 a nozzle produced according to a further embodiment of a method according to the invention, Fig. 10 shows a nozzle produced according to a further embodiment of a method according to the invention, Fig. 11 a nozzle manufactured according to a further embodiment, Fig. 12 a nozzle manufactured according to a further embodiment, Fig. 13 a nozzle manufactured according to a further embodiment, Fig. 14 a nozzle manufactured according to a further embodiment, Fig. 15 a nozzle manufactured according to a further embodiment, Fig. 16 a nozzle manufactured according to a further embodiment, Fig. 17 a nozzle manufactured according to a further embodiment, Fig. 18 a nozzle manufactured according to a further embodiment and Fig. 19 a nozzle produced according to a further embodiment of the method according to the invention.

[0035] The Fig. The nozzles shown in 1 to 6 and 12 to 14 are for illustrative purposes only.

[0036] The Fig. The nozzles shown in 1 to 12 are multi-layered and are used to connect a (only in Fig. 13, Fig. 15 and Fig. 18) fluid line, e.g. a hose made of diffusion-tight plastic, with a container 1 for hydrocarbons consisting predominantly of plastic, here a motor vehicle tank for gasoline or diesel oil, of which only one wall 2 with a filler opening 3 is shown. The fluid line can additionally have an electrically conductive additive to prevent electrostatic charging. Each nozzle also consists at least predominantly of thermoplastic plastic and is integrally connected to the edge of the filler opening 3, here welded, so that a fusion connection is created between the nozzle and the container 1. For each nozzle, the container-side end section is provided with a circumferential flange 4 and the end section facing away from the container 1 is provided with a circumferential retaining rib 5. In the area between flange 4 and retaining rib 5 according to the Fig. The nozzle is slightly thinner on models 1 to 12. When connecting the fluid line, it is pushed onto the nozzle over the retaining rib 5, except for the thinner section, and then clamped in place with a hose clamp.

[0037] While the container 1 is made of HDPE (high-density polyethylene) with an intermediate layer made of PA or EVOH (not shown) that is diffusion-barrier to hydrocarbons, the nozzle Fig. 1 has on the outside a single-layer first material arrangement 6 which consists predominantly of thermoplastic, in this case one of the diffusion-barrier materials PA, EVOH, PET, PBT, PBN, PEN, POM, fluorothermoplastic, PPS. On the inside, the nozzle has a second single-layer material arrangement 7 which also consists predominantly of thermoplastic, in this case PE, which is compatible with the plastic of the container 1 and the first material arrangement 6, i.e. can be welded, and forms a fusion bond. If necessary, the second material arrangement 7 can be modified accordingly to achieve the fusion bond. The thermoplastic of the first material arrangement 6 can additionally have electrically conductive particles, e.g. made of graphite or metal. The second material arrangement 7, on the other hand, is preferably reinforced, e.g. with glass or carbon fibers.

[0038] The nozzle after Fig. 1 is manufactured in such a way that in a first step the first material arrangement 6 is formed into a flat film or plate or into a tube by extrusion or injection molding, that in a second step the film or plate is formed into a first preform with a nozzle contour by deep drawing or the tube is formed by blow molding, that in a third step the second material arrangement 7 is applied to one side of the first preform by injection molding with a nozzle contour, and that in the case of the first preform formed from the film or plate, its base is cut out before, during or after the third step.

[0039] Both material arrangements 6 and 7 can be of different thicknesses, while maintaining the desired wall thickness of the nozzle, ie, for example, the first material arrangement 6 can be very thin, as is sufficient for a diffusion barrier layer, and the second material arrangement 7 can be chosen to be correspondingly thick, so that it can serve as a carrier for the first material arrangement 6 and to achieve the desired strength of the nozzle and its connection to the container 1.

[0040] A particular advantage of this process is that it can also be used to join material arrangements that cannot be joined in a single injection molding process (using the coextrusion process), such as an axially continuous metal layer with a plastic layer due to their very different melting temperatures. Metal has a much higher melting temperature than thermoplastics, so the plastic would decompose at the metal's higher melting temperature.

[0041] In the embodiment according to Fig. 2, the first material arrangement 6 consists of a first layer 6a and a second layer 6b, which are fused together, are layered one on top of the other using a coextrusion process or layer by layer using an injection molding process to form the film, sheet, or tube, and are then deep-drawn in the case of the flat film or sheet or blow-molded in the case of the tube to form the nozzle-shaped first preform. The first preform is then in turn bonded to the second material arrangement 7 in the same manner as in the embodiment according to Fig. 1. The thickness ratios can be selected similarly to the first embodiment. While the materials of the second material arrangement 7 are again selected as in the first embodiment, the materials of the layers 6a and 6b of the first material arrangement 6 are selected differently, with the outer layer 6a again being made as a diffusion barrier layer from the same materials as the first material arrangement 6 according to Fig. 1 and the middle layer 6b can be formed from an adhesion promoter. However, it is also possible to produce layer 6b as a diffusion barrier layer and the outer layer 6a, for example, from PE or PA, whereby the middle layer 6b must again be compatible (fusible) with layers 6a and 7.

[0042] Instead of forming the first material arrangement 6 from the layers 6a and 6b by deep drawing or blow molding to form the first preform, it is also possible to produce the first preform from the layers 6a and 6b in a multi-component injection molding process (one layer after the other) in one mold.

[0043] In the embodiment according to Fig. 3, the first material arrangement 6 consists of three layers 6a-6c, the materials of which are selected such that they form a fusion bond with the adjacent layer. Likewise, layer 6b forms a fusion bond with the second material arrangement 7. The layers 6a-6c are first layered one on top of the other using a coextrusion injection molding process or layer by layer using an injection molding process to form a flat film, sheet, or tube. From this layer arrangement, the first preform is then formed by deep drawing or blow molding, which is then placed in an injection mold and back-injected with the second material arrangement 7. The base is cut out of the deep-drawn, cup-like first preform before, during, or after the back-injection of the second material arrangement 7.

[0044] The layers 6a-6c are, in total, at most as thick as the second material arrangement 7, if the wall thickness of the nozzle is again only equal to that of the first exemplary embodiment. Of the three layers 6a-6c, at least two consist of different materials, one of which can be fused to the second material arrangement 7. For example, the radially outer layer 6c is electrically conductive due to an additive, the middle layer 6a is a barrier layer, and the radially inner layer 6b is an adhesion promoter that enables the connection between the middle layer 6a and the second material arrangement 7, which in turn comprises PE in order to be able to connect it to the container 1 by melting, but does not form a fusion bond with a barrier layer as the middle layer 6a, which comprises, for example, PA or EVOH, unless the PE of the second material arrangement 7 is adhesion-modified such that it forms a fusion bond with PA or PE.

[0045] Alternatively, the outer layer 6c can comprise adhesion-modified PE, the middle layer 6a can comprise PA or EVOH, and the second material arrangement 7 can also comprise adhesion-modified PE. The PE of the outer layer 6c would then, with the same overall wall thickness, have the same Fig. 2 compensate for the slightly smaller thickness of the second material arrangement 7 in order to achieve the same strength of the nozzle.

[0046] In the embodiment according to Fig. 4, the two material arrangements 6 and 7 are compared to those according to Fig. 1. That is, the first material arrangement 6 is arranged radially inward and the second material arrangement outside, while the production is carried out in the same way as in the first embodiment according to Fig. 1: First, the material arrangement 6 is produced as a first preform from a flat film or sheet by deep drawing or from a tube by blow molding. The second material arrangement 7 is then injection-molded around the outside of the first preform, with the bottom of the deep-drawn mold being cut out before, during, or after the second material arrangement 7 is injected around it. The materials of the two material arrangements 6 and 7 can again be the same as in the first embodiment.

[0047] Also in the embodiment according to Fig. In Figure 5, only the position of the two material arrangements 6 and 7 is reversed compared to the first and second embodiments. However, the manufacturing and materials are again the same as in the second embodiment.

[0048] In the embodiment according to Fig. 6 is also just the order of materials 6 and 7 compared to the Fig. 3 are exchanged, while the manufacturing process and the materials of the material arrangements 6 and 7 are opposite Fig. 3 remained the same.

[0049] In the embodiment according to Fig. 7, the order of materials 6 and 7 is also opposite to that according to Fig. 1 is reversed. However, the second material arrangement 7 consists of two layers, a skin layer 7a and a core layer 7b, which is injected into the still plastic core of the skin layer 7a using the coinjection or monosandwich process after the skin layer 7a has been injection-molded around the material arrangement 6 forming the first preform, which is produced in the same way as in the first embodiment. The core layer 7b can comprise a reinforcing material, e.g., glass or carbon fibers, or, if the inner material arrangement 6 forms a diffusion barrier layer made of, for example, PA or EVOH, it can form an additional barrier layer.

[0050] The core layer 7b extends from the end section with the retaining rib 5 of the nozzle over the thinner central region of the nozzle to the flange 4. When the core layer 7b is designed as a reinforcement layer, the central, somewhat thinner region can be made more resilient to the clamping pressure of the hose clamp. Alternatively, the core layer 7b can also be designed as an additional diffusion barrier layer if the first material arrangement 6 is also designed as a diffusion barrier layer, in order to increase the diffusion barrier capacity of the nozzle.

[0051] The embodiment according to Fig. 8 differs from that according to Fig. 7 only in that the core layer 7a is longer so that it extends into the flange 4 in order to further increase the strength or diffusion barrier capacity of the nozzle.

[0052] In the embodiment according to Fig. 9, the first material arrangement 6 has a first layer 6a and a second layer 6b, each of which is produced according to the same method as the first preform from the first material arrangement 6 in the embodiment according to Fig. 1 are formed in the first and second steps into a first preform and a second preform. The two preforms 6a and 6b are then arranged in a suitably shaped injection molding tool with a distance from one another corresponding to the desired thickness of the second material arrangement, and then a first layer 7a of the second material arrangement 7 is injection molded between the first preform and the second preform, i.e. between the layers 6a and 6b, and a third layer 7b of the second material arrangement 7 is injected into the still plastic core of the first layer 7a of the second material arrangement 7 using the co-injection or monosandwich process.

[0053] Here, the outer layer 6a can comprise thermoplastic material with electrically conductive particles, and the inner layer 6b can comprise diffusion-barrier PA or EVOH, while layer 7a can comprise modified PE, and the middle layer 7b can comprise reinforcing material, but all adjacent layers can be fused together. However, since layer 7b is enclosed in the material of layer 7a, it is not absolutely necessary for layer 7b to be fused (compatible) with layer 7a. Furthermore, layer 7b can be injected further axially, e.g., up to or into flange 4.

[0054] In the embodiment according to Fig. 10, of which only one half is shown because the other half is symmetrical to the other half, as in the previous embodiments, the nozzle is made of a first nozzle-shaped material arrangement 6, which has three layers 6a, 6b, and 6c, a second nozzle-shaped, but single-layer material arrangement 7, and a third nozzle-shaped material arrangement 8 with three layers 8a, 8b, and 8c. All arrangements consist at least predominantly of thermoplastic material.

[0055] The first material arrangement 6 is manufactured as a first preform using the coinjection or monosandwich process, so that its outer layers 6a and 6b form a skin layer and its inner layer 6c forms a core layer which is approximately as thick to approximately twice as thick as each of the layers 6a and 6b.

[0056] Layers 6a and 6b comprise PE, while layer 6c comprises PA or EVOH and forms a diffusion barrier layer for hydrocarbons. The second material arrangement 7 also comprises PE, so that it forms a fusion bond with layer 6b.

[0057] The third material arrangement 8 is also produced using the coinjection or monosandwich process as a second preform, so that its outer layers 8a and 8c form a skin layer and its inner layer 8b forms a core layer. The layers 8a, 8c also comprise PE, while the inner layer 8b comprises PA or EVOH, so that the latter forms a diffusion barrier layer for hydrocarbons. Thus, layer 8c also forms a fusion bond with the material arrangement 7, since they both comprise PE. While layers 8a and 8c are approximately the same thickness, layer 8b is approximately the same thickness to twice as thick as one of the layers 8a, 8c. As with layer 6c, this is possible because the maximum thickness of the material arrangements 6 and 8 is reduced by appropriately thinning the cavity of the mold in which the coinjection orMonosandwich process is used to produce the material arrangements 6 and 8, is chosen to be equal to 2 to 4 times the skin layers, the thickness of which is generally constant at 1 to 2 mm in a co-injection or monosandwich process.

[0058] Alternatively, the material arrangements 6 and 8 can also be coextruded or their layers can be successively injected layer by layer into a film, sheet, or tube using the extrusion injection molding process, and then the film or sheet can be formed into the first or second preform by deep drawing or the tube can be blow molded, respectively, after which the two preforms are then arranged with a gap between them in a correspondingly shaped injection mold, and the second material arrangement 7 is injected into the gap. In the case of deep-drawn preforms, their base can again be cut out before, during, or after the injection of the second material arrangement 7 in order to obtain the nozzle shape open at both ends. Furthermore, it is possible in the embodiment according to Fig. 10 to omit the first material arrangement 6 or the third material arrangement 8.

[0059] In the embodiment according to Fig. 11 not only the material arrangements 6 and 8 as in the embodiment according to Fig. 10 in the co-injection or monosandwich process, but also the second material arrangement 7 is injected into the space between these two preforms in a mold using the co-injection or monosandwich process after the completion of these two preforms, so that the outer layers 7a and 7c of the second material arrangement 7 also form a skin layer made of PE and the inner layer 7b forms a core layer made of PA as a diffusion barrier layer and carrier layer. In contrast, the first material arrangement 6 forms a skin layer comprising PA and a core layer 6c comprising EVOH on both sides of the core layer 6c, thus forming a further diffusion barrier layer. The third material arrangement 8 can then have skin layers 8a and 8c made of PE and a core layer 8b made of EVOH as an additional diffusion barrier layer.

[0060] Since the PA-containing core layer 7b of the second material arrangement 7 is not completely injected into the PE, as shown, up to the lower end of the PE forming the skin layer(s) 7a and 7c, which is to be welded to the container 1, a sufficiently large area of PE is present which can form a strong welded or fused connection with the PE of the container 1. Here, too, the thickness ratios of the layer can be selected such that the skin and core layers of the material arrangements 6 and 8 are approximately equally thin, while maintaining the required wall thickness of the nozzle, while the carrier layer 7b is relatively thick, approximately as thick as its skin layer(s) 7a, 7c (together) or thicker.

[0061] Likewise, in this case, the first material arrangement 6 or the third material arrangement 8 can be omitted.

[0062] Fig. 12 shows one half of a flange 4 of a nozzle produced according to a further embodiment of a method according to the invention in axial section. The part not shown, facing away from the container 1, is also provided with a retaining rib, as in the previous embodiments. The nozzle also has a first material arrangement 6, which lies radially outside or inside or, as shown, on both sides of a second material arrangement 7, and a third material arrangement 8, which, as in the previously described nozzles, consists predominantly of thermoplastic. The first material arrangement 6 is single-layered and has a relatively small thickness. It surrounds the significantly thicker second material arrangement 7. The third material arrangement 8 surrounds an end section 9 of the first and second material arrangements 6, 7, which end section 9 is therefore facing away from the surface 10 of the flange 4 to be connected to the container 1.The material arrangements 6, 7 and 8 can in turn form a fusion connection with each other.

[0063] The production of this nozzle is again carried out in such a way that in a first step the first material arrangement 6, ie the outer or inner or both, is formed into a flat film or plate or into a tube by extrusion or injection molding. In a second step the film or plate is formed into a preform by deep drawing or the tube by blow molding, which Fig. 12. However, at least the transitions of the material arrangement 6 or the preform formed from it do not have to transition at an angle into the end section 9. The transitions can also be round.

[0064] In a third step, the second material arrangement 7 is applied (back-injected) to one side of the preform formed from the outer or inner material arrangement 6 or from both using an injection molding process. In a fourth step, the third material arrangement 8 is injection-molded around the end section 9 of the first and second material arrangements 6, 7 in the region of the flange 4. In the process, a part 11 of the second material arrangement 7 not covered by the material arrangement 6 is also covered by the third material arrangement 8. In the case of the preform formed from the film or sheet, its base is cut out before, during, or after the third step.

[0065] The first material arrangement 6 has a diffusion barrier layer, the second material arrangement 7 has polyethylene (PE), and the third material arrangement 8 also has a diffusion barrier layer for hydrocarbons. The diffusion-barrier materials can also be the materials described in connection with the previous embodiments. They are preferably PA or EVOH.

[0066] The first material arrangement 6 and the third material arrangement 8 contain electrically conductive particles, e.g., particles of metal, graphite, or carbon. Since the first material arrangement 6 and the third material arrangement 8 are in contact with each other, a conductive layer is formed over the entire length of the nozzle to prevent electrostatic charging of the nozzle.

[0067] Instead of being single-layered, the first material arrangement 6 or its film or plate can also be produced in a multi-layered manner in the first step using the coextrusion process, wherein at least one of the layers is electrically conductive.

[0068] If the first material arrangement 6, as shown, covers both the radially outer and the radially inner sides of the second material arrangement 7, the largely non-diffusion-barrier PE of the second material arrangement 7 is covered by a double diffusion-barrier layer. In contrast, the thicker second material arrangement 7 can form a mechanically highly resilient, strong fusion bond by welding via the large annular surface 10 with the at least outer layer of the container 3, which also contains PE.

[0069] A further alternative may be that a further layer is injected into the second material arrangement 7 using the co-injection or monosandwich method before it has fully cured.

[0070] In the embodiment of the nozzle according to Fig. 13, of which only one half is shown, axially symmetrical with respect to the dash-dotted center line, the thinner material arrangement 6 is located inside and the thicker material arrangement 7 is located outside. Although the material arrangement 6 is approximately half as thick as the material arrangement 7, it can also be much thinner. It could also be somewhat thicker than shown, but should in any case be thinner than 70° of the thickness of the material arrangement 7.

[0071] The material arrangement 6 predominantly comprises one of the aforementioned plastics which is diffusion-barrier-resistant to hydrocarbons such as petrol or diesel oil, and contains an electrically conductive additive. The additive can be particles of graphite, metal or carbon, for example soot, or so-called electrically conductive nanotubes. Nanotubes have the advantage that they have a relatively large length-to-diameter ratio of approximately 100, so that overall they almost certainly form an electrically conductive connection across the entire length of the material arrangement 6. The amount of additive is selected such that the electrical resistance of the material arrangement 6 is in the range from 100 Ω to 10 7 Ω, preferably approximately 1000 Ω to 10 000 Ω, so that the material arrangement 6 does not become electrostatically charged when the container 1 is filled.

[0072] The material arrangement 7 contains predominantly PE, which, in contrast to the diffusion-barrier plastics, forms a melt bond with the HDPE of the container 1.

[0073] At least one of the two material arrangements 6 and 7 is adhesion-modified so that they also form a melt bond with each other. If the diffusion-barrier plastic of the material arrangement 6 is adhesion-modified such that it forms a melt bond with the PE of the material arrangement 7, it can also form a melt bond with the HDPE of the container 1.

[0074] When manufacturing the nozzle according to Fig. 13, in a first step, the thicker material arrangement 7 is formed in a first mold cavity into a preform with the nozzle contour shown, i.e. with a longer cylindrical section and the flange 4. In a second step, the thinner material arrangement 6 is then formed in a second mold cavity into the nozzle contour shown and at the same time is formed onto the first preform from the material arrangement 7, in such a way that the thinner material arrangement 6 melts the thicker material arrangement 7 on its entire inside beyond the end of the material arrangement 7 facing away from the surface 10 to be connected to the container 1 and is formed into the holding rib 5 projecting beyond the outside of the material arrangement 7.

[0075] After the nozzle has been fused to the outside of the wall 2 of the container 1 in the area of surface 10, for example by friction or mirror welding, the fluid line 12 in the form of a hose can be pushed onto the nozzle beyond the retaining rib 5 and, if necessary, clamped with a hose clamp 13. If the fluid line 12 also contains an electrically conductive additive, the entire connection from a filler neck attached to the end of the fluid line 12 (not shown) via the fluid line 12 and the material arrangement 6 to the container 1 is electrically conductive, so that it cannot become electrostatically charged when the container 1 is filled.If the container 1 additionally has an electrically conductive layer that covers its opening 3 and its outer side from the opening to the inner edge of the surface 10, the conductive connection also extends into the container 1. This conductive layer would indeed hinder or prevent a fusion connection of the material arrangement 6 with the container 1. However, due to its electrically conductive additive, the material arrangement 6 would hardly connect to the container 1 even without the conductive layer. However, since the material arrangement 7 is relatively thick compared to the material arrangement 6, the large-area connection between the material arrangement 7 and the container 1 can essentially determine the strength of the connection between the nozzle and the container 1. For the same reason, the material arrangement 7, as the carrier of the thin material arrangement 6, is alone able to ensure sufficient mechanical strength of the nozzle.The electrical connection between the fluid line 12 and the holding rib 5 of the material arrangement 6 also makes it possible to keep the material arrangement 7 free from an electrically conductive additive that at least impairs the fusion connection between the material arrangement 7 and the container 1.

[0076] In principle, however, it would also be possible to make the material arrangement 7 thinner than the material arrangement 6 and essentially from a diffusion-barrier plastic with an electrically conductive additive, while making the material arrangement 6 much thicker than the material arrangement 7 and essentially from a plastic that can be melted into the plastic of the container 1, without changing the overall contour of the nozzle. The electrically conductive connection would then run via the material arrangement 7 to the container 1. In this modification, merely a conductive layer of the container 1 from its opening 3 under the container-side edge of the material arrangement 6 through to or below the container-side edge of the material arrangement 7 would not be advisable, because the material arrangement 6 would then bond poorly to the container 1.The order of production of the preforms from the material arrangements 6 and 7 would then simply be reversed: In the first step, the preform would be formed from the material arrangement 6 and in the second step the preform would be formed from the material arrangement 7 and at the same time melted onto the material arrangement 6, ie formed while still in the molten state.

[0077] The design example of the nozzle according to Fig. 14 - the container 1 and the fluid line 12 are omitted in this illustration - differs from that according to Fig. 13 only in that the thinner material arrangement 6, except for an inner first layer 6c, is formed from the same material as the thicker material arrangement 7, and the layer 6c made of one of the aforementioned diffusion-barrier plastics, preferably PA or EVOH, is injected from the pointed end of the material arrangement 6 into the area of the material arrangement 6 that is still molten by injection molding using a coinjection or monosandwich process. Layers 6a and 6b form a skin layer, and layer 6c forms a thinner core layer of the second preform that extends over the entire length of the nozzle. The skin layer is in turn provided with an electrically conductive additive, while the inner layer 6c can also be provided with a conductive additive and is adhesion-modified so that it forms a fusion bond with the PE of the skin layer 6a, 6b.

[0078] The embodiment of the nozzle according to Fig. 15 differs from that according to Fig. 13 only in that a first layer 7b made of one of the aforementioned diffusion-barrier plastics, preferably PA or EVOH, is injected into the material arrangement 7 during the first step using a coinjection or monosandwich process. The layer 7b extends from the end of the material arrangement 7 facing away from the end to be welded to the container 1 and forming the sprue, over more than 50%, preferably more than 90% and less than 100% of the length of the nozzle, into the flange 4, i.e. not to the end to be welded, so that the PE of the material arrangement 7 can continue to form a solid fusion bond with the surface 10 on the container 1 during welding. With this design, the layer 7b itself does not need to form a fusion bond with the PE of the (skin) layers 7a, 7c of the material arrangement 7 because it is completely enveloped by the layers 7a, 7c of the material arrangement 7.Since the material arrangement 6 already comprises a diffusion-barrier-capable plastic, the layer 7b may alternatively comprise another thermoplastic that is not diffusion-barrier-capable but increases the mechanical strength of the material arrangement 7. In particular, it may contain a reinforcing material, e.g., glass fibers or carbon fibers.

[0079] In the embodiment of the nozzle according to Fig. 16, the material arrangement 6 is made of the same layers 6a to 6c, in the same step and from the same materials as the material arrangement 6 according to Fig. 14, while the material arrangement 7 in the embodiment according to Fig. 16 is designed in the same way as the material arrangement 7 of the embodiment according to Fig. 15.

[0080] Alternatively, the material arrangements 6 and 7 in the embodiments according to the Fig. 14 to 16 have at least one further layer injected using the co-injection or monosandwich method.

[0081] The design example of the nozzle according to Fig. 17 differs from that according to Fig. 13 essentially consists in the fact that both material arrangements 6 and 7 initially comprise PE during the manufacture of the nozzle - apart from the conductive additive, in this case carbon black, in material arrangement 6 - and during the injection molding of material arrangement 6 into its still molten core (the "soul"), while the skin consisting of layers 6a and 6b has already largely cured, a first layer 6d, 6e is injected from the injection point located at the pointed end of the nozzle using a coinjection or monosandwich process. The first layer 6d, 6e comprises PE grafted with maleic anhydride. As a result, the layer 6d, 6e is adhesion-modified compared to a PA or EVOH capable of forming a diffusion barrier for hydrocarbons such as gasoline or diesel oil.

[0082] After the skin layers 6d and 6e have largely cured, but their core is still molten, a second layer 6c is injected into the core of the first layer 6d, 6e using a coinjection or monosandwich process. This layer 6c comprises PA or EVOH. If PA is injected as layer 6c, its amino end group concentration is selected to be equal to or greater than 40 milliequivalents per kilogram. As a result, layer 6d, 6e forms a strong, integral fusion bond not only with the PE of material arrangement 6, but also with layer 6c. Since container 1 is made of PE or HDPE and material arrangement 7 is also made of PE, both continue to form a strong, integral fusion bond when the nozzle is welded to container 1. Since material arrangement 6 has a conductive additive in layers 6a and 6b, it does not form a very strong fusion bond with container 1.In particular, it does not form a fusion connection with the container 1 if it has a conductive coating which covers the opening 3 of the container 1 and its outer side from the opening 3 to the radially outer edge of the end of the material arrangement 6 facing the container 1, a continuous conductive connection of the type shown in . Fig. 17, a fluid line 12 (not shown) is formed via layers 6a, 6b into the container 1. Even if the amino end group concentration of the PA layer 6c is selected to be equal to or greater than 40 milliequivalents per kilogram, it will not form a fusion bond with the (HD)PE of the container. However, the bond between the PA of layer 6c and the PE layers 6a and 6b is stronger if the adhesion-modified layers 6d and 6e are provided. Overall, however, the thicker material arrangement 7 results in a very strong connection between the nozzle and the container 1.

[0083] Although the diffusion-barrier layer 6c is enclosed in the material arrangement 6 by layers 6a and 6b, it is nevertheless advantageous to fuse it with these layers 6a and 6b and thereby bond them. This is because it would be possible for gasoline or diesel oil to diffuse through layer 6b between it and layer 6c and, due to the diffusion and / or vapor pressure of the diffusing fuel—the latter especially at higher temperatures—and due to the different swelling behavior of PE and PA (PE swells more than PA), to separate layer 6b from layer 6c.

[0084] Although it would be possible to modify layers 6a and 6b with maleic anhydride, thus eliminating the first layer 6d, 6e, PE not adhesion-modified with maleic anhydride, such as that of layers 6a and 6b, has the advantage that it can be more easily made conductive by adding an electrically conductive additive, such as carbon black, than PE adhesion-modified with maleic anhydride.

[0085] The embodiment of the nozzle according to Fig. 18 differs from that according to the Fig. 15 and Fig. 17 in that the first layer 7d, 7e and the diffusion-barrier-capable second layer 7b injected into it are injected into the material arrangement 7. The first layer 7d, 7e therefore has the same material as the first layer 6d, 6e according to Fig. 17 and the diffusion-barrier layer 7b is the same material as the second layer 6c according to Fig. 17. In this case, the radially outer skin layer 7a of the material arrangement 7 is additionally protected by the adhesion-modified layer 7d, 7e against lifting or detaching from the diffusion-barrier layer 7b due to external mechanical forces, for example frictional forces acting on the layer 7a.

[0086] The design example of the nozzle according to Fig. 19 shows a combination of the layers of the material arrangement 6 according to Fig. 17 with the layers of the material arrangement 7 according to Fig. 18. It combines the advantages of both embodiments according to the Fig. 17 and Fig. 18 and increases the diffusion barrier capacity by using two diffusion barrier layers, i.e. the two layers 6c and 7b.

[0087] In cases where the diffusion barrier capability of the nozzle is not very demanding, both material arrangements can be made of plastics that form a material-to-material fusion bond not only with each other but also with the container 1. In this case, only one material arrangement, preferably the radially inner material arrangement, which is thinner than the radially outer material arrangement 7, needs to have the electrically conductive additive. If the container 1 comprises PE or HDPE, both material arrangements 6 and 7 can also comprise PE.

[0088] Since only one material arrangement 6 has the conductive additive, the entire nozzle can be manufactured more cost-effectively than with a single-layer design of the entire nozzle with a conductive additive, despite the conductive additive increasing material costs. Material arrangement 7 then has greater chemical resistance and stress cracking resistance due to the lack of a conductive additive. Since both material arrangements 6 and 7 also form a material-to-material fusion bond with the container, the molten plastic of the conductive material arrangement 6 cannot penetrate between the material arrangement 7 and the container 1 and impair its connection with the container 1.

Claims

[1] A method for producing a nozzle for connecting a fluid line to a container (1) made of thermoplastic material, wherein the nozzle has a first nozzle-shaped, at least single-layer material arrangement (6) and a second nozzle-shaped, at least single-layer material arrangement (7), of which the first material arrangement (6) is thinner than the second material arrangement and both have thermally deformable material as at least a predominant component and form a fusion bond with one another, wherein in a first step the first material arrangement (6) is formed into a flat film or plate or into a tube by extrusion or injection molding, that in a second step the film or plate is formed into a first preform with a nozzle contour by deep drawing or the tube is formed into a first preform by blow molding,that in a third step, the second material arrangement (7) is applied to one side of the first preform using the injection molding, co-injection or monosandwich process with a nozzle contour, and that in the case of the first preform formed from the film or plate, its base is cut out before, during or after the third step, characterized by that at least one of the material arrangements acts as a diffusion barrier layer against hydrocarbons in the finished nozzle, the second material arrangement (7) has a core layer (7b) and a skin layer (7a) which are produced by the coinjection or monosandwich process, and that the skin layer (7a) and the first material arrangement (6) form a fusion bond. [2] Method according to claim 1, characterized bythat the one-piece skin layer (7a) is applied to the outside or inside of the first preform and the second material arrangement (7) is formed in a first end section to be connected to the container (1) as a flange (4) and in a second end section externally with at least one holding rib (5) and that the core layer (7b) is injected into the ribbed end section and up to or into the flange (4), [3] Method for producing a nozzle for connecting a fluid line to a container (1) made of thermoplastic material, wherein the nozzle has a first nozzle-shaped, three-layer material arrangement (6) which is produced at least predominantly from thermoplastic material in the co-injection or monosandwich process, wherein the skin layer (6a, 6b) of the first material arrangement (6) is fused to a second material arrangement (7) which consists at least predominantly of thermoplastic material and which forms a fusion bond with the skin layer (6a, 6b) of the first material arrangement (6), wherein at least one of the material arrangements acts as a diffusion barrier layer against hydrocarbons in the finished nozzle, characterized bythat the first material arrangement (6) is arranged as a preform in a mold, that a third material arrangement (8) is produced in three layers in the co-injection or monosandwich process at least predominantly from thermoplastic material and is arranged in the mold as a second preform with a gap to the first preform and that the second material arrangement (7) is injected into the gap and forms a fusion bond with the skin layers of both preforms. [4] Method according to claim 3, characterized by that the second material arrangement (7) is formed in three layers using the coinjection or monosandwich process and its skin layers (7a, 7c) form a fusion bond with the skin layers (6b, 8c) of the two preforms. [5] Method for producing a nozzle for connecting a fluid line (12) to a container (1) comprising thermoplastic material, wherein the nozzle has a first nozzle-shaped, at least single-layer material arrangement (6) and a second nozzle-shaped, at least single-layer material arrangement (7), of which the first material arrangement (6) is thinner than the second material arrangement and both have thermoplastic material as at least a predominant component and form a material-to-material melt connection with one another, wherein in a first step, one of the two material arrangements (6, 7) is formed in a first mold cavity into a preform with a nozzle contour, that in a second step, the other of the two material arrangements (6, 7) is molded onto the first preform in a second mold cavity, and that the plastic of one of the two material arrangements (6, 7),which comes into contact with the fluid line (12) during connection, has an electrically conductive additive, , characterized by that both material arrangements (6, 7) comprise PE, that a first layer (6d, 6e; 7d, 7e) is injected into the PE of at least one of the two material arrangements (6, 7) using the co-injection or monosandwich method, which first layer forms a fusion bond with PE and a plastic which is a diffusion barrier for hydrocarbons, and that a second layer (6c; 7b) is injected into the first layer using the co-injection or monosandwich method, which second layer comprises the plastic which is a diffusion barrier for hydrocarbons.

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