INJECTION-MOLDED PLASTIC CONTAINER AND METHOD FOR MANUFACTURING THE SAME

Description

[0001] The invention relates to a container made of injection-molded plastic, essentially consisting of a container wall defining an interior of the container, according to the preamble of claim 1. The invention also relates to a method for producing such a container according to the preamble of claim 8 or according to the preamble of claim 12.

[0002] A container of this type can have a wide variety of shapes; typically, the container is formed from a container wall that is bowl- or tub-shaped and defines an upwardly open interior space that can be closed with a lid. The container wall then consists of a base and a side wall, which, depending on the basic shape of the base, can be rounded, bulged, n-shaped, and the like. However, other container shapes, such as a bottle, are also within the scope of the present invention.

[0003] A container of this type, which is known in the form of a household storage container from JP-A-2000-247366, consists of two plastic components, a first plastic component forming a skeleton with a base surface and several partial surfaces molded onto it, as well as a surrounding upper edge, while a second plastic component completes the skeleton to form the container wall and forms transparent windows. The contents of the container can be viewed from the outside through these transparent windows. Because they are arranged within a side surface of a container that is basically cuboidal in shape, the transparent windows are simultaneously protected from scratching and other damage that could impair the view through.

[0004] A container of this type is manufactured using a process in which the skeleton, including the base surface and molded-on partial surfaces, is first formed from the first plastic component. For this purpose, the first plastic component is plasticized by heating, i.e., brought into a flowable state. This melt is injected under pressure via an injection unit into a cavity of a divisible injection mold forming the shape of the skeleton, where it solidifies by cooling. The cavity is then expanded to form the overall shape of the container wall, or the divisible injection mold is opened, the solidified skeleton is removed, and placed into a cavity of a second divisible injection mold, which then defines the completed overall shape of the container wall.

[0005] A second plastic component is also plasticized by heating, injected under pressure into the enlarged cavity or into the cavity of the second injection mold, and solidified therein by cooling to complete the skeleton of the container wall.

[0006] By directly injecting the second plastic component onto the first plastic component, which has already solidified or is in the process of solidifying, a material-tight connection is created between the two plastic components, so that the finished container appears to be "cast from a single piece" and has corresponding properties.

[0007] An example of a corresponding method for producing a plastic article from two different plastic components according to the first alternative mentioned, i.e. in a single injection mould (two-component injection moulding technique), is described in EP-A-1 571 099.

[0008] Containers of this type, especially if they are bowl- or tub-shaped, generally need to be reinforced with bevels and stabilizing ribs to ensure sufficient dimensional stability. This is because the amount of plastic used to manufacture the container is a relevant factor in manufacturing costs. Sustainability is also a constant goal, aiming to use as little material as possible; energy consumption and thus the carbon footprint as well as the consumption of resources are naturally directly proportional to the amount of plastic used. The container wall should therefore be as thin-walled as possible.

[0009] The wall thickness of the container also directly influences the time required for the plastic material to solidify and cool, which in turn has a decisive influence on the manufacturing costs via the cycle times during container production. Furthermore, using as little plastic material as possible to manufacture a container of this type is also important in terms of the container's weight, which is reflected in the transport costs for distribution. Typical wall thicknesses for a container of this type are therefore 1.5 mm to 1.6 mm.

[0010] In order to be able to dispense with stabilizing ribs and bends for design reasons or due to handling characteristics, the wall thickness of the container must be at least partially increased to obtain a sufficiently inherently stable and high-quality container. However, this results in the disadvantages listed above. Even if only the skeleton of a container of this type is provided with a greater wall thickness and the skeleton is designed as a load-bearing structure, the disadvantage of the long solidification and cooling times in the manufacturing process remains.

[0011] In the field of manufacturing bottle crates injection-molded from a single plastic component, WO 2011 / 015214 A1 discloses adding a blowing agent to plastic granules prior to the injection molding process. This blowing agent, when injected into the cavity of the injection mold, causes the plastic to foam in those areas of the cavity that have a volume required for foaming. In other, narrower areas of the cavity, foaming largely fails to occur despite the blowing agent contained in the plastic.

[0012] The present invention is based on the object of proposing a container of the type mentioned at the outset, which consists of two plastic components, as well as a method for producing such a container using two-component injection molding technology or in two separate injection molds, in which or with which the described conflict of objectives no longer occurs.

[0013] This object is achieved by a container having the features of claim 1 and by a method having the features of claim 8 or a method having the features of claim 12. Advantageous embodiments of the container according to the invention are found in claims 2 to 7; preferred developments of the method according to the invention are set out in claims 9 to 11 and 13 and 14.

[0014] A container according to the invention made of injection-molded plastic, comprising a first plastic component from which a skeleton with a base surface and several struts or partial surfaces molded onto it is formed, as well as at least one second plastic component that completes the skeleton to form the container wall, is therefore characterized in that the skeleton is made of foamed plastic. This skeleton preferably has a material thickness of at least 2 mm, preferably from 2.5 mm to 4 mm, and particularly preferably of approximately 3 mm, i.e., from 2.8 mm to 3.2 mm.

[0015] Foaming the plastic creates a container wall or skeleton that is still made of injection-molded plastic and exhibits its typical material properties. However, a large number of gas bubbles enclosed in the plastic material significantly reduces the material required per unit volume, as well as the weight standardized per unit volume, allowing the wall thickness to be significantly increased compared to the previously typical 1.6 mm without adversely affecting the required material consumption, weight, or cycle time during production required for solidification and cooling of the material.

[0016] The inherent stability of the skeleton is significantly increased by a greater wall thickness, even when the skeleton is made of foamed plastic. This resolves the conflict of objectives mentioned above, resulting in a sufficiently inherently stable, high-quality container that largely eliminates the need for stabilizing ribs and bends. This also increases the design freedom in the arrangement of the second plastic component, which can, for example, extend over any corners and edges of the container and, in particular, into the base of the container. In this case, the base area of ​​the skeleton would not correspond to the total area of ​​the base of the container, but would be smaller.

[0017] To achieve the highest possible inherent stability of the container according to the invention, it is advantageous if the skeleton comprises a circumferential upper edge of the container (provided the container has a corresponding shape with a circumferential upper edge). For a typical container shape in the basic form of a cuboid, for example, a skeleton with a base surface and a circumferential upper edge, as well as relatively narrow struts between the base surface and the circumferential upper edge, would be sufficient to ensure very good inherent stability of the container.

[0018] Particular advantages arise from the inventive design of the container when the second plastic component is a transparent plastic, i.e., forms transparent windows in the finished container, as is known per se from the prior art described above. Because a second plastic component is used for this purpose, it can be made of non-foamed plastic, which is naturally extremely advantageous for transparent components of the container wall. The gas bubbles trapped in a foamed plastic would impair the transparent properties and render the transparent component more translucent.

[0019] The second plastic component preferably has a material thickness of at most 1.8 mm, preferably at most 1.5 mm, particularly preferably approximately 1 mm, i.e. from 0.8 mm to 1.2 mm. As explained above, a design with the thinnest possible walls reduces manufacturing costs and the consumption of resources and, if the second plastic component is a transparent plastic, also has the advantage of creating particularly transparent windows. With a suitable, inherently stable design of the skeleton, the second plastic component hardly has to contribute to the inherent stability of the container, so that a particularly low wall thickness is possible for the second plastic component.

[0020] The container according to the invention is particularly preferably manufactured using a two-component injection molding technique, which results in a particularly good material bond between the two plastic components, particularly when, as is preferred within the scope of the present invention, the two plastic components do not meet butt-jointly within the container wall, but rather, viewed perpendicular to the container wall plane, at least partially significantly overlap in a transition region from the first to the second plastic component. It is preferred here if a plurality of separate overlap regions are provided, which are expediently distributed over a circumference of the second plastic component, for example in a quilted seam-like or toothed form.These overlapping areas result in an advantageously large area in which the two plastic components adhere to one another, whereby an essentially periodic interruption of the overlapping areas prevents the first plastic component from becoming unstable in the transition area before the second plastic component is injected due to the lower material thickness in the overlapping areas.

[0021] The method according to the invention for producing a container from injection-molded plastic, which is essentially formed from a container wall that defines an interior of the container, is carried out in a first alternative using two-component injection molding technology. For this purpose, a skeleton with a base surface and several struts or partial surfaces molded onto it is first formed from a first plastic component. The first plastic component is plasticized by heating in a known injection molding machine, injected under pressure via a first injection unit into a cavity of a divisible injection mold, and solidified therein by cooling. The cavity corresponds to the shape of the skeleton, and the injection mold consists, as known per se, of a core half and a die half.Preferably, while the first plastic component is still solidifying, the cavity of the injection mold is expanded so that it changes from the shape of the skeleton to the shape of the entire container wall. A second plastic component is also plasticized by heating, injected under pressure via a second injection unit into the expanded cavity, and solidified therein by cooling, thus completing the skeleton with the second plastic component to form the container wall.

[0022] According to the invention, the first plastic component is mixed with a gas before being injected into the cavity. Since the plasticized mass expands as it flows into the cavity, the gas mixed with the first plastic component forms a multitude of bubbles, so that the first plastic component foams up as it flows into the cavity.

[0023] The expansion of the cavity from the shape of the skeleton to the shape of the container wall is preferably achieved using slides, which are known per se for the application of two-component injection molding technology. These slides are preferably arranged on the core half of the injection mold. This allows the first and / or second injection unit to be arranged in the die half, thereby achieving short distances from the injection nozzle to the cavity.

[0024] As an alternative to conventional slides, movable shut-off elements can also be used within the scope of the present invention to shut off parts of the cavity between the core half and the die half of the injection mold for the first shot containing the first plastic component, so that they are not part of the cavity into which the plastic material flows during the first shot. These shut-off elements thus ensure that the cavity, due to the "shut-down" parts of the cavity for the first plastic component, corresponds to the shape of the skeleton to be produced, while retracting the shut-off elements from the cavity expands the cavity to the shape of the entire container wall. Such shut-off elements can, for example, have the shape of a frame.

[0025] Particularly due to the preferred, different wall thicknesses of the first and second plastic components, the second plastic component is preferably injected through at least one hot runner. This ensures that the plasticized second plastic component is guided through the sprue system without significant cooling and is thus injected into the expanded cavity at the desired temperature, even when longer distances have to be covered to different injection points.

[0026] Preferably, the at least one hot runner has a valve with a needle valve. Such a needle valve prevents the injection point of the injection-molded container from being clearly visible on the finished product. This is particularly advantageous if the second injection unit, as preferred, is located in the cavity half of the injection mold, meaning the injection point is on the outside of the container.

[0027] Since, according to the invention, the first plastic component is mixed with a gas prior to injection, which is intended to cause foaming as the plastic component flows into the cavity, particular advantages arise if, in particular, the first injection unit for the first plastic component is provided with a needle valve. According to the invention, it has been recognized that otherwise there is a risk that the gas will escape prematurely into the cavity through a conventional injection nozzle, which would impair the foaming effect. Here, too, it can be advantageous to use a hot runner to inject the first plastic component.

[0028] In order to increase the connecting surface between the first and second plastic components and thereby make the material connection more durable and resistant, it is advantageous if the two plastic components in the finished container, in a plan view of a plane of the container wall, at least partially overlap. In the example of a transparent window, for example, the transparent second plastic component would have a larger surface area than the window left free by the skeleton for the second plastic component in order to achieve the aforementioned overlap. Accordingly, a preferred development of the method according to the invention consists in the cavity being gradually expanded by multi-part slides and / or by movable shut-off elements and / or by movable pins, which each create separate overlap areas between the two plastic components.

[0029] A second alternative of a method designed according to the invention for producing a container, which is essentially formed from a container wall that defines an interior of the container, dispenses with the two-component injection molding technique, but uses two different injection molds. Here, a skeleton with a base surface and several struts or partial surfaces molded onto it is molded from a first plastic component by plasticizing the first plastic component through heating, injecting it under pressure into a cavity of a first divisible injection mold that forms the shape of the skeleton, and solidifying it therein through cooling. The skeleton is then demolded by opening the injection mold and transferred into a second divisible injection mold, the cavity of which has the shape of the container wall.After closing this second injection mold, a second plastic component, which has also been plasticized by heating, is injected under pressure into the cavity of the second injection mold and solidified by cooling to complete the skeleton of the container wall.

[0030] Also according to this second alternative, the first plastic component is mixed with a gas before injection, which expands during the injection process in the cavity, i.e. after leaving the first injection unit, as it flows into the cavity and causes the first plastic component to foam.

[0031] While the two plastic components are usually made of thermoplastics such as polypropylene, polyethylene and polyamide, carbon dioxide (CO 2 ) is preferably used as the gas for foaming the first plastic component.

[0032] An exemplary embodiment of a container designed according to the invention or of a method designed according to the invention is described and explained in more detail below with reference to the accompanying drawings. They show: Figure 1 shows an embodiment of a container designed according to the invention in an isometric view; Figure 2 shows an isometric view of the injection mold or an injection molding tool for producing the container from Figure 1 ; Figure 3 a section through the injection molding tool Figure 2 ; Figure 4 a schematic isometric representation of a detail of the injection molding tool from Figure 3 ; Figure 5, detail X from Figure 3 , during injection of the first plastic component; Figure 6, detail X from Figure 3 , during injection of the second plastic component; Figure 7, detail X from Figure 3, after the injection of the second plastic component; Figure 8 a schematic isometric representation of a detail of the injection molding tool according to a second embodiment, in a starting position; Figure 9 the detail from Figure 8 before injecting the first plastic component; Figure 10 the detail from Figure 8 during injection of the first plastic component; Figure 11 the detail from Figure 8 before injecting the second plastic component; Figure 12 the detail from Figure 8 when injecting the second plastic component; Figure 13 the injection mold from the Figures 8 to 12 during ejection of the produced container; Figure 14 shows a section of a container produced with the second embodiment of the injection mold.

[0033] Figure 1shows an isometric view of a container designed according to the invention. This consists of a container wall 1, which has been manufactured using a two-component injection molding technique. This container wall 1 forms a trough-shaped container with a cuboidal basic shape, which, with a base surface 2 and four side walls 3, as well as a circumferential upper edge 4, encloses an interior space 8 that is open at the top. A skeleton 5, which according to the invention is made of foamed plastic, was formed from a first plastic component. This skeleton comprises the base surface 2, a strut 6 in each corner of the container, and the circumferential upper edge 4. In the side walls 3, the skeleton 5 continues in partial surfaces 7. These form a frame for the second plastic component 9, which is transparent and forms transparent windows 10 within the partial surfaces 7 of the skeleton 5.

[0034] According to the present invention, the skeleton 5 consists of a foamed plastic; in this embodiment, it is polypropylene that has been foamed with carbon dioxide.

[0035] Towards the interior 8, it can be seen that the second plastic component 9 and the partial surfaces 7 of the skeleton 5, viewed from a direction perpendicular to the container wall plane, overlap in a transition area surrounding the window 10. The second component 9 is therefore particularly well and permanently firmly bonded to the skeleton 5.

[0036] The production of the Figure 1 The container shown is produced in an injection moulding tool that is Figure 2shown in an isometric view. This consists of the actual injection mold 11 with a core half 12 and a die half 13, which can be separated from each other at a parting line 14 to remove an injection-molded part formed therein. This is indicated by dotted lines.

[0037] On the top side of the injection mold 11, a first injection unit 15 can be seen, through which the first plastic component is injected into a cavity 16. A second injection unit 17 is attached to the four side surfaces of the injection mold 11. Four injection nozzles 18, one for each window 10, are shown here, two of which are visible.

[0038] The "inner workings" of the Figure 2 The part of the injection mold shown is in Figure 3 , a cross-section through the Figure 2, can be seen. The parting plane 14 between the core half 12 and the die half 13 of the injection mold 11 is clearly visible. The cavity 16 runs along this parting plane 14 and is here a negative of the container wall 1, ie when plastic is injected into the cavity 16 and solidifies there by cooling the injection mold 11, a container in the shape of the container wall 1 is produced.

[0039] The present injection mold 11 is suitable for two-component injection molding. The separate injection points required for this are supplied with the first plastic component and the second plastic component 9 via the first injection unit 15 and the second injection unit 17, respectively.

[0040] The first injection unit 15 comprises two hot runners with needle valves (not visible), through which the first plastic component is injected into the cavity 16 in a first shot. The second injection unit 17 comprises four injection nozzles 18, one for each window 10 of the container. They are also mounted in the die half 13 of the injection mold 11, which remains in place during the manufacturing process and in particular during demolding of a finished container, while the core half 12 is moved to open and close the cavity 16. To avoid sprues, which are suboptimal due to the associated material loss, the injection nozzles 18 of the second injection unit 17 are also equipped with hot runners and needle valves (not visible). The latter ensure that the injection points in the windows 10 are barely visible from the outside.

[0041] During the first shot, i.e. during injection of the first plastic component, the cavity 16 has the outlines of the skeleton 5 without the window 10, although the cavity formed between the core half 12 and the die half 13 corresponds overall to the shape of the entire container wall 1.

[0042] For this purpose, the cavity 16 for the first shot, which corresponds to the shape of the skeleton 5, is reduced in size by frame-shaped, movable shut-off elements 19. These prevent the first plastic component from entering the cavity during the first shot, which is to be occupied by the second plastic component 9 in the finished container.

[0043] The Figure 4 shows a schematic representation of the Figure 3right-hand side of the injection mold 11, with the die half 13 omitted. This illustrates the position of the second injection unit 17 relative to the container windows 10. It also shows that the shut-off elements 19 are composed of a contour frame 20 and a pressing frame 21, which can be moved in steps from the core half 12.

[0044] In the Figures 5 and 6 which the detail X from Figure 3 show, the shut-off elements 19 are shown at two different times when carrying out the method according to the invention, wherein Figure 5 the situation when injecting the first plastic component and Figure 6 the situation when injecting the second plastic component.

[0045] As can be seen from the Figures 5 and 6As can be seen, the movable shut-off elements 19 consist not only of the contour frame 20 and the pressing frame 21, but also comprise a stop frame plate 22 which, together with ejector bolts (not shown), ensures a stepped movement of the contour frame 20 and the pressing frame 21 and provides support against the injection pressure.

[0046] To inject the first plastic component, i.e. for the first shot, the pressing frame 21 locks, as shown in Figure 5shown, the cavity 16 against the hollow space, which is later to become the window 10, in such a way that the first plastic component, which in this illustration flows from above into the cavity 16, is stopped on the press-on frame 21 to form the skeleton 5. The contour frame 20 is half retracted or it has only been half carried along by the press-on frame 21, which is moved by the ejector bolts (not shown), due to a corresponding play between the press-on frame 21 and the contour frame 20, so that immediately next to the press-on frame 21 the cavity 16 is reduced to approximately half the clear width of the cavity 16.

[0047] For the second shot, i.e. for injecting the second plastic component 9, both the pressing frame 21 and the contour frame 20 are spring-loaded and completely retracted into the core half 12 until they stop against the stop frame plate 22 ( Figure 6), so that the cavity 16 expands to the overall shape of the container wall 1. The injection of the second plastic component 9 takes place via the second injection unit 17 from the window 10, so that the second plastic component 9 flows in the area of ​​the contour frame 20, in which a space has been created behind the already injected first plastic component (the skeleton 5), in this area behind the first plastic component, overlaps with it and in the overlap area creates a large-area material connection between the two plastic components, as shown in Figure 1 is visible.

[0048] Figure 7shows the result: The second plastic component 9 has flowed behind the skeleton 5 in an overlap area 23 and, upon solidification, has bonded there with the skeleton. The surface area of ​​this connection is, as can be seen at first glance, many times larger than it would be if the second plastic component 9 and the skeleton 5 were only butt-jointed.

[0049] In the Figures 8 to 13A further exemplary embodiment of the injection molding tool for producing a container according to the invention is illustrated in detailed sectional views. The difference from the exemplary embodiment described with reference to the previous figures lies in the mechanism for forming the transition region between the skeleton 5 with the first plastic component and the window 10 with the second plastic component. In this second exemplary embodiment, this transition region should have a plurality of separate overlapping regions distributed around the window 10, whereby a Figure 14The stability of the skeleton 5 in the transition area is significantly increased by the periodic alternation of overlapping areas with areas of undiminished material thickness, while the overlapping areas nevertheless create a sufficiently large connection surface between the first and second plastic components, which is much larger than a butt joint.

[0050] The cavity 16 is formed between the core half 12 and the die half 13 of the injection molding tool. In the present second exemplary embodiment, this cavity is reduced in size by multi-part, frame-shaped slides 24 for the first shot, i.e., the injection of the first plastic component into the cavity 16. To produce overlap regions 23 between the second plastic component, which forms the window 10, and the first plastic component, which forms the skeleton 5, pins 25 are used that are not rigidly connected to the slides 24. These pins 25 are arranged circumferentially distributed around the window 10 in order to create a plurality of circumferentially distributed, separate overlap regions 23 between the two plastic components. The required movements of the slides 24 and the pins 25 during the two-component injection molding process are effected by control slides 26 inside the core half 12.

[0051] The various process steps during the production of the second embodiment of a container according to the invention or during the use of the second embodiment of an injection molding tool are shown in the Figures 8 to 13 as follows: Figure 8 shows the starting position of the injection mold, with the core half 12 and the die half 13 already moved together to form a cavity 16 that has the shape of the container to be produced. The control slides 26 are retracted, as indicated by an arrow, whereby the slides 24 are also in a retracted position, holding the pins 25 in a likewise retracted position. The cavity 16 is therefore also open in the area of ​​the later windows 10 during the moving together of the core half 12 and the die half 13, as well as in the starting position shown here.

[0052] The control slide 26 moves in a cavity 27 and slides against a driver 28, via which it is operatively connected to the slide 24. The linear movement of the control slide 26 occurs along a direction that is not parallel, but at an acute angle to the outer surface of the slide 24 and thus not quite perpendicular to a direction of movement of the driver 28. A downward movement of the control slide 26, as in Figure 8 indicated, therefore causes a movement of the driver 28 towards the interior of the core half 12, in Figure 8 i.e., to the right (also indicated by an arrow), so that the control slide 26 holds the slide 24 in the starting position in a retracted state. The pin 25, in turn, is held in a retracted state by the slide 24.

[0053] How Figure 9shows, in preparation for the first shot, in which the first plastic component is injected into the cavity 16 from above, the control slide 26 is moved upwards, whereby it moves the driver 28 outwards, into Figure 9 i.e., to the left. At the end point of this movement, the control slide 26 strikes a beveled support surface 29 of the cavity 27, which braces it against the core half against the injection pressure of the first plastic component. The driver 28 also pushes the frame-shaped slide 24 outward, causing it to rest against the die half 13 and close the cavity 16 in the area of ​​the future windows 10. In the present example, the slide 24 travels 0.9 mm, viewed perpendicular to the plane of the windows 10, which ultimately corresponds to the later material thickness of the windows 10.

[0054] The pin 25, however, or rather the multitude of pins 25 distributed around the circumference of the frame-shaped slide 24, is only moved half this distance, i.e., 0.45 mm, so that it forms an overlap area 23 in which the cavity 16 is reduced by only half. This is achieved by the displaceability of the pin 25 in the slide 24, in conjunction with a spring load that presses the pin 25 toward the interior of the core half 12.

[0055] In the Figure 9 In the position shown, the pin 25 rests on its rear side against the slide 24, so that it can withstand the injection pressure during the first shot. The slide 24 itself can withstand the injection pressure because the control slide 26 ultimately rests positively on the relatively large support surface 29 in the core half 12.

[0056] Figure 10shows the situation after the first shot, i.e., after the first plastic component has been injected into the cavity 16, foamed there, and formed the skeleton 5. Due to the pins 25, the skeleton 5 has only half the material thickness present next to and between the pins 25 in the overlapping areas 23.

[0057] Now, how Figure 11 As illustrated, the control slide 26 is pulled downward, releasing it from the support surface 29 and, due to the movement geometry, displacing the driver 28 by 0.9 mm toward the interior of the core half 12. As a result, the frame-shaped slide 24 is drawn into the core half 12, taking the pins 25 with it, as these follow under spring load. This process opens the cavity 16 in the area of ​​the future window 10, as shown in Figure 11 In the overlapping areas 23, a "half" cavity is created.

[0058] How Figure 12shows, the windows 10 are then produced from the die half 13 by injecting a second plastic component into the cavity 16 which has been expanded by retracting the slide 24. In the overlapping areas 23, the same situation arises as that shown in Figure 7 is shown: The second plastic component has flowed in front of the skeleton 5 and, upon solidification, has bonded to it over a large area. However, the overlapping area 23 is not formed circumferentially around the slide 24, but rather separate overlapping areas 23 are produced circumferentially distributed on pins 25, which are cylindrical in shape here, so that in the transition area between the first and the second plastic component, the skeleton 5 is formed quasi-periodically alternating with full material thickness and with half material thickness in overlapping areas 23. The result is shown in Figure 14 to recognize.

[0059] Figure 13 Finally, it shows the ejection of the finished container by means of an ejector ring 30 arranged on the core half 12. The die half 13 (no longer visible here) was previously removed, or the core half 12 was moved out of the die half 13.

Claims

1. Container made of injection-molded plastic, consisting essentially of a container wall (1), which defines an interior (8) of the container, with a first plastic component, from which a skeleton (5) with a base surface (2) and a plurality of struts (6) and / or part surfaces (7) molded thereon is formed, and with at least one second plastic component (9) which completes the skeleton (5) to form the container wall (1), characterized in that the skeleton (5) consists of foamed plastic and the second plastic component (9) consists of a non-foamed plastic, and in that the second plastic component (9) is a transparent plastic.

2. Container according to claim 1, wherein the second plastic component (9) is connected to the first plastic component by means of a two-component injection molding technique.

3. Container according to claim 2, wherein the first and the second plastic component (9), as viewed perpendicular to a plane of the container wall (1), overlap at least partially in a transitional region (23) from the first to the second plastic component (9).

4. Container according to claim 3, wherein a plurality of separate overlapping areas are arranged in the transitional region (23), in which the first and the second plastic component (9) overlap, while they do not overlap outside these overlapping areas in the transitional area (23).

5. Container according to claim 4, wherein the separate overlapping areas are distributed around a circumference of the second plastic component (9).

6. Container according to at least one of the claims 1 to 5, wherein the skeleton (5) comprises a circumferential upper edge (4) of the container.

7. Container according to at least one of the claims 1 to 6, wherein the skeleton (5) has a material thickness of at least 2 mm, preferably of 2.5 mm to 4 mm, particularly preferably of 2.8 to 3.2 mm, and wherein the second plastic component (9) has a material thickness of at most 1.8 mm, preferably of at most 1.5 mm, particularly preferably of 0.8 to 1.2 mm.

8. Method for producing a container, in particular according to at least one of the claims 1 to 7, which is formed essentially from a container wall (1), which defines an interior (8) of the container, wherein a skeleton (5) with a base surface (2) and a plurality of struts (6) and / or part surfaces (7) formed thereon is molded from a first plastic component, in that the first plastic component is plasticized by heating, is injected under pressure via a first injection unit (15) into a cavity (16) of a dividable injection mold (11) forming the shape of the skeleton (5) with a core half (12) and a die half (13) and is solidified therein by cooling, wherein after injecting the first plastic component the cavity (16) is expanded to form the container wall (1), and wherein a second plastic component (9) is plasticized by heating, is injected under pressure via a second injection unit (17) into the expanded cavity (16) and is solidified therein by cooling, in order to complete the skeleton (5) to form the container wall (1), characterized in that the first plastic component is mixed with a gas before injecting, which expands in the cavity (16) during the injection process after leaving the first injection unit (15) and thereby causes the foaming of the first plastic component.

9. Method according to claim 8, wherein slides or movable shut-off elements (19) are used for widening the cavity (16), which are preferably arranged on the core half (12) of the injection mold (11).

10. Method according to claim 9, wherein the cavity (16) is widened in stages by multipart slides and / or shut-off elements (19) and / or pins that can be moved separately or in groups.

11. Method according to any one of claims 9 or 10, wherein the used second injection unit (17) is provided with at least one hot runner.

12. Method for producing a container, in particular according to at least one of the claims 1 to 7, which is formed essentially by a container wall (1), which defines an interior (8) of the container, wherein a skeleton (5) with a base surface (2) and a plurality of struts (6) and / or part surfaces (7) formed thereon is molded from a first plastic component, in that the first plastic component is plasticized by heating, is injected under pressure into a cavity (16) of a first dividable injection mold (11) forming the shape of the skeleton (5) and is solidified therein by cooling, after which the skeleton (5) is transferred into a second dividable injection mold, the cavity of which has the form of the container wall (1), and wherein a second plastic component (9) is plasticized by heating, is injected under pressure into the cavity of the second dividable injection mold and is solidified therein by cooling, in order to complete the skeleton (5) located in the cavity to form the container wall (1), characterized in that the first plastic component is mixed with a gas before injecting, which expands in the cavity (16) during the injection process after leaving the first injection unit (15) and thereby causes the foaming of the first plastic component.

13. Method according to at least one of the claims 8 to 12, wherein the first injection unit (15) used comprises a valve with a needle closure.

14. Method according to at least one of the claims 8 to 13, wherein carbon dioxide is used as the gas.